Research studies suggest that Thymosin Beta 4 may exhibit some potential to modulate actin dynamics, a process that is potentially responsible for cell movement and maintaining structural integrity. This property seems to be particularly relevant in cellular processes such as cell migration and tissue repair. Moreover, Thymosin Beta 4 is hypothesized to inhibit inflammatory cytokines and possibly reduce oxidative stress, which may contribute to its protective potential at a cellular level of cardiac cells.^[1]

Research also posits that Thymosin Beta 4 might stimulate stem cell differentiation and possibly angiogenesis (the formation of new blood vessels), which are thought to be crucial processes in the life cycle of cells including cardiac cells. More specifically, it’s been proposed that Thymosin Beta 4 might interact with cardiac progenitor cells, and stimulate their migration. Hypothetically, this peptide might also affect processes such as cardiac cell proliferation or survival, which are also key aspects of potentially facilitating faster cardiac regeneration.^[2]

Thymosin Beta 4 Peptide Potential Mechanism of Action

The mechanisms of action for Thymosin Beta 4 are still being explored. Nevertheless, there are some preliminary insights into its potential activity. For example, it seems to function as an actin-binding protein that may inhibit the polymerization of globular actin (G-actin) into filamentous actin (F-actin). This process is known as actin sequestration, which could potentially cause in elevated G-actin levels.^{[3] [4] [5]} Actin, which appears to be a major component of the cellular cytoskeleton including cardiac cells, may provide structural support to cells and is involved in various cellular processes, including cardiac cell motility to facilitate regeneration. Thymosin Beta 4 is thought to bind with actin primarily (but not exclusively) via its central actin-binding domain (aa 17-23), also known as Ac-LKKTETQ.^[6] Researchers posit that “thymosin beta(4) has the potential for significant roles in tissue development, maintenance, repair, and pathology” including cardiac regeneration. The potential prevention of F-actin polymerization by Thymosin Beta 4 might alter the cellular cytoskeleton, which could affect the ability of cardiac cells to move and change shape. This process could have implications in various physiological and pathological processes where cardiac cell motility is crucial, such as cardiac regeneration.^[7] It’s important to note that these mechanisms are hypothesized to explain the potential action of intracellular Thymosin Beta 4.

Additionally, TB4 may also hold potential when present outside of cardiac cells (extracellularly).^[8] Some research in blood vessel cells suggests that the influence of extracellular Thymosin Beta 4 might regulate processes such as cardiac cell motility and angiogenesis. Scientists posit that the peptide might regulate these processes by interacting with cell surface-located ATP synthase enzymes. These are cellular enzymes considered to be involved in the energy production of the cardiac and other cells.^[9] Extracellular Thymosin Beta 4 might also potentially become oxidized in sites of inflammation to Thymosin Beta 4 sulfoxide, and the latter is thought to have potent anti-inflammatory properties.^[10] Furthermore, Thymosin Beta 4 might also reduce inflammation by possibly increasing the expression of microRNA-146a (miR-146a). This could potentially decrease the expression of two pro-inflammatory cytokines, called L-1 receptor-associated kinase 1 (IRAK1) and tumor necrosis factor receptor-associated factor 6 (TRAF6).^[11] Apparently reducing inflammation and potentially stimulating cardiac cell motility is thought to play a major role in tissue regeneration, including cardiac recovery.

Thymosin Beta 4 Peptide and Regeneration of Cardiac Cells

Experimental studies suggest that endothelial progenitor cells (EPC) may have a potential for inducing cardiac regeneration, and the addition of TB4 appears to enhance this process. The researchers posited that EPC with addition of Thymosin Beta 4 peptide may have approved the apparent cardiac function in damaged myocardium and facilitated cardiac repair.^[12] This was likely due to its potential action on cardiac cell motility and apparent stimulation of cardiac cell progenitors. Thymosin Beta 4 may also have potentially contributed to cardiac regeneration by apparently reducing inflammation. The peptide has been suggested to potentially decrease reactive oxygen species (ROS) and lipid peroxidation while possibly increasing antioxidant levels. It may also inhibit the activation of nuclear factor kappa B, thus apparently suppressing pro-inflammatory cytokine production, and preventing fibrosis – a potentially undesired regeneration process known to impede tissue function.^[13] These findings suggest that Thymosin β4 and cardiac reprogramming technology might work synergistically to limit damage to the heart and promote cardiac regeneration, possibly also through the stimulation of endogenous cells within the heart. Thymosin Beta 4 might also promote myocardial survival in hypoxic conditions and apparently stimulates angiogenesis, which could potentially lead to cardiac repair. The researchers also propose a potential mechanism involving the reprogramming of cardiac fibroblasts to cardiomyocyte-like cells^[14] Ultimately, the authors commented that “thymosin β4 and cardiac reprogramming technology may synergistically limit damage to the heart and promote cardiac regeneration through the stimulation of endogenous cells within the heart.” A study in murine models of coronary artery ligation also reported that Thymosin Beta 4 application may upregulate integrin-linked kinase (ILK) and protein kinase B activity in the heart, potentially enhancing early myocyte survival and apparently improving cardiac function.^[15] The scientists also posited that “Thymosin Beta 4 peptide promotes myocardial and endothelial cell migration in the embryonic heart and retains this property in postnatal cardiomyocytes.”

Conclusion

In conclusion, Thymosin Beta 4 appears to have a complex and multifaceted role in cellular processes related to regeneration. That role appears to be particularly in relation to Thymosin Beta 4’s apparent potential on actin dynamics and cell motility including cardiac cells. Its potential influence on cardiac cells and its possible involvement in processes such as inflammation reduction and angiogenesis also suggest that it could play a significant role in cardiac regeneration. Most importantly, Thymosin Beta 4 may also upregulate cardiac cell progenitors, and via its apparent effects on cell motility, it may aid their relocation to injury sites for recovery and regeneration.

However, these are preliminary findings and the exact mechanisms of Thymosin Beta 4’s action, both intracellularly and extracellularly, remain to be fully elucidated. The apparent action of TB4 in the context of cardiac cell regeneration is particularly intriguing, but further research is needed to substantiate these claims and to explore the full range of Thymosin Beta 4’s potential.

Disclaimer: The products mentioned are not intended for human or animal consumption. Research chemicals are intended solely for laboratory experimentation and/or in-vitro testing.  Bodily introduction of any sort is strictly prohibited by law.  All purchases are limited to licensed researchers and/or qualified professionals. All information shared in this article is for educational purposes only.

References

1. Goldstein, A. L., Hannappel, E., Sosne, G., & Kleinman, H. K. (2012). Thymosin β4: a multi-functional regenerative peptide. Basic properties and clinical applications. Expert opinion on biological therapy, 12(1), 37–51. https://doi.org/10.1517/14712598.2012.634793
2. Choudry, F. A., Yeo, C., Mozid, A., Martin, J. F., & Mathur, A. (2015). Increases in plasma Tβ4 after intracardiac cell therapy in chronic ischemic heart failure is associated with symptomatic improvement. Regenerative medicine, 10(4), 403–410. https://doi.org/10.2217/rme.15.9
3. Sanders, M. C., Goldstein, A. L., & Wang, Y. L. (1992). Thymosin Beta 4 (Fx peptide) is a potent regulator of actin polymerization in living cells. Proceedings of the National Academy of Sciences of the United States of America, 89(10), 4678–4682. https://doi.org/10.1073/pnas.89.10.4678
4. Irobi, E., Aguda, A. H., Larsson, M., Guerin, C., Yin, H. L., Burtnick, L. D., Blanchoin, L., & Robinson, R. C. (2004). Structural basis of actin sequestration by thymosin-beta4: implications for WH2 proteins. The EMBO journal, 23(18), 3599–3608. https://doi.org/10.1038/sj.emboj.7600372
5. Belsky, J. B., Rivers, E. P., Filbin, M. R., Lee, P. J., & Morris, D. C. (2018). Thymosin Beta 4 regulation of actin in sepsis. Expert opinion on biological therapy, 18(sup1), 193-197.
6. Sosne, G., Qiu, P., Goldstein, A. L., & Wheater, M. (2010). Biological activities of thymosin beta4 defined by active sites in short peptide sequences. FASEB journal : official publication of the Federation of American Societies for Experimental Biology, 24(7), 2144–2151. https://doi.org/10.1096/fj.09-142307
7. Yadav, T., Gau, D., & Roy, P. (2022). Mitochondria-actin cytoskeleton crosstalk in cell migration. Journal of cellular physiology, 237(5), 2387–2403. https://doi.org/10.1002/jcp.30729
8. Huff, T., Müller, C. S., Otto, A. M., Netzker, R., & Hannappel, E. (2001). beta-Thymosins, small acidic peptides with multiple functions. The international journal of biochemistry & cell biology, 33(3), 205–220. https://doi.org/10.1016/s1357-2725(00)00087-x
9. Freeman, K. W., Bowman, B. R., & Zetter, B. R. (2011). Regenerative protein thymosin beta-4 is a novel regulator of purinergic signaling. FASEB journal : official publication of the Federation of American Societies for Experimental Biology, 25(3), 907–915. https://doi.org/10.1096/fj.10-169417
10. Young, J. D., Lawrence, A. J., MacLean, A. G., Leung, B. P., McInnes, I. B., Canas, B., Pappin, D. J., & Stevenson, R. D. (1999). Thymosin Beta 4 sulfoxide is an anti-inflammatory agent generated by monocytes in the presence of glucocorticoids. Nature medicine, 5(12), 1424–1427. https://doi.org/10.1038/71002
11. Santra, M., Zhang, Z. G., Yang, J., Santra, S., Santra, S., Chopp, M., & Morris, D. C. (2014). Thymosin β4 up-regulation of microRNA-146a promotes oligodendrocyte differentiation and suppression of the Toll-like proinflammatory pathway. The Journal of biological chemistry, 289(28), 19508–19518. https://doi.org/10.1074/jbc.M113.529966
12. Zhu, J., Song, J., Yu, L., Zheng, H., Zhou, B., Weng, S., & Fu, G. (2016). Safety and efficacy of autologous thymosin β4 pre-treated endothelial progenitor cell transplantation in patients with acute ST segment elevation myocardial infarction: A pilot study. Cytotherapy, 18(8), 1037–1042. https://doi.org/10.1016/j.jcyt.2016.05.006
13. Shah, R., Reyes-Gordillo, K., Cheng, Y., Varatharajalu, R., Ibrahim, J., & Lakshman, M. R. (2018). Thymosin β4 Prevents Oxidative Stress, Inflammation, and Fibrosis in Ethanol- and LPS-Induced Liver Injury in Mice. Oxidative medicine and cellular longevity, 2018, 9630175. https://doi.org/10.1155/2018/9630175
14. Srivastava, D., Ieda, M., Fu, J., & Qian, L. (2012). Cardiac repair with thymosin β4 and cardiac reprogramming factors. Annals of the New York Academy of Sciences, 1270, 66–72. https://doi.org/10.1111/j.1749-6632.2012.06696.x
15. Bock-Marquette, I., Saxena, A., White, M. D., Dimaio, J. M., & Srivastava, D. (2004). Thymosin beta4 activates integrin-linked kinase and promotes cardiac cell migration, survival and cardiac repair. Nature, 432(7016), 466–472. https://doi.org/10.1038/nature03000

According to laboratory research, Chonluten (T-34) may be derived from respiratory lung tissue, more specifically mucosa.^[1] There, Chonluten is considered to normalize the performance of bronchial mucous membrane cells by potentially regulating genes related to inflammation, antioxidant activity, and proliferation. The peptide may also potentially improve the regeneration of cells in the gastrointestinal system.^[2]

Chonluten (T-34) Mechanisms of Action

The peptide likely achieves its potential for regulating gene expression thanks to its small size, which may allow it to penetrate the cell’s nuclei. Researchers report that “Short peptides, consisting of 2-7 amino acid residues, can penetrate into the nuclei and nucleoli of cells and interact with the nucleosome, the histone proteins, and both single- and double-stranded DNA. DNA-peptide interactions, including sequence recognition in gene promoters, are important for template-directed synthetic reactions, replication, transcription, and reparation. Peptides can regulate the status of DNA methylation, which is an epigenetic mechanism for the activation or repression of genes“.^{[3] [4] [5]} However, it is important to note that the aforementioned researchers have shared this information for short-peptides in general and not for Chonluten per se.

Chonluten and Anti-Inflammatory Mechanisms

Chonluten may potentially activate the phosphorylation of STAT molecules, particularly STAT1, in macrophage cells. This activation appears to occur independently of receptor-associated kinases. STAT1, a transcription factor involved in signal transduction and gene expression regulation, potentially cooperates with receptor-associated kinases to facilitate the transfer of cytokine-mediated biological responses into the nuclei.^[1] 

It is hypothesized that Chonluten may potentially downregulate the phosphorylation of STAT3, another transcription factor involved in cellular signaling. STAT3 is considered to be associated with acute inflammatory stimuli and may play a role in the transcription of IL-6, a key cytokine in the acute phase response during inflammation and infectious diseases. By modulating STAT3 phosphorylation, Chonluten could affect the transcriptional activity of IL-6 and influence the inflammatory response.^[1]

Moreover, Chonluten (T-34) research has posited its possible efficacy in decreasing the levels of IL-6, TNF (tumor necrosis factor), and IL-17 in macrophages activated by lipopolysaccharide (LPS), a component of bacterial cell walls. IL-6 is a pro-inflammatory cytokine involved in immune responses, while TNF and IL-17 are also pro-inflammatory cytokines that contribute to inflammation and immune system regulation. Chonluten’s potential ability to downregulate the production of these cytokines suggests its possible role in dampening pro-inflammatory processes in activated macrophages. More specifically, the researchers comment that “tripeptide, derived from bronchial epithelial cells, inhibited in vitro tumor necrosis factor (TNF) production of monocytes exposed to pro-inflammatory bacterial lipopolysaccharide (LPS). The low TNF release by monocytes is linked to a documented mechanism of TNF tolerance, promoting attenuation of inflammatory action.“^[1] 

Additionally, Chonluten may attenuate the adhesion mechanism between endothelium (the inner lining of blood vessels) and immune cells. This observation was made in co-incubation experiments with LPS-activated endothelial cells. By modulating this adhesion mechanism, Chonluten might influence immune cell migration and trafficking, essential in inflammation and immune responses.^[1]

Chonluten (T-34) and Gastric Cell Regeneration

Chonluten appears to have the potential to enhance gastrointestinal cell regeneration by potentially regulating the expression of genes associated with antioxidant enzymes, such as superoxide dismutase (SOD). Research conducted on the peptide has suggested this ability through the compound apparently normalizing the expression of these genes, through which Chonluten seemingly aids in restoring the balance of antioxidant defense mechanisms in the gastric mucosa. This regulatory action on antioxidant systems may contribute to a potential reduction in oxidative stress and promote cell regeneration.^[2]

Furthermore, it is hypothesized that the Chonluten peptide may have an anti-inflammatory potential by influencing the expression of genes involved in the inflammatory response, such as TNF-α and cyclooxygenase-2 (Cox-2). By potentially reducing the expression of these inflammatory mediators, the Chonluten peptide supposedly assists in controlling inflammation in the gastric mucosa, thus facilitating the cell regeneration process.^[2] 

Moreover, the Chonluten may possibly stimulate granulation tissue formation, which is crucial for tissue repair. It may stimulate the proliferation of fibroblasts and the growth of blood vessels within the granulation tissue and also may facilitate the regeneration of damaged gastric mucosa. Additionally, Chonluten may promote the epithelialization of the ulcer by the apparent stimulation of the proliferation of epithelial cells, potentially leading to the closure of the ulcer defect.^[2]

It is also posited that Chonluten (T-34) may exhibit a reparative action by potentially reducing excessive apoptosis (programmed cell death) in the gastric mucosa. It has been suggested by researchers to possibly regulate the expression of heat shock protein 70 (HSP70), which is believed to play a role in protecting cells from apoptotic stimuli. By modulating HSP70 expression, the peptide might help prevent excessive cell apoptosis and potentially promote tissue survival and repair.^[2]

In contrast, additional studies have reported that Chonluten may have insignificant potential for the proliferation of other cell lines, such as skin cell lines.^[6] Therefore, more research is needed to delve into the potential mechanisms and actions of Chonluten.

Conclusion

In conclusion, Chonluten, a short peptide consisting of three amino acids, appears to hold promising potential as a bioregulator of gene expression. The mechanisms of action of Chonluten suggest that it may have the ability to penetrate cell nuclei and potentially interact with DNA, hypothetically regulating gene activation or repression. Further, Chonluten (T-34) seemingly exhibits anti-inflammatory properties by modulating the phosphorylation of transcription factors involved in cytokine-mediated responses and potentially reducing the production of pro-inflammatory cytokines. Some studies also suggest that Chonluten might promote gastric cell regeneration by regulating antioxidant enzyme expression, controlling inflammatory mediators, stimulating tissue formation and epithelialization, and preventing excessive apoptosis, but more research is needed. Overall, further investigation is required to fully understand the potential of Chonluten on other cell lines and cell cultures. 

Disclaimer: The products mentioned are not intended for human or animal consumption. Research chemicals are intended solely for laboratory experimentation and/or in-vitro testing.  Bodily introduction of any sort is strictly prohibited by law.  All purchases are limited to licensed researchers and/or qualified professionals. All information shared in this article is for educational purposes only.

References

1. Avolio, F., Martinotti, S., Khavinson, V. K., Esposito, J. E., Giambuzzi, G., Marino, A., Mironova, E., Pulcini, R., Robuffo, I., Bologna, G., Simeone, P., Lanuti, P., Guarnieri, S., Trofimova, S., Procopio, A. D., & Toniato, E. (2022). Peptides Regulating Proliferative Activity and Inflammatory Pathways in the Monocyte/Macrophage THP-1 Cell Line. International journal of molecular sciences, 23(7), 3607. https://doi.org/10.3390/ijms23073607
2. Khavinson, V. K.h, Lin’kova, N. S., Dudkov, A. V., Polyakova, V. O., & Kvetnoi, I. M. (2012). Peptidergic regulation of expression of genes encoding antioxidant and anti-inflammatory proteins. Bulletin of experimental biology and medicine, 152(5), 615–618. https://doi.org/10.1007/s10517-012-1590-2
3. Khavinson, V. K., Popovich, I. G., Linkova, N. S., Mironova, E. S., & Ilina, A. R. (2021). Peptide Regulation of Gene Expression: A Systematic Review. Molecules (Basel, Switzerland), 26(22), 7053. https://doi.org/10.3390/molecules26227053
4. Khavinson, V. K., Lin’kova, N. S., & Tarnovskaya, S. I. (2016). Short Peptides Regulate Gene Expression. Bulletin of experimental biology and medicine, 162(2), 288–292. https://doi.org/10.1007/s10517-016-3596-7
5. Fedoreyeva, L. I., Kireev, I. I., Khavinson, V. K.h, & Vanyushin, B. F. (2011). Penetration of short fluorescence-labeled peptides into the nucleus in HeLa cells and in vitro specific interaction of the peptides with deoxyribooligonucleotides and DNA. Biochemistry. Biokhimiia, 76(11), 1210–1219. https://doi.org/10.1134/S0006297911110022
6. Voicekhovskaya, M. A., Chalisova, N. I., Kontsevaya, E. A., & Ryzhak, G. A. (2012). Effect of bioregulatory tripeptides on the culture of skin cells from young and old rats. Bulletin of experimental biology and medicine, 152(3), 357–359. https://doi.org/10.1007/s10517-012-1527-9

The CJC-1295 and GHRP-6 blend may exhibit a potentially synergistic action on cells involved in growth hormone release. Combining these peptides may enhance both the amplitude and the frequency of the growth hormone pulses by somatotroph cells. This synergistic action is believed to be mediated through complementary mechanisms of action, as CJC-1295 appears to target the GHRH receptor pathway, while GHRP-6 may act on the ghrelin receptor pathway.

CJC-1295 & GHRP-6 Blend Structure and Affinity

CJC-1295, also known as tetra-substituted GRF (1-29), appears to be a synthetic peptide analog of the endogenous GHRH hormone. It comprises the shortest amino-acid chain that may possess an affinity to the GHRH receptors, and consists of the first 29 amino acids of GHRH. CJC-1295 appears to be modified as it has 4 of the original 29 amino acids replaced to potentially make the peptide more resistant to rapid cleavage by the enzyme dipeptidyl peptidase-4 and other peptides that appear to result in peptide inactivation^[1]. More specifically, the amino acids that appear to be modified and replaced are the 2nd, 8th, 15th, and 27th amino acids. In addition, CJC-1295 has undergone modification by including a drug affinity complex (DAC) component, which may potentially bind to plasma proteins. The DAC component specifically refers to the attachment of a derivative of lysine called N-epsilon-3-maleimidopropionamide at the C terminus of CJC-1295. This combination of modified amino acid sequence and a DAC component may potentially enhance the pharmacokinetics of CJC-1295, while still maintaining an apparent affinity to the GHRH receptors. Indeed, scientists have commended that the peptide “was found to be present in plasma beyond 72 h.”^[2]

On the other hand, GHRP-6 is a hexapeptide that appears to belong to the class of synthetic growth hormone-releasing peptides, which may act by potentially binding to the ghrelin receptor on the surface of pituitary cells and certain hypothalamic neurons. Upon binding, GHRP-6 appears to stimulate the so-called growth hormone secretagogue receptor (GHS-R1a). These receptors are also sometimes termed the ghrelin receptors, as ghrelin appears to be their main natural ligand. GHRP-6 appears to bind to these receptors, and may induce an intracellular calcium response and protein kinase C activity.^[3] By activating them, GHRP-6 appears to stimulate the production of growth hormones in pituitary cells. In addition, GHRP-6 may also have an affinity for the CD36 receptors.^[4] These CD36 receptors may serve multiple roles, including a potential action in lipid metabolism, acting as a scavenger receptor for lipids, facilitating their uptake, and potentially modulating immune responses, regulating phagocytosis and inflammation. CD36 pathways may also play a potential role in angiogenesis regulation.

CJC-1295 & GHRP-6 Blend and Somatotroph Cells

CJC-1295 appears to target somatotroph cells by potentially interacting with the GHRH receptor they express. More specifically, CJC-1295 may bind to specific binding sites on the receptor protein, leading to conformational changes in the receptor structure and potentially initiating a cascade of molecular events. These events appear initiated by intracellular signaling proteins acting as potential molecular switches.^[5] These are the so-called G-proteins, which, once activated, may stimulate the potential production of second messengers like cyclic adenosine monophosphate (cAMP) or inositol trisphosphate (IP3).^[6] Second messengers like cAMP may activate protein kinases, enzymes that are considered to modify specific proteins. These kinases have a regulatory potential towards cellular processes and may phosphorylate transcription factors, or proteins controlling gene expression. Phosphorylated transcription factors may enter the nucleus of somatotroph cells, potentially influencing genes related to growth hormone synthesis.^[7] Ultimately, CJC-1295 binding appears to trigger events leading to the release of growth hormone from vesicles by the somatotroph cells. Researchers comment that the peptide may upregulate growth hormone production by somatotrophs, thus apparently contributing “to an overall increase in GH secretion … by 46%.” In turn, growth hormone appears to have a major anabolic mediator called insulin-like growth factor-1 (IGF-1). IGF-1 levels also apparently increased by 45%.^[7] Another trial suggests that CJC-1295 may potentially upregulate “GH concentrations by 2- to 10-fold.”^[8]

In contrast, GHRP-6 appears to interact with somatotroph cells via the  GHS-R1a. More specifically, scientists posit that the peptide may apparently prefer an intracellular calcium response and protein kinase C activity instead of cAMP production.^[9] The GHS-R1a activation appears to activate a specific unit of G-proteins inside somatotrophs. Gαq/11. This potentially preferred pathway by GHRP-6 apparently involves the enzyme phospholipase C. Gαq/11 may bind to phospholipase C, which may cleave a phospholipid called PIP2 into two messengers: the aforementioned IP3 and diacylglycerol (DAG).^[10] IP3 appears to bind to receptors on the endoplasmic reticulum, releasing calcium ions, while DAG may activate protein kinase C, phosphorylating signaling molecules and amplifying the cascade. This potentially leads to the release of growth hormones by somatotroph cells.

Conclusion

In conclusion, the CJC-1295 & GHRP-6 blend may have a synergistic potential as they appear to interact with receptors in the central nervous system, particularly in the pituitary gland cells called somatotrophs. These peptides are hypothesized to have neuroendocrine actions and stimulate the release of growth hormones from the aforementioned somatotrophs. CJC-1295 appears to bind the GHRH receptors in the pituitary gland, potentially leading to conformational changes and the activation of intracellular signaling pathways for growth hormone production. On the other hand, GHRP-6 may bind to the GHS-R1a receptors, also known as ghrelin receptors, with a potential preference for an intracellular calcium response and protein kinase C activity instead of cAMP production. This may also initiate a cascade of molecular events, potentially resulting in the release of growth hormones. 

Disclaimer: The products mentioned are not intended for human or animal consumption. Research chemicals are intended solely for laboratory experimentation and/or in-vitro testing.  Bodily introduction of any sort is strictly prohibited by law.  All purchases are limited to licensed researchers and/or qualified professionals. All information shared in this article is for educational purposes only.

References

1. Scarborough, R., Gulyas, J., Schally, A. V., & Reeves, J. J. (1988). Analogs of growth hormone-releasing hormone induce release of growth hormone in the bovine. Journal of animal science, 66(6), 1386–1392. https://doi.org/10.2527/jas1988.6661386x
2. Jetté, L., Léger, R., Thibaudeau, K., Benquet, C., Robitaille, M., Pellerin, I., Paradis, V., van Wyk, P., Pham, K., & Bridon, D. P. (2005). Human growth hormone-releasing factor (hGRF)1-29-albumin bioconjugates activate the GRF receptor on the anterior pituitary in rats: identification of CJC-1295 as a long-lasting GRF analog. Endocrinology, 146(7), 3052–3058. https://doi.org/10.1210/en.2004-1286
3. Sun, Q., Ma, Y., Zhang, L., Zhao, Y. F., Zang, W. J., & Chen, C. (2010). Effects of GH secretagogues on contractility and Ca2+ homeostasis of isolated adult rat ventricular myocytes. Endocrinology, 151(9), 4446–4454. https://doi.org/10.1210/en.2009-1432
4. Demers, A., McNicoll, N., Febbraio, M., Servant, M., Marleau, S., Silverstein, R., & Ong, H. (2004). Identification of the growth hormone-releasing peptide binding site in CD36: a photoaffinity cross-linking study. The Biochemical journal, 382(Pt 2), 417–424. https://doi.org/10.1042/BJ20040036
5. Martin, B., Lopez de Maturana, R., Brenneman, R., Walent, T., Mattson, M. P., & Maudsley, S. (2005). Class II G protein-coupled receptors and their ligands in neuronal function and protection. Neuromolecular medicine, 7(1-2), 3–36. https://doi.org/10.1385/nmm:7:1-2:003
6. Newton, A. C., Bootman, M. D., & Scott, J. D. (2016). Second Messengers. Cold Spring Harbor perspectives in biology, 8(8), a005926. https://doi.org/10.1101/cshperspect.a005926
7. Ionescu, M., & Frohman, L. A. (2006). Pulsatile secretion of growth hormone (GH) persists during continuous stimulation by CJC-1295, a long-acting GH-releasing hormone analog. The Journal of clinical endocrinology and metabolism, 91(12), 4792–4797. https://doi.org/10.1210/jc.2006-1702
8. Teichman, S. L., Neale, A., Lawrence, B., Gagnon, C., Castaigne, J. P., & Frohman, L. A. (2006). Prolonged stimulation of growth hormone (GH) and insulin-like growth factor I secretion by CJC-1295, a long-acting analog of GH-releasing hormone, in healthy adults. The Journal of clinical endocrinology and metabolism, 91(3), 799–805. https://doi.org/10.1210/jc.2005-1536
9. Sinha, D. K., Balasubramanian, A., Tatem, A. J., Rivera-Mirabal, J., Yu, J., Kovac, J., Pastuszak, A. W., & Lipshultz, L. I. (2020). Beyond the androgen receptor: the role of growth hormone secretagogues in the modern management of body composition in hypogonadal males. Translational andrology and urology, 9(Suppl 2), S149–S159. https://doi.org/10.21037/tau.2019.11.30
10. Bill, C. A., & Vines, C. M. (2020). Phospholipase C. Advances in experimental medicine and biology, 1131, 215–242. https://doi.org/10.1007/978-3-030-12457-1_9

BPC-157, also known as L 14736, PL-10, and bepecin, is a much shorter peptide comprising 15 amino acids. This pentadecapeptide is fully synthetic, but its structure is derived from the biologically active sequence of another peptide naturally found in gastric juices. BPC-157 may be associated with various cellular processes and is believed to play a role in tissue repair. It is thought to interact with signaling pathways within cells, potentially influencing factors involved in regeneration and recovery. Some studies suggest that BPC-157 may also have the ability to promote angiogenesis and modulate inflammatory processes.^[2] Additionally, it has been suggested by experimental models that BPC-157 might contribute to the protection and regeneration of different cells and tissues.

BPC-157 & TB-500 Blend Mechanisms of Action

BPC-157 & TB-500 appear to have different mechanisms, despite their similar potential. For example, TB-500 (Tβ4) appears to regulate the cellular actin-cytoskeleton and cellular migration by sequestering G-actin.^{[3] [4]} Furthermore, studies suggest that there appears to be a specific signaling pathway involved with damaged tissues that TB-500 may regulate. For instance, researchers have conducted experiments using cell models and observed that TB-500 potentially increases the expression of microRNA-146a (miR-146a), which might be a negative regulator of specific signaling pathways in cells. It appeared that this resulted in TB-500 possibly decreasing the expression of two proinflammatory cytokines associated with the aforementioned signaling pathways – L-1 receptor-associated kinase 1 (IRAK1) and tumor necrosis factor receptor-associated factor 6 (TRAF6). As a further suggestion that the increased expression of miR-146a may be TB-500’s main mechanism of action, the researchers commented that “transfection of anti-miR-146a nucleotides reversed the inhibitory effect of Tβ4 on IRAK1 and TRAF6.“^[5]  

On the other hand, BPC-157 appears to exert its actions via multiple mechanisms, which may include nitric oxide synthesis, regulating cells involved in tissue repair, growth factors, and inflammation. There is a possibility that BPC-157 interacts with the NO system, potentially offering protection to the endothelium and possibly inducing angiogenic action by promoting the formation of new blood vessels.^[6] It may have the potential to stimulate the expression of the early growth response 1 gene, which might be responsible for generating cytokines and growth factors, and perhaps facilitating the early formation of the extracellular matrix, including collagen. It should be noted that BPC-157’s interaction with nerve growth factor 1-A binding protein-2 might have repressive effects on certain factors. However, further research is needed to fully understand and confirm these potential mechanisms of BPC-157.

BPC-157 & TB-500 Blend and the Musculoskeletal System

The BPC-157 & TB-500 appear to both have the potential for speeding up the regeneration of connective tissue, such as the one found in tendons and ligaments. In one murine study, TB-500 was investigated for its potential on ligament recovery and regeneration.^[7] The scientists performed histological analysis to compare TB-500 against a placebo in a model of ligament injury. They commended that TB-500 may have induced the formation of a more uniform and evenly spaced bundles of collagen fibers within the granulation tissue that also have larger diameters compared to the control. Furthermore, the mechanical properties of the regenerating tissues, including the femur-medial collateral ligament-tibia complexes, appeared to be improved in the TB-500 group compared to the control.

Another study explored the potential impact of BPC 157 on the outgrowth of tendon fibroblasts from cultured tendon explants.^[8] The findings suggested that BPC 157 possibly enhanced the outgrowth of tendon explants. BPC 157 potentially increased the survival of these cells under H(2)O(2) stress. Furthermore, the researchers commented that “BPC 157 markedly increased the in vitro migration of tendon fibroblasts in a dose-dependent manner as revealed by transwell filter migration assay. BPC 157 also dose-dependently accelerated the spreading of tendon fibroblasts on culture dishes.” This effect was potentially associated with the induction of F-actin formation, as evidenced by FITC-phalloidin staining. The study also investigated the potential involvement of the FAK-paxillin (two focal adhesion–associated proteins that transmit signals downstream of integrins) pathway in mediating the potential of BPC 157. Western blot analysis suggested that the phosphorylation levels of both FAK and paxillin were apparently increased by BPC 157, while the total amounts of protein remained unchanged.

Conclusion

In summary, the BPC-157 & TB-500 blend shows a synergistic research potential. TB-500 may be involved in regulating cell migration, differentiation, and repair, potentially promoting angiogenesis and connective tissue regeneration. Furthermore, BPC-157 is also believed to have a potential in cellular repair, possibly by influencing factors involved in the normal recovery process. These peptides appear to have different mechanisms of action, with TB-500 possibly regulating cellular actin-cytoskeleton and migration, while BPC-157 may interact with various processes such as nitric oxide synthesis, growth factors, and inflammation regulation. Both peptides show potential in speeding up the regeneration of connective tissue, such as tendons and ligaments, with TB-500 potentially improving collagen fiber formation and regeneration and BPC-157 potentially enhancing tendon fibroblast outgrowth and migration. Further research is needed to confirm these mechanisms.

Disclaimer: The products mentioned are not intended for human or animal consumption. Research chemicals are intended solely for laboratory experimentation and/or in-vitro testing.  Bodily introduction of any sort is strictly prohibited by law.  All purchases are limited to licensed researchers and/or qualified professionals. All information shared in this article is for educational purposes only.

References

1. Maar, K., Hetenyi, R., Maar, S., Faskerti, G., Hanna, D., Lippai, B., Takatsy, A., & Bock-Marquette, I. (2021). Utilizing Developmentally Essential Secreted Peptides Such as Thymosin Beta-4 to Remind the Adult Organs of Their Embryonic State-New Directions in Anti-Aging Regenerative Therapies. Cells, 10(6), 1343. https://doi.org/10.3390/cells10061343
2. Seiwerth, S., Milavic, M., Vukojevic, J., Gojkovic, S., Krezic, I., Vuletic, L. B., Pavlov, K. H., Petrovic, A., Sikiric, S., Vranes, H., Prtoric, A., Zizek, H., Durasin, T., Dobric, I., Staresinic, M., Strbe, S., Knezevic, M., Sola, M., Kokot, A., Sever, M., … Sikiric, P. (2021). Stable Gastric Pentadecapeptide BPC 157 and Wound Healing. Frontiers in pharmacology, 12, 627533. https://doi.org/10.3389/fphar.2021.627533
3. Huff, T., Müller, C. S., Otto, A. M., Netzker, R., & Hannappel, E. (2001). beta-Thymosins, small acidic peptides with multiple functions. The international journal of biochemistry & cell biology, 33(3), 205–220. https://doi.org/10.1016/s1357-2725(00)00087-x
4. Sanders, M. C., Goldstein, A. L., & Wang, Y. L. (1992). Thymosin beta 4 (Fx peptide) is a potent regulator of actin polymerization in living cells. Proceedings of the National Academy of Sciences of the United States of America, 89(10), 4678–4682. https://doi.org/10.1073/pnas.89.10.4678
5. Santra, M., Zhang, Z. G., Yang, J., Santra, S., Santra, S., Chopp, M., & Morris, D. C. (2014). Thymosin β4 up-regulation of microRNA-146a promotes oligodendrocyte differentiation and suppression of the Toll-like proinflammatory pathway. The Journal of biological chemistry, 289(28), 19508–19518. https://doi.org/10.1074/jbc.M113.529966
6. Sikiric, P., Seiwerth, S., Rucman, R., Turkovic, B., Rokotov, D. S., Brcic, L., Sever, M., Klicek, R., Radic, B., Drmic, D., Ilic, S., Kolenc, D., Stambolija, V., Zoricic, Z., Vrcic, H., & Sebecic, B. (2012). Focus on ulcerative colitis: stable gastric pentadecapeptide BPC 157. Current medicinal chemistry, 19(1), 126–132. https://doi.org/10.2174/092986712803414015
7. Xu, B., Yang, M., Li, Z., Zhang, Y., Jiang, Z., Guan, S., & Jiang, D. (2013). Thymosin β4 enhances the healing of medial collateral ligament injury in rat. Regulatory peptides, 184, 1–5. https://doi.org/10.1016/j.regpep.2013.03.026
8. Chang, C. H., Tsai, W. C., Lin, M. S., Hsu, Y. H., & Pang, J. H. (2011). The promoting effect of pentadecapeptide BPC 157 on tendon healing involves tendon outgrowth, cell survival, and cell migration. Journal of applied physiology (Bethesda, Md. : 1985), 110(3), 774–780. https://doi.org/10.1152/japplphysiol.00945.2010

Hexarelin studies suggest its high selectivity for the ghrelin receptor, also known as the growth hormone secretagogue receptor 1a (GHSR1a). It appears to exhibit potent activity in stimulating growth hormone release, causing researchers to classify it as a growth hormone secretagogue. Its ability to selectively activate the GHSR1a sets it apart from other compounds in this class. Furthermore, Hexarelin is a unique peptide that appears to be resistant to degradation by digestive enzymes. Yet, the precise mechanisms of action and the full range of Hexarelin’s potential are not definitively established, and its specific interactions with growth hormone secretagogue receptors are still the subject of ongoing research.

Hexarelin Peptide and the Central Nervous System

Hexarelin, a peptide compound, appears to interact with the GHSR1a in the central nervous system, potentially initiating a cascade of intracellular signaling events that modulate various physiological processes. This interaction is hypothesized to occur due to the high affinity and specificity between Hexarelin and the binding site of GHSR1a receptors.

Research studies suggest that as Hexarelin binds to GHSR1a receptors, it may activate intracellular signaling pathways. These pathways are considered to involve molecular events, including the activation of G-proteins like Gαq/11, leading to the activation of phospholipase C (PLC). PLC induces the hydrolysis of phosphatidylinositol 4,5-bisphosphate (PIP2) into inositol triphosphate (IP3) and diacylglycerol (DAG). IP3 release may initiate the mobilization of intracellular calcium stores, potentially increasing cytosolic calcium levels.^{[1] [2]} This rise in calcium concentration may regulate cellular processes such as neurotransmitter release, gene expression, and intracellular signaling cascades. Additionally, DAG may activate protein kinase C (PKC), phosphorylating target proteins and potentially regulating cellular functions.

Activation of GHSR1a receptors by Hexarelin may lead to the release of specific hormonal substances from the pituitary gland. These potential substances include growth hormone (GH), prolactin, adrenocorticotropic hormone (ACTH), and cortisol.^{[3] [4]} Furthermore, the interaction between Hexarelin and GHSR1a receptors in the hippocampus potentially impacts neuronal function and communication. Its specific impact on cellular processes in the hippocampus is not fully understood but is suggested to play a role in the modulation of synaptic plasticity, neurotransmitter release, and mechanisms involved in memory consolidation and cognitive processes.

Furthermore, one study investigated the protective potential of Hexarelin peptide on the central nervous system, particularly the hippocampus. The study used a rat model of neonatal hypoxia-ischemia induced by carotid ligation and hypoxic exposure.^[5] The researchers commented that “damage was reduced by 39% in the treatment group, compared with the vehicle group, and injury was significantly reduced in the cerebral cortex, hippocampus, and thalamus but not in the striatum.” Moreover, the study reported that reduction in brain damage appeared to coincide with a decrease in caspase-3 activity, an enzyme involved in cell death, and an increase in the phosphorylation of Akt and glycogen synthase kinase-3beta. Overall, the activation of the Akt signaling pathway appeared to play a role in reducing cell death by modulating glycogen synthase kinase-3beta activity and possibly inhibiting caspase-dependent cell death. 

Hexarelin Peptide and the Ghrelin (GHSR1a) Receptors

Hexarelin peptide has complex potential interactions with the ghrelin receptors in the pituitary gland and the hypothalamus. Moreover, these interactions may be modified by other hormonal substances. For example, certain androgens may have the potential to upregulate ghrelin receptors, which could potentially enhance the response of these receptors to Hexarelin.^[6] It is hypothesized that androgens might modulate the expression or sensitivity of ghrelin receptors at the cellular level, although the precise mechanisms behind this interaction are not fully understood. It is possible that androgens could alter gene expression or intracellular signaling pathways, increasing the expression or sensitivity of ghrelin receptors. If this modulation occurs, it is speculated that Hexarelin may have a greater binding affinity to these upregulated receptors, potentially resulting in an amplified Hexarelin action and an apparent release of growth hormone.^[7]

Another factor that may potentially enhance the interaction between Hexarelin and the GHSR1a is the simultaneous activation of another receptor found on the pituitary gland, the growth hormone-releasing hormone (GHRH) receptor. For example, researchers have simultaneously tested Hexarelin (HEX) and the natural GHRH-receptor activator – GHRH.^[8] They commented that “the two substances induced a true synergistic effect, with GH release after HEX plus GHRH (…) being higher (…) than the arithmetic sum of the GH increases induced by each compound separately.” Other studies have also commented on similar findings.^{[9] [10]} This apparent synergism may be due to two potential mechanisms. Firstly, Hexarelin may potentially sensitize somatotroph cells in the pituitary gland, making them more responsive to the stimulatory action of GHRH. This increased sensitivity may lead to a higher potential for GH release when Hexarelin and GHRH are used together compared to using either compound alone. Secondly, both Hexarelin and GHRH may inhibit the release of somatostatin, a hormone that is considered to suppress GH secretion. By acting together, Hexarelin and GHRH may express a higher potential for somatostatin suppression, allowing for increased GH secretion.

Conclusion

In conclusion, Hexarelin peptide may have potential interactions with the ghrelin receptor (GHSR1a) in the central nervous system. Its proposed resistance to degradation by digestive enzymes further distinguishes it from other compounds in its class. It may modulate intracellular signaling pathways and stimulate growth hormone release from pituitary cells. Furthermore, it may affect the release of specific hormonal substances and appears to play a role in synaptic plasticity, memory consolidation, and cognitive processes. Hexarelin’s interactions with other hormonal substances, such as androgens and growth hormone-releasing hormone (GHRH), may influence its action. 

Disclaimer: The products mentioned are not intended for human or animal consumption. Research chemicals are intended solely for laboratory experimentation and/or in-vitro testing.  Bodily introduction of any sort is strictly prohibited by law.  All purchases are limited to licensed researchers and/or qualified professionals. All information shared in this article is for educational purposes only.

References

1. Khatib, N., Gaidhane, S., Gaidhane, A. M., Khatib, M., Simkhada, P., Gode, D., & Zahiruddin, Q. S. (2014). Ghrelin: ghrelin as a regulatory Peptide in growth hormone secretion. Journal of clinical and diagnostic research : JCDR, 8(8), MC13–MC17. https://doi.org/10.7860/JCDR/2014/9863.4767
2. Yin, Y., Li, Y., & Zhang, W. (2014). The growth hormone secretagogue receptor: its intracellular signaling and regulation. International journal of molecular sciences, 15(3), 4837–4855. https://doi.org/10.3390/ijms15034837
3. Frieboes, R. M., Antonijevic, I. A., Held, K., Murck, H., Pollmächer, T., Uhr, M., & Steiger, A. (2004). Hexarelin decreases slow-wave sleep and stimulates the secretion of GH, ACTH, cortisol and prolactin during sleep in healthy volunteers. Psychoneuroendocrinology, 29(7), 851–860. https://doi.org/10.1016/S0306-4530(03)00152-5
4. Imbimbo, B. P., Mant, T., Edwards, M., Amin, D., Dalton, N., Boutignon, F., Lenaerts, V., Wüthrich, P., & Deghenghi, R. (1994). Growth hormone-releasing activity of hexarelin in humans. A dose-response study. European journal of clinical pharmacology, 46(5), 421–425. https://doi.org/10.1007/BF00191904
5. Brywe, K. G., Leverin, A. L., Gustavsson, M., Mallard, C., Granata, R., Destefanis, S., Volante, M., Hagberg, H., Ghigo, E., & Isgaard, J. (2005). Growth hormone-releasing peptide hexarelin reduces neonatal brain injury and alters Akt/glycogen synthase kinase-3beta phosphorylation. Endocrinology, 146(11), 4665–4672. https://doi.org/10.1210/en.2005-0389
6. Loche, S., Cambiaso, P., Carta, D., Setzu, S., Imbimbo, B. P., Borrelli, P., Pintor, C., & Cappa, M. (1995). The growth hormone-releasing activity of hexarelin, a new synthetic hexapeptide, in short normal and obese children and in hypopituitary subjects. The Journal of clinical endocrinology and metabolism, 80(2), 674–678. https://doi.org/10.1210/jcem.80.2.7852535
7. Loche, S., Colao, A., Cappa, M., Bellone, J., Aimaretti, G., Farello, G., Faedda, A., Lombardi, G., Deghenghi, R., & Ghigo, E. (1997). The growth hormone response to hexarelin in children: reproducibility and effect of sex steroids. The Journal of clinical endocrinology and metabolism, 82(3), 861–864. https://doi.org/10.1210/jcem.82.3.3795
8. Arvat, E., Di Vito, L., Gianotti, L., Ramunni, J., Boghen, M. F., Deghenghi, R., Camanni, F., & Ghigo, E. (1997). Mechanisms underlying the negative growth hormone (GH) autofeedback on the GH-releasing effect of hexarelin in man. Metabolism: clinical and experimental, 46(1), 83–88. https://doi.org/10.1016/s0026-0495(97)90173-6
9. Massoud, A. F., Hindmarsh, P. C., & Brook, C. G. (1996). Hexarelin-induced growth hormone, cortisol, and prolactin release: a dose-response study. The Journal of clinical endocrinology and metabolism, 81(12), 4338–4341. https://doi.org/10.1210/jcem.81.12.8954038
10. Arvat, E., Gianotti, L., Di Vito, L., Imbimbo, B. P., Lenaerts, V., Deghenghi, R., Camanni, F., & Ghigo, E. (1995). Modulation of growth hormone-releasing activity of hexarelin in man. Neuroendocrinology, 61(1), 51–56. https://doi.org/10.1159/000126827

CJC-1295 belongs to a class of molecules known as growth hormone-releasing hormone (GHRH) agonists. It is a tetrasubstituted version of GHRH 1-29, representing the shortest functional sequence of GHRH. GHRH 1-29 consists of the first 29 amino acids of the native GHRH peptide and may potentially stimulate growth hormone production in pituitary gland cells. CJC-1295 is also modified by adding a drug affinity complex (DAC) component that may bind to plasma proteins. More specifically, the DAC component in CJC-1295 refers to the attachment of the N-epsilon-3-maleimidopropionamide derivative of lysine at the C terminus. By combining the tetrasubstituted amino acid sequence and the DAC component, CJC-1295 appears to exhibit improved pharmacokinetics while having a similar affinity to the GHRH receptors in the pituitary gland as native GHRH. More specifically, researchers comment that when the peptide was “selected for further pharmacokinetic evaluation, where it was found to be present in plasma beyond 72 h.”^[1] 

Ipamorelin is a synthetic pentapeptide that is considered to bind to another receptor found in pituitary gland cells, called growth hormone secretagogue receptor (GHS-R1a). These receptors are also found in the hypothalamus. Furthermore, GHS-R1a are also known as the ghrelin receptors, as ghrelin appears to be their main natural ligand. GHRP-2, or Growth Hormone Releasing Peptide 2, is a synthetic peptide composed of six amino acids. It also appears to bind to the ghrelin (GHS-R1a) receptors. By activating them, both Ipamorelin & GHRP-2 appear to stimulate the production of growth hormones in pituitary cells.

CJC-1295 & Ipamorelin & GHRP-2 and the GHRH Receptor

CJC-1295 & Ipamorelin & GHRP-2 may interact with various receptors found in the cells of the pituitary gland, such as the GHRH receptor. More specifically, the GHRH receptor is likely the primary target of CJC-1295. 

When the peptide potentially interacts with the growth hormone-releasing hormone GHRH receptor, it appears to bind with specific binding sites on the receptor protein, which may lead to conformational changes in the receptor structure. This binding event may initiate a cascade of molecular events that appear to activate signal transduction pathways within the target cells. 

The apparent conformational changes induced by CJC-1295 binding facilitate the potential activation of G-proteins, which are intracellular signaling proteins that may act as molecular switches. These G-proteins appear to be associated with the intracellular side of the GHRH receptor.^[2] Activated G-proteins may stimulate the production of second messengers like cyclic adenosine monophosphate (cAMP) or inositol trisphosphate (IP3), which may serve as secondary signaling molecules, propagating the signal further into the cell.^[3]

Second messengers such as cAMP may also activate protein kinases, which appear to be enzymes responsible for phosphorylating specific target proteins. Protein kinases may play a role in regulating various cellular processes. Activation of protein kinases might lead to the phosphorylation of transcription factors, which are proteins potentially involved in controlling gene expression. Once phosphorylated, these transcription factors may enter the nucleus and potentially modulate the transcription of specific genes associated with growth hormone synthesis and secretion. Ultimately, the molecular events triggered by CJC-1295 binding may result in the fusion of secretory vesicles containing growth hormone with the plasma membrane. This fusion enables the potential release of growth hormone outside the pituitary cells, where it may exert biological action.^[4]

CJC-1295 & Ipamorelin & GHRP-2 and the GHS-R1a

The GHS-R1a receptors are found in the pituitary gland and the hypothalamus and appear to be the main targets of Ipamorelin & GHRP-2. To understand their molecular mechanisms of interaction with GHS-R1a, it’s important to delve into the structure and function of both the receptor and the peptides. 

GHS-R1a is a G-protein coupled receptor (GPCR) that belongs to the class A rhodopsin-like family of receptors. It appears to play a potential role in regulating growth hormone release by pituitary cells into the extracellular environment.^[5] Scientists comment, “since its discovery, hundreds of studies have shown the importance of this receptor and its endogenous ligand, ghrelin, in metabolism, neurotransmission, and behavior.” The receptor consists of seven transmembrane domains, an extracellular N-terminus, and an intracellular C-terminus. The extracellular N-terminus of GHS-R1a may have the potential for ligand binding to agonists such as Ipamorelin & GHRP-2, while the intracellular C-terminus interacts with G-proteins to initiate signaling pathways.^[6]

Both Ipamorelin and GHRP-2 may act as agonists for GHS-R1a, meaning they potentially bind to the receptor and activate its signaling pathway. These peptides have a specific sequence of amino acids that allows them to potentially interact with GHS-R1a. The N-terminus of GHS-R1a contains binding sites that appear to recognize specific amino acid sequences in Ipamorelin and GHRP-2. When these peptides come into contact with the receptor, they appear to bind to these sites through non-covalent interactions such as hydrogen bonds, electrostatic interactions, and van der Waals forces. Upon Ipamorelin or GHRP-2 potentially binding to GHS-R1a, there appears to be a conformational change in the receptor. This change potentially leads to activating intracellular signaling pathways, primarily involving the G-proteins. GHS-R1a may interact with G-proteins, specifically the Gαq/11 subunit.^[7]

Activation of Gαq/11 triggers the release of a signaling molecule called GTP (guanosine triphosphate) from GDP (guanosine diphosphate) bound to Gαq/11. The GTP-bound Gαq/11 subunit dissociates from the receptor and may activate downstream signaling events. Furthermore, the dissociation of Gαq/11 from GHS-R1a may initiate a series of intracellular signaling cascades. 

One of the primary signaling pathways potentially activated by GHS-R1a involves the enzyme phospholipase C (PLC). Gαq/11 binds to PLC, which in turn may cleave a phospholipid called phosphatidylinositol 4,5-bisphosphate (PIP2) into two secondary messengers: inositol trisphosphate (IP3) and diacylglycerol (DAG).^[8] IP3 appears to bind to receptors on the endoplasmic reticulum, causing the release of calcium ions (Ca2+) from intracellular stores. Furthermore, DAG may activate protein kinase C (PKC), phosphorylating downstream signaling molecules, further amplifying the signaling cascade. These signaling events potentially lead to the activation of protein kinases, transcription factors, and other regulatory proteins involved in the growth hormone release by pituitary cells into the extracellular environment.

Conclusion

In conclusion, CJC-1295 & Ipamorelin & GHRP-2 may interact with receptors in the central nervous system, particularly in the pituitary gland cells and hypothalamus. These peptides are hypothesized to have neuroendocrine actions, and their unique structures are directly linked to their secretagogue-like potential. CJC-1295 may bind to GHRH receptors in the pituitary gland, potentially leading to conformational changes and the activation of intracellular signaling pathways for growth hormone production. Ipamorelin and GHRP-2 may bind to GHS-R1a receptors, also known as ghrelin receptors which may initiate a cascade of molecular events involving G-proteins, second messengers, protein kinases, and transcription factors, potentially resulting in the release of growth hormone. 

Disclaimer: The products mentioned are not intended for human or animal consumption. Research chemicals are intended solely for laboratory experimentation and/or in-vitro testing. Bodily introduction of any sort is strictly prohibited by law. All purchases are limited to licensed researchers and/or qualified professionals. All information shared in this article is for educational purposes only.

References

1. Jetté, L., Léger, R., Thibaudeau, K., Benquet, C., Robitaille, M., Pellerin, I., Paradis, V., van Wyk, P., Pham, K., & Bridon, D. P. (2005). Human growth hormone-releasing factor (hGRF)1-29-albumin bioconjugates activate the GRF receptor on the anterior pituitary in rats: identification of CJC-1295 as a long-lasting GRF analog. Endocrinology, 146(7), 3052–3058. https://doi.org/10.1210/en.2004-1286
2. Martin, B., Lopez de Maturana, R., Brenneman, R., Walent, T., Mattson, M. P., & Maudsley, S. (2005). Class II G protein-coupled receptors and their ligands in neuronal function and protection. Neuromolecular medicine, 7(1-2), 3–36. https://doi.org/10.1385/nmm:7:1-2:003
3. Newton, A. C., Bootman, M. D., & Scott, J. D. (2016). Second Messengers. Cold Spring Harbor perspectives in biology, 8(8), a005926. https://doi.org/10.1101/cshperspect.a005926
4. Ionescu, M., & Frohman, L. A. (2006). Pulsatile secretion of growth hormone (GH) persists during continuous stimulation by CJC-1295, a long-acting GH-releasing hormone analog. The Journal of clinical endocrinology and metabolism, 91(12), 4792–4797. https://doi.org/10.1210/jc.2006-1702
5. Albarrán-Zeckler, R. G., & Smith, R. G. (2013). The ghrelin receptors (GHS-R1a and GHS-R1b). Endocrine development, 25, 5–15. https://doi.org/10.1159/000346042
6. Childs, M. D., & Luyt, L. G. (2020). A Decade’s Progress in the Development of Molecular Imaging Agents Targeting the Growth Hormone Secretagogue Receptor. Molecular imaging, 19, 1536012120952623. https://doi.org/10.1177/1536012120952623
7. Yin, Y., Li, Y., & Zhang, W. (2014). The growth hormone secretagogue receptor: its intracellular signaling and regulation. International journal of molecular sciences, 15(3), 4837–4855. https://doi.org/10.3390/ijms15034837
8. Bill, C. A., & Vines, C. M. (2020). Phospholipase C. Advances in experimental medicine and biology, 1131, 215–242. https://doi.org/10.1007/978-3-030-12457-1_9