What is Humanin peptide?
Humanin is a naturally occurring micropeptides that are unique in that they are encoded by mitochondrial DNA (mitochondria contain small amounts of DNA reserved exclusively for them). It acts as a cytoprotective protein and protects cells from the process of apoptosis (programmed cell death) by interfering with the normal operation of the Bcl2-related X protein (Bax). Studies show that humanin is important for protecting neurons, heart tissue, muscle cells, the retina of the eye, and the lining of blood vessels.
AKA: formyl humanin, HNGF6A protein
Molecular Formula: C119H204N34O32S2
Molecular Weight: 2687.3 g/mol
CAS Number: 330936-69-1
What Is a Micro-peptide?
Micropeptides are produced by a short open reading frame (sORF) and are not modified after production. Many sORFs have been identified in humans, measuring 100-150 amino acids in length. Their functions range from improving mRNA processing to assisting in repairing DNA damage and creating complex macro-proteins by interacting with other proteins. Humanin, one of the smallest micropeptides known to date, is only 24 amino acids long. It interacts with the Bcl2-related X protein (Bax) to regulate apoptosis and, if necessary, block Bax function and protect cells that would otherwise be destroyed.
Studies in rats have shown that micropeptides protect Alzheimer’s disease neurons and prevent cell death caused by the formation of beta-amyloid plaques. Studies show that peptides prevent the death of excitotoxic neurons in experiments with NMDA pulses. It is hoped that this function of humanin can delay or stop neurodegenerative diseases such as Alzheimer’s disease and other forms of dementia. Under normal circumstances, Bcl2 family proteins signal the release of proteins from mitochondrial membranes, activating caspases and coordinating the orderly destruction and recycling of cells. This process is practically useful in many situations, such as when a virus invades, where a small number of cells can be destroyed to prevent widespread tissue damage. Unfortunately, the process can become dysregulated in certain medical conditions, leading to widespread unsuppressed cell death. Humanin binds to the Bcl2-stimulating proteins Bid and tBid and blocks their function. This shuts down the apoptotic pathway at its origin.
Humanin Interfaces with IGF-1
A recent study from the University of Southern California found that humanin and insulin-like growth factor 1 (IGF1) and humanin reduces the circulating levels of IGF1 and IGF1 and affects humanin levels. Peptides are synergistic in many ways, working together to suppress apoptosis, increase insulin sensitivity, reduce inflammation, and protect against certain forms of heart disease.
A study by the Mayo Clinic, a major medical facility in the United States, shows that humanin is expressed on the walls of the human vascular system and interferes with the production of reactive oxygen species (free radicals) in response to LDL oxidation. It reduces active oxygen species in the vascular system by 50% and reduces apoptosis by 50%. Cardiology researchers have long sought blood markers that could be used to quantify how effectively mitochondria function in cardiovascular disease. It is an important measure of the patients’ health with heart disease and helps accurately estimate tissue ischemia and disease progression and determine when to intervene. According to a Russian study, the reduction is proportional to the severity of cardiovascular disease, so humanin levels may be a good marker in this situation.
Humanin Research and Retinal Disease
Retinal pigment epithelium (RPE) is the layer of the retina that covers and nourishes the cells that cause vision. It plays a role in the absorption and scattering of light, filtering blood components that reach the inside of the retina. It also, above all, establishes the nature of immune privilege inside the eye. RPE damage is found in age-related macular degeneration, diabetic retinopathy, and other common serious eye conditions. Current studies have shown that humanin is an important component of RPE and reduces oxidative stress in this tissue. Humanin supplementation in cell culture improves RPE function and increases tissue resistance to apoptosis. This may help scientists develop more effective treatment and prevention strategies for retinal disorders such as macular degeneration.
Bone loss is a serious condition that affects many people, especially women, with age. It is also the result of many medical conditions and is even caused by certain medical interventions. In the latter category, glucocorticoids used to treat severe inflammation (such as autoimmune inflammation) are the most notorious gamblers. They cause extreme bone loss when used at high doses or for long periods. Researchers in Sweden and South Korea have discovered that humanin can benefit bone in two different ways. First, micropeptides were found to prevent chondrocytes (cells that produce the collagen matrix in which bone is built) from dying without affecting the anti-inflammatory effects of glucocorticoids such as dexamethasone.
This effect increases bone and cartilage growth and helps offset some of the accelerated bone loss caused by glucocorticoids. At the same time as promoting chondrocyte development, humanin appears to reduce osteoclast formation. Osteoclasts are the cells that cause bone loss and remodeling. Overactivation of these cells is useful and important for normal physiologic function in pathological conditions, resulting in severe bone loss. By preventing osteoclast formation, humanin helps to reduce excessive bone remodeling and loss.