Repair and Recovery Research

Peptides for Tendon Repair Research

Tendon injuries are incredibly common, not just among athletes, but in the general population. Commonly injured tendons include the Achilles and biceps tendon as well as tendons of the hands and feet. Unlike most illnesses and injuries, however, tendon injuries are more common among the young than the old. This is counterintuitive, especially given that the cause of these injuries is cumulative degeneration followed by sudden excess loading. Few of tendon injuries are caused by systemic disease or a genetic disorder.The incidence of tendon-related injuries is on the rise, increasing almost 140% between 2012 and 2016[1]. The increase is attributed to greater amateur athletic participation, but also has roots in high rates of on-the-job injuries. For these reasons, and many others, peptides for tendon repair research have become a hot topic. Here is a look at what the state of the art is in the field of peptides for tendon repair research.

How Do Tendons Heal?

Tendons connect muscle to bone and transfer all the energy from a muscle contraction to the bones that provide structure and support. Unfortunately, tendons can be cut, bruised, sprained, or ruptured in a variety of ways. Tendon ruptures are serious and can take anywhere from four to eighteen months to heal and almost always require surgery. Even tendonitis, which is just inflammation due to minor damage, can take upwards of four months to heal.

Unfortunately, injured tendons are at higher risk of re-injury, generally because the healing process is not as orderly as when a tendon is originally formed. Tendons are not designed to regenerate, but rather are meant to last a lifetime without much change. As such, they do not possess the kind of regenerative properties (e.g., abundant stem cells) that tissues like the GI tract or skin do. What is worse, the rate at which a tendon can heal, even if the healing is limited, is almost always outpaced by the rate at which we can cause injury to it. In other words, tendon injury tends to accumulate and the more active you are, the more likely you are to experience a large-scale tendon failure.

Under the healing process, tendons first become inflamed, an immune response that causes pain and limits mobility. This stage, however, is slow to resolve because of the tendon’s poor blood supply. Eventually, however, healing gives way to the repair phase in which cells like fibroblasts proliferate and start replacing damaged tissue. This stage then gives way to remodeling, which is carried out by stem cells and various other cells. Once again, the relative dearth of nutrient supply to the tendon limits the effectiveness of these stages and accounts for the very slow rate at which tendons heal.

What is Thymosin Beta-4?

The beta-thymosins (b-thymosins) comprise a family of structurally related, highly conserved amino acid sequences in species ranging from mammals to echinoderms. Of the 16 known family members, thymosin β4 (Tb4), thymosin β10 (Tb10), and thymosin β15 (Tb15) are found in man.

Thymosin beta-4 (TB4) is a 43 amino acid, 5kDa polypeptide that is an important mediator of cell proliferation, migration, and differentiation. TB4 is the most abundant member of the β- thymosin family in mammalian tissue and is regarded as the main G-actin sequestering peptide. It is found in all tissues and cell types except red blood cells. Thymosin beta-4 is angiogenic and can promote endothelial cell migration and adhesion, and angiogenesis. TB4 also accelerates wound healing and reduces inflammation and scarring when applied in dermal wound-healing assays.

Beta thymosins bind and sequester monomeric actin, thus preventing actin polymerization and formation of filamentous actin. Actin is a vital component of cell structure and movement. Actin is involved in many important non-muscle cellular processes, including cell locomotion, chemotaxis, phagocytosis, and cytokinesis. Of the thousands of proteins present in cells, actin makes up to 10% of the total proteins in a cell, representing a major role in the genetic makeup of the cell.

Animal studies of disease and repair when using thymosin beta-4, the major actin-sequestering molecule in mammalian cells, have provided a base for the ongoing multicenter clinical trials for wound healing, including dermal, corneal, and cardiac. TB4 has multiple biological activities, which include down-regulation of inflammatory chemokines and cytokines, and promotion of cell migration, blood vessel formation, cell survival, and stem cell maturation.

Thymosin beta-4 also inhibits inflammation, microbial growth, scar formation (by reducing the level of myofibroblasts), and apoptosis, and protects cells from cytotoxic damage, including glutamate neuronal toxicity. In addition, it binds to G-actin, blocks actin polymerization, and is released with factor X by platelets. These activities contribute to the multiple wound healing properties that have been reported in animal and human studies.

BPC 157 Arginate vs BPC 157 Acetate

Another way to evaluate the quality of a BPC 157 source is to look at whether the seller understands the difference between the arginate and acetate versions of the peptide. BPC 157 acetate is a slightly modified version of the natural peptide that provides for increased shelf-life and better resistance to the extremes of shipping environments. BPC 157 acetate is commonly used for subcutaneous injection as it is degraded in the GI tract to such an extent that nearly 98% of it is gone after just a short time in gastric acid.For researchers interested in understanding the effects of oral administration of BPC 157, then the arginate salt is preferred. BPC 157 arginate retains the superior shipping and storage properties of BPC 157 acetate, but is also stable in gastric acid for extended periods. Research shows that just 10% of BPC 157 arginate is degraded after 5 hours in gastric acid.BPC 157 arginate is sometimes referred to as “stable BPC 157.” This is a correct usage of the term stable, but it is important for anyone looking to buy BPC 157 that they specify whether the seller is referring to BPC 157 arginate or acetate as the two peptides are both “stable” depending on context.

What Is BPC 157?

If you are looking to purchase BPC 157, you likely already know what the peptide is and the research that has been done on it. Still, it is important to cover this topic broadly so that you can evaluate whether the BPC 157 source you are considering buying BPC 157 from is reliable or not.

BPC 157 is a synthetically produced peptide based off of the naturally occurring body protection compound (BPC) protein that was isolated from human gastric contents. This short peptide has been shown to have both anti-inflammatory and wound healing effects not just in the gastrointestinal system, but in musculoskeletal and neurological tissue as well. BPC 157 also promotes the growth of blood vessels and is thought to help maintain homeostasis.

Research on BPC 157 has focused primarily on its wound healing properties. It has undergone phase 1 clinical trials and has been investigated as a potential treatment for tendon injury, inflammatory bowel disease, and accelerating the rate of fistula healing.

Ac-SDKP is a Peptide Fragment of Thymosin Beta 4 (TB-500)

“Tβ4 is a naturally occurring peptide consisting of 43 base pairs of amino acids and generates the N-terminal tetrapeptide AcSDKP.” (14)

Peptide Ac-SDKP was isolated from the whole Thymosin Beta 4 Peptide Sequence.

Ac-SDKP Reduced Kidney Fibrosis.

“Treatment of cultured cells with ACEi alone or in combination with AcSDKP prevented the downregulated expression of miR-29s and miR-let-7s induced by TGFβ stimulation. Interestingly, ACEi also restored miR-29 and miR-let-7 family cross-talk in endothelial cells, an effect that is shared by AcSDKP suggesting that AcSDKP may be partially involved in the anti-mesenchymal action of ACEi. The results of the present study promise to advance our understanding of how ACEi regulates antifibrotic microRNAs crosstalk and DPP-4 associated-fibrogenic processes which is a critical event in the development of diabetic kidney disease.” (14)

How Does BPC 157 Work?

BPC 157 is a derivative of a natural protein called body protection compound (BPC). BPC was first isolated from the digestive system where it plays an important role in protecting the stomach lining from stomach acid. Research has since revealed that the healing properties of BPC 157 extend well beyond the gut. The peptide has been shown to boost wound healing in a variety of tissues, increase the rate of blood vessel growth, improve blood clotting, and enhance the immune system.To understand how BPC 157 can have such wide-ranging effects, it is necessary to start at the most basic level of its activity to see how its properties build upon one another to create an excellent healing peptide.

How Does BPC 157 Work in Blood Vessels?

Research shows that BPC 157 works in two different ways in blood vessels. First, it helps blood vessels to relax so that blood flows more easily through them. It does this by increasing concentrations of a natural compound called nitric oxide. Nitric oxide is critical to not just maintaining blood pressure, but to maintaining the health of the endothelial cells that line blood vessels. (11)