What Is TB-500 (Thymosin Beta-4)?

Thymosin Beta 4, or TB-500, is a synthetic version of a naturally occurring 43-amino acid peptide present in nearly all human and animal cells studied.

A 2010 study in the Annals of the New York Academy of Sciences supported TB500’s potential for cardiac muscle repair following injury, eg, after myocardial infarction (heart attack).  Recognizing the limitations of stem cell therapy for this application, TB500 was found to inhibit myocardial cell death, stimulate blood vessel growth, and activate cardiac processes that encouraged the heart to heal following injury.  The investigation showed that TB500 may be the first agent which can actively recover injured cardiac muscle following heart attack.  This is further supported with prior mouse studies in 2004 showing cardiomyocyte migration, survival and repair of myocardial damage. 

Filamentous actin (F-actin, or actin) forms polymers that thicken sputum, adversely affecting cystic fibrosis patients.  TB500 was studied in a population of CF patients, showing a dose- and time-dependent decrease in cohesivity of sputum after administration of TB500 when combined with dornase alfa.  The combination therapy showed a 71% improvement in mucociliary transport of mucus, and a 44% improvement in cough transport of mucus. 

TB500 is known to stimulate myoblasts and myocytes (muscle generating cells).  Mitochondrial RNA levels of TB500 have been shown to increase following muscle injury, helping to regenerate muscle fibers and address inflammation in the injured location.  The data support muscle injury causing increased local production of TB500, promoting migration of incoming myoblasts to accelerate skeletal muscle regeneration.