Thymulin (also known as Thymic Factor or under its old name Facteur Thymique Serique) is a nonapeptide produced by two distinct epithelial populations in the thymus first described by Bach in 1977. It requires zinc for biological activity.
The hormon is believed to be involved in T-cell differentiation and enhancement of T and NK cell actions. Besides this rather paracrine or auto-organic effects on the thymus dependent immune system, Thymulin seems to have neuroendocrine effects as well. There exist bidirectional interactions between thymic epithelium and the hypothalamus-pituitary axis (for example, thymulin follows a circadian rhythm and physiologically elevated ACTH levels correlate positively with thymulin plasma levels and vice versa).
A recent focus has been on the role of thymulin as an effector on proinflammatory mediators/cytokines. A peptide analogue of thymulin (PAT) has been found to have analgesic effects in higher concentrations and particularly neuroprotective anti-inflammatory effects in the CNS.
Astrocytes seem to be the target for thymulin for this effect.
Researchers hopes to develop drugs thwarting inflammatory processes associated with neurodegenerative diseases and even rheumatism with the help of thymulin analoga.
- Bach J, Bardenne M, Pleau J, Rosa J (1977). "Biochemical characterisation of a serum thymic factor". Nature. 266 (5597): 55–7. PMID 300146.
- Hadley AJ, Rantle CM, Buckingham JC (1997). "Thymulin stimulates corticotrophin release and cyclic nucleotide formation in the rat anterior pituitary gland". Neuroimmunomodulation. 4 (2): 62–9. PMID 9483196.
- Dardenne M, Saade N, Safieh-Garabedian B (2006). "Role of thymulin or its analogue as a new analgesic molecule". Ann. N. Y. Acad. Sci. 1088: 153–63. doi:10.1196/annals.1366.006. PMID 17192563.
- Wade S, Bleiberg F, Mossé A; et al. (1985). "Thymulin (Zn-facteur thymique serique) activity in anorexia nervosa patients". Am. J. Clin. Nutr. 42 (2): 275–80. PMID 3927699.