Introduction: Extracellular matrix (ECM) has both structural and regulatory roles in tissues and influences the activity of local growth factors. In testis, ECM plays an integral role in the differentiation of germ cells and the function of support cells. It is becoming clear that sex steroids influence ECM and growth factors. In swine, suppression of aromatase activity resulted in an estrogen receptor-mediated increase in Sertoli cells (Berger et al. 2013), with significantly reduced WISP2 mRNA expression up to 5 weeks of age.
Materials and methods: To determine the action of estrogens on ECM in porcine testes, male pigs were treated weekly for 16 weeks with vehicle or an enzymatic inhibitor of estrogen synthesis (letrozole, 0.1 mg/kg body weight) and killed at 6, 11, 20, or 40 weeks of age and testes collected for histology. Image analysis of silver-stained sections was performed to determine the proportion of collagen, and other ECM components were evaluated by immunohistochemistry.
Results: Although there were no differences attributable to treatment, there was a significant reduction in the proportion of collagen with age: from 24.8±2.8% at 6 weeks to 16.1±4.1% at weeks of age (P<0.001). Collagen types I and III, and versican, fibronectin and fibrillin 2 all decreased in expression with age. Collagen types I and III were localized to the peritubular region, fibronectin was localized to the interstitial space and versican and fibrillin 2 localised to the perivascular connective tissue.
Conclusion: Significant changes in ECM occur during testis development with age, and may be independent of estradiol synthesis during the developmental window examined.
02 - 04 Sep 2014
World Congress of Reproductive Biology