Inflammation and oxidative stress in the aging testis

FRUNGIERI MB

Congreso; 12th International, 11th European and 32nd German Congress of Andrology; 2020

In order to investigate a potential relation between aging and inflammatory-oxidant processes in the male gonad, we used well-established mouse models with alterations of the somatotropic signaling and longevity. We described that the testes of short-lived mice with accelerated aging (growth hormone-transgenic mice) show a significant increase in cyclooxygenase 2 expression, PGD2 production, lipid peroxidation, antioxidant enzymes expression, and the number of local macrophages. In contrast, these parameters showed a reduction in testes of long-lived mice with delayed aging (growth hormone releasing hormone-knockout mice and Ames dwarf mice). Our data provide novel evidences indicating that longevity confers anti-inflammatory and anti-oxidant capacities to the adult testis. Oppositely, short-lived mice with accelerated aging suffer testicular inflammatory and oxidative processes. We further verified these results using a physiological model of aging without mutations in the GH/IGF-1 pathway. Raised levels of inflammatory and oxidative stress markers were detected in testes of naturally aged Syrian hamsters. This species is a seasonal breeder in which the progressive increase in testicular inflammation and lipid peroxidation with age is inversely associated with the gonadal levels of melatonin. Moreover, when aged hamsters were transferred from a long day to a short day photoperiod for 16 weeks, testicular melatonin concentration increased while local inflammatory processes and oxidative stress were clearly reduced. The latter allows us to speculate about anti-inflammatory and antioxidant actions of this neurohormone in the testis.Interestingly, in testes of young and middle-age adult men with idiopathic infertility, we described similar findings to those observed in the testis of aged rodents. In view of these observations, it is possible to conclude that there is a clear parallelism between the changes taking place in the aged-testis and the alterations that occur in gonads of young adult infertile men.