Effect of Lactobacillus Reuteri on Heat S tress-inducedEffect on HSP۷۰-۲a and HSP۹۰ Heat Shock ProteinsExpression in Rat Tes ticles

Background: Heat s tress has been shown to repress spermatogenesisand spermiogenesis processes, resulting in fertilityproblems in male subjects. The probiotics are shown to promotethe spermatogenesis development, endocrine potential of thetes ticles, and semen quality by using animal models. Heat shockproteins are key responders proteins in maintaining the hemostasis of the molecular mechanisms in the germ and somaticcells of tes ticular tissue in heat s tress circums tances. Moreover,these proteins are known to protect sperm DNA integrity byregulating chromatin-his tone exchange process. Therefore, thecurrent s tudy was performed to examine the effect of lactobacillusreuteri probiotic (LRP) on heat shock proteins Hsp۷۰-۲aand Hsp۹۰ expression levels in tes ticular tissue and to explorechromatin condensation and DNA integrity of sperm cells afterheat s tress condition.Materials and Methods: For this purpose, ۳۰ mature maleWis tar rats were divided into control (n=۶) and heat s tress-induced(n=۲۴) groups. Then, the heat s tress group subdivided into ۳۷°C and ۴۰°C sole (n=۶/ each group) as well as lactobacillusreuteri probiotic-treated (۱mg/rat LRP+۳۷°C and ۱mg/rat LRP+۴۰°C, n=۶/ each group) groups. The heat s tresswas induced by using water bath (۲۰ min/day, for ۴۸ days)and the LRP was adminis trated orally for ۴۸ days. Thereafter,the animals were euthanized, tes ticles were dissected out andthe Hsp۷۰-۲a+ and hsp۹۰+ immunoreactivities in spermatidswere analyzed. Moreover, the percentage of sperms with normalchromatin condensation and DNA integrity were analyzed.One-way ANOVA and bonferroni pos t-hoc tes ts were used fors tatis tical analyses.Results: Observations revealed that as the temperature increased,the mean dis tribution of Hsp۷۰-۲a+ and Hsp۹۰+spermatids were decreased. However, the LRP-treated groupsshowed a significant (P<۰.۰۵) increment in Hsp۷۰-۲a+ andHsp۹۰+ spermatids per seminiferous tubules. Finally, the percentagesof sperms with normal chromatin condensation andDNA integrity were increased in the LRP-treated groups. thissituation was more evident in ۳۷°C+LRP group.Conclusion: Heat s tress is able to detrimentally affect the chromatin-his tone exchange process by suppressing Hsp۷۰-۲a andHsp۹۰ expression at spermatids, which in turn is able to resultin severe DNA damage.

کلیدواژه ها:

DNA Damage ، Heat Shock Proteins ، Heat S tress ، Probiotic