Title: Palmitoyl-protein thioesterase 1 (PPT1): an obesity-induced rat testicular marker of reduced fertility Liu Y, Zhao W, Gu G, Lu L, Feng J, Guo Q, Ding Z Ref: Mol Reprod Dev, 81:55, 2014 : PubMed
Male obesity may lead to declines in testosterone levels, reproductive hormonal profile, and semen quantity. To assess the effects of obesity on spermatogenesis, Sprague-Dawley rats fed a high-fat diet served as a model of induced obesity. The litter sizes for females mated to obese males were significantly lower as compared to females mated with normal-diet-fed controls. Their serum high-density lipoprotein, low-density lipoprotein, cholesterol, and estradiol levels increased in obese males, but testosterone and follicle-stimulating hormone levels decreased. Testicular morphology disruptions included Sertoli-cell atrophy, disrupted tight junctions, and mitochondrial degeneration in spermatogenic cells. To further investigate the molecular mechanisms leading to high-fat-diet-induced changes, we employed testicular proteomic analysis on rats fed both types of diet. Three spots were up-regulated in rats fed a high-fat diet whereas two others were downregulated. One of the upregulated spots was palmitoyl-protein thioesterase 1 (PPT1), a lipoprotein metabolizing related enzyme localized to Sertoli cells. In a Sertoli-cell line cultured in a high-fat supplemented medium, PPT1 abundance was accompanied by increases in the endocytic vesicle-associated protein, clathrin, and decreases in the tight junctional proteins, ZO-1 and occludin. In conclusion, declines in rat male fertility induced by a high-fat diet are associated with an altered testicular protein expression pattern as well as disruption of testicular Sertoli-cell and spermatogenic-cell morphology. PPT1 expression may provide a testicular marker of reduced fertility in obese males, as increases in its expression may be detrimental to Sertoli-cell function during spermatogenesis.
Liu Y, Zhao W, Gu G, Lu L, Feng J, Guo Q, Ding Z (2014) Palmitoyl-protein thioesterase 1 (PPT1): an obesity-induced rat testicular marker of reduced fertility Mol Reprod Dev81: 55-65
Liu Y, Zhao W, Gu G, Lu L, Feng J, Guo Q, Ding Z (2014) Mol Reprod Dev81: 55-65