Abstract
In the course of aging, the steroidogenic function of the testes weakens and their gonadotropin sensitivity decreases. However, the underlying mechanisms are poorly understood. The goal of this work was to study the stimulating effects of human chorionic gonadotropin (hCG) and TP03, a low molecular weight agonist of luteinizing hormone (LH)/hCG receptor, on testosterone production and the expression of steroidogenic proteins in young (3-month-old) and aging (15-month-old) male rats and to investigate the activity of the adenylyl cyclase system in the membranes isolated from the rat testes. Treatment with hCG (100 IU/rat/day) and TP03 (15 mg/kg/day) was carried out for 3 days. In the testes of aging rats, adenylyl cyclase stimulation by gonadotropin and guanine nucleotide was decreased, indicating a weakening of the coupling of LH/hCG receptor and Gs protein, the main components of the adenylyl cyclase system regulating the steroidogenesis. In elderly rats, the blood testosterone levels and the expression of the Star, Cyp11a1, and Cyp17a1 genes, which encode the StAR protein and the steroidogenic enzymes cytochromes P450scc and P450-17α in the testes, were decreased. The stimulating effect of both hCG and TP03 on testosterone production diminished with age, although their effects on LH/hCG receptor are mediated by different mechanisms. In both young and aging rats, hCG treatment upregulated the expression of the genes encoding StAR, P450scc and dehydrogenase 3β-HSD; at the same time, Hsd17B expression in aging rats increased, and the expression of the genes encoding P450-17α and 17β-HSD decreased in young rats. In young rats, TP03 treatment upregulated Star and Cyp17a1 expression, and it increased Star and Hsd17B expression in aging rats. Thus, in the testes of aging rats, the coupling between the LH/hCG receptor and Gs protein and LH/hCG receptor sensitivity to agonists were weakened, which led to a decrease in hCG- and TP03-induced testosterone production and altered the basal and LH/hCG receptor agonist–stimulated expression levels of some steroidogenic protein genes.
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REFERENCES
Bakhtyukov, A.A., Sokolova, T.V., Dar’in, D.V., et al., The stimulating effect of a low-molecular agonist of the luteinizing hormone receptor and chorionic gonadotropin on steroidogenesis in rat Leydig cells, Ross. Fiziol. Zh. im. I.M. Sechenova, 2017, vol. 103, no. 10, pp. 1181–1192.
Bakhtyukov, A.A. and Shpakov, A.O., Molecular mechanisms of steroidogenesis regulation in Leydig cells, Tsitologiya, 2016, vol. 58, no. 9, pp. 666–678.
Derkach, K.V., Bakhtyukov, A.A., Shpakov, A.A., Dar’in, D.V., and Shpakov, A.O., Specificity of heterotrimeric G protein regulation by human chorionic gonadotropin and low-molecular agonist of luteinizing hormone receptor, Cell Tissue Biol., 2017, vol. 11, no. 6, pp. 475–482.
Derkach, K.V., Dar’in, D.V., Bakhtyukov, A.A., Lobanov, P.S., and Shpakov, A.O., In vitro and in vivo studies of functional activity of new low molecular weight agonists of the luteinizing hormone receptor, Biochemistry (Moscow) Suppl. Ser. A: Membr. Cell Biol., 2016, vol. 10, no. 4, pp. 294–300.
Derkach, K.V., Dar’in, D.V., Lobanov, P.S., and Shpakov, A.O., Intratesticular, intraperitoneal, and oral administration of thienopyrimidine derivatives increases the testosterone level in male rats, Dokl. Biol. Sci., 2014, vol. 459, no. 1, pp. 326–329.
Shpakov, A.O., Structural and functional organization of polypeptide hormone receptors containing LRR repeats and their interaction with heterotrimeric G proteins, Tsitologiya, 2009, vol. 51, no. 8, pp. 638–649.
Shpakov, A.O., The action mechanisms of low-molecular agonists of thyrotropic and luteinizing hormone receptors, Tsitologiya, 2015, vol. 57, no. 3, pp. 167–176.
Shpakov, A.O., Derkach, K.V., Dar’in, D.V., and Lobanov, P.S., Activation of adenylyl cyclase by thienopyrimidine derivatives in rat testes and ovaries, Cell Tissue Biol., 2014, vol. 8, no. 5, pp. 400–406.
Aghazadeh, Y., Zirkin, B.R., and Papadopoulos, V., Pharmacological regulation of the cholesterol transport machinery in steroidogenic cells of the testis, Vitam. Horm. (London), 2015, vol. 98, pp. 189–227. https://doi.org/10.1016/bs.vh.2014.12.006
Chen, H., Cangello, D., Benson, S., et al., Age related increase in mitochondrial superoxide generation in the testosterone producing cells of Brown Norway rat testes: relationship to reduced steroidogenic function?, Exp. Gerontol., 2001, vol. 36, pp. 1361–1373.
Chen, H., Hardy, M.P., and Zirkin, B.R., Age-related decreases in Leydig cell testosterone production are not restored by exposure to LH in vitro, Endocrinology, 2002, vol. 143, no. 5, pp. 1637–1642.
Chen, H., Liu, J., Luo, L., and Zirkin, B.R., Dibutyryl cyclic adenosine monophosphate restores the ability of aged Leydig cells to produce testosterone at the high levels characteristic of young cells, Endocrinology, 2004, vol. 145, no. 10, pp. 4441–4446.
Derkach, K.V., Bondareva, V.M., Chistyakova, O.V., et al., The effect of long-term intranasal serotonin treatment on metabolic parameters and hormonal signaling in rats with high-fat diet/lowdose streptozotocin-induced type 2 diabetes, Int. J. Endocrinol., 2015, vol. 2015, p. 245 459. https://doi.org/10.1155/2015/245459
Harman, S.M., Metter, E.J., Tobin, J.D., et al., Longitudinal effects of aging on serum total and free testosterone levels in healthy men, J. Clin. Endocrinol. Metab., 2001, vol. 86, no. 2, pp. 724–731.
Luo, L., Chen, H., and Zirkin, B.R., Temporal relationship among testosterone production, steroidogenic acute regulatory protein (StAR), and P450 side-chain cleavage enzymes (P450scc) during Leydig cells aging, J. Androl., 2005, vol. 26, no. 1, pp. 25–31.
Midzak, A.S., Chen, H., Paoadopoulus, V., and Zirkin, B.R., Leydig cell aging and the mechanisms of reduce testosterone synthesis, Mol. Cell. Endocrinol., 2009, vol. 299, no. 1, pp. 23–31.
Newton, C.L., Whay, A.M., McArdle, C.A., et al., Rescue of expression and signaling of human luteinizing hormone G protein-coupled receptor mutants with an allosterically binding smallmolecule agonist, Proc. Natl. Acad. Sci. U.S.A., 2011, vol. 108, no. 17, pp. 7172–7176.
Payne, A.H. and Hales, D.B., Overview of steroidogenic enzymes in the pathway from cholesterol to active steroid hormones, Endocrinol. Rev., 2004, vol. 25, no. 6, pp. 947–970.
Puett, D., Angelova, K., Da Costa, M.R., et al., The luteinizing hormone receptor: insights into structure-function relationships and hormone-receptor-mediated changes in gene expression in ovarian cancer cells, Mol. Cell. Endocrinol., 2010, vol. 329, nos. 1–2, pp. 47–55.
Riccetti, L., De Pascali, F., Gilioli, L., et al., Human LH and hCG stimulate differently the early signalling pathways but result in equal testosterone synthesis in mouse Leydig cells in vitro, Reprod. Biol. Endocrinol., 2017, vol. 15, no. 1, p. 2. https://doi.org/10.1186/s12958-016-0224-3
Sokanovic, S.J., Capo, I., Medar, M.M., et al., Long-term inhibition of PDE5 ameliorates aging-induced changes in rat testis, Exp. Gerontol., 2018, vol. 108, pp. 139–148. https://doi.org/10.1016/j.exger.2018.04.007
Sokanovic, S.J., Janjic, M.M., Stojkov, N.J., et al., Age related changes of cAMP and MAPK signaling in Leydig cells of Wistar rats, Exp. Gerontol., 2014, vol. 58, pp. 19–29. https://doi.org/10.1016/j.exger.2014.07.004
Song, C.H., Gong, E.Y., Park, J., and Lee, K., Testicular steroidogenesis is locally regulated by androgen via suppression of Nur77, Biochem. Biophys. Res. Commun., 2012, vol. 422, no. 2, pp. 327–332. https://doi.org/10.1016/j.bbrc.2012.04.161
van de Lagemaat, R., Raafs, B. C., van Koppen, C., et al., Prevention of the onset of ovarian hyperstimulation syndrome (OHSS) in the rat after ovulation induction with a low molecular weight agonist of the LH receptor compared with hCG and rec-LH, Endocrinology, 2011, vol. 152, no. 11, pp. 4350–4357.
van Koppen, C.J., Zaman, G.J., Timmers, C.M., et al., A signaling-selective, nanomolar potent allosteric low molecular weight agonist for the human luteinizing hormone receptor, Naunyn-Schmiedeberg’s Arch. Pharmacol., 2008, vol. 378, no. 5, pp. 503–514.
Wang, Y., Chen, F., Ye, L., et al., Steroidogenesis in Leydig cells: effects of aging and environmental factors, Reproduction, 2017, vol. 154, no. 4, pp. R111–R122. https://doi.org/10.1530/REP-17-0064
Zirkin, B.R., Santulli, R., Strandberg, J.D., et al., Testicular steroidogenesis in the aging brown Norway rat, J. Androl., 1993, vol. 14, no. 2, pp. 118–123.
ACKNOWLEDGMENTS
NMR, mass spectrometry, and radioisotopic studies were performed on the equipment of the resource centers of the St. Petersburg University Science Park: Magnetic Resonance-Based Methods and Methods of Composition Analysis, as well as the Collective Use Center of the Sechenov Institute.
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This work was supported by the Russian Foundation for Basic Research (project no. 16-04-00126) and partially supported by State Assignment AAAA-A18-118012290427-7.
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Statement on the welfare of animals. All procedures were performed in agreement with the requirements of the Ethical Committee of the Sechenov Institute, European Communities Council Directive 1986 (86/609/EEC), and the Guide for the Care and Use of Laboratory Animals.
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Translated by D. Timchenko
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Bakhtyukov, A.A., Derkach, K.V., Dar’in, D.V. et al. Decrease in the Basal and Luteinizing Hormone Receptor Agonist–Stimulated Testosterone Production in Aging Male Rats. Adv Gerontol 9, 179–185 (2019). https://doi.org/10.1134/S2079057019020036
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DOI: https://doi.org/10.1134/S2079057019020036