Effects of aging on the male reproductive system

Güneş, Sezgin; Hekim, Neslihan; Arslan, Mehmet Alper; Aşçı, Ramazan

doi:10.1007/s10815-016-0663-y

Cited by 195 publications

(150 citation statements)

References 146 publications

(162 reference statements)

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“…When either starved or amputated, the hermaphroditic sexual organs are resorbed likely due to loss of nhr-1 signaling, only to be restored once food is available, the animals reach an appropriate size (Newmark and Sanchez Alvarado, 2002), and lipid metabolism is once again activated to maintain the RS. In both men and women, the reduction of hormone synthesis and gametes are usually the earliest signs of aging (Gunes et al, 2016; Makabe et al, 1998), with other organs such as the liver and brain decreasing in volume in the elderly (Hedman et al, 2012; Makabe et al, 1998; Motta et al, 2002; Paniagua et al, 1991; Tajiri and Shimizu, 2013). Moreover, the ectopic lipid accumulation observed in normal aged people and premature menopause patients (Knauff et al, 2008; Toth and Tchernof, 2000), is only observed in planarians after the loss of either nhr-1 or acs-1 .…”

Section: Discussionmentioning

confidence: 99%

A nuclear hormone receptor and lipid metabolism axis are required for the maintenance and regeneration of reproductive organs

Zhang

Guo

Guerrero‐Hernández

et al. 2018

Preprint

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Understanding how stem cells and their progeny maintain and regenerate reproductive organs is of fundamental importance. The freshwater planarian Schmidtea mediterranea provides an attractive system to study these processes because its hermaphroditic reproductive system (RS) arises post-embryonically and when lost can be fully and functionally regenerated from the proliferation and regulation of experimentally accessible stem and progenitor cells. By controlling the function of a nuclear hormone receptor gene (nhr-1), we established conditions in which to study the formation, maintenance and regeneration of both germline and somatic tissues of the planarian RS. We found that nhr-1(RNAi) not only resulted in the gradual degeneration and complete loss of the adult hermaphroditic RS, but also in the significant downregulation of a large cohort of genes associated with lipid metabolism. One of these, Smed-acs-1, a homologue of Acyl-CoA synthetase, was indispensable for the development, maintenance and regeneration of the RS, but not for the homeostasis or regeneration of other somatic tissues. Remarkably, supplementing nhr-1(RNAi) animals with either bacterial Acyl-CoA synthetase or the lipid metabolite Acetyl-CoA rescued the phenotype restoring the maintenance and function of the hermaphroditic RS. Our findings uncovered a likely evolutionarily conserved role for nuclear hormone receptors and lipid metabolism in the regulation of stem and progenitor cells required for the long-term maintenance and regeneration of animal reproductive organs, tissues and cells.

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Section: Discussionmentioning

confidence: 99%

A nuclear hormone receptor and lipid metabolism axis are required for the maintenance and regeneration of reproductive organs

Zhang

Guo

Guerrero‐Hernández

et al. 2018

Preprint

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“…Concerning reproduction, increasing male age was associated with two major risk factors: first, decline in fertility and second, health impairments of children fathered by men of advanced age (Sharma et al ., ; Gromoll et al ., ). The suggested age‐associated decline in fertility was attributed to decreased sperm parameters, for example sperm counts and sperm motility (Eskenazi et al ., ; Kühnert & Nieschlag, ; Begueria et al ., ; Gunes et al ., ). Additional data for declining germ cell numbers and testicular ageing were provided by Holstein et al .…”

Section: Introductionmentioning

confidence: 97%

Ageing in men with normal spermatogenesis alters spermatogonial dynamics and nuclear morphology in Sertoli cells

et al. 2019

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Background: Ageing in men is believed to be associated with fertility decline and elevated risk of congenital disorders for the offspring. The previous studies also reported reduced germ and Sertoli cell numbers in older men. However, it is not clear whether ageing in men with normal spermatogenesis affects the testis and germ cell population dynamics in a way sufficient for transmitting adverse age effects to the offspring. Objectives: We examined men with normal spermatogenesis at different ages concerning effects on persisting testicular cell types, that is the germ line and Sertoli cells, as these cell populations are prone to be exposed to age effects. Material and methods: Ageing was assessed in testicular biopsies of 32 patients assigned to three age groups: (i) 28.8 AE 2.7 years; (ii) 48.1 AE 1 years; and (iii) 70.9 AE 6.2 years, n = 8 each, with normal spermatogenesis according to the Bergmann-Kliesch score, and in a group of meiotic arrest patients (29.9 AE 3.8 years, n = 8) to decipher potential links between different germ cell types. Besides morphometry of seminiferous tubules and Sertoli cell nuclei, we investigated spermatogenic output/efficiency, and dynamics of spermatogonial populations via immunohistochemistry for MAGE A4, PCNA, CREM and quantified A-pale/A-dark spermatogonia. Results: We found a constant spermatogenic output (CREM-positive round spermatids) in all age groups studied. In men beyond their mid-40s (group 2), we detected increased nuclear and nucleolar size in Sertoli cells, indirectly indicating an elevated protein turnover. From the 7th decade (group 3) of life onwards, testes showed increased proliferation of undifferentiated spermatogonia, decreased spermatogenic efficiency and elevated numbers of proliferating A-dark spermatogonia. Discussion and conclusion: Maintaining normal sperm output seems to be an intrinsic determinant of spermatogenesis. Ageing appears to affect this output and might provoke compensatory proliferation increase in A spermatogonia which, in turn, might hamper germ cell integrity.

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“…Because of this deterioration, hormone production and spermatogenesis changes with too. As a result, these changes in spermatozoa increase with ageing (Gunes, Hekim, Arslan, & Asci, ).…”

Section: Discussionmentioning

confidence: 99%

The protective role of melatonin and curcumin in the testis of young and aged rats

et al. 2018

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We aimed to investigate the effect of melatonin and curcumin treatment on oxidative stress, apoptosis, and histology of testicular tissue in our study. Four groups were formed using young (4 months old, n = 6) and aged (20–22 months old, n = 18) male Wistar albino rats: (a) Young control (1% ethanol:phosphate‐buffered saline [PBS], subcutaneously [s.c.]); (b) Aged control (CTL; n = 6, 1% ethanol:PBS, s.c.); (c) Aged Melatonin (MLT; n = 6, 10 mg/kg, s.c.); (d) Aged Curcumin (CUR; n = 6, 30 mg/kg, i.p.). At the end of 21 days, the rats were sacrificed, and testicular tissues were removed. Malondialdehyde (MDA) in the testicular tissue was determined with thiobarbituric acid reactive substances formation, and glutathione (GSH) was determined with modified Ellman method; testosterone level was determined with chemiluminescence method and histologic changes were determined with Haematoxylin‐Eosin and Johnsen's scoring; Apoptotic cell counts were made with TUNEL staining of seminiferous tubule in testis. With ageing, MDA level increased in testicular tissue, but GSH and blood testosterone levels decreased. Melatonin treatment for aged rats significantly decreased Paired total testicular/body weight ratio compared to aged control group (p < 0.05). Curcumin treatment for aged rats significantly increased GSH level compared to the aged control group (p < 0.05). Besides, melatonin and curcumin treatment significantly decreased the number of apoptotic cells and significantly increased Johnsen's score (p < 0.05).

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Effects of aging on the male reproductive system

Cited by 195 publications

References 146 publications

A nuclear hormone receptor and lipid metabolism axis are required for the maintenance and regeneration of reproductive organs

A nuclear hormone receptor and lipid metabolism axis are required for the maintenance and regeneration of reproductive organs

Ageing in men with normal spermatogenesis alters spermatogonial dynamics and nuclear morphology in Sertoli cells

The protective role of melatonin and curcumin in the testis of young and aged rats

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