SIRT1 Expression and Regulation in the Primate Testis

The epigenetic mechanisms controlling germ cell development and differentiation are still not well understood. Sirtuin-1 (SIRT1) is a nicotinamide adenosine dinucleotide (NAD)-dependent histone deacetylase and belongs to the sirtuin family of deacetylases. It catalyzes the removal of acetyl groups from a number of protein substrates. Some studies reported a role of SIRT1 in the central and peripheral regulation of reproduction in various non-primate species. However, testicular SIRT1 expression and its possible role in the testis have not been analyzed in primates. Here, we document expression of SIRT1 in testes of different primates and some non-primate species. SIRT1 is expressed mainly in the cells of seminiferous tubules, particularly in germ cells. The majority of SIRT1-positive germ cells were in the meiotic and postmeiotic phase of differentiation. However, SIRT1 expression was also observed in selected premeiotic germ cells, i.e., spermatogonia. SIRT1 co-localized in spermatogonia with irisin, an endocrine factor specifically expressed in primate spermatogonia. In marmoset testicular explant cultures, SIRT1 transcript levels are upregulated by the addition of irisin as compared to untreated controls explants. Rhesus macaques are seasonal breeders with high testicular activity in winter and low testicular activity in summer. Of note, SIRT1 mRNA and SIRT1 protein expression are changed between nonbreeding (low spermatogenesis) and breeding (high spermatogenesis) season. Our data suggest that SIRT1 is a relevant factor for the regulation of spermatogenesis in primates. Further mechanistic studies are required to better understand the role of SIRT1 during spermatogenesis.

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Role of SIRT1 in HIV-associated kidney disease

AJP Renal Physiology ◽

10.1152/ajprenal.00140.2020 ◽

2020 ◽

Vol 319 (2) ◽

pp. F335-F344 ◽

Cited By ~ 1

Author(s):

Xuan Wang ◽

Ruijie Liu ◽

Weijia Zhang ◽

Deborah P. Hyink ◽

Gokul C. Das ◽

...

Keyword(s):

Kidney Disease ◽

Drug Targets ◽

Cell Injury ◽

Kidney Diseases ◽

Sirtuin 1 ◽

Kidney Cells ◽

Sirt1 Expression ◽

Hiv 1

Human immunodeficiency virus (HIV) infection of kidney cells can lead to HIV-associated nephropathy (HIVAN) and aggravate the progression of other chronic kidney diseases. Thus, a better understanding of the mechanisms of HIV-induced kidney cell injury is needed for effective therapy against HIV-induced kidney disease progression. We have previously shown that the acetylation and activation of key inflammatory regulators, NF-κB p65 and STAT3, were increased in HIVAN kidneys. Here, we demonstrate the key role of sirtuin 1 (SIRT1) deacetylase in the regulation of NF-κB and STAT3 activity in HIVAN. We found that SIRT1 expression was reduced in the glomeruli of human and mouse HIVAN kidneys and that HIV-1 gene expression was associated with reduced SIRT1 expression and increased acetylation of NF-κB p65 and STAT3 in cultured podocytes. Interestingly, SIRT1 overexpression, in turn, reduced the expression of negative regulatory factor in podocytes stably expressing HIV-1 proviral genes, which was associated with inactivation of NF-κB p65 and a reduction in HIV-1 long terminal repeat promoter activity. In vivo, the administration of the small-molecule SIRT1 agonist BF175 or inducible overexpression of SIRT1 specifically in podocytes markedly attenuated albuminuria, kidney lesions, and expression of inflammatory markers in Tg26 mice. Finally, we showed that the reduction in SIRT1 expression by HIV-1 is in part mediated through miR-34a expression. Together, our data provide a new mechanism of SIRT1 regulation and its downstream effects in HIV-1-infected kidney cells and indicate that SIRT1/miR-34a are potential drug targets to treat HIV-related kidney disease.

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De novo morphogenesis of testis tissue: an improved bioassay to investigate the role of VEGF165 during testis formation

Reproduction ◽

10.1530/rep-13-0303 ◽

2014 ◽

Vol 148 (1) ◽

pp. 109-117 ◽

Cited By ~ 17

Author(s):

Camila Dores ◽

Ina Dobrinski

Keyword(s):

Blood Vessel ◽

Cell Suspension ◽

Germ Cells ◽

De Novo ◽

Donor Cell ◽

Seminiferous Tubules ◽

Tissue Formation ◽

Tubule Formation ◽

Testis Tissue

De novo formation of testis tissue from single-cell suspensions allows manipulation of different testicular compartments before grafting to study testicular development and the spermatogonial stem cell niche. However, the low percentages of newly formed seminiferous tubules supporting complete spermatogenesis and lack of a defined protocol have limited the use of this bioassay. Low spermatogenic efficiency in de novo formed tissue could result from the scarcity of germ cells in the donor cell suspension, cell damage caused by handling or from hypoxia during tissue formation in the host environment. In this study, we compared different proportions of spermatogonia in the donor cell suspension and the use of Matrigel as a scaffold to support de novo tissue formation and spermatogenesis. Then, we used the system to investigate the role of vascular endothelial growth factor 165 (VEGF165) during testicular morphogenesis on blood vessel and seminiferous tubule formation, and on presence of germ cells in the de novo developed tubules. Our results show that donor cell pellets with 10×106 porcine neonatal testicular cells in Matrigel efficiently formed testis tissue de novo. Contrary to what was expected, the enrichment of the cell suspension with germ cells did not result in higher numbers of tubules supporting spermatogenesis. The addition of VEGF165 did not improve blood vessel or tubule formation, but it enhanced the number of tubules containing spermatogonia. These results indicate that spermatogenic efficiency was improved by the addition of Matrigel, and that VEGF165 may have a protective role supporting germ cell establishment in their niche.

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The Prognostic Role of SIRT1-Autophagy Axis in Gastric Cancer

Disease Markers ◽

10.1155/2016/6869415 ◽

2016 ◽

Vol 2016 ◽

pp. 1-11 ◽

Cited By ~ 10

Author(s):

Guanglin Qiu ◽

Xuqi Li ◽

Chao Wei ◽

Xiangming Che ◽

Shicai He ◽

...

Keyword(s):

Prognostic Indicator ◽

Beclin 1 ◽

Sirtuin 1 ◽

Clinicopathological Parameters ◽

Poor Survival ◽

Free Survival ◽

Sirt1 Expression ◽

Transmission Electron ◽

The Relationship

Aim. Sirtuin 1 (SIRT1) can induce autophagy through deacetylation of Beclin-1 and other autophagy mediators. However, the relationship between SIRT1 and autophagy in GC has not been defined. Therefore, the aim of this study was to confirm the prognostic value of SIRT1 and Beclin-1 and their relationship in GC patients. Methods. Transmission electron microscopy (TEM) was performed to examine the autophagy in GC patients. Immunohistochemistry was used to examine the expression of SIRT1, Beclin-1 in GC, and adjacent nonneoplastic mucosa. Results. In 7 out of 8 GC patients’ samples examined by TEM, more autophagic vesicles were observed in GC tissues compared to adjacent nonneoplastic mucosa tissue. A positive correlation between SIRT1 and Beclin-1 expression was observed. Furthermore, Beclin-1 or SIRT1 expression alone or their combined expression were significantly correlated with advanced clinicopathological parameters. High Beclin-1 and SIRT1 expression alone and their combined high expression predicted shorter overall survival and relapse-free survival. Both high Beclin-1 and SIRT1 expressions were independent prognostic factors for poor survival of GC. Conclusions. Based on our results we can conclude that SIRT1 and Beclin-1 expression alone or in combination can be used as prognostic indicator and may represent new therapeutic targets in GC.

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The insulin sensitiser metformin regulates chicken Sertoli and germ cell populations

Reproduction ◽

10.1530/rep-15-0565 ◽

2016 ◽

Vol 151 (5) ◽

pp. 527-538 ◽

Cited By ~ 10

Author(s):

M Faure ◽

E Guibert ◽

S Alves ◽

B Pain ◽

C Ramé ◽

...

Keyword(s):

Germ Cells ◽

Sertoli Cells ◽

Energy Content ◽

Morphological Changes ◽

Seminiferous Tubules ◽

Reduce Food Intake ◽

Testicular Weight

Abstract Metformin, an insulin sensitiser from the biguanide family of molecules, is used for the treatment of insulin resistance in type 2 diabetes individuals. It increases peripheral glucose uptake and may reduce food intake. Based on the tight link between metabolism and fertility, we investigated the role of metformin on testicular function using in vitro culture of Sertoli cells and seminiferous tubules, complemented by in vivo data obtained following metformin administration to prepubertal chickens. In vitro, metformin treatment reduced Sertoli cell proliferation without inducing apoptosis and morphological changes. The metabolism of Sertoli cells was affected because lactate secretion by Sertoli cells increased approximately twofold and intracellular free ATP was negatively impacted. Two important pathways regulating proliferation and metabolism in Sertoli cells were assayed. Metformin exposure was not associated with an increased phosphorylation of AKT or ERK. There was a 90% reduction in the proportion of proliferating germ cells after a 96-h exposure of seminiferous tubule cultures to metformin. In vivo, 6-week-old chickens treated with metformin for 3 weeks exhibited reduced testicular weight and a 50% decrease in testosterone levels. The expression of a marker of undifferentiated germ cells was unchanged in contrast to the decrease in expression of ‘protamine’, a marker of differentiated germ cells. In conclusion, these results suggest that metformin affects the testicular energy content and the proliferative ability of Sertoli and germ cells. Reproduction (2016) 151 527–538

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Human NANOS1 Represses Apoptosis by Downregulating Pro-Apoptotic Genes in the Male Germ Cell Line

International Journal of Molecular Sciences ◽

10.3390/ijms21083009 ◽

2020 ◽

Vol 21 (8) ◽

pp. 3009

Author(s):

Damian M. Janecki ◽

Erkut Ilaslan ◽

Maciej J. Smialek ◽

Marcin P. Sajek ◽

Maciej Kotecki ◽

...

Keyword(s):

Cell Cycle ◽

Germ Cell ◽

Cell Line ◽

Germ Cells ◽

Male Germ Cell ◽

Seminiferous Tubules ◽

Sequencing Analysis ◽

Germ Cell Line ◽

Apoptotic Genes

While two mouse NANOS paralogues, NANOS2 and NANOS3, are crucial for maintenance of germ cells by suppression of apoptosis, the mouse NANOS1 paralogue does not seem to regulate these processes. Previously, we described a human NANOS1 p.[(Pro34Thr);(Ser83del)] mutation associated with the absence of germ cells in seminiferous tubules of infertile patients, which might suggest an anti-apoptotic role of human NANOS1. In this study, we aimed to determine a potential influence of human NANOS1 on the maintenance of TCam-2 model germ cells by investigating proliferation, cell cycle, and apoptosis. Constructs encoding wild-type or mutated human NANOS1 were used for transfection of TCam-2 cells, in order to investigate the effect of NANOS1 on cell proliferation, which was studied using a colorimetric assay, as well as apoptosis and the cell cycle, which were measured by flow cytometry. RNA-Seq (RNA sequencing) analysis followed by RT-qPCR (reverse transcription and quantitative polymerase chain reaction) was conducted for identifying pro-apoptotic genes repressed by NANOS1. Here, we show that overexpression of NANOS1 downregulates apoptosis in TCam-2 cells. Moreover, we found that NANOS1 represses a set of pro-apoptotic genes at the mRNA level. We also found that the infertility-associated p.[(Pro34Thr);(Ser83del)] mutation causes NANOS1 to functionally switch from being anti-apoptotic to pro-apoptotic in the human male germ cell line. Thus, this report is the first to show an anti-apoptotic role of NANOS1 exerted by negative regulation of mRNAs of pro-apoptotic genes.

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Expression of the adaptor protein m-Numb in mouse male germ cells

Reproduction ◽

10.1530/rep-06-0062 ◽

2006 ◽

Vol 132 (6) ◽

pp. 887-897 ◽

Cited By ~ 13

Author(s):

Serena Corallini ◽

Stefania Fera ◽

Laura Grisanti ◽

Ilaria Falciatori ◽

Barbara Muciaccia ◽

...

Keyword(s):

Cell Fate ◽

Germ Cells ◽

Adaptor Protein ◽

Notch Signaling Pathway ◽

Seminiferous Tubules ◽

Confocal Immunofluorescence Microscopy ◽

Confocal Immunofluorescence ◽

Evolutionarily Conserved ◽

Asymmetric Partitioning

Numb is an adaptor protein that is asymmetrically inherited at mitosis and controls the fate of sibling cells in different species. The role of m-Numb (mammalian Numb) as an important cell fate-determining factor has extensively been described mostly in neural tissues, particularly in progenitor cells, in the mouse. Biochemical and genetic analyses have shown that Numb acts as an inhibitor of the Notch signaling pathway, an evolutionarily conserved pathway involved in the control of cell proliferation, differentiation, and apoptosis. In the present study, we sought to determine m-Numb distribution in germ cells in the postnatal mouse testis. We show that all four m-Numb isoforms are widely expressed during postnatal testis development. By reverse transcriptase-PCR and western blot analyses, we further identify p71 as the predominantly expressed isoform in germ cells. Moreover, we demonstrate through co-immunoprecipitation studies that m-Numb physically associates with Ap2a1, a component of the endocytotic clathrin-coated vesicles. Finally, we employed confocal immunofluorescence microscopy of whole mount seminiferous tubules and isolated germ cells to gain more insight into the subcellular localization of m-Numb. These morphological analyses confirmed m-Numb and Ap2a1 co-localization. However, we did not observe asymmetric localization of m-Numb neither in mitotic spermatogonial stem cells nor in more differentiated spermatogonial cells, suggesting that spermatogonial stem cell fate in the mouse does not rely on asymmetric partitioning of m-Numb.

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PKCδ Mediates NF-κB Inflammatory Response and Downregulates SIRT1 Expression in Liver Fibrosis

International Journal of Molecular Sciences ◽

10.3390/ijms20184607 ◽

2019 ◽

Vol 20 (18) ◽

pp. 4607 ◽

Cited By ~ 5

Author(s):

Lee ◽

Kim ◽

Lee ◽

Kwon

Keyword(s):

Inflammatory Response ◽

Hepatic Cirrhosis ◽

Regulatory Mechanism ◽

Sirtuin 1 ◽

Sirt1 Expression ◽

Kinase C ◽

Promising Target ◽

Ccl4 Treatment ◽

Fibrotic Diseases

The precise mechanism of hepatic cirrhosis remains largely unclear. In particular, a potential regulatory mechanism by which protein kinase C-delta (PKCδ ) affects profibrogenic gene expression involved in hepatic cirrhosis has never been explored. In the present study, we investigated whether PKCδ activation is involved in liver inflammatory fibrosis in both lipopolysaccharide (LPS)-treated RAW 264.7 and CCl4-treated mice. PKCδ was strongly activated by LPS or CCl4 treatment and consequently stimulated nuclear factor (NF)-κB inflammatory response. Interestingly, the activation of PKCδ negatively regulated sirtuin-1 (SIRT1) expression, whereas PKCδ suppression by PKCδ peptide inhibitor V1-1 or siRNA dramatically increased SIRT1 expression. Furthermore, we showed that the negative regulation of PKCδ leads to a decrease in SIRT1 expression. To our knowledge, these results are the first demonstration of the involvement of PKCδ in modulating NF-κB through SIRT1 signaling in fibrosis in mice, suggesting a novel role of PKCδ in inflammatory fibrosis. The level of NF-κB p65 in the nucleus was also negatively regulated by SIRT1 activity. We showed that the inhibition of PKCδ promoted SIRT1 expression and decreased p65 levels in the nucleus through deacetylation. Moreover, the inactivation of PKCδ with V1-1 dramatically suppressed the inflammatory fibrosis, indicating that PKCδ represents a promising target for treating fibrotic diseases like hepatic cirrhosis.

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Role of SIRT1 and Progesterone Resistance in Normal and Abnormal Endometrium

The Journal of Clinical Endocrinology & Metabolism ◽

10.1210/clinem/dgab753 ◽

2021 ◽

Author(s):

Tae Hoon Kim ◽

Steven L Young ◽

Tsutomu Sasaki ◽

Jeffrey L Deaton ◽

David P Schammel ◽

...

Keyword(s):

Cellular Response ◽

Sirtuin 1 ◽

Endometriotic Lesion ◽

Mouse Uterus ◽

Normal Endometrium ◽

Sirt1 Expression ◽

Progesterone Resistance ◽

Sirt1 Inhibitor ◽

Physiologic Role

Abstract Context Progesterone resistance, a known pathologic condition associated with a reduced cellular response to progesterone and heightened estrogen responses, appears to have a normal physiologic role in mammalian reproduction. The molecular mechanism responsible for progesterone resistance in normal and abnormal endometrium remains unclear. Objective To examine the roles of Sirtuin-1 (SIRT1) in normal endometrium as well as endometrium associated with infertility and endometriosis, as an epigenetic modulator associated with progesterone resistance. Methods SIRT1 expression was examined by Western blot, RT-qPCR and immunohistochemistry in mouse uterus and human endometrium. Mice with uterine specific Sirt1 overexpression were developed to examine SIRT1’s role in endometrial function and endometriosis development. EX-527, a SIRT1 inhibitor, and SRT1720, a SIRT1 agonist, were also used to evaluate SIRT1 effect on endometriosis. Results In normal healthy women, endometrial SIRT1 is expressed only during menses. SIRT1 was dramatically overexpressed in the endometrium from women with endometriosis in both the epithelium and strom. In mice, SIRT1 is expressed at the time of implantation between day 4.5 and 5.5 of pregnancy. Overexpression of SIRT1 (Sirt1 over) in the mouse uterus leads to subfertility due to implantation failure and decidualization defects and progesterone resistance. SIRT1 overexpression in endometriotic lesion promotes worsening endometriosis development. EX-527 (SIRT1 inhibitor) significantly reduced the number of endometriotic lesions in the mouse endometriosis model. Conclusions SIRT1 expression and progesterone resistance appears to play -roles in normal endometrial functions. Aberrant SIRT1 expression contributes to progesterone resistance and may participate in the pathophysiology of endometriosis. SIRT1 is a novel and targetable protein for the diagnosis as well as treatment of endometriosis and the associated infertility seen in this disease.

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The essential role of intraflagellar transport protein IFT81 in male mice spermiogenesis and fertility

AJP Cell Physiology ◽

10.1152/ajpcell.00450.2019 ◽

2020 ◽

Vol 318 (6) ◽

pp. C1092-C1106

Author(s):

Wei Qu ◽

Shuo Yuan ◽

Chao Quan ◽

Qian Huang ◽

Qi Zhou ◽

...

Keyword(s):

Germ Cells ◽

Cross Sections ◽

Essential Role ◽

Intraflagellar Transport ◽

Mutant Mice ◽

Seminiferous Tubules ◽

Fibrous Sheath ◽

Homozygous Mutant ◽

Cilia And Flagella

Intraflagellar transport (IFT) is an evolutionarily conserved mechanism that is indispensable for the formation and maintenance of cilia and flagella; however, the implications and functions of IFT81 remain unknown. In this study, we disrupted IFT81 expression in male germ cells starting from the spermatocyte stage. As a result, homozygous mutant males were completely infertile and displayed abnormal sperm parameters. In addition to oligozoospermia, spermatozoa presented dysmorphic and nonfunctional flagella. Histological examination of testes from homozygous mutant mice revealed abnormal spermiogenesis associated with sloughing of germ cells and the presence of numerous multinucleated giant germ cells (symblasts) in the lumen of seminiferous tubules and epididymis. Moreover, only few elongated spermatids and spermatozoa were seen in analyzed cross sections. Transmission electron microscopy showed a complete disorganization of the axoneme and para-axonemal structures such as the mitochondrial sheath, fibrous sheath, and outer dense fibers. In addition, numerous vesicles that contain unassembled microtubules were observed within developing spermatids. Acrosome structure analysis showed normal appearance, thus excluding a crucial role of IFT81 in acrosome biogenesis. These observations showed that IFT81 is an important member of the IFT process during spermatogenesis and that its absence is associated with abnormal flagellum formation leading to male infertility. The expression levels of several IFT components in testes, including IFT20, IFT25, IFT27, IFT57, IFT74, and IFT88, but not IFT140, were significantly reduced in homozygous mutant mice. Overall, our study demonstrates that IFT81 plays an essential role during spermatogenesis by modulating the assembly and elongation of the sperm flagella.

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Use of riboflavinum and magnesium citrate in obstetrics and gynecology

GYNECOLOGY ◽

10.26442/20795696.2018.6.000045 ◽

2018 ◽

Vol 20 (6) ◽

pp. 60-66

Author(s):

O A Gromova ◽

I Yu Torshin ◽

N K Tetruashvili

Keyword(s):

Thrombus Formation ◽

Sirtuin 1 ◽

Obstetrics And Gynecology ◽

Inflammatory Factor ◽

Vitamin B2 ◽

Magnesium Citrate ◽

Fetal Malformations ◽

Folate Cycle ◽

Pro Inflammatory Cytokines

Low provision of cells with vitamin B2 and magnesium leads to a decrease in the activity of the sirtuin-1 deacetylase and an increase in the activity of the pro-inflammatory factor NF-kB, a decrease in the levels of glutathione, an increase in the levels of homocysteine, thrombus formation, the activity of mitochondria, the development of migraine, convulsions and miscarriage. The role of riboflavin in the regulation of the folate cycle in the genotype MTHFR 677TT for the prevention of folatresistant fetal malformations, the advantages of an aqueous solution of riboflavin and magnesium citrate is considered. The data on titanium dioxide, which increases the level of pro-inflammatory cytokines IL-1b, IL-4, IL-5, IL-6, G-CSF, CCL-2, CCL-3, CCL-4, are presented.

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