RESUMO
Paternal epigenome regulates placental and fetal growth. However, the effect of paternal obesity on placenta and its subsequent effect on the fetus via sperm remains unknown. We previously discovered abnormal methylation of imprinted genes involved in placental and fetal development in the spermatozoa of obese rats. In the present study, elaborate epigenetic characterization of sperm, placenta, and fetus was performed. For 16 weeks, male rats were fed either control or a high-fat diet. Following mating studies, sperm, placenta, and fetal tissue were collected. Significant changes were observed in placental weights, morphology, and cell populations. Methylation status of imprinted genes-Igf2, Peg3, Cdkn1c, and Gnas in spermatozoa, correlated with their expression in the placenta and fetus. Placental DNA methylating enzymes and 5-methylCytosine levels increased. Furthermore, in spermatozoa, DNA methylation of a few genes involved in pathways associated with placental endocrine function-gonadotropin-releasing hormone, prolactin, estrogen, and vascular endothelial growth factor, correlated with their expression in placenta and fetus. Changes in histone-modifying enzymes were also observed in the placenta. Histone marks H3K4me3, H3K9me3, and H4ac were downregulated, while H3K27me3 and H3ac were upregulated in placentas derived from obese male rats. This study shows that obesity-related changes in sperm methylome translate into abnormal expression in the F1-placenta fathered by the obese male, presumably affecting placental and fetal development.
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Placenta , Fator A de Crescimento do Endotélio Vascular , Gravidez , Masculino , Feminino , Animais , Ratos , Placenta/metabolismo , Sêmen/metabolismo , Metilação de DNA , Obesidade/metabolismo , Feto/metabolismo , Epigênese Genética , Expressão GênicaRESUMO
Current influenza vaccines, live attenuated or inactivated, do not protect against antigenically novel influenza A viruses (IAVs) of pandemic potential, which has driven interest in the development of universal influenza vaccines. Universal influenza vaccine candidates targeting highly conserved antigens of IAV nucleoprotein (NP) are promising as vaccines that induce T cell immunity, but concerns have been raised about the safety of inducing robust CD8 T cell responses in the lungs. Using a mouse model, we systematically evaluated effects of recombinant adenovirus vectors (rAd) expressing IAV NP (A/NP-rAd) or influenza B virus (IBV) NP (B/NP-rAd) on pulmonary inflammation and function after vaccination and following live IAV challenge. After A/NP-rAd or B/NP-rAd vaccination, female mice exhibited robust systemic and pulmonary vaccine-specific B cell and T cell responses and experienced no morbidity (e.g., body mass loss). Both in vivo pulmonary function testing and lung histopathology scoring revealed minimal adverse effects of intranasal rAd vaccination compared with unvaccinated mice. After IAV challenge, A/NP-rAd-vaccinated mice experienced significantly less morbidity, had lower pulmonary virus titers, and developed less pulmonary inflammation than unvaccinated or B/NP-rAd-vaccinated mice. Based on analysis of pulmonary physiology using detailed testing not previously applied to the question of T cell damage, mice protected by vaccination also had better lung function than controls. Results provide evidence that, in this model, adenoviral universal influenza vaccine does not damage pulmonary tissue. In addition, adaptive immunity, in particular, T cell immunity in the lungs, does not cause damage when restimulated but instead mitigates pulmonary damage following IAV infection.IMPORTANCE Respiratory viruses can emerge and spread rapidly before vaccines are available. It would be a tremendous advance to use vaccines that protect against whole categories of viruses, such as universal influenza vaccines, without the need to predict which virus will emerge. The nucleoprotein (NP) of influenza virus provides a target conserved among strains and is a dominant T cell target. In animals, vaccination to NP generates powerful T cell immunity and long-lasting protection against diverse influenza strains. Concerns have been raised, but not evaluated experimentally, that potent local T cell responses might damage the lungs. We analyzed lung function in detail in the setting of such a vaccination. Despite CD8 T cell responses in the lungs, lungs were not damaged and functioned normally after vaccination alone and were protected upon subsequent infection. This precedent provides important support for vaccines based on T cell-mediated protection, currently being considered for both influenza and SARS-CoV-2 vaccines.
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Adenoviridae , Vetores Genéticos , Vírus da Influenza B , Vacinas contra Influenza , Pulmão , Infecções por Orthomyxoviridae , Adenoviridae/genética , Adenoviridae/imunologia , Animais , Linfócitos B/imunologia , Linfócitos B/patologia , Modelos Animais de Doenças , Feminino , Vetores Genéticos/genética , Vetores Genéticos/imunologia , Imunidade Celular , Vírus da Influenza B/genética , Vírus da Influenza B/imunologia , Vacinas contra Influenza/genética , Vacinas contra Influenza/imunologia , Pulmão/imunologia , Pulmão/patologia , Pulmão/virologia , Camundongos , Infecções por Orthomyxoviridae/genética , Infecções por Orthomyxoviridae/imunologia , Infecções por Orthomyxoviridae/patologia , Infecções por Orthomyxoviridae/prevenção & controle , Linfócitos T/imunologia , Linfócitos T/patologiaRESUMO
The current novel coronavirus disease 2019 (COVID-19) pandemic is revealing profound differences between men and women in disease outcomes worldwide. In the United States, there has been inconsistent reporting and analyses of male-female differences in COVID-19 cases, hospitalizations, and deaths. We seek to raise awareness about the male-biased severe outcomes from COVID-19, highlighting the mechanistic differences including in the expression and activity of angiotensin-converting enzyme 2 (ACE2) as well as in antiviral immunity. We also highlight how sex differences in comorbidities, which can be associated with both age and race, impact male-biased outcomes from COVID-19.
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Infecções por Coronavirus/epidemiologia , Pneumonia Viral/epidemiologia , Fatores Sexuais , Enzima de Conversão de Angiotensina 2 , COVID-19 , Comorbidade , Infecções por Coronavirus/metabolismo , Infecções por Coronavirus/fisiopatologia , Hospitalização , Humanos , Pandemias , Peptidil Dipeptidase A/metabolismo , Pneumonia Viral/metabolismo , Pneumonia Viral/fisiopatologia , Receptores Virais/metabolismo , Estados Unidos/epidemiologiaRESUMO
STUDY QUESTION: What is the sperm DNA methylation status of imprinted genes in male partners from couples experiencing recurrent pregnancy loss (RPL)? SUMMARY ANSWER: Aberrations in sperm DNA methylation status of several imprinted genes, such as insulin like growth factor-2-H19 differentially methylated region (IGF2-H19 DMR), intergenic differentially methylated region (IG-DMR), mesoderm specific transcript (MEST), zinc finger protein which regulates apoptosis and cell cycle arrest (ZAC), DMR in intron 10 of KCNQ1 gene (KvDMR), paternally expressed gene 3 (PEG3) and paternally expressed gene 10 (PEG10), as well as decreased sperm global 5-methylcytosine (5mC) levels, are associated with RPL. WHAT IS KNOWN ALREADY: RPL is defined as loss of two or more pregnancies, affecting 1-2% of couples of reproductive age. Although there are several maternal and paternal aetiological factors contributing to RPL, nearly 50% of the cases remain idiopathic. Thus, there is a need to identify putative paternal factors that could be contributing towards pregnancy loss in cases of idiopathic RPL. STUDY DESIGN, SIZE, DURATION: In this case-control study, 112 couples undergoing RPL with no identifiable cause were recruited from September 2015 to May 2018. The control group comprised of 106 healthy proven fertile couples with no history of infertility or miscarriage. PARTICIPANTS/MATERIALS, SETTING, METHODS: In this study, we investigated the paternal genetic and epigenetic factors that could be associated with RPL. We studied DNA methylation, by pyrosequencing, of selected imprinted genes implicated in embryo development, such as IGF2-H19 DMR, IG-DMR, MEST, ZAC, KvDMR, PEG3, PEG10 and small nuclear ribonucleoprotein polypeptide N (SNRPN) in sperm of men whose partners present RPL. Global DNA methylation in sperm was evaluated by studying 5mC content and long interspersed nuclear element 1 (LINE1) promoter methylation. We also studied polymorphisms by pyrosequencing in the IGF2-H19 DMR as well in the IGF2 promoter in both groups. MAIN RESULTS AND THE ROLE OF CHANCE: In the RPL group, we found a significant decrease in the global sperm 5mC levels and significant decrease in DNA methylation at three CpG sites in LINE1 promoter. For IGF2-H19 DMR and IG-DMR, a significant decrease in sperm DNA methylation at specific CpG sites was observed in RPL group. For maternally imprinted genes like MEST, ZAC, KvDMR, PEG3 and PEG10 hypermethylation was noted. Polymorphism studies for IGF2-H19 DMR and IGF2 revealed significant differences in the genotypic frequencies in males. LIMITATIONS, REASONS FOR CAUTION: In this study, we analysed the methylation levels of selected candidate imprinted genes implicated in embryo development. Detection of methylation changes occurring at the genome-wide level may reveal further candidate genes having a better distinction between the control and study groups. WIDER IMPLICATIONS OF THE FINDINGS: Our study demonstrates that certain polymorphisms and aberrant sperm methylation status in imprinted genes are associated with RPL and could contribute to the aetiology of RPL. This study suggests that investigation of paternal genetic and epigenetic factors could be useful in identification of possible causes of idiopathic RPL. STUDY FUNDING/COMPETING INTEREST(S): This study was funded by Department of Science and Technology-Science and Engineering Research Board (EMR/2014/000145) and National Institute for Research in Reproductive Health intramural funds (RA/872/01-2020). All authors declare no conflict of interest. TRIAL REGISTRATION NUMBER: N/A.
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Aborto Habitual , RNA Longo não Codificante , Aborto Habitual/genética , Aborto Habitual/metabolismo , Estudos de Casos e Controles , Metilação de DNA , Feminino , Impressão Genômica , Humanos , Fator de Crescimento Insulin-Like II/genética , Fator de Crescimento Insulin-Like II/metabolismo , Masculino , Gravidez , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Espermatozoides/metabolismoRESUMO
Obesity, an established risk factor for male subfertility or infertility, is primarily due to genetic and environmental causes. Our earlier studies have shown differential effects of high-fat diet-induced- (DIO) and genetically inherited- (GIO) obesity on DNA methylation in male germline and its subsequent effect on fertility. Here, we hypothesized that the effects of DIO and GIO on histone modifications in male germline could also contribute to fertility defects. We observed that DIO affected both active (H3K4me3, H3ac, and H4ac) and repressive (H3K9me3 and H3K27me3) histone marks in testis and their cell types, whereas GIO solely altered acetylated histones. This correlated with the deregulation of histone-modifying enzymes in the testis of both obese groups. Further, we also observed a decrease in chromatin remodelers in the testis of the DIO group, which were increased in the GIO group. Besides, there was an increase in core histones and a decrease in histone marks along with protamine deficiency in spermatozoa of the DIO group, whereas only H3K4me3 levels were increased in spermatozoa of the GIO group. Moreover, we observed alterations in the expression and enrichment patterns of a few developmental genes harbored by the active histone mark in resorbed embryos and spermatozoa of DIO rats. Together these epigenetic defects in the male germline could alter sperm quality and cause fertility defects in these obese groups. Differential changes in two obese groups could also be attributed to differences in their pathophysiological variations. Our study highlights epigenetic differences between DIO and GIO in the male germline and their subsequent impact on male fertility.
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Células Germinativas , Histonas , Animais , Dieta Hiperlipídica/efeitos adversos , Epigênese Genética , Células Germinativas/metabolismo , Histonas/metabolismo , Masculino , Obesidade/genética , Obesidade/metabolismo , Ratos , Espermatozoides/metabolismoRESUMO
Spermatogenesis occurs in the seminiferous epithelium that shows the presence of estrogen receptors alpha (ERα) and beta (ERß), both of which regulate gene transcription by binding to the DNA. Estrogen responsive phases of spermatogenesis are well documented; however, the genes regulated remain inexplicit. To study the regulation of genes by estrogen in male germ cells, we performed chromatin immunoprecipitation (ChIP) sequencing for ERα and ERß under normal physiological conditions. A total of 27 221 DNA binding regions were enriched with ERα and 20 926 binding sites with ERß. Majority of the peaks were present in the intronic regions and located 20â kb upstream or downstream from the transcription start site (TSS). Pathway analysis of the genes enriched by ChIP-Seq showed involvement in several biological pathways. Genes involved in pathways whose role in spermatogenesis is unexplored were validated; these included prolactin, GnRH, and oxytocin signaling. All the selected genes showed the presence of estrogen response elements (EREs) in their binding region and were also found to be significantly enriched by ChIP-qPCR. Functional validation using seminiferous tubule culture after treatment with estrogen receptor subtype-specific agonist and antagonist confirmed the regulation of these genes by estrogen through its receptors. The genes involved in these pathways were also found to be regulated by the respective receptor subtypes at the testicular level in our in vivo estrogen receptor agonist rat models. Our study provides a genome-wide map of ERα and ERß binding sites and identifies the genes regulated by them in the male germ cells under normal physiological conditions.
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Receptor alfa de Estrogênio/metabolismo , Receptor beta de Estrogênio/metabolismo , Estrogênios/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Genoma , Células Germinativas/metabolismo , Elementos de Resposta , Animais , Sítios de Ligação , Receptor alfa de Estrogênio/genética , Receptor beta de Estrogênio/genética , Células Germinativas/citologia , Masculino , Ligação Proteica , Ratos , Ratos Sprague-DawleyRESUMO
Prolactin is a peptide hormone known to have multiple functions. However, the role of prolactin has been extensively studied only in female physiology and its function in male reproduction still remains majorly unexplored. Studies in rodents and humans have demonstrated the presence of prolactin and its receptor in testes, thereby suggesting a possible role during spermatogenesis. Experimental evidences from prolactin and prolactin receptor deficient male rodent models as well as studies done in hypo- and hyper-prolactinemic males hint at neuroendocrine and reproductive abnormalities. Nonetheless, there still remains a lot of ambiguity on the exact role of prolactin and its receptor in male reproduction. This review summarizes in depth on the role of prolactin in spermatogenesis.
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Prolactina/metabolismo , Receptores da Prolactina/metabolismo , Reprodução , Animais , Humanos , Masculino , Modelos Animais , Transdução de Sinais , Testículo/metabolismoRESUMO
Sperm chromatin packaging is a very complex and highly regulated phenomenon. While most of the sperm chromatin is replaced by protamines, some are retained in nucleosomes. It is recently being recognised that these nucleosomes are intentionally retained and could be contributing to the expression of genes in the very early stages of embryogenesis. Endocrine disruption has been previously shown to affect reproductive outcome and sperm DNA methylation. This study aims to decipher the possibility of changes in nucleosome occupancy in sperm chromatin, induced by tamoxifen (selective oestrogen receptor modulator) and cyproterone acetate (androgen antagonist). We used next-generation sequencing approach (MNase-Seq) to identify changes in the nucleosome landscape of the spermatozoa. We demonstrated that endocrine disruption affects nucleosome occupancy at critical regions of the genome and many of them harbour genes relevant for embryogenesis. This study emphasises that environmental factors could affect embryo development by way of modulating male epigenetic factors.
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Disruptores Endócrinos/toxicidade , Nucleossomos/efeitos dos fármacos , Espermatozoides/efeitos dos fármacos , Animais , Acetato de Ciproterona , Impressão Genômica , Masculino , Nucleossomos/metabolismo , Ratos Sprague-Dawley , Espermatozoides/metabolismo , Tamoxifeno , Sítio de Iniciação de TranscriçãoRESUMO
Actin remodeling is a vital process for signaling, movement and survival in all cells. In the testes, extensive actin reorganization occurs at spermatid-Sertoli cell junctions during sperm release (spermiation) and at inter Sertoli cell junctions during restructuring of the blood testis barrier (BTB). During spermiation, tubulobulbar complexes (TBCs), rich in branched actin networks, ensure recycling of spermatid-Sertoli cell junctional molecules. Similar recycling occurs during BTB restructuring around the same time as spermiation occurs. Actin related protein 2/3 complex is an essential actin nucleation and branching protein. One of its subunits, Arpc1b, was earlier found to be down-regulated in an estrogen-induced rat model of spermiation failure. Also, Arpc1b was found to be estrogen responsive through estrogen receptor beta in seminiferous tubule culture. Here, knockdown of Arpc1b by siRNA in adult rat testis led to defects in spermiation caused by failure in TBC formation. Knockdown also compromised BTB integrity and caused polarity defects of mature spermatids. Apart from these effects pertaining to Sertoli cells, Arpc1b reduction perturbed ability of germ cells to enter G2/M phase thus hindering cell division. In summary, Arpc1b, an estrogen responsive gene, is a regulator of spermiation, mature spermatid polarity, BTB integrity and cell division during adult spermatogenesis.
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Complexo 2-3 de Proteínas Relacionadas à Actina/fisiologia , Células de Sertoli/metabolismo , Espermatogênese/fisiologia , Espermatozoides/metabolismo , Citoesqueleto de Actina/metabolismo , Complexo 2-3 de Proteínas Relacionadas à Actina/antagonistas & inibidores , Complexo 2-3 de Proteínas Relacionadas à Actina/genética , Animais , Barreira Hematotesticular/fisiologia , Estradiol/fisiologia , Humanos , Masculino , Interferência de RNA , RNA Interferente Pequeno/genética , Ratos , Ratos Sprague-Dawley , Células de Sertoli/ultraestrutura , Contagem de Espermatozoides , Espermátides/metabolismo , Espermátides/ultraestrutura , Espermatócitos/metabolismo , Espermatócitos/ultraestrutura , Espermatozoides/ultraestruturaRESUMO
During cellular senescence, persistent growth arrest and changes in protein expression programs are accompanied by a senescence-associated secretory phenotype (SASP). In this study, we detected the upregulation of the SASP-related protein dipeptidyl peptidase 4 (DDP4) in human primary lung cells rendered senescent by exposure to ionizing radiation. DPP4 is an exopeptidase that plays a crucial role in the cleavage of various proteins, resulting in the loss of N-terminal dipeptides and proinflammatory effects. Interestingly, our data revealed an association between severe coronavirus disease 2019 (COVID-19) and DDP4, namely that DPP4 levels increased in the plasma of patients with COVID-19 and were correlated with age and disease progression. Although we could not determine the direct effect of DDP4 on viral replication, mechanistic studies in cell culture revealed a negative impact on the expression of the tight junction protein zonula occludens-1 (ZO-1), which contributes to epithelial barrier function. Mass spectrometry analysis indicated that DPP4 overexpressing cells exhibited a decrease in ZO-1 and increased expression of pro-inflammatory cytokines and chemokines. By investigating the effect of DPP4 on the barrier function of human primary cells, we detected an increase in ZO-1 using DPP4 inhibitors. These results provide an important contribution to our understanding of DPP4 in the context of senescence, suggesting that DPP4 plays a major role as part of the SASP. Our results provide evidence that cellular senescence, a hallmark of aging, has an important impact on respiratory infections.
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To determine if biological sex and age intersect to affect universal influenza vaccine-induced immunity, adult and aged male and female C57BL/6 mice were sequentially immunized with a chimeric-hemagglutinin (cHA) stalk-based H1 vaccine. Adult mice developed greater quantity and quality of H1-stalk antibodies, that were more cross-reactive with other group 1, but not group 2, influenza viruses, than aged mice. The vaccine did not induce neutralizing or hemagglutination inhibition antibodies, but rather antibody-dependent cellular cytotoxicity, which was greater in adult than aged mice. Vaccinated adult mice were better protected than aged mice after challenge with 2009 H1N1 virus, experiencing less morbidity and having lower pulmonary virus titers. The age-associated decline in immunity and protection was consistently greater among females than males, with the reduction in immunity and protection for aged as compared with adult females often being the sole comparison driving the overall age-associated significant differences. The age-associated reduction in stalk-based immunity in females was not, however, associated with changes in estradiol. To determine if the better antibodies in adults could be utilized to protect aged mice, serum was passively transferred from vaccinated adult mice into naïve sex-matched aged mice. Even with transferred serum from young adult mice, aged females still suffered greater morbidity than aged males. These data suggest there are sex-dependent effects of aging on cHA-based universal influenza virus vaccine-induced immunity that cannot be reversed through transfer of serum from young animals. The lack of consideration of sex-specific effects of aging on immunity could hinder efforts toward universal vaccines.
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Vírus da Influenza A Subtipo H1N1 , Vacinas contra Influenza , Influenza Humana , Infecções por Orthomyxoviridae , Fatores Etários , Animais , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Modelos Animais de Doenças , Feminino , Glicoproteínas de Hemaglutininação de Vírus da Influenza , Hemaglutininas , Humanos , Vírus da Influenza A Subtipo H1N1/imunologia , Vacinas contra Influenza/imunologia , Influenza Humana/imunologia , Influenza Humana/prevenção & controle , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Infecções por Orthomyxoviridae/imunologia , Infecções por Orthomyxoviridae/prevenção & controle , Fatores SexuaisRESUMO
BACKGROUND: Accurately measuring the risk of pressure injury remains the most important step for effective prevention and intervention. Relative contributions of risk factors for the incidence of pressure injury in adult critical care patients are not well understood. OBJECTIVE: To develop and validate a model to identify risk factors associated with hospital-acquired pressure injuries among adult critical care patients. METHODS: This retrospective cohort study included 23 806 adult patients (28 480 encounters) with an intensive care unit stay at an academic quaternary care center. Patient encounters were randomly split (7:3) into training and validation sets. The training set was used to develop a multivariable logistic regression model using the least absolute shrinkage and selection operator method. The model's performance was evaluated with the validation set. RESULTS: Independent risk factors identified by logistic regression were length of hospital stay, preexisting diabetes, preexisting renal failure, maximum arterial carbon dioxide pressure, minimum arterial oxygen pressure, hypotension, gastrointestinal bleeding, cellulitis, and minimum Braden Scale score of 14 or less. On validation, the model differentiated between patients with and without pressure injury, with area under the receiver operating characteristic curve of 0.85, and performed better than a model with Braden Scale score alone (P < .001). CONCLUSIONS: A model that identified risk factors for hospital-acquired pressure injury among adult critical care patients was developed and validated using a large data set of clinical variables. This model may aid in selecting high-risk patients for focused interventions to prevent formation of hospital-acquired pressure injuries.
Assuntos
Unidades de Terapia Intensiva , Úlcera por Pressão , Adulto , Cuidados Críticos , Hospitais , Humanos , Úlcera por Pressão/epidemiologia , Úlcera por Pressão/etiologia , Úlcera por Pressão/prevenção & controle , Estudos Retrospectivos , Fatores de RiscoRESUMO
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a global health problem. Although the respiratory system is the main impaired organ, conjunctivitis is one of its common findings. However, it is not yet understood if SARS-CoV-2 can infect the eye and if the ocular surface can be a potential route of SARS-CoV-2 transmissions. Our review focuses on the viral entry mechanisms to give a better understanding of the interaction between SARS-CoV-2 and the eye. We highlighted findings that give evidence for multiple potential receptors of SARS-CoV-2 on the ocular surface. Additionally, we focused on data concerning the detection of viral RNA and its spike protein in the various ocular tissues from patients. However, the expression level seemed to be relatively low compared to the respiratory tissues as a result of a unique environment surrounding the ocular surface and the innate immune response of SARS-CoV-2. Nevertheless, our review suggests the ocular surface as a potential route for SARS-CoV-2 transmission, and as a result of this study we strongly recommend the protection of the eyes for ophthalmologists and patients at risk.
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COVID-19/prevenção & controle , COVID-19/transmissão , Olho/virologia , SARS-CoV-2/fisiologia , Internalização do Vírus , COVID-19/metabolismo , COVID-19/patologia , Olho/metabolismo , Olho/patologia , Interações Hospedeiro-Patógeno , HumanosRESUMO
Obesity is a multifactorial condition with predominantly genetic and environmental causes and is an emerging risk factor for male infertility/subfertility. Epigenetic mechanisms are vulnerable to genetic and environmental changes. Our earlier studies have shown differential effects of genetically inherited (GIO) - and diet-induced- obesity (DIO) on DNA methylation in male germline. Contrary to DNA methylation is DNA demethylation, which also regulates the gene expression by activating transcription. The present study aimed to delineate the effects of obesity on the DNA demethylation pathway using two rat models: GIO (WNIN/Ob) and DIO (high-fat diet). We observed differential alterations in enzymes involved in DNA demethylation by oxidation (Tet1-3) pathway in testis in both groups. An increase in Tets in DIO group and a decrease in GIO group were noted. Analysis of oxidation pathway intermediates (5-hmC, 5-fC, and 5-caC) did not show any effect on testis in DIO group but an increase in 5-hmC and decrease in 5-caC levels in GIO group was observed. Analysis of transcript levels of enzymes related to deamination pathway in testis showed an increase (Gadd45a, Aicda, and Tdg) in DIO group and a decrease (Gadd45a, Aicda, and Tdg) in GIO group. Also, 5-hmC levels were differentially altered in the spermatozoa of both groups without any changes in Tet enzyme levels. These findings highlight differences in effects of GIO and DIO on DNA demethylation mechanisms in male germline, which could be due to differences in endocrine and metabolic profile as well as white fat distribution observed earlier in two groups.
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DNA/metabolismo , Dieta Hiperlipídica/efeitos adversos , Obesidade/induzido quimicamente , Obesidade/genética , Animais , Restrição Calórica , Desmetilação do DNA , Regulação da Expressão Gênica/efeitos dos fármacos , Masculino , Mutação , Ratos , Ratos WistarRESUMO
Over the past century, we have witnessed an increase in life-expectancy due to public health measures; however, we have also seen an increase in susceptibility to chronic disease and frailty. Microbiome dysfunction may be linked to many of the conditions that increase in prevalence with age, including type 2 diabetes, cardiovascular disease, Alzheimer's disease, and cancer, suggesting the need for further research on these connections. Moreover, because both non-modifiable (e.g., age, sex, genetics) and environmental (e.g., diet, infection) factors can influence the microbiome, there are vast opportunities for the use of interventions related to the microbiome to promote lifespan and healthspan in aging populations. To understand the mechanisms mediating many of the interventions discussed in this review, we also provide an overview of the gut microbiome's relationships with the immune system, aging, and the brain. Importantly, we explore how inflammageing (low-grade chronic inflammation that often develops with age), systemic inflammation, and senescent cells may arise from and relate to the gut microbiome. Furthermore, we explore in detail the complex gut-brain axis and the evidence surrounding how gut dysbiosis may be implicated in several age-associated neurodegenerative diseases. We also examine current research on potential interventions for healthspan and lifespan as they relate to the changes taking place in the microbiome during aging; and we begin to explore how the reduction in senescent cells and senescence-associated secretory phenotype (SASP) interplay with the microbiome during the aging process and highlight avenues for further research in this area.
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Optimal functioning of Sertoli cells is crucial for spermatogenesis which is under tight regulation of sex hormones, estrogen and androgen. Adult rat Sertoli cells expresses estrogen receptor beta (ERß) and androgen receptor (AR), both of which regulate gene transcription by binding to the DNA. The present study is aimed to acquire a genome-wide map of estrogen- and androgen-regulated genes in adult Sertoli cells. ChIP-Seq was performed for ERß and AR in Sertoli cells under physiological conditions. 30,859 peaks in ERß and 9,594 peaks in AR were identified with a fold enrichment >2 fold. Pathway analysis for the genes revealed metabolic pathways to be significantly enriched. Since Sertoli cells have supportive functions and provide energy substrates to germ cells during spermatogenesis, significantly enriched metabolic pathways were explored further. Peaks of the genes involved in lipid metabolism, like fatty acid, glyceride, leucine, and sphingosine metabolism were validated. Motif analysis confirmed the presence of estrogen- and androgen-response elements (EREs and AREs). Moreover, transcript levels of enzymes involved in the lipid metabolic pathways were significantly altered in cultured Sertoli cells treated with estrogen and androgen receptor agonists, demonstrating functional significance of these binding sites. This study elucidates a mechanism by which sex hormones regulate lipid metabolism in Sertoli cells by transcriptionally controlling the expression of these genes, thereby shedding light on the roles of these hormones in male fertility.
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Androgênios/farmacologia , Estrogênios/farmacologia , Estudo de Associação Genômica Ampla/métodos , Metabolismo dos Lipídeos , Receptores Androgênicos/metabolismo , Receptores de Estrogênio/metabolismo , Células de Sertoli/metabolismo , Animais , Sítios de Ligação , Regulação da Expressão Gênica , Genoma , Masculino , Ligação Proteica , Ratos , Ratos Sprague-Dawley , Receptores Androgênicos/genética , Receptores de Estrogênio/genética , Células de Sertoli/efeitos dos fármacosRESUMO
Cellular senescence is a stress or damage response that causes a permanent proliferative arrest and secretion of numerous factors with potent biological activities. This senescence-associated secretory phenotype (SASP) has been characterized largely for secreted proteins that participate in embryogenesis, wound healing, inflammation, and many age-related pathologies. By contrast, lipid components of the SASP are understudied. We show that senescent cells activate the biosynthesis of several oxylipins that promote segments of the SASP and reinforce the proliferative arrest. Notably, senescent cells synthesize and accumulate an unstudied intracellular prostaglandin, 1a,1b-dihomo-15-deoxy-delta-12,14-prostaglandin J2. Released 15-deoxy-delta-12,14-prostaglandin J2 is a biomarker of senolysis in culture and in vivo. This and other prostaglandin D2-related lipids promote the senescence arrest and SASP by activating RAS signaling. These data identify an important aspect of cellular senescence and a method to detect senolysis.
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Oxilipinas/metabolismo , Fenótipo Secretor Associado à Senescência , Senoterapia/metabolismo , Animais , Biomarcadores/metabolismo , Linhagem Celular , Humanos , Camundongos , Camundongos Endogâmicos C57BLRESUMO
BACKGROUND: Paternal obesity has been associated with reduced live birth rates. It could lead to inheritance of metabolic disturbances to the offspring through epigenetic mechanisms. However, obesity is a multifactorial disorder with genetic or environmental causes. Earlier we had demonstrated differential effects of high-fat diet-induced obesity (DIO) and genetically inherited obesity (GIO) on metabolic, hormonal profile, male fertility, and spermatogenesis using two rat models. The present study aimed to understand the effect of DIO and GIO on DNA methylation in male germline, and its subsequent effects on the resorbed (post-implantation embryo loss) and normal embryos. First, we assessed the DNA methylation enzymatic machinery in the testis by Real-Time PCR, followed global DNA methylation levels in spermatozoa and testicular cells by ELISA and flow cytometry, respectively. Further, we performed Methylation Sequencing in spermatozoa for both the groups. Sequencing data in spermatozoa from both the groups were validated using Pyrosequencing. Expression of the differentially methylated genes was assessed in the resorbed and normal embryos sired by the DIO group using Real-Time PCR for functional validation. RESULTS: We noted a significant decrease in Dnmt transcript and global DNA methylation levels in the DIO group and an increase in the GIO group. Sequencing analysis showed 16,966 and 9113 differentially methylated regions in the spermatozoa of the DIO and GIO groups, respectively. Upon pathway analysis, we observed genes enriched in pathways involved in embryo growth and development namely Wnt, Hedgehog, TGF-beta, and Notch in spermatozoa for both the groups, the methylation status of which partially correlated with the gene expression pattern in resorbed and normal embryos sired by the DIO group. CONCLUSION: Our study reports the mechanism by which diet-induced and genetically inherited obesity causes differential effects on the DNA methylation in the male germline that could be due to a difference in the white adipose tissue accumulation. These differences could either lead to embryo loss or transmit obesity-related traits to the offspring in adult life.
Assuntos
Dieta Hiperlipídica/efeitos adversos , Perda do Embrião/genética , Células Germinativas/metabolismo , Hereditariedade/genética , Obesidade/genética , Tecido Adiposo Branco/metabolismo , Animais , Estudos de Casos e Controles , Metilação de DNA , Perda do Embrião/metabolismo , Desenvolvimento Embrionário/genética , Epigênese Genética , Expressão Gênica , Masculino , Modelos Animais , Obesidade/metabolismo , Ratos , Ratos Wistar , Espermatogênese/genética , Espermatozoides/metabolismo , Testículo/enzimologiaRESUMO
Obesity is emerging as a potential risk factor for male infertility. It is a multifactorial disorder with primarily genetic and/or environmental factors. Our earlier studies have shown differential effects of genetically inherited-and high fat diet induced-obesity on hormones, fertility and spermatogenesis in adult male rats. In the present study, we assessed the effect of high fat diet induced - and genetically inherited - obesity on the underlying molecular mechanisms affecting spermatogenesis. The expression of hormone receptors, cytokines and markers of oxidative stress as well as cell cycle mediators were affected in both the obese groups, however, the changes were different in the two groups. This could be due to difference in fat distribution between the two types of obese groups. Altered expression of hormone receptors, cytokines, cell cycle mediators and differential effects on oxidative stress could be the plausible reason for differential changes in germ cell population in both the groups.
Assuntos
Citocinas/metabolismo , Dieta Hiperlipídica/efeitos adversos , Obesidade/induzido quimicamente , Obesidade/genética , Transdução de Sinais/efeitos dos fármacos , Testículo/citologia , Animais , Citocinas/genética , Regulação da Expressão Gênica , Predisposição Genética para Doença , Masculino , Estresse Oxidativo , Ratos , Ratos WistarRESUMO
Obesity is a multifactorial disorder with predominantly genetic and/or environmental causes. Our aim was to delineate effects of genetically inherited and high-fat diet-induced obesity on fertility and spermatogenesis using two Wistar rat models: genetically inherited obese (GIO) WNIN/Ob rats and diet-induced obese (DIO) rats, which received a high-fat diet. The terminal body weights were similar in both groups, but there was a significant difference in metabolic and hormone profiles between the groups. Fertility assessment revealed a significant decrease in the litter size due to increased pre- and postimplantation loss in the DIO group, whereas the rats in the GIO group were infertile due to lack of libido. Significantly decreased sperm counts were observed in the GIO group compared with the DIO group. Enumeration of testicular cells on the basis of ploidy and cell type-specific expression markers, to study the effect of obesity on spermatogenesis, demonstrated that the GIO and DIO states affected mitosis: spermatogonia and S-phase population were increased. However, distinctive effects were observed on meiosis and spermiogenesis in both the groups. Differential effects of GIO and DIO on fertility and spermatogenesis could be due to the significant difference in white adipose tissue accumulation between the groups and not due to high body weights. The differential effects of obesity suggest male obesity-induced infertility observed in humans could be a combination of genetic and environmental factors.