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Sirtuin 2 (SIRT2) regulates the maintenance of genome integrity by targeting pathways of DNA damage response and homologous recombination repair. However, whether and how SIRT2 promotes base excision repair (BER) remain to be determined. Here, we found that independent of its catalytic activity SIRT2 interacted with the critical glycosylase OGG1 to promote OGG1 recruitment to its own promoter upon oxidative stress, thereby enhancing OGG1 promoter activity and increasing BER efficiency. Further studies revealed that SIRT2 was phosphorylated on S46 and S53 by ATM/ATR upon oxidative stress, and SIRT2 phosphorylation enhanced the SIRT2-OGG1 interaction and mediated the stimulatory effect of SIRT2 on OGG1 promoter activity. We also characterized 37 cancer-derived SIRT2 mutants and found that 5 exhibited the loss of the stimulatory effects on OGG1 transcription. Together, our data reveal that SIRT2 acts as a tumor suppressor by promoting OGG1 transcription and increasing BER efficiency in an ATM/ATR-dependent manner.
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Proteínas Mutadas de Ataxia Telangiectasia , DNA Glicosilases , Reparo do DNA , Sirtuína 2 , Proteínas Mutadas de Ataxia Telangiectasia/metabolismo , Proteínas Mutadas de Ataxia Telangiectasia/genética , Humanos , Sirtuína 2/metabolismo , Sirtuína 2/genética , DNA Glicosilases/metabolismo , DNA Glicosilases/genética , Fosforilação , Regiões Promotoras Genéticas , Estresse Oxidativo , Ativação Transcricional , Células HEK293 , Dano ao DNA , Transcrição Gênica , Linhagem Celular Tumoral , Reparo por ExcisãoRESUMO
Patients with Hutchinson-Gilford progeria syndrome (HGPS) present with a number of premature aging phenotypes, including DNA damage accumulation, and many of them die of cardiovascular complications. Although vascular pathologies have been reported, whether HGPS patients exhibit cardiac dysfunction and its underlying mechanism is unclear, rendering limited options for treating HGPS-related cardiomyopathy. In this study, we reported a cardiac atrophy phenotype in the LmnaG609G/G609G mice (hereafter, HGPS mice). Using a GFP-based reporter system, we demonstrated that the efficiency of nonhomologous end joining (NHEJ) declined by 50% in HGPS cardiomyocytes in vivo, due to the attenuated interaction between γH2AX and Progerin, the causative factor of HGPS. As a result, genomic instability in cardiomyocytes led to an increase of CHK2 protein level, promoting the LKB1-AMPKα interaction and AMPKα phosphorylation, which further led to the activation of FOXO3A-mediated transcription of atrophy-related genes. Moreover, inhibiting AMPK enlarged cardiomyocyte sizes both in vitro and in vivo. Most importantly, our proof-of-concept study indicated that isoproterenol treatment significantly reduced AMPKα and FOXO3A phosphorylation in the heart, attenuated the atrophy phenotype, and extended the mean lifespan of HGPS mice by ~21%, implying that targeting cardiac atrophy may be an approach to HGPS treatment.
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Senilidade Prematura , Progéria , Humanos , Camundongos , Animais , Progéria/metabolismo , Coração , Dano ao DNA , Instabilidade Genômica , Proteínas Quinases Ativadas por AMP/genética , Lamina Tipo A/genética , Lamina Tipo A/metabolismoRESUMO
Aging is accompanied by a decreased DNA repair capacity, which might contribute to age-associated functional decline in multiple tissues. Disruption in hormone signaling, associated with reproductive organ dysfunction, is an early event of age-related tissue degeneration, but whether it impacts DNA repair in nonreproductive organs remains elusive. Using skin fibroblasts derived from healthy donors with a broad age range, we show here that the downregulation of expression of XRCC4, a factor involved in nonhomologous end-joining (NHEJ) repair, which is the dominant pathway to repair somatic double-strand breaks, is mediated through transcriptional mechanisms. We show that the androgen receptor (AR), whose expression is also reduced during aging, directly binds to and enhances the activity of the XRCC4 promoter, facilitating XRCC4 transcription and thus stabilizing the genome. We also demonstrate that dihydrotestosterone (DHT), a powerful AR agonist, restores XRCC4 expression and stabilizes the genome in different models of cellular aging. Moreover, DHT treatment reverses senescence-associated phenotypes, opening a potential avenue to aging interventions in the future.
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Androgênios , Reparo do DNA por Junção de Extremidades , Androgênios/metabolismo , Quebras de DNA de Cadeia Dupla , Reparo do DNA/genética , Transdução de Sinais , HumanosRESUMO
P2X7 receptor (P2X7R) plays an important role in modulating inflammation and fibrosis, but information is limited whether Zusanli (ST36) can inhibit inflammation and fibrosis by regulating P2X7R. Isoprenaline at 5 mg/kg was subcutaneously injected to wild-type and P2X7R knockout mice for 7 days, while treatment groups received electroacupuncture (EA) stimulation at ST36 for 7 sessions. Following 7-session treatment, Masson's trichrome staining was performed to assess the fibrosis. Morphology, electrocardiogram, and echocardiography were carried out to evaluate the cardiac function and structure. Western blotting, hematoxylin and eosin staining, immunohistochemistry, and biochemical analysis of inflammatory cytokine and transmission electron microscopy were carried out to characterize the effect of ST36 on inflammation. P2X7R was overexpressed in ISO-treated mice. EA at ST36, but not at non-points, reduced ISO-induced cardiac fibrosis, increases in HW/BW, R+S wave relative to mice in ISO groups. In addition, EA at ST36 downregulated ISO-upregulated P2X7R and NLRP3 in ventricle. Moreover, EA reduced cytokines of IL-1ß, IL-6, and IL-18 in serum, and inhibited foam cell gathering, inflammatory cell infiltration, and autophagy. However, EA at ST36 failed to attenuate the cardiac fibrosis and hypertrophy in P2X7R knockout mice. In conclusion, EA at ST36 attenuated ISO-induced fibrosis possibly via P2X7R.
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OBJECTIVE: Acetaminophen (APAP), an antipyretic and analgesic commonly used during pregnancy, has been recognized as a novel environmental contaminant. Preliminary evidence suggests that prenatal acetaminophen exposure (PAcE) could adversely affect offspring's gonadal and neurologic development, but there is no systematic investigation on the characteristics of APAP's fetal developmental toxicity. METHODS: Pregnant mice were treated with 100 or 400â¯mg/kgâd APAP in the second-trimester, or 400â¯mg/kgâd APAP in the second- or third-trimester, or different courses (single or multiple) of APAP, based on clinical regimen. The effects of PAcE on pregnancy outcomes, maternal/fetal blood phenotypes, and multi-organ morphological and functional development of fetal mice were analyzed. RESULTS: PAcE increased the incidence of adverse pregnancy outcomes and altered blood phenotypes including aminotransferases, lipids, and sex hormones in dams and fetuses. The expression of key functional genes in fetal organs indicated that PAcE inhibited hippocampal synaptic development, sex hormone synthesis, and osteogenic and chondrogenic development, but enhanced hepatic lipid synthesis and uptake, renal inflammatory hyperplasia, and adrenal steroid hormone synthesis. PAcE also induced marked pathological alterations in the fetal hippocampus, bone, kidney, and cartilage. The sensitivity rankings of fetal organs to PAcE might be hippocampus/bone > kidney > cartilage > liver > gonad > adrenal gland. Notably, PAcE-induced multi-organ developmental toxicity was more considerable under high-dose, second-trimester, and multi-course exposure and in male fetuses. CONCLUSION: This study confirmed PAcE-induced alterations in multi-organ development and function in fetal mice and elucidated its characteristics, which deepens the comprehensive understanding of APAP's developmental toxicity.
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Understanding differences in DNA double-strand break (DSB) repair between tumor and normal tissues would provide a rationale for developing DNA repair-targeted cancer therapy. Here, using knock-in mouse models for measuring the efficiency of two DSB repair pathways, homologous recombination (HR) and nonhomologous end-joining (NHEJ), we demonstrated that both pathways are up-regulated in hepatocellular carcinoma (HCC) compared with adjacent normal tissues due to altered expression of DNA repair factors, including PARP1 and DNA-PKcs. Surprisingly, inhibiting PARP1 with olaparib abrogated HR repair in HCC. Mechanistically, inhibiting PARP1 suppressed the clearance of nucleosomes at DNA damage sites by blocking the recruitment of ALC1 to DSB sites, thereby inhibiting RPA2 and RAD51 recruitment. Importantly, combining olaparib with NU7441, a DNA-PKcs inhibitor that blocks NHEJ in HCC, synergistically suppressed HCC growth in both mice and HCC patient-derived-xenograft models. Our results suggest the combined inhibition of both HR and NHEJ as a potential therapy for HCC.
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Carcinoma Hepatocelular/tratamento farmacológico , Cromonas/farmacologia , Morfolinas/farmacologia , Ftalazinas/farmacologia , Piperazinas/farmacologia , Animais , Quebras de DNA de Cadeia Dupla/efeitos dos fármacos , Dano ao DNA , Reparo do DNA por Junção de Extremidades/efeitos dos fármacos , Reparo do DNA/efeitos dos fármacos , Proteínas de Ligação a DNA/metabolismo , Quimioterapia Combinada/métodos , Técnicas de Introdução de Genes , Recombinação Homóloga , Humanos , Neoplasias Hepáticas/tratamento farmacológico , Camundongos , Camundongos Nus , Poli(ADP-Ribose) Polimerase-1/antagonistas & inibidores , Poli(ADP-Ribose) Polimerase-1/metabolismo , Reparo de DNA por Recombinação/efeitos dos fármacos , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Pyrrolizidine alkaloids (PAs) are a group of hepatic toxicant widely present in plants. Cytochrome P450 (CYP) 3A plays a key role in metabolic activation of PAs to generate electrophilic metabolites, which is the main cause of hepatotoxicity. We have previously demonstrated the sex difference in developmental toxicity and hepatotoxicity in fetal rats exposed to monocrotaline (MCT), a representative toxic PA. The aim of this study was to explore the underlying mechanism. 20â¯mg·kg-1·d-1 MCT was intragastrically given to pregnant Wistar rats from gestation day 9 to 20. CYP3As expression and pregnane X receptor (PXR) activation were specifically enhanced in female fetal liver. After MCT treatment, we also observed a significant increase of CYP3As expression in LO2 cells (high PXR level) or hPXR-transfected HepG2 cells (low PXR level). Employing hPXR and CYP3A4 dual-luciferase reporter gene assay, we confirmed the agonism effect of MCT on PXR-dependent transcriptional activity of CYP3A4. Agonism and antagonism of the androgen receptor (AR) either induced or blocked MCT-induced PXR activation, respectively. This study was the first report identifying that MCT served as PXR agonist to induce CYP3A expression. CYP3A induction may increase self-metabolic activation of MCT and subsequently lead to more severe hepatotoxicity in female fetus. While in male, during the intrauterine period, activated AR by testosterone secretion from developing testes represses MCT-induced PXR activation and CYP3A induction, which may partially protect male fetus from MCT-induced hepatotoxicity.
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Doença Hepática Induzida por Substâncias e Drogas , Citocromo P-450 CYP3A/genética , Fígado/efeitos dos fármacos , Monocrotalina/toxicidade , Receptor de Pregnano X/metabolismo , Animais , Linhagem Celular , Doença Hepática Induzida por Substâncias e Drogas/embriologia , Doença Hepática Induzida por Substâncias e Drogas/genética , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Feminino , Desenvolvimento Fetal/efeitos dos fármacos , Feto/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Fígado/metabolismo , Masculino , Troca Materno-Fetal , Gravidez , Ratos Wistar , Caracteres SexuaisRESUMO
SIRT6, a member of the SIRT deacetylase family, is responsible for deacetylation of histone H3 Nε-acetyl-lysines 9 (H3K9ac) and 56 (H3K56ac). As a tumor suppressor, SIRT6 has frequently been found to have low expression in various cancers. Here, we report the identification of MDL-800, a selective SIRT6 activator. MDL-800 increased the deacetylase activity of SIRT6 by up to 22-fold via binding to an allosteric site; this interaction led to a global decrease in H3K9ac and H3K56ac levels in human hepatocellular carcinoma (HCC) cells. Consequently, MDL-800 inhibited the proliferation of HCC cells via SIRT6-driven cell-cycle arrest and was effective in a tumor xenograft model. Together, these data demonstrate that pharmacological activation of SIRT6 is a potential therapeutic approach for the treatment of HCC. MDL-800 is a first-in-class small-molecule cellular SIRT6 activator that can be used to physiologically and pathologically investigate the roles of SIRT6 deacetylation.
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Antineoplásicos/farmacologia , Benzoatos/farmacologia , Ensaios de Triagem em Larga Escala/métodos , Sirtuínas/metabolismo , Compostos de Enxofre/farmacologia , Regulação Alostérica , Sítio Alostérico , Animais , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patologia , Linhagem Celular , Linhagem Celular Tumoral , Cristalografia por Raios X , Feminino , Humanos , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Camundongos Endogâmicos BALB C , Simulação de Dinâmica Molecular , Terapia de Alvo Molecular , Sirtuínas/química , Sirtuínas/genética , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
With the discovery of two-dimensional (2D) ferroelectric materials such as CuInP2S6andα-In2Se3, the ferroelectric field effect transistors (Fe-FETs) based on these materials have entered a rapid-development period. The metal/semiconductor contact is an unavoidable topic in the construction of devices. In this paper, heterostructuresα-In2Se3/metals (Pd, Pt, Cu, Ag and Au) are discussed. According to different stacking types, the structures and energy of 160 heterostructures are calculated and compared. Whenα-In2Se3contacts with the Pd, Pt and Cu, theα-In2Se3may transforms intoß-In2Se3. This phenomenon has hardly been mentioned or analyzed in previous reports. Contacting with the Au and Ag, theα-In2Se3maintains the original structure. The internal physical mechanism of phase transition is explained from the binding energy and the charge transfer. The paper provides sufficient theoretical support for research and development of the Fe-FETs based onα-In2Se3.
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OBJECTIVE: To observe the clinical efficacy of femtosecond laser-assisted cataract surgery (FLACS) for diabetic cataract (DC). METHODS: One hundred and seven cases of DC admitted between August 2018 and August 2021 were enrolled, and their clinical data were retrospectively analyzed. Of them, 53 cases treated with conventional phacoemulsification (Phaco) cataract surgery (CPS) were set as the control group (the Con) and 54 cases receiving FLACS were set as the observation group (the Obs). Clinical data such as effective phaco time (EPT), color doppler energy (CDE), best corrected visual acuity (BCVA), visual quality, corneal endothelial cell (CEC) count (CECC), and complication rate were compared and analyzed. Finally, multivariate Cox regression analysis was performed to analyze the prognostic factors based on the incidence of complications in DC patients. RESULTS: The Obs had significantly lower EPT and CDE compared to the Con, as well as markedly elevated BCVA and visual quality at one month after operation compared to the preoperative levels and the Con. The CECC of the Obs differed insignificantly from that before surgery and was higher versus the Con. Moreover, the incidence of postoperative complications (corneal edema, fibrin exudation, pigment dispersion, and posterior synechia of the iris) was lower in the Obs. Moreover, the treatment method was an independent prognostic factor affecting the prognosis of DC patients. CONCLUSIONS: The above analysis suggests the superior efficacy of FLACS to CPS for DC, as it can more significantly reduce EPT, CDE, CEC loss, and the incidence of postoperative complications with a positive effect on improving BCVA, visual quality, and patient prognosis.
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Introduction: Auricular acupressure (AA) has been widely utilized in the management of constipation, with several studies suggesting its efficacy in treating constipation patients. However, the safety and effectiveness of AA in constipation remain uncertain. Hence, the aim of this study was to assess the effectiveness and safety of AA for constipation. Methods and analysis: A total of eight electronic databases and three clinical trial registration platforms were searched from their inception to April 2023 for randomized controlled trials (RCTs) of AA for constipation. The included studies were appraised for quality using the Cochrane Collaboration's Risk of Bias Assessment tool. The quality of evidence was assessed by two independent reviewers employing the Grading of Recommendations Assessment, Development, and Evaluation System (GRADE) evaluation tool. Meta-analysis of data and assessment of publication bias were performed using RevMan 5.4 and STATA 13.0 software, respectively. Results: This review included 34 randomized controlled trials conducted between 2007 and 2023, involving 2,465 participants. The findings of the study indicate that overall, AA is significantly associated with improved CSBMs (MD = 1.22, 95% CI [0.68, 1.77], p < 0.0001, I2 = 0%), BSF (MD = 0.72, 95%CI: [0.15,1.28], p = 0.01, I2 = 82%), CAS (MD = -3.28, 95%CI: [-5.95, -0.60], p = 0.02, I2 = 80%), responder rate (RR = 1.27, 95%CI: [1.16, 1.38], p < 0.00001, I2 = 79%), cure rate (RR = 1.84, 95% CI [1.56, 2.15], p < 0.00001, I2 = 0%), and PAC-QOL (MD = -2.73, 95% CI: [-3.41, -2.04], p < 0.00001, I2 = 98%) compared to the control group. However, no difference in PAC-SYM (MD = -0.15, 95%CI: [-0.38,0.07], p = 0.19, I2 = 67%) was found between the two groups. Additionally, there was no significant difference in adverse events (RR = 0.53, 95% CI: [0.24, 1.21], p = 0.13, I2 = 38%). Conclusion: Based on the available evidence, auricular acupressure appears to be a potentially safe and effective intervention for managing constipation in adults. Nonetheless, the overall quality of evidence for the identified outcomes was assessed as low to very low, highlighting the need for additional high-quality randomized controlled trials to further validate these findings. Systematic Review Registration: https://www.crd.york.ac.uk/prospero, identifier CRD42023425033.
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Pyrrolizidine alkaloids (PAs) are a type of plant-derived environmental toxins, which pose a health hazard to human and livestock via contaminating soil, water, plants and food. In this study, we aimed to investigate the effect of lactational retrorsine (RTS, a typical toxic PA) exposure on breastmilk components and glucose-lipid metabolism of offspring rats. Dams were intragastrically administered with 5 mg/(kg·d) RTS during lactation. After metabolomic analyses, 114 differential constituents were identified in breastmilk between control and RTS groups, featured by reduction of lipids and lipid-like molecules, while presence of abundant RTS and its derivative in RTS-exposed milk. RTS exposure induced liver injury in pups, but the leakage of transaminases in serum recovered in their adulthood. Serum glucose levels were lower in pups but higher in male adult offspring from RTS group. RTS exposure also induced hypertriglyceridemia, hepatic steatosis and decreased glycogen content in both pups and adult offspring. Additionally, suppression of PPARα-FGF21 axis persisted in offspring liver after RTS exposure. These data indicated that inhibition of PPARα-FGF21 axis induced by milk deficient in lipid contents, together with hepatotoxic injury caused by RTS in breastmilk, may disrupt glucose and lipid metabolism of pups, and the persistent suppression of PPARα-FGF21 axis may program metabolic disorder of glucose and lipid in adult offspring.
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Leite , Alcaloides de Pirrolizidina , Feminino , Humanos , Ratos , Animais , Adulto , Leite/metabolismo , PPAR alfa/metabolismo , PPAR alfa/farmacologia , Lactação/metabolismo , Alcaloides de Pirrolizidina/toxicidade , Alcaloides de Pirrolizidina/metabolismo , Fígado/metabolismo , Homeostase , Glucose/metabolismo , Lipídeos , Exposição MaternaRESUMO
Background: The evidence for the effectiveness of electroacupuncture (EA) for post-stroke urinary incontinence (PSUI) patients remains unclear. Therefore, the purpose of this systematic review and meta-analysis was to assess the efficacy of EA for PSUI. Methods and analysis: Eight English and Chinese databases were searched from their inception until 1 August 2023 to collect randomized controlled trials (RCTs) that investigated the effect of EA on PSUI. Two reviewers independently selected studies that met the eligibility criteria, extracted the necessary data, and assessed the risk of bias for included studies using Cochrane Handbook version 5.1.0. Meta-analysis was performed using Review Manager software (version 5.4.1). Publication bias detection was conducted using STATA (version 16.0). Sequential analysis was performed using TSA 0.9.5.10 Beta. The Grading of Recommendations Assessment, Development, and Evaluation System (GRADE) was used for assessing the certainty of evidence. Results: We included 15 RCTs involving a total of 1,414 patients. The narrative analysis revealed that compared with sham EA, genuine EA exhibited greater efficacy in reducing occurrences of 24-h urinary incontinence while also enhancing maximum cystometric capacity (MCC). Moreover, this effect remained significant even during the 3-month follow-up period. Fourteen studies were encompassed within the quantitative analysis. In contrast to active interventions, EA did not yield an improvement in the responder rate (RR 1.53, 95% CI 0.61 to 3.80, p = 0.36). When compared with basic treatments, the combination of EA with them led to a reduction in 24-h urinary incontinence occurrences (MD -0.56, 95% CI -0.60 to -0.52, p < 0.00001), an improvement in MCC (MD 43.23, 95% CI 28.86 to 57.60, p < 0.00001), and a decrease in residual urine volume (RUV; MD -19.99, 95% CI -29.75 to -10.23, p < 0.0001). However, it did not lead to an increase in the responder rate (RR 1.39, 95% CI 0.88 to 2.20, p = 0.16). In comparison to basic treatments combined with active interventions, the amalgamation of EA and them led to an increase in the responder rate (RR 1.24, 95% CI 1.14 to 1.35, p < 0.00001), a reduction in 24-h urinary incontinence occurrences (MD -2.90, 95% CI -5.26 to -0.55, p = 0.02), a decrease in International Consultation on Incontinence Questionnaire-Short Form scores, and an improvement in both MCC (MD 42.11, 95% CI 23.26 to 60.96, p < 0.0001) and RUV (MD 42.11, 95% CI 23.26 to 60.96, p < 0.0001). Furthermore, all reported adverse effects associated with EA were mild. The trial sequential analysis suggested that a sufficient sample size was available to yield results. However, the level of evidence was predominantly assessed as low or very low. Conclusion: Electroacupuncture improved post-stroke urinary incontinence with no serious adverse effects. Caution is warranted due to methodological issues, and more high-quality studies are required to confirm its efficacy and safety.Systematic Review Registration:https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023449599, Identifier CRD42023449599.
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Poly(ADP-ribose) polymerase 1 (PARP1) is essential for the progression of several types of cancers. However, whether and how PARP1 is stabilized to promote genomic stability in triple-negative breast cancer (TNBC) remains unknown. Here, we demonstrated that the deubiquitinase USP15 interacts with and deubiquitinates PARP1 to promote its stability, thereby stimulating DNA repair, genomic stability and TNBC cell proliferation. Two PARP1 mutations found in individuals with breast cancer (E90K and S104R) enhanced the PARP1-USP15 interaction and suppressed PARP1 ubiquitination, thereby elevating the protein level of PARP1. Importantly, we found that estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2) inhibited USP15-mediated PARP1 stabilization through different mechanisms. ER bound to the USP15 promoter to suppress its expression, PR suppressed the deubiquitinase activity of USP15, and HER2 abrogated the PARP1-USP15 interaction. The specific absence of these three receptors in TNBC results in high PARP1 levels, leading to increases in base excision repair and female TNBC cell survival.
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Poli(ADP-Ribose) Polimerase-1 , Neoplasias de Mama Triplo Negativas , Proteases Específicas de Ubiquitina , Feminino , Humanos , Enzimas Desubiquitinantes/genética , Instabilidade Genômica , Poli(ADP-Ribose) Polimerase-1/genética , Receptores de Estrogênio/genética , Receptores de Progesterona/genética , Receptores de Progesterona/metabolismo , Neoplasias de Mama Triplo Negativas/genética , Neoplasias de Mama Triplo Negativas/metabolismo , Proteases Específicas de Ubiquitina/genéticaRESUMO
Farrerol, a natural flavanone, promotes homologous recombination (HR) repair to improve genome-editing efficiency, but the specific protein that farrerol directly targets to regulate HR repair and the underlying molecular mechanisms have not been determined. Here, we find that the deubiquitinase UCHL3 is the direct target of farrerol. Mechanistically, farrerol enhanced the deubiquitinase activity of UCHL3 to promote RAD51 deubiquitination, thereby improving HR repair. Importantly, we find that embryos of somatic cell nuclear transfer (SCNT) exhibited defective HR repair, increased genomic instability and aneuploidy, and that the farrerol treatment post nuclear transfer enhances HR repair, restores transcriptional and epigenetic network, and promotes SCNT embryo development. Ablating UCHL3 significantly attenuates farrerol-mediated stimulation in HR and SCNT embryo development. In summary, we identify farrerol as an activator of the deubiquitinase UCHL3, highlighted the importance of HR and epigenetic changes in SCNT reprogramming and provide a feasible method to promote SCNT efficiency.
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Reparo do DNA , Técnicas de Transferência Nuclear , Reprogramação Celular/genética , Enzimas Desubiquitinantes/genética , Embrião de Mamíferos , Desenvolvimento Embrionário/genética , Epigênese Genética , AnimaisRESUMO
Powdery mildew disease caused by Podosphaerapannosa is the most widespread disease in global cut-rose production, as well as a major disease in garden and pot roses. In this study, the powdery mildew resistance of different wild rose varieties was evaluated. Rose varieties with high resistance and high sensitivity were used for cytological observation and transcriptome and expression profile analyses to study changes at the morphological and molecular levels during the interaction between Rosa multiflora and P. pannosa. There were significant differences in powdery mildew resistance among three R. multiflora plants; R. multiflora '13' had high resistance, while R. multiflora '4' and '1' had high susceptibility. Cytological observations showed that in susceptible plants, 96 and 144 h after inoculation, hyphae were observed in infected leaves; hyphae infected the leaf tissue through the stoma of the lower epidermis, while papillae were formed on the upper epidermis of susceptible leaf tissue. Gene ontology enrichment analysis showed that the differentially expressed genes that were significantly enriched in biological process functions were related to the secondary metabolic process, the most significantly enriched cellular component function was cell wall, and the most significantly enriched molecular function was chitin binding. Changes in the transcript levels of important defense-related genes were analyzed. The results showed that chitinase may have played an important role in the interactions between resistant R. multiflora and P. pannosa. Jasmonic acid and ethylene (JA/ET) signaling pathways might be triggered in the interaction between susceptible R. multiflora and P. pannosa. In the resistant R. multiflora, the salicylic acid (SA) signaling pathway was induced earlier. Between susceptible plants and resistant plants, key phenylpropanoid pathway genes were induced and upregulated after P. pannosa inoculation, demonstrating that the phenylpropanoid pathway and secondary metabolites may play important and active roles in R. multiflora defense against powdery mildew infection.
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Ascomicetos , Rosa , Ascomicetos/metabolismo , Doenças das Plantas/genética , Rosa/genética , Ácido Salicílico/metabolismoRESUMO
This study aimed at determining the effect of prenatal ethanol exposure (PEE) on the expression and activity of cytochrome P450 (CYP) isozymes at different life stages of male rat offspring. Pregnant Wistar rats were administered with ethanol (4 g/kg/d) intragastrically from gestational day (GD) 9-20. Male offspring's gene and activity of CYP isozymes were analyzed on GD 20 (only expression), postnatal day (PD) 84 and 196. Using aniline as probe, we compared the enzyme kinetics of hepatic CYP2E1 between two groups. Expression of CYP isozymes was examined in rat primary hepatocytes and human hepatic cell lines treated with ethanol or/and glucocorticoid. Gene level of Cyp1a2, 2b1, 2d1, 2e1, 3a1 and aryl hydrocarbon receptor were increased in PEE group on GD 20 and PD 84 and Cyp2e1 still exhibited an increasing trend on PD 196 compared with the control. PEE inhibited CYP2D1 and 2E1 activities in male offspring on PD 84. CYP activities in two groups became the same level on PD 196. PEE induced an opposite change in gene and protein level of hepatic CYP2E1 before and after birth. In consistent with lower protein level, aniline metabolism in PEE was weaker in liver microsome. Both single and combined use of ethanol or/and glucocorticoid increased CYPs expression in vitro. In conclusion, PEE programmed a higher gene and lower protein level of CYPs in male offspring, which dwindled with age. Impairment of protein levels and enzyme activities of CYPs may affect individual metabolism of endogenous and exogenous substances in early adulthood.
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Sistema Enzimático do Citocromo P-450 , Fígado , Animais , Sistema Enzimático do Citocromo P-450/genética , Sistema Enzimático do Citocromo P-450/metabolismo , Etanol/toxicidade , Feminino , Fígado/metabolismo , Masculino , Gravidez , Isoformas de Proteínas/metabolismo , Isoformas de Proteínas/farmacologia , Ratos , Ratos WistarRESUMO
Understanding community assembly is a key issue in recognizing community succession and guiding the restoration of degraded ecosystems. Based on the stress-dominance hypothesis (SDH), along a gradient of increasing environmental stress, the relative importance of environmental filtering is supposed to be dominant but species interaction could be a minor process in assembling communities. However, this hypothesized model of the assembly-rule shift was equivocally supported by various studies. In this study, by examining riparian plant communities with the zonation distribution of species composition along a markedly contrast flooding-stress gradient, a general aim was to clarify whether assembly rules of the communities would be also sorted into the zonation pattern as expected by the SDH. Another aim was to identify how edaphic factors associate with the assembly processes. Firstly, we found that even under the distinct stress gradient, community assembly was not stratified into different rules as the SDH expected, but environmental filtering appeared as a dominant assembly process across the stress gradient. Secondly, although filtering holds as a dominant assembly rule, environmental filters were found different along the gradient. By disentangling the filters of edaphic attributes, we found that the filters significantly shifted from soil physical properties to chemical nutrients governing the filtering process along the gradient. This result revealed that, across the contrast gradient, the environmental deterministic process on assembly is so strong that the other assembly processes became weaker. By synthesizing our results, the SDH may not be applied even under the context of a contrast stress gradient, which suggests that environmental context may be a key in testing and applying the SDH. Finally, in guiding riparian restoration under strong stress, we suggest that soil physical structure rather than chemical nutrients shall be given a priority for consideration in rebuilding the degraded riparian communities.
Assuntos
Ecossistema , Solo , Inundações , Plantas , Estresse FisiológicoRESUMO
The prevalence of diabetes in children and adolescents has been rising gradually, which is relevant to adverse environment during development, especially prepartum. We aimed to explore the effects of prenatal dexamethasone exposure (PDE) on ß-cell function and glucose homeostasis in juvenile offspring rats. Pregnant Wistar rats were subcutaneously administered with dexamethasone [0.1, 0.2, 0.4mg/(kg.d)] from gestational day 9 to 20. PDE impaired glucose tolerance in the male offspring rather than the females. In male offspring, PDE impaired the development and function of ß-cells, accompanied with lower H3K9ac, H3K14ac and H3K27ac levels in the promoter region of angiotensin-converting enzyme 2 (ACE2) as well as suppressed ACE2 expression. Meanwhile, PDE increased expression of glucocorticoid receptor (GR) and histone deacetylase 3 (HDAC3) in fetal pancreas. Dexamethasone also inhibited ACE2 expression and insulin production in vitro. Recombinant expression of ACE2 restored insulin production inhibited by dexamethasone. In addition, dexamethasone activated GR and HDAC3, increased protein interaction of GR with HDAC3, and promoted the binding of GR-HDAC3 complex to ACE2 promoter region. Both RU486 and TSA abolished dexamethasone-induced decline of histone acetylation and ACE2 expression. In summary, suppression of ACE2 is involved in PDE induced ß-cell dysfunction and glucose intolerance in juvenile male offspring rats.