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Alveolar epithelial cell (AEC) senescence is implicated in the pathogenesis of pulmonary fibrosis (PF). However, the exact mechanism underlying AEC senescence during PF remains poorly understood. Here, we reported an unrecognized mechanism for AEC senescence during PF. We found that, in bleomycin (BLM)-induced PF mice, the expressions of isocitrate dehydrogenase 3α (Idh3α) and citrate carrier (CIC) were significantly down-regulated in the lungs, which could result in mitochondria citrate (citratemt) accumulation in our previous study. Notably, the down-regulation of Idh3α and CIC was related to senescence. The mice with AECs-specific Idh3α and CIC deficiency by adenoviral vector exhibited spontaneous PF and senescence in the lungs. In vitro, co-inhibition of Idh3α and CIC with shRNA or inhibitors triggered the senescence of AECs, indicating that accumulated citratemt triggers AEC senescence. Mechanistically, citratemt accumulation impaired the mitochondrial biogenesis of AECs. In addition, the senescence-associated secretory phenotype from senescent AECs induced by citratemt accumulation activated the proliferation and transdifferentiation of NIH3T3 fibroblasts into myofibroblasts. In conclusion, we show that citratemt accumulation would be a novel target for protection against PF that involves senescence.
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Alveolar epithelial cell (AEC) senescence is a key driver of a variety of chronic lung diseases. It remains a challenge how to alleviate AEC senescence and mitigate disease progression. Our study identified a critical role of epoxyeicosatrienoic acids (EETs), downstream metabolites of arachidonic acid (ARA) by cytochrome p450 (CYP), in alleviating AEC senescence. In vitro, we found that 14,15-EET content was significantly decreased in senescent AECs. Exogenous EETs supplementation, overexpression of CYP2J2, or inhibition of EETs degrading enzyme soluble epoxide hydrolase (sEH) to increase EETs alleviated AECs' senescence. Mechanistically, 14,15-EET promoted the expression of Trim25 to ubiquitinate and degrade Keap1 and promoted Nrf2 to enter the nucleus to exert an anti-oxidant effect, thereby inhibiting endoplasmic reticulum stress (ERS) and alleviating AEC senescence. Furthermore, in D-galactose (D-gal)-induced premature aging mouse model, inhibiting the degradation of EETs by Trifluoromethoxyphenyl propionylpiperidin urea (TPPU, an inhibitor of sEH) significantly inhibited the protein expression of p16, p21, and γH2AX. Meanwhile, TPPU reduced the degree of age-related pulmonary fibrosis in mice. Our study has confirmed that EETs are novel anti-senescence substances for AECs, providing new targets for the treatment of chronic lung diseases.
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Células Epiteliais Alveolares , Senescência Celular , Eicosanoides , Estresse do Retículo Endoplasmático , Fator 2 Relacionado a NF-E2 , Animais , Camundongos , Células Epiteliais Alveolares/efeitos dos fármacos , Células Epiteliais Alveolares/fisiologia , Eicosanoides/farmacologia , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Proteína 1 Associada a ECH Semelhante a Kelch , Fator 2 Relacionado a NF-E2/genética , Fibrose Pulmonar , Senescência Celular/efeitos dos fármacosRESUMO
BACKGROUND: Necroptosis of macrophages is a necessary element in reinforcing intrapulmonary inflammation during acute lung injury (ALI). However, the molecular mechanism that sparks macrophage necroptosis is still unclear. Triggering receptor expressed on myeloid cells-1 (TREM-1) is a pattern recognition receptor expressed broadly on monocytes/macrophages. The influence of TREM-1 on the destiny of macrophages in ALI requires further investigation. METHODS: TREM-1 decoy receptor LR12 was used to evaluate whether the TREM-1 activation induced necroptosis of macrophages in lipopolysaccharide (LPS)-induced ALI in mice. Then we used an agonist anti-TREM-1 Ab (Mab1187) to activate TREM-1 in vitro. Macrophages were treated with GSK872 (a RIPK3 inhibitor), Mdivi-1 (a DRP1 inhibitor), or Rapamycin (an mTOR inhibitor) to investigate whether TREM-1 could induce necroptosis in macrophages, and the mechanism of this process. RESULTS: We first observed that the blockade of TREM-1 attenuated alveolar macrophage (AlvMs) necroptosis in mice with LPS-induced ALI. In vitro, TREM-1 activation induced necroptosis of macrophages. mTOR has been previously linked to macrophage polarization and migration. We discovered that mTOR had a previously unrecognized function in modulating TREM-1-mediated mitochondrial fission, mitophagy, and necroptosis. Moreover, TREM-1 activation promoted DRP1Ser616 phosphorylation through mTOR signaling, which in turn caused surplus mitochondrial fission-mediated necroptosis of macrophages, consequently exacerbating ALI. CONCLUSION: In this study, we reported that TREM-1 acted as a necroptotic stimulus of AlvMs, fueling inflammation and aggravating ALI. We also provided compelling evidence suggesting that mTOR-dependent mitochondrial fission is the underpinning of TREM-1-triggered necroptosis and inflammation. Therefore, regulation of necroptosis by targeting TREM-1 may provide a new therapeutic target for ALI in the future.
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Lesão Pulmonar Aguda , Lipopolissacarídeos , Animais , Camundongos , Receptor Gatilho 1 Expresso em Células Mieloides , Lipopolissacarídeos/farmacologia , Dinâmica Mitocondrial , Necroptose , Serina-Treonina Quinases TOR , Macrófagos , InflamaçãoRESUMO
Background: Tai Chi Chuan (TCC) is a physical activity modality that originated in China and is now widely popular around the world. Although there are a series of articles reporting that TCC can improve balance and other functional symptoms in a variety of populations, including the elderly, patients with stroke, and patients with Parkinson's disease, its efficiency has not been scientifically and methodically evaluated in subjects with functional ankle instability (FAI). Moreover, there is no literature directly comparing TCC and conventional balance training (CBT) interventions for FAI. The objective of this study is to investigate the comparative effects of TCC intervention and CBT protocols in improving postural balance and subjective instability feelings in patients with FAI. Methods: This study will be a single-center, parallel group, randomized controlled trial. Sixty-eight patients with FAI will be included and randomly assigned in a 1:1 ratio to either an intervention group (n =34) or a control group (n = 34). The participants in the intervention group will complete 12 weeks of TCC intervention (40 min/time, 3 times/week for 12 weeks) on the basis of health education treatment. The control group will receive health education and 36 CBT sessions during a 12-week period. Outcome measures include postural stability and self-reported feelings of instability at baseline, after the end of the intervention, and 3-month follow-up. The postural stability assessment of patients with FAI will be detected by performing static and dynamic postural tests, which will be carried out through a specific balance platform (TecnoBody ProKin). Self-reported feelings of instability will be assessed by Cumberland Ankle Instability Tool (CAIT), American Orthopedics Foot and Ankle Society's Ankle-Hindfoot Evaluation Scale (AOFAS-AHES), and the MOS item Short Form Health Survey (SF-36). Discussion: This trial will demonstrate whether a 12-week TCC intervention positively affects postural stability and self-reported outcomes in patients with FAI. At the same time, the superiority of its clinical efficacy will also be compared with that of CBT. This study may also help to redefine the value of traditional Chinese exercises in the treatment of chronic ankle instability. Clinical trial registration: Chinese Clinical Trial Registry: ChiCTR2100041790. Registration date: 22 March 2021. http://www.chictr.org.cn/edit.aspx?pid=119501&htm=4.
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Sexually dimorphic plumage coloration is widespread in birds in which the male plumage is brighter than the female. This phenomenon is related to the environmental constraints on sexual selection or intraspecific competition between males and females in birds. The physiological factors and genetic regulation mechanism affecting the color of sexual dimorphism plumages in birds have always attracted significant attention in research. Understanding the diversity of sexually dimorphic traits provides insights into the mating strategies of the sexes and their behavior, ecology, and evolution. Interestingly, the ASIP, MC1R, TYRP1, and BCO2 genes have been identified to play a potential role in the coloration of melanin and carotenoids in bird sexual dimorphism plumages, either by controlling the rate and type of melanin or carotene synthesis or degradation by exerting an effect on the pigment biosynthetic pathway. In this review, we systematically summarize the biological significance, the direct causes (chemical and physical color), and the influence of sex hormones in sexually dimorphic plumage coloration. We also investigate the molecular mechanism underlying the roles of some genes on sexual dimorphism coloration, thereby providing a reference for in-depth understanding on the formation mechanism(s) of sexual dimorphic coloration in birds.
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Plumas , Caracteres Sexuais , Animais , Aves/genética , Aves/metabolismo , Cor , Plumas/metabolismo , Feminino , Masculino , Melaninas/genética , Pigmentação/genéticaRESUMO
In poultry, feed restriction is common feeding management to limit poultry nutrients intake so that poultry only intake the essential energy, meeting the basic need of growth and development. Our study investigated whether feeding restriction affects the diversity of the intestinal microbiota of growing breeding ducks. In this research, the 60-120-day-old ducks were raised in restricted and free-feeding groups. After slaughtering, the carcass traits and the cecal contents were collected for 16S rRNA sequencing analysis. After feeding restriction, the growth rate of ducks was limited, the weight and rate of abdominal fat decreased, and the rate of chest and leg muscles increased. In addition, feeding restriction can also change the diversity of intestinal microorganisms in breeding ducks, such as the increase of Firmicutes abundance and the decrease of Bacteroidetes abundance. After analyzing of correlation, significant correlations between gut microbiota and carcass phenotypes were found. The results indicated that gut microbiota might be involved in the life activities associated with phenotypic changes. This study proved the effect of feeding methods on the intestinal microbiota of ducks, providing a theoretical basis of the microbial angle for raising ducks in a feeding-restricted period.
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Microbioma Gastrointestinal , Microbiota , Ração Animal/análise , Animais , Patos , Intestinos , RNA Ribossômico 16S/genéticaRESUMO
Ahead of Print article withdrawn by publisher.
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Vascular smooth muscle cell (VSMC) proliferation is a primary pathological event in the development of atherosclerosis (AS), and the presence of homocysteine (Hcy) acts as an independent risk factor for AS. However, the underlying mechanisms remain to be elucidated. Phosphatase and tensin homologue on chromosome 10 (PTEN), is endogenously expressed in VSMCs and induces multiple signaling networks involved in cell proliferation, survival and inflammation, however, the specific role of PTEN is still unknown. The present study detected the proliferation ratio of VSMCs following treatment with Hcy and Resveratrol (RSV). In the 100 µM Hcy group, the proliferation ratio increased, and treatment with RSV decreased the proliferation ratio induced by Hcy. Reverse transcriptionquantitative polymerase chain reaction and western blotting were used to analyze PTEN expression, RSV treatment was associated with decreased PTEN expression levels in VSMCs. PTEN levels were decreased in Hcy treated cells, and the proliferation ratio of VSMCs were increased following treated with Hcy. To study the mechanism of regulation of PTEN by Hcy, the present study detected PTEN methylation levels in VSMCs, and PTEN DNA methylation levels were demonstrated to be increased in the 100 µM Hcy group, whereas treatment with RSV decreased the methylation status. DNA methyltransferase 1 is important role in the regulation of PTEN methylation. Overall, Hcy impacts the methylation status of PTEN, which is involved in cell proliferation, and induces the proliferation of VSMCs. This effect is alleviated by treatment with RSV, which exhibits an antagonistic mechanism against Hcy.
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Metilação de DNA/genética , Regulação da Expressão Gênica/efeitos dos fármacos , Homocisteína/metabolismo , Músculo Liso Vascular/citologia , Miócitos de Músculo Liso/metabolismo , PTEN Fosfo-Hidrolase/genética , Estilbenos/farmacologia , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Homocisteína/farmacologia , Miócitos de Músculo Liso/efeitos dos fármacos , PTEN Fosfo-Hidrolase/metabolismo , ResveratrolRESUMO
Endothelial progenitor cells (EPCs) contribute to neovasculogenesis and reendothelialization of damaged blood vessels to maintain the endothelium. Dysfunction of EPCs is implicated in the pathogenesis of vascular injury induced by homocysteine (Hcy). We aimed to investigate the role of Cyclin A in Hcy-induced EPCs dysfunction and explore its molecular mechanism. In this study, by treatment of EPCs with Hcy, we found that the expression of Cyclin A mRNA and protein were significantly downregulated in a dose-dependent manner. Knockdown of Cyclin A prominently reduced proliferation of EPCs, while over-expression of Cyclin A significantly promoted the cell proliferation, suggesting that Hcy inhibits EPCs proliferation through downregulation of Cyclin A expression. In addition, epigenetic study also demonstrated that Hcy induces DNA hypomethylation of the Cyclin A promoter in EPCs through downregulated expression of DNMT1. Moreover, we found that Hcy treatment of EPCs leads to increased SAM, SAH and MeCP2, while the ratio of SAM/SAH and MBD expression decrease. In summary, our results indicate that Hcy inhibits Cyclin A expression through hypomethylation of Cyclin A and thereby suppress EPCs proliferation. These findings demonstrate a novel mechanism of DNA methylation mediated by DNMT1 in prevention of Hcy associated cardiovascular disease.
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Proliferação de Células/fisiologia , Ciclina A/metabolismo , DNA (Citosina-5-)-Metiltransferase 1/metabolismo , Metilação de DNA/fisiologia , Células Progenitoras Endoteliais/metabolismo , Homocisteína/metabolismo , Animais , Células Cultivadas , Regulação para Baixo/fisiologia , Epigênese Genética/fisiologia , Humanos , Regiões Promotoras Genéticas/fisiologia , RatosRESUMO
Atherosclerosis (AS) is a progressive disease of multifactorial origin, which occurs in response to endothelial injury. Increased homocysteine (Hcy) is considered a major cause of endothelial dysfunction, oxidative stress and DNA methylation; however, the mechanisms remain to be fully elucidated. The aim of the present study was to investigate whether Hcy causes injury to endothelial cells (ECs) by the effect of lectinlike oxidizedlow density lipoprotein receptor1 (LOX1) DNA methylation through tolllike receptor 4(TLR4)/nuclear factor (NF)κB/DNA methyltransferase (DNMT)1. The ECs were treated with different concentrations of Hcy, and it was found that Hcy promoted the expression of TLR4, leading to EC injury. The effect of oxidative stress was analyzed by measuring superoxide dismutase, malondialdehyde and hydrogen peroxide in the ECs. In addition, the association between NFκB and DNMT1 was examined by treatment of the ECs with pyrrolidine dithiocarbamate (PDTC). The results suggested that Hcy induced LOX1 DNA hypomethyaltion to promote the expression levels of LOX1. Taken together, Hcy injured the ECs through the effect of methylation and transsulfuration metabolism of LOX1 through TLR4/NFκB/DNMT1. Following injury to the ECs, lipids, particularly oxLDL, accumulated in the subendothelial layer to promote the formation of AS.
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DNA (Citosina-5-)-Metiltransferase 1/metabolismo , Metilação de DNA , Células Endoteliais/metabolismo , Homocisteína/metabolismo , NF-kappa B/metabolismo , Estresse Oxidativo , Receptores Depuradores Classe E/genética , Receptor 4 Toll-Like/metabolismo , Biomarcadores , Células Cultivadas , Células Endoteliais/efeitos dos fármacos , Regulação da Expressão Gênica , Homocisteína/farmacologia , Humanos , Peróxido de Hidrogênio , Lipoproteínas LDL , Superóxido Dismutase/metabolismo , Receptor 4 Toll-Like/genéticaRESUMO
Vascular smooth muscle cell (VSMC) proliferation is a primary pathological event in atherosclerosis (AS), and homocysteine (Hcy) is an independent risk factor for AS. However, the underlying mechanisms are still lagging. Studies have used the combination of methylation of promoters of multiple genes to diagnose tumors, thus the aim of the current study was to investigate the role of methylation status of several genes in VSMCs treated with Hcy. CpG islands were identified in the promoters of plateletderived growth factor (PDGF), p53, phosphatase and tensin homologue on chromosome 10 (PTEN) and mitofusin 2 (MFN2). Hypomethylation was observed to occur in the promoter region of PDGF, hypermethylation in p53, PTEN and MFN2, and hypomethylation in two global methylation indicators, aluminium (Alu) and long interspersed nucleotide element1 (Line1). This was accompanied by an increase in the expression of PDGF, and reductions of p53, PTEN and MFN2, both in mRNA and protein levels. An elevation of Sadenosylmethionine (SAM) and a reduction of Sadenosylhomocysteine (SAH) and the SAM/SAH ratio were also identified. In conclusion, Hcy impacted methylation the of ASassociated genes and global methylation status that mediate the cell proliferation, which may be a character of VSMCs treated with Hcy. The data provided evidence for mechanisms of VSMCs proliferation in AS induced by Hcy and may provide a new perspective for AS induced by Hcy.
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Metilação de DNA/efeitos dos fármacos , Epigênese Genética , Homocisteína/farmacologia , Miócitos de Músculo Liso/efeitos dos fármacos , Regiões Promotoras Genéticas , Elementos Alu , Aterosclerose/genética , Aterosclerose/metabolismo , Aterosclerose/patologia , Proliferação de Células/efeitos dos fármacos , Ilhas de CpG , Feminino , GTP Fosfo-Hidrolases/genética , GTP Fosfo-Hidrolases/metabolismo , Humanos , Elementos Nucleotídeos Longos e Dispersos , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Modelos Biológicos , Músculo Liso Vascular/citologia , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/metabolismo , Miócitos de Músculo Liso/citologia , Miócitos de Músculo Liso/metabolismo , PTEN Fosfo-Hidrolase/genética , PTEN Fosfo-Hidrolase/metabolismo , Fator de Crescimento Derivado de Plaquetas/genética , Fator de Crescimento Derivado de Plaquetas/metabolismo , Cultura Primária de Células , S-Adenosil-Homocisteína/metabolismo , S-Adenosilmetionina/metabolismo , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , Veias Umbilicais/citologia , Veias Umbilicais/efeitos dos fármacos , Veias Umbilicais/metabolismoRESUMO
After the publication of the article, the authors noted that they had made an error regarding the order of one of their names. For Professor Zheng Yu, the given name is Yu and the family name is Zheng, therefore he should be listed as Professor Yu Zheng in the author list and as the corresponding author. [the original article was published in the Molecular Medicine Reports 13: 4791-4799, 2016; DOI: 10.3892/mmr.2016.5120].
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The aim of the present study was to identify an effective method for detecting earlyphase atherosclerosis (AS), as well as to provide useful DNA methylation profiles to serve as biomarkers for the detection of AS. A total of 300 individuals (150 AS patients and 150 healthy subjects) were recruited for peripheral blood DNA methylation analyses at 12 gene promoter loci using nested methylationspeciï¬c polymerase chain reaction in a test set. Based on the test set, the promoter methylation of TIMP metallopeptidase inhibitor 1 (TIMP1), ATP binding cassette subfamily A member 1 (ABCA1), and acetyl-CoA acetyltransferase 1 (ACAT1) were determined to be candidate biomarkers; demonstrating the highest sensitivity (88%) and specificity (90%). The biomarkers that were candidates for early AS detection were validated in an independent validation set (n=100). In the validation set, the combination of TIMP1, ABCA1 and ACAT1 methylation achieved sensitivity, specificity and coincidence rate values of 88, 70 and 79%, respectively. In the current pilot study, the patterns of DNA methylation of ASassociated genes were observed to be significantly altered in the peripheral blood of AS patients. Thus, the AS-specific methylation of the threegene panel (TIMP1, ABCA1, and ACAT1) may serve as a valuable biomarker for the early detection of AS.
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Aterosclerose/genética , Metilação de DNA , Transportador 1 de Cassete de Ligação de ATP/genética , Acetil-CoA C-Acetiltransferase/genética , Adulto , Aterosclerose/sangue , Aterosclerose/diagnóstico , Biomarcadores Tumorais/genética , DNA/sangue , DNA/genética , Diagnóstico Precoce , Feminino , Expressão Gênica , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Regiões Promotoras Genéticas , Medição de Risco , Inibidor Tecidual de Metaloproteinase-1/genéticaRESUMO
Accumulating evidence has suggested that homocysteine (Hcy) is an independent risk factor for atherosclerosis (AS). Hcy can promote vascular smooth muscle cell (VSMC) proliferation, which is pivotal in the pathogenesis and progression of AS. The aim of the present study was to investigate the epigenetic regulatory mechanism of microRNA (miR)143mediated VSMCs proliferation induced by Hcy. The results of a 3(4,5dimethylthiazol2yl)2,5diphenyltetrazolium bromide assay revealed that VSMC proliferation was increased by 1.39fold following treatment with 100 mM Hcy, compared with the control group. The levels of miR143 were markedly downregulated in the Hcy group, compared with the control group, as determined using reverse transcriptionquantitative polymerase chain reaction analysis. In addition, the level of miR143 methylation was increased markedly in the VSMCs treated with Hcy, compared with the control, and was reduced following transfection with DNA methyltransferase (DNMT)3a small interfering RNA, determined using methylationspecificPCR. The activities of DNMT3a luciferase were also altered accordingly in VSMCs transfected with premiR143 and miR143 inhibitor, respectively. In addition, the expression of miR143 was observed to be inversely correlated with the mRNA and protein expression of DNMT3 in the VSMCs. Taken together, these findings suggest that DNMT3a is a direct target of miR143, and that the upregulation of DNMT3 is responsible for the hypermethylation of miR143 in Hcy-induced VSMC proliferation.
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DNA (Citosina-5-)-Metiltransferases/metabolismo , Redes Reguladoras de Genes , Homocisteína/farmacologia , MicroRNAs/metabolismo , Músculo Liso Vascular/citologia , Miócitos de Músculo Liso/citologia , Miócitos de Músculo Liso/enzimologia , Proliferação de Células/efeitos dos fármacos , Metilação de DNA/efeitos dos fármacos , Metilação de DNA/genética , DNA Metiltransferase 3A , Regulação para Baixo/efeitos dos fármacos , Redes Reguladoras de Genes/efeitos dos fármacos , Humanos , Miócitos de Músculo Liso/efeitos dos fármacos , Reação em Cadeia da Polimerase , Regiões Promotoras Genéticas/genética , Regulação para Cima/efeitos dos fármacosRESUMO
Homocysteine (Hcy) is an independent risk factor for atherosclerosis, but the underlying molecular mechanisms are not known. We investigated the effects of Hcy on fatty acid-binding protein 4 (FABP4), and tested our hypothesis that Hcy-induced atherosclerosis is mediated by increased FABP4 expression and decreased methylation. The FABP4 expression and DNA methylation was assessed in the aorta of ApoE(-/-) mice fed high-methionine diet for 20weeks. Over-expression of FABP4 enhanced accumulation of total cholesterol and cholesterol ester in foam cells. The up-regulation of DNA methyltransferase 1 (DNMT1) promoted the methylation process and decreased FABP4 expression. These data suggest that FABP4 plays a key role in Hcy-mediated disturbance of lipid metabolism and that DNMT1 may be a novel therapeutic target in Hcy-related atherosclerosis.