Proliferative vitreoretinopathy (PVR) is a blinding eye disease. Epithelial‐mesenchymal transition (EMT) of RPE cells plays an important role in the pathogenesis of PVR. In the current study, we sought to investigate the role of the methyl‐CpG‐binding protein 2 (MeCP2), especially P‐MeCP2‐421 in the pathogenesis of PVR. The expressions of P‐MeCP2‐421, P‐MeCP2‐80, PPAR‐γ and the double labelling of P‐MeCP2‐421 with α‐SMA, cytokeratin, TGF‐β and PPAR‐γ in human PVR membranes were analysed by immunohistochemistry. The effect of knocking down MeCP2 using siRNA on the expressions of α‐SMA, phospho‐Smad2/3, collagen I, fibronectin and PPAR‐γ; the expression of α‐SMA stimulated by recombinant MeCP2 in ARPE‐19; and the effect of TGF‐β and 5‐AZA treatment on PPAR‐γ expression were analysed by Western blot. Chromatin immunoprecipitation was used to determine the binding of MeCP2 to TGF‐β. Our results showed that P‐MeCP2‐421 was highly expressed in PVR membranes and was double labelled with α‐SMA, cytokeratin and TGF‐β, knocking down MeCP2 inhibited the activation of Smad2/3 and the expression of collagen I and fibronectin induced by TGF‐β. TGF‐β inhibited the expression of PPAR‐γ, silence of MeCP2 by siRNA or using MeCP2 inhibitor (5‐AZA) increased the expression of PPAR‐γ. α‐SMA was up‐regulated by the treatment of recombinant MeCP2. Importantly, we found that MeCP2 bound to TGF‐β as demonstrated by Chip assay. The results suggest that MeCP2 especially P‐MeCP2‐421 may play a significant role in the pathogenesis of PVR and targeting MeCP2 may be a potential therapeutic approach for the treatment of PVR. 相似文献
Tumour necrosis factor (TNF)‐α induces cardiac metabolic disorder and mitochondrial dysfunction. Hydrogen sulphide (H2S) contains anti‐inflammatory and biological effects in cardiomyocytes. This study investigated whether H2S modulates TNF‐α‐dysregulated mitochondrial function and metabolism in cardiomyocytes. HL‐1 cells were incubated with TNF‐α (25 ng/mL) with or without sodium hydrosulphide (NaHS, 0.1 mmol/L) for 24 hours. Cardiac peroxisome proliferator‐activated receptor (PPAR) isoforms, pro‐inflammatory cytokines, receptor for advanced glycation end products (RAGE) and fatty acid metabolism were evaluated through Western blotting. The mitochondrial oxygen consumption rate and adenosine triphosphate (ATP) production were investigated using Seahorse XF24 extracellular flux analyzer and bioluminescence assay. Fluorescence intensity using 2′, 7′‐dichlorodihydrofluorescein diacetate was used to evaluate mitochondrial oxidative stress. NaHS attenuated the impaired basal and maximal respiration, ATP production and ATP synthesis and enhanced mitochondrial oxidative stress in TNF‐α‐treated HL‐1 cells. TNF‐α‐treated HL‐1 cells exhibited lower expression of PPAR‐α, PPAR‐δ, phosphorylated 5′ adenosine monophosphate‐activated protein kinase‐α2, phosphorylated acetyl CoA carboxylase, carnitine palmitoyltransferase‐1, PPAR‐γ coactivator 1‐α and diacylglycerol acyltransferase 1 protein, but higher expression of PPAR‐γ, interleukin‐6 and RAGE protein than control or combined NaHS and TNF‐α‐treated HL‐1 cells. NaHS modulates the effects of TNF‐α on mitochondria and the cardiometabolic system, suggesting its therapeutic potential for inflammation‐induced cardiac dysfunction. 相似文献
Tumour necrosis factor (TNF)‐α has been considered to induce ischaemia‐reperfusion injury (IRI) of liver which is characterized by energy dysmetabolism. Peroxisome proliferator–activated receptor‐γ co‐activator (PGC)‐1α and mitofusion2 (Mfn2) are reported to be involved in the regulation of mitochondrial function. However, whether PGC‐1α and Mfn2 form a pathway that mediates liver IRI, and if so, what the underlying involvement is in that pathway remain unclear. In this study, L02 cells administered recombinant human TNF‐α had increased TNF‐α levels and resulted in down‐regulation of PGC‐1α and Mfn2 in a rat liver IRI model. This was associated with hepatic mitochondrial swelling, decreased adenosine triphosphate (ATP) production, and increased levels of reactive oxygen species (ROS) and alanine aminotransferase (ALT) activity as well as cell apoptosis. Inhibition of TNF‐α by neutralizing antibody reversed PGC‐1α and Mfn2 expression, and decreased hepatic injury and cell apoptosis both in cell culture and in animals. Treatment by rosiglitazone sustained PGC‐1α and Mfn2 expression both in IR livers, and L02 cells treated with TNF‐α as indicated by increased hepatic mitochondrial integrity and ATP production, reduced ROS and ALT activity as well as decreased cell apoptosis. Overexpression of Mfn2 by lentiviral‐Mfn2 transfection decreased hepatic injury in IR livers and L02 cells treated with TNF‐α. However, there was no up‐regulation of PGC‐1α. These findings suggest that PGC‐1α and Mfn2 constitute a regulatory pathway, and play a critical role in TNF‐α‐induced hepatic IRI. Inhibition of the TNF‐α or PGC‐1α/Mfn2 pathways may represent novel therapeutic interventions for hepatic IRI. 相似文献
Vascular calcification (VC) is a pathological process underpinning major cardiovascular conditions and has attracted public attention due to its high morbidity and mortality. Chronic kidney disease (CKD) is a common disease related to VC. Ginsenoside Rb1 (Rb1) has been reported to protect the cardiovascular system against vascular diseases, yet its role in VC and the underlying mechanisms remain unclear. In this study, we established a CKD‐associated VC rat model and a β‐glycerophosphate (β‐GP)‐induced vascular smooth muscle cell (VSMC) calcification model to investigate the effects of Rb1 on VC. Our results demonstrated that Rb1 ameliorated calcium deposition and VSMC osteogenic transdifferentiation both in vivo and in vitro. Rb1 treatment inhibited the Wnt/β‐catenin pathway by activating peroxisome proliferator‐activated receptor‐γ (PPAR‐γ), and confocal microscopy was used to show that Rb1 inhibited β‐catenin nuclear translocation in VSMCs. Furthermore, SKL2001, an agonist of the Wnt/β‐catenin pathway, compromised the vascular protective effect of Rb1. GW9662, a PPAR‐γ antagonist, reversed Rb1's inhibitory effect on β‐catenin. These results indicate that Rb1 exerted anticalcific properties through PPAR‐γ/Wnt/β‐catenin axis, which provides new insights into the potential theraputics of VC. 相似文献
We aimed to assess the immunoregulatory effects of IFN‐β in patients with tuberculous pleurisy. IFN‐β, IFN‐γ and IL‐17 expression levels were detected, and correlations among these factors in different culture groups were analyzed. Pleural fluid mononuclear cells (PFMC) from tuberculous pleural effusions, but not peripheral blood mononuclear cells (PBMC) from healthy donors, spontaneously expressed IFN‐β, IL‐17 and IFN‐γ. Moreover, exogenous IFN‐β significantly inhibited the expression of IL‐17 in PFMC. By contrast, IFN‐β simultaneously enhanced the levels of IFN‐γ. To further investigate the regulation of IL‐17 and IFN‐γ by endogenous IFN‐β, an IFN‐β neutralizing antibody was simultaneously added to bacillus Calmette‐Guérin (BCG)‐stimulated PFMC. IL‐17 expression was significantly increased, but IFN‐γ production was markedly decreased in the experimental group supplemented with the IFN‐β neutralizing antibody. Simultaneously, IL‐17 production was remarkably increased in the experimental group supplemented with the IFN‐γ neutralizing antibody. Taken together, in our study, we first found that freshly isolated PFMC, but not PBMC from healthy donors, spontaneously expressed IFN‐β, IL‐17 and IFN‐γ in vivo. Moreover, IFN‐β suppressed IL‐17 expression and increased IFN‐γ production. Furthermore, both IFN‐β and IFN‐γ down‐regulated IL‐17 expression. These observations suggest that caution is required when basing anti‐tuberculosis treatment on the inhibition of IFN‐β signaling. 相似文献
Gastric aspiration lung injury is one of the most common clinical events. This study investigated the effects of bone‐marrow‐derived mesenchymal stem cells (BMSCs) on combined acid plus small non‐acidified particle (CASP)‐induced aspiration lung injury. Enhanced green fluorescent protein (EGFP+) or EGFP? BMSCs or 15d‐PGJ2 were injected via the tail vein into rats immediately after CASP‐induced aspiration lung injury. Pathological changes in lung tissues, blood gas analysis, the wet/dry weight ratio (W/D) of the lung, levels of total proteins and number of total cells and neutrophils in bronchoalveolar lavage fluid (BALF) were determined. The cytokine levels were measured using ELISA. Protein expression was determined by Western blot. Bone‐marrow‐derived mesenchymal stem cells treatment significantly reduced alveolar oedema, exudation and lung inflammation; increased the arterial partial pressure of oxygen; and decreased the W/D of the lung, the levels of total proteins and the number of total cells and neutrophils in BALF in the rats with CASP‐induced lung injury. Bone‐marrow‐derived mesenchymal stem cells treatment decreased the levels of tumour necrosis factor‐α and Cytokine‐induced neutrophil chemoattractant (CINC)‐1 and the expression of p‐p65 and increased the levels of interleukin‐10 and 15d‐PGJ2 and the expression of peroxisome proliferator‐activated receptor (PPAR)‐γ in the lung tissue in CASP‐induced rats. Tumour necrosis factor‐α stimulated BMSCs to secrete 15d‐PGJ2. A tracking experiment showed that EGFP+ BMSCs were able to migrate to local lung tissues. Treatment with 15d‐PGJ2 also significantly inhibited CASP‐induced lung inflammation and the production of pro‐inflammatory cytokines. Our results show that BMSCs can protect lung tissues from gastric aspiration injury and inhibit lung inflammation in rats. A beneficial effect might be achieved through BMSC‐derived 15d‐PGJ2 activation of the PPAR‐γ receptor, reducing the production of proinflammatory cytokines. 相似文献
Sevoflurane is the most widely used anaesthetic administered by inhalation. Exposure to sevoflurane in neonatal mice can induce learning deficits and abnormal social behaviours. MicroRNA (miR)‐27a‐3p, a short, non‐coding RNA that functions as a tumour suppressor, is up‐regulated after inhalation of anaesthetic, and peroxisome proliferator‐activated receptor γ (PPAR‐γ) is one of its target genes. The objective of this study was to investigate how the miR‐27a‐3p–PPAR‐γ interaction affects sevoflurane‐induced neurotoxicity. A luciferase reporter assay was employed to identify the interaction between miR‐27a‐3p and PPAR‐γ. Primary hippocampal neuron cultures prepared from embryonic day 0 C57BL/6 mice were treated with miR‐27a‐3p inhibitor or a PPAR‐γ agonist to determine the effect of miR‐27a‐3p and PPAR‐γ on sevoflurane‐induced cellular damage. Cellular damage was assessed by a flow cytometry assay to detect apoptotic cells, immunofluorescence to detect reactive oxygen species, western blotting to detect NADPH oxidase 1/4 and ELISA to measure inflammatory cytokine levels. In vivo experiments were performed using a sevoflurane‐induced anaesthetic mouse model to analyse the effects of miR‐27a‐3p on neurotoxicity by measuring the number of apoptotic neurons using the Terminal‐deoxynucleoitidyl Transferase Mediated Nick End Labeling (TUNEL) method and learning and memory function by employing the Morris water maze test. Our results revealed that PPAR‐γ expression was down‐regulated by miR‐27a‐3p following sevoflurane treatment in hippocampal neurons. Down‐regulation of miR‐27a‐3p expression decreased sevoflurane‐induced hippocampal neuron apoptosis by decreasing inflammation and oxidative stress‐related protein expression through the up‐regulation of PPAR‐γ. In vivo tests further confirmed that inhibition of miR‐27a‐3p expression attenuated sevoflurane‐induced neuronal apoptosis and learning and memory impairment. Our findings suggest that down‐regulation of miR‐27a‐3p expression ameliorated sevoflurane‐induced neurotoxicity and learning and memory impairment through the PPAR‐γ signalling pathway. MicroRNA‐27a‐3p may, therefore, be a potential therapeutic target for preventing or treating sevoflurane‐induced neurotoxicity.
Cardiomyocyte tumour necrosis factor α (TNF‐α) production contributes to myocardial depression during sepsis. This study was designed to observe the effect of norepinephrine (NE) on lipopolysaccharide (LPS)‐induced cardiomyocyte TNF‐α expression and to further investigate the underlying mechanisms in neonatal rat cardiomyocytes and endotoxaemic mice. In cultured neonatal rat cardiomyocytes, NE inhibited LPS‐induced TNF‐α production in a dose‐dependent manner. α1‐ adrenoceptor (AR) antagonist (prazosin), but neither β1‐ nor β2‐AR antagonist, abrogated the inhibitory effect of NE on LPS‐stimulated TNF‐α production. Furthermore, phenylephrine (PE), an α1‐AR agonist, also suppressed LPS‐induced TNF‐α production. NE inhibited p38 phosphorylation and NF‐κB activation, but enhanced extracellular signal‐regulated kinase 1/2 (ERK1/2) phosphorylation and c‐Fos expression in LPS‐treated cardiomyocytes, all of which were reversed by prazosin pre‐treatment. To determine whether ERK1/2 regulates c‐Fos expression, p38 phosphorylation, NF‐κB activation and TNF‐α production, cardiomyocytes were also treated with U0126, a selective ERK1/2 inhibitor. Treatment with U0126 reversed the effects of NE on c‐Fos expression, p38 mitogen‐activated protein kinase (MAPK) phosphorylation and TNF‐α production, but not NF‐κB activation in LPS‐challenged cardiomyocytes. In addition, pre‐treatment with SB202190, a p38 MAPK inhibitor, partly inhibited LPS‐induced TNF‐α production in cardiomyocytes. In endotoxaemic mice, PE promoted myocardial ERK1/2 phosphorylation and c‐Fos expression, inhibited p38 phosphorylation and IκBα degradation, reduced myocardial TNF‐α production and prevented LPS‐provoked cardiac dysfunction. Altogether, these findings indicate that activation of α1‐AR by NE suppresses LPS‐induced cardiomyocyte TNF‐α expression and improves cardiac dysfunction during endotoxaemia via promoting myocardial ERK phosphorylation and suppressing NF‐κB activation. 相似文献
Hepatic fibrosis is concomitant with sinusoidal pathological angiogenesis, which has been highlighted as novel therapeutic targets for the treatment of chronic liver disease. Our prior studies have demonstrated that curcumin has potent antifibrotic activity, but the mechanisms remain to be elucidated. The current work demonstrated that curcumin ameliorated fibrotic injury and sinusoidal angiogenesis in rat liver with fibrosis caused by carbon tetrachloride. Curcumin reduced the expression of a number of angiogenic markers in fibrotic liver. Experiments in vitro showed that the viability and vascularization of rat liver sinusoidal endothelial cells and rat aortic ring angiogenesis were not impaired by curcumin. These results indicated that hepatic stellate cells (HSCs) that are characterized as liver‐specific pericytes could be potential target cells for curcumin. Further investigations showed that curcumin inhibited VEGF expression in HSCs associated with disrupting platelet‐derived growth factor‐β receptor (PDGF‐βR)/ERK and mTOR pathways. HSC motility and vascularization were also suppressed by curcumin associated with blocking PDGF‐βR/focal adhesion kinase/RhoA cascade. Gain‐ or loss‐of‐function analyses revealed that activation of peroxisome proliferator‐activated receptor‐γ (PPAR‐γ) was required for curcumin to inhibit angiogenic properties of HSCs. We concluded that curcumin attenuated sinusoidal angiogenesis in liver fibrosis possibly by targeting HSCs via a PPAR‐γ activation‐dependent mechanism. PPAR‐γ could be a target molecule for reducing pathological angiogenesis during liver fibrosis. 相似文献
This study aimed to investigate the protective effects and underlying mechanisms of cistanche on sevoflurane‐induced aged cognitive dysfunction rat model. Aged (24 months) male SD rats were randomly assigned to four groups: control group, sevoflurane group, control + cistanche and sevoflurane + cistanche group. Subsequently, inflammatory cytokine levels were measured by ELISA, and the cognitive dysfunction of rats was evaluated by water maze test, open‐field test and the fear conditioning test. Three days following anaesthesia, the rats were killed and hippocampus was harvested for the analysis of relative biomolecules. The oxidative stress level was indicated as nitrite and MDA concentration, along with the SOD and CAT activity. Finally, PPAR‐γ antagonist was used to explore the mechanism of cistanche in vivo. The results showed that after inhaling the sevoflurane, 24‐ but not 3‐month‐old male SD rats developed obvious cognitive impairments in the behaviour test 3 days after anaesthesia. Intraperitoneal injection of cistanche at the dose of 50 mg/kg for 3 consecutive days before anaesthesia alleviated the sevoflurane‐induced elevation of neuroinflammation levels and significantly attenuated the hippocampus‐dependent memory impairments in 24‐month‐old rats. Cistanche also reduced the oxidative stress by decreasing nitrite and MDA while increasing the SOD and CAT activity. Moreover, such treatment also inhibited the activation of microglia. In addition, we demonstrated that PPAR‐γ inhibition conversely alleviated cistanche‐induced protective effect. Taken together, we demonstrated that cistanche can exert antioxidant, anti‐inflammatory, anti‐apoptosis and anti‐activation of microglia effects on the development of sevoflurane‐induced cognitive dysfunction by activating PPAR‐γ signalling. 相似文献
Hesperidin (HES), a flavanone glycoside, predominant in citrus fruits, has an agonistic activity on peroxisome proliferator‐activated receptor gamma (PPAR‐γ). PPAR‐γ is an inhibitor of cardiac hypertrophy (CH) signaling pathways. In this study, we investigated the cardioprotective effect of HES in isoproterenol (ISO)‐induced CH through PPAR‐γ agonistic activity. For this, male albino Wistar rats were divided into six groups (n = 6), that is, normal, ISO‐control, HES treatment group (200 mg kg?1; p.o.), HES per se (200 mg kg?1; p.o.), enalapril treatment group (30 mg kg?1; p.o.), and combination group (HES 200 mg kg?1; p.o.+enalapril 30 mg kg?1; p.o.). ISO (3 mg kg?1; s.c.) was administered to all groups except normal and per se to induce CH. HES or enalapril treatment of 28 days significantly attenuated pathological changes, improved cardiac hemodynamics, suppressed oxidative stress, and apoptosis along with an increased PPAR‐γ expression. The combination of enalapril with HES exhibited an effect similar to that of HES or enalapril alone on all the aforementioned parameters. Therefore, HES may be further evaluated as a promising molecule for the alleviation of CH. 相似文献