Protective effect of SIRT1 on rat mesangial cells by decreasing high glucose-induced acetylation of NF-κB p65

AIM: To investigate the effects of silent information regulator 1 (SIRT1) on high glucose-induced acetylation of NF-κB p65 subunit and its protective role in rat mesangial cells. METHODS: Rat mesangial cells were cultured in DMEM supplemented with 10% FBS and were divided into control group, mannitol group, high glucose group, resveratrol group and SIRT1 RNAi group. The cell viability was determined by MTT assay. The mRNA expression of SIRT1, monocyte chemoattratant protein 1 (MCP-1), vascular cell adhesion molecule 1 (VCAM-1-1), tumor necrosis factor α (TNF-α), transforming growth factor β1 (TGF-β1) was analyzed by real-time quantitative PCR. The protein expression of SIRT1 and the acetylation of NF-κB p65 subunit were determined by Western blotting. The protein concentrations of MCP-1, VCAM-1, TNF-α, TGF-β1 and malondialdehyde (MDA) were detected by ELISA. RESULTS: The cell viability, superoxide dismutase (SOD) activity, and the expression of SIRT1 at mRNA and protein levels were decreased by high glucose treatment as compared with control group. The acetylation of NF-κB p65 subunit was significantly increased after interfered with high glucose, resulting in the increase in the secretion of MCP-1, VCAM-1, TNF-α and TGF-β1. Resveratrol decreased high glucose-induced acetylation of NF-κB p65 subunit. However, silencing SIRT1 significantly enhanced the acetylation of NF-κB p65 subunit and the expression of MCP-1, VCAM-1, TNF-α and TGF-β1. CONCLUSION: SIRT1 remarkably inhibits the inflammatory reactions by deacetylating NF-κB p65, suggesting that SIRT1 is a possible target for preventing diabetic nephropathy.     

Effects of miR-155 over-expression on expression of inflammatory factors and indolamine 2, 3-dioxygenase in microglial BV-2 cells

AIM:To explore the effect of microRNA-155(miR-155)over-expression on the expression of inflammatory factors and indolamine 2, 3- dioxygenase (IDO) in the microglial BV-2 cells. METHODS:For over-expression of miR-155, the BV-2 cells were transfected with lentiviral vector carrying mmu-miR-155. The expression of inflammatory factors was detected by cytometric bead array system (CBA). The mRNA expression of inflammatory factors and IDO was analyzed by real-time PCR. The protein levels of suppressor of cytokine signalling 1 (SOCS1), p-p38 MAPK and IDO were determined by Western blot. RESULTS:The expression of miR-155 was up-regulated in the BV-2 cells transfected with lentiviral vector carrying mmu-miR-155 compared with LPS treatment group (P<0.01). The miR-155 over-expression promoted the secretion of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), monocyte chemotactic protein-1 (MCP-1) and IL-10, and inhibited the secretion of IL-12. The miR-155 over-expression increased the mRNA expression of IL-6, TNF-α, IL-10 and IDO, also increased the protein levels of IDO and p-p38 MAPK, but decreased the protein expression of SOCS1 (P<0.01). LPS promoted the secretion of IL-6, TNF-α, MCP-1 and IL-12, also increased the mRNA expression of IL-6, TNF-α and IDO, meanwhile, increased the protein levels of IDO, p-p38 MAPK and SOCS1 (P<0.01). CONCLUSION:Over-expression of miR-155 promotes the secretion of related imflammatory factors and protein expression of IDO in microglial BV-2 cells mediated with SOCS1 and p38 MAPK signaling pathway.     

Lectin-like oxidized low density lipoprotein receptor-1 mediates expression of MCP-1 induced by ox-LDL in cultured human vascular endothelial cells

AIM: To investigate the effects of lectin-like oxidized low density lipoprotein receptor-1 (LOX-1) on the expression of MCP-1 in the cultured human unbilical vein endothelial cells (HUVECs). METHODS: Cultured HUVECs was incubated with ox-LDL, or preincubated with carrageenan and polyinosinic acid. LOX-1 and MCP-1 mRNA and protein were determined by RT-PCR and Western blot. RESULTS: Incubation of HUVECs with ox-LDL (from 0-100 mg/L) for 24 h markedly increased the expression of LOX-1 and MCP-1 (mRNA and protien) in a concentration-dependent fashion. Preincubation of HUVECs with carrageenan and polyinosinic acid, the chemical inhibitors of LOX-1, for 2 h, ox-LDL-mediated upregulation of LOX-1 and MCP-1 was suppressed (P<0.05). CONCLUSION: These findings indicate that ox-LDL upregulates MCP-1 and its own endothelial receptor, and ox-LDL-induced MCP-1 is mediated by the action of LOX-1. LOX-1 plays a critical role in the pathogenesis of atherosclerosis.     

Extract of Ginkgo Biloba decreased expression of lectin-like oxidized low density lipoprotein receptor-1 induced by TNF-α in bovine aortic endothelial cells

AIM: To investigate the effects of extract of Ginkgo biloba (EGB) on the expression of lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) induced by tumor necrosis factor a(TNF-α) in bovine aortic endothelial cells(BAECs). METHODS: The BAECs were incubated with TNF-α, followed by EGB treatment. The effect of EGB on LOX-1 expression was investigated by RT-PCR and Western blotting. The content of endothelial nitric oxide synthase (eNOS) was determined by Western blotting. Potential involvement of signaling pathways of the effects was explored by using related inhibitors of the signal molecules. The concentration of NO^-₂/NO^-₃ was also tested. RESULTS: Increased LOX-1 expression was induced by TNF-α. EGB markedly prevented the increase of LOX-1 expression induced by TNF-α (P<0.05), and this effect was inhibited by inhibitor of NOS (P<0.05). EGB significantly prevented the decrease of eNOS expression induced by TNF-α (P<0.05). EGB also significantly prevented the decrease of NO^-₂/NO^-₃ production induced by TNF-α (P<0.05). CONCLUSION: EGB markedly prevents the increase of LOX-1 expression induced by TNF-α and the effect is mediated by eNOS.     

Angiotensin 1-7 attenuates angiotensin Ⅱ-induced human glomerular endothelial cell injury via Mas receptor

AIM:To investigate the effect of angiotensin 1-7 (Ang1-7) on the human glomerular endothelial cells (HGECs) injury induced by angiotensin Ⅱ (Ang Ⅱ) and its possible mechanism. METHODS:Cultured HGECs were divided into 6 groups randomly:control group, Ang Ⅱ group, Ang1-7 group, Ang Ⅱ +Ang1-7 group, Ang Ⅱ +Ang1-7+A779 (an inhibitor of Mas receptor) group and A779 group. The apoptotic rate and reactive oxygen species (ROS) of HGECs were analyzed by flow cytometry and photographed by fluorescence microscopy. The levels of lactate dehydrogenase (LDH), nitric oxide (NO), endothelin-1 (ET-1), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), transforming growth factor-β (TGF-β), monocyte chemoattractant protein-1 (MCP-1) and intercellular adhesion molecule-1 (ICAM-1) in the supernatant of cell cultures were measured. RESULTS:Compared with the control group, the apoptotic rate and the average fluorescence intensity of ROS were increased in the Ang Ⅱ group, IL-6, TNF-α, TGF-β, ICAM-1 and MCP-1 in cell supernatants were also increased in the Ang Ⅱ group (P<0.05). Compared with the Ang Ⅱ group, the apoptotic rate, ROS level, and the above inflammatory factors were decreased in Ang Ⅱ +Ang1-7 group (P<0.05). Compared with the Ang Ⅱ +Ang1-7 group, adding A779 increased the cell apoptotic rate, ROS production and the releases of the above inflammatory factors in cell supernatants (P<0.05). Compared with the Ang Ⅱ group, adding Ang1-7 inhibited the LDH leakage, ET-1 secretion and promoted the release of NO in a dose-dependent manner (P<0.05). CONCLUSION:Ang1-7 attenuates the HGECs injury induced by Ang Ⅱ by inhibiting the Mas receptor.     

Rosuvastatin inhibits up-regulation of inflammatory factors in endothelial outgrowth cells induced by C-reactive protein

AIM：To study the effects of rosuvastatin on C-reactive protein (CRP)-induced expression of inflammatory factors in endothelial outgrowth cells (EOCs). METHODS：Mononuclear cells (MNCs) were isolated from human umbilical cord blood by density gradient centrifugation. EOCs were treated with CRP at concentration of 5, 10, 25 and 50 mg/L and were exposed to 50 mg/L CRP for different time (0, 3, 6 and 12 h). In addition, EOCs were pre-incubated with rosuvastatin at different concentrations (10-8, 10-7 and 10-6mol/L) for 12 h and then stimulated with 50 mg/L CRP. The mRNA levels of IL-8, MCP-1, VCAM-1 and ICAM-1 in EOCs were measured by quantitative PCR. The protein levels of MCP-1 and VCAM-1 were detected by ELISA. RESULTS：CRP dose-dependently increased the mRNA levels of inflammatory factors (IL-8, MCP-1, VCAM-1 and ICAM-1) and protein levels of MCP-1 and VCAM-1. The mRNA levels of IL-8, VCAM-1, and ICAM-1 in EOCs reached to the peak at 6 h, while MCP-1 peaked at 3 h when treated with 50 mg/L CRP. The protein levels of MCP-1 and VCAM-1 increased in a time-dependent manner. The mRNA and protein levels of the inflammatory factors were significantly decreased by treatment with rosuvastatin at different concentrations. CONCLUSION：CRP is not just an inflammatory marker as CRP induces inflammation in EOCs. Rosuvastatin attenuates CRP-induced inflammatory response in EOCs, indicating a new target for the prevention of atherosclerosis.     

Protective effects of sequoyitol on type 2 diabetic rats with liver inflammatory lesions

AIM：To investigate the possible protective effect of sequoyitol on type 2 diabetic rats with liver inflammatory lesions. METHODS：Type 2 diabetic rats were induced by feeding high-fat/high-sugar diet and injecting with a low dose of streptozotocin. Sequoyitol at doses of 12.5, 25 and 50 mg·kg-1·d-1 was orally administered in the model rats. At the end of the experiment, the rats were sacrificed. Serum levels of fasting blood glucose, alanine aminotransferase(ALT), aspartate aminotransferase(AST) and albumin(ALB) were determined. Liver wet was recorded and liver index was calculated. The levels of C-reactive protein(CRP),tumor necrosis factor α(TNF-α) and interleukin 6(IL-6) in the liver tissues were also measured. Real-time PCR was used to determine the mRNA expression of TNF-α. In addition, the pathological changes of the liver were observed with HE staining. RESULTS：Compared with the model rats, treatment with sequoyitol obviously decreased the levels of fasting blood glucose, ALT, AST, ALB, CRP, TNF-α and IL-6, reduced the liver index, down-regulated the mRNA expression of TNF-α in the liver, and ameliorated the pathologic changes of the liver. CONCLUSION：Sequoyitol attenuates liver lesions in type 2 diabetic rats through down-regulation of TNF-α and IL-6 expression.     

Effects of puerarin combined with saxagliptin on renal fibrosis in type 2 diabetic rats

AIM：To observe the effects of puerarin combined with saxagliptin on renal fibrosis in type 2 diabetic rats. METHODS：Fifty male Wistar rats were used, of which 8 rats were randomly chosen as normal control group, and the remaining rats were used to establish the type 2 diabetic model. The rats that met the criterion for the diabetic mo-del were randomly divided into model group, puerarin treatment group, saxagliptin treatment group, puerarin combined with saxagliptin treatment group and metformin combined with saxagliptin treatment group. The above-mentioned drugs were administered for 8 weeks. After that period, all rats were sacrificed. The kidney index (kidney weight/body weight),and blood glucose and HbA1c were examined in all the rats. The morphological changes were observed by HE and Masson staining. The levels of TNF-α and macrophage migration inhibitory factor (MIF) in the serum were measured by ELISA. The mRNA expression of TNF-α, MIF and CD68 was examined by RT-PCR. RESULTS：Compared with normal group, the kidney index, blood glucose and HbA1c, the levels of TNF-α and MIF in the serum and the mRNA expression of TNF-α, MIF and CD68 were increased (P<0.05) in the kidney tissues of model group. Compared with model group, the kidney index, blood glucose and HbA1c, the levels of MIF and TNF-α in the serum and the mRNA expression of TNF-α, MIF and CD68 were decreased (P<0.05) in puerarin combined with saxagliptin treatment group. CONCLUSION：Puerarin combined with saxagliptin reduces blood glucose, decreases MIF and TNF-α, and down-regulates the mRNA expression of TNF-α, MIF and CD68 in the kidney tissues of type 2 diabetic rats, which may contribute to the inhibition of renal fibrosis.     

Anthocyanins attenuates hepatic fibrosis and inflammation in non-alcoho-lic fatty liver disease mice

AIM:To explore the therapeutic effect of anthocyanins from Fructus Acanthophorae on high-fat diet-induced non-alcoholic fatty liver disease (NAFLD) in mice and the potential mechanism. METHODS:NAFLD mouse model was established by high-fat diet, and interferred with anthocyanins. The liver weight, and serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), triglyceride (TG), total cholesterol (TC) and low-density li-poprotein cholesterol (LDL-C) were measured. The liver tissues were staining with HE, Oil Red O and Masson's trichrome. The protein levels of inflammatory factors tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), IL-6 and IL-10 in the liver tissues were determined by Western blot. The liver macrophage, white blood cell and mononuclear cell infiltration was detected by immunohistochemical method. The chemokines CCL7 and MCP-1 were also measured by immunohistochemical method. RESULTS:Anthocyanins significantly inhibited the increases in the liver weight, ALT, AST, TG, TC and LDL-C induced by high-fat diet. Anthocyanins attenuated the liver fibrosis and inflammatory cell infiltration caused by high-fat diet, and reduced the levels of inflammatory factors TNF-α, IL-1β, IL-6, IL-10 and inflammatory chemokines CCL7 and MCP-1 in the liver tissues. CONCLUSION:Anthocyanins significantly alleviate non-alcoholic fatty liver disease caused by high-fat diet though reducing inflammatory factors, inflammatory cell infiltration and inflammatory chemokines.     

Serum levels of inflammatory factors and adiponectin in type 2 diabetic retinopathy patients

AIM: To investigate the serum levels of inflammatory factors and adiponectin in type 2 diabetic retinopathy (DR) patients.METHODS: One hundred and ten cases of type 2 diabetic patients were divided into 3 groups: no diabetic retinopathy group (DM, n=35), non-proliferative diabetic retinopathy group (NPDR, n=45), and proliferative diabetic retinopathy group (PDR, n=30). Other 40 normal persons served as controls (NC group). The physical examinated was performed for each patient. Serum levels of fasting plasma glucose (FPG), glycated hemoglobin A1c (HbA1c), 2 h postprandial plasma glucose (2hPG), fasting insulin (FINS), total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), adiponectin, intercellular adhesion molecule-1(ICAM-1), tumor necrosis factor-α (TNF-α) and high-sensitivity C-reactive protein (hs-CRP) were measured. Insulin resistance index (HOMA-IR) was also calculated.RESULTS: The systolic blood pressure, body-mass index, waist-hip ratio, serum levels of TG, LDL-C, FPG, 2hPG, HbA1c, ICAM-1, TNF-α, hs-CRP and HOMA-IR were significantly higher in DM group, NPDR group and PDR group than those in NC group (P<0.05). The systolic blood pressure, serum levels of ICAM-1, TNF-α, hs-CRP and HOMA-IR were higher in NPDR group and PDR group than those in DM group (P<0.05). The serum concentration of adiponectin was lower in DM group, NPDR group and PDR group than that in NC group (P<0.05), and that was also lower in NPDR group and PDR group than that in DM group (P<0.05). The negative correlations between adiponectin and ICAM-1 (r=-0.735,P<0.01), TNF-α (r=-0.781,P<0.01), hs-CRP (r=-0.768, P<0.01) or HOMA-IR (r=-0.752, P<0.01) were observed. The relationships between HOMA-IR and ICAM-1 (r=0.857,P<0.01), TNF-α (r=-0.906, P<0.01) or hs-CRP (r=-0.888,P<0.01) were positive.CONCLUSION: The results suggest that inflammatory refactors and adiponectin play important roles in the pathophysiology and progression of DR. The protective effects of adiponectin on DR may be related with its anti-inflammatory reactions to improve insulin resistant.     

CXCL16 deficiency attenuates STZ-induced diabetic nephropathy in mice

AIM: To explore the effect of CXCL16 deficiency on streptozocin (STZ)-induced diabetic nephropathy in mice. METHODS: CXCL16 knockout (C16 KO) mice (8 years old) were used to build up diabetes model by treating with STZ.Age- and gender-matched wild-type (WT) C57BL/6J mice treated with STZ were used as control. All mice were fed with chow diets for 12 weeks, and the development of diabetic nephropathy was evaluated. RESULTS: Compared with the WT mice treated with STZ, C16 KO mice treated with STZ presented lower fasting glucose levels and better glucose tolerance power. C16 KO mice treated with STZ also had lower urine protein levels and smaller areas of glomerular injury as compared with WT mice treated with STZ. Furthermore, CXCL16 deficiency decreased the contents of renal reactive oxygen species (ROS), malondialdehyde (MDA) and oxidized low-density lipoprotein (ox-LDL) and the mRNA expression of lectin-like oxidized low-density lipoprotein receptor 1 (Lox-1), and attenuated the expression of renal inflammatory factors including tumor necrosis factor α (TNF-α) and interleukin 6 (IL-6), as well as chemokines including intercellular cell adhesion molecular 1 (ICAM-1) and chemokine C-X-C motif ligand 1 (CXCL1). CONCLUSION: CXCL16 deficiency obviously inhibits the development of STZ-induced diabetic nephropathy in mice.     

Dual roles of oxidized LDL in modulating expression of inflammatory molecules in HUVECs

AIM:To determine the role of LOX-1/PPAR pathway in regulating expression of adhesion molecules elicited by oxidizing low density lipoprotein(Ox-LDL) through Lectin-like oxidized low-density lipoprotein receptor-1(LOX-1) in human umbilical vein endothelial cells(HUVECs). METHODS:HUVECs were incubated with Ox-LDL,poly(I),carrageenan or 15-deoxy-△12,14-prostaglanding J2 (15d-PGJ₂ ). PPAR mRNA and protein were examined by real time RT-PCR and Western blotting. ICAM-1 and E-selectin were detected by RT-PCR and Western blotting respectively. RESULTS:Ox-LDL increased PPAR expression in HUVECs,which was inhibited by pretreatment of HUVECs with LOX-1 blockers. Preincubation of HUVECs with 15d-PGJ₂ attenuated the expression of intercellular adhesion molecule-1(ICAM-1) and E-selectin in response to Ox-LDL. Upregulation of ICAM-1 and E-selectin mediated by Ox-LDL were suppressed more significantly by the combination of 15d-PGJ₂ and polyinosonic acid as compared to either 15d-PGJ₂ or polyinosonic acid alone. CONCLUSION:The results indicate that Ox-LDL exerts a biphasic effects on inflammatory response. It evokes harmful effects by inflammatory injury on one side and protective effects by triggering the LOX-1/ PPAR signaling pathway on the other hand.     

Effects of resveratrol on TNF-α-induced injury and expression of MCP-1 in isolated rat pulmonary artery endothelial cells

AIM: To investigate the possible mechanism of resveratrol (Res) on tumor necrosis factor-α (TNF-α)-induced monocyte chemoattractant protein-1 (MCP-1) expression in primary rat pulmonary artery endothelial cells (RPAECs).METHODS: RPAECs were randomly divided into 4 groups:control group, solvent (1% DMSO) group, TNF-α group and Res group. Each group was divided into 1 h, 4 h and 8 h subgroups (n=6 per time point). The TNF-α+C1142 (a rodent chimeric mAb that neutralizes rat MCP-1) group was set up at the 8 h time point. At each time point, the protein and mRNA expression of MCP-1 was measured by Western blot and real-time PCR.RESULTS: Pretreatment of the RPAECs with C1142 significantly down-regulated the expression of MCP-1 (P<0.05). The protein and mRNA expression of MCP-1 was markedly increased in TNF-α group (P<0.05). Notably, incubation with Res down-re-gulated the protein and mRNA expression of MCP-1, which was significantly lower than that in TNF-α group (P<0.05).CONCLUSION: MCP-1 was involved in the process of TNF-α-induced injury of RPAECs. Res down-regulates the expression of MCP-1 in RPAECs, thus attenuating cell injury.     

Effects of rosiglitazone on expression of SOCS1/SOCS3 and inflammatory reaction in RAW 264.7 cell-derived foam cells

AIM: To investigate whether perioxisome proliferator-activated receptor γ (PPARγ) ligand rosiglitazone regulates suppressor of cytokine signaling 1 (SOCS1) and SOCS3 expression as well as pro-inflammatory/anti-inflammatory responses in RAW 264.7 cell-derived foam cells. METHODS: The concentrations of TNF-α, IL-6 and IL-10 in the cultured supernatant of RAW 264.7 cell-derived foam cells were detected by ELISA, and the ratios of TNF-α/IL-10 and IL-6/IL-10 were calculated. RT-PCR and Western blotting were used to analyze the effects of rosiglitazone on the expression of SOCS1 and SOCS3 at mRNA and protein levels. RESULTS: The concentrations of TNF-α, IL-6 and IL-10, and ratios of TNF-α/IL-10 and IL-6/IL-10 in foam cell group were obviously higher than those in control group, but the concentrations of the above factors in oxidized low-density lipoprotein (ox-LDL) +rosiglitazone group were apparently lower than those in foam cell group. The expression of SOCS1 and SOCS3 at mRNA and protein levels in oxLDL+rosiglitazone group was apparently higher than that in control and foam cell group. CONCLUSION: PPARγ ligand rosiglitazone up-regulates the expression of SOCS1 and SOCS3 at mRNA and protein levels and regulates the balance of pro-inflammatory/anti-inflammatory responses in RAW 264.7 cell-derived foam cells.     

Effect of taurine on kidney injury induced by paraquat poisoning in rats

AIM:To study the effects of taurine at different doses on renal oxidative stress and inflammation induced by paraquat in rats.METHODS:Male SD rats (n=48) were randomly divided into 4 groups:negative control group,paraquat group,paraquat+low-dose taurine group,and paraquat+high-dose taurine group.The serum levels of creatinine and urea nitrogen were detected by a biochemical analyzer.The levels of malondialdehyde (MDA) and superoxide dismutase (SOD) were measured by colorimetry.The plasma concentrations of IL-6 and intercellular adhesion molecule (ICAM)-1 were detected by ELISA.Renal reactive oxygen species (ROS) was checked by fluorescence probe dihydroethidium (DHE).The protein levels of renal p-P38 MAPK,p-ERK1/2 and p-JNK were determined by Western blot.The mRNA expression of TNF-α,IL-6 and TGF-β1 was detected by real-time PCR.RESULTS:Serum creatinine and urea nitrogen increased after paraquat poisoning,and decreased after feeding with taurine in poisoned rats,with better result in high-dose taurine group.Taurine reduced the oxidative stress and inflammation in the renal tissue,and also reduced the protein levels of p-JNK,p-ERK1/2 and p-P38 in the kidney of paraquat-poisoned rats.CONCLUSION:Taurine attenuates renal injury induced by paraquat poisoning in rats.The mechanism may be related to reducing renal MAPK activity,oxidative stress and inflammatory response.     

Adipophilin induces expression of inflammatory factors through ERK1/2-AP-1 signaling pathway

AIM: To observe the effects of adipose differentiation-related protein (adipophilin) on the expression of inflammatory factors in RAW264.7 macrophage and to clarify the related mechanism. METHODS: The cell models with high expression and low expression of adipophilin were constructed by transfecting PA317 packaging cells with stable high or low expression adipophilin retroviral vectors into the RAW264.7 cells. The concentrations of IL-6, MCP-1 and TNF-α in the cell culture medium were detected by ELISA. The protein levels of AP-1, p-AP-1, ERK1/2 and p-ERK1/2 were measured by Western blot. The protein levels of adipophilin, p-ERK1/2 and p-AP-1 and the releases of the inflammatory factors in the RAW264.7 cells treated with or without ERK1/2 inhibitor PD98059 or AP-1 inhibitor curcumin were determined. RESULTS: The RAW264.7 cells with high expression of adipophilin had higher levels of IL-6, MCP-1 and TNF-α, and higher protein levels of p-AP-1 and p-ERK1/2 than those in the cells with low expression of adipophilin. ERK1/2 inhibitor had no significant effect on the expression of adipophilin, but the protein expression of ERK1/2 and AP-1 was significantly inhibited (P<0.05). The administration of AP-1 inhibitor curcumin had no significant effect on the protein expression of adipophilin and ERK1/2, but the protein expression of AP-1 was significantly inhibited (P<0.05). At the same time, the releases of inflammatory factors IL-6, MCP-1 and TNF-α were significantly decreased. CONCLUSION: Adipophilin may regulate the expression of inflammatory factors through ERK1/2-AP-1 pathway in RAW264.7 macrophages.     

miR-451 inhibits inflammatory responses in glomerular mesangial cells by targeting Psmb8 in diabetic nephropathy mice

AIM: To investigate the effect of microRNA (miR)-451 by targeting proteasome subunit β type 8 (Psmb8) on the inflammatory responses in mouse glomerular mesangial cells (MCs) under high-and low-glucose conditions. METHODS: The expression levels of miR-451, IL-18 mRNA and TNF-α mRNA were detected by qPCR. The protein expression levels of IL-18, TNF-α and Psmb8 were determined by Western blot when miR-451 was over-expressed and down-expressed in the MCs. Moreover, the expression of IL-18 and TNF-α was detected when Psmb8 was silenced by si-Psmb8 in MCs. RESULTS: The expression of miR-451 was significantly decreased in the MCs treated with high glucose compared with low glucose group (P<0.01). However, the expression of Psmb8 was increased in high glucose group as compared with low glucose group (P<0.01). Moreover, the expression levels of Psmb8, IL-18 and TNF-α were significantly decreased when miR-451 was over-expressed in high glucose group (P<0.01). Additionally, the expression levels of IL-18 and TNF-α were significantly reduced when Psmb8 was silenced in the MCs under high glucose condition. CONCLUSION: miR-451 reduces the expression of inflammatory factors via targeting Psmb8 in the MCs under high glucose condition. Therefore, miR-451 may play a role in inflammation of diabetic nephropathy.     

Effects of macrophage polarization during development of liver cirrhosis in rats

AIM: To explore the state of macrophage polarization and its relation with intestinal endotoxemia-endoplasmic reticulum stress in the development of liver cirrhosis induced by multiple pathogenic factors in rats. METHODS: The male SD rats (n=36) were randomly divided into normal control group and liver cirrhosis model group, and sacrificed at the end of the 4th, 6th and 8th weeks. The rat model of liver cirrhosis was induced by multiple pathogenic factors. The levels of alanine aminotransferase (ALT), endotoxin, homocysteine (Hcy) in the plasma, and inducible nitric oxide synthase (iNOS), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), arginase-1 (Arg-1) and interleukin-10 (IL-10) in the liver tissues were detected by ELISA. Histopathological change of the liver was observed under microscope with the staining of hematoxylin and eosin (HE) and van Gieson (VG). The expression of glucose-regulated protein 78 (Grp78), nuclear factor-kappa B (NF-κB), interferon-regulatory factor 5 (IRF5), CD86, CD206 and transforming growth factor-β1 (TGF-β1) at mRNA levels in the liver tissues were detected by the method of real-time fluorescence quantitative PCR.RESULTS: Compared with the corresponding normal control group, the levels of ALT, endotoxin, Hcy in the plasma and Grp78 mRNA in the liver tissues in liver cirrhosis model group were significantly and gradually increased (P<0.05). The mRNA expression of NF-κB, IRF5 and CD86, and the protein levels of iNOS, TNF-α and IL-6 in the liver tissues were significantly increased (P<0.05), and they successively increased from the 4th week to the 6th week and decreased reversely at the 8th week. The mRNA expression of CD206, TGF-β1, Arg-1 and IL-10 in the liver tissues were significantly increased from the 6th week to the 8th week (P<0.05), and no significant difference at the 4th week was observed. The level of endotoxin in the plasma was correlated with the mRNA expression of Grp78 in the liver tissues (P<0.01). Both endotoxin in the plasma and Grp78 mRNA in the liver tissues were correlated with the mRNA expression of CD86 and CD206 in the liver tissues (P<0.01).CONCLUSION: The pathway of liver damage-intestinal endotoxemia-endoplasmic reticulum stress-macrophage polarization may be critical in the pathogenesis of liver cirrhosis induced by multiple pathogenic factors.     

IL-1β induces human mesangial cell injury via exacerbating lipid-induced endoplasmic reticulum stress

AIM：To investigate the molecular mechanism that interleukin-1 beta (IL-1β) exacerbates lipid-induced endoplasmic reticulum stress (ERS) and the injury of human mesangial cells (HMCs). METHODS：HMCs were cultured and divided into control group, low-density lipoprotein (LDL) group, IL-1β+LDL group and 4-phenyl butyric acid (4-PBA)+IL-1β+LDL group. Oil red O staining was used to evaluate the accumulation of lipid droplet in the cells. The mRNA levels of glucose-regulated protein 78(GRP78), protein kinase R-like endoplasmic reticulum kinase (PERK) and α-smooth muscle actin (α-SMA) were examined by real-time PCR. Immunocytochemistry was used to observe GRP78 expression. The protein level of NF-κB p65 was measured by Western blotting. The releases of IL-6 and TGF-β1 in the culture supernatants of HMCs were detected by ELISA. RESULTS：Compared with LDL group, the intracellular lipid accumulation, the mRNA levels of GRP78 and PERK, the protein expression of GRP78 and NF-κB p65, and the release of IL-6 were significantly increased in IL-1β+LDL group. Dramatically reduced intracellular lipid accumulation, down-regulated GRP78 and PERK mRNA expression, decreased protein levels of GRP78 and NF-κB p65, and suppressed IL-6 release were observed in 4-PBA+IL-1β+LDL group as compared with IL-1β+LDL group. The mRNA level of α-SMA was higher in IL-1β+LDL group than that in LDL group, and that in 4-PBA+IL-1β+LDL group was significantly depressed. CONCLUSION：IL-1β exacerbates lipid-induced ERS, thus promoting the injury of HMCs.