ABSTRACT
Aim To explore the role and mechanism of nuclear receptor subfamily 1,group D,member 1(NR1D1)in the proliferation and migration of mouse adventitial fibroblasts(AFs). Methods Primary AFs isolated from C57BL/6J mice were cultured. Adenovirus carrying Nr1d1 gene was used to overexpress NR1D1 in AFs. The expression of β-catenin was restored by SKL2001. Proliferating cell nuclear antigen(Ki-67)immunofluorescence staining and CCK-8 staining were used to determine cell proliferation,and scratch test was used to determine cell migration. qPCR was used to determine the mRNA level of Nr1d1. Western blot was used to determine the protein levels of NR1D1 and β-catenin. To investigate the role of NR1D1 in intimal hyperplasia,20 male wild type C57BL/6J mice were randomly divided into sham group,carotid artery endothelial injury,sham+SR9009(NR1D1 agonist)group and carotid artery endothelial injury+SR9009(n=5 in each group). They were treated with DMSO or SR9009(100 mg·kg-1·d-1)via intraperitoneal injection for 14 days after operation,respectively. The degree of carotid intimal hyperplasia was measured by HE staining 28 days after operation. Results NR1D1 overexpression significantly reduced the percentage of Ki-67-positive cells(P<0.01),total cell number(P<0.01)and slowed down the rate of wound-healing(P<0.01). NR1D1 overexpression significantly inhibited the expression of β-catenin(P<0.05). After the expression of β-catenin was restored by SKL2001,the inhibitory effects of NR1D1 overexpression on the proliferation and migration of AFs were abolished(P<0.01). Enhanced activity of NR1D1 significantly ameliorated intimal hyperplasia after carotid endothelial injury(P<0.01). Conclusion NR1D1 may inhibit the proliferation and migration of AFs via suppressing the expression of β-catenin.
ABSTRACT
Objective To investigate the effect of high glycolipid on mouse cardiac microvascular endothelial cells (MCMECs),clarify the role of Tom70 (translocase of the outer mitochondrial membrane 70,Tom70) in it,and explore the related mechanism.Methods MCMECs cultured with normal glucose medium were divided into normal glucose group (NG,5.5mmol/L),high glucose group (HG,25mmol/L) and HG combined with high fat group (HG+HF,glucose concentration 25mmol/L,500μmol/L,16h).Then,the expression of Tom70 in MCMECs was knocked down by siRNA,and the HG+HF group was further divided into vehicle group,Scramble siRNA group and Tom70-siRNA group.To further confirm the specific mechanism of Tom70 in MCMEC injury induced by high glycolipid,Tom70-siRNA group was subgrouped into N-acetylcysteine (NAC)-free group and NAG-containing group.Accordingly,the apoptosis levels were measured by flow cytometer,the generation of nitric oxide (NO) was detected by ELISA kit,the expressions of Tom70 were determined by immunofluorescence and qRT-PCR,and the levels of reactive oxygen species (ROS) by DHE staining and ELISA kit.Results The apoptosis level increased after exposure to HG,and the generation of NO decreased (P＜0.05),while merging HF could aggravate these injuries (P＜0.05).Moreover,HG inhibited the expressions of Tom70 and promoted the production of ROS in MCMECs (P＜0.05).Compared with HG alone,and combination with HF significantly inhibited the expression of Tom70,and significantly increased the production of ROS (P＜0.05).Most importantly,compared with the vehicle group and Scramble siRNA group,the intracellular ROS content and apoptosis rate increased in the Tom70-siRNA group,while generation of NO was significantly decreased (P＜0.01).In contrast,these damage effects mentioned above were partially reversed by the application of antioxidants NAC (P＜0.05).Conclusions High fat can further aggravate the damage on diabetic MCMECs and Tom70 could exert its effect against cardiac microvascular endothelial injury induced by diabetes via inhibiting oxidative stress.
ABSTRACT
Objective To investigate the protective role of GPR35 inhibition on hypoxic myocardial cell line and mouse myocardial infarction (MI) model.Methods For investigating the changes of GPR35 expression in hypoxic environment,the murine myocardial cells (MCM) were divided into normoxia group and hypoxia group,the mRNA expression of GPR35 was determined by q-PCR and the protein level was measured by Western blotting 6h after incubation.For further studying the role of GPR35,MCM were divided into four groups:normoxia,hypoxia,hypoxia+vehicle,hypoxia+CID2745678 (GPR35 inhibitor,3μmol/L) group.Accordingly,the apoptosis of cardiomyocytes was measured by flow cytometer and TUNEL.For investigating the changes of GPR35 expression in the state of myocardial ischemia,the C57 male mice were divided into sham group (n=6) and MI group (n=8),the mRNA expression of GPR35 was determined by q-PCR and the protein level was measured by Western blotting 3 days after MI.For further studying the role of GPR35,the C57 mice were divided into four groups:sham (n=6),MI (n=8),MI+vehicle (n=8) and MI+CID2745678 (n=8) group.Ultrasound echocardiography was performed 4 weeks after MI.Mice were then sacrificed and the hearts were removed and stained with Masson to measure the myocardial fibrosis area.Results Compared with normoxia group,the levels of GPR35 mRNA and protein increased obviously in hypoxia group (P＜0.01,P＜0.05);Compared with hypoxia+vehicle group,the myocardial cells apoptosis in hypoxia+CID2745678 group decreased markedly (P＜0.05).Three days after MI,compared with the sham group,the levels of GPR35 mRNA and protein increased obviously (P＜0.01,P＜0.05) in MI group;Compared with MI+vehicle group,the left ventricular fraction shortening (LVFS) and left ventricular ejection fraction (LVEF) relieved obviously (P＜0.05) and myocardial fibrosis level declined markedly in MI+CID2745678 group (P＜0.05).Conclnsion Inhibition of GPR35 could decrease the apoptosis of cardiomyocytes cultured in hypoxia and attenuated the injury of myocardial ischemia.