Effect of miR-22 secreted by macrophage exosomes on cardiomyocyte autophagy under uremic toxin stimulation

AIM To investigate the effect of microRNA-22 (miR-22) secreted by macrophage exosomes on the autophagy of H9c2 cardiomyocytes under uremic toxin stimulation. METHODS The macrophage-derived exosomes stimulated by indoxyl sulfate (IS) were collected and co-cultured with H9c2 cells. The levels of miR-22 in the macrophages, macrophage-derived exosomes and H9c2 cells were detected by RT-qPCR. The viability of H9c2 cells was measured by CCK-8 assay. The expression of exosome surface marker protein CD63 and autophagy-related proteins LC3 and P62 was determined by Western blot. RESULTS Under IS stimulation, the expression of exosome surface marker protein CD63 in the macrophages was significantly higher than that in control group (P<0.05), and the levels of miR-22 in the macrophages and macrophage-derived exosomes were significantly increased (P<0.01). With the increase in macrophage exosome concentration, the viability of H9c2 cells was decreased gradually (P<0.05), and the stimulation of macrophage exosomes reduced P62 expression and promoted the conversion of LC3-I to LC3-II in a dose-dependent manner (P<0.05). Macrophage-derived exosomes increased the ratio of LC3-II to LC3-I but decreased P62 protein expression in the H9c2 cells transfected with miR-22 mimic compared with the cells transfected with corresponding negative control miRNAs (P<0.05). However, miR-22 inhibitor yielded contrasting results. CONCLUSION IS-stimulated macrophages increase expression of miR-22 in cardiomyocytes through exosomes, and promote autophagy of the cardiomyocytes.     

Effects of P38 MAPK signaling pathway on anacardic acid attenuating mouse cardiomyocyte hypertrophy induced by phenylephrine

AIM: To investigate the roles of P38 mitogen-activated protein kinase (P38 MAPK) in the process of anacardic acid (AA) attenuating mouse cardiomyocyte hypertrophy induced by phenylephrine (PE). METHODS: Cardiomyocyte hypertrophy was induced by PE in primary neonatal mouse myocardial cells. According to random number table method, the experiments were designed in 6 groups as following: control group, PE+ DMSO group, PE group, PE+ AA group, PE+ AA+ P38 inhibitor group and PE+ P38 inhibitor group. Mouse myocardial cells were collected after intervention for 48 h. The protein levels of p-P38, acetylated histone H3 at lysine 9 (H3K9ac) and atrial natriuretic peptide (ANP) were determined by Western blot. The interaction between p-P38 and H3K9ac was verified by co-immunoprecipitation (Co-IP). The mRNA expression of myocyte enhancer factor 2C (MEF2C) were tested by RT-qPCR. Mouse myocardial cell surface area was observed by immunofluorescence staining. RESULTS: The results of Western blot showed that the protein levels of p-P38 and H3K9ac in PE group were significantly increased compared with control group (P<0.05), and the levels of MEF2C mRNA and ANP protein in PE group were apparently increased compared with control group (P<0.05). However, P38 inhibitor and histone acetylase inhibitor AA attenuated P38 phosphorylation and H3K9 acetylation induced by PE, and down-regulated the over-expression of MEF2C and ANP in the mouse myocardial cells (P<0.05). The results of immunofluorescence staining showed that PE apparently increased mouse myocardial cell surface area (P<0.05), while P38 inhibitor and AA attenuated cardiomyocyte hypertrophy induced by PE (P<0.05). CONCLUSION: The mechanism of AA attenuating cardiomyocyte hypertrophy induced by PE may be related to the regulation of histone acetylation modification imbalance mediated by P38 MAPK signaling pathway.     

circRNA-42398 inhibits activation of hepatic stellate cells via TGF-?β1/Smads signaling pathway modulation

AIM To study the effect of mouse circular RNA-42398 (mmu_circ_42398) over-expression on the activation of hepatic stellate cells. METHODS Mouse hepatic stellate JS1 cells were cultured and randomly divided into control group, vector group and mmu_circ_42398 over-expression group.mmu_circ_42398 over-expression plasmid vector was constructed, and then transiently transfected into JS1 cells using Lipofectamine 2000. The cells were collected 48 h after transfection. Expression of mmu_circ_42398 was detected by RT-qPCR.The backsplice site of PCR products was verified by sequencing. The protein levels of α-smooth muscle actin (α-SMA), collagen type I （Col I), transforming growth factor β1(TGF-β1), Smad2, Smad3, p-Smad2 and p-Smad3 in the cells were determined by Western blot. RESULTS RT-qPCR results showed that the expression of mmu_circ_42398 was significantly increased after mmu_circ_42398 over-expression vector was transiently transfected into the JS1 cells (P<0.01). The protein expression levels of α-SMA and Col I were significantly decreased(P<0.01), and the phosphorylation levels of Smad2 and Smad3 were decreased significantly in mmu_circ_42398 over expression group (P<0.01). However, the protein expression levels of TGF-β1, Smad2 and Smad3 had no significant change (P>0.05). CONCLUSION mmu-circ-42398 inhibits the activation of hepatic stellate cells via TGF-β1/Smads signaling pathway modulation.     

Effects of different active constituents of Gynostemma pentaphyllum on mitochondrial energy metabolism-related proteins in endothelial cells induced by ox-LDL

AIM To investigate the effects of different components of Gynostemma pentaphyllum ［gypenosides (Gps), gypenoside XLIX (GpXLIX) and ginsenoside Rb3 (GRb3)］ on mitochondrial energy metabolism-related proteins in endothelial cells induced by oxidized low-density lipoprotein (ox-LDL). METHODS EA.hy926 cells were divided into control group, model group, Gps group, GpXLIX group and GRb3 group. The cells in control group were cultured only in DMEM complete medium. The cells in model group were treated with 100 mg/L ox-LDL for 48 h. The cells in Gps group, GpXLIX group and GRb3 group were treated with 100 mg/L ox-LDL for 24 h, and then treated with Gps, GpXLIX and GRb3 at 100 mg/L for another 24 h, respectively. The ATP content in each group was detected by ELISA. The expression levels of mitochondrial energy metabolism-related proteins, cytochrome C oxidase subunit 5a （Cox5a）, NADH:ubiquinone oxidoreductase core subunit S1 （Ndufs1）, ATP synthase F1 subunit alpha (ATP5a) and cytochrome C (Cyt C）, were determined by Wes automatic Western blot quantitative analysis system and Western blot. RESULTS Compared with control group, the ATP content in model group was decreased (P<0.01). After drug intervention, the ATP content increased to different degrees in Gps group, GpXLIX group and GRb3 group (P<0.01). The results of Wes automatic Western blot quantitative analysis system were consistent with those of Western blot. These results showed that compared with control group, the protein expression of Cox5a, Ndufs1 and ATP5a in model group was decreased, and the protein expression of Cyt C was increased (P<0.01). After intervention, the protein expression of Cox5a, Ndufs1 and ATP5a was increased and the protein expression of Cyt C was decreased in Gps group, GpXLIX group and GRb3 group (P<0.05 or P<0.01). Among them, the effect of Gps on the protein expression of Cox5a, Ndufs1 and Cyt C was significantly stronger than those of the 2 monomer components, and the effect of GRb3 was found to be superior in the 2 monomer components. The effect of GpXLIX on ATP5a protein was superior to the other 2 components. CONCLUSION Gynostemma total saponins and related active ingredients protect ox-LDL-induced endothelial cells by affecting mitochondrial energy metabolism-related proteins, thereby preventing and treating atherosclerosis.     

Expression relevance of GATA-1 and miR-451a in erythroid differentiation of K562 cells under hypoxia

AIM To investigate the expression relevance of GATA binding protein-1 (GATA-1) and microR?NA-451a (miR-451a) in erythroid differentiation of human chronic myeloid leukemia K562 cells under hypoxia. METHODS The K562 cells were divided into 2 groups: normoxia group and hypoxia (1% O₂) group, and 40 μmol/L hemin chloride was used to induce K562 cell differentiation for 48 and 72 h. The mRNA expression of γ-globin was detected by RT-qPCR, hemoglobin production was observed by benzidine staining, and flow cytometry was used to detect CD235a expression for verifying erythroid differentiation model. The protein expression of GATA-1 during K562 cell differentiation under normoxia and hypoxia was determined by Western blot. RT-qPCR was used to detect the mRNA expression of GATA-1 and the expression level of miR-451a, and their correlation was analysis. The K562 cells were infected by lentivirus for over-expression or knock-down of GATA-1. Meanwhile, the morphological changes of the cells in the above groups were analyzed by Wright-Giemsa staining method to clarify the erythroid differentiation of K562 cells. The expression miR-451a was detected by RT-qPCR after GATA-1 over-expression or knock-down. REULTS: Under normoxia and hypoxia conditions, the expression levels of γ?-globin and CD235a and the positive rate of benzidine staining at 48 and 72 h were significantly higher than those at 0 h (P<0.05).At 72 h, the expression levels of γ?-globin and CD235a and the benzidine staining positive rate in hypoxia group were significantly higher than normoxia group (P<0.05). The expression of GATA-1 mRNA and miR-451a under hypoxia showed an upward trend during the erythroid differentiation of K562 cells, and was significantly higher than that in normoxia group at 72 h (P<0.05). Correlation analysis showed that the mRNA expression of GATA-1 was positively correlated with miR-451a expression under hypoxia (P<0.01). After over-expression of GATA-1 under hypoxia, the expression of γ-globin and CD235a, the positive rate of benzidine staining, and the cell counts of size augmentation, nuclear deflection and nuclear shrinkage at 72 h were significantly higher than those in negative control group (P<0.05). After knock-down of GATA-1 under hypoxia, the expression of γ-globin and CD235a, the benzidine staining positive rate, and the cell counts of size augmentation, nuclear deflection and nuclear shrinkage at 72 h were significantly lower than those in negative control group (P<0.05). Compared with negative control group under hypoxia, the expression of miR-451a was significantly increased after GATA-1 over-expression (P<0.05), while the expression of miR-451a was significantly decreased after GATA-1 knock-down (P<0.05). CONCLUSION Hypoxia increases the expression of GATA-1 and then up-regulates miR-451a to promote erythroid differentiation of K562 cells.     

SUMO-specific protease 3 aggravates CaPO4-induced mouse abdominal aortic aneurysm formation by promoting macrophage polarization

AIMTo investigate the role of SUMO-specific protease 3 (SENP3) in macrophage polarization and calcium phosphate (CaPO₄)-induced abdominal aortic aneurysm (AAA) formation in mice. METHODS（1） Bone marrow-derived monocytes (BMDMs) in Senp3^flox/flox (wild-type, WT) mice and Senp3^flox/flox; Lyz2-Cre (monocyte-specific SENP3 knockout, i.e. conditioned knockout, cKO) mice were isolated and induced for M1 and M2 polarization. The mRNA and protein expression level of SENP3 were detected by RT-qPCR, Western blot and immunocytofluorescence, and the differential distribution of M1/M2 BMDMs from WT and cKO mice was analyzed. （2） CaPO₄ was administrated to induce AAA model in 8~12-week-old male WT and cKO mice. The AAA incidence, survival rate and maximal aortic diameter were analyzed between the 2 groups. Aortic aneurysm tissues were collected for pathological analysis, and the expression levels of SENP3, interleukin-1β (IL-1β), tumor necrosis factor-α (TNFα), IL-6 and matrix metalloproteinases-9 (MMP-9) were measured by RT-qPCR and Western blot. Dihydroethidium staining in situ in frozen sections was used to analyze the production of reactive oxygen species (ROS). （3） To explore the potential mechanisms, Western blot and co-immunoprecipitation were used to verify the de-SUMO modification of mitogen-activated protein kinase kinase 7 (MKK7) induced by SENP3. Besides, BMDMs were transfected with Flag-MKK7 wild type (Flag-MKK7 WT) and SUMO-modified site K18 mutant (Flag-MKK7 K18R mutant), and then M1 polarization of the cells was induced. The protein levels of p-JNK and MMP-9 in the 2 groups were determined by Western blot. RESULTS(1) SENP3 expression was up-regulated in M1 polarized macrophages (P<0.01), but was down-regulated in M2 polarized macrophages (P<0.01). The expression of SENP3 was decreased during the transformation of M1 to M2 in the macrophages (P<0.01), but was significantly up-regulated during the opposite process (P<0.01). Besides, more M1 macrophages and less M2 macrophages after induction were observed in the BMDMs from cKO mice than those from WT mice. (2) SENP3 expression was up-regulated in AAA tissues (P<0.05). The AAA incidence of cKO mice was significantly reduced after CaPO₄ induction (P<0.01), the survival rate was significantly improved (P<0.05), and maximal aortic diameter was significantly reduced in cKO group (P<0.01). The levels of IL-1β, IL-6 and TNFα, and the production of ROS were significantly down-regulated (P<0.01), meanwhile MMP-9 expression was also down-regulated in cKO mice (P<0.05). (3) the SUMO2/3 modification of MKK7 was reduced during M1 polarization, and MKK7 interaction with SENP3 was enhanced. Significantly up-regulated protein level of p-JNK and MMP-9 were verified in the M1 macrophages transfected with Flag-MKK7 K18R mutant (P<0.05). CONCLUSION SENP3 activates the MAPK/JNK pathway via de-SUMOylation of MKK7, regulates the M1/M2 polarization of macrophages and promotes the protein level of MMP-9, thus aggravating AAA formation.     

Mangiferin attenuates hypoxia/reoxygenation-induced injury of human myocardial cells

AIM To investigate the effect of mangiferin on hypoxia/reoxygenation (H/R)-induced injury of human myocardial cells and its mechanism. METHODS Human myocardial AC16 cells were divided into normal group, H/R group and H/R + mangiferin (50, 100 and 200 μmol/L) treatment groups. The mRNA and protein expression levels of Kelch-like epichlorohydrin-associated protein-1 (Keap-1), Bax, Bcl-2, caspase-3, caspase-9 and superoxide dismutase 2 (SOD2) were detected by RT-qPCR and Western blot, respectively. The protein expression of nuclear factor E2-related factor 2 (Nrf-2) in nucleus was determined by Western blot. The expression of microRNA-432-3p (miR-432-3p) was detected by RT-qPCR. The generation of reactive oxygen speciess (ROS) in the cells was measured by DCFH-DA probing. The cell viability was measured by CCK-8 assay. Apoptosis was analyzed by flow cytometry. RESULTS No significant difference in the expression of miR-432-3p and Keap-1 between normal group and H/R group was observed. Compared with normal group, the nuclear translocation of Nrf-2, the ROS level, and the mRNA and protein expression of Bax, caspase-3 and caspase-9 were significantly increased in H/R group （P<0.05）. The mRNA and protein expression of SOD2 and Bcl-2, and the cell viability significantly decreased in H/R group compared with normal group, while the apoptosis was increased significantly （P<0.05）. Treatment with mangiferin resulted in an increase in the miR-432-3p expression and a decrease in the ROS level, and the expression of Keap-1, Bax, caspase-3 and caspase-9 was also inhibited as compared with H/R group （P<0.05）. The Nrf-2 nuclear translocation, and the protein levels of SOD2 and Bcl-2 in mangiferin treatment groups were significantly increased as compared with H/R group （P<0.05）. The cell viability was increased significantly, and the apoptosis was decreased significantly in mangiferin treatment groups as compared with H/R group （P<0.05）. The effects of mangiferin in middle- and high-dose groups were better than those in low-dose group, and no significant difference between middle- and high-dose groups was found. CONCLUSION Mangiferin inhibits the decrease in myocardial cell viability and the apoptosis induced by H/R injury. The mechanism may be related to the up-regulation of Nrf-2 antioxidant stress effect via enhancing the expression of miR-432-3p.     

Effect of andrographolide on osteosarcoma 143B cells and its mechanism

AIM To investigate the inhibitory effect of andrographolide （AG） on human osteosarcoma 143B cells and its underlying molecular mechanism. METHODS Osteosarcoma 143B cells were cultured in vitro and treated with AG at different concentrations (0~20 μmol/L), and the effect of AG on the proliferation of 143B cells was determined by crystal violet staining, MTT assay and colony formation assay. The wound-healing assay was performed to detect the migration ability of osteosarcoma 143B cells. Transwell assay was performed to analyze the invasive capacity of osteosarcoma 143B cells. The effect of AG on the apoptosis of osteosarcoma 143B cells was detected by Hoechst 33258 staining and flow cytometry. After treatment with of AG at different concentrations, the protein levels of the molecules related to proliferation, migration, invasion and apoptosis of osteosarcoma 143B cells were determined by Western blot. The expression of β-catenin and its related molecule c-Myc in the Wnt signaling pathway was analyzed by Western blot. RESULTS Compared with blank group, the proliferation, migration and invasion of osteosarcoma 143B cells in AG treatment group were significantly inhibited (P<0.05) in a concentration-dependent manner. The expression levels of invasion- and migration-related proteins matrix metalloproteinase-9 (MMP-9), vimentin and Snail were all down-regulated (P<0.05). AG also increased the expression of antiapoptotic protein Bcl-2, and the levels of apoptosis-related protein caspase-3 was decreased but cleaved caspase-3 was increased. At the same time, the expression levels of Wnt/β-catenin signaling pathway related proteins β-catenin and c-Myc were significantly decreased (P<0.05). CONCLUSION Andrographolide may inhibit the proliferation, migration, and invasion of osteosarcoma 143B cells and promote their apoptosis by inhibiting the activity of Wnt signaling pathway.     

Effect of Herba Taxilli extracts combined with miR-375 on viability and apoptosis of osteoarthritic chondrocytes

AIM To study the effects of extracts of Herba Taxilli (Sangjisheng, SJS) on the viability and apoptosis of osteoarthritic chondrocytes and the underlying mechanism. METHODS Human primary osteoarticular chondrocytes (RPOC) were divided into control group, interleukin-1β (IL-1β) group, IL-1β+low-dose extracts of SJS (SJS-L) group, IL-1β+medium-dose extracts of SJS (SJS-M) group, IL-1β+high-dose extracts of SJS (SJS-H) group, IL-1β+anti-miR-NC group, IL-1β+anti-miR-375 group, IL-1β+SJS-H+miR-NC group, IL-1β+SJS-H+miR-375 group. The cell viability was measured by MTT assay, apoptosis was analyzed by flow cytometry, miR-375 expression was detected by qPCR, and the protein levels of cyclin D1, P21, Bcl-2, Bax and caspase-3 were determined by Western blot. RESULTS Compared with control group, the viability of RPOC at 24 h, 48 h and 72 h and the protein expression levels of cyclin D1 and Bcl-2 were significantly decreased (P<0.05), the protein levels of P21, Bax and caspase-3, the apoptotic rate and the expression level of miR-375 were remarkably increased in IL-1β group(P<0.05). Compared with IL-1β group, the cell viability at 24 h, 48 h and 72 h and the protein expression of cyclin D1 in the RPOC were greatly increased (P<0.05), while the expression of P21 was significantly decreased in IL-1β+SJS-M group and IL-1β+SJS-H group(P<0.05).The apoptotic rate, Bax, caspase-3 protein and miR-375 expression were obviously decreased (P<0.05), and Bcl-2 protein level was significantly increased in IL-1β+SJS-H group compared with IL-1β group(P<0.05). Compared with IL-1β+anti-miR-NC group, the expression of miR-375, the protein levels of P21, Bax, caspase-3 and the apoptotic rate in the RPOC of IL-1β+anti-miR-375 group were markedly decreased (P<0.05), while the cell viability at 24 h, 48 h and 72 h and the protein levels of cyclin D1 and Bcl-2 were significantly increased (P<0.05). Over-expression of miR-375 reversed the effects of extracts of SJS on the viability and apoptosis of RPOC with IL-1β stimulation. CONCLUSION The extracts of Herba Taxilli promotes the viability and inhibits apoptosis of RPOC treated with IL-1β, which is related to the regulation of miR-375 expression.     

Procaine regulates CXCR7 and affects AKT/STAT3 signaling pathway to inhibit viability,migration and invasion of bladder cancer cells

AIM To investigate the effects of procaine (PCA) and CXC chemokine receptor 7 (CXCR7) on the viability, migration and invasion of bladder cancer cells and its potential mechanism. METHODS Human bladder cancer RT4 cells were treated with PCA at different concentrations, and were divided into PBS group (without PCA treatment), PCA group (treated with 4 mmol/L PCA), siRNA negative control (si-Con) group (transfected with si-Con), CX?CR7 siRNA (si-CXCR7) group (transfected with si-CXCR7), PCA+pcDNA group (treated with 4 mmol/L PCA and transfected with pcDNA) and PCA+pcDNA-CXCR7 group (treated with 4 mmol/L PCA and transfected with pcDNA-CX?CR7). The siRNA and pcDNA were transfected into the RT4 cells by liposome method. The mRNA expression of CX?CR7 in the RT4 cells was detected by RT-qPCR. The cell viability was measured by CCK-8 assay. The invasion and migration abilities of the cells were detected by Transwell assays. The protein levels of CXCR7, AKT, STAT3, p-AKT and p-STAT3 were determined by Western blot . RESULTS Compared with PBS group, the viability, migration ability and invasion ability of the RT4 cells treated with PCA at different concentrations were significantly decreased (P<0.05), and the expression of CXCR7 at mRNA and protein levels in PCA group was also significantly decreased (P<0.05). Compared with si-Con group, the expression of CXCR7 at mRNA and protein levels in si-CXCR7 group was significantly decreased, and the viability, migration ability and invasion ability of the cells were also significantly decreased (P<0.05). Compared with PCA+pcDNA group, the expression of CXCR7 at mRNA and protein levels in PCA+pcDNA-CXCR7 group was significantly increased, and the viability, migration ability and invasion ability of the cells were also significantly increased (P<0.05). Compared with PBS group, the protein levels of p-AKT and p-STAT3 in PCA group were significantly decreased(P<0.05). Compared with PCA+pcDNA group, the protein levels of p-AKT and p-STAT3 in PCA+pcDNA-CX?CR7 group were significantly increased (P<0.05). No significant difference in the protein levels of AKT and STAT3 among the groups was observed. CONCLUSION Treatment with PCA inhibits the viability, migration and invasion of bladder cancer cells by inhibiting the expression of CXCR7. Over-expression of CXCR7 reverses this effect of PCA. Its mechanism may be related to AKT/STAT3 signaling pathway.     

Effect of lncRNA FEZF1-AS1 on viability and apoptosis of LPS-induced vascular endothelial cells by regulating miR-363-3p expression

AIM To investigate the mechanism of long noncoding RNA （lncRNA） FEZF1-AS1 regulating microRNA-363-3p （miR-363-3p） on the viability and apoptosis of lipopolysaocharide （LPS）-induced vascular endothelial cells. METHODS Human umbilical vein endothelial cells （HUVECs） were cultured in vitro. pcDNA-NC, pcDNA-FEZF1-AS1, anti-miR-NC, anti-miR-363-3p, miR-NC and miR-363-3p mimics were transfected into the HUVECs and LPS stimulation was applied for 24 h. RT-qPCR was used to detect the expression of FEZF1-AS1 and miR-363-3p. The cell viability was measured by MTT assay. The apoptotic rate was analyzed by flow cytometry. The dual-luciferase reporter experiment was used to verify the targeted regulation of FEZF1-AS1 and miR-363-3p. Western blot was used to determined the expression of cyclin D1, Ki67 and cleaved caspase-3. RESULTS Compared with control group, the expression level of FEZF1-AS1 in LPS group was significantly reduced （P<0.05）, and the expression level of miR-363-3p was significantly increased （P<0.05）. Compared with pcDNA-NC+LPS group, the cell viability in pcDNA-FEZF1-AS1+LPS group was significantly increased （P<0.05）, the apoptotic rate was significantly reduced （P<0.05）, the protein levels of cyclin D1 and Ki67 were significantly increased （P<0.05）, and the protein level of cleaved caspase-3 was significantly reduced （P<0.05）. Compared with anti-miR-NC+LPS group, the cell viability in anti-miR-363-3p+LPS group was significantly increased （P<0.05）, the apoptotic rate was significantly reduced （P<0.05）, the protein levels of cyclin D1 and Ki67 were significantly increased （P<0.05）, and the protein level of cleaved caspase-3 was significantly reduced （P<0.05）. Dual-luciferase reporter experiment confirmed that FEZF1-AS1 targeted miR-363-3p. Compared with miR-NC+pcDNA-FEZF1-AS1+LPS group, the cell viability in miR-363-3p+pcDNA-FEZF1-AS1+LPS group was significantly reduced （P<0.05）, the apoptotic rate was significantly increased （P<0.05）, the protein levels of cyclin D1 and Ki67 were significantly reduced （P<0.05）, and the protein level of cleaved caspase-3 was significantly increased （P<0.05）. CONCLUSION Over-expression of FEZF1-AS1 promotes the viability and inhibits apoptosis of LPS induced vascular endothelial cells by inhibiting the expression of miR-363-3p.     

Role of CRIF1 in cardiomyocyte apoptosis induced by palmitic acid

AIM: To investigate the effects of CR6-interacting factor 1 (CRIF1) on the apoptosis of mouse cardiomyocytes (MCMs) induced by palmitic acid. METHODS: The MCMs cultured with medium containing palmitic acid at 0 and 300 μmol/L for 24 h were divided into control group and palmitic acid group, respectively. In order to explore the effects of CRIF1 on MCMs injuries induced by high fat, MCM exposed to palmitic acid at 300 μmol/L for 24 h were divided into vehicle group, scrambled (Scra) siRNA group and CRIF1 siRNA group. The cells in vehicle group were only treated with transfection reagent, the cells in Scra siRNA group were given a treatment with transfection reagent and scrambled RNA, and the cells in CRIF1 siRNA group were given a treatment with transfection reagent and CRIF1 specific siRNA. In order to further confirm the specific mechanism of CRIF1 in high fat-induced MCM injuries, MCMs in CRIF1 siRNA group were divided into DMSO group and N-acetyl cysteine (NAC) group, and were given the same intervention of palmitic acid. RT-qPCR, Western blot and immunofluorescence staining were used to detect the mRNA and protein expression of CRIF1. The apoptotic rate was analyzed by flow cytometry, and the level of intracellular reactive oxygen species (ROS) was tested by DHE staining and ELISA. RESULTS: The expression of CRIF1 was significantly increased after exposure to palmitic acid (P<0.05). Compared with control group, the apoptotic rate was increased significantly in vehicle group and Scra siRNA group (P<0.05). The apoptotic rate was significantly increased in CRIF1 siRNA group (P<0.05). Compared with control group, the intracellular ROS content was significantly increased in vehicle group and Scra siRNA group (P<0.05). Compared with vehicle group and Scra siRNA group, the intracellular ROS content was significantly increased in CRIF1 siRNA group (P<0.05). Compared with DMSO group, the intracellular ROS content and the apoptotic rate were remarkably decreased in NAC group (P<0.05). CONCLUSION: With the inhibition of oxidative stress, CRIF1 may reduce the apoptosis of MCMs induced by high fat.     

A study on the mechanism of doxorubicin promoting IL-1β and collagen type I secretion in cardiac fibroblasts

AIM To observe the effect of adriamycin/doxorubicin （DOX） on the production of inflammatory cytokines and collagen in cardiac fibroblasts and its mechanism. METHODS Neonatal SD rat cardiac fibroblasts were isolated, cultured, and identified by immunofluorescence staining with monoclonal antibodies against vimentin observed under a confocal laser-scanning microscope. The Cell Counting Kit-8 assay was used to detect the toxicity of DOX on cardiac fibroblasts, and flow cytometry with annexin V-FITC/PI double staining was used to detect apoptosis. ELISA was used to detect the release of inflammatory factors in the supernatant of cultured cells. Immunofluorescence labeling assay was used to detected α-smooth muscle actin （α-SMA） expression and mitochondrial reactive oxygen species （mROS） in the cells. Western blot was used to detect the expression of nucleotide-binding oligomerization domain-like receptor protein 3 （NLRP3） inflammasome-related proteins in cardiac fibroblasts. RESULTS （1） Compared with the control group, DOX inhibited the proliferation of cardiac fibroblasts （P<0.05）, but had no significant effect on apoptosis （P>0.05）. （2） Treatment with DOX promotes the release of proinflammatory factors interleukin-1β （IL-1β） and IL-6 in cardiac fibroblasts （P<0.05）. （3） The expression of α-SMA, collagen type I and transforming growth factor-β in DOX treatment group increased significantly compared with control group （P<0.05）. （4） Compared with the control group, the levels of mROS, cellular NLRP3 and cleaved caspase-1 in cardiac fibroblasts increased significantly after DOX treatment. CONCLUSION Doxorubicin promotes cardiac fibroblasts to secrete IL-1β and collagen type I by promoting mROS production and activating NLRP3 inflammasome.     

Effect of wogonoside on inflammatory response in mice with viral myocarditis induced by Coxsackie virus B3

AIM: To investigate the effect of wogonoside on the inflammatory response of mice with Coxsackie virus B3 (CVB3)-induced myocarditis and its possible regulatory mechanism. METHODS: A mouse model of viral myocarditis was constructed by infecting BALB/c mice with CVB3. BALB/c mice (n=40) were randomized into 4 groups: normal group, CVB3-induced viral myocarditis group, CVB3-induced viral myocarditis combined with wogonoside treatment group and CVB3-induced viral myocarditis combined with wogonoside plus AKT agonist treatment group. All the mice were sacrificed 7 days after treatment. In the first 3 groups, HE staining was applied to detect the infiltration of inflammatory cells in the myocardium, ELISA was applied to detect the serum levels of interleukin-1β (IL-1β) and IL-6, while Western blot was applied to detect the protein expression of inflammatory factors and the activation of AKT/NF-κB pathway. Inaddition, the activation of AKT/NF-κB pathway in the 4 groups was detected by Western blot analysis. RESULTS: HE staining showed that there was a large amount of inflammatory cell infiltration in the myocardium of CVB3-induced viral myocarditis mice, as compared with the normal group, which was significantly reduced by wogonoside treatment (P<0.05). The serum levels of IL-1β and IL-6 in the mice after CVB3 infection were significantly higher than those in normal group (P<0.05), which was also significantly reduced by wogonoside treatment (P<0.05). Western blot analysis indicated that wogonoside treatment significantly reduced the expression of inflammatory factors IL-1β and IL-6, and the phosphorylation of AKT/NF-κB pathway-related proteins in the myocardial tissue (P<0.05). After administration of AKT agonist, the inhibitory effect of wogonoside on NF-κB phosphorylation and inflammatory factors expression was significantly eliminated (P<0.05). CONCLUSION: Wogonoside attenuates the inflammatory response of mice with viral myocarditis by inhibiting the AKT/NF-κB pathway.     

NKT cells inhibit Ang II-induced phenotypic transformation of mouse vascular smooth muscle cells by down-regulating PDGFRβ

AIM To investigate the role of natural killer T (NKT) cells in the phenotypic transformation of vascular smooth muscle cells induced by hypertension in mice. METHODS The hypertension model in wild-type and CD1d gene knockout mice was established by continuous infusion of angiotensin II (Ang II) at a dose of 490 ng·kg^-1·min^-1 for 14 d, and the NKT cell specific agonist α-galactosylceramide (α-GC) was given at a dose of 100 μg/kg in wild-type mice. The blood pressure of the mice was monitored by non-invasive tail cuff method. The thickness of aortic wall was measured by HE staining, and the degree of aortic fibrosis was observed by Masson staining. The expression levels of α-smooth muscle actin (α-SMA), osteopontin (OPN) and platelet-derived growth factor receptor β (PDGFRβ) in aortic tissue were detected by Western blot. RESULTS Compared with control group, the blood pressure, the aortic wall thickness, the degree of aortic fibrosis, the secretory marker protein OPN expression and the PDGFRβ expression were all increased significantly after infusion of Ang II for 14 d (P<0.05), while the expression of contractile marker protein α-SMA was decreased (P<0.05). The above changes were aggravated after CD1d gene knockout (P<0.05), but were attenuated after administration of α-GC (P<0.05). CONCLUSION NKT cells reduces Ang II-induced phenotypic transformation of mouse vascular smooth muscle cells by reducing the expression of PDGFRβ, increasing the expression of contractile protein and decreasing the expression of secretory protein.     

Ligustilide inhibits angiogenesis and epithelial-mesenchymal transition in human hemangioendothelial cells by reducing VEGF levels

AIM To investigate the effect of ligustilide on human hemangioendothelial cells (HemECs) and to analyze its mechanism. METHODS The effect of ligustilide at different concentrations on the viability of HemECs was measured by CCK-8 assay. The HemECs were divided into control group and ligustilide （10, 25 and 50 μmol/L） treatment groups, and the proliferation of HemECs was detected by EdU staining. The effects of ligustilide on the angiogenesis of HemECs was tested by microtubule formation experiment. The protein expression of vascular endothelial growth factor (VEGF) and epithelial-mesenchymal transition (EMT)-related markers in HemECs cells was determined by Western blot. RESULTS There was no significant difference in the viability of the cells treated with ligustilide at the concentrations between 0.1~50 μmol/L compared with control cells. Compared with control group, ligustilide at 25 and 50 μmol/L significantly reduced the number of EdU-positive cells and microtubule-like structures (P<0.05), reduced the protein expression level of VEGF (P<0.05), increased the protein expression of E-cadherin, and decreased the protein expression of vimentin and β-catenin (P<0.05). Compared with control group, the expression of VEGF and vimentin was significantly up-regulated, and the protein expression of E-cadherin was significantly down-regulated in VEGF overexpression group (P<0.05). Compared with VEGF overexpression group, the expression of VEGF and vimentin in 50 μmol/L ligustilide-treated VEGF-overexpressing cells were significantly reduced (P<0.05), and the protein expression of E-cadherin was significantly increased (P<0.05). CONCLUSION Ligulide inhibits the proliferation of HemECs, and also inhibits the angiogenesis and EMT process of HemECs by reducing the level of VEGF.     

Inhibitory effect of Wendan decoction on formation of foam cells induced by ox-LDL

AIM To explore the anti-atherosclerotic mechanism of Wendan decoction based on formation of foam cells. METHODS The optimal concentrations of Wendan decoction without cytotoxity to cells were selected by MTT assay. After Wendan decoction treatment, the formation of foam cells was examined by oil red O staining. The cholesterol efflux, cholesterol level, free cholesterol level and cholesterol esterification rate were analyzed using cholesterol efflux assay, total cholesterol assay and free cholesterol assay. The expression levels of macrophage membrane proteins, including CD36, scavenger receptor class A （SR-A）, ATP-binding cassette transporter A1 （ABCA1） and scavenger receptor class B type I （SR-BI）, were quantified by Western blot. RESULTS The optimal concentrations of Wendan decoction without cytotoxity to the cells were 0~6 g/L. Wendan decoction at the concentrations of 1.5, 3 and 6 g/L were selected for the experiments. Wendan decoction at these concentrations inhibited the formation of foam cells induced by oxidized low-density lipoprotein （ox-LDL）, and reduced the accumulation of intracellular lipids in a concentration-dependent manner （P<0.05 or P<0.01）. Wendan decoction also reduced intracellular total cholesterol level, cholesterol ester level and cholesterol esterification rate （P<0.05 or P<0.01）, promoted efflux of intracellular cholesterol （P<0.01）, and decreased the protein level of CD36 in THP-1 cell-derived macrophages （P<0.01） in a concentration-dependent manner. Wendan decoction at the concentration of 6 g/L significantly reduced the protein level of SR-A in THP-1 cell-derived macrophages （P<0.05）. At the concentrations of 3 and 6 g/L, Wendan decoction significantly increased the protein levels of ABCA1 and SR-BI in THP-1 cell-derived macrophages （P<0.05 or P<0.01）. CONCLUSION Wendan decoction significantly inhibits ox-LDL-induced formation of foam cells by reducing cholesterol deposition and promoting cholesterol efflux, and its mechanism may be related to the down-regulation of CD36 and SR-A and the up-regulation of ABCA1 and SR-BI.     

朱顶红无菌苗叶片高效再生体系

以朱顶红（Hippeastrum vittatum）叶片为外植体进行离体培养，具有取材方便、试材充足、成本低等优势，但叶片诱导再生率极低，是朱顶红离体培养的一大难题。本试验中分别以‘花孔雀’和‘黑天鹅’朱顶红无菌苗叶片为外植体，探究了不同植物生长调节剂和不同取材部位对不定芽诱导和继代增殖的影响。结果表明：最佳外植体为 MS 培养基中培养 10 d 形成的幼嫩叶片基部（0.5 cm），在光照 16 h · d-1（光照强度 36 μmol · m-2 · s-1）下，不定芽诱导的最适培养基为 MS + 2 mg · L-1 6-BA + 1 mg · L-1 NAA + 2 mg · L-1 TDZ，两个品种的不定芽均以间接途径发生，其中‘花孔雀’在培养 40 d 后形成愈伤组织，55 d形成不定芽，诱导率可达 69.44%；‘黑天鹅’在培养 45 d 后形成愈伤组织，65 d 形成不定芽，诱导率达到 66.67%；最适体细胞胚诱导培养基为 MS + 2 mg · L-1 6-BA + 1 mg · L-1 PIC，‘花孔雀’和‘黑天鹅’的诱导率分别达到 66.67%和 63.89%；最佳不定芽增殖培养基为 MS + 2 mg · L-1 6-BA + 1 mg · L-1 NAA + 1 mg · L-1 TDZ，‘花孔雀’和‘黑天鹅’的增殖系数分别达到 4.67 和 3.46；在不添加植物生长调节剂的 MS培养基中进行生根培养，30 d 后两个品种的生根率均达到 100%；将生根培养 30 d 的小植株转移至室温条件下放置 3 d，摘去封口膜再驯化 3 d 后，移栽至经高温消毒的草炭︰蛭石（体积比）为 1︰1 的基质中，成活率达到 100%