Lysine demethylase 5B transcriptionally regulates TREM1 in human cardiac fibroblasts

Background:A differential gene,triggering receptor expressed on myeloid cells 1(TREM1),was identified in blood sequencing datasets from myocardial infarction patients and healthy controls.Myocardialfibrosis following myocardial infarction significantly contributes to cardiac dysfunction.Objectives:This study aimed to unveil the intrinsic regulatory mechanism of TREM1 in myocardialfibrosis.Methods:Mimicking pathology by angiotensin II(Ang II)treatment of human cardiacfibroblasts(HCFs),the impacts of TREM1 knockdown on its proliferation,migration,and secretion of the pro-fibrotic matrix were identified.Using the Human Transcription Factor Database(HumanTFDB)website,lysine-specific demethylase 5B(KDM5B)was found to bind to the TREM1 promoter,which was further validated through luciferase reporter and chromatin immunoprecipitation(ChIP).By promoting KDM5B overexpression,its effect on the regulation of TREM1 was examined.Results:TREM1 knockdown suppressed the proliferation,migration,and secretion of the pro-fibrotic matrix in HCFs upon Ang II treatment.KDM5B bound to the TREM1 promoter and upregulated its transcriptional expression.Furthermore,KDM5B overexpression reversed the regulation of the above cellular phenotypes by TREM1 knockdown.Conclusion:This study sheds light on the positive regulation of TREM1 by KDM5B,demonstrating their role in promoting myocardialfibrosis.Thisfinding provides a theoretical foundation for understanding disease pathology and potentially advancing the development of new targeted therapies.

Tenascin C upregulates interleukin-6 expression in human cardiac myofibroblasts via toll-like receptor 4

AIM:To investigate the effect of Tenascin C(TNC)on the expression of pro-inflammatory cytokines and matrixmetalloproteinases in human cardiac myofibroblasts(CMF).METHODS:CMF were isolated and cultured from patients undergoing coronary artery bypass grafting.Cultured cells were treated with either TNC(0.1μmol/L,24 h)or a recombinant protein corresponding to different domains of the TNC protein;fibrinogen-like globe(FBG)and fibronectin typeⅢ-like repeats(TNⅢ5-7)(both 1μmol/L,24 h).The expression of the proinflammatory cytokines;interleukin(IL)-6,IL-1β,TNFαand the matrix metalloproteinases;MMPs(MMP1,2,3,9,10,MT1-MMP)was assessed using real time RT-PCR and western blot analysis.RESULTS:TNC increased both IL-6 and MMP3(P<0.01)mR NA levels in cultured human CMF but had no significant effect on the other markers studied.The increase in IL-6 mR NA expression was mirrored by an increase in protein secretion as assessed by enzymelinked immunosorbant assay(P<0.01).Treating CMF with the recombinant protein FBG increased IL-6mR NA and protein(P<0.01)whereas the recombinant protein TNⅢ5-7 had no effect.Neither FBG nor TNⅢ5-7 had any significant effect on MMP3 expression.The expression of toll-like receptor 4(TLR4)in human CMF was confirmed by real time RT-PCR,western blot and immunohistochemistry.Pre-incubation of cells with TLR4neutralising antisera attenuated the effect of both TNC and FBG on IL-6 mR NA and protein expression.CONCLUSION:TNC up-regulates IL-6 expression in human CMF,an effect mediated through the FBG domain of TNC and via the TLR4 receptor.

Bcl6 Suppresses Cardiac Fibroblast Activation and Function via Directly Binding to Smad4

Bcl6,a critical pro-oncogene of human B-cell lymphomas,can promote tumor progress.Previous studies have found that Bcl6 participates in hypoxia injury in cardiomyocytes.However,the effect of Bcl6 on cardiac fibroblasts is still unclear.The aim of this study was to elucidate the functional role of Bcl6 in cardiac fibroblast activation and function.The neonatal rat cardiac fibroblasts were isolated and cultured.First,transforming growth factor β1 (TGFβ1) was used to stimulate fibroblast activation.A decreased expression level of Bcl6 was observed in fibroblasts after stimulation with TGFβ1.Then,cells were transfected with adenovirus Bcl6 to overexpress Bcl6.The results showed that Bcl6 overexpression induced decreased proliferation and reduced activation of fibroblasts which were stimulated with TGFβ1.It was found that activated smad2 and smad3 were not changed by overexpressing Bcl6,but smad4 was decreased.Furthermore,co-immunoprecipitation results showed that Bcl6 directly bound to smad4,and induced down-regulation of smad4.At last,smad4 activator could counteract the anti-fibroblast effects of Bcl6.In conclusion,Bcl6 may negatively regulate cardiac fibroblast activation and function by directly binding to smad4.

Calcitriol Suppressed Isoproterenol-induced Proliferation of Cardiac Fibroblasts via Integrinβ3/FAK/Akt Pathway

Objective Cardiac fibroblasts(CFs)proliferation and extracellular matrix deposition are important features of cardiac fibrosis.Various studies have indicated that vitamin D displays an anti-fibrotic property in chronic heart diseases.This study explored the role of vitamin D in the growth of CFs via an integrin signaling pathway.Methods MTT and 5-ethynyl-2′-deoxyuridine assays were performed to determine cell viability.Western blotting was performed to detect the expression of proliferating cell nuclear antigen(PCNA)and integrin signaling pathway.The fibronectin was observed by ELISA.Immunohistochemical staining was employed to evaluate the expression of integrinβ3.Results The PCNA expression in the CFs was enhanced after isoproterenol(ISO)stimulation accompanied by an elevated expression of integrin beta-3(β3).The blockade of the integrinβ3 with a specific integrinβ3 antibody reduced the PCNA expression induced by the ISO.Decreasing the integrinβ3 by siRNA reduced the ISO-triggered phosphorylation of FAK and Akt.Both the FAK inhibitor and Akt inhibitor suppressed the PCNA expression induced by the ISO in the CFs.Calcitriol(CAL),an active form of vitamin D,attenuated the ISO-induced CFs proliferation by downregulating the integrinβ3 expression,and phosphorylation of FAK and Akt.Moreover,CAL reduced the increased levels of fibronectin and hydroxyproline in the CFs culture medium triggered by the ISO.The administration of calcitriol decreased the integrinβ3 expression in the ISO-induced myocardial injury model.Conclusion These findings revealed a novel role for CAL in suppressing the CFs growth by the downregulation of the integrinβ3/FAK/Akt pathway.

Effects of glucose and aldosterone on the proliferation of cardiac fibroblasts

Objective To investigate the effects of glucose and aldosterone on the proliferation of rat cardiac fibroblasts. Methods The neonatal SD rat cardiac fibroblasts （Cfs） were separated by the differential attachment technique. Cfs were incubated in different D- glucose concentrations for 24 hours, with or without aldosterone. DNA synthesis and metabolic activity of the Cfs were measured simultaneously with Brdu incorporation and WST-1 ELISA, respectively. Results Glucose at high concentrations （15 and 25 retool/L） significantly increased the proliferation of Cfs, compared with glucose at low concentration （5.6 retool/L, P〈0.01 ）, while no difference was shown on Cfs proliferation between the two high glucose concentration groups. Addition of aldosterone （10-Tmmol/L） to low- glucose media resulted in significant proliferation compared with those without aldosterone （WST- 1, P〈0.01; Brdu, P-4）.019）. However, when incubated in high glucose media, the stimulation effect of aldosterone for Cfs proliferation disappeared （P〉0.05）. Further analysis suggested that aldosterone have significant interaction on Cfs DNA synthesis （P=0.012）. Conclusions Both glucose and aldosterone could stimulate the proliferation of cultured Cfs. In high glucose concentration, the stimulatory effect for Cfs proliferation may be masked （J Geriatr Cardio12010; 7：36-39）.

Effects of Paeonol on Expression of Type Ⅰ and Type Ⅲ Collagen of High Glucose Induced Proliferation of Cardiac Fibroblasts

[Objectives]To explore the effects of paeonol on the inhibition of myocardial fibrosis in high glucose induced cardiac fibroblasts(CFs).[Methods]Differential adherence method was used to culture the primary CFs of neonatal rats(passage culture);CCK-8 method was used to detect the cell proliferation;MTT assay was used to screen the safe concentration of paeonol;the 2 nd to 3 rd generation CFs were randomly divided into normal group(5.5 mmol/L,expressed in C),high glucose group(30 mmol/L,expressed in HG),paeonol low dose group(Pae-L,17.5 mg/L),and medium dose paeonol group(Pae-M,35 mg/L),paeonol high dose group(Pae-H,70 mg/L);Western Blot method was used to detect the expression of Col-I and Col-III protein.[Results]The extraction of CFs from primary neonatal rats was successful;high glucose(30 mmol/L)induction had a significant proliferation effect on CFs;compared with the normal group,the expressions of COI-I and Col-III protein were increased in the high glucose group(P<0.05);compared with the high glucose group,the expression of COI-I protein was decreased in each treatment group(P<0.05,P<0.01),and the decrease was most significant in the high dose group(P<0.01);the expression of COI-III in the high dose group was decreased and it was statistically significant(P<0.05).[Conclusions]Paeonol significantly inhibited the proliferation of high glucose induced CFs in neonatal rats.This experiment is intended to provide a new experimental basis for the prevention and treatment of diabetic cardiomyopathy(DCM).

Effect of aldosterone on the proliferation of rat cardiac fibroblasts

Objective:A cell model of cardiac fibroblasts proliferation induced by aldosterone was established to observe the effect of aldosterone on the proliferation of rat cardiac fibroblasts.Methods:Primary cardiac fibroblasts were cultured by trypsin digestion method and differential adhesion method,primary cardiac fibroblasts were sub-cultured by conventional digestion method,and the immunocytochemical assay was used to identify cardiac fibroblasts.The second-generation cardiac fibroblasts were randomly divided into five groups:standard control group,10-9 mol/L aldosterone(ALD1)group,10-8 mol/L aldosterone(ALD2)group,10-7 mol/L aldosterone(ALD3)group,and 10-6 mol/L aldosterone(ALD4)group.The viability of fibroblast cells in each group was detected by the 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method.Results:Vimentin staining assay showed that the cultured cells staining positive,and the purity of cultured mouse cardiac fibroblasts was 95%.The results of methyl thiazolyl tetrazolium showed that compared with the control group,the low concentration of aldosterone(10-9 mol/L)had no significant effect on the proliferation of normal cardiac fibroblasts.With the increase in the intensity of(10-8–10-6)mol/L,aldosterone could significantly promote the proliferation of cardiac fibroblasts.Moreover,there was no significant difference in absorbance value between the aldosterone group(10-6 mol/L)and the aldosterone group(10-7 mol/L)(P>0.05).The highest concentration of aldosterone group 10-7 mol/L promoted the proliferation of cardiac the optimum concentration was 10-7 mol/L.Conclusion:Aldosterone can promote the spread of cardiac fibroblasts in a specific concentration range.

芍药苷对血管紧张素Ⅱ诱导心肌成纤维细胞纤维化的保护作用

背景:研究表明芍药苷对肝、肾等器官纤维化具有改善作用,尤其是在肝纤维化中表现出突出优势,但芍药苷对于血管紧张素Ⅱ诱导的心肌纤维化的保护作用尚不明确。目的:探讨芍药苷对血管紧张素Ⅱ诱导的心肌成纤维细胞的保护作用及分子机制。方法:在分离培养的SD大鼠乳鼠心肌成纤维细胞中加入血管紧张素Ⅱ(1μmol/L)干预48 h作为模型组;芍药苷低、高剂量组给予不同剂量的芍药苷(50,100μmol/L)预处理2 h,再用血管紧张素Ⅱ处理48 h;SIRT1抑制剂组先用10μmol/L SIRT1抑制剂EX527处理2 h,再用100μmol/L芍药苷处理2 h,最后用血管紧张素Ⅱ处理48 h。采用CCK-8法检测细胞活力,Transwell检测细胞迁移能力,用DHA荧光探针检测细胞内活性氧水平,用试剂盒检测氧化应激标志物水平,Western blot检测纤维化相关基因的蛋白表达,qRT-PCR检测细胞外基质和纤维化相关基因的mRNA表达。结果与结论:①与对照组相比,血管紧张素Ⅱ干预后心肌成纤维细胞的增殖、迁移能力明显提高,细胞内活性氧和丙二醛水平升高,超氧化物歧化酶和过氧化氢酶活性降低,α-平滑肌肌动蛋白、Ⅰ型胶原蛋白、Ⅲ型胶原蛋白、纤维连接蛋白、结缔组织生长因子、基质金属蛋白酶9的mRNA表达增加;与模型组相比,芍药苷剂量依赖性抑制上述效应改变(P<0.01);②与模型组相比,芍药苷剂量依赖性上调SIRT1的蛋白表达(P<0.001);③与芍药苷高剂量组相比,SIRT1抑制剂组细胞迁移数量、α-平滑肌肌动蛋白、Ⅰ型胶原蛋白、Ⅲ型胶原蛋白表达水平显著增加(P<0.01)。结果表明,芍药苷可能通过上调SIRT1的表达,有效减轻了血管紧张素Ⅱ诱导的心肌成纤维细胞纤维化改变,剂量依赖性地抑制了心肌成纤维细胞氧化应激和细胞外基质沉积,对于心肌成纤维细胞纤维化具有保护作用。

Significant roles of anti-aging protein klotho and fibroblast growth factor23 in cardiovascular disease

The klotho gene has been identified as an aging suppressor that encodes a protein involved in cardiovascular disease （CVD）. The inac- tivation of the klotho gene causes serious systemic disorders resembling human aging, such as atherosderosis, diffuse vascular calcification and shortened life span. Klotho has been demonstrated to ameliorate vascular endothelial dysfunction and delay vascular calcification. Fur- thermore, klotho gene polymorphisms in the human are associated with various cardiovascular events. Recent experiments show that klotho may reduce transient receptor potential canonical6 （TRPC6） channels, resulting in protecting the heart from hypertrophy and systolic dys- function. Fibroblast growth factor23 （FGF23） is a bone-derived hormone that plays an important role in the regulation of phosphate and vi- tamin D metabolism. FGF23 accelerates urinary phosphate excretion and suppresses 1,25-dihydroxy vitaminD3 （1,25（OH）2D3）synthesis in the presence ofFGF receptorl （FGFR1） and its co-receptor ldotho, principally in the kidney. The hormonal affects of circulating klotho pro- tein and FGF23 on vascular and heart have contributed to an understanding of their roles in the pathophysiology of arterial stiffness and left ventricular hypertrophy. Klotho and FGF23 appear to play a critical role in the pathogenesis of vascular disease, and may represent a novel potential therapeutic strategy for clinical intervention.

Decellularized heart extracellular matrix alleviates activation of hiPSC-derived cardiac fibroblasts

Human induced pluripotent stem cell derived cardiac fibroblasts(hiPSC-CFs)play a critical role in modeling human cardiovascular diseases in vitro.However,current culture substrates used for hiPSC-CF differentiation and expansion,such as Matrigel and tissue culture plastic(TCPs),are tissue mismatched and may provide pathogenic cues.Here,we report that hiPSC-CFs differentiated on Matrigel and expanded on tissue culture plastic(M-TCP-iCFs)exhibit transcriptomic hallmarks of activated fibroblasts limiting their translational potential.To alleviate pathogenic activation of hiPSC-CFs,we utilized decellularized extracellular matrix derived from porcine heart extracellular matrix(HEM)to provide a biomimetic substrate for improving hiPSC-CF phenotypes.We show that hiPSC-CFs differentiated and expanded on HEM(HEM-iCFs)exhibited reduced expression of hallmark activated fibroblast markers versus M-TCP-iCFs while retaining their cardiac fibroblast phenotype.HEM-iCFs also maintained a reduction in expression of hallmark genes associated with pathogenic fibroblasts when seeded onto TCPs.Further,HEM-iCFs more homogenously integrated into an hiPSC-derived cardiac organoid model,resulting in improved cardiomyocyte sarcomere development.In conclusion,HEM provides an improved substrate for the differentiation and propagation of hiPSC-CFs for disease modeling.

Regulations of Thyroid Hormone on Cardiac Protein Kinase C Signal Pathway in vitro

The experiments were conducted to assess the influences of thyroid hormone on cardiac protein kinase C(PKC) signal pathway with cultured cardiac myocytes and fibroblasts as the models. Cells were pretreated with 1% newborn calf serum (NCS) or angiotensin II (Ang II), and then following by a triiodothyronine (T3) treatment. The PKC activity, PKCα and PKCε expressions were analyzed and compared. In 1% NCS pretreatment, T3 could inhibit PKC activity and PKCε expression in cardiac myocytes. The AngII pretreatment led to an increase of PKC activity and PKCε expression in cardiac myocytes, and an increase of PKC activity in cardiac fibroblasts. Following by T3 treatment, the increased PKC activity and PKCε expression in cardiac myocytes were markedly decreased. In conclusion, whether in 1% NCS or in Ang II pretreatment, T3 could inhibit PKC activity and PKCε expression in cardiac myocytes. Key words thyroid hormone - cardiac myocytes - cardiac fibroblasts - protein kinase C CLC number Q 572 Foundation item: Supported by the Natural Science Foundation of Hubei Province (98091)Biography: WANG Bao-hua (1974-), female, Ph. D, research direction: cardiovascular pathophysiology.

Cardiac stromal cells on stage:From dull filler to specialized actors

Cardiac stromal cells have faced through the years a significant evolution in their definitions concerning their phenotypes,markers,and functions.They are surging to key roles in physiopathology,becoming important targets to be exploited for cardiac repair.In this perspective,we briefly discuss their role in novel therapeutic strategies for enhancing cardiac repair and regeneration.

EFFECTS OF EPCs OR b-FGF INTRAMYOCARDIAL INFUSION ON CARDIAC FUNCTION AND NEOVASCULARIZATION FOR DILATED CARDIOMYOPATHY RATS

Objective To compare the different effects of endothelia progenitor cells （ EPCs ） or basic fibroblast growth factor （b-FGF） intromyocardial infusion on cardiac function and neovascularization for dilated cardiomyopathy（ DCM） rats. Methods Fifty adult female rats received inguinal subcutaneous injections of isoproterenol （ISO, 250 mg/kg） for induction of DCM. Four weeks later, the model rats were randomly divided into EPCs group, b-FGF group and control group. The 2×106 EPCs （ resolved in 100 μL PBS） , 100 μL b-FGF （ lO0 μg/mL ） and 100 μL PBS were evenly transplanted into the myocardium of EPCs group, b-FGF group and control group, respectively. Three months later, echocardiographic examination and regional myocardial blood flow （RMBF） measurement were performed. EPCs were traced by fluorescence in situ hybridization （FISH）. The protein and mRNA expression of b-FGF in each group was measured by ELISA assay and reverse transcription-polymerase chain reaction （ RT-PCR ） . Results Three months after transplantation, sry positive cells were detected only in EPCs group. The cardiac function as well as RMBF was significantly improved in EPCs group compared with b-FGF group or control group. There was higher capillary density in EPCs group. The protein and mRNA expression of b-FGF was stronger than b-FGF group and control group. Conclusion Transplantation of EPCs can improve cardiac function, induce neovascularization and increase RMBF for DCM rats. The treatment with EPCs has better effect than administration of b-FGF alone.

活血潜阳祛痰方抑制心肌成纤维细胞增殖的机制研究

目的观察活血潜阳祛痰方(HQQR)对血管紧张素Ⅱ(AngⅡ)诱导的心肌成纤维细胞(CFs)增殖的影响及可能机制。方法分离、培养SD大鼠原代CFs,并进行鉴定。应用AngⅡ诱导CFs建立体外心肌纤维化模型。将CFs分成空白细胞组、AngⅡ组、AngⅡ+HQQR(低剂量)组、AngⅡ+HQQR(高剂量)组和AngⅡ+缬沙坦组,作用48 h。应用CCK-8法检测各组细胞增殖水平,流式细胞仪检测各组细胞ROS水平,Elisa检测各组上清中羟脯氨酸水平,蛋白质免疫印迹(Western blot)检测NADPH氧化酶4(NOX4)、核因子κB p65(NF-κB p65),细胞外信号调节激酶1/2(ERK1/2)和p-ERK1/2的水平,对相关数据进行统计分析。结果HQQR可显著改善AngⅡ诱导CFs增殖。AngⅡ组上清中羟脯氨酸水平显著高于空白组(P<0.05),ROS水平和NOX4蛋白表达量亦显著升高(P<0.05)。AngⅡ刺激CFs后,细胞中NF-κB p65蛋白表达量和ERK1/2磷酸化比值高于空白细胞组(P<0.05)。HQQR治疗可以改善CFs增殖和胶原分泌,降低ROS水平,并显著减少NOX4、NF-κB p65蛋白表达量和ERK1/2磷酸化比值,差异有统计学意义(P<0.05)。结论HQQR可能通过抑制氧化应激、减轻炎症反应来抑制CFs增殖,改善心肌纤维化。

过表达sFRP3对小鼠原代心肌成纤维细胞活化增殖的影响

目的探讨Wnt信号通路调控剂分泌型卷曲相关蛋白3(sFRP3)在小鼠心肌成纤维细胞(CFs)活化增殖中的作用。方法购入1~3 d的小鼠乳鼠,行手术对心脏取材,消化后分离CFs进行培养。细胞贴壁生长后使用转化生长因子(TGF-β1)刺激构建CFs活化增殖模型;确认模型构建成功后分别向实验组和对照组细胞转染sFRP3过表达质粒和空载质粒24~48 h。通过Western blot、qRT-PCR的方法在分子层面对sFRP3、Periostin(POSTN)、Ⅰ型胶原(CollagenⅠ)和增殖细胞核抗原(PCNA)的表达进行检测;使用MTT法、CCK-8法和EdU染色法检测细胞增殖能力的改变。结果在TGF-β1刺激构建的CFs活化增殖模型中,相较于对照组,模型组sFRP3蛋白及mRNA表达下降,活化增殖相关蛋白PCNA、POSTN和CollagenⅠ表达上调。另外,在质粒转染sFRP3过表达组的CFs中,PCNA、POSTN和CollagenⅠ蛋白及mRNA表达相较于空载组下降。MTT、CCK-8与EdU实验表明,质粒转染sFRP3过表达组的CFs增殖活性较空载组明显下降。结论过表达sFRP3明显抑制CFs活化增殖,提示sFRP3可能是参与调控CFs活化增殖的关键基因。

红景天苷对血管紧张素Ⅱ诱导心肌成纤维细胞纤维化的保护作用

背景:目前已有研究表明红景天苷对多器官纤维化具有改善作用,但红景天苷对血管紧张素Ⅱ引起心肌成纤维细胞纤维化的保护作用尚不明确。目的:探究红景天苷对血管紧张素Ⅱ诱导的SD大鼠心肌成纤维细胞氧化应激及细胞外基质沉积的保护作用及其作用机制。方法:血管紧张素Ⅱ诱导心肌成纤维细胞纤维化,实验分为5组:正常对照组;模型组(培养基血管紧张素Ⅱ终浓度为1μmol/L);红景天苷低剂量和高剂量组(加入红景天苷50,100μmol/L处理2 h,再加入血管紧张素Ⅱ共同孵育48 h);SIRT1抑制剂组(加入SIRT1抑制剂EX52710μmol/L处理2 h,再加高剂量红景天苷处理2 h,再加血管紧张素Ⅱ共同孵育48 h)。使用CCK8法检测各组细胞活力,Transwell检测细胞迁移率,DCFH-DA荧光探针检测细胞内活性氧水平,试剂盒检测细胞内丙二醛含量、超氧化物歧化酶和过氧化氢酶活性;采用Western blot和qRT-PCR法检测心肌成纤维细胞纤维化相关mRNA和蛋白的表达水平。结果与结论:①经Vimentin荧光鉴定实验细胞为心肌成纤维细胞;②与正常对照组相比,模型组细胞活力、细胞迁移率、活性氧水平、丙二醛含量显著增加,超氧化物歧化酶和过氧化氢酶活性明显降低,LOXL2、α-SMA、胶原蛋白Ⅰ、胶原蛋白ⅢmRNA和蛋白表达显著升高,SIRT1蛋白表达水平明显降低(均P<0.01);与模型组相比,红景天苷低、高剂量组上述指标呈现相反的变化(均P<0.05),且红景天苷呈剂量依赖性调控;与红景天苷组相比,SIRT1抑制剂组细胞迁移率、α-SMA蛋白表达水平显著增加(均P<0.001);③结果表明,红景天苷对血管紧张素Ⅱ诱导的心肌成纤维细胞具有保护作用,能够剂量依赖性地抑制氧化应激和细胞外基质沉积。

姜黄素对TGF-β1诱导的心脏成纤维细胞表达NGF、IL-1β、TNF-α的影响及机制研究

目的观察姜黄素对转化生长因子-β1(Transforming growth factor-β1,TGF-β1)诱导的心脏成纤维细胞表达神经生长因子(Nerve growth factor,NGF)和炎症因子的影响,并探讨其可能的作用机制。方法在体外通过TGF-β1刺激心脏成纤维细胞,模拟心肌梗死(Myocardial in-farction,MI)模型。分组为Control组、TGF-β1组、美托洛尔(Myto)组,姜黄素微、低、中、高剂量(CCM-5、10、20、40)组。造模时间为48 h,药物处理时间为48 h。使用RT-qPCR检测NGF、Hes1、Hey1、NICD的mRNA表达水平,Western blot法检测NGF、Hes1、Hey1、NICD的蛋白表达水平,Elisa检测细胞上清中炎症因子IL-1β、TNF-α含量。结果与Control组比较,TGF-β1组细胞中NGF、Hes1、Hey1、NICD的mRNA及其蛋白表达水平明显升高(P<0.05),细胞上清中IL-1β、TNF-α含量明显升高(P<0.05)。与TGF-β1组比较,CCM-5组、CCM-10组、CCM-20组、CCM-40组的NGF、Hes1、Hey1、NICD的mRNA及蛋白表达水平与IL-1β、TNF-α含量均有不同程度的降低,部分组间比较差异有统计学意义(P<0.05),并且这些指标具有姜黄素浓度依赖性。结论姜黄素可以下调TGF-β1诱导的心脏成纤维细胞中NGF和IL-1β、TNF-α的表达,具有抗交感神经重构和抗炎作用,其机制可能与Notch信号通路的活化有关。

CircSLC8A1_005通过编码蛋白抑制心肌成纤维细胞纤维化表型的作用

【目的】探究环形RNA circSLC8A1_005调控心肌成纤维细胞纤维化表型的作用及可能机制。【方法】利用腺病毒介导在小鼠心肌成纤维细胞(mCFs)中过表达circSLC8A1_005,并检测mCFs中纤维化相关因I型胶原α1链(Col1a1)、Ⅲ型胶原α1链(Col3a1)和平滑肌肌动蛋白α2(Acta2)基因表达,通过EdU和划痕实验检测不同干预对mCFs的增殖和迁移能力的影响。双萤光素酶报告基因实验检测circSLC8A1_005包含的潜在核糖体进入序列(IRES)的活性。通过Western blot实验检测circSLC8A1_005翻译蛋白SLC8A1-605aa及其在细胞内分布情况。双萤光素酶报告基因实验检测SLC8A1-605aa对超氧化物歧化酶2(Sod2)的转录激活作用。通过RNA结合蛋白免疫沉淀(RIP)实验检测SLC8A1-605aa与Sod2 mRNA的结合作用。放线菌素D实验检测SLC8A1-605aa对Sod2 mRNA稳定性的影响。【结果】利用腺病毒可在mCFs中有效介导过表达circSLC8A1_005,过表达circSLC8A1_005可显著抑制mCFs中纤维化相关基因表达,抑制mCFs的增殖和迁移能力。双萤光素酶报告基因实验结果提示circ⁃SLC8A1_005包含的2个IRES具有活性。Western blot检测结果显示circSLC8A1_005可翻译预期大小为70 ku的SLC8A1-605aa蛋白,并主要分布于细胞核内。过表达SLC8A1-605aa和circSLC8A1_005可一致地抑制mCFs的纤维化表型。SLC8A1-605aa可特异上调超氧化物歧化酶2(Sod2)表达,但并不能转录激活Sod2表达;RIP实验结果显示SLC8A1-605aa与Sod2 mRNA有特异结合作用,而放线菌素D实验结果显示SLC8A1-605aa能够增强Sod2 mRNA的稳定性。【结论】CircSLC8A1_005通过翻译蛋白SLC8A1-605aa发挥抑制心肌成纤维细胞纤维化表型的作用,SLC8A1-605aa可能是潜在的用于心肌纤维化治疗的靶点。

心肌梗死后心肌纤维化小鼠心肌线粒体功能和能量代谢重塑相关性的转录组学分析

目的探究心肌梗死小鼠心肌纤维化过程中线粒体呼吸功能的变化,阐述其与糖酵解通量增加的相关性。方法选取40只C57BL/6N小鼠,随机分为实验组(心肌梗死组)和对照组(假手术组),20只/组。实验组采用结扎冠状动脉左前降支的方法构建小鼠心肌梗死模型,对照组除不对左前降支进行结扎外,其他操作均与实验组相同。选取心肌梗死后28d和假手术组小鼠各5只进行安乐死取材,取左心室组织样本进行转录组学测序,采用FPKM法计算基因表达量,寻找差异表达基因。并通过GO和KEGG数据库对差异基因进行富集分析,寻找影响疾病进程的相关通路。通过绘制热图,展示富集分析中显示的通路和相关基因的表达差异,并对体外培养的小鼠原代CFs通过促纤维化激动剂TGF-β1或溶剂对照干预,通过Seahorse实验检测其线粒体呼吸和糖酵解水平。结果通过心脏大体图和心脏超声验证心梗模型构建成功,心肌梗死组舒张期左心室内径增加(P<0.05),收缩期左心室内径增加更为显著(P<0.001),左心室射血分数明显下降,差异有统计学意义(P<0.0001)。与假手术组相比,心肌梗死组上调基因124个,下调基因106个。GO和KEGG富集分析显示差异表达基因显著富集在脂肪酸代谢、细胞器等代谢通路和线粒体中。基因表达热图显示脂肪酸β氧化和线粒体功能障碍,相反糖酵解水平增加。Seahorse实验中,与溶剂对照组(Vehicle组)相比,TGF-β1干预组心肌成纤维细胞基础和最大呼吸水平明显降低,基础和最大糖酵解水平升高,差异均有统计学意义(P<0.0001)。结论在心肌纤维化过程中,心肌成纤维细胞能量代谢重塑,线粒体功能下降,相反更倾向于通过糖酵解产生能量。