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Objective@#To investigate the expression of myocyte enhancer factor 2B (MEF2B) in mantle cell lymphomas (MCL), and to analyze the correlation between the expression of MEF2B and pathological subtypes, structural subtypes, SOX11 expression and its clinical significance.@*Methods@#Paraffin-embedded tissues were stained with HE, immunohistochemistry (EnVision method) and fluorescence in situ hybridization (FISH) , in addition, the clinical and pathological data of 60 cases of MCL were collected at Sun Yat-sen University Foshan Hospital and Sun Yat-sen University Cancer Center from January,2002 to May, 2019 for analysis.@*Results@#Of the 60 MCLs, males is predominant (M∶F=3∶1). Histologically, the typical MCL is the majority (classical MCL: variant type MCL=48 cases:12 cases) . Fifty cases were classified into non-complete FDC meshwork type MCL, and the remaining 10 cases were classified into the complete-FDC meshwork type MCL group. Patients with classical MCL were more than 60 years old. The coexistent lesion sites both node and extranode in pathological subtype or structural subtype was the most common lesion sites. SOX11(+) MCL was common in classical MCL (P=0.040) and tended to be complete-FDC meshwork type MCL (P=0.086). The expression rate of MEF2B in MCL was 60.0%(36/60). This rate of MEF2B in classical type, complete-FDC meshwork type and SOX11(+) MCL was significantly higher than that variant type, no complete-FDC meshwork type, SOX11(-)MCL (P<0.05), respectively. There was no difference in clinical characteristics of MCL between MEF2B positive and negative groups. Compared with SOX11(-)MCL, the percentage of MEF2B expressed in tumor cells of SOX11(+)MCL was significantly higher (P=0.027). The expression of MEF2B was not related to the proliferation of tumor cells (P=0.341). There was no significant difference in the survival rate between different expression groups of MEF2B and SOX11 (P=0.304 and P=0.819, respectively). Only the mortality of variant type (blastoid/pleomorphic) MCL within 2 years was significantly higher than that of classical type MCL (P<0.05).@*Conclusions@#The expression of MEF2B in MCL is related to the pathological subtypes, structural subtypes and the expression of SOX11, but not to the proliferation and prognosis. The high mortality rate within 2 years is only found in variant MCL. However, the role of MEF2B in MCL needs to be further studied.
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Objective: To investigate the effect of microRNA-9-5p (miR-9-5p) targeting the myocyte enhancer factor 2C (MKF2C) on the biologicals behaviors of the alveolar rhabdomyosarcoma (ARMS) cells, and to provide the basis for the molecular diagnosis and targeted therapy of ARMS. Methods: The expression levels of miR-9-5p and MKF2C mRNA in ARMS tissue and cells were detected by qRT-PCR method' the proliferation rate of cells was detected by CCK-8 method, the apoptotic rate was detected by flow cytometry, the numbers of invasion and migration cells were detected by Transwell chamber assay, the luciferase activity in 293T cells was detected by double luciferase reporter gene, and the expression level of MEF2C protein in the cells was detected by Western blotting method. Results: The expression levels of miR-9-5p in ARMS tissue and cells were higher than those in normal skeletal muscle tissue and HSKMC cells ( P
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Objective To evaluate the role of mitochondrial ATP sensitive potassium ( mito-KATP ) channel in dexmedetomidine-induced inhibition of subarachnoid hemorrhage ( SAH )-caused programmed cell death ( PCD) in cardiomyocytes of rats. Methods On hundred and twenty clean-grade healthy male Sprague-Dawley rats, aged 9-10 weeks, weighing 350-400 g, were divided into 5 groups ( n=24 each) using a random number table method: sham operation group ( group Sham ) , SAH group, SAH plus dexmedetomidine group ( group SD) , 5-HD plus SAH and dexmedetomidine group ( group HSD) and 5-HD plus SAH group ( group HS) . The rats were subjected to SAH by intracranial vascular puncture after being anesthetized with pentobarbital sodium. Dexmedetomidine 5 μg∕kg was infused for 10 min via the jugular vein starting from the time point after intracranial vascular puncture, followed by a continuous infusion of 5μg·kg-1 ·h-1 for 1 h in SD and HSD groups. 5-HD 30 mg∕kg was intraperitoneally injected at 1 h before intracranial vascular puncture in HSD and HS groups. Blood samples were collected from the abdominal aor-ta at 24 h after intracranial vascular puncture for determination of serum cardiac troponin I ( cTnI) concen-trations. The animals were then sacrificed, and myocardial specimens were collected for determination of PCD rate ( by TUNEL) , reactive oxygen species ( ROS) activity ( by DCFH-DA assay) , and expression of cleaved caspase-3, cleaved caspase-1 and interleukin-1beta ( IL-1β) ( by Western blot) . Results Com-pared with group Sham, the serum concentrations of cTnI, PCD rate and ROS activity were significantly in-creased, and the expression of cleaved caspase-3, cleaved caspase-1 and IL-1βwas up-regulated in SAH, SD, HSD and HS groups ( P<0. 05) . Compared with group SAH, the serum concentrations of cTnI, PCD rate and ROS activity were significantly decreased, and the expression of cleaved caspase-3, cleaved caspase-1 and IL-1βwas down-regulated in group SD, and the serum concentrations of cTnI, PCD rate and ROS activity were significantly increased, and the expression of cleaved caspase-3, cleaved caspase-1 and IL-1βwas up-regulated in group HS ( P<0. 05) . Compared with group SD, the serum concentrations of cT-nI, PCD rate and ROS activity were significantly increased, and the expression of cleaved caspase-3, cleaved caspase-1 and IL-1β was up-regulated in group HSD ( P<0. 05) . Compared with group HSD, the serum concentrations of cTnI, PCD rate and ROS activity were significantly increased, and the expression of cleaved caspase-3, cleaved caspase-1 and IL-1βwas up-regulated in group HS ( P<0. 05) . Conclusion mito-KATP channel is involved in dexmedetomidine-induced inhibition of PCD in cardiomyocytes of rats with SAH.
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Background The customary puerperal practice of Natron consumption has been identified as one of the predisposing factors in the etiology of peripartum cardiomyopathy (PPCM). This study was designed to investigate the effect of Natron in postpartum Wistar albino rats. Methods A total of 30 postpartum Wistar rats were exposed to different doses (50 mg/kg, 100 mg/kg, 200 mg/kg and 300 mg/kg) of Natron for 28 days. After the treatment, we carried out biochemical analyses and histological evaluations of kidney, liver and heart. Results The study revealed that the exposure of postpartum rats to 100 mg/kg of Natron and above significantly (p < 0.05) increase the cardiac markers; myoglobin, creatine kinase-MB, troponin I and T as compared with control. The result of liver function indicated no significant difference in alanine aminotransferase, aspartate aminotransferase, gamma-glutamyltransferase, albumin and total protein of the Natron treated groups as compared with control. However, at higher doses, the levels of total protein, globulin and alkaline phosphatase activity were significantly increased in comparison to the control. There was no significant difference in the kidney function markers of the treatment groups as compared with control. Histological examinations revealed no changes in the kidney of the treated groups. Mild portal triaditis was observed in the liver of the treated rats. The heart of the rats administered ≥100 mg/kg of Natron showed myocyte hypertrophy. Conclusion The study demonstrated that the administration of Natron for 28 days caused changes in the heart of postpartum rats and thus may contribute to the pathogenesis of PPCM.
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Objective To verify antioxidation of Au NanoStars/collagen ( AuNSs/Col ) for ventricular myocytes of newborn rats(NRVMs) by in vitro studies.Methods (1)Different concentrations of AuNSs/Col composite materials were created.The optimum concentration of the material was selected by Live /dead staining and Cell Counting Kit-8 (CCK-8) and Col was used for subsequent experiments .( 2 ) NRVMs were randomly divided into Col group , AuNSs/Col group, H2O2-induced Col group, and H2O2-induced AuNSs/Col group.After 6 h treatment, apoptotic cell morphology and early cell apoptosis rate were observed with Annexin Ⅴ-FITC/propidium iodide ( PI)/4′,6-diamidino-2-phenylindole ( DAPI) and the expressions of apoptosis related proteins-B-cell lymphoma-2 ( Bcl-2 ) and Bcl-2 associated x protein ( Bax ) were detected by Western blotting .Results ( 1 ) Both Live/dead and CCK-8 experiments indicated that the AuNSs/Col composite material with 0.1 mg/ml was nontoxicity to NRVMs and could further promote their proliferation .(2) Compared with the uninduced group , the early apoptosis rate of the Col group and the AuNSs /Col group after H2O2 induction was significantly increased , while the Bcl-2/Bax ratio was decreased , indicating that the oxidative stress damage model was established.After H2O2 induction, compared with the Col group , the early apoptosis rate of the AuNSs/Col group was decreased , but the Bcl-2/Bax ratio was increased .Conclusion AuNSs/Col composite material has protective effect on the oxidative damage of cardiomyocytes cultured in vitro.
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Neuregulin-1 (NRG-1) and the ErbBs family of receptor tyrosine kinases are widely expressed in the cardiovascular system.NRG-1/ErbBs signaling plays an essential role in physiology and pathophysiology of the heart,including stabilization of cardiac myocyte structure and function,promotion of cardiac myocyte proliferation and survival,inhibition of cardiac myocyte apoptosis,reduction of myocardial interstitial fibrosis,regulation of energy utilization,and enhancement of angiogenesis and so on.Therefore,NRG-1/ErbBs signaling is involved in the development and treatment of chronic heart failure(CHF).In this review,we bring the growing literature on NRG-1/ErbBs signaling and its significance in cardiovascular development and heart failure.
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Objective:To investigate the effects of site specific (124 HNFTAGDLGP STIVGSAAFNMF145 ) antibody of Sodium calcium exchanger ( NCX) on calcium transient in single ventricular myocytes of normal adult rats .Methods: Isolated adult rat hearts were perfused using Langendorff method and single ventricular myocytes were then obtained .The ventricular myocytes were incubated with Fuar-2/AM and 2% bovine serum albumin for about 40 min and then,the fluorescence images were recorded when excitation wavelengths were 340 nm and 380 nm using ion imaging system.Fluorescence value F340/F380,length of cell shortening ,time to 90%restore( TR90 ) and calcium sensitivity ( ratio of F340/F380 and cell shortening ) were calculated.Results:The site specific antibody of NCX increased F340/F380 and decreased TR90 in single ventricular myocytes ,but had no more significant effect on calcium sensitivi-ty.Pretreatment with KB-R7943 or Nicardipine could significantly inhibit the TR 90 decrease or F340/F380 increase induced by the anti-body.Pretreating ventricular myocytes with combination of KB-R7943 and Nicardipine ,the antibody had no more significant effects on calcium transient.Conclusion:Site specific ( 124 HNFTAGDLGPSTIVGSAAFNMF145 ) antibody of NCX could increase calcium transient and accelerate the decrease of intracellular calcium during diastole ,which mainly related to its effects of activating L-type Ca2+channel and NCX.
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Objective To observe the expressions of voltage-gated sodium channel (NaCh)αsubunits in adult rat ventricular myocytes.Methods Single ventricular myocytes were isolated from adult rat heart.Expressions of various αsubunits (Nav1.1,Nav1.2,Nav1.3,Nav1.5,Nav1.6 and Nav1.7)of NaCh in the ventricular myocytes were detected by immunocytochemistry staining.Sodium current was recorded by whole-cell patch clamp method. Results The neuronal subunits Nav1.1,Nav1.6 and Nav1.7 as well as the cardiac subunit Nav1.5 of NaCh were expressed in adult rat ventricular myocytes.Nav1.1,Nav1.5 and Nav1.7 were distributed along the cell membrane of the ventricular myocytes and around the transverse tubule;Nav1.6 was labeled along the cell membrane by lengthways.All these subunits were not colocalized with Cx43 at the intercalated disc.Both transient sodium current (I Na,T )and late sodium current (I Na,L )were recorded from adult rat ventricular myocytes.Conclusion Various neuronal subunits (Nav1.1,Nav1.6 and Nav1.7)as well as cardiac subunit (Nav1.5 )of NaCh were expressed in adult rat ventricular myocytes,which is important for normal function of I Na,T and I Na,L .
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Objective To observe the expressions of voltage-gated sodium channel (NaCh)αsubunits in adult rat ventricular myocytes.Methods Single ventricular myocytes were isolated from adult rat heart.Expressions of various αsubunits (Nav1.1,Nav1.2,Nav1.3,Nav1.5,Nav1.6 and Nav1.7)of NaCh in the ventricular myocytes were detected by immunocytochemistry staining.Sodium current was recorded by whole-cell patch clamp method. Results The neuronal subunits Nav1.1,Nav1.6 and Nav1.7 as well as the cardiac subunit Nav1.5 of NaCh were expressed in adult rat ventricular myocytes.Nav1.1,Nav1.5 and Nav1.7 were distributed along the cell membrane of the ventricular myocytes and around the transverse tubule;Nav1.6 was labeled along the cell membrane by lengthways.All these subunits were not colocalized with Cx43 at the intercalated disc.Both transient sodium current (I Na,T )and late sodium current (I Na,L )were recorded from adult rat ventricular myocytes.Conclusion Various neuronal subunits (Nav1.1,Nav1.6 and Nav1.7)as well as cardiac subunit (Nav1.5 )of NaCh were expressed in adult rat ventricular myocytes,which is important for normal function of I Na,T and I Na,L .
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Objective·To observe mitochondria permeability transition pore (mPTP) opening and apoptosis of H9c2 myocardial cell stimulated by lipopolysaccharide (LPS),and to explore the anti-apoptotic effect of combined application of cyclosporine A (CsA) and ryanodine (Rya).Methods·The H9c2 cells were divided into Control group,LPS group,LPS+CsA group,LPS+Rya group,and LPS+CsA+Rya group.The mPTP opening state,Ca2+ concentration within cell and mitochondrial,mitochondrial membrane potential (AΦm),cell apoptosis,expression of Bax and Bcl-2 at mRNA and protein levels,and activity of caspase 3 were determined respectively.Results·mPTP opened after being stimulated by LPS for 24 h,which increased the fluorescence intensity for Ca2+in cytosolic and mitochondria by 298％ and 231％ respectively,induced about 1/3 cell apoptosis,improved the activity of caspase 3 approximately twice,and enhanced expression ofBax mRNA (P=0.008).The combined use of CsA and Rya effectively inhibited mPTP opening,increased the enhancement of fluorescence intensity for Ca2+in both cytosolic and mitochondria,maintained normal AΦrn,reduced LPS-induced apoptosis,inhibited the activity of caspase 3,and decreased Bax mRNA expression level induced by LPS in the myocardial cells.Conclusion·mPTP plays an important role in in LPS-induced myocardial apoptosis,whereas the combination of CsA and Rya can alleviate it effectively.
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Objective: To observe the effect of bisoprolol on cardiac function in heart failure (HF) rats and to explore the mechanism. Methods: The experimental rats were divided into 6 groups: Control group, with normal healthy rats, Sham group, the rats received intraperitoneal injection of normal saline; chronic heart failure (CHF) model was successfully established in 40 rats and divided into 4 groups: CHF group, CHF+bisoprolol (Bis) group, CHF+captopril (Cap) group and CHF+Bis and Cap group.n=10 in each group. The cardiac function was observed among different groups; plasma BNP level was measured by ELISA, myocardial miR-25-3p expression was examined by RT-PCR, protein expressions of SERCA2a and phospholamban (PLB) were detected by Western blot analysis and SERCA2a activity was determined by inorganic phosphorus method. Results: Compared with Control group, CHF group showed decreased cardiac output (CO), left ventricular fractional shortening (LVFS), left ventricular ejection fraction (LVEF), reduced expression of cardiac SERCA2a, PLB, the ratio of SERCA2a/PLB and SERCA2a activity; while increased plasma BNP and miR-25-3p expression, allP<0.01. Compared with CHF group, CHF+Bis, CHF+Cap and CHF+Bis and Cap groups had increased CO, LVFS, LVEF, elevated expression of cardiac SERCA2a, PLB, the ratio of SERCA2a/PLB and SERCA2a activity; while decreased plasma BNP and miR-25-3p expression, allP<0.05.Conclusion: Bisoprolol could improve cardiac function in HF rats, which might be related to down regulating myocardial miR-25-3p expression, up regulating myocardial protein expressions of SERCA2a, PLB and enhancing SERCA2a activity.
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Objective: To explore the protective roll of ifbroblast growth factor 21 (FGF21) in endoplasmic reticulum stress (ERS) induced rat's H9c2 cardiomyocyte apoptosis with its mechanism. Methods: pcDNA4 was used as gene vector, pcDNA4-FGF21 plasmid was constructed and transfected into rat's H9c2 myocardiocytes for 48 h. ERS model was established by 10 μM tunicamycin (TM) induction for 24 h. The experiment was conducted in 4 groups:①Control group,②TM group, the cells were treated by TM,③pcDNA4-FGF21+TM group,④pcDNA4+TM group. The expressions of FGF21, protein kinase R-like ER kinase (PERK) and c-Jun N-terminal kinases (JNK) mediated apoptosis pathway related protein were measured by Western blot analysis; cell survival rate was examined by CCK-8 method and apoptosis rate was detected by TUNEL technique. Results: pcDNA4-FGF21 vector was successfully constructed and overexpressed in H9c2 myocardiocytes. Compared with Control group, TM group and pcDNA4+TM group had up-regulated endogenous FGF21 expression, increased PERK and JNK mediated apoptosis pathway related protein expression; reduced cell survival rate and elevated apoptosis rate. Compared with TM group and pcDNA4+TM group, pcDNA4-FGF21+TM group had down-regulated PERK and JNK mediated apoptosis pathway related protein expression; increased cell survival rate and decreased apoptosis rate. Conclusion: FGF21 overexpression can reduce ERS induced apoptosis rat's H9c2 myocardiocytes which might be partly related for inhibiting PERK and JNK mediated signal transduction of apoptosis pathway.
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OBJECTIVE: To observe whether low concentration (1×10-8 mol·L-1) of ouabain (OUA) can increase the contractility in rat cardiocytes and investigate the Na/K pump signal transduction pathways related to positive inotropic action following the low concentration of OUA. METHODS: On enzymatic isolation of rats ventricular myocytes, the Na+/K+ pump current (Ip) was by whole-cell patch-clamp, in order to observe the low concentration of OUA on Ip. The contraction of a single myocyte was assessed by a video-based motion edge-detection system. (1) To detect and compare the potentiations of 1×10-8-1×10-3 mol·L-1 OUA on the contractility in rat cardiocytes. (2) The cardiocytes were pre-treated with PP2 (1 μmol·L-1), NAC (100 μmol·L-1), PD98059(50 μmol·L-1) for 5 min, and the effects of the signals transduction inhibitors on the positive inotropic effect of 1×10-8 mol·L-1 OUA was recorded. RESULTS: The 1×10-8-1×10-3 mol·L-1 OUA increased the contractility of rat cardiocytes (P0.05). CONCLUSION: The 1×10-8-1×10-3 mol·L-1 OUA could increase the contraction amplitude of cardiocytes in rats in concentration-dependent manner. Positive inotropic effect of OUA in low concentration is related to Na/K pump signal transduction. Multiple signal pathways regulate the positive inotropic effect of 1×10-8 mol·L-1 of OUA, including the Src/ROS signal pathway.
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OBJECTIVE: To investigate the expression of miRNA-1 in denervated skeletal muscle at different periods, and to explore effects of passive movement on the expression of miRNA-1 and differentiation of myoblasts in denervation-induced skeletal muscle atrophy in rats. METHODS: Twenty-seven Sprague Dawley rats, weighing (200±10) g, were randomly divided into sham-operated group (group A, n=3), denervated group (group B, n=12), and passive movement group (group C, n=12). After the right sciatic nerve was exposed and dissociated, the sciatic nerve of 1 cm in length was removed in groups B and C; resection was not performed in group A. At 1 day after operation, passive flexion and extension movement was performed on the right hind limb in group C. At 6 hours in group A and at 3, 7, 14, and 28 days in groups B and C, 3 rats were sacrificed to measure the wet weight ratio of gastrocnemius muscle, to observe the diameter of the gastrocnemius muscle cell and evaluate the muscle atrophy by HE staining; RT-PCR was used to detect the mRNA expression of miRNA-1 and myocyte differentiation factor (MyoD), and immunohistochemistry to determine the protein expression of MyoD. RESULTS: Atrophy in various degrees was observed in denervated gastrocnemius muscle of groups B and C. The muscle fiber arranged in disorder and the diameter of the muscle cells decreased gradually with the time, without normal structure and morphology. The wet weight ratio and the cell diameter of the gastrocnemius in groups B and C were significantly less than those in group A (P0.05), and had positive correlation at 14 and 28 days (P<0.05); positive correlation was found between the relative expression of MyoD and miRNA-1 mRNA (P<0.05). CONCLUSIONS: Passive movement can prevent amyotrophy by increasing the expression of miRNA-1 and promoting the differentiation of myoblasts.
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Aim To observe the cytochrome 450 effect of ginsenoside Re on H9c2 cells, in order to clarify the molecular mechanism of ginsenoside Re. Methods H 9 c 2 cells were separately treated with ginsenoside Re for 1, 5, 10, 50, 100 μmol·L-1 or 6, 24, 36, 48, 60 h. CYP2C11, 2J3, 4A1, 4A3, 4F4 and ANP mR-NA expressions were analyzed by Real time PCR, and CYP4 A1 , 2 J3 protein expressions were detected by Western blot. Results Compared with control group, ginsenoside Re could effectively upregulate CYP2 C11 , CYP2 J3 , ANP mRNA expression to 1. 6 , 1. 8 , 3. 2 fold, and downregulate CYP4A1, CYP4A3, CYP4F4 mRNA expression to 0. 4, 0. 15, 0. 3 fold. Ginsen-oside Re could decrease CYP4 A1 protein expression in a concentration-dependent manner, while ginsenoside Re could increase CYP2 J3 protein expression in a con-centration-dependent manner. Conclusion Ginsen-oside could regulate CYP450 enzyme and change ANP gene expression, which might be the molecular mecha-nism of ginsenoside Re.
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Swelling-activated chloride currents (ICl.swell) are thought to play a role in several physiologic and pathophysiologic processes and thus represent a target for therapeutic approaches. However, the mechanism of ICl.swell regulation remains unclear. In this study, we used the whole-cell patch-clamp technique to examine the role of protein kinase C (PKC) in the regulation of ICl.swell in human atrial myocytes. Atrial myocytes were isolated from the right atrial appendages of patients undergoing coronary artery bypass and enzymatically dissociated. ICl.swell was evoked in hypotonic solution and recorded using the whole-cell patch-clamp technique. The PKC agonist phorbol dibutyrate (PDBu) enhanced ICl.swell in a concentration-dependent manner, which was reversed in isotonic solution and by a chloride current inhibitor, 9-anthracenecarboxylicacid. Furthermore, the PKC inhibitor bis-indolylmaleimide attenuated the effect and 4α-PDBu, an inactive PDBu analog, had no effect on ICl.swell. These results, obtained using the whole-cell patch-clamp technique, demonstrate the ability of PKC to activate ICl,swell in human atrial myocytes. This observation was consistent with a previous study using a single-channel patch-clamp technique, but differed from some findings in other species.
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Humanos , Antracenos , Farmacologia , Canais de Cloreto , Metabolismo , Cloretos , Metabolismo , Meios de Cultura , Metabolismo , Farmacologia , Relação Dose-Resposta a Droga , Potenciais Evocados , Fisiologia , Átrios do Coração , Biologia Celular , Metabolismo , Soluções Hipotônicas , Metabolismo , Farmacologia , Indóis , Farmacologia , Transporte de Íons , Maleimidas , Farmacologia , Miócitos Cardíacos , Biologia Celular , Metabolismo , Técnicas de Patch-Clamp , Dibutirato de 12,13-Forbol , Farmacologia , Cultura Primária de Células , Proteína Quinase C , MetabolismoRESUMO
Objective:To explore whether ginsenosides-Rb1 (Gs-Rb1)can relieve cardiomyocyte hypertrophy induced by endothelin-1 (ET-1)via protein kinase C (PKC)system.Methods:Cardiomyocytes of neonatal rat were random-ly divided into blank control group,Gs-Rb1 group,ET-1 group,Gs-Rb1+ET-1 group,ET-1+CHE (chelerythrine, PKC blocker)group and Gs-Rb1 +ET-1 +CHE group.After 96h intervention,cardiomyocyte surface area,total protein content,PKC activity,c-fos and p-c-jun expressions were measured.Results: (1)Cardiomyocyte surface area and total protein content in Gs-Rb1+ET-1 group were significantly lower than those of ET-1 group (P <0.05~<0.001),but not significant different with those of Gs-Rb1+ET-1+CHE group,P =0.569;(2)PKC activity in Gs-Rb1+ET-1 group was significantly lower than that of ET-1 group [(9.3±0.6)pmol·min-1 ·mg-1 vs.(14.1± 0.9)pmol·min-1 ·mg-1 ],but significantly higher than that of Gs-Rb1+ET-1+CHE group [(2.7±0.2)pmol· min-1 ·mg-1 ],P <0.001 all;(3)Expressions of c-fos and p-c-jun gene and protein in ET-1 group were significant-ly higher than those of blank control group (P <0.001 all);compared with ET-1 group,there were significant re-ductions in expressions of c-fos [mRNA/protein:(0.53±0.05/0.39±0.02)vs.(0.43±0.03/0.31±0.03)]and p-c-jun [mRNA/protein:(0.64±0.04/0.44±0.02)vs.(0.33±0.05/0.37±0.03)]in Gs-Rb1+ET-1 group and ex-pressions of c-fos [mRNA/protein:0.41 ± 0.05/0.31 ± 0.02]and p-c-jun [mRNA/protein:0.31 ± 0.05/0.36 ±0.03]in ET-1+CHE group (P <0.05 or <0.001),expressions of c-fos and p-c-jun gene and protein in Gs-Rb1+ET-1+CHE group were significantly lower than those of Gs-Rb1+ET-1 group and ET-1+CHE group (P <0.05 or<0.001).Conclusion:Gs-Rb1 can significantly inhibit cardiomyocyte hypertrophy induced by ET-1 and PKC system is one of pathways mediating this biological effect.
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BACKGROUND/AIMS: Smooth muscle cells (SMCs) characteristically express serum response factor (SRF), which regulates their development. The role of SRF in SMC plasticity in the pathophysiological conditions of gastrointestinal (GI) tract is less characterized. METHODS: We generated SMC-specific Srf knockout mice and characterized the prenatally lethal phenotype using ultrasound biomicroscopy and histological analysis. We used small bowel partial obstruction surgeries and primary cell culture using cell-specific enhanced green fluorescent protein (EGFP) mouse lines to study phenotypic and molecular changes of SMCs by immunofluorescence, Western blotting, and quantitative polymerase chain reaction. Finally we examined SRF change in human rectal prolapse tissue by immunofluorescence. RESULTS: Congenital SMC-specific Srf knockout mice died before birth and displayed severe GI and cardiac defects. Partial obstruction resulted in an overall increase in SRF protein expression. However, individual SMCs appeared to gradually lose SRF in the hypertrophic muscle. Cells expressing low levels of SRF also expressed low levels of platelet-derived growth factor receptor alpha (PDGFRalphalow) and Ki67. SMCs grown in culture recaptured the phenotypic switch from differentiated SMCs to proliferative PDGFRalphalow cells. The immediate and dramatic reduction of Srf and Myh11 mRNA expression confirmed the phenotypic change. Human rectal prolapse tissue also demonstrated significant loss of SRF expression. CONCLUSIONS: SRF expression in SMCs is essential for prenatal development of the GI tract and heart. Following partial obstruction, SMCs down-regulate SRF to transition into proliferative PDGFRalphalow cells that may represent a phenotype responsible for their plasticity. These findings demonstrate that SRF also plays a critical role in the remodeling process following GI injury.
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Animais , Humanos , Camundongos , Western Blotting , Imunofluorescência , Trato Gastrointestinal , Coração , Camundongos Knockout , Microscopia Acústica , Células Musculares , Músculo Liso , Miócitos de Músculo Liso , Parto , Fenótipo , Plásticos , Reação em Cadeia da Polimerase , Cultura Primária de Células , Receptores do Fator de Crescimento Derivado de Plaquetas , Prolapso Retal , RNA Mensageiro , Fator de Resposta SéricaRESUMO
Objective: To observe the regulatory effects of RhoA/ROCK pathway on the apoptosis of cardiac myocyte induced by anoxia and its mechanism. Methods: The model of cardiac myocyte anoxia was established. The beat pulsations and apoptosis rates after 1 h, 3 h, 6 h, 9 h and 12 h of anoxia were recorded and the expressions of RhoA, ROCK1/2, p-PI3K, p-AKT and caspae-3 were detected, too. The apoptosis and the expressions of related proteins were detected after RNAi of RhoA and the inhibition of ROCK by Y-27632. Results: The beat pulsations after 1 h, 3 h, 6 h, 9 h and 12 h decreased gradually but the apoptosis rates increased gradually, and the expressions of RhoA, ROCK1/2, p-PI3K, p-AKT and caspase-3 were increasing along with the increasing duration of anoxia. The apoptotic rates after 1 h, 3 h, 6 h, 9 h and 12 h of anoxia were (4.36[U+4F9D]0.98)%, (8.36[U+4F9D]2.12)%, (15.32[U+4F9D]3.62)%, (18.68[U+4F9D]4.83)% and (24.56[U+4F9D]6.22)%, respectively and decreased more significantly than control group in different time points of anoxia (. P<0.05), and the expressions of RhoA, ROCK1/2, p-PI3K, p-AKT and caspase-3 decreased significantly (. P<0.05). The apoptosis rate and the expressions of RhoA, ROCK1/2, p-PI3K, p-AKT and caspase-3 decreased significantly (. P<0.05) after the inhibition of ROCK by Y-27632 (. P<0.05). Conclusions: RhoA/ROCK pathway plays a critical role in the regulation of the apoptosis of cardiac myocyte induced by anoxia, which may be accompanied by regulating the activity of PI3K/AKT/Caspase-3 pathway.
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OBJECTIVE@#To observe the regulatory effects of RhoA/ROCK pathway on the apoptosis of cardiac myocyte induced by anoxia and its mechanism.@*METHODS@#The model of cardiac myocyte anoxia was established. The beat pulsations and apoptosis rates after 1 h, 3 h, 6 h, 9 h and 12 h of anoxia were recorded and the expressions of RhoA, ROCK1/2, p-PI3K, p-AKT and caspae-3 were detected, too. The apoptosis and the expressions of related proteins were detected after RNAi of RhoA and the inhibition of ROCK by Y-27632.@*RESULTS@#The beat pulsations after 1 h, 3 h, 6 h, 9 h and 12 h decreased gradually but the apoptosis rates increased gradually, and the expressions of RhoA, ROCK1/2, p-PI3K, p-AKT and caspase-3 were increasing along with the increasing duration of anoxia. The apoptotic rates after 1 h, 3 h, 6 h, 9 h and 12 h of anoxia were (4.360.98)%, (8.362.12)%, (15.323.62)%, (18.684.83)% and (24.566.22)%, respectively and decreased more significantly than control group in different time points of anoxia (P<0.05), and the expressions of RhoA, ROCK1/2, p-PI3K, p-AKT and caspase-3 decreased significantly (P<0.05). The apoptosis rate and the expressions of RhoA, ROCK1/2, p-PI3K, p-AKT and caspase-3 decreased significantly (P<0.05) after the inhibition of ROCK by Y-27632 (P<0.05).@*CONCLUSIONS@#RhoA/ROCK pathway plays a critical role in the regulation of the apoptosis of cardiac myocyte induced by anoxia, which may be accompanied by regulating the activity of PI3K/AKT/Caspase-3 pathway.