Effect of Chaiqinchengqi decoction on sarco/endoplasmic reticulum Ca^(2+)-ATPase mRNA expression of pancreatic tissues in acute pancreatitis rats

AIM: To investigate the effect of Chaiqinchengqi decoction (CQCQD) on sarco/endoplasmic reticulum Ca2+-ATPase (SERCA) mRNA expression of pancreatic tissues in acute pancreatitis (AP) rats. METHODS: Thirty Sprague-Dawley (SD) rats were randomized into control group, AP group and CQCQD group (n = 3 × 10). The rats in the CQCQD group were intragastrically administered with CQCQD (10 mL/kg every 2 h) after induction of AP by intraperitoneal injection of caerulein (50 μg/kg.h × 5) within 4 h. At 6 h after the induction of AP model, pancreatic tissues were collected for the pathological observation, mRNA extraction for determination of SERCA1 and SERCA2 mRNA expression or pancreatic acinar cell isolation for measurement of fluorescence intensity (FI) of intracellular calcium ion concentration [Ca2+]i. RESULTS: There was no expression of pancreatic SERCA1 mRNA in the control group and the AP group. The expression of pancreatic SERCA2 mRNA in the AP group was down-regulated (expression ratio = 0.536; P = 0.001) compared with the control group, while that in the CQCQD group was up-regulated (expression ratio= 2.00; P = 0.012) compared with AP group. The FI of intracellular [Ca2+] of pancreatic acinar cells in the AP group (138.2 ± 23.1) was higher than the C group (111.0 ± 18.4) and the CQCQD group (118.7 ± 15.2 ) (P < 0.05) and the pancreatic pathological score in the CQCQD group was lower than that in the AP group (5.7 ± 1.9 vs 9.2 ± 2.7, P < 0.05).CONCLUSION: CQCQD can up-regulate the expression of SERCA2 mRNA of pancreatic tissues, reduce intracellular calcium overload and relieve pancreatic tissue lesions.

心肌肌浆网Ca^(2+)-ATP酶研究进展

在正常心肌舒张期,心肌肌浆网Ca2+-ATP酶(SERCA2a)将Ca2+从胞质中摄回肌浆网中,在心肌肥厚、心力衰竭等病理生理过程中有多条信号通路对SERCA2a进行调节,使其活性和表达量下调。通过转基因及药物治疗上调SERCA2a的表达,可能会成为心力衰竭等疾病治疗的新手段。

Ryanodine receptor RyR1-mediated elevation of Ca^(2+)concentration is required for the late stage of myogenic differentiation and fusion

Background:Cytosolic Ca^(2+)plays vital roles in myogenesis and muscle development.As a major Ca^(2+)release channel of endoplasmic reticulum(ER),ryanodine receptor 1(RyR1)key mutations are main causes of severe congenital myopathies.The role of RyR1 in myogenic differentiation has attracted intense research interest but remains unclear.Results:In the present study,both RyR1-knockdown myoblasts and CRISPR/Cas9-based RyR1-knockout myoblasts were employed to explore the role of RyR1 in myogenic differentiation,myotube formation as well as the potential mechanism of RyR1-related myopathies.We observed that RyR1 expression was dramatically increased during the late stage of myogenic differentiation,accompanied by significantly elevated cytoplasmic Ca^(2+)concentration.Inhibition of RyR1 by siRNA-mediated knockdown or chemical inhibitor,dantrolene,significantly reduced cytosolic Ca^(2+)and blocked multinucleated myotube formation.The elevation of cytoplasmic Ca^(2+)concentration can effectively relieve myogenic differentiation stagnation by RyR1 inhibition,demonstrating that RyR1 modulates myogenic differentiation via regulation of Ca^(2+)release channel.However,RyR1-knockout-induced Ca^(2+)leakage led to the severe ER stress and excessive unfolded protein response,and drove myoblasts into apoptosis.Conclusions:Therefore,we concluded that Ca^(2+)release mediated by dramatic increase in RyR1 expression is required for the late stage of myogenic differentiation and fusion.This study contributes to a novel understanding of the role of RyR1 in myogenic differentiation and related congenital myopathies,and provides a potential target for regulation of muscle characteristics and meat quality.

New insight into Ca^(2+)-permeable channel in plant immunity

Calcium ions(Ca^(2+)) are crucial intracellular second messengers in eukaryotic cells. Upon pathogen perception, plants generate a transient and rapid increase in cytoplasmic Ca^(2+)levels, which is subsequently decoded by Ca^(2+)sensors and effectors to activate downstream immune responses. The elevation of cytosolic Ca^(2+)is commonly attributed to Ca^(2+)influx mediated by plasma membranelocalized Ca^(2+)–permeable channels. However, the contribution of Ca^(2+)release triggered by intracellular Ca^(2+)-permeable channels in shaping Ca^(2+)signaling associated with plant immunity remains poorly understood. This review discusses recent advances in understanding the mechanism underlying the shaping of Ca^(2+)signatures upon the activation of immune receptors, with particular emphasis on the identification of intracellular immune receptors as non-canonical Ca^(2+)-permeable channels. We also discuss the involvement of Ca^(2+)release from the endoplasmic reticulum in generating Ca^(2+)signaling during plant immunity.

Cardioprotective Effects of Qishen Granule(芪参颗粒)on Sarcoplasmic Reticulum Ca^2＋ Handling in Heart Failure Rats

Objective：To assess the effects of Qishen Granule（芪参颗粒, QSG） on sarcoplasmic reticulum（SR） Ca^2＋ handling in heart failure（HF） model of rats and to explore the underlying molecular mechanisms. Methods：HF rat models were induced by left anterior descending coronary artery ligation surgery and high-fat diet feeding. Rats were randomly divided into sham（n=10）, model（n=10）, QSG（n=12, 2.2 g/kg daily） and metoprolol groups（n=12, 10.5 mg/kg daily）. The therapeutic effects of QSG were evaluated by echocardiography and blood lipid testing. Intracellular Ca^2＋ concentration and sarco-endoplasmic reticulum ATPase 2a（SERCA2a） activity were detected by specific assay kits. Expressions of the critical regulators in SR Ca^2＋ handling were evaluated by Western blot and real-time quantitative polymerase chain reaction. Results：HF model of rats developed ventricular remodeling accompanied with calcium overload and defective Ca^2＋ releaseuptake cycling in cardiomyocytes. Treatment with QSG improved contractive function, attenuated ventricular remodeling and reduced the basal intracellular Ca^2＋ level. QSG prevented defective Ca^2＋ leak by attenuating hyperphosphorylation of ryanodine receptor 2, inhibiting expression of protein kinase A and up-regulating transcriptional expression of protein phosphatase 1. QSG also restored Ca^2＋ uptake by up-regulating expression and activity of SERCA2 a and promoting phosphorylation of phospholamban. Conclusion：QSG restored SR Ca^2＋cycling in HF rats and served as an ideal alternative drug for treating HF.

SERCA2表达对哮喘大鼠气道平滑肌细胞分泌IL-8的影响

目的探讨哮喘大鼠气道平滑肌细胞(ASMCs)中肌浆/内质网Ca^2+-ATP酶(SERCA2)的表达对IL-8分泌的影响。方法建立卵清蛋白(OVA)诱导的哮喘大鼠模型,分离原代ASMCs,分别用qRT-PCR及Western blotting、Fura PE-3/AM和ELISA法检测各组ASMCs中SERCA2表达、细胞内Ca^2+浓度([Ca^2+]i)和IL-8,利用si RNA技术下调SERCA2、毒胡萝卜素(TSG)抑制SERCA2以及吡咯烷二硫氨基甲酸(PDTC)抑制NF-κB活化,检测不同状态下IL-8的变化。结果与正常组比较,哮喘组SERCA2的表达减少,经缓激肽(BK)刺激的钙瞬变峰值明显下降,需更长时间重新摄取钙使[Ca^2+]i恢复至基线水平,IL-8基础值和经IL-17刺激后的诱导值均增加(P<0.05或0.01)。无论有无IL-17刺激,基因下调组IL-8 m RNA表达和分泌均显著增加(均P<0.01),与哮喘对照组比较差异均无统计学意义(均P>0.05)。哮喘组IκBα磷酸化和NF-κB p65核转位均较正常组增加(P<0.05或0.01),基因下调组和TSG抑制组的NF-κB p65核转位亦增加(P<0.05或0.01),而使用PDTC后,基因下调组、哮喘对照组和正常对照组在IL-17刺激诱导下的IL-8 m RNA表达和分泌均减少(P<0.05或0.01)。结论哮喘大鼠ASMCs中SERCA2表达减少,导致钙稳态的改变,可能通过增强NF-κB活化来介导IL-8分泌亢进。

Piezo1 suppression reduces demyelination after intracerebral hemorrhage

Piezo1 is a mechanically-gated calcium channel.Recent studies have shown that Piezo1,a mechanically-gated calcium channel,can attenuate both psychosineand lipopolysaccharide-induced demyelination.Because oligodendrocyte damage and demyelination occur in intracerebral hemorrhage,in this study,we investigated the role of Piezo1 in intracerebral hemorrhage.We established a mouse model of cerebral hemorrhage by injecting autologous blood into the right basal ganglia and found that Piezo1 was largely expressed soon(within 48 hours)after intracerebral hemorrhage,primarily in oligodendrocytes.Intraperitoneal injection of Dooku1 to inhibit Piezo1 resulted in marked alleviation of brain edema,myelin sheath loss,and degeneration in injured tissue,a substantial reduction in oligodendrocyte apoptosis,and a significant improvement in neurological function.In addition,we found that Dooku1-mediated Piezo1 suppression reduced intracellular endoplasmic reticulum stress and cell apoptosis through the PERK-ATF4-CHOP and inositol-requiring enzyme 1 signaling pathway.These findings suggest that Piezo1 is a potential therapeutic target for intracerebral hemorrhage,as its suppression reduces intracellular endoplasmic reticulum stress and cell apoptosis and protects the myelin sheath,thereby improving neuronal function after intracerebral hemorrhage.

WeiTsing: a new face of Ca^(2+)-permeable channels in plant immunity

Plants employ pattern-and effector-triggered immunity(PTI and ETI)to synergistically defend invading pathogens and insect herbivores.Both PTI and ETI can induce cytosolic Ca^(2+)spikes,despite in different spatiotemporal patterns,to activate downstream Ca^(2+)-dependent immune signaling cascades.While multiple families of Ca^(2+)-permeable channels at the plasma membrane have been uncovered,the counterparts responsible for Ca^(2+)release from intracellular stores remain poorly understood.In a groundbreaking paper published recently by Cell,the authors reported that WeiTsing,an Arabidopsis endoplasmic reticulum(ER)-resident protein that was specifically expressed in the pericycle upon Plasmodiophora brassicae(Pb)infection,could form resistosome-like Ca^(2+)-conducting channel and protect the stele of Brassica crops from Pb colonization.As the channel activity of WeiTsing was indispensable for its immune function,the findings highlight a previously underappreciated role of Ca^(2+)release from intracellular repertoire in promoting plant disease resistance.

异莲心碱防止高血压大鼠左室肥厚的可能机制

背景既往报告异莲心碱是从莲子心中分离的一种双苄基喹啉生物碱单体,具有抗心律失常、Ca^(2+)拮抗及阻断α受体作用,对高血压左室肥厚有不同程度的改善。高血压左室肥厚心肌肌浆网钙泵(SERCA)活力较正常心肌降低。目的探讨异莲心碱对高血压大鼠左室肥厚及SERCA活力的影响。方法将二肾一夹肾血管性高血压大鼠(RHR)模型,随机分为3组:正常对照组、肾血管性高血压大鼠对照组(未治疗RHR组)和异莲心碱治疗组。在异莲心碱治疗组持续给药10周后,分别测定各组大鼠的血压、左室质量/体质量,以及左室心肌SERCA活力。结果治疗后,异莲心碱治疗组血压(136.4±14.6)mm Hg较未治疗RHR组(189.8±4.4)mm Hg显著降低(P<0.01);异莲心碱治疗组左室质量/体质量(2.23±0.43)也较未治疗RHR组(2.93±0.52)显著降低(P<0.05);异莲心碱治疗组左室心肌SERCA活力[(0.91±0.18)μmol/(g protein·min)]较未治疗RHR组[(0.61±0.23)μmol/(g protein·min)]显著升高(P<0.05),但仍较正常对照组[(1.32±0.18)μmol/(g protein·min)]低(P<0.01)。结论异莲心碱能降低RHR的血压,减低RHR的左室质量/体质量,对高血压左室肥厚具有一定的防治作用;其机制可能与异莲心碱能升高RHR肥厚心肌肌浆网SERCA活力,改善心肌细胞内钙超载有关。

心力衰竭大鼠心肌β_3肾上腺素受体表达及其对钙离子相关调节蛋白的作用

目的研究心力衰竭(HF)大鼠心肌β3肾上腺素受体(beta3-adrenergic receptors,β3-AR)表达情况及对钙离子相关调节蛋白的作用。方法以正常大鼠作对照组,皮下注射生理盐水;实验组大鼠皮下注射异丙肾上腺素(Isoproterenol,ISO),常规饲养8w。造模成功后实验组随机分为3组,激动剂组给予尾静脉注射β3-AR激动剂BRL37344,抑制剂组给予尾静脉注射β3-AR抑制剂SR59230A,HF组给予生理盐水。用药8w后行心脏彩超、RT-PCR法检测心肌组织钙调蛋白(CaM)、钙调蛋白激酶Ⅱ(CaMKⅡ)、肌内质网Ca2+-ATP酶异构体2a(SERCA2a)的mRNA表达。结果①HF组较对照组β3-ARmRNA表达水平增高,CaM、CaMKⅡ、SERCA2amRNA表达水平减低(均P<0.05)。②与HF组相比较,激动剂组β3-ARmRNA水平表达增加,CaM、CaMKⅡ、SERCA2a表达进一步减少(均P<0.05)。③抑制剂组β3-ARmRNA表达水平较对照组减少,CaM、CaMKⅡ、SERCA2a较对照组减低,但较HF组增加(均P<0.05)。结论β3-AR激动剂减低衰竭心肌CaM、CaMKⅡ、SERCA2a的mRNA表达,导致心功恶化,β3-AR抑制剂则相反,可延缓HF进展,预示β3-AR抑制剂在药物治疗HF中的应用前景。

腹主动脉缩窄型高血压大鼠心肌肌浆网钙泵活力的测定

目的:观察腹主动脉缩窄型高血压大鼠心肌肌浆网钙泵活力。方法:20只雄性SD大鼠随机分为2组(每组10只):假手术组和腹主动脉缩窄高血压组。鼠尾容积法测定术前1周和术后2周及4周的血压变化。4周后处死大鼠,测定大鼠心脏重量、左室重量和左室重量指数;无机磷酸根法测定心肌肌浆网钙泵活力,双波长荧光分光光度计检测心肌细胞内钙离子浓度。结果:腹主动脉缩窄型高血压组收缩压和左室重量指数明显高于假手术组(P<0.01);与假手术组比较,腹主动脉缩窄型高血压组心肌细胞内钙离子浓度明显升高(P<0.01),心肌肌浆网钙泵活力显著降低(P<0.01)。结论:心肌肌浆网钙泵活力下降、心肌细胞钙离子浓度升高可能参与了缩窄升主动脉引起压力超负荷所致大鼠的心肌肥厚。

肌浆网-内质网钙离子转运ATP酶干扰慢病毒表达载体构建及稳定转染PC 12细胞株的建立

目的构建肌浆网-内质网钙离子转运ATP酶(SERCA)基因的干扰慢病毒表达载体,建立稳定转染的大鼠肾上腺嗜铬细胞瘤(PC 12)细胞系。方法人工设计、合成针对SERCA基因干扰序列,退火后连接到PGLV3干扰载体上,与p Gag/Pol、pRev、p VSV-G共转染293T细胞,包装产生慢病毒颗粒并测定病毒滴度,感染PC 12细胞,建立稳定细胞株;应用RT-PCR和Western blot技术检测PC 12稳定细胞中SERCA基因和蛋白表达情况,并与对照组进行比较。结果成功构建了针对SERCA基因的RNAi慢病毒表达载体,病毒滴度为3×108U·m L-1;建立稳定转染的PC 12细胞株。有效干扰验证显示,sh SERCA能明显降低SERCA的mRNA及蛋白水平(P<0.01)。结论成功构建SERCA基因的sh SERCA慢病毒表达载体,建立稳定干扰SERCA表达的PC 12细胞株。

SERCA2a基因治疗慢性心力衰竭的研究进展

慢性心力衰竭(chronic heart failure,CHF)是心血管疾病的主要原因之一,也是65岁以上老年人住院的主要原因,据估计,目前全世界每年治疗心力衰竭的医疗费用将近千亿美元,因此找到可以延缓和逆转CHF进展的治疗方法是临床研究方向之一。心力衰竭过程中心肌Ca^2+的调节出现严重异常,是导致心力衰竭的一个非常重要的病理原因,也是CHF的一个重要特征。正常心肌细胞内Ca^2+的浓度受到严格调控,可有效控制心肌收缩和舒张功能。在调控心肌细胞内Ca^2+信号的调控网络的许多细胞表面蛋白和胞内细胞器中,肌浆网/内质网Ca^2+-ATP酶-2a(sarco/endoplasmic reticulum Ca^2+-ATPase type 2a,SERCA2a)在心肌Ca^2+调控中起着十分重要的作用。SERCA2a可以将胞浆中的Ca^2+摄入到肌浆网中,使胞浆中Ca^2+水平下降,使肌动蛋白-肌球蛋白解偶联,从而实现心室舒张。越来越多的证据表明SERCA2a在CHF中的表达下调,进而导致严重的收缩和舒张功能障碍。因此,恢复SERCA2a的表达,改善和恢复心肌细胞对Ca^2+的调控能力,为目前研究治疗CHF提供一种很好的选择。随着科技的进步,安全有效的基因传递技术的进步已经让SERCA2a基因治疗作为CHF患者潜在的选择之一。因此,现对SERCA2a基因治疗进行综述,从最开始的质粒模型和动物模型,到后来在CHF患者中的临床试验进展,为临床研究提供参考。

The substitution of SERCA2 redox cysteine 674 promotes pulmonary vascular remodeling by activating IRE1α/XBP1s pathway

Pulmonary hypertension(PH) is a life-threatening disease characterized by pulmonary vascular remodeling, in which hyperproliferation of pulmonary artery smooth muscle cells(PASMCs)plays an important role. The cysteine 674(C674) in the sarcoplasmic/endoplasmic reticulum Ca^(2+)ATPase 2(SERCA2) is the critical redox regulatory cysteine to regulate SERCA2 activity. Heterozygous SERCA2 C674 S knock-in mice(SKI), where one copy of C674 was substituted by serine to represent partial C674 oxidative inactivation, developed significant pulmonary vascular remodeling resembling human PH, and their right ventricular systolic pressure modestly increased with age. In PASMCs, substitution of C674 activated inositol requiring enzyme 1 alpha(IRE1 a) and spliced X-box binding protein 1(XBP1 s) pathway, accelerated cell cycle and cell proliferation, which reversed by IRE1 a/XBP1 s pathway inhibitor 4μ8 C. In addition, suppressing the IRE1 a/XBP1 s pathway prevented pulmonary vascular remodeling caused by substitution of C674. Similar to SERCA2 a, SERCA2 b is also important to restrict the proliferation of PASMCs. Our study articulates the causal effect of C674 oxidative inactivation on the development of pulmonary vascular remodeling and PH, emphasizing the importance of C674 in restricting PASMC proliferation to maintain pulmonary vascular homeostasis. Moreover, the IRE1 a/XBP1 s pathway and SERCA2 might be potential targets for PH therapy.

Gene Expressions Underlying Mishandled Calcium Clearance and Elevated Generation of Reactive Oxygen Species in the Coronary Artery Smooth Muscle Cells of Chronic Heart Failure Rats

Background： The calcium clearance and reactive oxygen species （ROS） generations in the coronary artery smooth muscle cells in chronic heart failure （HF） have not been fully investigated. Therefore, we attempted to understand the gene expressions underlying the mishandling of calcium clearance and the accumulations of ROS. Methods： We initially established an animal model of chronic HF by making the left anterior descending coronary artery ligation （CAL） in rats, and then isolated the coronary artery vascular smooth muscle cells from the ischemic and the nonischemic parts of the coronary artery vessels in 12 weeks after CAL operation. The intracellular calcium concentration and ROS level were measured using flow cytometry, and the gene expressions of sarco/endoplasmic reticulum Ca2＋-ATPase （SERCA2a）, encoding sarcoplasmic reticulum Ca2＋-ATPase 2a, encoding sodium-calcium exchanger （NCX）, andp47phox encoding a subunit of the nicotinamide adenine dinucleotide phosphate （NADPH） oxidase were examined using real-time quantitative reverse transcription polymerase chain reaction and Western blotting, respectively. Results： We found that the calcium accumulation and ROS generation in the coronary artery smooth muscle cells isolated from either the ischemic or the nonischemic part of the CAL coronary artery vessel were significantly increased irrespective of blood supply （all P 〈 0.01 ）. Moreover, these were accompanied by the increased expressions of NCX and p47phox, the decreased expression of S ERCA2a, and the increased amount of phosphorylated forms of p47phox in NADPH oxidase （all P 〈 0.05）. Conclusions： Our results demonstrated that the disordered calcium clearance and the increased ROS generation occurred in the coronary artery smooth muscle cells in rats with chronic HF produced by ligation of the left anterior descending coronary artery （CAL）, and which was found to be disassociated from blood supply, and the increased generation of ROS in the ceils was found to make concomitancy to the increased activity of NADPH oxidase in cytoplasm.

A Comparative Study on the Therapeutic Effect of Astragaloside (黄芪总皂甙) and Perindopril in Treating CVB_3-Infected Cardiomyocytes in Rats

Objective: To compare the therapeutic effects of Astragaloside and Perindopril on myocardial sarco/endoplasmic reticulum Ca 2+ ATPase (SERCA) activity and the SERCA type 2 mRNA level in Coxsackievirus B 3 (CVB 3) infected cardiomyocytes. Methods: Cultured cardiomyocytes of rats were divided into normal, model, Astragaloside and Perindopril groups. The model, Astragaloside and Perindopril groups were infected with CVB 3. Meanwhile, the Astragaloside and the Perindopril groups were treated with Astragaloside (10 μg/ml) and Perindopril (1.3 μg/ml) respectively. Cytopathic effect (CPE), cardiac troponin I ( cTnI) , the SERCA activity and mRNA level of the SERCA type 2 were observed after 96 hours. Results: The CPE and cTnI of model group were significantly higher than those of normal, Astragaloside and Perindopril groups ( P <0.01). The activity and the mRNA expression of myocardial SERCA of model group were significantly lower than those of normal, Astragaloside and Perindopril groups ( P <0.01-0.05). Compared with Astragaloside group, the CPE, cTnI of Perindopril group were higher and the activity and mRNA level of Perindopril group were lower. But there were no significant difference between the two groups ( P >0.05). Conclusion: Astragaloside and Perindopril were able to reverse the down regulations of cardiac SERCA activity and mRNA expression caused by virus infection to alleviate the cardiomyocyte injury.

Spontaneous Neurotransmitter Release Depends on Intracellular Rather than ER Calcium Stores in Cultured Xenopus NMJ

Calcium ions are important in many vital neuron processes, including spontaneous neurotransmitter release. Extracellular calcium has long been known to be related to spontaneous neurotransmitter release, but the detailed mechanism for the effect of intracellular Ca^2＋ on synaptic release has not yet been understood. In this research, 1,2-bis-（o-aminophenoxy）-ethane-N, N, N′, N′-tetraacetic acid tetraacetoxymethyl ester （BAPTA-AM） was used to combine with cytosolic free Ca^2＋ in a calcium free medium of cultured Xenopus neuromuscular junctions （NMJ）, The spontaneous synaptic current （SSC） frequency was obviously reduced. Then, drugs were applied to interrupt and activate the Ca2＋ release channels in the endoplasmic reticulum （ER） membrane, but the SSC frequency was not affected. The results show that spontaneous neurotransmitter release depends on intracellular rather than ER calcium in cultured Xenopus NMJ without extracellular calcium.