间充质干细胞来源的外泌体在炎症性肠病治疗中的作用机制及应用前景

炎症性肠病(IBD)是一种原因不明的非特异性肠道疾病,其发病率逐年提高,目前治疗药物疗效有限。间充质干细胞(MSCs)具有免疫调节、抗炎等功能,有望成为IBD的新兴治疗手段。然而MSCs因归巢能力有限,目前认为其可能通过旁分泌发挥治疗作用。MSCs分泌的外泌体(MSCs-Exo)具有MSCs的大部分功能,无恶性分化且在体内稳定存在,在干细胞治疗领域具有重要研究价值,但其在IBD中的作用机制尚不明确。本文将就MSCs-Exo对IBD的作用机制以及在IBD中的应用前景进行综述。     

Ferroptosis与糖尿病性心肌病

糖尿病性心肌病(diabetic cardiomyopathy,DCM)是一种由长期糖尿病引起的心肌病，其发病不伴随高血压、冠心病等其他心脏危险因素，是糖尿病的一种常见临床并发症，由代谢紊乱引起，可产生心律失常和心力衰竭，严重时可导致死亡，并伴有微血管病变的广泛局灶性心肌细胞死亡。Ferroptosis是一种细胞程序性死亡方式，主要由氧化应激、铁代谢和脂质代谢异常等因素诱发。在DCM发病过程中，存在心肌细胞糖脂代谢异常，并伴随着氧化应激导致心肌细胞Ferroptosis。本文针对近些年来DCM Ferroptosis相关的研究，综述了Ferroptosis和DCM之间的关系以及可能的机制，为探究DCM发生机制和干预治疗提供一定的理论依据。     

糖尿病心肌病发病机制的研究进展

糖尿病心肌病（diabetic cardiomyopathy, DCM）是一种特殊类型的心脏疾病，在一定程度上增加了糖尿病患者发生心力衰竭的风险，也是糖尿病患者死亡的主要原因之一。DCM的发病机制涉及多个方面，心肌细胞代谢紊乱（如高血糖和胰岛素抵抗）、心肌炎症和纤维化是DCM发病的基础，这些因素单独或联合作用于DCM的发生和发展。目前临床上尚无根治DCM的有效药物，研究疾病的发病机制在开发靶向治疗药物中具有重要意义。主要对当前DCM发病机制的研究进展展开综述，以期为DCM的早期预防和治疗提供理论基础。     

间充质干细胞在结核病治疗中的研究进展

间充质干细胞(mesenchymal stem cells, MSCs)是一种多能干细胞,具有自我更新、多向分化、免疫调节和抗炎的能力,在组织修复和再生中发挥着重要作用。已有临床前和临床研究证明,MSCs在治疗结核病(tuberculosis, TB)方面具有潜在的应用价值。因此,了解MSCs的生物学和免疫学特性,对规范和优化基于MSCs的再生治疗具有重要意义。现重点介绍MSCs在TB中的作用机制以及基于MSCs在TB临床试验的最新进展。     

间充质干细胞的特性与分化诱导研究进展

间充质干细胞(MSCs)是成体干细胞的一种, 广泛存在于人体的间充质组织中, 具有自我复制能力和多项分化潜能. 单独或联合使用某些细胞因子、生长因子、激素、维生素、抗氧化剂和抗肿瘤药物等, 可诱导MSCs在体外培养条件下向某一谱系细胞分化. 鉴于MSCs的上述特点, 使其有着非常诱人的临床应用前景, 可以用于许多种疾病的治疗. 本文从MSCs的生物学特性、MSCs的分化诱导、分化调节机制及应用前景等方面进行了评述.     

骨髓间充质干细胞抗肝纤维化的研究进展

肝纤维化及其终末病变肝硬化已严重危害全球人类健康,虽然慢性肝病的治疗手段和抗肝纤维化药物的研究已取得了很大进展,肝移植依然是最有效的治疗方案,但器官的紧缺却是一个现实问题。目前寻找有效的干预手段进行抗肝纤维化治疗已越来越受到大家的关注。近些年,大量基础及临床研究均证实在一定条件下利用骨髓间充质干细胞(MSCs)可以抑制肝星状细胞活化诱导其凋亡,实现肝纤维化逆转。随着干细胞技术的快速发展,基于骨髓间充质干细胞(MSCs)的细胞疗法在肝纤维化治疗领域的研究与应用已成为一个充满生命力的新方向。本文将对肝纤维化及基于MSCs的治疗机制进展及其应用进行综述。     

基于网络药理学和分子对接研究黄芪治疗糖尿病心肌病的作用机制

目的:运用网络药理学和分子对接方法研究黄芪治疗糖尿病心肌病(DCM)的作用机制.方法:利用中药系统药理学技术平台数据库(TCMSP)收集黄芪的成分及其相关靶点;通过GeneCards、NCBI、OMIM数据库获取DCM相关疾病靶点.取黄芪成分靶点与DCM疾病靶点的交集基因,作为黄芪对DCM作用的潜在关键靶点基因,将交集...     

间充质干细胞移植治疗帕金森病的作用机制研究进展

帕金森病(Parkinson’s Disease,PD)的主要病理改变是黑质多巴胺能神经元进行性变性致纹状体多巴胺递质浓度显著降低,从而出现运动障碍。目前,药物和外科手术治疗可一定程度改善早期PD的部分临床症状,但并不能阻止或逆转多巴胺能神经元变性。近些年,间充质干细胞(Mesenchymal Stem Cells,MSCs)移植作为治疗PD的最前沿方法,其疗效备受瞩目。本文就MSCs移植促进PD神经功能恢复的可能作用机制作一综述。     

间充质干细胞来源外泌体促心肌梗死血管新生及其机制研究进展

血管新生(angiogenesis)是机体内一个复杂的生理学和病理学过程,是治疗缺血性疾病的重要措施。大量实验研究已表明间充质干细胞(mesenchymal stem cells, MSCs)等干细胞移植可促进心肌梗死后血管新生,近期研究证实这一作用可能主要通过分泌外泌体形式介导。外泌体(exosome)通过传递与血管新生相关微RNA(microRNA, mi RNA)或蛋白质等生物活性物质,调控靶器官中与血管新生相关通路的基因表达,提高内皮细胞在缺血缺氧环境下的存活、迁移、成管能力,促进心肌梗死区域血管新生。通过基因修饰手段增强外泌体介导的心脏修复作用,以及将外泌体与生物活性肽结合形成工程外泌体来靶向缺血心肌治疗,是目前外泌体在心血管领域的热点研究方向。本文结合近年外泌体研究的相关文献,就MSCs来源外泌体促进心肌梗死血管新生的具体机制及现状研究作一综述。     

间充质干细胞治疗炎症性肠病的应用及前景

炎症性肠病（IBD）是一种慢性非特异性肠道炎性疾病,其病因未明,有终生复发倾向,重症者迁延不愈。早期治疗以药物为主,部分重症患者后期需要手术干预。近年来,间充质干细胞（MSCs）由于具有多向分化潜能、免疫调节及组织修复功能已被广泛应用于IBD治疗的临床前基础研究中,具有一定理论基础。在已开展的MSCs治疗IBD的临床试验中,尚未有严重并发症的报道。虽然目前MSCs治疗不是IBD的标准治疗方案,但今后可能会成为一种新的治疗选择,特别是对于难治性或合并肛瘘的IBD患者。本文就MSCs的概况及其在IBD治疗的作用机制和应用前景作一综述。     

Pathogenic roles of cardiac autoantibodies in dilated cardiomyopathy

Whether autoimmunity could cause dilated cardiomyopathy (DCM) was disputed for more than half a century. Autoantibodies against various cardiac antigens have been found in the sera of patients with DCM but none of these autoantibodies has been shown to have a substantial role in the development of DCM. It was recently reported that the injection of autoantibodies against cardiac troponin I (cTnI) can induce DCM in normal mice. This observation showed that autoantibodies can cause DCM and put an end to the controversy. Clinical trials of immunoglobulin-adsorption therapy for DCM have already started in Germany and the results seem promising. Here, we discuss the recent findings and possibilities of immunoglobulin-adsorption therapy for this deadly disease.     

Deletion of Smad3 protects against diabetic myocardiopathy in db/db mice

Diabetic cardiomyopathy (DCM) is a common diabetic complication characterized by diastolic relaxation abnormalities, myocardial fibrosis and chronic heart failure. Although TGF-β/Smad3 signalling has been shown to play a critical role in chronic heart disease, the role and mechanisms of Smad3 in DCM remain unclear. We reported here the potential role of Smad3 in the development of DCM by genetically deleting the Smad3 gene from db/db mice. At the age of 32 weeks, Smad3WT-db/db mice developed moderate to severe DCM as demonstrated by a marked increase in the left ventricular (LV) mass, a significant fall in the LV ejection fraction (EF) and LV fractional shortening (FS), and progressive myocardial fibrosis and inflammation. In contrast, db/db mice lacking Smad3 (Smad3KO-db/db) were protected against the development of DCM with normal cardiac function and undetectable myocardial inflammation and fibrosis. Interestingly, db/db mice with deleting one copy of Smad3 (Smad3 ± db/db) did not show any cardioprotective effects. Mechanistically, we found that deletion of Smad3 from db/db mice largely protected cardiac Smad7 from Smurf2-mediated ubiquitin proteasome degradation, thereby inducing IBα to suppress NF-kB-driven cardiac inflammation. In addition, deletion of Smad3 also altered Smad3-dependent miRNAs by up-regulating cardiac miR-29b while suppressing miR-21 to exhibit the cardioprotective effect on Smad3KO-db/db mice. In conclusion, results from this study reveal that Smad3 is a key mediator in the pathogenesis of DCM. Targeting Smad3 may be a novel therapy for DCM.     

Mutations of presenilin genes in dilated cardiomyopathy and heart failure

Two common disorders of the elderly are heart failure and Alzheimer disease (AD). Heart failure usually results from dilated cardiomyopathy (DCM). DCM of unknown cause in families has recently been shown to result from genetic disease, highlighting newly discovered disease mechanisms. AD is the most frequent neurodegenerative disease of older Americans. Familial AD is caused most commonly by presenilin 1 (PSEN1) or presenilin 2 (PSEN2) mutations, a discovery that has greatly advanced the field. The presenilins are also expressed in the heart and are critical to cardiac development. We hypothesized that mutations in presenilins may also be associated with DCM and that their discovery could provide new insight into the pathogenesis of DCM and heart failure. A total of 315 index patients with DCM were evaluated for sequence variation in PSEN1 and PSEN2. Families positive for mutations underwent additional clinical, genetic, and functional studies. A novel PSEN1 missense mutation (Asp333Gly) was identified in one family, and a single PSEN2 missense mutation (Ser130Leu) was found in two other families. Both mutations segregated with DCM and heart failure. The PSEN1 mutation was associated with complete penetrance and progressive disease that resulted in the necessity of cardiac transplantation or in death. The PSEN2 mutation showed partial penetrance, milder disease, and a more favorable prognosis. Calcium signaling was altered in cultured skin fibroblasts from PSEN1 and PSEN2 mutation carriers. These data indicate that PSEN1 and PSEN2 mutations are associated with DCM and heart failure and implicate novel mechanisms of myocardial disease.     

Myeloid differential protein-2 inhibition improves diabetic cardiomyopathy via p38MAPK inhibition and AMPK pathway activation

Myeloid differential protein-2 (MD2) has been shown to play a critical role in the progression of diabetic cardiomyopathy (DCM). This study aims to explore the non-inflammatory mechanisms mediated by MD2 in DCM and to test the therapeutic effects of MD2 inhibitor C30 on DCM. Streptozotocin (STZ) was used to construct DCM model in wild-type and MD2 knockout mice. The collected heart samples were subjected to RNA-sequencing assay. Gene set enrichment analysis of the RNA-seq data indicated that MD2 knockout was associated with energy metabolism pathways in diabetic mouse heart. Further data showed that AMPK pathway was impaired under high glucose condition, which was mediated by p38MAPK activation. MD2 knockout or pharmacological inhibitor C30 completely rescued AMPK signaling through p38MAPK inhibition. Importantly, C30 treatment significantly prevented myocardial damage and dysfunction in T1DM mice evidenced by improved cardiac function and reduced cardiomyocyte apoptosis and cardiac fibrosis. Furthermore, the therapeutic effect of C30 on DCM was correlated to p38MAPK inhibition and AMPK pathway activation in vivo and in vitro. In conclusion, MD2 inhibition exhibits therapeutic effects on DCM through p38MAPK inhibition and AMPK activation, which enables MD2 a promising target for DCM treatment by suppressing metaflammation and improving cardiac metabolism.     

Retracted: Upregulated microRNA-132 rescues cardiac fibrosis and restores cardiocyte proliferation in dilated cardiomyopathy through the phosphatase and tensin homolog–mediated PI3K/Akt signal transduction pathway

Cardiac fibrosis is known to be present in dilated cardiomyopathy (DCM) and it predicts the occurrence of sudden death and congestive heart failure. The aim of our study is to investigate the expression of microRNA-132 (miR-132) and its effect on cardiocyte proliferation, apoptosis, and cardiac fibrosis by binding to phosphatase and tensin homolog (PTEN) through the phosphateidylinositol 3-kinase (PI3K)/protein kinase (Akt) signal transduction pathway in DCM rats. DCM rat models induced by doxorubicin were established and confirmed by an ultrasonic cardiogram. Epithelial cells were treated with inhibitors, activators, and small interfering RNAs to identify the mechanisms by which miR-132 controls cardiocyte activity and cardiac fibrosis. Angiotensin II (Ang II) and aldosterone (ALD) expressions were detected by an enzyme-linked immunosorbent assay. The relationship between PTEN and miR-132 was verified by a dual-luciferase reporter assay. Cell proliferation and apoptosis were tested by the MTT assay and flow cytometry. PTEN was determined to be the target gene of miR-132. Rat models of DCM exhibited a lower level of miR-132, PI3K, Akt, B-cell lymphoma 2, collagen I, and collagen III, but a higher level of PTEN, Bcl-2–associated X protein, and proliferating cell nuclear antigen as well as inflammatory response (Ang II and ALD), accompanied by declined cardiocyte proliferation and elevated apoptosis and cardiac fibrosis. Upregulated miR-132 or silenced PTEN activated the PI3K/Akt pathway, thus facilitating cardiocyte proliferation and repressing cardiocyte apoptosis and cardiac fibrosis, as well as inflammatory responses. Downregulated miR-132 reversed this tendency. These findings indicate that miR-132 activates the PI3K/Akt pathway by inhibiting PTEN expression, thus facilitating cardiocyte proliferation and inhibiting apoptosis and cardiac fibrosis in DCM rats.     

A Highlights from MBoC Selection: A troponin T variant linked with pediatric dilated cardiomyopathy reduces the coupling of thin filament activation to myosin and calcium binding

Dilated cardiomyopathy (DCM) is a significant cause of pediatric heart failure. Mutations in proteins that regulate cardiac muscle contraction can cause DCM; however, the mechanisms by which molecular-level mutations contribute to cellular dysfunction are not well understood. Better understanding of these mechanisms might enable the development of targeted therapeutics that benefit patient subpopulations with mutations that cause common biophysical defects. We examined the molecular- and cellular-level impacts of a troponin T variant associated with pediatric-onset DCM, R134G. The R134G variant decreased calcium sensitivity in an in vitro motility assay. Using stopped-flow and steady-state fluorescence measurements, we determined the molecular mechanism of the altered calcium sensitivity: R134G decouples calcium binding by troponin from the closed-to-open transition of the thin filament and decreases the cooperativity of myosin binding to regulated thin filaments. Consistent with the prediction that these effects would cause reduced force per sarcomere, cardiomyocytes carrying the R134G mutation are hypocontractile. They also show hallmarks of DCM that lie downstream of the initial insult, including disorganized sarcomeres and cellular hypertrophy. These results reinforce the importance of multiscale studies to fully understand mechanisms underlying human disease and highlight the value of mechanism-based precision medicine approaches for DCM.     

Melatonin activates Parkin translocation and rescues the impaired mitophagy activity of diabetic cardiomyopathy through Mst1 inhibition

Mitophagy eliminates dysfunctional mitochondria and thus plays a cardinal role in diabetic cardiomyopathy (DCM). We observed the favourable effects of melatonin on cardiomyocyte mitophagy in mice with DCM and elucidated their underlying mechanisms. Electron microscopy and flow cytometric analysis revealed that melatonin reduced the number of impaired mitochondria in the diabetic heart. Other than decreasing mitochondrial biogenesis, melatonin increased the clearance of dysfunctional mitochondria in mice with DCM. Melatonin increased LC3 II expression as well as the colocalization of mitochondria and lysosomes in HG‐treated cardiomyocytes and the number of typical autophagosomes engulfing mitochondria in the DCM heart. These results indicated that melatonin promoted mitophagy. When probing the mechanism, increased Parkin translocation to the mitochondria may be responsible for the up‐regulated mitophagy exerted by melatonin. Parkin knockout counteracted the beneficial effects of melatonin on the cardiac mitochondrial morphology and bioenergetic disorders, thus abolishing the substantial effects of melatonin on cardiac remodelling with DCM. Furthermore, melatonin inhibited Mammalian sterile 20‐like kinase 1 (Mst1) phosphorylation, thus enhancing Parkin‐mediated mitophagy, which contributed to mitochondrial quality control. In summary, this study confirms that melatonin rescues the impaired mitophagy activity of DCM. The underlying mechanism may be attributed to activation of Parkin translocation via inhibition of Mst1.     

心肌肌钙蛋白T基因突变在心肌病发病机制中的研究进展

肥厚型和扩张型心肌病中,基因缺陷分别占发病的50％和35％,其病理生理机制,主要包括肌小节蛋白基因突变引起的收缩力产生缺陷,细胞骨架蛋白基因突变引起的收缩力传递缺陷等。心肌肌钙蛋白T将肌钙蛋白C和肌钙蛋白I连接到肌动蛋白和原肌球蛋白上,在心肌细胞收缩和舒张过程中发挥重要作用。在肥厚型和扩张型心肌病中发现了多种心肌肌钙蛋白T的基因突变,围绕心肌肌钙蛋白T的研究有助于阐明心肌病的发病机制。本文总结了心肌肌钙蛋白T基因突变在心肌病发病机制中的研究情况。