Ao Zhang

Bio: Ao Zhang is an academic researcher from New York University. The author has contributed to research in topics: Microvesicles & Heart failure. The author has an hindex of 8, co-authored 13 publications receiving 201 citations. Previous affiliations of Ao Zhang include Tianjin University.

Long Noncoding RNAs in Pathological Cardiac Remodeling: A Review of the Update Literature.

Abstract: Cardiac remodeling is a self-regulatory response of the myocardium and vasculature under the stressful condition. Cardiomyocytes (CMs), vascular smooth muscle cells (VSMCs), endothelial cells (ECs), and cardiac fibroblasts (CFs) are all involved in this process, characterized by change of morphological structures and mechanical/chemical activities as well as metabolic patterns. Despite current development of consciousness, the control of cardiac remodeling remains unsatisfactory, and to further explore the underlying mechanism and seek the optimal therapeutic targets is still the urgent need in clinical practice. It is now emerging that long noncoding RNAs (lncRNAs) play key regulatory roles in these adverse responses: lncRNA TUG1, AK098656, TRPV1, GAS5, Giver, and Lnc-Ang362 have been indicated in hypertension-related vascular remodeling, H19, TUG1, UCA1, MEG3, APPAT, and lincRNA-p21 in atherosclerosis (AS), and HIF1A-AS1 and Lnc-HLTF-5 in aortic aneurysm (AA). In addition, Neat1, AK139328, APF, CAIF, AK088388, CARL, MALAT1, HOTAIR, XIST, and NRF are involved in postischemia myocardial remodeling, while Mhrt, Chast, CHRF, ROR, H19, Plscr4, and MIAT are involved in myocardial hypertrophy, and MALAT1, wisper, MEG3, and H19 are involved in extracellular matrix (ECM) reconstitution. Signaling to specific miRNAs by acting as endogenous sponge (ceRNA) was the main form that regulates the target gene expression during cardiac remodeling. This review will underline the updates of lncRNAs and lncRNA-miRNA interactions in maladaptive remodeling and also cast light on their potential roles as therapeutic targets, hoping to provide supportive background for following research.

Role and Effective Therapeutic Target of Gut Microbiota in Heart Failure

Abstract: Although the mechanism of the occurrence and development of heart failure has been continuously explored in the past ten years, the mortality and readmission rate of heart failure is still very high. Modern studies have shown that gut microbiota is associated with a variety of cardiovascular diseases, among which the study of gut microbiota and heart failure attracts particular attention. Therefore, understanding the role of gut microbiota in the occurrence and development of heart failure will help us further understand the pathogenesis of heart failure and provide new ideas for its treatment. This paper introduced intestinal flora and its metabolites, summarized the changes of intestinal flora in patients with heart failure, clarified that intestinal barrier damage and bacterial translocation induced inflammation and immune response aggravated heart failure, and altered intestinal microflora affected various metabolic pathways including trimethylamine/TMAO, SCFA, and Bile acid pathway leads to heart failure. At the same time, regulating intestinal microflora through diet, probiotics, antibiotics, fecal transplantation and microbial enzyme inhibitors has grown up to be a potential treatment for many metabolic disorders.

The microRNA in ventricular remodeling: the miR-30 family.

Abstract: Ventricular remodeling (VR) is a complex pathological process of cardiomyocyte apoptosis, cardiac hypertrophy, and myocardial fibrosis, which is often caused by various cardiovascular diseases (CVDs) such as hypertension, acute myocardial infarction, heart failure (HF), etc. It is also an independent risk factor for a variety of CVDs, which will eventually to damage the heart function, promote cardiovascular events, and lead to an increase in mortality. MicroRNAs (miRNAs) can participate in a variety of CVDs through post-transcriptional regulation of target gene proteins. Among them, microRNA-30 (miR-30) is one of the most abundant miRNAs in the heart. In recent years, the study found that the miR-30 family can participate in VR through a variety of mechanisms, including autophagy, apoptosis, oxidative stress, and inflammation. VR is commonly found in ischemic heart disease (IHD), hypertensive heart disease (HHD), diabetic cardiomyopathy (DCM), antineoplastic drug cardiotoxicity (CTX), and other CVDs. Therefore, we will review the relevant mechanisms of the miR-30 in VR induced by various diseases.

RNA delivery by extracellular vesicles in mammalian cells and its applications.

Abstract: The term 'extracellular vesicles' refers to a heterogeneous population of vesicular bodies of cellular origin that derive either from the endosomal compartment (exosomes) or as a result of shedding from the plasma membrane (microvesicles, oncosomes and apoptotic bodies). Extracellular vesicles carry a variety of cargo, including RNAs, proteins, lipids and DNA, which can be taken up by other cells, both in the direct vicinity of the source cell and at distant sites in the body via biofluids, and elicit a variety of phenotypic responses. Owing to their unique biology and roles in cell-cell communication, extracellular vesicles have attracted strong interest, which is further enhanced by their potential clinical utility. Because extracellular vesicles derive their cargo from the contents of the cells that produce them, they are attractive sources of biomarkers for a variety of diseases. Furthermore, studies demonstrating phenotypic effects of specific extracellular vesicle-associated cargo on target cells have stoked interest in extracellular vesicles as therapeutic vehicles. There is particularly strong evidence that the RNA cargo of extracellular vesicles can alter recipient cell gene expression and function. During the past decade, extracellular vesicles and their RNA cargo have become better defined, but many aspects of extracellular vesicle biology remain to be elucidated. These include selective cargo loading resulting in substantial differences between the composition of extracellular vesicles and source cells; heterogeneity in extracellular vesicle size and composition; and undefined mechanisms for the uptake of extracellular vesicles into recipient cells and the fates of their cargo. Further progress in unravelling the basic mechanisms of extracellular vesicle biogenesis, transport, and cargo delivery and function is needed for successful clinical implementation. This Review focuses on the current state of knowledge pertaining to packaging, transport and function of RNAs in extracellular vesicles and outlines the progress made thus far towards their clinical applications.

Innate and adaptive humoral responses coat distinct commensal bacteria with immunoglobulin A

Abstract: Immunoglobulin A (IgA) is prominently secreted at mucosal surfaces and coats a fraction of the intestinal microbiota However, the commensal bacteria bound by IgA are poorly characterized and the type of humoral immunity they elicit remains elusive We used bacterial flow cytometry coupled with 16S rRNA gene sequencing (IgA-Seq) in murine models of immunodeficiency to identify IgA-bound bacteria and elucidate mechanisms of commensal IgA targeting We found that residence in the small intestine, rather than bacterial identity, dictated induction of specific IgA Most commensals elicited strong T-independent (TI) responses that originated from the orphan B1b lineage and from B2 cells, but excluded natural antibacterial B1a specificities Atypical commensals including segmented filamentous bacteria and Mucispirillum evaded TI responses but elicited T-dependent IgA These data demonstrate exquisite targeting of distinct commensal bacteria by multiple layers of humoral immunity and reveal a specialized function of the B1b lineage in TI mucosal IgA responses

Abstract 3177: Ischemic Preconditioning Augments Survival of Stem Cells via miR-210 Expression by Targeting Caspase 8-Associated Protein 2

Abstract: MicroRNAs (miRs) participate in most cellular functions by posttranscriptional regulation of gene expression albeit with little information regarding their role in ischemic preconditioning (IP) of stem cells. We report that IP of bone marrow-derived mesenchymal stem cells (MSCs) with two cycles of 30-min ischemia/reoxygenation (I/R) supported their survival under subsequent longer exposure to anoxia and following engraftment in the infarcted heart. IP significantly reduced apoptosis in MSCs through activation of Akt (Ser473) and ERK1/2 (Thr202/Tyr204) and nuclear translocation of hypoxia-inducible factor-1α (HIF-1α). We observed concomitant induction of miR-210 in the preconditioned MSCs (PCMSCs). Inhibition of HIF-1α or of miR-210 abrogated the cytoprotective effects of preconditioning. Extrapolation of these data to in vivo studies in a rat model of acute myocardial infarction predominantly improved stem cell survival after engraftment with a role for miR-210. Notably, multiple I/R cycles more effectively regulated the miR-210 and hence promoted MSC survival compared with single-cycle hypoxia of an equal duration. Real time PCR array for rat apoptotic genes, computational target gene analyses, and luciferase reporter assay identified FLICE-associated huge protein (FLASH)/caspase-8-associated protein-2 (Casp8ap2) in PCMSCs as the target gene of miR-210. Induction of FLASH/CASP8AP2 in miR-210 knocked-down PCMSCs resulted in increased cell apoptosis. Taken together, these data demonstrated that cytoprotection afforded by IP was regulated by miR-210 induction via FLASH/Casp8ap2 suppression. These results highlighted that IP by multiple short episodes of I/R is a novel strategy to promote stem cell survival.