Recent studies have begun to reveal critical roles of microRNAs (miRNAs) in the pathogenesis of cardiac hypertrophy and dysfunction. In this study, we tested whether a transforming growth factor-β (TGF-β)-regulated miRNA played a pivotal role in the development of cardiac hypertrophy and heart failure (HF). We observed that miR-27b was upregulated in hearts of cardiomyocyte-specific Smad4 knockout mice, which developed cardiac hypertrophy. In vitro experiments showed that the miR-27b expression could be inhibited by TGF-β1 and that its overexpression promoted hypertrophic cell growth, while the miR-27b suppression led to inhibition of the hypertrophic cell growth caused by phenylephrine (PE) treatment. Furthermore, the analysis of transgenic mice with cardiomyocyte-specific overexpression of miR-27b revealed that miR-27b overexpression was sufficient to induce cardiac hypertrophy and dysfunction. We validated the peroxisome proliferator-activated receptor-γ (PPAR-γ) as a direct target of miR-27b in cardiomyocyte. Consistently, the miR-27b transgenic mice displayed significantly lower levels of PPAR-γ than the control mice. Furthermore, in vivo silencing of miR-27b using a specific antagomir in a pressure-overload-induced mouse model of HF increased cardiac PPAR-γ expression, attenuated cardiac hypertrophy and dysfunction. The results of our study demonstrate that TGF-β1-regulated miR-27b is involved in the regulation of cardiac hypertrophy, and validate miR-27b as an efficient therapeutic target for cardiac diseases.
Progranulin (PGRN), an autocrine growth factor, has multiple physiological functions and is widely involved in the pathogenesis of many types of diseases. The pivotal anti-inflammatory function of PGRN in rheumatoid arthritis encouraged us to examine the role of PGRN in acute kidney injury (AKI). We found that levels of PGRN were significantly reduced in the kidney in a mouse model of renal ischemia/reperfusion injury. We also observed that PGRN deficiency (Grn(-/-) mice) significantly aggravated renal injury as evidenced by higher serum creatinine, more severe morphological injury, increased tubular epithelial cell death, and tubulointerstitial neutrophil and macrophage infiltration versus wild-type mice. In vitro, we found that recombinant human PGRN attenuated hypoxia-induced inflammatory actions and apoptosis in proximal tubule epithelial cells, at least in part associated with a nucleotide-binding oligomerization domain containing 2 (NOD2)-mediated immune response. Importantly, pretreatment with or delayed administration of recombinant human PGRN protected against or promoted recovery from renal ischemia/reperfusion injury in wild-type and Grn(-/-) mice. Similar protective effects were also found in cisplatin-induced AKI. Thus, our findings provide a better understanding of the biological activities of PGRN in the kidney and suggest that PGRN may be an innovative therapeutic strategy for treating patients with AKI.
Lung cancer (LC) is a leading cause of cancer‐related death in the Western world. Patients with LC usually have poor prognosis due to the difficulties in detecting tumors at early stages. Multiple studies have shown that circulating miRNAs might be promising biomarkers for early detection of LC. We aimed to provide an overview of published studies on circulating miRNA markers for early detection of LC and to summarize their diagnostic performance in Western populations. A systematic literature search was performed in PubMed and ISI Web of Knowledge to find relevant studies published up to 11 August 2017. Information on study design, population characteristics, miRNA markers, and diagnostic accuracy (including sensitivity, specificity, and AUC) were independently extracted by two reviewers. Overall, 17 studies evaluating 35 circulating miRNA markers and 19 miRNA panels in serum or plasma were included. The median sensitivity (range) and specificity (range) were, respectively, 78.4% (51.7%‐100%) and 78.7% (42.9%‐93.5%) for individual miRNAs, and 83.0% (64.0%‐100%) and 84.9% (71.0%‐100%) for miRNA panels. Most studies incorporated individual miRNA markers as panels (with 2‐34 markers), with multiple miRNA‐based panels generally outperforming individual markers. Two promising miRNA panels were discovered and verified in prospective cohorts. Of note, both studies exclusively applied miRNA ratios when building up panels. In conclusion, circulating miRNAs may bear potential for noninvasive LC screening, but large studies conducted in screening or longitudinal settings are needed to validate the promising results and optimize the marker panels.
Arrhythmogenesis in acute myocardial infarction (MI) is associated with depolarization of resting membraine potential (RMP) and decrease of inward rectifier potassium current (IK1) in cardiomyocytes. However, clinical anti-arrhythmic agents that primarily act on RMP by enhancing the IK1 channel are not currently available. We hypothesized that zacopride, a selective and moderate agonist of the IK1/Kir2.1 channels, prevents and cures acute ischemic arrhythmias. To test this viewpoint, adult Sprague-Dawley (SD) rats were subjected to MI by ligating the left main coronary artery. The antiarrhythmic effects of zacopride (i.v. infusion) were observed in the settings of pre-treatment (zacopride given 3 min prior to coronary occlusion), post-treatment (zacopride given 3 min after coronary occlusion) and therapeutic treatment (zacopride given 30 s after the onset of the first sustained ventricular tachycardia (VT)/ventricular fibrillation (VF) post MI). In all the three treatment modes, zacopride (15 μg/kg) inhibited MI-induced ventricular tachyarrhythmias, as shown by significant decreases in the premature ventricular contraction (PVC) and the duration and incidence of VT or VF. In Langendorff perfused rat hearts, the antiarrhythmic effect of 1 μmol/L zacopride were reversed by 1 μmol/L BaCl2, a blocker of IK1 channel. Patch clamp results in freshly isolated rat ventricular myocytes indicated that zacopride activated the IK1 channel and thereby reversed hypoxia-induced RMP depolarization and action potential duration (APD) prolongation. In addition, zacopride (1 μmol/L) suppressed hypoxia- or isoproterenol- induced delayed afterdepolarizations (DADs). In Kir2.x transfected Chinese hamster ovary (CHO) cells, zacopride activated the Kir2.1 homomeric channel but not the Kir2.2 or Kir2.3 channels. These results support our hypothesis that moderately enhancing IK1/Kir2.1 currents as by zacopride rescues ischemia- and hypoxia- induced RMP depolarization, and thereby prevents and cures acute ischemic arrhythmias. This study brings a new viewpoint to antiarrhythmic theories and provides a promising target for the treatment of acute ischemic arrhythmias.
Background: Epigenetic abnormalities are increasingly observed in multiple malignancies, including epithelial ovarian cancer (EOC), and their effects can be significantly counteracted by tumor-suppressor microRNAs, namely epi-miRNAs. Here, we investigated the role of miR-29b, a well-established epi-miRNA, in the DNA methylation regulation of EOC cells. Methods: The correlation between miR-29b and DNMT3A/3B expression was evaluated by RT-qPCR, western blotting and immunohistochemical analysis. The functional roles of miR-29b and DNMT3A/3B were tested by anti-miRs and microRNA precursors. A luciferase reporter assay was employed to detect the direct binding of miR-29b to DNMT3A/3B 3′ UTRs. Co-IP was utilized for investigating Id-1 binding activity. Results: miR-29b was negatively correlated with DNMT3A/3B expression at the cellular/histological levels. miR-29b silencing was correlated with increased DNMT3A/3B levels, whereasmiR-29b over-expression caused DNMT3A/3B down-regulation. Luciferase reporter assays confirmed that the miR-29b-mediated downregulation of DNMT3A/3Boccurred through the direct targeting of theirmRNAs'3'-UTRs,whereasBGS assays found that DNMT3A/3B knockdown increased miR-29b expression via CpG island promoter hypomethylation, thus suggesting a crucial crosstalk betweenmiR-29b and DNMT3A/3B via a double-negative feedback loop. Co-IP assay confirmed direct binding between DNMT3A and Id-1. Conclusion: Taken together, our study sheds light on a novel epigenetic circuitry regulating EOC progression and may provide novel options for miR-29b-based epi-therapeutic approaches for future EOC treatment.Y. Teng and X. Zuo and M. Hou contributed equally to this article.
TRT combined with ChT could provide a survival benefit to elderly patients with ES-SCLC.
Tight junction (TJ) proteins play a dynamic role in paracellular fluid transport in salivary gland epithelia. Most TJ studies are carried out in mice and rats. However, the morphology of rodent salivary glands differs from that of human glands. This study aimed to compare the histological features and the expression pattern of TJ proteins in porcine salivary glands with those of human and mouse. The results showed that porcine parotid glands were pure serous glands. Submandibular glands (SMGs) were serous acinar cell-predominated mixed glands, whereas sublingual glands were mucous acinar cell-predominated. Human SMGs were mixed glands containing fewer mucous cells than porcine SMGs, whereas the acinar cells of murine SMGs are seromucous. The histological features of the duct system in the porcine and human SMGs were similar and included intercalated, striated and excretory ducts, but the murine SMG contained a specific structure, the granular convoluted tubule. TJ proteins, including claudin-1 to claudin-12, occludin and zonula occludin-1 (ZO-1), were detected in the porcine major salivary glands and human SMGs by RT-PCR; however, claudin-6, claudin-9 and claudin-11 were not detected in the murine SMG. As shown by immunofluorescence, claudin-1, claudin-3, claudin-4, occludin and ZO-1 were distributed in both acinar and ductal cells in the porcine and human SMGs, whereas claudin-1 and claudin-3 were mainly present in acinar cells, and claudin-4 was mainly distributed in ductal cells in the murine SMG. In addition, 3D images showed that the TJ proteins arranged in a honeycomb-like structure on the luminal surface of the ducts, whereas their arrangements in acini were irregular in porcine SMGs. In summary, the expression pattern of TJ proteins in salivary glands is similar between human and miniature pig, which may be a candidate animal for studies on salivary gland TJ function.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.