Rationale: Cardiac fibrosis is associated with various cardiovascular diseases and can eventually lead to heart failure. Dysregulation of long non-coding RNAs (lncRNAs) has recently been recognized as one of the key mechanisms involved in cardiac diseases. However, the potential roles and underlying mechanisms of lncRNAs in cardiac fibrosis have not been explicitly delineated.Methods and Results: Using a combination of in vitro and in vivo studies, we identified a lncRNA NONMMUT022555, which is designated as a pro-fibrotic lncRNA (PFL), and revealed that PFL is up-regulated in the hearts of mice in response to myocardial infarction (MI) as well as in the fibrotic cardiac fibroblasts (CFs). We found that knockdown of PFL by adenoviruses carrying shRNA attenuated cardiac interstitial fibrosis and improved ejection fraction (EF) and fractional shortening (FS) in MI mice. Further study showed that forced expression of PFL promoted proliferation, fibroblast-myofibroblast transition and fibrogenesis in mice CFs by regulating let-7d, whereas silencing PFL mitigated TGF-β1-induced myofibroblast generation and fibrogenesis. More importantly, PFL acted as a competitive endogenous RNA (ceRNA) of let-7d, as forced expression of PFL reduced the expression and activity of let-7d. Moreover, let-7d levels were decreased in the MI mice and in fibrotic CFs. Inhibition of let-7d resulted in fibrogenesis in CFs, whereas forced expression of let-7d abated fibrogenesis through targeting platelet-activating factor receptor (Ptafr). Furthermore, overexpression of let-7d by adenoviruses carrying let-7d precursor impeded cardiac fibrosis and improved cardiac function in MI mice.Conclusion: Taken together, our study elucidated the role and mechanism of PFL in cardiac fibrosis, indicating the potential role of PFL inhibition as a novel therapy for cardiac fibrosis.

More evidence is emerging of the roles long non-coding RNAs (lncRNAs) play as regulatory factors in a variety of biological processes, but the mechanisms underlying the function of lncRNAs in acute myocardial infarction (AMI) have not been explicitly delineated. The present study identified the lncRNA 2810403D21Rik/AK007586/Mirf (myocardial infarction-regulatory factor), that inhibited macroautophagy/ autophagy by modulating Mir26a (microRNA 26a). Inhibition of Mir26a led to cardiac injury both in vitro and in vivo, whereas overexpression of Mir26a attenuated ischemic stress-induced cell death by activating autophagy through targeting Usp15 (ubiquitin specific peptidase 15). More importantly, 2810403D21Rik/Mirf acted as a competitive endogenous RNA (ceRNA) of Mir26a; forced expression of 2810403D21Rik/Mirf downregulated Mir26a to inhibit autophagy. In contrast, loss of 2810403D21Rik/Mirf resulted in upregulation of Mir26a to promote autophagy and alleviate cardiac injury, which in turn improved cardiac function in MI mice. This study identified a lncRNA 2810403D21Rik/Mirf that functions as an anti-autophagic molecule via ceRNA activity toward Mir26a. Our findings suggest that knockdown of 2810403D21Rik/Mirf might be a novel therapeutic approach for cardiac diseases associated with autophagy.

Experimental allergic encephalomyelitis is a T-cell-mediated, major histocompatibility complex (MHC) MATERIALS AND METHODS Mice. Female SJL/J mice were purchased from The Jackson Laboratory and were used between 8 and 12 weeks of age.Antigens. Peptides of MBP and PLP corresponding to amino acids 1-14, 91-103, and 139-151 were synthesized by solid-phase 9-fluorenylmethoxycarbonyl (FMOC) procedures. Peptides were purified by reverse-phase HPLC and were characterized by both HPLC and mass spectroscopy.Purification of dass H MHC. I-Al protein was purified from a Nonidet P-40 extract of spleen cell membranes from SJL/J mice by affinity chromatography using the monoclonal antibody 10-2.16 (specific for I-Ak and I-Al), coupled to Sepharose 4B beads. Extracted lysate from the high-speed (100,000x g) membrane fraction in a buffer of 10 mM Tris HCI, pH 8.3/0.5% Nonidet P-40/0.1 M sodium chloride/5 mM EDTA/0.02% sodium azide/1 mM phenylmethylsulfonyl fluoride was recycled over the preequilibrated column at 40C for 16 hr. The column was washed first with 10 bed volumes of deoxycholate buffer/10 mM Tris-HCl, pH 8.3/0.5% deoxycholate/0.1 M sodium chloride/5 mM EDTA/0.02% sodium azide/1 mM phenylmethylsulfonyl fluoride and then by 5 bed volumes of phosphate-buffered saline (PBS)/1% 1-octyl P-Dglycopyranoside buffer. Finally, I-AS was eluted with 20 mM phosphate buffer, pH 11/0.1 M sodium chloride/1% octyl glucoside/0.02% sodium azide/1 mM phenylmethylsulfonyl fluoride. Fractions were neutralized with acetic acid to a final Abbreviations: EAE, experimental allergic encephalomyelitis; MBP, myelin basic protein; PLP, proteolipoprotein; MHC, major histocompatibility complex. tTo whom reprint requests should be addressed. 11465The publication costs of this article were defrayed in part by page charge payment. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. §1734 solely to indicate this fact.