IGFBP3 epigenetic promotion induced by METTL3 boosts cardiac fibroblast activation and fibrosis.

Cardiac fibrosis remains an unresolved problem in heart disease. Its etiology is directly caused by the activation and proliferation of cardiac fibroblasts (CFs). However, there is limited information regarding the biological role of cardiac fibroblasts in cardiac fibrosis. Herein, we screened out a gene, IGFBP3, whose expression significantly increased in TGF-ß1-stimulated human primary CFs by mining RNA-Seq data for differential and WGCNA. We verified the IGFBP3's expression in transverse aortic constriction (TAC) surgery, isoproterenol (ISO)-induced cardiac fibrosis models, and TGFß1-stimulated mouse primary CFs. We also found that the knockdown of IGFBP3 could inhibit the migration and proliferation ability of CFs. Furthermore, we found that aberrant N6-methyladenosine(m6A) mRNA modifications in the animal model and activated CFs may regulate the expression of IGFBP3 in developing cardiac fibrosis. Silencing METTL3 could downregulate the expression of IGFBP3 and inhibit the activation of CFs and the degree of cardiac fibrosis both in vitro and in vivo. Indeed, we also verified the expression of METTL3 and IGFBP3 in the atrial tissues of patients with atrial fibrillation (AF). Thus, METTL3 may regulate IGFBP3's expression and CFs activation via RNA epigenetic modifications, laying the foundation for a specific and novel therapeutic target in cardiac fibrosis.

Epigenetic control of LncRNA NEAT1 enables cardiac fibroblast pyroptosis and cardiac fibrosis.

Cardiac fibroblasts (CFs) drive extracellular matrix remodeling after inflammatory injury, leading to cardiac fibrosis and diastolic dysfunction. Recent studies described the role of epigenetics in cardiac fibrosis. Nevertheless, detailed reports on epigenetics regulating CFs pyroptosis and describing their implication in cardiac fibrosis are still unclear. Here, we found that DNMT3A reduces the expression of lncRNA Neat1 and promotes the NLRP3 axis leading to CFs pyroptosis, using cultured cells, animal models, and clinical samples to shed light on the underlying mechanism. We report that pyroptosis-related genes are increased explicitly in cardiac fibrosis tissue and LPS-treated CFs, while lncRNA Neat1 decreased. Mechanistically, we show that loss of DNMT3A or overexpression of lncRNA Neat1 in CFs after LPS treatment significantly enhances CFs pyroptosis and the production of pyroptosis-related markers in vitro. It has been demonstrated that DNMT3A can decrease lncRNA Neat1, promoting NLRP3 axis activation in CFs treated with LPS. In sum, this study is the first to identify that DNMT3A methylation decreases the expression of lncRNA Neat1 and promotes CFs pyroptosis and cardiac fibrosis, suggesting that DNMT3A and NEAT1 may function as an anti-fibrotic therapy target in cardiac fibrosis.

DNMT1-Induced miR-152-3p Suppression Facilitates Cardiac Fibroblast Activation in Cardiac Fibrosis.

Novel insights into epigenetic control of cardiac fibrosis are now emerging. Cardiac fibroblasts (CFs) activation into myofibroblasts and the production of extracellular matrix (ECM) is the key to cardiac fibrosis development, but the specific mechanism is not fully understood. In the present study, we found that DNMT1 hypermethylation reduces the expression of microRNA-152-3p (miR-152-3p) and promotes Wnt1/ß-catenin signaling pathway leading to CFs proliferation and activation. Cardiac fibrosis was produced by ISO, and the ISO was carried out according to the method described. CFs were harvested and cultured from SD neonatal rats and stimulated with TGF-ß1. Importantly, DNMT1 resulted in the inhibition of miR-152-3p in activated CFs and both DNMT1 and miR-152-3p altered Wnt/ß-catenin downstream protein levels. Over expression of DNMT1 and miR-152-3p inhibitors promotes proliferation of activating CFs. In addition, decreased methylation levels and over expression of miR-152-3p inhibited CFs proliferation. We determined that DNMT1 can methylate to miR-152-3p and demonstrated that expression of miR-152-3p inhibits CFs proliferation by inhibiting the Wnt1/ß-catenin pathway. Our results stand out together DNMT1 methylation regulates miR-152-3p to slow the progression of cardiac fibrosis by inhibiting the Wnt1/ß-catenin pathway.

MiR-21-3p triggers cardiac fibroblasts pyroptosis in diabetic cardiac fibrosis via inhibiting androgen receptor.

AIMS/HYPOTHESIS: MicroRNA-21 has been implicated in diabetic complication, including diabetic cardiomyopathy. However, there is limited information regarding the biological role of the miR-21 passenger strand (miR-21-3p) in diabetic cardiac fibrosis. The aim of this study was to investigate the role of miR-21-3p and its target androgen receptor in STZ-induced diabetic cardiac fibrosis. METHODS: The pathological changes and collagen depositions was analyzed by HE, Sirius Red staining and Masson's Trichrome Staining. MiR-21-3p, AR, NLRP3, caspase1 and collagen I expression were analyzed by western blotting, immunohistochemistry, immunofluorescence, qRT-PCR, miR one step qRT-PCR, respectively. A luciferase reporter assay was used to verify the interaction between miR-21 and the 3' untranslated region (3'UTR) of AR. RESULTS: Our results indicated that miR-21-3p level was up-regulated, while AR was decreased in STZ-induced diabetic cardiac fibrosis tissues and cardiac fibroblast. High glucose triggers cardiac fibroblasts pyroptosis and collagen deposition. Gain-of-function and loss-of-function assays demonstrated that miR-21-3p mediated the crucial role in diabetic cardiac fibrosis. Our results show that miR-21-3p bound to the 3'UTR of AR post-transcriptionally repressed its expression. We also found AR, which regulates cardiac fibroblasts pyroptosis and collagen deposition through caspase1 signaling. CONCLUSIONS: /interpretation: Taken together, our study showed that miR-21-3p aggravates STZ-induced diabetic cardiac fibrosis through the caspase1 pathways by suppressing AR expression.

DNMT1 Methylation of LncRNA GAS5 Leads to Cardiac Fibroblast Pyroptosis via Affecting NLRP3 Axis.

Cell death and inflammation play critical roles in cardiac fibrosis. During the fibrosis process, inflammation and tissue injury were triggered; however, the mechanisms initiating cardiac fibrosis and driving fibroblast pyroptosis remained largely unknown. In this study, we identified long non-coding RNA (LncRNA)-GAS5 as the key onset of cardiac fibroblast pyroptosis and cardiac fibrosis. Here, we detected ISO-induced cardiac fibrosis models and cardiac fibroblast pyroptosis model by stimulating with LPS. We found that the expression of pyroptosis-related proteins such as caspase 1, NLRP3, and DNMT1 was increased in cardiac fibrosis tissue, while the expression of GAS5 was decreased. The overexpressing of LncRNA GAS5 was shown to increase and inhibit cardiac fibroblast pyroptosis, as well as attenuate caspase 1 and NLRP3 expression in cardiac fibroblast. However, the silencing of GAS5 was also observed; it shows the opposite situation. Furthermore, further studies revealed that treatment of DNMT inhibitor, 5-aza-2-deoxycytidine, or downregulation of DNMT1 led to increased GAS5 expression by reversion of promoter hypermethylation in cardiac fibroblast. Importantly, we have demonstrated that DNMT1 methylation of LncRNA GAS5 leads to cardiac fibroblast pyroptosis via affecting NLRP3 axis. Our findings indicate a new regulatory mechanism for cardiac fibroblast pyroptosis under LPS stress, providing a novel therapeutic target for cardiac fibrosis. Graphical Abstract.

microRNA-29a inhibits cardiac fibrosis in Sprague-Dawley rats by downregulating the expression of DNMT3A.

OBJECTIVE: This study aims to investigate the effect of miR-29a targeting the regulation of DNMT3A on the development of cardiac fibrosis in Sprague-Dawley (SD) rats. METHODS: In vivo experiment: SD rats were randomly divided into model and control groups. The cardiac and left ventricular indices in each group were calculated. The pathological changes of the myocardium were observed. The expression levels of miR-29a, CollA1, α-SMA, and DNMT3A in the myocardium of each group were detected. In vitro experiment: The cardiac fibroblasts (CFs) of SD rats were isolated from the myocardial tissue of SD rats and cultured. The miR-29a mimics, inhibitors, DNMT3A-siRNA, and control-siRNA were transfected into CFs. The expression levels of miR-29a, DNMT3A, CollA1, and α-SMA were detected, and the proliferation of CFs after transfection was observed. RESULTS: The heart weight index of the rats in the model group increased significantly compared with that in the control group. Obvious collagen deposition was observed in the myocardial tissue of the model group. The expression levels of CollA1, α-SMA, and DNMT3A in the model group were significantly higher than those in the control group (p<0.05). CONCLUSION: miR-29a reduced the activation and proliferation of CFs to improve cardiac fibrosis probably by the downregulation of DNMT3A.

Epigenetic aberrations of miR-369-5p and DNMT3A control Patched1 signal pathway in cardiac fibrosis.

Modulation of epigenetic marks has promised efficacy for treating fibrosis. Cardiac fibroblast is the primary source of activated myofibroblasts that produce extracellular matrix (ECM) in cardiac fibrosis, but the mechanisms underlying this process are incompletely understood. Here we show that microRNA-369-5p (miR-369-5p) through DNMT3A hypermethylation and suppression of the Patched1 pathway leads to fibroblast proliferation in cardiac fibrosis. Forty adult male Sprague-Dawley (SD) rats were randomly divided into two groups (sham and AAC group), cardiac fibrosis was produced by abdominal aortic constriction, and the operation of abdominal aortic constriction was carried out according to the method described. Cardiac fibroblasts (CFs) were harvested from SD neonate rats and cultured. Importantly, miR-369-5p bind directly to DNMT3A with high affinity. MiR-369-5p leads to inhibition of DNMT3A enzyme activity. Exogenous miR-369-5p in cells induces aberrant DNA methylation of the Patched1, resulting in hypermethylation of low to moderately methylated regions. Moreover, Overexpression of miR-369-5p in cardiac fibroblast cells inhibits proliferation. We identify DNMT3A as miR-369-5p target genes and demonstrate that inhibition of miR-369-5p expression augments cell proliferation by activating DNMT3A and suppression of the Patched1 pathway. Together, our results highlight miR-369-5p mediated DNMT3A epigenetic silencing of Patched1 as a mechanism of fibroblast proliferation in cardiac fibrosis.

LncRNAs and miRs as epigenetic signatures in diabetic cardiac fibrosis: new advances and perspectives.

PURPOSE: Diabetic cardiomyopathy (DCM) is a serious cardiac complication of diabetes, which further lead to heartfailure. It is known that diabetes-induced cardiac fibrosis is a key pathogenic factor contributing topathological changes in DCM. However, pathogenetic mechanisms underlying diabetes cardiac fibrosis arestill elusive. Recent studies have indicated that noncoding RNAs (ncRNAs) play a key role in diabetescardiac fibrosis. The increasing complexity of epigenetic regulator poses great challenges to ourconventional conceptions regarding how ncRNAs regulate diabetes cardiac fibrosis. METHODS: We searched PubMed, Web of Science, and Scopus for manuscripts published prior to April 2018 using keywords "Diabetic cardiomyopathy" AND " diabetes cardiac fibrosis " OR " noncoding RNAs " OR " longnoncoding RNAs " OR " microRNAs " OR "epigenetic". Manuscripts were collated, studied and carriedforward for discussion where appropriate. RESULTS: Based on the view that during diabetic cardiac fibrosis, ncRNAs are able to regulate diabetic cardiac fibrosisby targeting genes involved in epigenetic pathways. Many studies have focused on ncRNAs, an epigeneticregulator deregulating protein-coding genes in diabetic cardiac fibrosis, to identify potential therapeutictargets. Recent advances and new perspectives have found that long noncoding RNAs and microRNAs,exert their own effects on the progression of diabetic cardiac fibrosis. CONCLUSION: We firstly examine the growing role of ncRNAs characteristics and ncRNAs-regulated genes involved indiabetic cardiac fibrosis. Then, we provide several possible therapeutic strategies and highlight the potentialof molecular mechanisms in which targeting epigenetic regulators are considered as an effective means of treating diabetic cardiac fibrosis.

DNMT3A controls miR-200b in cardiac fibroblast autophagy and cardiac fibrosis.

AIM AND OBJECTIVE: Regulation of microRNA gene expression by DNA methylation may represent a key mechanism to drive cardiac fibrosis progression. Cardiac fibroblast autophagy is the primary source of cardiac fibrosis, but the mechanisms underlying this process are incompletely understood. Here we found that DNMT3A suppression of the microRNA-200b (miR-200b) through pathway leads to cardiac fibroblast autophagy in cardiac fibrosis. METHODS: To understand the impact of DNMT3A on miR-200b at cardiac fibrosis, the rat cardiac fibrosis model was established via the abdominal aortic coarctation. Cardiac fibroblasts (CFs) were harvested from SD neonate rats and cultured. The expression of DNMT3A, miR-200b, collagen I was measured by western blotting, immunohistochemistry and qRT-PCR. Gain- or loss-of-function approaches were used to manipulate DNMT3A and miR-200b. RESULTS: DNMT3A level was upregulated and negatively correlated with miR-200b expression in fibrosis tissues and cardiac fibroblast. We found that autophagy was activated by miR-200b inhibitor and inactivated by miR-200b mimic in the rat cardiac fibroblast. Knockdown of DNMT3A notably increased the expression of miR-200b. CONCLUSIONS: Taken together, these findings indicate that DNMT3A regulation of miR-200b controls cardiac fibroblast autophagy during cardiac fibrosis and provide a basis for the development of therapies for cardiac fibrosis.

Epigenetic signatures in cardiac fibrosis, special emphasis on DNA methylation and histone modification.

Cardiac fibrosis is defined as excess deposition of extracellular matrix (ECM), resulting in tissue scarring and organ dysfunction. In recent years, despite the underlying mechanisms of cardiac fibrosis are still unknown, numerous studies suggest that epigenetic regulation of cardiac fibrosis. Cardiac fibrosis is regulated by a myriad of factors that converge on the transcription of genes encoding extracellular matrix protein, a process the epigenetic machinery plays a pivotal role. Epigenetic modifications contain three main processes: DNA methylation, histone modifications, and noncoding RNAs. Here, we review recent studies that have illustrated key roles for epigenetic events in the control of pro-fibrotic gene expression, and highlight the potential of molecule mechanisms that target epigenetic regulators as a means of treating cardiac fibrosis.

Development of a nanoliposomal formulation of erlotinib for lung cancer and in vitro/in vivo antitumoral evaluation.

The aim of this study was to develop PEGylation liposomes formulations of erlotinib and evaluate their characteristics, stability, and release characteristics. The average particle sizes and entrapment efficiency of PEGylation erlotinib liposomes are 102.4±3.1 nm and 85.3%±1.8%, respectively. Transmission electron microscopy images showed that the liposomes dispersed well with a uniform shape and no changes during the storage. The in vitro drug-release kinetic model of erlotinib release from the PEGylation liposomes in phosphate-buffered saline fit well with the Higuchi equation. In vitro anticancer activity assay showed that the blank liposomes had lower cellular cytotoxicity and that the cellular cytotoxicity of erlotinib liposomes increased significantly under the same incubation condition, which should contribute to the increase in intracellular drug concentration by the transportation of liposomes. The two liposomes of erlotinib (with and without PEGylation) exhibited similar cellular cytotoxicity with no significantly different concentrations. Pharmacokinetic results indicated that erlotinib-loaded PEGylation liposomes can significantly change the pharmacokinetic behavior of drugs and improve the drug bioavailability by nearly 2 times compared to ordinary liposomes. No sign of damages such as the appearance of epithelial necrosis or sloughing of epithelial cells was detected in histological studies.

MicroRNA-21 via Dysregulation of WW Domain-Containing Protein 1 Regulate Atrial Fibrosis in Atrial Fibrillation.

BACKGROUND: microRNAs (miRs) have been reported to regulate cell biological functions. To explore the underlying mechanism of miR-21 involvement in patients with atrial fibrosis and atrial fibrillation (AF). METHODS: In total, 49 patients (24 AF, sinus rhythm 25) aged 33-68 years old, including heart valve replacement surgery and cardiac catheterisation. The pathological changes and collagen depositions was analysed by Masson's Trichrome Staining. miR-21, TGF-ß1, Smad2, p-Smad2, WWP-1, collagen I and collagen III expression were analysed by Western blotting, qRT-PCR, miR one step qRT-PCR, respectively. Treatment human cardiac fibroblasts with TGF-ß1, qRT-PCR and Western blotting to find changes in miR-21, Smad2 and WWP-1 levels. Transfected human cardiac fibroblasts with miR-21 mimic and miR-21 inhibitor. Finally, cell proliferation ability was assessed by the MTT assay and flow cytometry. RESULTS: Compared to sinus rhythm (SR) group, the collagen volume fraction was significantly increased in AF patients. The levels of the TGF-ß1, collagen I and collagen III were significantly elevated in AF group. In AF patients, the expression of miR-21 was increased, while the expression of WWP-1 was decreased. Transfected cardiac fibroblasts with miR-21 mimic increased miR-21 expression and decreased WWP-1 expression, whereas miR-21 inhibitor causes the opposite effects. Additionally, we demonstrated that knockdown miR-21 targeted up-regulation of WWP-1 may suppress cardiac fibroblasts proliferation. CONCLUSION: These indicated that miR-21 inhibits cardiac fibroblasts proliferation by inactivating the TGF-ß1/Smad2 signaling pathway via up-regulation of WWP-1.

LncRNA GAS5 controls cardiac fibroblast activation and fibrosis by targeting miR-21 via PTEN/MMP-2 signaling pathway.

Long noncoding RNAs (LncRNAs) are aberrantly expressed in many diseases including cardiac fibrosis. LncRNA growth arrest-specific 5 (GAS5) is reported as a significant mediator in the control of cell proliferation and growth; however, the role and function in cardiac fibrosis remain unknown. In this study, we confirmed that GAS5 was lowly expressed in cardiac fibrosis tissues as well as activated cardiac fibroblast. Overexpression of GAS5 inhibited the proliferation of cardiac fibroblast. Moreover, microRNA-21 (miR-21) has been reported to be overexpressed in cardiac fibrosis tissues as well as activated cardiac fibroblast, which is responsible for the progression of cardiac fibrosis. We found that up-regulated GAS5 decreased the expression of miR-21 significantly. Furthermore, GAS5 that upregulated or downregulated the expression of PTEN through miR-21 in cardiac fibroblasts. Taken together, GAS5 plays a suppressive role in cardiac fibrosis via negative regulation of miR-21. These results indicated that GAS5 may be a novel therapeutic target for further research of cardiac fibrosis.

Lower Circulating Folate Induced by a Fidgetin Intronic Variant Is Associated With Reduced Congenital Heart Disease Susceptibility.

BACKGROUND: Folate deficiency is an independent risk factor for congenital heart disease (CHD); however, the maternal plasma folate level is paradoxically not a good diagnostic marker. Genome-wide surveys have identified variants of nonfolate metabolic genes associated with the plasma folate level, suggesting that these genetic polymorphisms are potential risk factors for CHD. METHODS: To examine the effects of folate concentration-related variations on CHD risk in the Han Chinese population, we performed 3 independent case-control studies including a total of 1489 patients with CHD and 1745 control subjects. The expression of the Fidgetin (FIGN) was detected in human cardiovascular and decidua tissue specimens with quantitative real-time polymerase chain reaction and Western blotting. The molecular mechanisms were investigated by luciferase reporter assays, surface plasmon resonance, and chromatin immunoprecipitation. FIGN-interacting proteins were confirmed by tandem affinity purification and coimmunoprecipitation. Proteasome activity and metabolite concentrations in the folate pathway were quantified with a commercial proteasome activity assay and immunoassays, respectively. RESULTS: The +94762G>C (rs2119289) variant in intron 4 of the FIGN gene was associated with significant reduction in CHD susceptibility (P=5.1×10-14 for the allele, P=8.5×10--13 for the genotype). Analysis of combined samples indicated that CHD risks in individuals carrying heterozygous (GC) or homozygous (CC) genotypes were reduced by 44% (odds ratio [OR]=0.56; 95% confidence interval [CI]=0.47-0.67) and 66% (OR=0.34; 95% CI=0.23-0.50), respectively, compared with those with the major GG genotype. Minor C allele carriers who had decreased plasma folate levels exhibited significantly increased FIGN expression because the transcription suppressor CREB1 did not bind the alternative promoter of FIGN isoform X3. Mechanistically, increased FIGN expression led to the accumulation of both reduced folate carrier 1 and dihydrofolate reductase via inhibition of their proteasomal degradation, which promoted folate absorption and metabolism. CONCLUSIONS: We report a previously undocumented finding that decreased circulating folate levels induced by increased folate transmembrane transport and utilization, as determined by the FIGN intronic variant, serves as a protective mechanism against CHD. Our results may explain why circulating folate levels do not have a good diagnostic value.

Long noncoding RNA H19 controls DUSP5/ERK1/2 axis in cardiac fibroblast proliferation and fibrosis.

Down-regulation of DUSP5 has been shown to increase cell proliferation. DUSP5 expression is regulated through epigenetic events involving LncRNA H19 human choriocarcinoma cell line. However, the molecular mechanisms of H19 modulating the DUSP5 expression in cardiac fibrosis remain largely unknown. Here, we identify H19 negatively regulation of DUSP5 gene expression in cardiac fibroblast and fibrosis tissues. In vivo, the expression levels of H19, DUSP5, α-SMA, p-ERK1/2, and ERK1/2 in cardiac fibrosis tissue were estimated by Western blotting, quantitative reverse transcription-polymerase chain reaction and immunohistochemistry. In vitro stimulation of freshly isolated rat cardiac fibroblasts with recombinant marine TGF-ß1 was performed, followed by quantitative reverse transcription-polymerase chain reaction and Western blotting to detect changes in H19, DUSP5, p-ERK1/2, and ERK1/2 levels. Cardiac fibroblasts were transfected with pEX-3-H19 overexpressing, H19-RNAi down-regulating, or pEGFP-C1-DUSP5 overexpressing. Finally, cell proliferation was assessed by the MTT assay and cell cycle. H19 endogenous expression is overexpressed in cardiac fibroblast and fibrosis tissues, and an opposite pattern is observed for DUSP5. H19 ectopic overexpression reduces DUSP5 abundance and increases the proliferation of cardiac fibroblast, whereas H19 silencing causes the opposite effects. In a broader perspective, these results demonstrated that LncRNA H19 contributes to cardiac fibroblast proliferation and fibrosis, which act in part through repression of DUSP5/ERK1/2.

MicroRNA-29a suppresses cardiac fibroblasts proliferation via targeting VEGF-A/MAPK signal pathway.

Cardiac fibroblasts proliferation is the most important pathophysiological character of cardiac fibrosis while the underlying mechanisms are still incompletely known. MicroRNAs (miRNAs) regulate gene expression by binding to specific sites. Studies have been indicated that miRNA-29a play a key role in cardiac fibrosis. VEGF-A carries out its functions through MAPK signaling pathway in cardiac fibrosis. Existing proofs predict that the VEGF-A is one of the potential targets of miRNA-29a. We therefore probe the role of miRNA-29a and its latent target VEGF-A during cardiac fibrosis. In our study, miRNA-29a was down-regulated while VEGF-A was up-regulated in cardiac fibrosis tissues. The rat cardiac fibroblasts that were transfected with miRNA-29a inhibitor exhibited low-expression of miRNA-29a, enhanced VEGF-A protein and mRNA expression. Nevertheless, the cardiac fibroblasts transfected with miRNA-29a mimics obtained the opposite expression result. Furthermore, over-expression of miRNA-29a suppresses cardiac fibroblasts proliferation. In conclusion, these results suggested that miRNA-29a suppresses cardiac fibrosis and fibroblasts proliferation via targeting VEGF-A/MAPK signal pathway implicating that miRNA-29a might play a role in the treatment of cardiac fibrosis.

Epigenetic factors MeCP2 and HDAC6 control α-tubulin acetylation in cardiac fibroblast proliferation and fibrosis.

AIM AND OBJECTIVE: Cardiac fibrosis is an important pathological feature of cardiac remodeling in heart diseases. Methyl-CpG-binding protein 2 (MeCP2) is a transcription inhibitor, and plays a key role in the fibrotic diseases. However, the precise role of MeCP2 in cardiac fibrosis remains unclear. α-tubulin plays an essential role in cell function, whereby the acetylation state of α-Tubulin dictates the efficiency of cell proliferation and differentiation. This study was undertaken to investigate that MeCP2 dynamics affect the acetylation state of α-tubulin in the cardiac fibrosis. METHODS: Forty adult male Sprague-Dawley (SD) rats were randomly divided into two groups, cardiac fibrosis was produced by common ISO. Cardiac fibroblasts (CFs) were harvested from SD neonate rats and cultured. The expression of HDAC6, MeCP2, α-SMA, collagen I was measured by western blotting and qRT-PCR. siRNA of HDAC6 and MeCP2 effect the proliferation of cardiac fibroblasts, and affect the acetylation state of α-tubulin. RESULTS: We have found the acetylation state of α-tubulin in cardiac fibroblasts as well as cardiac tissue from a ISO-induced rat cardiac fibrosis model and observed a reduction in acetylated α-tubulin and an increase in the α-tubulin-specific deacetylase, histone deacetylase 6 (HDAC6). Furthermore, we have shown that treatment of cardiac fibroblasts with HDAC6 inhibitor Tubastatin A and HDAC6-siRNA can restore α-tubulin acetylation levels. In addition, treatment of cardiac fibroblasts with MeCP2-siRNA blocked cell proliferation. Knockdown of MeCP2 suppresses HDAC6 expression in activated cardiac fibroblasts but increases the acetylation of α-tubulin. CONCLUSIONS: We demonstrated that MeCP2 may negatively control the acetylation of α-tubulin through HDAC6 in cardiac fibroblast proliferation and fibrosis. This study indicated that MeCP2 could be a potentially new therapeutic option for cardiac fibrosis.

Wnt signaling pathway in cardiac fibrosis: New insights and directions.

OBJECTIVE: Wnt signaling pathway significantly participates in cardiac fibrosis and CFs activation. Therefore, we reviewed current evidence on the new perspectives and biological association between Wnt signaling pathway and cardiac fibrosis. DESIGN AND METHODS: A PubMed database search was performed for studies of Wnt signaling pathway in cardiac fibrosis and CFs activation. RESULTS: Numerous studies have shown that the Wnt signaling pathway significantly participates in cardiac fibrosis pathogenesis. The aim of this review is to describe the present knowledge about the Wnt signaling pathway significantly participating in cardiac fibrosis and CFs activation, and look ahead on new perspectives of Wnt signaling pathway research. Moreover, we will discuss the different insights that interact with the Wnt signaling pathway-regulated cardiac fibrosis. The Wnt proteins are glycoproteins that bind to the Fz receptors on the cell surface, which lead to several important biological functions, such as cell differentiation and proliferation. There are several signals among the characterized pathways of cardiac fibrosis, including Wnt/ß-catenin signaling. In this review, new insight into the Wnt signaling pathway in cardiac fibrosis pathogenesis is discussed, with special emphasis on Wnt/ß-catenin. CONCLUSION: It seems reasonable to suggest the potential targets of Wnt signaling pathway and it can be developed as a therapeutic target for cardiac fibrosis.

Noncoding RNA as regulators of cardiac fibrosis: current insight and the road ahead.

Cardiac fibrosis is an important pathological feature of cardiac remodeling in heart diseases. The molecular mechanisms of cardiac fibrosis are unknown. Genomic analyses estimated that many noncoding DNA regions generate noncoding RNAs (ncRNAs). ncRNAs have emerged as key molecular players in the regulation of gene expression in different biological processes. Recent studies have started to reveal the importance of ncRNAs in heart development and suggest also an involvement in cardiac fibrosis. These molecules are emerging as important regulators of cellular process. Here, we review particularly focuses on the involvement of two large families of ncRNAs, namely microRNAs (miRNAs) and long noncoding RNAs (LncRNAs) in the regulation of cardiac fibrosis. Furthermore, we review the functions and role of ncRNAs in cardiac biology and discuss these reports and the therapeutic potential of ncRNAs for cardiac fibrosis associated with fibroblast activation and proliferation.

Emerging role of long noncoding RNAs in lung cancer: Current status and future prospects.

Lung cancer is the leading cause of cancer-related death worldwide with a 5-year survival rate of less than 15%, despite significant advances in both diagnostic and therapeutic approaches. Combined genomic and transcriptomic sequencing studies have identified numerous genetic driver mutations that are responsible for the development of lung cancer. Importantly, these approaches have also uncovered the widespread expression of "noncoding RNAs" including long noncoding RNAs (LncRNAs), which impact biologic responses through the regulation of mRNA transcription or translation. To date, most studies of the role of noncoding RNAs have focused on LncRNAs, which regulate mRNA translation via the RNA interference pathway. Although many of their attributes, such as patterns of expression, remain largely unknown, LncRNAs have key functions in transcriptional, post-transcriptional, and epigenetic gene regulation. Recent research showed that LncRNAs regulate flowering time in the lung cancer. In this review, we discuss these investigations into long noncoding RNAs were performed almost exclusively in lung cancer. Future work will need to extend these into lung cancer and to analyze how LncRNAs interact to regulate mRNA expression. From a clinical perspective, the targeting of LncRNAs as a novel therapeutic approach will require a deeper understanding of their function and mechanism of action.