miR-142-5p and miR-212-5p cooperatively inhibit the proliferation and collagen formation of cardiac fibroblasts by regulating c-Myc/TP53INP1

Dihydromyricetin Protects Against Hypoxia/Reoxygenation Injury in Cardiomyocytes by Activating miR-34a-Mediated Notch1 Pathway

Dihydromyricetin (Dih), a naturally occurring flavonoid, has been identified to exert a protective effect against ischemia/reperfusion injury. However, the detailed mechanisms remain unclear. Here we investigated the biological role of Dih in preventing hypoxia/reoxygenation (H/R) injury in cardiomyocytes. The results showed that Dih protected cardiomyocytes against H/R-induced apoptosis, as proved by improved cell viability and decreased lactate dehydrogenase (LDH) release, cell apoptosis percentage, and caspase-3/7 activity. H/R-induced oxidative stress in cardiomyocytes was also prevented by Dih with increased activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT), and decreased levels of malondialdehyde (MDA) and reactive oxygen species (ROS). Treatment with Dih prevented H/R-induced increase in the activities of myocardial enzymes aspartate aminotransferase (AST), creatine kinase-MB (CK-MB), and creatine kinase (CK). miR-34a expression was upregulated after H/R stimulation, which could be attenuated by Dih pretreatment. Besides, miR-34a overexpression attenuated the protective effects of Dih against H/R-caused increase in apoptosis, oxidative stress, and myocardial enzyme activities. Next, we demonstrated that Notch1 was a target molecule of miR-34a. Notch1 overexpression reversed the role of miR-34a in regulating the cardioprotective effect of Dih on H/R injury. These observations indicated that the cardioprotective effect of Dih against H/R injury was mediated by the miR-34a/Notch1 signaling. Dih may be a candidate agent for improving the clinical efficacy of cardiac ischemia/reperfusion injury treatment.

Single-cell analysis reveals the loss of FABP4-positive proliferating valvular endothelial cells relates to functional mitral regurgitation

BACKGROUND

Functional mitral regurgitation (MR) is a common form of mitral valve dysfunction that often persists even after surgical intervention, requiring reoperation in some cases. To advance our understanding of the pathogenesis of functional MR, it is crucial to characterize the cellular composition of the mitral valve leaflet and identify molecular changes in each cell subtype within the mitral valves of MR patients. Therefore, we aimed to comprehensively examine the cellular and molecular components of mitral valves in patients with MR.

METHODS

We conducted a single-cell RNA sequencing (scRNA-seq) analysis of mitral valve leaflets extracted from six patients who underwent heart transplantation. The cohort comprised three individuals with moderate-to-severe functional MR (MR group) and three non-diseased controls (NC group). Bioinformatics was applied to identify cell types, delineate cell functions, and explore cellular developmental trajectories and interactions. Key findings from the scRNA-seq analysis were validated using pathological staining to visualize key markers in the mitral valve leaflets. Additionally, in vitro experiments with human primary valvular endothelial cells were conducted to further support our results.

RESULTS

Our study revealed that valve interstitial cells are critical for adaptive valve remodelling, as they secrete extracellular matrix proteins and promote fibrosis. We discovered an abnormal decrease in a subpopulation of FABP4 (fatty acid binding protein 4)-positive proliferating valvular endothelial cells. The trajectory analysis identifies this subcluster as the origin of VECs. Immunohistochemistry on the expanded cohort showed a reduction of FABP4-positive VECs in patients with functional MR. Intervention experiments with primary cells indicated that FABP4 promotes proliferation and migration in mitral valve VECs and enhances TGFβ-induced differentiation.

CONCLUSIONS

Our study presented a comprehensive assessment of the mitral valve cellular landscape of patients with MR and sheds light on the molecular changes occurring in human mitral valves during functional MR. We found a notable reduction in the proliferating endothelial cell subpopulation of valve leaflets, and FABP4 was identified as one of their markers. Therefore, FABP4 positive VECs served as proliferating endothelial cells relates to functional mitral regurgitation. These VECs exhibited high proliferative and differentiative properties. Their reduction was associated with the occurrence of functional MR.

Novel Peptide DR3penA as a Low-Toxicity Antirenal Fibrosis Agent by Suppressing the TGF-β1/miR-212-5p/Low-Density Lipoprotein Receptor Class a Domain Containing 4/Smad Axis

Renal fibrosis is a complex pathological process that contributes to the development of chronic kidney disease due to various risk factors. Conservative treatment to curb progression without dialysis or renal transplantation is widely applicable, but its effectiveness is limited. Here, the inhibitory effect of the novel peptide DR3penA (DHα-(4-pentenyl)-AlaNPQIR-NH2), which was developed by our group, on renal fibrosis was assessed in cells and mice with established fibrosis and fibrosis triggered by transforming growth factor-β1 (TGF-β1), unilateral ureteral obstruction, and repeated low-dose cisplatin. DR3penA preserved renal function and ameliorated renal fibrosis at a dose approximately 100 times lower than that of captopril, which is currently used in the clinic. DR3penA also significantly reduced existing fibrosis and showed similar efficacy after subcutaneous or intraperitoneal injection. Mechanistically, DR3penA repressed TGF-β1 signaling via miR-212-5p targeting of low-density lipoprotein receptor class a domain containing 4, which interacts with Smad2/3. In addition to having good pharmacological effects, DR3penA could preferentially target injured kidneys and exhibited low toxicity in acute and chronic toxicity experiments. These results unveil the advantages of DR3penA regarding efficacy and toxicity, making it a potential candidate compound for renal fibrosis therapy.

Association of circulating hsa-miRNAs with sarcopenia: the SarcoPhAge study

OBJECTIVE

To identify a microRNA signature associated to sarcopenia in community-dwelling older adults form the SarcoPhAge cohort.

METHODS

In a screening phase by next generation sequencing (NGS), we compared the hsa-miRome expression of 18 subjects with sarcopenia (79.6 ± 6.8 years, 9 men) and 19 healthy subjects without sarcopenia (77.1 ± 6 years, 9 men) at baseline. Thereafter, we have selected eight candidate hsa-miRNAs according to the NGS results and after a critical assessment of previous literature. In a validation phase and by real-time qPCR, we then analyzed the expression levels of these 8 hsa-miRNAs at baseline selecting 92 healthy subjects (74.2 ± 10 years) and 92 subjects with sarcopenia (75.3 ± 6.8 years). For both steps, the groups were matched for age and sex.

RESULTS

In the validation phase, serum has-miRNA-133a-3p and has-miRNA-200a-3p were significantly decreased in the group with sarcopenia vs controls [RQ: relative quantification; median (interquartile range)]: -0.16 (-1.26/+0.90) vs +0.34 (-0.73/+1.33) (p < 0.01) and -0.26 (-1.07/+0.68) vs +0.27 (-0.55/+1.10) (p < 0.01) respectively. Has-miRNA-744-5p was decreased and has-miRNA-151a-3p was increased in the group with sarcopenia vs controls, but this barely reached significance: +0.16 (-1.34/+0.79) vs +0.44 (-0.31/+1.00) (p = 0.050) and  +0.35 (-0.22/+0.90) vs  +0.03 (-0.68/+0.75) (p = 0.054).

CONCLUSION

In subjects with sarcopenia, serum hsa-miRNA-133a-3p and hsa-miRNA-200a-3p expression were downregulated, consistent with their potential targets inhibiting muscle cells proliferation and differentiation.

Epigenetic signatures in cardiac fibrosis: Focusing on noncoding RNA regulators as the gatekeepers of cardiac fibroblast identity

Cardiac fibroblasts play a pivotal role in cardiac fibrosis by transformation of fibroblasts into myofibroblasts, which synthesis and secrete a large number of extracellular matrix proteins. Ultimately, this will lead to cardiac wall stiffness and impaired cardiac performance. The epigenetic regulation and fate reprogramming of cardiac fibroblasts has been advanced considerably in recent decades. Non coding RNAs (microRNAs, lncRNAs, circRNAs) regulate the functions and behaviors of cardiac fibroblasts, including proliferation, migration, phenotypic transformation, inflammation, pyroptosis, apoptosis, autophagy, which can provide the basis for novel targeted therapeutic treatments that abrogate activation and inflammation of cardiac fibroblasts, induce different death pathways in cardiac fibroblasts, or make it sensitive to established pathogenic cells targeted cytotoxic agents and biotherapy. This review summarizes our current knowledge in this field of ncRNAs function in epigenetic regulation and fate determination of cardiac fibroblasts as well as the details of signaling pathways contribute to cardiac fibrosis. Moreover, we will comment on the emerging landscape of lncRNAs and circRNAs function in regulating signal transduction pathways, gene translation processes and post-translational regulation of gene expression in cardiac fibroblast. In the end, the prospect of cardiac fibroblasts targeted therapy for cardiac fibrosis based on ncRNAs is discussed.

Circulating miRNAs Expression in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a complex multifactorial disease that causes increasing morbidity worldwide, and many individuals with ME/CFS symptoms remain undiagnosed due to the lack of diagnostic biomarkers. Its etiology is still unknown, but increasing evidence supports a role of herpesviruses (including HHV-6A and HHV-6B) as potential triggers. Interestingly, the infection by these viruses has been reported to impact the expression of microRNAs (miRNAs), short non-coding RNA sequences which have been suggested to be epigenetic factors modulating ME/CFS pathogenic mechanisms. Notably, the presence of circulating miRNAs in plasma has raised the possibility to use them as valuable biomarkers for distinguishing ME/CFS patients from healthy controls. Thus, this study aimed at determining the role of eight miRNAs, which were selected for their previous association with ME/CFS, as potential circulating biomarkers of the disease. Their presence was quantitatively evaluated in plasma from 40 ME/CFS patients and 20 healthy controls by specific Taqman assays, and the results showed that six out of the eight of the selected miRNAs were differently expressed in patients compared to controls; more specifically, five miRNAs were significantly upregulated (miR-127-3p, miR-142-5p, miR-143-3p, miR-150-5p, and miR-448), and one was downmodulated (miR-140-5p). MiRNA levels directly correlated with disease severity, whereas no significant correlations were observed with the plasma levels of seven pro-inflammatory cytokines or with the presence/load of HHV-6A/6B genome, as judged by specific PCR amplification. The results may open the way for further validation of miRNAs as new potential biomarkers in ME/CFS and increase the knowledge of the complex pathways involved in the ME/CFS development.

miR-8485 alleviates the injury of cardiomyocytes through TP53INP1

MicroRNAs (miRNAs) feature prominently in regulating the progression of chronic heart failure (CHF). This study was performed to investigate the role of miR-8485 in the injury of cardiomyocytes and CHF. It was found that miR-8485 level was markedly reduced in the plasma of CHF patients, compared with the healthy controls. H₂ O₂ treatment increased tumor necrosis factor-α, interleukin (IL)-6, and IL-1β levels, inhibited the viability of human adult ventricular cardiomyocyte cell line AC16, and increased the apoptosis, while miR-8485 overexpression reversed these effects. Tumor protein p53 inducible nuclear protein 1 (TP53INP1) was identified as a downstream target of miR-8485, and TP53INP1 overexpression weakened the effects of miR-8485 on cell viability, apoptosis, as well as inflammatory responses. Our data suggest that miR-8485 attenuates the injury of cardiomyocytes by targeting TP53INP1, suggesting it is a protective factor against CHF.

Smartly responsive DNA-miRNA hybrids packaged in exosomes for synergistic enhancement of cancer cell apoptosis

Endogenous and exogenous tumor-related microRNAs (miRNAs) are considered promising tumor biomarkers and tumor therapeutic agents. In this work, we propose a miRNA self-responsive drug delivery system (miR-SR DDS), which enables the association between endogenous and exogenous miRNAs, so as to achieve a smart responsive and synergistic drug delivery. The miR-SR DDS consists of DNA-miRNA hybrids of let-7a and the complementary DNA of miR-155, which was packaged in exosomes. In response to the overexpressed miR-155 in breast cancer cells, the hybrids disintegrate and release let-7a and the complementary DNA of miR-155 to inhibit the expression of HMGA1 and relieve the inhibition of SOX1, respectively. Under the dual-targeted gene regulation, results show that the growth, migration and invasion of breast cancer cells can be synergistically inhibited through the Wnt/β-catenin signaling pathway. The concept and successful practice of the miR-SR DDS can be used as a reference for the development of miRNA drugs.

Inhibition of GARS1-DT Protects Against Hypoxic Injury in H9C2 Cardiomyocytes via Sponging miR-212-5p

ABSTRACT

The present study aimed to elucidate the function of long noncoding RNA GARS1-DT in hypoxia-induced injury in ex-vivo cardiomyocytes and explore its underlying mechanism. Hypoxic injury was confirmed in H9C2 cells by the determination of cell viability, migration, invasion, and apoptosis. GARS1-DT expression was estimated in H9C2 cells after hypoxia. We then measured the effects of GARS1-DT knockdown on hypoxia-induced H9C2 cells. The interaction between GARS1-DT and miR-212-5p was also investigated. Hypoxia treatment led to cell damage in H9C2 cardiomyocytes, accompanied with the upregulation of GARS1-DT expression. Transfection of GARS1-DT small interfering RNA remarkably attenuated hypoxia-induced injury by enhancing cell viability, migration, and invasion, and reducing apoptosis. Furthermore, GARS1-DT served as an endogenous sponge for miR-212-5p, and its expression was negatively regulated by GARS1-DT. The effects of GARS1-DT knockdown on hypoxia-induced injury were significantly abrogated by miR-212-5p silence. Besides, suppression of GARS1-DT activated PI3K/AKT pathway in hypoxia-treated H9C2 cells, which were reversed by inhibition of miR-212-5p. Our findings demonstrated the novel molecular mechanism of GARS1-DT/miR-212-5p/PI3K/AKT axis on the regulation of hypoxia-induced myocardial injury in H9C2 cells, which may provide potential therapeutic targets for acute myocardial infarction treatment.

MSCs-Derived Extracellular Vesicles Carrying miR-212-5p Alleviate Myocardial Infarction-Induced Cardiac Fibrosis via NLRC5/VEGF/TGF-β1/SMAD Axis

The purpose of the present study was to define the role of mesenchymal stem cell (MSC)-derived extracellular vesicles (EVs) in the progression of myocardial infarction (MI)-induced cardiac fibrosis. An in vitro cell model of hypoxia-induced cardiac fibrosis was constructed in cardiac fibroblasts (CFs). miR-212-5p was poorly expressed in clinical pathological samples and animal models of cardiac fibrosis caused by MI, while miR-212-5p expression was enriched in EVs released from MSCs. EVs from MSCs were isolated, evaluated, and co-cultured with CFs. Dual-luciferase reporter gene assay revealed that miR-212-5p negatively targeted NLRC5 progression of cardiac fibrosis. Following loss- and gain-function assay, EVs expressing miR-212-5p protected against cardiac fibrosis evidenced by reduced levels of α-SMA, Collagen I, TGF-β1, and IL-1β. In vivo experiments further confirmed the above research results. Collectively, EVs from MSCs expressing miR-212-5p may attenuate MI by suppressing the NLRC5/VEGF/TGF-β1/SMAD axis.

Long Noncoding RNA Small Nuclear RNA Host Gene 7 Knockdown Protects Mouse Cardiac Fibroblasts Against Myocardial Infarction by Regulating miR-455-3p/Platelet-Activating Factor Receptor Axis

ABSTRACT

Myocardial infarction (MI) is a leading cause of heart failure all over the world. Long noncoding RNAs have been reported to be associated with the development of MI. In this article, we aimed to explore the effects of long noncoding RNA small nuclear RNA host gene 7 (SNHG7) on MI and the possible mechanism. In this study, an MI model was established by ligating the left anterior descending coronary artery of mice. Cardiac fibroblasts (CFs) derived from neonatal mice were activated by angiotensin II (Ang-II) treatment. The expression of SNHG7 and miR-455-3p was examined by quantitative real-time polymerase chain reaction, and protein levels of platelet-activating factor receptor (PTAFR) and fibrosis-related proteins were analyzed by western blot assay. Cell apoptosis of CFs was monitored by flow cytometry. Enzyme-linked immunosorbent assay was performed to evaluate inflammatory responses in CFs. Moreover, dual-luciferase reporter assay was used to confirm the target relationship between miR-455-3p and SNHG7 or PTAFR. LncRNA SNHG7 and PTAFR were upregulated, whereas miR-455-3p was downregulated in cardiac tissues of mice with MI and Ang-II-induced CFs. SNHG7 depletion or miR-455-3p overexpression attenuated Ang-II-induced apoptosis, fibrosis, and inflammation in CFs, which was severally weakened by miR-455-3p inhibition or PTAFR upregulation. LncRNA SNHG7 targeted miR-455-3p, and PTAFR was a target of miR-455-3p. LncRNA SNHG7 depletion exerted protective roles in apoptosis, fibrosis, and inflammation in Ang-II-induced CFs by regulating miR-455-3p/PTAFR axis, providing a potential molecular target for MI therapy.

Neuroprotective effect of miR-212-5p on isoflurane-induced cognitive dysfunction by inhibiting neuroinflammation

BACKGROUND

Isoflurane is a commonly used inhalation anesthetic in the clinic, which can induce cognitive dysfunction and neuroinflammation. miR-212-5p has been demonstrated to be involved in the neuronal system and play vital roles in memory formation. Its function in the learning and memory impairment and neuroinflammation induced by isoflurane was investigated in this study.

METHODS

Cognitive dysfunction rat models were established by 3% isoflurane inhalation. The neurological function was evaluated by the modified Neurological Severity Scale. The learning and memory ability of rats was assessed by the Morris water maze test. The expression level of miR-212-5p was analyzed by RT-qPCR, and the protein levels of proinflammatory cytokines were detected by ELISA.

RESULTS

Isoflurane induced cognitive dysfunction in rats with the neurological scores and the escape latency increased, and time spent in the target quadrant decreased. The protein levels of IL-1β, IL-6, and TNF-α were increased in isoflurane treated rats. miR-212-5p was downregulated in cognitive impairment rats. The upregulation of miR-212-5p by the agomir injection decreased the neurological scores of rats and increased the learning and memory ability of impaired rats. Moreover, the neuroinflammation was inhibited by the overexpression of miR-212-5p.

CONCLUSION

miR-212-5p showed a neuroprotective effect in isoflurane-induced cognitive dysfunction rats by inhibiting neuroinflammation.