MiR-26a-5p Targets WNT5A to Protect Cardiomyocytes from Injury Due to Hypoxia/Reoxygenation Through the Wnt/β-catenin Signaling Pathway

Dental Pulp Stem Cells Attenuate Early Brain Injury After Subarachnoid Hemorrhage via miR-26a-5p/PTEN/AKT Pathway

Subarachnoid hemorrhage (SAH) is a type of hemorrhagic stroke with high morbidity, mortality and disability, and early brain injury (EBI) after SAH is crucial for prognosis. Recently, stem cell therapy has garnered significant attention in the treatment of neurological diseases. Compared to other stem cells, dental pulp stem cells (DPSCs) possess several advantages, including abundant sources, absence of ethical concerns, non-invasive procurement, non-tumorigenic history and neuroprotective potential. Therefore, we aim to investigate whether DPSCs can improve EBI after SAH, and explore the mechanisms. In our study, we utilized the endovascular perforation method to establish a SAH mouse model and investigated whether DPSCs administered via tail vein injection could improve EBI after SAH. Furthermore, we used hemin-stimulated HT22 cells to simulate neuronal cell injury induced by SAH and employed a co-culture approach to examine the effects of DPSCs on these cells. To gain insights into the potential mechanisms underlying the improvement of SAH-induced EBI by DPSCs, we conducted bioinformatics analysis. Finally, we further validated our findings through experiments. In vivo experiments, we found that DPSCs administration improved neurological dysfunction, reduced brain edema, and prevented neuronal apoptosis in SAH mice. Additionally, we observed a decrease in the expression level of miR-26a-5p in the cortical tissues of SAH mice, which was significantly increased following intravenous injection of DPSCs. Through bioinformatic analysis and luciferase reporter assay, we confirmed the target relationship between miR-26a-5p and PTEN. Moreover, we demonstrated that DPSCs exerted neuroprotective effects by modulating the miR-26a-5p/PTEN/AKT pathway. Our study demonstrates that DPSCs can improve EBI after SAH through the miR-26a-5p/PTEN/AKT pathway, laying a foundation for the application of DPSCs in SAH treatment. These findings provide a theoretical basis for further investigating the therapeutic mechanisms of DPSCs and developing novel treatment strategies in SAH.

Innovative Therapeutic Strategies for Myocardial Infarction Across Various Stages: Non-Coding RNA and Stem Cells

Myocardial infarction (MI) is a highly challenging and fatal disease, with diverse challenges arising at different stages of its progression. As such, non-coding RNAs (ncRNAs), which can broadly regulate cell fate, and stem cells with multi-differentiation potential are emerging as novel therapeutic approaches for treating MI across its various stages. NcRNAs, including microRNAs (miRNAs) and long non-coding RNAs (LncRNAs), can directly participate in regulating intracellular signaling pathways, influence cardiac angiogenesis, and promote the repair of infarcted myocardium. Currently, stem cells commonly used in medicine, such as mesenchymal stem cells (MSCs) and induced pluripotent stem cells (iPSCs), can differentiate into various human cell types without ethical concerns. When combined with ncRNAs, these stem cells can more effectively induce directed differentiation, promote angiogenesis in the infarcted heart, and replenish normal cardiac cells. Additionally, stem cell-derived exosomes, which contain various ncRNAs, can improve myocardial damage in the infarcted region through paracrine mechanisms. However, our understanding of the specific roles and mechanisms of ncRNAs, stem cells, and exosomes secreted by stem cells during different stages of MI remains limited. Therefore, this review systematically categorizes the different stages of MI, aiming to summarize the direct regulatory effects of ncRNAs on an infarcted myocardium at different points of disease progression. Moreover, it explores the specific roles and mechanisms of stem cell therapy and exosome therapy in this complex pathological evolution process. The objective of this review was to provide novel insights into therapeutic strategies for different stages of MI and open new research directions for the application of stem cells and ncRNAs in the field of MI repair.

Qingre Huoxue Decoction Alleviates Atherosclerosis by Regulating Macrophage Polarization Through Exosomal miR-26a-5p

Background

Qingre Huoxue Decoction (QRHX) is a classical Chinese herbal prescription widely used in clinical practice for the treatment of atherosclerosis (AS). Our previous study demonstrated its efficacy in stabilizing plaque and improving prognosis, as well as its ability to regulate macrophage polarization. This study aimed to further investigate the effects of QRHX on AS and explore the underlying mechanisms.

Methods

ApoE-/- mice were fed a high-fat diet (HFD) for 8 weeks in order to establish an AS model. Oil Red O, H&E, Masson, and IHC staining were employed to assess lipid accumulation, plaque development, collagen loss and target of the aortas tissue. ELISA was employed to measure the levels of TNF-α and IL-10 in serum. Dual luciferase reporter assay was conducted to ascertain the connection between miR-26a-5p and PTGS2 in vitro. Western blot and RT-qPCR assay were conducted to assess the NF-κB signaling pathway and macrophage polarization. The effects of miR-26a-5p were tested after transfecting miR-26a-5p over-expressive lentivirus.

Results

QRHX attenuated HFD-induced plaque progression and inflammation of AS model mice. BMDM-derived exosomes (BMDM-exo) increased miR-26a-5p and decreased PTGS2 expressions, inhibited the NF-κB signaling pathway and regulated macrophage polarization in vivo. These effects of BMDM-exo were further enhanced after QRHX intervention. Dual luciferase reporter assay results showed that miR-26a-5p directly binds to the 3'-UTR of PTGS2 mRNA and regulates the expression of PTGS2. The miR-26a-5p of BMDM-exo played a key role in macrophage polarization. After overexpression of miR-26a-5p, the NF-κB signaling pathway was inhibited and macrophages were converted from M1 to M2 in vitro.

Conclusion

QRHX can exert anti-inflammatory and plaque-stabilizing effects through exosomal miR-26a-5p via inhibiting the PTGS2/NF-κB signaling pathway and regulating macrophage phenotype from M1 to M2 polarization in AS.

Integrated MicroRNA-mRNA Analyses of the Osteogenic Differentiation of Human Dental Pulp Stem Cells by a Helioxanthin Derivative

Dental pulp stem cells (DPSCs) demonstrate high proliferative and multilineage differentiation potential. As previously reported, the helioxanthin derivative 4-(4-methoxyphenyl)pyrido[40,30:4,5]thieno[2,3-b]pyridine-2-carboxamide (TH) has been demonstrated to induce the osteogenic differentiation of DPSCs. However, the mechanism of osteogenesis induced by TH in DPSCs remains unknown. The objective of this study was to identify functional extracellular vesicle (EV) microRNAs (miRNAs), and the principal genes involved in the TH-induced osteogenesis of DPSCs. DPSCs were derived from dental pulp extracted from the third molars of three healthy subjects, and were cultured with or without TH. miRNAs were extracted from DPSC-derived EVs. The gene expression patterns of mRNA and miRNA were compared using RNA-Seq and miRNA-Seq. To investigate miRNA/mRNA interacting networks, functional analyses were performed by Ingenuity Pathway Analysis. Alkaline phosphatase (ALP) staining demonstrated that treatment with TH resulted in enhanced ALP activity in DPSCs after 7 days. The expression levels of ALP and type 1 collagen alpha 1 were significantly higher in TH-induced DPSCs on day 7. RNA-Seq and miRNA-Seq analyses identified 869 differentially expressed genes (DEGs) and 18 miRNA-DEGs. Gene Ontology analysis of the mRNA-Seq results showed that TH induced several biological activities associated with signal transduction, cell adhesion, and cell differentiation. Integrated miRNA-mRNA analyses showed that these miRNAs contain the targeting information of 277 mRNAs of the DEGs. Among them, 17 target genes known to be involved in the differentiation of osteoblasts, and 24 target genes known to be involved in the differentiation of bone cells were identified. Quantitative real-time PCR showed that WNT5a expression in DPSCs was upregulated by 48 h of TH treatment. Upstream regulator analysis indicated that WNT3a, FOS, and RAC1 may be responsible for gene expression changes in DPSCs after TH treatment. EV miRNA regulatory networks might play crucial roles in TH-induced osteogenic differentiation of DPSCs. Our results presented herein offer valuable insights that will facilitate further research into the mechanism of osteogenesis of DPSCs, which is expected to lead to the clinical application of TH-induced DPSCs for bone regeneration. Furthermore, EVs derived from TH-induced DPSCs might be useful as therapeutic tools for bone defects.

Knockdown of long noncoding RNA MIAT attenuates hypoxia-induced cardiomyocyte injury by regulating the miR-488-3p/Wnt/β-catenin pathway

Dysfunction of cardiomyocytes contributes to the development of acute myocardial infarction (AMI). Nonetheless, the regulatory mechanism of lncRNA myocardial infarction-associated transcript (MIAT) in cardiomyocyte injury remains largely unclear. The cardiomyocyte injury was assessed via cell viability and apoptosis using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) and flow cytometry, respectively. The levels of MIAT, microRNA (miR)-488-3p, and Wnt5a were detected via quantitative real-time polymerase chain reaction and Western blot. After bioinformatical analysis, the binding between miR-488-3p and MIAT or Wnt5a was confirmed via dual-luciferase reporter, RNA immunoprecipitation, and RNA pull-down assays. Our results showed that MIAT expression was increased in AC16 cells after hypoxia treatment. Silencing of MIAT alleviated hypoxia-induced viability reduction, apoptosis increase, and Wnt/β-catenin pathway activation. MIAT directly targeted miR-488-3p. MiR-488-3p might repress hypoxia-induced cardiomyocyte injury, and its knockdown reversed the effect of MIAT depletion on cardiomyocyte injury. Wnt5a was validated as a target of miR-488-3p. Wnt5a expression restoration attenuated the influence of MIAT knockdown on hypoxia-triggered cardiomyocyte injury. Our findings demonstrated that downregulation of MIAT might mitigate hypoxia-induced cardiomyocyte injury partly through miR-488-3p mediated Wnt/β-catenin pathway.

Dexmedetomidine protects H9C2 rat cardiomyocytes against hypoxia/reoxygenation injury by regulating the long non-coding RNA colon cancer-associated transcript 1/microRNA-8063/Wnt/β-catenin axis

Dexmedetomidine (Dex) protects the heart from ischemia/reperfusion (I/R) injury. The differential expression of long non-coding RNAs (lncRNAs) is associated with myocardial injury, but whether the lncRNA colon cancer-associated transcript 1 (CCAT1) is associated with Dex-mediated myocardial protection remains unclear. In this study, a hypoxia/reoxygenation (H/R) H9C2 model was established to simulate the in vitro characteristics of I/R. CCAT1 and microRNA (miR)-8063 expression levels in H/R H9C2 cells pretreated with Dex were determined via quantitative reverse transcription-polymerase chain reaction. The survival and apoptotic rates of H9C2 cells were determined via cell counting kit-8 and flow cytometry assays. Wnt3a, Wnt5a, and β-catenin protein levels were measured via western blotting. Luciferase and RNA immunoprecipitation assays were used to explore the binding relationship between miR-8063 and CCAT1. Dex pretreatment increased H/R H9C2 cell viability and CCAT1 expression, while decreasing the cell apoptosis and Wnt3a, Wnt5a, and β-catenin protein levels. Knockdown of CCAT1 abolished the protective effects of Dex on H/R H9C2 cells, and the downregulation of miR-8063 expression eliminated the effect of CCAT1 knockdown. These results revealed that CCAT1, a sponge for miR-8063, is involved in Dex-mediated H9C2 cell H/R injury by negatively targeting miR-8063 and inactivating the Wnt/β-catenin pathway. Dex protects H9C2 cells from H/R impairment by regulating the lncRNA CCAT1/miR-8063/Wnt/β-catenin axis.