Neural stem cell-derived exosomes suppress neuronal cell apoptosis by activating autophagy via miR-374-5p/STK-4 axis in spinal cord injury

Objectives:To evaluate the roles of MicroRNAs (miRNAs) enclosed in the neuron-derived exosomes in the recovery of the spinal cord injury (SCI) and the mechanism.Methods:The exosomes were isolated from neural stem cells (NSCs) and characterized by transmission electron microscopy (TEM) and NanoSight system (NTA). For in vivo experiments, Basso Mouse Scale, beam walking, and inclined plane tests were used to determine the behavioral symptoms of the SCI mice. For in vitro experiments, H₂O₂ treated HT22 cells were used to simulate SCI cells and cocultured with exosomes to analyze the cell apoptosis using TUNEL assays and flow cytometry. Apoptosis- and autophagy-related protein expression was detected by western blot and the green fluorescent protein (GFP)-LC3 assay was used to detect the level of autophagy. In addition, luciferase assay was performed to assess the relationship between miR-374-5p and SKT-4.Results:Exosomes from NSCs alleviated spinal cord injury by triggering autophagy flux and suppressing apoptosis. Besides, miR-374-5p was highly expressed in these exosomes and was responsible for the decent in injured neural cell apoptosis by activating autophagy flux. The SKT-4 was the target gene regulated by miR-374-5p in this exosomal protective function to SCI cells.Conclusion:The elevated level of miR-374-5p in neuronal exosomes could enhance spinal cord injury recovery by activating autophagy.     

MiR-296-5p ameliorates deep venous thrombosis by inactivating S100A4

Deep venous thrombosis is one of the most common venous thromboembolic diseases and has a low cure rate and a high postoperative recurrence rate. Furthermore, emerging evidence indicates that microRNAs are involved in deep venous thrombosis. miR-296-5p is an important microRNA that plays a critical role in various cellular functions, and S100A4 is closely related to vascular function. miR-296-5p is downregulated in deep venous thrombosis patients, and its predicted target S100A4 is upregulated in deep venous thrombosis patients. Therefore, it was hypothesized that miR-296-5p may play a vital role in the development of deep venous thrombosis by targeting S100A4. An Ox-LDL-stimulated HUVEC and deep venous thrombosis mouse model was employed to detect the biological functions of miR-296-5p and S100A4. Dual luciferase reporter assays and pull-down assays were used to authenticate the interaction between miR-296-5p and S100A4. ELISA and Western blotting were employed to detect the protein levels of thrombosis-related factors and the endothelial-to-mesenchymal transition (EndMT)-related factors. The miR-296-5p levels were reduced, while the S100A4 levels were enhanced in deep venous thrombosis patients, and the miR-296-5p levels were negatively correlated with the S100A4 levels in deep venous thrombosis patients. miR-296-5p suppressed S100A4 expression by targeting the 3ʹ UTR of S100A4. MiR-296-5p knockdown accelerated ox-LDL-induced HUVEC apoptosis, oxidative stress, thrombosis-related factor expression, and EndMT, while S100A4 knockdown antagonized these effects in ox-LDL-induced HUVECs. S100A4 knockdown reversed the effect induced by miR-296-5p knockdown. Moreover, the in vivo studies revealed that miR-296-5p knockdown in deep venous thrombosis mice exacerbated deep venous thrombosis formation, whereas S100A4 knockdown had the opposite effect. These results indicate that elevated miR-296-5p inhibits deep venous thrombosis formation by inhibiting S100A4 expression. Both miR-296-5p and S100A4 may be potential diagnostic markers and therapeutic targets for deep venous thrombosis.     

miR-140-5p suppresses BMP2-mediated osteogenesis in undifferentiated human mesenchymal stem cells

Human mesenchymal stem cells (hMSCs) have self-renewal and differentiation capabilities but the regulatory mechanisms of MSC fate determination remain poorly understood. Here, we aimed to identify microRNAs enriched in hMSCs that modulate differentiation commitments. Microarray analysis revealed that miR-140-5p is commonly enriched in undifferentiated hMSCs from various tissue sources. Moreover, bioinformatic analysis and luciferase reporter assay validated that miR-140-5p directly represses bone morphogenic protein 2 (BMP2). Furthermore, blocking miR-140-5p in hMSCs increased the expression of BMP signaling components and critical regulators of osteogenic differentiation. We propose that miR-140-5p functionally inhibits osteogenic lineage commitment in undifferentiated hMSCs.     

CircTIMELESS regulates the proliferation and invasion of lung squamous cell carcinoma cells via the miR-136-5p/ROCK1 axis

Numerous studies demonstrate that circular RNAs (circRNAs) are critical regulators of the occurrence and progression of tumors. However, research on the involvement of circRNAs in lung squamous cell carcinoma (LUSC) is limited. In our study, circTIMELESS (also named hsa_circ_0000408 in the Human circRNA Database) was upregulated in both LUSC tissues and LUSC cells, and circTIMELESS expression was positively associated with the TNM stage. Moreover, circTIMELESS silencing markedly suppressed invasion in vitro and disrupted proliferation in vitro as well as in vivo. Additional investigations have shown that circTIMELESS functions as a miR-136-5p “sponge” and regulates miR-136-5p expression. Furthermore, the impact of miR-136-5p upregulation was consistent with the results of circTIMELESS silencing, both of which inhibited the proliferation and invasion of LUSC cells. Additional results showed that Rho-associated coiled-coil containing protein kinase 1 (ROCK1) is targeted by miR-136-5p. The results of recovery experiments showed that ROCK1 overexpression partly rescued the impact of circTIMELESS silencing and miR-136-5p upregulation on proliferation and invasion. Consequently, our findings confirmed that circTIMELESS exists in LUSC and acts as a tumor promoter through the miR-136-5p/ROCK1 axis. Based on these findings, circTIMELESS may be potentially utilized as a therapeutic target for LUSC.     

miR-181a/b-5p regulates human umbilical vein endothelial cell angiogenesis by targeting PDGFRA

Type 2 diabetes mellitus (T2DM) is a growing burden in low-and middle-income countries. Changing lifestyles and lack of physical activity are some of the reasons contributing to this epidemic increase. Co-morbidities associated with T2DM are largely due to the complications which arise as a consequence of endothelial dysfunction. Platelet derived growth factor-alpha (PDGFRA) is a protein responsible for cell proliferation, angiogenesis, migration and invasion. Increased levels of PDGFRA have been reported in T2DM. This study assessed the epigenetic regulation of PDGFRA through microRNAs (miR-181a/b-5p).Using a bioinformatics-based approach, we assessed the binding of miR-181a/b-5p to PDGFRA. Experimentally, this binding was confirmed using a dual luciferase reporter assay. Further, we overexpressed miR-181a/b-5p in Human umbilical vein endothelial cells (HUVECs) and the influence of over-expression on cell proliferation, migration and angiogenesis was assessed using in-vitro approaches. The influence of miR-181a/b-5p over expression on cellular apoptosis was ascertained using a TUNEL assay with concomitant changes being observed in the levels of Bcl-2 and cleaved Caspase-3.In HUVECs, PDGFRA is a direct target for miR-181a/b-5p. Over expression of miR-181a/b-5p decreased cellular proliferation, migration, invasion, and tube formation—a surrogate marker for angiogenesis. miR-181a/b-5p may be used as a therapeutic intervention to restrict uncontrolled levels of PDGFRA and thereby rescue the phenotypes of increased cell proliferation, migration, invasion and tube formation. miR-181a/b negatively regulates PDGFRA levels. Significance of the study : T2DM and its associated complications emerge from endothelial dysfunction. The associated phenotypes are regulated by a number of proteins, one such member being, PDGFRA. PDGFRA is in turn regulated by miR-181a/b-5p. Complementation with miR-181a/b-5p resulted in reversion of phenotypes. Thus, miR-181a/b-5p-mediated suppression of PDGFRA may be used as a therapeutic intervention in the management of type 2 diabetes.     

miR-324-5p protects against oxidative stress-induced endothelial progenitor cell injury by targeting Mtfr1

Endothelial progenitor cells (EPCs) belong to bone marrow-derived myeloid progenitor cells that have strong proliferative ability. Dysregulation of miRNAs after acute myocardial infarction (AMI) can result in EPCs injury, thus we hypothesize that correction of miRNA expression may contribute to the tolerance of EPCs against oxidative stress. The peripheral blood of healthy volunteers and patients with ST-segment elevation myocardial infarction (STEMI) was clinically collected. EPCs derived from peripheral blood were transfected by miR-324-5p mimic and simultaneously handled with hydrogen peroxide (H₂O₂) to inducing EPCs injury. At 24 hrs after the H₂O₂ treatment, cell viability, the uptake capacity on DiI-Ac-LDL, and carrying ability on FITC-UEA-l and multiplication capacity were analyzed. The mechanism process was carefully researched by valued the characteristics of the mitochondrion morphology, membrane potential, ATP levels, and the expressing of apoptosis pathways. Small RNA sequencing indicated that the expression level of miR-324-5p in peripheral blood EPCs of patients with STEMI was significantly lower compared with the healthy volunteers. The Mtfr1 has been confirmed as a targeted gene of miR-324-5p through miRTarBase software and western blot. The miR-324-5p mimic units could be contributed for the improvement of viability, the uptake capacity on DiI-Ac-LDL and carrying ability on FITC-UEA-l and multiplication capacity on oxidative stress-injured EPCs. miR-324-5p could suppress mitochondrial fragmentation, promote membrane potential, and ATP levels, as well as protect against oxidative stress-induced EPCs apoptosis. Our results suggested that miR-324-5p protects against oxidative stress-induced EPCs injury by regulating Mtfr1.     

Long noncoding RNA PRKCQ-AS1 promotes CRC cell proliferation and migration via modulating miR-1287-5p/YBX1 axis

Colorectal cancer (CRC) brings more than 600 000 deaths every year around the globe, making itself the third most frequently occurred carcinoma. The great progress human achieved in diagnosis and treatment of various cancers has failed to reverse this trend. Fortunately, growing evidence has implied the relationship between lncRNAs and cancer progression. Long noncoding RNA (lncRNA) PRKCQ-AS1 was heightened in CRC cells and tissues and related with dismal prognosis of CRC patients. Knockdown of PRKCQ-AS1 would induce a decrease in proliferative and migrating ability of CRC cells. Also, PRKCQ-AS1 enriched in cytoplasm of CRC cells and negatively regulated miR-1287-5p level. More important, PRKCQ-AS1 could bind to argonaute 2 and function in the RNA-induced silencing complex with miR-1287-5p. Therefore, PRKCQ-AS1 was a competing endogenous RNA for miR-1287-5p. Subsequently, it was validated that miR-1287-5p could suppress the proliferative and migratory functions in CRC. Furthermore, PRKCQ-AS1 could upregulate the mRNA and protein level of YBX1 targeted by miR-1287-5p. And YBX1 expression was elevated in CRC cells and tissues. Rescue assays in vitro and in vivo showed that overexpression of YBX1 could partly offset the effect of CRC progression induced by knocking down PRKCQ-AS1, demonstrating PRKCQ-AS1 mediating CRC progression via miR-1287-5p/YBX1 pathway.     

Protective effect of miR-138-5p inhibition modified human mesenchymal stem cell on ovalbumin-induced allergic rhinitis and asthma syndrome

The objective of the study is to evaluate the protective effects of human mesenchymal stem cells (hMSCs) modified with miR-138-5p inhibitor against the allergic rhinitis and asthma syndrome (ARAS). MiR-138-5p or negative control was transfected into hMSCs, and fluorescence-activated cell sorting was used to evaluate hMSC surface markers. Quantitative real-time PCR (qRT-PCR) was used to evaluate miR-138-5p, SIRT1, caspase-3, IL-6, IL-1β and TNF-α levels after TNF-α and IL-6 stimulations. hMSCs with or without miR-138-5p inhibition was intranasally administered into ARAS mice (n = 10 each group), followed by monitoring sneezing and nasal rubbing events to evaluate the allergic symptoms. Histamine, ovalbumin-specific IgE, IgG2a, IgG1 and LTC4 release were monitored in the serum and nasal lavage fluid using enzyme-linked immunosorbent assay. Expression of SIRT1 and HMGB1/TLR4 pathway in nasal mucosa was assessed. After miR-138-5p inhibitor transfection, the hMSC lineage was preserved. Binding between SIRT1 and miR-138-4p was observed, and miR-138-5p inhibition led to upregulation of SIRT1. Inhibition of miR-138-5p led to attenuated inflammatory responses of hMSCs upon TNF-α and IL-6 stimulation, and allergic symptoms in mice, as well as histamine and ovalbumin-specific IgG release. hMSCs with miR-138-5p inhibition showed characteristics of activated SIRT1 and inhibited HMGB1/TLR4 pathway. Inhibition of miR-138-5p in hMSCs enhanced its effects in attenuating inflammatory responses and allergic reaction in the ARAS model, which is presumably regulated by SIRT1 and the HMGB1/TLR4 pathway.     

miR-205-5p in exosomes divided from chondrogenic mesenchymal stem cells alleviated rheumatoid arthritis via regulating MDM2 in fibroblast-like synoviocytes

Objective:To explore the role and mechanism of chondrogenic bone marrow mesenchymal stem cells (BMSCs)-derived exosomes on Rheumatoid arthritis (RA).Methods:The chondrogenesis of BMSCs was induced by chondrogenic medium. Exosomes from BMSCs and chondrogenic BMSCs were isolated and characterized by transmission electron microscope (TEM), laser particle size analyzer and western blot. ELISA was used to analyze the expression levels of pro-inflammatory cytokines and matrix metalloproteinases (MMPs). Western bolt was performed to assess MAPK and NF-κB pathways expression. The inflammation score and the pathological damage of RA mice were evaluated. Luciferase reporter assay and RIP were carried out to examine the relationship between microRNA-205-5p (miR-205-5p) and mouse double minute 2 (MDM2).Results:Chondrogenic BMSCs-derived exosomes suppressed pro-inflammatory cytokines, MMPs and MAPK and NF-κB pathways in RA-FLSs. miR-205-5p had a high expression in chondrogenic BMSCs-derived exosomes. Functionally, exosomal miR-205-5p also played the anti-inflammation effects. Besides, MDM2 was a direct target of miR-205-5p. Additionally, chondrogenic BMSCs-secreted exosomal miR-205-5p suppressed the inflammation score, joint destruction, and inflammatory response in collagen-induced arthritis (CIA) mice through MDM2.Conclusion:Chondrogenic BMSCs-derived exosomal miR-205-5p suppressed inflammatory response, MAPK and NF-κB pathways through MDM2 in RA, indicating exosomal miR-205-5p might be a potential target for RA treatment.     

Silencing of circ_0000205 mitigates interleukin-1β-induced apoptosis and extracellular matrix degradation in chondrocytes via targeting miR-766-3p/ADAMTS5 axis

The aim of this study was to explore the role of hsa_circRNA_0000205 (circ_0000205) in chondrocyte injury in osteoarthritis (OA) and the underlying mechanism. Expression of circ_0000205, microRNA (miR)-766-3p and a disintegrin and metalloproteinase with thrombospondin motif (ADAMTS)-5 was detected by quantitative real time (qRT)-polymerase chain reaction (PCR) and Western blot assays. Cell proliferation, apoptosis, and extracellular matrix (ECM) synthesis were examined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and 5-ethynyl-2-deoxyuridine assays, flow cytometry, and qRT-PCR and Western blot assays. The target relationship between miR-766-3p and circ_0000205 or ADAMTS5 was confirmed by luciferase reporter assay and RNA immunoprecipitation. IL-1β treatment could attenuate cell viability of primary chondrocytes and proliferating cell nuclear antigen (PCNA) and collagen II type alpha-1 (COL2A1) levels, and elevate apoptosis rate and cleaved caspase-3, ADAMTS5 and matrix metalloproteinase-13 (MMP13) levels, suggesting that IL-1β induced chondrocyte apoptosis and ECM degradation. Expression of circ_0000205 was up-regulated in OA tissues and IL-1β-induced primary chondrocytes, accompanied with miR-766-3p down-regulation and ADAMTS5 up-regulation. Knockdown of circ_0000205 could mitigate IL-1β-induced above effects and improve cell proliferation. Moreover, both depleting miR-766-3p and promoting ADAMTS5 could partially counteract circ_0000205 knockdown roles in IL-1β-cultured primary chondrocytes. Notably, circ_0000205 was verified as a sponge for miR-766-3p via targeting, and ADAMTS5 was a direct target for miR-766-3p. Silencing circ_0000205 could protect chondrocytes from IL-1β-induced proliferation reduction, apoptosis, and ECM degradation by targeting miR-766-3p/ADAMTS5 axis.     

miR-155-5p regulates mesenchymal stem cell osteogenesis and proliferation by targeting GSK3B in steroid-associated osteonecrosis

microRNAs (miRNAs) have recently been recognized as playing an important role in bone-associated diseases. This study investigated whether the reduced miR-155-5p in steroid-associated osteonecrosis of the femoral head (ONFH) attenuated osteogenic differentiation and cell proliferation by targeting GSK3B. Bone marrow was collected from the proximal femurs of patients with steroid-associated ONFH (n = 10) and patients with new femoral neck fracture (n = 10) and mesenchymal stem cells (MSCs) were isolated. The expression profile, the biological function of miR-155-5p, and the interaction between miR-155-5p and GSK3B were investigated by cell viability measurement, western blot, real-time polymerase chain reaction, luciferase reporter assay, and Alizarin Red S (ARS) staining of MSCs. The MSCs that were obtained from the femoral neck fracture group and from the steroid-associated ONFH group were transfected with or without miR-155-5p. We found that, in ONFH samples, the level of mature miR-155-5p was significantly lower than that of control samples. By inhibiting GSK3B, miR-155-5p promoted the nuclear translocation of β-catenin, increased the expression of osteogenesis-related genes, and facilitated the proliferation and differentiation of MSCs. Restoring the expression of GSK3B in MSCs partially reversed the effect of miR-155-5p. These findings suggest that reduced miR-155-5p in steroid-associated ONFH attenuates osteogenic differentiation and cell proliferation by increased levels of GSK3B and inhibition of Wnt signaling.     

Linc-ROR regulates apoptosis in esophageal squamous cell carcinoma via modulation of p53 ubiquitination by targeting miR-204-5p/MDM2

The long intergenic noncoding RNA, regulator of reprogramming (linc-ROR) has been reported to participate in tumorigenesis, while its functions and fundamental mechanisms in esophageal squamous cell carcinoma (ESCC) remain unclear. In this study, gain-of-function assays showed that linc-ROR upregulation enhanced cell viability, promoted cell proliferation, and inhibited apoptosis. Mechanistically, the regulatory network of linc-ROR/miR-204-5p/MDM2 was established with bioinformatics analysis and online databases, then validated via dual-luciferase reporter assays, RNA immunoprecipitation assays in ESCC cells. Linc-ROR positively regulates the expression of MDM2 as a molecular sponge of miR-204-5p. Moreover, results of western blot and coimmunoprecipitation indicated that linc-ROR overexpression enhanced the ubiquitination level of p53, and its downstream apoptosis-related genes have showed higher bcl-2 expression, lower bax, and cleaved caspase-3 expressions, while miR-204-5p could counteract with this effect. Finally, small interfering RNAs tailored to linc-ROR were established to further evaluate its effects on ESCC comprehensively. In summary, this study revealed that linc-ROR modulated cell apoptosis and regulated p53 ubiquitination via targeting miR-204-5p/MDM2 axis, which provides a novel therapeutic insight into treatments for ESCC.     

miR-214-5p targets KLF5 and suppresses proliferation of human hepatocellular carcinoma cells

MicroRNAs (miRNAs) are small endogenous conserved RNAs regulating genes expression through base pairing with the 3′-untranslated region (3′-UTR) of target messenger RNAs. MiR-214-5p is a newly identified miRNA with its biological role largely unknown. In this study, we explored miR-214-5p expression status in 78 paired tumor and nontumor tissues obtained from patients with hepatocellular carcinoma (HCC) by RT-qPCR. The effects of miR-214-5p expression on HCC cell proliferation, cell cycle progression, and cell migration were measured by CCK-8 assay, flow cytometry, and wound-healing assay. A dual-luciferase activity assay was performed to identify whether KLF5 was a target of miR-214-5p. Kaplan-Meier curve and log-rank test were used to investigate the effects of miR-214-5p and KLF5 on overall survival and disease-free survival of patients with HCC. We found miR-214-5p expression was sharply reduced in HCC tissues and cell lines compared with the normal tissues and cell lines. Functional assay revealed that miR-214-5p overexpression could downregulate cell proliferation, cell migration, and arrested cell cycle at G0/G1 phase. Further, we validated Krüppel-like factor 5 (KLF5) as a direct target of miR-214-5p, and was upregulated in HCC and inversely correlated with the expression of miR-214-5p. Moreover, we found the low expression of miR-214-5p and high expression of KLF5 were correlated with tumor size, tumor stage, and poorer 5-year overall survival and disease-free survival of patients with HCC. In conclusion, our results suggested miR-214-5p functions as a tumor suppressor through targeting KLF5 in HCC. Also, miR-214-5p and KLF5 were identified as potential prognostic markers and might be therapeutic targets in HCC.