TGF-β1 regulating miR-205/miR-195 expression affects the TGF-β signal pathway by respectively targeting SMAD2/SMAD7

Inhibition of miR-195-3p protects against cardiac dysfunction and fibrosis after myocardial infarction

Cardiac fibrosis following myocardial infarction is a major risk factor for heart failure. Recent evidence suggests that miR-195-3p is up-regulated in fibrotic diseases, including kidney and liver fibrosis. However, its function and underlying mechanisms in cardiac fibrosis after MI remain unknown. To investigate the role of miR-195-3p in MI-induced cardiac fibrosis, we established acute MI models by ligating adult C57B/L6 mice LAD coronary artery while sham-operated mice were used as controls. In vivo inhibition of miR-195-3p was conducted by intramyocardial injection of AAV9-anti-miR-195-3p. In vitro overexpression and inhibition of miR-195-3p were performed by transfecting cultured Cardiac Fibroblasts (CFs) with synthetic miRNA mimic and inhibitor. Our results showed that MI induced the expression of miR-195-3p and that inhibition of miR-195-3p reduced myofibroblast differentiation and collagen deposition and protected cardiac function. In vitro stimulation of CFs with TGF-β1 resulted in a significant increase in miR-195-3p expression. Inhibition of miR-195-3p attenuated the TGF-β1-induced expression of ECM proteins, migration, and proliferation. PTEN expression was significantly reduced in the hearts of MI mice, in activated CFs, and in CFs transfected with miR-195-3p mimic. Inhibition of miR-195-3p markedly restored PTEN expression in MI mice and TGF-β1-treated CFs. In conclusion, this study highlights the crucial role of miR-195-3p in promoting cardiac fibrosis and dysfunction after MI. Inhibiting miR-195-3p could be a promising therapeutic strategy for preventing cardiac fibrosis and preserving cardiac function after MI. Additionally, the study sheds light on the mechanisms underlying the effects of miR-195-3p on fibrosis, including its regulation of PTEN/AKT pathway.

Expression of Long Noncoding RNA, HOTAIR, and MicroRNA-205 and Their Relation to Transforming Growth Factor β1 in Patients with Alopecia Areata

Introduction

Alopecia areata (AA) is a common autoimmune condition that affects anagen hair follicles. The most commonly recognized theory is that it is a T-cell-mediated autoimmune disorder in a genetically susceptible individual. MicroRNAs (miRNAs) and long noncoding RNAs (lncRNAs) were thought to play a function in the pathogenesis. The expression of lncRNA HOTAIR and miRNA-205 and their relation to transforming growth factor β1 (TGF-β1) in AA were not studied.

Aim

The aim of the studywas to evaluate the role of miRNA-205, lncRNA, HOTAIR, and TGF-β1 levels in AA pathogenesis, clinical course, and severity of AA.

Methods

Two groups of subjects were included in this case-control study: 50 patients with AA and 50 healthy matched controls. miRNA-205 and lncRNA HOTAIR expression levels were assayed using quantitative RT-PCR, while serum levels of TGF-β1 were assayed using ELISA techniques.

Results

The serum expression of lncRNA HOTAIR was significantly downregulated in AA patients with a p value < 0.001, while the serum expression of both miRNA-205 and TGF-β1 were significantly upregulated in patients.

Discussion/Conclusion

This study highlights the potential role of high serum expression of miRNA-205 and TGF-β1 and the low serum expression of lncRNA HOTAIR in AA pathogenesis. This could be used as a therapeutic target to treat AA.

The Effect and the Mechanism of miR-209 Targeted Regulating PI3K (Phosphatidylinositol3-Kinase)/AKT (Protein Kinase B)/FOXO3a (Forkhead box O3) Signaling Pathway on Glioma Stem Cells

To explore the role and mechanism of miR-209 target regulating PI3K/Akt/FOXO3a in glioma. GSCs were isolated from the lesions of glioma patients, cultured, passaged and characterized. Set blank control group (with saline solution), miR-209-mimics group (cells transfected with miR-209-mimics) and negative control group (cells transfected with meaningless sequences). After cell transfection, observe the transfection efficiency of miR-209 MIC, detect the miR-209 mRNA expression level and biological peptide ions such as proliferation, migration, invasion, and withering, and detect the expression of PI3K/Akt/FOXO3a-related proteins (PI3K, p-Akt, FOXO3a). The miR-209mRNA expression level in the miR-209 mimics group was much higher (P < 0.01), and they two had indifferent differentiation (P >0.05); 24, 48 and 72 hours after transfection, the cell migration, proliferation rate and invasion ability of the miR-209 mimics group were much stronger (P <0.05) and the cell apoptosis rate at 24, 48, and 72 hours after transfection was much less (P < 0.01) and they two had no scientific differences (P > 0.05). The PI3K and p-Akt protein expression in the glioma stem elements of the miR-209 transfected group was much higher (P <0.01). The expression of FOXO3a was much less (P <0.01), while the standard level of PI3K, P-Akt and FOXO3a protein had no obvious difference (P >0.05). miR-209 can activate PI3K/Akt/FOXO3a to promote the growth, reproduction and invasion of GSCs, and control the cells withering system. This will provide new avenues for clinical trials.

Biological implications and clinical potential of invasion and migration related miRNAs in glioma

Gliomas are the most common primary malignant brain tumors and are highly aggressive. Invasion and migration are the main causes of poor prognosis and treatment resistance in gliomas. As migration and invasion occur, patient survival and prognosis decline dramatically. MicroRNAs (miRNAs) are small, non-coding 21–23 nucleotides involved in regulating the malignant phenotype of gliomas, including migration and invasion. Numerous studies have demonstrated the mechanism and function of some miRNAs in glioma migration and invasion. However, the biological and clinical significance (including diagnosis, prognosis, and targeted therapy) of glioma migration and invasion-related miRNAs have not been systematically discussed. This paper reviews the progress of miRNAs-mediated migration and invasion studies in glioma and discusses the clinical value of migration and invasion-related miRNAs as potential biomarkers or targeted therapies for glioma. In addition, these findings are expected to translate into future directions and challenges for clinical applications. Although many biomarkers and their biological roles in glioma invasion and migration have been identified, none have been specific so far, and further exploration of clinical treatment is still in progress; therefore, we aimed to further identify specific markers that may guide clinical treatment and improve the quality of patient survival.

Construction of the miRNA-mRNA Regulatory Networks and Explore Their Role in the Development of Lung Squamous Cell Carcinoma

Purpose: MicroRNA (miRNA) binds to target mRNA and inhibit post-transcriptional gene expression. It plays an essential role in regulating gene expression, cell cycle, and biological development. This study aims to identify potential miRNA-mRNA regulatory networks that contribute to the pathogenesis of lung squamous cell carcinoma (LUSC).

Patients and Methods: MiRNA microarray and RNA-Seq datasets were obtained from the gene expression omnibus (GEO) databases, the cancer genome atlas (TCGA), miRcancer, and dbDEMC. The GEO2R tool, “limma” and “DEseq” R packages were used to perform differential expression analysis. Gene enrichment analysis was conducted using the DAVID, DIANA, and Hiplot tools. The miRNA-mRNA regulatory networks were screened from the experimentally validated miRNA-target interactions databases (miRTarBase and TarBase). External validation was carried out in 30 pairs of LUSC tissues by Real-Time Quantitative Reverse Transcription PCR (qRT-PCR). Receiver operating characteristic curve (ROC) and decision curve analysis (DCA) were conducted to evaluate the diagnostic value. Clinical, survival and phenotypic analysis of miRNA-mRNA regulatory networks were further explored.

Results: We screened 5 miRNA and 10 mRNA expression datasets from GEO and identified 7 DE-miRNAs and 270 DE-mRNAs. After databases screening and correlation analysis, four pairs of miRNA-mRNA regulatory networks were screened out. The miRNA-mRNA network of miR-205-5p (up) and PTPRM (down) was validated in 30 pairs of LUSC tissues. MiR-205-5p and PTPRM have good diagnostic efficacy and are expressed differently in different clinical features and are related to tumor immunity.

Conclusion: The research identified a potential miRNA-mRNA regulatory network, providing a new way to explore the genesis and development of LUSC.

The Protective Effect of Picroside II on Isoflurane-Induced Neuronal Injury in Rats via Downregulating miR-195

INTRODUCTION

Numerous pieces of evidence demonstrated that isoflurane induces hippocampal cell injury and cognitive impairments. Picroside II has been investigated for its anti-apoptosis and antioxidant neuroprotective effects. We aimed to explore the protective effects of picroside II and the role of microRNA-195 (miR-195) on isoflurane-induced neuronal injury in rats.

METHODS

The Morris water maze test was used to evaluate the effects of isoflurane on rats regarding escape latency and time in quadrant parameters. Real-time quantitative PCR was used to detect the expression levels of miR-195 and pro-inflammatory cytokines, including inter-leukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) mRNA, in the hippocampal tissues and neuronal cells.

RESULTS

The picroside II significantly improves isoflurane-induced higher escape latency and lower time spent in the quadrant compared with the control rats. Picroside II also promotes cell viability and suppresses cell apoptosis of isoflurane-induced neuronal cells. Besides, picroside II suppresses the expression of pro-inflammatory cytokines (IL-1β, IL-6, and TNF-α) and miR-195 in vivo and in vitro. Furthermore, overexpression of miR-195 abrogates the effects of picroside II on the expression of pro-inflammatory cytokines. The appropriate dose of picroside II is 20 mg/kg.

CONCLUSION

Picroside II could protect the nervous system possibly through inhibiting the inflammatory response in the isoflurane-induced neuronal injury of rats. The protective effect of picroside II may be achieved by downregulating the expression of miR-195 and then inhibiting the inflammatory response.

Transcription factor Sp2 promotes TGFB-mediated interstitial cell osteogenic differentiation in bicuspid aortic valves through a SMAD-dependent pathway

Calcification of the bicuspid aortic valve (BAV) involves differential expression of various RNA genes, which is achieved through complex regulatory networks that are controlled in part by transcription factors and microRNAs. We previously found that miR-195-5p regulates the osteogenic differentiation of valvular interstitial cells (VICs) by targeting the TGF-β pathway. However, the transcriptional regulation of miR-195-5p in calcified BAV patients is not yet clear. In this study, stenotic aortic valve tissues from patients with BAVs and tricuspid aortic valves (TAVs) were collected. Candidate transcription factors of miR-195-5p were predicted by bioinformatics analysis and tested in diseased valves and in male porcine VICs. SP2 gene expression and the corresponding protein levels in BAV were significantly lower than those in TAV, and a low SP2 expression level environment in VICs resulted in remarkable increases in RNA expression levels of RUNX2, BMP2, collagen 1, MMP2, and MMP9 and the corresponding proteins. ChIP assays revealed that SP2 directly bound to the transcription promoter region of miR-195-5p. Cotransfection of SP2 shRNA and a miR-195-5p mimic in porcine VICs demonstrated that SP2 repressed SMAD7 expression via miR-195-5p, while knockdown of SP2 increased the mRNA expression of SMAD7 and the corresponding protein and attenuated Smad 2/3 expression. Immunofluorescence staining of diseased valves confirmed that the functional proteins of osteogenesis differentiation, including RUNX2, BMP2, collagen 1, and osteocalcin, were overexpressed in BAVs. In Conclusion, the transcription factor Sp2 is expressed at low levels in VICs from BAV patients, which has a negative impact on miR-195-5p expression by binding its promoter region and partially promotes calcification through a SMAD-dependent pathway.

P53/miR-154 Pathway Regulates the Epithelial-Mesenchymal Transition in Glioblastoma Multiforme Cells by Targeting TCF12

PURPOSE

Glioblastoma multiforme (GBM) is an aggressive brain tumor with a rather short survival time. Mutation of p53 has been observed and reported to play critical roles in the progression of GBM. However, the pathological mechanisms are still unclear. This study was designed to identify the role of miR-154 in mediating the biological functions of p53 in glioblastoma multiforme.

METHODS

In the current study, the expression of miR-154 in GBM tissue samples and cell lines with wt-p53 or mutant p53 was evaluated. The functions of miR-154 in tumor migration, invasion and epithelial-mesenchymal transition were analyzed in vitro. A luciferase reporter assay was used to identify the target of miR-154.

RESULTS

We found that expression of miR-154 was much lower in patient tissues with mutant p53. Further study revealed that p53 was a transcription factor of miR-154 and that the R273H mutation led to its inactivation. In addition, overexpression of miR-154 remarkably suppressed cell migration, invasion and EMT in vitro and tumor growth in vivo. Moreover, TCF12 was proven to be a direct target of miR-154, and the tumor suppressive effect of miR-154 was reversed by TCF12.

CONCLUSION

Overall, miR-154, which was regulated by wt-p53, inhibited migration, invasion and EMT of GBM cells by targeting TCF12, indicating that miR-154 may act as a biomarker and that the p53/miR-154/TCF12 pathway could be a potential therapeutic target for GBM.

Unveiling the ups and downs of miR-205 in physiology and cancer: transcriptional and post-transcriptional mechanisms

miR-205 plays important roles in the physiology of epithelia by regulating a variety of pathways that govern differentiation and morphogenesis. Its aberrant expression is frequently found in human cancers, where it was reported to act either as tumor-suppressor or oncogene depending on the specific tumor context and target genes. miR-205 expression and function in different cell types or processes are the result of the complex balance among transcription, processing and stability of the microRNA. In this review, we summarize the principal mechanisms that regulate miR-205 expression at the transcriptional and post-transcriptional level, with particular focus on the transcriptional relationship with its host gene. Elucidating the mechanisms and factors regulating miR-205 expression in different biological contexts represents a fundamental step for a better understanding of the contribution of such pivotal microRNA to epithelial cell function in physiology and disease, and for the development of modulation strategies for future application in cancer therapy.

MicroRNAs in diabetic nephropathy: From molecular mechanisms to new therapeutic targets of treatment

Despite considerable investigation in diabetic nephropathy (DN) pathogenesis and possible treatments, current therapies still do not provide competent prevention from disease progression to end-stage renal disease (ESRD) in most patients. Therefore, investigating exact molecular mechanisms and important mediators underlying DN may help design better therapeutic approaches for proper treatment. MicroRNAs (MiRNAs) are a class of small non-coding RNAs that play a crucial role in post-transcriptional regulation of many gene expression within the cells and present an excellent opportunity for new therapeutic approaches because their profile is often changed during many diseases, including DN. This review discusses the most important signaling pathways involved in DN and changes in miRNAs profile in each signaling pathway. We also suggest possible approaches for miRNA derived interventions for designing better treatment of DN.

LncRNA DGCR5 plays a tumor-suppressive role in glioma via the miR-21/Smad7 and miR-23a/PTEN axes

Glioma is one of the most commonly diagnosed brain malignancies with a high cancer-related death rate in humans. The prognosis of glioma patients is still unsatisfactory. In the present study, we attempted to identify lncRNAs and miRNAs that might be related to NF-κB-mediated epithelial-mesenchymal transition in glioma cells based on online microarray expression profiles, and investigate the specific effects of lncRNA-miRNA-mRNA axes on glioma cell phenotypes. Herein, we identified lncRNA DGCR5 as a downregulated lncRNA in glioma that was negatively regulated by NF-κB1 in an NF-κB1 RE-dependent manner. LncRNA DGCR5 overexpression significantly inhibited the capacity of glioma cells to proliferate, migrate, and invade, whereas promoted the apoptosis of glioma cells. Moreover, lncRNA DGCR5 overexpression upregulated the epithelial marker E-cadherin while downregulating the mesenchymal marker VIM, as well as Snai2 and TWIST. Regarding the underlying molecular mechanisms, lncRNA DGCR5 could inhibit miR-21 and miR-23a expression, and miR-21 or miR-23a overexpression significantly reversed the tumor-suppressive effects of lncRNA DGCR5 overexpression. LncRNA DGCR5 exerted its tumor-suppressive effects through the DGCR5/miR-21/Smad7 and DGCR5/miR-23a/PTEN axes. In conclusion, lncRNA DGCR5 suppresses the capacity of glioma cells to migrate and invade via miR-21/Smad7, whereas it inhibits the proliferation and enhances the apoptosis of glioma cells through miR-23a/PTEN.

Current perspectives on inhibitory SMAD7 in health and disease

Transforming growth factor β (TGF-β) family members play an extensive role in cellular communication that orchestrates both early development and adult tissue homeostasis. Aberrant TGF-β family signaling is associated with a pathological outcome in numerous diseases, and in-depth understanding of molecular and cellular processes could result in therapeutic benefit for patients. Canonical TGF-β signaling is mediated by receptor-regulated SMADs (R-SMADs), a single co-mediator SMAD (Co-SMAD), and inhibitory SMADs (I-SMADs). SMAD7, one of the I-SMADs, is an essential negative regulator of the pleiotropic TGF-β and bone morphogenetic protein (BMP) signaling pathways. In a negative feedback loop, SMAD7 inhibits TGF-β signaling by providing competition for TGF-β type-1 receptor (TβRI), blocking phosphorylation and activation of SMAD2. Moreover, SMAD7 recruits E3 ubiquitin SMURF ligases to the type I receptor to promote ubiquitin-mediated proteasomal degradation. In addition to its role in TGF-β and BMP signaling, SMAD7 is regulated by and implicated in a variety of other signaling pathways and functions as a mediator of crosstalk. This review is focused on SMAD7, its function in TGF-β and BMP signaling, and its role as a downstream integrator and crosstalk mediator. This crucial signaling molecule is tightly regulated by various mechanisms. We provide an overview of the ways by which SMAD7 is regulated, including noncoding RNAs (ncRNAs) and post-translational modifications (PTMs). Finally, we discuss its role in diseases, such as cancer, fibrosis, and inflammatory bowel disease (IBD).

Comprehensive analysis of a long non-coding RNA-associated competing endogenous RNA network in glioma

Long non-coding RNAs (lncRNAs) can act as competing endogenous RNAs (ceRNAs), interacting with microRNAs (miRNAs) and playing an important role in tumor progression. However, the role of lncRNA-mediated ceRNAs in glioma remains largely unknown. The present study aimed to identify novel lncRNAs and their associated function in glioma. RNA sequencing and corresponding clinical data from patients with glioma were obtained from The Cancer Genome Atlas. A total of 598 glioma tissues and 5 normal brain tissues were analyzed in the present study. The differentially expressed (DE) lncRNAs, mRNAs and miRNAs were identified using R packages and were used to construct a ceRNA network. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses were performed to investigate the biological functions of the DEmRNAs. Kaplan-Meier curve analysis was performed to investigate the association between DElncRNA expression and patient outcome. A total of 752 DElncRNAs, 2,079 DEmRNAs and 113 DEmiRNAs were identified between glioma and normal tissues. A lncRNA-miRNA-mRNA ceRNA network consisting of 61 lncRNAs, 12 miRNAs and 92 mRNAs was constructed. Survival analysis indicated that 36 DElncRNAs, 72 DEmRNAs and 3 DEmiRNAs were associated with overall survival in patients with glioma. The present study identified novel lncRNAs associated with survival prognosis and may facilitate further investigation of lncRNA-mediated ceRNA regulatory mechanisms in glioma.

Copper-Induced Upregulation of MicroRNAs Directs the Suppression of Endothelial LRP1 in Alzheimer's Disease Model

Chronic exposure to copper and its dyshomeostasis have been linked to accelerated cognitive decline and potentially increasing risk for Alzheimer's disease (AD). We and others have previously demonstrated that exposure to copper through drinking water significantly increased parenchymal amyloid-beta (Aβ) plaques and decreased endothelial low-density lipoprotein receptor-related protein 1 (LRP1) in mouse models of AD. In this study, we determined the underlying mechanisms that microRNA critically mediated the copper-induced loss of endothelial LRP1. In human primary microvascular endothelial cells (MVECs), microRNA-200b-3p, -200c-3p, and -205-5p were significantly elevated within the 24-h exposure to copper and returned to baseline after 48-h postexposure, which corresponded with the temporal change of LRP1 expression in these cells. Transient expression of synthetic microRNA-200b-3p, -200c-3p, or -205-5p on MVECs significantly decreased endothelial LRP1, and cotreatment of synthetic antagomirs effectively prevented the loss of LRP1 during copper exposure, collectively supporting the key regulatory role of these microRNAs in copper-induced loss of LRP1. In mice, a significant reduction of LRP1 in cortical vasculature was evident following 9 months exposure to 1.3 ppm copper in drinking water, although the levels of cortical microRNA-205-5p, -200b-3p, and -200c-3p were only marginally elevated. This, however, correlated with increased vascular accumulation of Aβ and impairment of spatial memory, indicating that copper exposure has the pivotal role in the vascular damage and development of cognitive decline.

MiR-195 and miR-497 suppress tumorigenesis in lung cancer by inhibiting SMURF2-induced TGF-β receptor I ubiquitination

SMURF2 is a member of the HECT family of E3 ubiquitin ligases that have important roles as a negative regulator of transforming growth factor‐β (TGF‐β) signaling through ubiquitin‐mediated degradation of TGF‐β receptor I. However, the regulatory mechanism of SMURF2 is largely unknown. In this study, we identified that micro(mi)R‐195 and miR‐497 putatively target SMURF2 using several target prediction databases. Both miR‐195 and miR‐497 bind to the 3′‐UTR of the SMURF2 mRNA and inhibit SMURF2 expression. Furthermore, miR‐195 and miR‐497 regulate SMURF2‐dependent TβRI ubiquitination and cause the activation of the TGF‐β signaling pathway in lung cancer cells. Upregulation of miR‐195 and miR‐497 significantly reduced cell viability and colony formation through the activation of TGF‐β signaling. Interestingly, miR‐195 and miR‐497 also reduced the invasion ability of lung cancer cells when cells were treated with TGF‐β1. Subsequent in vivo studies in xenograft nude mice model revealed that miR‐195 and miR‐497 repress tumor growth. These findings demonstrate that miR‐195 and miR‐497 act as a tumor suppressor by suppressing ubiquitination‐mediated degradation of TGF‐β receptors through SMURF2, and suggest that miR‐195 and miR‐497 are potential therapeutic targets for lung cancer.

Cost-effective monitoring of microRNA-205 applied as a biomarker using G-quadruplex DNAzyme and 1,1'-oxalyldiimidazole chemiluminescence

Trace levels of microRNA-205, known as a biomarker of lung cancer, in human serum was quantified for the first-time using G-quadruplex DNAzyme linked to detection complementary probe and 1,1'-oxalyldiimidazole chemiluminescence (ODI-CL). First, capture complementary probes immobilized on the surface of paramagnetic bead selectively bound with microRNA-205 existing in human serum. Then, with the addition of detection complementary probe linked to hemin aptamer, a complex linked to hemin aptamer was formed with the completion of hybridization between microRNA-205 and two complementary probes. With the addition of hemin in the solution, finally, a complex linked to G-quadruplex DNAzyme was formed from the interaction of hemin aptamer and hemin. Resorufin, luminescent dye, was formed from the reaction of Amplex Red and H₂O₂ in the presence of the complex linked to DNAzyme acting as a horseradish peroxidase (HRP)-mimicking enzyme. The concentration of resorufin formed from the reaction was dependent on the concentration of microRNA-205 in human serum. Thus, the brightness of resorufin emitted in ODI-CL reaction was enhanced with the increase of microRNA-205. The limit of detection (LOD) of the biosensor with ODI-CL detection, capable of sensing microRNA-205 (dynamic range: 0.4-62.5 nM), was as low as 0.13 nM. It was confirmed that the biosensor can quantify trace levels of microRNA-205 with statistically acceptable accuracy, precision, and recovery.

Differences in the miRNA signatures of chronic musculoskeletal pain patients from neuropathic or nociceptive origins

BACKGROUND

The quality of life for millions of people worldwide is affected by chronic pain. In addition to the effect of chronic pain on well-being, chronic pain has also been associated with poor health conditions and increased mortality. Due to its multifactorial origin, the classification of pain types remains challenging. MicroRNAs (miRNA) are small molecules that regulate gene expression. They are released into the bloodstream in a stable manner under normal and pathological conditions and have been described as potential biomarkers. In the present study, we aimed to investigate whether pain may induce an aberrant, specific dysregulation of miRNA expression, depending on the origin of the pain.

METHODS AND FINDINGS

To do so, we measured the expression changes of 184 circulating miRNAs (c-miRNAs) in the plasma samples of patients with different origins of chronic musculoskeletal pain. After statistical analyses, we identified seven c-miRNA candidates that were differentially expressed depending on the nociceptive or neuropathic origin of the pain. We then developed a two c-miRNA signature (hsa-miR-320a and hsa-miR-98-5p) that was able to correctly classify the pain type of 70% of the patients from the validation set.

CONCLUSIONS

In conclusion, circulating miRNAs are promising biomarkers to identify and characterize the chronic pain type and to further improve its clinical management.

Inhibitory effects of oxymatrine on hepatic stellate cells activation through TGF-β/miR-195/Smad signaling pathway

BACKGROUND

Oxymatrine (OM), a quinolizidine alkaloid extracted from a herb Sophorae Flavescentis Radix, has been used to treat liver fibrotic diseases. However, the mechanism of its anti-fibrosis effects is still unclear. TGF-β/Smad signaling and miR-195 have been proved to paly an important role in hepatic stellate cells (HSCs) activation and liver fibrosis. In this study, we investigated whether OM could inhibit HSCs activation through TGF-β1/miR-195/Smads signaling or not.

METHODS

First, the effects of OM on HSC-T6 in different concentrations and time points were tested by MTT assay. We choose three appropriate concentrations of OM as treatment concentrations in following experiment. By Quantitative Real-time PCR and Western Blot, then we investigated the effect of OM on miR-195, Smad7 and α-SMA's expressions to prove the correlation between OM and the TGF-β1/miR-195/Smads signaling. Last, miR-195 mimic and INF-γ were used to investigate the relation between miR-195 and OM in HSC activation.

RESULTS

Our results showed that the proliferation of HSC was significantly inhibited when OM concentration was higher than 200 μg/mL after 24 h, 100 μg/mL after 48 h and 10 μg/mL after 72 h. The IC₅₀ of OM after 24, 48 and 72 h were 539, 454, 387 μg/mL respectively. OM could down-regulate miR-195 and α-SMA (P < 0.01), while up-regulate Smad7 (P < 0.05). In HSC-T6 cells transfected with miR-195 mimic and pretreated with OM, miR-195 and α-SMA were up-regulated (P < 0.05), and Smad7 was down-regulated (P < 0.05) .

CONCLUSIONS

Given these results, OM could inhibit TGF-β1 induced activation of HSC-T6 proliferation in a dose-dependent and time-dependent manner to some extent. We proved that OM inhibited HSC activation through down-regulating the expression of miR-195 and up-regulating Smad7.

Inhibition of miR-9 attenuates fibroblast proliferation in human hyperplastic scar by regulating TGF-β1

Healing of damaged tissue results in scar development, which can be difficult to manage. The present study was performed to determine the effects of inhibition of the microRNA (miR), miR-9, on the proliferation of fibroblasts in human hyperplastic scar (HS) formation. Samples of HS tissue and normal tissue were isolated from 20 patients, and the fibroblasts were transfected with small-interfering RNA (siRNA) for transforming growth factor beta 1 (TGF-β1), miR-9 mimic, and miR-9 inhibition. TGF-β1 protein and mRNA expression were examined in the fibroblasts and HS tissue samples by Western blotting and RT-PCR, respectively. Moreover, the effects of miR-9 inhibitor and mimic on cell proliferation and apoptosis were also examined in the HS tissue. Protein and mRNA expression levels of TGF-β1 were increased in the HS tissue compared to adjacent normal tissues. The levels of TGF-β1 mRNA and protein expression were reduced in siRNA-transfected cells. The miR-9 and TGF-β1 mRNA expression levels were reduced in the miR-9 inhibitor treatment group compared to both the negative control (NC) and control groups. Reduced levels of miR-9 and TGF-β1 mRNA expression were observed in the miR-9 inhibitor treatment group compared to the NC and control groups. Moreover, miR-9 inhibitor increased the percentage of apoptotic cells and decreased cell proliferation compared to the NC and control groups. In conclusion, this study showed that miR-9 plays an important role in the proliferation of fibroblasts by regulating TGF-β1 expression in HS tissue.

MicroRNA changes of bone marrow-derived mesenchymal stem cells differentiated into neuronal-like cells by Schwann cell-conditioned medium

Bone marrow-derived mesenchymal stem cells differentiate into neurons under the induction of Schwann cells. However, key microRNAs and related pathways for differentiation remain unclear. This study screened and identified differentially expressed microRNAs in bone marrow-derived mesenchymal stem cells induced by Schwann cell-conditioned medium, and explored targets and related pathways involved in their differentiation into neuronal-like cells. Primary bone marrow-derived mesenchymal stem cells were isolated from femoral and tibial bones, while primary Schwann cells were isolated from bilateral saphenous nerves. Bone marrow-derived mesenchymal stem cells were cultured in unconditioned (control group) and Schwann cell-conditioned medium (bone marrow-derived mesenchymal stem cell + Schwann cell group). Neuronal differentiation of bone marrow-derived mesenchymal stem cells induced by Schwann cell-conditioned medium was observed by time-lapse imaging. Upon induction, the morphology of bone marrow-derived mesenchymal stem cells changed into a neural shape with neurites. Results of quantitative reverse transcription-polymerase chain reaction revealed that nestin mRNA expression was upregulated from 1 to 3 days and downregulated from 3 to 7 days in the bone marrow-derived mesenchymal stem cell + Schwann cell group. Compared with the control group, microtubule-associated protein 2 mRNA expression gradually increased from 1 to 7 days in the bone marrow-derived mesenchymal stem cell + Schwann cell group. After 7 days of induction, microRNA analysis identified 83 significantly differentially expressed microRNAs between the two groups. Gene Ontology analysis indicated enrichment of microRNA target genes for neuronal projection development, regulation of axonogenesis, and positive regulation of cell proliferation. Kyoto Encyclopedia of Genes and Genomes pathway analysis demonstrated that Hippo, Wnt, transforming growth factor-beta, and Hedgehog signaling pathways were potentially associated with neural differentiation of bone marrow-derived mesenchymal stem cells. This study, which carried out successful microRNA analysis of neuronal-like cells differentiated from bone marrow-derived mesenchymal stem cells by Schwann cell induction, revealed key microRNAs and pathways involved in neural differentiation of bone marrow-derived mesenchymal stem cells. All protocols were approved by the Animal Ethics Committee of Institute of Radiation Medicine, Chinese Academy of Medical Sciences on March 12, 2017 (approval number: DWLI-20170311).

Feedback regulation of TGF-β signaling

Transforming growth factor beta (TGF-β) is a multi-functional polypeptide that plays a critical role in regulating a broad range of cellular functions and physiological processes. Signaling is initiated when TGF-β ligands bind to two types of cell membrane receptors with intrinsic Ser/Thr kinase activity and transmitted by the intracellular Smad proteins, which act as transcription factors to regulate gene expression in the nucleus. Although it is relatively simple and straight-forward, this TGF-β/Smad pathway is regulated by various feedback loops at different levels, including the ligand, the receptor, Smads and transcription, and is thus fine-tuned in terms of signaling robustness, duration, specificity, and plasticity. The precise control gives rise to versatile and context-dependent pathophysiological functions. In this review, we firstly give an overview of TGF-β signaling, and then discuss how each step of TGF-β signaling is finely controlled by distinct modes of feedback mechanisms, involving both protein regulators and miRNAs.

Inhibition of TDP43-Mediated SNHG12-miR-195-SOX5 Feedback Loop Impeded Malignant Biological Behaviors of Glioma Cells

Long non-coding RNA (lncRNA) dysregulation is involved in tumorigenesis and regulation of diverse cellular processes in gliomas. lncRNA SNHG12 is upregulated and promotes cell growth in human osteosarcoma cells. TAR-DNA binding protein 43 (TDP43) functions as an oncogene in various tumors by modulating RNA expression. Downregulation of TDP43 or SNHG12 significantly inhibited malignant biological behaviors of glioma cells. miR-195, downregulated in glioma tissues and cells, significantly impaired the malignant progression of glioma cells. TDP43 upregulated miR-195 in an SNHG12-dependent manner. We further revealed that SNHG12 and miR-195 were in an RNA-induced silencing complex (RISC). Inhibition of SNHG12 combined with restoration of miR-195 robustly reduced tumor growth in vivo. SOX5 was overexpressed in glioma tissues and cells. miR-195 targeted SOX5 3′ UTR in a sequence-specific manner. Gelsolin was activated by SOX5. More importantly, SOX5 activated SNHG12 promoter and upregulated its expression, forming a feedback loop. Dysregulation of SNHG12, miR-195, and SOX5 predicted poor prognosis of glioma patients. The present study demonstrated that SNHG12-miR-195-SOX5 feedback loop exerted a crucial role in the regulation of glioma cells’ malignant progression.

MicroRNA-195 Activates Hepatic Stellate Cells In Vitro by Targeting Smad7

Background and Aim

Aberrant activation of the TGF-β1/Smad pathway contributes to the activation of hepatic stellate cells (HSCs). MicroRNA-195 has been shown to regulate the activation of HSCs. The aim of this study was to investigate the role of miRNA-195 in HSCs activation.

Methods

A liver fibrotic rat model induced by diethylnitrosamine was established. Dual luciferase reporter assays were performed to verify that Smad7 was the target of miRNA-195. The expression levels of miR-195, Smad7, and α-SMA in HSC-T6 transfected, respectively, with miR-195 mimic, inhibitor, or control were measured by qRT-PCR. The protein expression of Smad7 was detected by Western blot analysis.

Results

Enhanced miR-195 and decreased Smad7 were observed in diethylnitrosamine-induced liver fibrotic rats (P < 0.05). Dual luciferase reporter assays showed that the miR-195 mimic significantly suppressed the luciferase activity of a reporter plasmid carrying the binding site of miR-195 on the 3′UTR of Smad7 (P < 0.05). The miR-195 mimics activated HSCs, further elevated miR-195 and α-SMA (P < 0.01), and reduced the Smad7 level (P < 0.05). The miR-195 inhibitors blocked the activation of HSCs, reduced the expression of miR-195 and α-SMA (P < 0.01), and upregulated the expression of Smad7 (P < 0.05).

Conclusion

Collectively, we demonstrated that miRNA-195 activated HSCs by targeting Smad7.

The mechanism of TGF-β/miR-155/c-Ski regulates endothelial-mesenchymal transition in human coronary artery endothelial cells

Human coronary artery endothelial cells (HCAECs) have the potential to undergo fibrogenic endothelial–mesenchymal transition (EndMT), which results in matrix-producing fibroblasts and thereby contributes to the pathogenesis of cardiac fibrosis. Recently, the profibrotic cytokine transforming growth factor-β (TGF-β) is shown to be the crucial pathogenic driver which has been verified to induce EndMT. C-Ski is an important regulator of TGF-β signaling. However, the detailed role of c-Ski and the molecular mechanisms by which c-Ski affects TGF-β-induced EndMT in HCAECs are not largely elucidated. In the present study, we treated HCAECs with TGF-β of different concentrations to induce EndMT. We found that overexpression of c-Ski in HCAECs either blocked EndMT via hindering Vimentin, Snail, Slug, and Twist expression while enhancing CD31 expression, with or without TGF-β treatment. In contrast, suppression of c-Ski further enhanced EndMT. Currently, miRNA expression disorder has been frequently reported associating with cardiac fibrosis. By using online tools, we regarded miR-155 as a candidate miRNA that could target c-Ski, which was verified using luciferase assays. C-Ski expression was negatively regulated by miR-155. TGF-β-induced EndMT was inhibited by miR-155 silence; the effect of TGF-β on Vimentin, CD31, Snail, Slug, and Twist could be partially restored by miR-155. Altogether, these findings will shed light on the role and mechanism by which miR-155 regulates TGF-β-induced HCAECs EndMT via c-Ski to affect cardiac fibrosis, and miR-155/c-Ski may represent novel biomarkers and therapeutic targets in the treatment of cardiac fibrosis.

The role of micro-RNA in the regulation of signal pathways in gliomas

Gliomas are invasive brain tumors with high rates of recurrence and mortality. Glioblastoma multiforme (GBM) is the most deadly form of glioma with nearly 100% rate of recurrence and unfavorable prognosis in patients. Micro-RNAs (miR) are the class of wide-spread short non-coding RNAs that inhibit translation via binding to the mRNA of target genes. The aim of the present review is to analyze recent studies and experimental results concerning aberrant expression profiles of miR, which target components of the signaling pathways Hedgehog, Notch, Wnt, EGFR, TGFb, HIF1a in glioma/glioblastoma. Particularly, the interactions of miR with targets of 2-hydroxyglutarate (the product of mutant isocytrate dehydrogenase, R132H IDH1, which is specific for the glioma pathogenesis) have been considered in the present review. Detecting specific miRNAs in tissue and serum may serve as a diagnostic and prognostic tool for glioma, as well as for predicting treatment response of an individual patient, and potentially serving as a mechanism for creating personalized treatment strategies