miR-195 plays a role in steroid resistance of ulcerative colitis by targeting Smad7

Epigenetic regulation and therapeutic strategies in ulcerative colitis

Ulcerative colitis (UC) is an inflammatory bowel disease, and is characterized by the diffuse inflammation and ulceration in the colon and rectum mucosa, even extending to the caecum. Epigenetic modifications, including DNA methylations, histone modifications and non-coding RNAs, are implicated in the differentiation, maturation, and functional modulation of multiple immune and non-immune cell types, and are influenced and altered in various chronic inflammatory diseases, including UC. Here we review the relevant studies revealing the differential epigenetic features in UC, and summarize the current knowledge about the immunopathogenesis of UC through epigenetic regulation and inflammatory signaling networks, regarding DNA methylation, histone modification, miRNAs and lncRNAs. We also discuss the epigenetic-associated therapeutic strategies for the alleviation and treatment of UC, which will provide insights to intervene in the immunopathological process of UC in view of epigenetic regulation.

miRNA Molecules-Late Breaking Treatment for Inflammatory Bowel Diseases?

MicroRNAs (miRNAs) are a group of non-coding RNAs that play a critical role in regulating epigenetic mechanisms in inflammation-related diseases. Inflammatory bowel diseases (IBDs), which primarily include ulcerative colitis (UC) and Crohn's disease (CD), are characterized by chronic recurrent inflammation of intestinal tissues. Due to the multifactorial etiology of these diseases, the development of innovative treatment strategies that can effectively maintain remission and alleviate disease symptoms is a major challenge. In recent years, evidence for the regulatory role of miRNAs in the pathogenetic mechanisms of various diseases, including IBD, has been accumulating. In light of these findings, miRNAs represent potential innovative candidates for therapeutic application in IBD. In this review, we discuss recent findings on the role of miRNAs in regulating inflammatory responses, maintaining intestinal barrier integrity, and developing fibrosis in clinical and experimental IBD. The focus is on the existing literature, indicating potential therapeutic application of miRNAs in both preclinical experimental IBD models and translational data in the context of clinical IBD. To date, a large and diverse data set, which is growing rapidly, supports the potential use of miRNA-based therapies in clinical practice, although many questions remain unanswered.

miR-642a-5p increases glucocorticoid sensitivity by suppressing the TLR4 signalling pathway in THP-1 cells

The incidence rate of ulcerative colitis (UC) is increasing annually, and glucocorticoid (GC) resistance (GCR) is a common cause of UC-induced remission failure. Our previous studies have shown that the expression of miR-642a-5p is downregulated in UC with GCR, suggesting that miR-642a-5p may be related to the GC response. Therefore, we investigated the mechanism by which miR-642a-5p regulates the GC response in THP-1 cells.

We found that after treatment with miR-642a-5p mimics and DEX, the expression levels of glucocorticoid receptor (GR) in the nucleus and NF-κB p65 and p50 in the cytoplasm were increased (P < 0.05). miR-642a-5p mimics transfected into THP-1 cells could synergize with dexamethasone (DEX) to reduce lipopolysaccharide (LPS)-induced inflammatory factor levels such as TNF-α, IL-1β, IL-6 and IL-12 (P < 0.05). Bioinformatics analysis and luciferase reporter assays confirmed that TLR4 is a target gene of miR-642a-5p. miR-642a-5p mimic pretreatment enhanced the inhibitory effect of DEX on TLR4 induced by LPS and inhibited the expression of TLR4 on the cell surface (P < 0.05). Additionally, miR-642a-5p further prevented the nuclear import of NF-κB P65 and inhibited the phosphorylation of ERK, p38 and JNK.

These results suggest that miR-642a-5p can inhibit the inflammation by suppressing the TLR4 signalling pathway in THP-1 cells. It also highlights the TLR4 signalling pathway as a potential therapeutic target in anti-inflammation.

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miR-642a-5p can inhibit the TLR4 signalling pathway induced by LPS and increase the glucocorticoid sensitivity in THP-1 cells.

Impact of the Exposome on the Epigenome in Inflammatory Bowel Disease Patients and Animal Models

Inflammatory bowel diseases (IBD) are chronic inflammatory disorders of the gastrointestinal tract that encompass two main phenotypes, namely Crohn's disease and ulcerative colitis. These conditions occur in genetically predisposed individuals in response to environmental factors. Epigenetics, acting by DNA methylation, post-translational histones modifications or by non-coding RNAs, could explain how the exposome (or all environmental influences over the life course, from conception to death) could influence the gene expression to contribute to intestinal inflammation. We performed a scoping search using Medline to identify all the elements of the exposome that may play a role in intestinal inflammation through epigenetic modifications, as well as the underlying mechanisms. The environmental factors epigenetically influencing the occurrence of intestinal inflammation are the maternal lifestyle (mainly diet, the occurrence of infection during pregnancy and smoking); breastfeeding; microbiota; diet (including a low-fiber diet, high-fat diet and deficiency in micronutrients); smoking habits, vitamin D and drugs (e.g., IBD treatments, antibiotics and probiotics). Influenced by both microbiota and diet, short-chain fatty acids are gut microbiota-derived metabolites resulting from the anaerobic fermentation of non-digestible dietary fibers, playing an epigenetically mediated role in the integrity of the epithelial barrier and in the defense against invading microorganisms. Although the impact of some environmental factors has been identified, the exposome-induced epimutations in IBD remain a largely underexplored field. How these environmental exposures induce epigenetic modifications (in terms of duration, frequency and the timing at which they occur) and how other environmental factors associated with IBD modulate epigenetics deserve to be further investigated.

Differentially Expressed miRNAs in Ulcerative Colitis and Crohn’s Disease

Differential microRNA (miRNA or miR) regulation is linked to the development and progress of many diseases, including inflammatory bowel disease (IBD). It is well-established that miRNAs are involved in the differentiation, maturation, and functional control of immune cells. miRNAs modulate inflammatory cascades and affect the extracellular matrix, tight junctions, cellular hemostasis, and microbiota. This review summarizes current knowledge of differentially expressed miRNAs in mucosal tissues and peripheral blood of patients with ulcerative colitis and Crohn’s disease. We combined comprehensive literature curation with computational meta-analysis of publicly available high-throughput datasets to obtain a consensus set of miRNAs consistently differentially expressed in mucosal tissues. We further describe the role of the most relevant differentially expressed miRNAs in IBD, extract their potential targets involved in IBD, and highlight their diagnostic and therapeutic potential for future investigations.

The Impact of MicroRNAs during Inflammatory Bowel Disease: Effects on the Mucus Layer and Intercellular Junctions for Gut Permeability

Research on inflammatory bowel disease (IBD) has produced mounting evidence for the modulation of microRNAs (miRNAs) during pathogenesis. MiRNAs are small, non-coding RNAs that interfere with the translation of mRNAs. Their high stability in free circulation at various regions of the body allows researchers to utilise miRNAs as biomarkers and as a focus for potential treatments of IBD. Yet, their distinct regulatory roles at the gut epithelial barrier remain elusive due to the fact that there are several external and cellular factors contributing to gut permeability. This review focuses on how miRNAs may compromise two components of the gut epithelium that together form the initial physical barrier: the mucus layer and the intercellular epithelial junctions. Here, we summarise the impact of miRNAs on goblet cell secretion and mucin structure, along with the proper function of various junctional proteins involved in paracellular transport, cell adhesion and communication. Knowledge of how this elaborate network of cells at the gut epithelial barrier becomes compromised as a result of dysregulated miRNA expression, thereby contributing to the development of IBD, will support the generation of miRNA-associated biomarker panels and therapeutic strategies that detect and ameliorate gut permeability.

MicroRNA-195-5p Downregulation Inhibits Endothelial Mesenchymal Transition and Myocardial Fibrosis in Diabetic Cardiomyopathy by Targeting Smad7 and Inhibiting Transforming Growth Factor Beta 1-Smads-Snail Pathway

Diabetic cardiomyopathy (DCM) is a complication of diabetes mellitus, which is associated with fibrosis and microRNAs (miRs). This study estimated the mechanism of miR-195-5p in endothelial mesenchymal transition (EndMT) and myocardial fibrosis in DCM. After the establishment of DCM rat models, miR-195-5p was silenced by miR-195-5p antagomir. The cardiac function-related indexes diastolic left ventricular anterior wall (LVAW, d), systolic LVAW (d), diastolic left ventricular posterior wall (LVPW, d), systolic LVPW (d), left ventricular ejection fraction (LVEF), and fractional shortening (FS) were measured and miR-195-5p expression in myocardial tissue was detected. Myocardial fibrosis, collagen deposition, and levels of fibrosis markers were detected. Human umbilical vein endothelial cells (HUVECs) were exposed to high glucose (HG) and miR-195-5p was silenced. The levels of fibrosis proteins, endothelial markers, fibrosis markers, EndMT markers, and transforming growth factor beta 1 (TGF-β1)/Smads pathway-related proteins were measured in HUVECs. The interaction between miR-195-5p and Smad7 was verified. In vivo, miR-195-5p was highly expressed in the myocardium of DCM rats. Diastolic and systolic LVAW, diastolic and systolic LVPW were increased and LVEF and FS were decreased. Inhibition of miR-195-5p reduced cardiac dysfunction, myocardial fibrosis, collagen deposition, and EndMT, promoted CD31 and VE-cadehrin expressions, and inhibited α-SMA and vimentin expressions. In vitro, HG-induced high expression of miR-195-5p and the expression changes of endothelial markers CD31, VE-cadehrin and fibrosis markers α-SMA and vimentin were consistent with those in vivo after silencing miR-195-5p. In mechanism, miR-195-5p downregulation blocked EndMT by inhibiting TGF-β1-smads pathway. Smad7 was the direct target of miR-195-5p and silencing miR-195-5p inhibited EndMT by promoting Smad7 expression. Collectively, silencing miR-195-5p inhibits TGF-β1-smads-snail pathway by targeting Smad7, thus inhibiting EndMT and alleviating myocardial fibrosis in DCM.

Exosomes derived from T regulatory cells relieve inflammatory bowel disease by transferring miR-195a-3p

Previous studies have demonstrated the therapeutic effects of regulatory T (Treg) cells on inflammatory bowel disease (IBD), but the mechanism is not well-understood. Exosomes have been proposed as a novel mechanism underlying the action of Tregs. This study aimed to investigate the therapeutic effects of exosomes secreted by Treg cells (Treg-Exo) on IBD and to explore the underlying mechanism. Treg-Exo was isolated from BALB/c mouse spleen mononuclear cells and then injected into a murine model of IBD induced by dextran sodium sulfate (DSS) exposure. A co-culture model of Treg-Exo and colonic epithelial YAMC cells in the presence of TNF-α was used to investigate the communication between Tregs and intestinal epithelial cells. in vitro results showed that Treg-Exo could be transferred to YAMC cells where Treg-Exo promoted cell proliferation and inhibited cell apoptosis. Animal experiments showed that Treg-Exo administration alleviated the DSS-induced IBD in mice. The therapeutic effects of Treg-Exo both in vitro and in vivo were eliminated when miR-195a-3p expression was inhibited in Treg-Exo. The pro-apoptotic Caspase 12 was identified as a direct target of miR-195a-3p. In conclusion, Treg-Exo alleviated the DSS-induced IBD through transferring miR-195a-3p.

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).

The involvement of miR-6615-5p/Smad7 axis and immune imbalance in ammonia-caused inflammatory injury via NF-κB pathway in broiler kidneys

Ammonia (NH₃), a toxic gas, has deleterious effects on chicken health in intensive poultry houses. MicroRNA can mediate inflammation. The complex molecular mechanisms underlying NH₃ inhalation-caused inflammation in animal kidneys are still unknown. To explore the mechanisms, a broiler model of NH₃ exposure was established. Kidney samples were collected on day 14, 28, and 42, and meat yield was evaluated on day 42. We performed histopathological examination, detected miR-6615-5p and mothers against decapentaplegic homolog 7 (Smad7), and determined inflammatory factors and cytokines in kidneys. The results showed that excess NH₃ reduced breast weight and thigh weight, which indicated that excess NH₃ impaired meat yield of broilers. Besides, kidney tissues displayed histopathological changes after NH₃ exposure. Meanwhile, the increases of inducible nitric oxide synthase (iNOS) activity and nitric oxide content were obtained. The mRNA and protein expression of inflammatory factors, including nuclear factor-κB (NF-κB), cyclooxygenase-2, prostaglandin E synthases, and iNOS increased, indicating that NF-κB pathway was activated. T-helper (Th) 1 and regulatory T (Treg) cytokines were downregulated, whereas Th2 and Th17 cytokines were upregulated, suggesting the occurrence of Th1/Th2 and Treg/Th17 imbalances. In addition, we found that Smad7 was a target gene of miR-6615-5p in chickens. After NH₃ exposure, miR-6615-5p expression was elevated, and Smad7 mRNA and protein expression were reduced. In summary, our results suggest that NH₃ exposure negatively affected meat yield; and miR-6615/Smad7 axis and immune imbalance participated in NH₃-induced inflammatory injury via the NF-κB pathway in broiler kidneys. This study is helpful to understand the mechanism of NH₃-induced kidney injury and is meaningful to poultry health and breed aquatics.

The role of cigarette smoke-induced epigenetic alterations in inflammation

Background

Exposure to cigarette smoke (CS) is a major threat to human health worldwide. It is well established that smoking increases the risk of respiratory diseases, cardiovascular diseases and different forms of cancer, including lung, liver, and colon. CS-triggered inflammation is considered to play a central role in various pathologies by a mechanism that stimulates the release of pro-inflammatory cytokines. During this process, epigenetic alterations are known to play important roles in the specificity and duration of gene transcription.

Main text

Epigenetic alterations include three major modifications: DNA modifications via methylation; various posttranslational modifications of histones, namely, methylation, acetylation, phosphorylation, and ubiquitination; and non-coding RNA sequences. These modifications work in concert to regulate gene transcription in a heritable fashion. The enzymes that regulate these epigenetic modifications can be activated by smoking, which further mediates the expression of multiple inflammatory genes. In this review, we summarize the current knowledge on the epigenetic alterations triggered by CS and assess how such alterations may affect smoking-mediated inflammatory responses.

Conclusion

The recognition of the molecular mechanisms of the epigenetic changes in abnormal inflammation is expected to contribute to the understanding of the pathophysiology of CS-related diseases such that novel epigenetic therapies may be identified in the near future.

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.

MicroRNAs, intestinal inflammatory and tumor

Colorectal cancer (CRC) is the third most malignant tumor. Inflammatory bowel disease (IBD) can increase the risk of colorectal cancer. And colitis-associated cancer (CAC) is a CRC subtype, representing the inflammation-related colorectal cancer. For the past decades, we have known that ectopic microRNA (miRNA) expression was involved in the pathogenesis of IBD and CRC, playing a pivotal role in the progression of inflammation to colorectal cancer. Thus, this review provides the recent advances in altered human tissue-specific miRNAs that contribute to IBD, CRC and CAC pathogenesis, diagnosis and treatment. Meanwhile, the potential utilization of miRNAs as novel therapeutic targets for the prevention of CRC was also discussed.

miR-195 suppresses abdominal aortic aneurysm through the TNF-α/NF-κB and VEGF/PI3K/Akt pathway

In the present study, the function of microRNA (miR)‑195 on abdominal aortic aneurysm (AAA) and its possible mechanism were investigated. Reverse transcription‑quantitative polymerase chain reaction analysis was used to detect the expression of miR‑195 in patients with AAA. The expression levels of miR‑195 in patients with AAA were effectively increased. The present study also used miR‑195 mimics to increase the expression of miR‑195, and ELISA kits and western blot analysis were used to analyze the levels of interleukin (IL)‑1β and IL‑6, and the protein expression levels of matrix metalloproteinase (MMP)‑2, MMP‑9, tumor necrosis factor (TNF)‑α, nuclear factor (NF)‑κB, vascular endothelial growth factor (VEGF), phosphoinositide 3‑kinase (PI3K) and phosphorylated (p‑)Akt. The overexpression of miR‑195 promoted the levels of IL‑1β and IL‑6, induced the protein expression of MMP‑2 and MMP‑9, upregulated the protein expression of TNF‑α and NF‑κB, and suppressed the protein expression levels of VEGF, PI3K and p‑Akt in angiotensin II‑vascular smooth muscle cells. In addition, TNF‑α promoted the pre‑inflammatory effect of miR‑195 on the protein expression levels of TNF‑α and NF‑κB, levels of IL‑1β and IL‑6, and protein expression levels of MMP‑2 and MMP‑9 in the angiotensin II‑vascular smooth muscle cells. Suppression of PI3K promoted the pre‑inflammatory effect of miR‑195 on the protein expression of PI3K, p‑Akt and VEGF, the levels of IL‑1β and IL‑6, and the protein expression of MMP‑2 and MMP‑9 in angiotensin II‑vascular smooth muscle cells. Combined, these results suggested that miR‑195 suppressed AAA inflammation through the TNF‑α/NF‑κB and VEGF/PI3K/Akt pathways.

miR-590 promotes the proliferation of HUMSCs and induces ECM synthesis by targeting Smad7

MicroRNA (miR)-590 has been established to be a promoter of cell proliferation, migration and invasion, and an inhibitor of apoptosis in numerous cancer cell lines. However, its effects on non-cancer cells remain to be elucidated. miR-590 was transfected into human umbilical cord mesenchymal stem cells (HUMSCs), and the cell proliferation rate was determined using a Cell-Light 5-ethynyl-20-deoxyuridine Apollo 567 kit and the presence of extracellular matrix (ECM) proteins were detected using western blot analysis and immunofluorescence microscopy. Using bioinformatic analysis and dual-luciferase assays, the novel target miR-590 was identified. In addition, the effects of miR-590 on cell proliferation and ECM enhancement were also evaluated. The results of the present study demonstrated that miR-590 interacts directly with the 3'-untranslated region of Mothers Against Decapentaplegic Homolog 7 (Smad7), which is an important factor in transforming growth factor-β signaling pathway. Overexpression of miR-590 downregulated Smad7 expression at the mRNA and protein level, and subsequently resulted in cell proliferation and ECM accumulation. Additionally, the transfection of small interfering RNA targeting Smad7 in HUMSCs produced similar effects on cell proliferation and ECM to the overexpression of miR-590. The results of the present study indicated that miR-590 affects HUMSC proliferation by directly targeting Smad7.

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.

Role of MiRNAs in Inflammatory Bowel Disease

Inflammatory bowel diseases (IBD), mainly including Crohn's disease and ulcerative colitis, are characterized by chronic inflammation of the gastrointestinal tract. Despite improvements in detection, drug treatment and surgery, the pathogenesis of IBD has not been clarified. A number of miRNAs have been found to be involved in the initiation, development and progression of IBD, and they may have the potential to be used as biomarkers and therapeutic targets. Here, we have summarized the recent advances about the roles of miRNAs in IBD and analyzed the contribution of miRNAs to general diagnosis, differential diagnosis and activity judgment of IBD. Furthermore, we have also elaborated the promising role of miRNAs in IBD-related cancer prevention and prognosis prediction.

Assessment of disease activity in pediatric ulcerative colitis

To date, we encounter more and more pediatric patients with ulcerative colitis (UC). For yet unclear reasons, UC in pediatric patients seems to be a more aggressive and extensive disease than in their adult counterparts. In the majority of pediatric patients, the disease presents as pancolitis. The severity of the disease is reflected in the high use of corticosteroids and immunosuppressants and a high rate of surgery for medically refractory patients. The means by which to assess disease activity or to accurately predict its course are far from optimal. This review summarizes the current knowledge on the means for assessing UC activity in children. Research for developing new tools by which to monitor and forecast disease activity, are needed in all areas including invasive endoscopy, clinical evaluation, and treatment follow-up.

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

Transforming growth factor-β (TGF-β) proteins are important cytokines in the occurrence and development of tumors. However, its neural functions in glioma are still not understood. In the present study, we evaluated the effects of TGF-β1 on glioma cell line U87. miR-205 and miR-195 were involved in TGF-β1 signaling pathway. Quantitative real-time PCR was used to detect miR-205 and miR-195 levels in human glioma tissue samples and U87 cells treated with different concentrations of TGF-β1. Enzyme-linked immunosorbent assay (ELISA) was performed to determine TGF-β1 in the glioma patients peripheral blood. In vitro, U87 cells were transfected with mimics or inhibitors of miR-205 and miR-195. SMAD proteins were assayed by western blotting. Luciferase assay and co-immunoprecipitation (Co-IP)were used to determine the relationships between miR-205 and SMAD2, miR-195 and SMAD7. Effects of miR-205 and miR-195 on glioma cell proliferation and invasion using colony forming and cell migration assays. It was shown that miR-205 was decreased in glioma tissue, but miR-195 and TGF-β1 was increased. In addition, TGF-β1 concentration was negatively correlated with miR-205 mRNA level, but positively correlated with miR-195 mRNA. In addition, miR-205 was downregulated and miR-195 was upregulated by TGF-β1 in a dose-dependent manner. miR-205 and miR-195 targeted and inhibited SMAD2 and SMAD7 expression, respectively, in U87. High expression of miR-205 but not miR-195 reduced SMAD2 and SMAD4 heteromer formation. In addition, it was also shown that miR-205 overexpression inhibited U87 proliferation and invasion efficiently. All the results suggested that miR-205 and miR-195 participated in the TGF-β1 signaling pathway and showed opposite effects in glioma. These findings contribute to the understanding of TGF-β1 function in glioma.