Identification of non-invasive biomarkers for chronic atrophic gastritis from serum exosomal microRNAs.

BACKGROUND: Serum exosomal microRNAs (miRNAs) have been suggested as novel biomarkers for various diseases, especially gastric cancer (GC). But circulating biomarkers for Chronic atrophic gastritis (CAG) which is defined as precancrerous lesions of GC remain largely elusive. To investigate serum exosomal miRNAs that are differently expressed in CAG patients and Chronic nonatrophic gastritis (CNAG) may be helpful for its diagnosis and therapy. METHODS: Patients were recruited according to the diagnosis and exclusioncriteria. RNA was extracted from serum exosomes of 30 CAG and 30 CNAG patients. The miRNA expression profiles were analyzed by next generation sequencing and were validated by qRT-PCR. Receiver operating characteristic (ROC) analysis has been used to evaluate the diagnostic value. RESULTS: 30 CAG patients and 30 CNAG patients were recruited in our study. sRNA-seq results showed that hsa-miR-3591-3p, - 122-3p, and - 122-5p of the top 10 miRNAs (hsa-miR-148a-3p, - 122-3p, - 486-3p, -451a, - 122-5p, - 3591-3p, - 486-5p, -151a-3p, -92a-3p, -320a) were significantly upregulated in exosomes from CAG patients versus those from CNAG patients, but hsa-miR-451a, -151a-3p, and -92a-3p were significantly downregulated. Furthermore, qRT-PCR analysis confirmed that hsa-miR-122-5p and hsa-miR-122-3p were significantly upregulated in CAG samples, but hsa-miR-122-3p hadnot a steable expression. ROC curves showed that the AUC for hsa-miR-122-5p was 0.67 (95% CI 0.52-0.82, SE 62%, SP 86%). A sum of the four miRNAs (panel 1, hsa-miR-122-5p, -451a, -151a-3p, and -92a-3p) did not significantly improve the diagnostic potential (AUC 0.63, 95% CI 0.47 to 0.78). Correlation analysis showed that the expression of hsa-miR-122-5p differed significantly between patients based on atrophic (Moderate atrophic vs. Absent, P value was 0.036.) and IM (compare moderate-severe, absent and mild P values were 0.001 and 0.014, respectively). However, there were no differences between groups based on age, gender, dysplasia, or chronic or active inflammation. CONCLUSION: These results suggested that hsa-miR-122-5p in serum exosomes might serve as a potential biomarker for CAG diagnosis. TRIAL REGISTRATION: Chinese Clinical Trial Registy ( ChiCTR-IOR-16008027 , Date of Registration:2016-03-01).

Tong-Xie-Yao-Fang improves intestinal permeability in diarrhoea-predominant irritable bowel syndrome rats by inhibiting the NF-κB and notch signalling pathways.

BACKGROUND: Tong-Xie-Yao-Fang (TXYF) has been shown to be effective in diarrhoea-predominant irritable bowel syndrome (IBS-D) patients. However, the underlying mechanism remains to be clarified. The aim of this study was to investigate the efficacy and related mechanisms of TXYF in an IBS-D rat model. METHODS: The IBS-D rat model was established with 4% acetic acid and evaluated by haematoxylin-eosin (HE) staining. Then, IBS-D rats were divided into control, TXYF and rifaximin groups and treated intragastrically with normal saline, TXYF and rifaximin, respectively, for 14 days. The following indicators were measured before and after treatment: defecation frequency, faecal water content (FWC) and colorectal distension (CRD). Histopathological changes in the distal colon were observed after treatment. The expression of OCLN and ZO1 in the distal colon of IBS-D rats reflected the intestinal mucosal permeability, as measured by qRT-PCR, western blot, and enzyme-linked immunosorbent assays (ELISAs). The NF-κB and Notch signalling pathways and inflammation-related factors were investigated. RESULTS: After treatment with TXYF, the defecation frequency, FWC and CRD were significantly lower than those in the model group (P < 0.05). HE staining showed that colonic epithelial cells (CECs) in the IBS-D rats displayed significant oedema, impaired intestinal mucosal integrity and an increased influx of inflammatory cells. A significant reduction in granulocyte and CEC oedema was observed after the administration of TXYF and rifaximin compared to that of the model group and blank group (P < 0.05). TXYF significantly upregulated the expression of OCLN and ZO-1 and downregulated inflammation-related factors (IL-6, IL-1ß, and TNF-α and the chemokine KC) in IBS-D rats compared to those in the model group rats (P < 0.05). In terms of the NF-κB and Notch signalling pathways, the expression of NICD, p-ERK, Hes-1 and p-P65 decreased significantly in the TXYF and rifaximin groups, while the expression of ATOH1 increased significantly compared to that in the model group (P < 0.05). CONCLUSION: TXYF can effectively improve intestinal permeability and enhance intestinal mucosal barrier function, which may be related to inhibition of the inflammatory cascade and the NF-κB and Notch signalling pathways.

Profiling the miRNA-mRNA-lncRNA interaction network in MSC osteoblast differentiation induced by (+)-cholesten-3-one.

BACKGROUND: Our previous study showed that (+)-cholesten-3-one (CN) has the potential to induce the osteoblastic differentiation of mesenchymal stem cells (MSCs). However, the roles of CN in targeting miRNA-mRNA-lncRNA interactions to regulate osteoblast differentiation remain poorly understood. RESULTS: A total of 77 miRNAs (36 upregulated and 41 downregulated) and 295 lncRNAs (281 upregulated and 14 downregulated) were significantly differentially expressed during CN-induced MSC osteogenic differentiation. Bioinformatic analysis identified that several pathways may play vital roles in MSC osteogenic differentiation, such as the vitamin D receptor signalling, TNF signalling, PI3K-Akt signalling, calcium signalling, and mineral absorption pathways. Further bioinformatic analysis revealed 16 core genes, including 6 mRNAs (Vdr, Mgp, Fabp3, Fst, Cd38, and Col1a1), 5 miRNAs (miR-483, miR-298, miR-361, miR-92b and miR-155) and 5 lncRNAs (NR_046246.1, NR_046239.1, XR_086062.1, XR_145872.1 and XR_146737.1), that may play important roles in regulating the CN-induced osteogenic differentiation of MSCs. Verified by the luciferase reporter, AR-S, qRT-PCR and western blot assays, we identified one miRNA (miR-298) that may enhance the osteogenic differentiation potential of MSCs via the vitamin D receptor signalling pathway. CONCLUSIONS: This study revealed the global expression profile of miRNAs and lncRNAs involved in the Chinese medicine active ingredient CN-induced osteoblast differentiation of MSCs for the first time and provided a foundation for future investigations of miRNA-mRNA-lncRNA interaction networks to completely illuminate the regulatory role of CN in MSC osteoblast differentiation.

MiR-144 Increases Intestinal Permeability in IBS-D Rats by Targeting OCLN and ZO1.

BACKGROUND/AIMS: Irritable bowel syndrome with diarrhoea (IBS-D) is a chronic, functional bowel disorder characterized by abdominal pain or diarrhoea and altered bowel habits, which correlate with intestinal hyperpermeability. MicroRNAs (miRNAs) are involved in regulating intestinal permeability in IBS-D. However, the role of miRNAs in regulating intestinal permeability and protecting the epithelial barrier remains unclear. Our goals were to (i) identify differential expression of miRNAs and their targets in the distal colon of IBS-D rats; (ii) verify in vitro whether occludin (OCLN) and zonula occludens 1 (ZO1/TJP1) were direct targets of miR-144 and were down-regulated in IBS-D rats; and (iii) determine whether down-regulation of miR-144 in vitro could reverse the pathological hallmarks of intestinal hyperpermeability via targeting OCLN and ZO1. METHODS: The IBS-D rat model was established using 4% acetic acid and evaluated by haematoxylin-eosin (HE) staining. The distal colon was obtained in order to perform miRNA microarray analysis and to isolate and culture colonic epithelial cells. When differential expression of miRNA was found, the results were verified by qRT-PCR, and the target genes were further explored by bioinformatics analysis. Correlation analyses were carried out to compare the expression of miRNA and target genes. Then, mutants, miRNA mimics and inhibitors of the target genes were constructed and transfected to colonic epithelial cells. qRT-PCR, western blotting, enzyme-linked immunosorbent assays (ELISAs) and dual-luciferase assays were used to investigate the expression of miR-144 and OCLN, ZO1 in IBS-D rats. RESULTS: There were 8 up-regulated and 18 down-regulated miRNAs identified in the IBS-D rat model. Of these, miR-144 was markedly up-regulated and resulted in the down-regulation of OCLN and ZO1 expression. Overexpression of miR-144 by transfection of miR-144 precursor markedly inhibited the expression of OCLN and ZO1. Further studies confirmed that OCLN and ZO1 were direct targets of miR-144. Additionally, intestinal hyperpermeability was enhanced by miR-144 up-regulation and attenuated by miR-144 down-regulation in IBS-D rat colonic epithelial cells. Moreover, rescue experiments showed that overexpression of OCLN and ZO1 significantly eliminated the inhibitory effect of miR-144, which showed a stronger effect on the attenuation of intestinal hyperpermeability. CONCLUSION: Up-regulation of miR-144 could promote intestinal hyperpermeability and impair the protective effect of the epithelial barrier by directly targeting OCLN and ZO1. miR-144 is likely a key regulator of intestinal hyperpermeability and could be a potential therapeutic target for IBS-D.

Berberine Enhances Intestinal Mucosal Barrier Function by Promoting Vitamin D Receptor Activity.

OBJECTIVE: To evaluate if berberine can act on vitamin D receptors (VDR) and thereby regulate the expression of tight junction proteins (TJPs) in irritable bowel syndrame-diarrhea-predominant (IBS-D) rats. METHODS: The newborn rats were induced into IBS-D rat model via neonatal maternal separation combined with acetic acid chemical stimulation. After modeling, the model was evaluated and rats were divided into the control group and berberine treatment groups (0.85, 1.7 and 3.4 mg/kg, once a day for 2 weeks). The distal colon was obtained and colonic epithelial cells (CECs) were isolated and cultured after IBS-D model evaluation. The vitamin D receptor response element (VDRE) reporter gene was determined in the CECs of IBS-D rats to analyze the effect of berberine on the VDRE promoter. VDR overexpression or silencing technology was used to analyze whether VDR plays a role in promoting intestinal barrier repair, and to determine which region of VDR plays a role in berberine-regulated intestinal TJPs. RESULTS: The IBS-D rat model was successfully constructed and the symptoms were improved by berberine in a dose-dependent manner (P<0.05). The activity of VDRE promoter was also effectively promoted by berberine (P<0.05). Berberine increased the expression of TJPs in IBS-D CECs (P<0.05). VDR expression was significantly increased after transfection of different domains of VDR when compared to normal control and basic plasmid groups (all P<0.05). RT-qPCR and Western blot results showed that compared with the blank group, expressions of occludin and zonula occludens-1 were significantly higher in VDR containing groups (all P<0.05). Berberine plus pCMV-Myc-VDR-N group exerted the highest expression levels of occludin and zonula occludens-1 (P<0.05). CONCLUSION: Berberine enhances intestinal mucosal barrier function of IBS-D rats by promoting VDR activity, and the main site of action is the N-terminal region of VDR.

An oligosaccharide marker for rapid authentication of edible bird's nest.

Edible bird's nest (EBN) is a popular and expensive food material. The limited supply and great demand result in the use of adulterants. The authenticity concern is raised due to the lack of appropriate quality markers. Herein, this study aims to provide a specific oligosaccharide marker for rapid EBN authentication. Comparing the benzocaine (ABEE)-labeled saccharide profiles of multiple batches of EBN and adulterants indicates seven unique EBN oligosaccharides. The most abundant one, named BNM001, was selected as a marker and characterized to be Neu5Ac (2-3) Gal by MS and NMR spectra. This new oligosaccharide marker enables a rapid authentication of EBN within 10 min. ABEE labelling of this marker further upgraded the accuracy and sensitivity of the LC-qTOF-MS quantitative analysis. The relative marker content was associated with the quality of EBN products. These results suggest a specific and efficient quality marker for rapid authentication of EBN and related products.

Psoralen accelerates osteogenic differentiation of human bone marrow mesenchymal stem cells by activating the TGF-ß/Smad3 pathway.

Psoralen, one of the active ingredients in Psoralea corylifolia, has been previously reported to regulate the osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs). A previous study revealed that psoralen can regulate the expression levels of microRNA-488 and runt-related transcription factor 2 (Runx2) to promote the osteogenic differentiation of BMSCs. However, the underlying signalling pathway in this process remains to be fully elucidated. BMSCs have also been confirmed to play a key role in the occurrence and development of osteoporosis, and are expected to be potential seed cells in the treatment of osteoporosis. In order to explore the potential signalling pathways of psoralen acting on BMSCs, in the present study, human BMSCs (hBMSCs) were treated with different concentrations of psoralen (0.1, 1, 10 and 100 µmol/l) and the TGF-ß receptor I (RI) inhibitor SB431542 (5 µmol/l) in vitro for 3, 7 or 14 days. Cell Counting Kit-8 and MTT assays were used to measure cell proliferation and cell viability of hBMSCs following psoralen administration. Alkaline phosphatase (ALP) activity and alizarin red S staining were used to assess the osteogenic differentiation ability of hBMSCs. Reverse transcription-quantitative PCR and western blotting were used to measure the expression of osteogenic differentiation-related genes [bone morphogenetic protein 4 (BMP4), osteopontin (OPN), Runx2 and Osterix] and proteins associated with the TGF-ß/Smad3 pathway [TGF-ß1, TGF-ß RI, phosphorylated (p-)Smad and Smad3]. Psoralen was found to increase the proliferation and viability of hBMSCs. Although different concentrations of psoralen enhanced ALP activity and the calcified nodule content in hBMSCs, the enhancement effects were more potent at lower concentrations (0.1, 1 and 10 µmol/l). The expression of BMP4, OPN, Osterix, Runx2, TGF-ß1, TGF-ß RI and p-Smad3 was also promoted by psoralen at lower concentrations (0.1, 1 and 10 µmol/l). In addition, whilst SB431542 could inhibit calcium deposition and osteogenic differentiation-related gene expression in hBMSCs, psoralen effectively reversed the inhibitory effects of SB431542. In conclusion, psoralen accelerates the osteogenic differentiation of hBMSCs by activating the TGF-ß/Smad3 pathway, which may be valuable for the future clinical treatment of osteoporosis.

Ginger relieves intestinal hypersensitivity of diarrhea predominant irritable bowel syndrome by inhibiting proinflammatory reaction.

BACKGROUND: Ginger or ginger extracts have been used in traditional medicine relieve pain caused by diarrhea predominant irritable bowel syndrome (IBS-D), but few data exists about its effectiveness. This present study was to validate the effect of ginger on visceral pain, and to further explore the possible underlying mechanism by which ginger is used to relieve IBS-D intestinal hypersensitivity. METHODS: First, the IBS-D rat model was established by chemical stimulation and acute and chronic pressure stimulation. Then, different dose of ginger were administrated to IBS-D rats and evaluate the defecation frequency, fecal water content (FWC) and abdominal withdrawal reflex (AWR) scores in IBS-D rats. Further, the IBS-D rats were sacrificed to collecte the colonic tissues to evaluate the effect of ginger administration on its pathology and changes of pro-inflammatory factors, and changes of NF-κB pathway. Second, the ginger was taken to HPLC analysis and 6-gingerol was choosen to further experiment. Then, IBS-D rats were treated with different dose of 6-gingerol, and the behavioral evaluation were to evaluate the effect of 6-gingerol on IBS-D rats. Further, colonic epithelial cells (CECs) were collectted and to evaluate the effect of 6-gingerol on the expression of inflammatory factors and changes of NF-κB pathway. RESULTS: The IBS-D rat model was successfully established by chemical stimulation and acute and chronic pressure stimulation. And ginger treatment significantly reduced the defecation frequency, fecal water content and AWR scores in IBS-D rats. Histopathological analysis showed that ginger treatment can significantly reduce colonic edema and promote the recovery of inflammation in IBS-D rats, and the effect is equivalent to rifaximin. Elisa and RT-qPCR showed that ginger inhibited the expression of proinflammatory factors (TNF-α, IL-6, iNOS) in IBS-D rats. Western blot showed IkBα was up-regulated while p-p65 was inhibited under ginger treatment. HPLC analysis showed that 6-gingerol was the main component of ginger, which could improve clinical symptoms in IBS-D rats. Western blot and RT-qPCR showed that 6-gingerol inhibited the expression of proinflammatory factors (TNF-α, IL-6, iNOS) in CECs, and inhibition of IκBα degradation and phosphorylation of p65 involved in NF-κB pathway. CONCLUSION: Ginger and ginger extract could relieve intestinal hypersensitivity of IBS-D by inhibiting proinflammatory response.

Efficacy of Tong-Xie-Yao-Fang granule and its impact on whole transcriptome profiling in diarrhea-predominant irritable bowel syndrome patients: study protocol for a randomized controlled trial.

BACKGROUND: Irritable bowel syndrome (IBS) is one kind of common functional bowel disease with obscure pathogenesis, and exploration about whole transcriptome profiling in IBS-D is still negligible. Conventional medications have limited effects, which makes focus shifted to traditional Chinese medicine (TCM). Tong-Xie-Yao-Fang, as a classic herbal formula in TCM, is pretty effective and safe for the treatment of diarrhea-predominant irritable bowel syndrome (IBS-D), but the underlying therapeutic mechanism remains unknown. We aim to verify the efficacy and safety of TXYF granule (the formula particles mixed together) in IBS-D and elucidate the gene-level mechanism of IBS-D and therapeutic targets of TXYF granule based on whole transcriptome analysis. METHODS/DESIGN: This is a randomized, double-blind, and placebo-controlled clinical trial consisting of 2 weeks of run-in period, 12 weeks of treatment period, and 8 weeks of follow-up period. We will enroll 120 participants with IBS-D, who will be randomly assigned to the TXYF granule group and the placebo group, and recruit additional 10 healthy individuals as controls for mechanistic outcome. The two groups respectively take TXYF granule or placebo orally for treatment. The primary outcome is the response rate of IBS-Symptom Severity Score (IBS-SSS). The secondary outcomes include adequate relief (AR), IBS-Quality of Life Questionnaire (IBS-QOL), and long-term efficacy. Mechanistic outcome is the whole transcriptome profiling of the intestinal mucosae from IBS participants before and after the treatment and healthy individuals. DISCUSSION: This trial will prove the effectiveness and safety of TXYF granule with high-quality evidence and provide a penetrating and comprehensive perspective on the molecular mechanism of IBS-D by whole transcriptome analysis, which makes us pinpoint specific biomarkers of IBS-D and therapeutic targets of TXYF. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR-IOR-1900021785 . Registered on 9 March 2019.

Lactobacillus casei LC01 Regulates Intestinal Epithelial Permeability through miR-144 Targeting of OCLN and ZO1.

Our previous report determined that miR-144 is a key regulator of intestinal epithelial permeability in irritable bowel syndrome with diarrhea (IBS-D) rats. Recent evidence has shown that lactobacilli play an important role in the relief of IBS-D symptoms. However, few studies have addressed the mechanisms by which microRNAs and lactobacilli exert their beneficial effects on intestinal epithelial permeability. Hence, to elucidate whether miRNAs and lactobacilli play roles in intestinal epithelial barrier regulation, we compared miRNA expression levels in intestinal epithelial cells (IECs) under Lactobacillus casei (L. casei LC01) treatment. IECs and L. casei LC01 were co-cultured and then subjected to microRNA microarray assay. qRT-PCR, western blot and ELISA were used to detect the expression of occludin (OCLN) and zonula occludens 1 (ZO1/TJP1). The interaction between miRNAs and L. casei LC01 acting in IECs was investigated through transfection of RNA oligoribonucleotides and pcDNA 3.1 plasmid. The results are as follows: 1) L. casei LC01 decreased the expression of miR-144 and FD4 and promoted OCLN and ZO1 expression in IECs; 2) L. casei LC01 enhanced the barrier function of IECs via downregulation of miR-144 and upregulation of OCLN and ZO1; 3) Under L. casei LC01 treatment, OCLN and ZO1 overexpression could partially eliminate the promoting effect of miR-144 on intestinal permeability in IECs. Our results demonstrate that L. casei LC01 regulates intestinal permeability of IECs through miR-144 targeting of OCLN and ZO1. L. casei LC01 can be a possible therapeutic target for managing dysfunction of the intestinal epithelial barrier.

miR­488 negatively regulates osteogenic differentiation of bone marrow mesenchymal stem cells induced by psoralen by targeting Runx2.

It has been previously reported that psoralen, one of the active ingredients in Psoralea corylifolia, could induce osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs), suggesting its potential to treat osteoporosis. Additionally, runt­related transcription factor 2 (Runx2) is a transcription factor that plays vital roles in BMSC osteogenic differentiation. However, whether and how microRNAs (miRNAs/miRs) modulate osteogenic differentiation induced by psoralen have not yet been examined, to the best of the authors' knowledge. The present study aimed to identify the miRNA target genes that regulate osteogenic differentiation of BMSCs induced by psoralen. A Cell Counting Kit­8 assay and alizarin red staining were used to detect the viability and osteogenic differentiation of BMSCs, respectively, under treatment with psoralen. miRNA microarray analysis was performed to identify the differentially expressed miRNAs under treatment with psoralen. A bioinformatics analysis and a luciferase reporter assay were conducted to identify the targets of miR­488. Finally, the mechanisms of miR­488 in psoralen­induced BMSC osteogenic differentiation were investigated using overexpression or inhibition methods in vitro. Cell viability was elevated and osteogenic differentiation of BMSCs was improved under treatment with psoralen. miRNA microarray analysis and further validation by reverse transcription­quantitative PCR revealed that miR­488 was downregulated during psoralen­induced BMSC osteogenic differentiation. Bioinformatics analysis and experimental validation by a luciferase reporter assay identified Runx2 as a potential target of miR­488. Overexpression of miR­488 by transfection with miR­488 mimics markedly inhibited the expression of Runx2, Osterix and alkaline phosphatase, whereas, the inhibition of miR­488 expression by the miR­488 inhibitor promoted their expression compared with the control. Rescue assays demonstrated that Runx2 overexpression partially rescued the inhibitory effect of miR­488 on BMSC osteogenic differentiation. The present results suggested that miR­488 is a negative regulator of psoralen­induced BMSC osteogenic differentiation by targeting Runx2, providing a possible therapeutic target for osteoporosis.

Berberine improves intestinal epithelial tight junctions by upregulating A20 expression in IBS-D mice.

To investigate effects of berberine exerts on A20 expression and regulation of intestinal epithelial tight junctions via the TNF-α-NF-κB-MLCK pathway in Diarrhea-Predominant Irritable Bowel Syndrome (IBS-D). C57BL/6 wild type (WT) and A20 IEC-KO mice (48 each) were randomly divided into normal control (NC), model control (MC), rifaximin and berberine groups (12 mice per group). An experimental model of IBS-D was established using 4% acetic acid and evaluated by haematoxylin-eosin (HE) staining. rifaximin and berberine mice were treated with rifaximin and berberine, respectively. Intestinal epithelial space of WT berberine mice improved more than A20 IEC-KO berberine mice compared to MC mice. WT berberine mice exhibited greater expression of A20 compared with MC mice(P < 0.01). TNF-α, NF-kB p65, MLCK, MLC, TRAF6 and RIP1 levels in A20 IEC-KO and WT berberine mice were all decreased compared to MC mice(P all<0.05). NF-κB p65, MLCK and TRAF6 levels were increased in A20 IEC-KO berberine mice as compared to WT berberine mice (P all<0.05). Intestinal epithelial levels of occludin, claudin-1, ZO-1 and F-actin increased in all berberine mice (P all<0.01-0.05), while occludin, claudin-1, and ZO-1 levels were lower in A20 IEC-KO berberine mice(P < 0.05). Berberine downregulates abnormal activation of the TNF-α-NF-κB-MLCK pathway by upregulating expression of A20 in a mouse model of IBS-D, thereby protecting intestinal epithelial tight junctions and repairing the damage IBS-D causes to the intestinal epithelial barrier.

MicroRNA-200a Targets Cannabinoid Receptor 1 and Serotonin Transporter to Increase Visceral Hyperalgesia in Diarrhea-predominant Irritable Bowel Syndrome Rats.

BACKGROUND/AIMS: MicroRNAs (miRNAs) were reported to be responsible for intestinal permeability in diarrhea-predominant irritable bowel syndrome (IBS-D) rats in our previous study. However, whether and how miRNAs regulate visceral hypersensitivity in IBS-D remains largely unknown. METHODS: We established the IBS-D rat model and evaluated it using the nociceptive visceral hypersensitivity test, myeloperoxidase activity assay, restraint stress-induced defecation, and electromyographic (EMG) activity. The distal colon was subjected to miRNA microarray analysis followed by isolation and culture of colonic epithelial cells (CECs). Bioinformatic analysis and further experiments, including dual luciferase assays, quantitative real-time polymerase chain reaction, western blot, and enzyme-linked immunosorbent assay, were used to detect the expression of miRNAs and how it regulates visceral hypersensitivity in IBS-D rats. RESULTS: The IBS-D rat model was successfully established. A total of 24 miRNAs were differentially expressed in the distal colon of IBS-D rats; 9 were upregulated and 15 were downregulated. Among them, the most significant upregulation was miR-200a, accompanied by downregulation of cannabinoid receptor 1 (CNR1) and serotonin transporter (SERT). MiR-200a mimic markedly inhibited the expression of CNR1/SERT. Bioinformatic analysis and luciferase assay confirmed that CNR1/SERT are direct targets of miR-200a. Rescue experiments that overexpressed CNR1/SERT significantly abolished the inhibitory effect of miR-200a on the IBS-D rats CECs. CONCLUSIONS: This study suggests that miR-200a could induce visceral hyperalgesia by targeting the downregulation of CNR1 and SERT, aggravating or leading to the development and progression of IBS-D. MiR-200a may be a regulator of visceral hypersensitivity, which provides potential targets for the treatment of IBS-D.

MiR-351 negatively regulates osteoblast differentiation of MSCs induced by (+)-cholesten-3-one through targeting VDR.

Our previous reports indicated that (+)-cholesten-3-one induces osteogenic differentiation of bone marrow mesenchymal stem cells (MSCs) by activating vitamin D receptor (VDR). However, whether and how miRNAs modulate osteogenic differentiation induced by (+)-cholesten-3-one have not been explored. In this study, miRNA array profiling and further validation by quantitative real-time PCR revealed that miR-351 was downregulated during (+)-cholesten-3-one-induced osteogenic differentiation of MSCs. Overexpression of miR-351 by miR-351 precursor transfection markedly inhibited the expression of osteoblast-specific genes, such as alkaline phosphatase (ALP), collagen type II, osteopontin (OPN), and runt-related transcription factor 2 (RUNX2), which consequently decreased a number of calcium mineralized nodules. Inhibition of miR-351 function by anti-miR-351 promoted expression of osteoblast-specific genes. Our results suggest that miR-351 is a negative regulator of osteoblast differentiation of MSCs induced by (+)-cholesten-3-one. Target prediction analysis tools and experimental validation by luciferase 3'UTR reporter assay identified VDR as a direct target of miR-351. miR-351 inhibited the expression of the VDR, which played a critical role in the control of osteogenic differentiation of MSCs. Importantly, overexpression of VDR significantly abolished the inhibitory effect of miR-351 on (+)-cholesten-3-one induced osteogenic differentiation. Taken together, our results demonstrate that miR-351 negatively regulates osteoblast differentiation of MSCs induced by (+)-cholesten-3-one through targeting VDR. These findings provid evidence that miR-351 can bea possible therapeutic target for bone repair and regeneration.

(+)-Cholesten-3-one induces osteogenic differentiation of bone marrow mesenchymal stem cells by activating vitamin D receptor.

In our previous reports, it was revealed that steroids in traditional Chinese medicine (TCM) have the therapeutic potential to treat bone disease. In the present study, an in vitro model of a vitamin D receptor response element (VDRE) reporter gene assay in mesenchymal stem cells (MSCs) was used to identify steroids that enhanced osteogenic differentiation of MSCs. (+)-cholesten-3-one (CN), which possesses a ketone group that is modified in cholesterol and cholesterol myristate, effectively promoted the activity of the VDRE promoter. Phenotypic cellular analysis indicated that CN induced differentiation of MSCs into osteogenic cells and increased expression of specific osteogenesis markers, including alkaline phosphatase, collagen II and Runt-related transcription factor 2. Furthermore, CN significantly increased the expression of osteopontin, the target of the vitamin D receptor (VDR), which indicated that CN may activate vitamin D receptor signaling. Over-expression of VDR or knockdown studies with VDR-small interfering RNA revealed that the pro-differentiation effects induced by CN required VDR. Furthermore, the present study determined that the C-terminal region of the VDR is responsible for the action of CN. Taken together, the present findings demonstrated that CN induced osteogenic differentiation of MSCs by activating VDR. The present study explored the regulation of stem cells by using a series of similar steroids and provided evidence to support a potential strategy for the screening of novel drugs to treat bone disease in the future.

[Gut microbiota and osteoporosis].

OBJECTIVE: The rapidly evolving aging society in China is associated with increased incidences of osteoporosis and fractures, which have become common health problems that threaten the quality of life of the elderly. Gut microbiota colonizing in the human intestinal tract form a mutual symbiotic relationship with the host and play an important role in the metabolism and immune regulation of the host. In recent years increasing studies have demonstrated that gut microbiota not only affect the digestive system but also contribute to the disease conditions involving the immune system, and have a close relationship with the occurrence and progression of osteoporosis. This review summarizes the progress and hotspots in recent researches of the associations among gut microbiota, the immune system, osteoporosis.

MicroRNA-574 is involved in cognitive impairment in 5-month-old APP/PS1 mice through regulation of neuritin.

Alzheimer's disease (AD) is the most common form of dementia in the elderly. The recent evidence in AD research suggests that alterations in the microRNA (miRNA) could contribute to risk for the disease. However, little is understood about the roles of miRNAs in cognitive impairment of early Alzheimer's disease (AD). Here, we used 5-month-old APP/PS1 mice, which mimic many of the salient features of the early stage of AD pathological process, to further investigate the roles of miRNAs in synaptic loss involved in learning and memory. We used miRNA expression microarrays on RNA extracted from the hippocampus of 5-month-old APP/PS1 mice and wild type mice. Real-time reverse transcription PCR was conducted to verify the candidate miRNAs discovered by microarray analysis. The data showed that miR-574 was increased significantly in the hippocampus of 5-month-old APP/PS1 mice, which were concomitant with that APP/PS1 mice at the same age displayed a significant synaptic loss and cognitive deficits. Bioinformatic analysis predicted that neuritin (Nrn1) mRNA is targeted by miR-574. Overexpression of miR-574 lowers the levels of neuritin and synaptic proteins expression in primary hippocampal neurons damage induced by Aß25-35. And the expression of miR-574 was also up-regulated in the hippocampal neurons from APP/PS1 mice compared with WT littermates. In contrast, suppression of miR-574 by miR-574 inhibitor significantly results in higher levels of neuritin and synaptic proteins expression. Taken together, miR-574 is involved in cognitive impairment in 5-month-old APP/PS1 mice through regulation of neuritin.

Autocrine BMP4 signaling involves effect of cholesterol myristate on proliferation of mesenchymal stem cells.

We recently identified that cholesterol myristate in traditional Chinese medicine (TCM) is the active compound that increases proliferation of mesenchymal stem cell (MSCs). The present study is further to determine what signal pathway involves in effect of cholesterol myristate. Reverse transcription-PCR, Western blot and ELISA analysis show that cholesterol myristate increases the release of bone morphogenetic protein 4 (BMP4) from MSCs and the expression in the intracellular levels of BMP4 in a time- and dose dependent manner. However, structurally related steroids such as cholesterol and cholesten presented in TCM, both lack of the myristate, did not affect the secretion and expression of BMP4 on MSCs. These finds suggest that myristate is essential for the effects of cholesterol myristate. Furthermore, cholesterol myristate significantly increase BMPRIB levels of MSCs and the number of BMPRIB positive cells in a time- and dose dependent manner, but not BMPR IA or BMPR II. Our results indicate that action of cholesterol myristate may activate the BMP4-BMPRIB autocrine. Moreover, a blocking antibody against BMP4 or the BMP4 antagonist, noggin, partially reduced the effects of cholesterol myristate on MSCs proliferation. Thus, this study is to provide evidence that autocrine BMP4 signaling involves effect of cholesterol myristate on MSCs proliferation.