Project description:Increased intestinal permeability is associated to the onset of inflammatory bowel disease (IBD) since the exposition to luminal content causes an immunological response that promotes intestinal inflammation. Several studies have been shown that microRNAs (miRNAs) are involved in IBD pathogenesis. Here, we aimed to functionally characterize the role of miRNAs in the regulation of intestinal permeability. miRNA profile of intestinal epithelial cells (IECs) isolated by colon of a UC mice model were identified using microarray. To predict the target genes of modulated miRNAs, we performed a bioinformatic analysis. To validate biologically miRNA targets, we performed transient transfection experiments in HT-29, Caco2 and T84 cell lines. To assess their role in barrier function, trans-epithelial electrical resistance and dextran flux assays were used. To investigate the in vivo effect of miR-195-5p, we employed a DSS-induced colitis model in mice. We identified 18 deregulated miRNAs in IECs from UC mice model and control mice. Among them, down-regulated miR-195-5p targeted CLDN2 and are involved in altered intestinal permeability. CLDN2 expression levels were increased in UC mice models and negatively correlated with the miR-195-5p expression. We demonstrated that the gain-of-function of miR-195-5p in colonic epithelial cell lines decreased the CLDN2 levels. We in vitro confirmed that miR-195-5p was able to control the intestinal barrier integrity. We also in vivo demonstrated that miR-195-5p attenuated the colonic inflammatory response in DSS-induced colitis and reduced the colonic permeability. All together our data support a previously unreported role of miR-195-5p in intestinal permeability and provide a potential pharmacological target for new therapeutic approaches in IBD.
Project description:Lung cancer is an intrinsically highly metastatic disease and the leading cause of cancer-related deaths worldwide. Although discovery of molecular aberrations in lung adenocarcinomas has led to development of effective targeted therapies, corresponding “drivers” in lung squamous carcinomas (LUSC) have not materialized. Extensive molecular profiling has revealed LUSC tumors have non-recurrent somatic mutations and are largely driven by copy number alterations. Because microRNAs (miRs) play increasingly important roles in regulating metastasis-relevant pathways, we evaluated whether miRs can regulate LUSC progression. By integrating bioinformatics of the Cancer Genome Atlas (TCGA) with novel, highly metastatic LUSC models, we found that miR-671-5p is a key inhibitor of LUSC metastasis. Surprisingly, miR-671-5p regulates LUSC metastasis by inhibiting a circular RNA (circRNA), CDR1as. Although the putative function of CDR1as is through miR-7 sponging, we found miR-671-5p more potently silences an axis of CDR1as and its anti-sense transcript, cerebellar degeneration related antigen 1 (CDR1). To our knowledge, no function of CDR1 has ever been described. We found loss of CDR1as and CDR1 significantly inhibited LUSC metastases. Intriguingly, CDR1 was strongly associated with an epithelial-mesenchymal transition (EMT) program in LUSC tumors, and was sufficient to promote metastases, increased migration and substrate-independent survival, known as anoikis-resistance. CDR1, which directly interacts with AP1 and COPI subunits, no longer promoted migration and anoikis-resistance upon blockade of Golgi trafficking. Our findings reveal a miR/circRNA axis that regulates LUSC metastases through an enigmatic protein, CDR1.
Project description:Objective: The protective components ACE2/Ang(1-7)/MasR of the renin-angiotensin system has been verified to play a role in Alzheimer's disease (AD). Our previous study revealed that enhancement of brain ACE2 activity, an important effector of RAS, by diminazene aceturate (DIZE) ameliorated Alzheimer's disease-like neuropathology and attenuated neuroinflammation in the brain of SAMP8 mice. However, the potential molecular mechanisms by which DIZE modulates neuroinflammation in AD remain unclear. Materials and Methods: APP/PS1 mice were injected intraperitoneally with DIZE (once a day for 30 consecutive days). Cognitive functions, neuronal and synaptic integrity, and inflammation-related markers were assessed by Morris water maze, Nissl staining, Western blot and ELISA, respectively. Since astrocytes played a crucial role in AD-related neuroinflammation whilst miRNAs were reported to participate in modulating inflammatory responses, astrocytes of APP/PS1 mice were then isolated for high-throughput miRNAs sequencing to identify the most differentially expressed miRNA following DIZE treatment. Afterward, the downstream pathway of this miRNA in the anti-inflammatory action of DIZE was investigated using primary astrocytes. Results: The results showed that DIZE alleviated cognitive impairment and neuronal and synaptic damage in APP/PS1 mice. Simultaneously, DIZE suppressed the secretion of pro-inflammatory cytokines and the expression of NLRP3 inflammasome. Importantly, miR-224-5p was significantly up-regulated in the astrocytes of APP/PS1 mice treated by DIZE, and NLRP3 is one of the targets of miR-224-5p. Upregulation of miR-224-5p inhibited the expression of NLRP3 in Aβ1–42-stimulated cells, whereas miR-224-5p downregulation reversed this effect. Furthermore, the inhibition of miR-224-5p could reverse the inhibitory effect of DIZE on astrocytic NLRP3 inflammasome. Conclusion: These results firstly suggested that DIZE inhibits astrocyte-mediated neuroinflammation via miR-224-5p/NLRP3 pathway. Moreover, these results reveal the underlying mechanisms by which DIZE inhibits neuroinflammation under AD condition and uncovers the potential of DIZE in AD treatment.
Project description:Ulcerative Colitis is an autoimmune inflammatory bowel disease that causes chronic inflammation in the colon and the rectum. Althoung extensively researched, the underlying molecular mechanisms of Ulcerative Colitis remain elusive. Especially, there is a lack of understanding about regulatory non-coding miRNA expression during Ulcerative Colitis in a cell type-specific context. Therefore, we performed high-throughput miRNA profiling of Fluorescence Activated Cell Sorting (FACS)-enriched CD66a+ and CD44+ colonic epithelial cell populations from colon tissue biopsies of 16 patients with active Ulcerative Colitis, 15 patients with quiescent Ulcerative Colitis and 17 Symptomatic Control individuals.
Project description:In this study, we used miRNA sequencing to analyze and identify possible miRNAs that can be regulated by and UBE2CP3 in gastric cancer. The results showed that lncRNA UBE2CP3 overexpression decreased the expression of miR-138-5p. Due to miR-138-5p was able to target ITGA2 expression, and UBE2CP3 knockdown significantly downregulates ITGA2 expression, we speculated UBE2CP3 may positively regulate ITGA2 expression through sponging miR-138-5p in GC.
Project description:Background/ Aim: Diabetes has substantive co-occurrence with disorders of gut-brain interactions (DGBIs). The pathophysiological and molecular mechanisms linking diabetes and DGBIs are unclear. miRNAs are key regulators of diabetes and gut dysmotility. We investigated whether impaired gut barrier function regulated by a key miRNA, miR-10b-5p, links diabetes and gut dysmotility. Methods: We created a new mouse line using the Mb3Cas12a/Mb3Cpf1 endonuclease to knock out mir-10b globally. Loss of function studies were conducted to characterize diabetes, gut dysmotility, and gut barrier dysfunction phenotypes in these mice. Gain of function studies were conducted by injecting these mice with a miR-10b-5p mimic. Further, we performed miRNA-sequencing analysis from colonic mucosa from mir-10b KO, WT, and miR-10b-5p mimic injected mice to confirm 1) deficiency of miR-10b-5p in KO mice, and 2) restoration of miR-10b-5p expression after the mimic injection. Results: Congenital loss of mir-10b in mice led to the development of hyperglycemia, gut dysmotility, and gut barrier dysfunction. We found increased gut permeability and reduced expression of the tight junction protein Zonula occludens-1 (ZO-1), in the colon of mir-10b KO mice. We further confirmed that patients with diabetes or IBS-C, a known DGBI that is linked to leaky gut, had significantly reduced miR-10b-5p expression. Injection of a miR-10b-5p mimic in mir-10b KO mice rescued these molecular alterations and phenotypes. Conclusion: Our study uncovered a potential pathophysiologic mechanism of gut barrier dysfunction that links both the diabetes and gut dysmotility phenotypes in mice lacking miR-10b-5p. Treatment with a miR-10b-5p mimic reversed the leaky gut, diabetic, and gut dysmotility phenotypes, highlighting the translational potential of miR-10b-5p mimic.
Project description:Background: Retinal pigment epithelium (RPE) is the major site of pathological alterations in AMD, yet the mechanism governing its degeneration is poorly understood. Results: We found that expression of circSPECC1, a circular RNA derived from the SPECC1 gene, was down-regulated in RPE treated with oxidative stress and inflammation. CircSPECC1 insufficiency elevated mitochondrial superoxide in RPE, leading to oxidative stress induced RPE ferroptosis and depolarization. CircSPECC1 silencing also interfered RPE metabolism, causing irregular lipid metabolism and lipid accumulation. In mice, circSPECC1 deficiency leads to decreased visual ability, atrophic fundus presentations, as well as structural anomalies and reduced epithelial integrity in RPE. Moreover, retinal homeostasis was messed up upon circSPECC1 loss, as shown by photoreceptor dysfunction and microglia activation. Mechanically, decreased circSPECC1 expression in dysfunctional RPE was due to reduced N6-methyladenosine (m6A) levels of circSPECC1 transcript, which interrupted its back-splicing and circularization depending on m6A reader YTHDC1. CircSPECC1 regulated RPE features via directly sponging miR-145-5p to block its interaction with CDKN1A. Overexpressing miR-145-5p aggravated RPE dysfunctions in vivo and in vitro, mimicking effects of circSPECC1 silencing. Additionally, miR-145-5p inhibition alleviated RPE anomalies induced by circSPECC1 insufficiency, while miR-145-5p overexpression aggravated the retinal phenotypes. Conclusions: Collectively, circSPECC1, mediated by m6A modification and sponges miR-145-5p, resists oxidative stress injuries and maintains lipid metabolism in RPE. Pharmacological supplementation of circSPECC1, miR-145-5p inhibitor or m6A regulator is promising therapeutic option for atrophic retinopathies.
Project description:BACKGROUND: Ulcerative colitis (UC) is a common chronic inflammatory bowel disease without curative treatment. METHODS: We conducted gene set enrichment analysis to explore potential therapeutic agent for UC. Human colon tissue samples were collected to test H3 acetylation in UC. Both in vivo and in vitro colitis models were constructed to verify the role and mechanism of H3 acetylation modification in UC. Intestine-specific vitamin D receptor (VDR)-/- mice and VD (vitamin D)-deficient diet-fed mice were used to explore downstream molecular mechanism accordingly. RESULTS: According to the Connectivity Map database, MS-275 (class I histone deacetylase inhibitor) was the top-ranked agent, indicating potential importance of histone acetylation in the pathogenesis of UC. We then found that histone H3 acetylation was significantly decreased in the colon epithelium of UC patients and negatively associated with disease severity. MS-275 treatment inhibited histone H3 deacetylation, and subsequently attenuated nuclear factor kappa B (NF-?B)-induced inflammation, reduced cellular apoptosis, maintained epithelial barrier function, and thereby reduced colitis activity in a mouse model of colitis. We also identified VDR to be a downstream effector of MS-275. The curative effect of MS-275 on colitis was abolished in VDR-/- mice and in VD-deficient diet-fed mice and VDR directly targeted p65. In UC patients, histone H3 acetylation, VDR and zonulin-1 expression showed similar downregulation patterns and were negatively associated with disease severity. CONCLUSION: We demonstrate that MS-275 inhibits histone deacetylation and alleviates colitis by ameliorating inflammation, reducing apoptosis and maintaining intestinal epithelial barrier via VDR, providing new strategies for UC treatment.
Project description:The transcriptional signature of mucosa of patients with ulcerative colitis (UC) in remission reveals long-lasting changes in the epithelial barrier which persist once the inflammatory response has resolved. In order to investigate if these changes are caused by primary defects in the epithelial cells, we generated in vitro epithelial organoid cultures (EpOCs) from colon samples of non-IBD controls and UC patients. After induction of differentiation, total RNA was extracted from both EpOCs and differentiated EpOCs (d-EpOCs) and used for hybridization on Affymetrix microarray.