NaB may restore the dysbiosis of gut microbiota to attenuate steatohepatitis, which is suggested to be a potential gut microbiota modulator and therapeutic substance for NAFLD.
Non-alcoholic steatohepatitis (NASH) is an epidemic metabolic disease with limited therapeutic strategies. Cumulative data support the pivotal role of gut microbiota in NASH. Here, we investigated the hypothesis regarding whether fecal microbiota transplantation (FMT) is effective in attenuating high-fat diet (HFD)-induced steatohepatitis in mice. Mice were randomized into control, HFD and HFD + FMT groups. After an 8-week HFD, FMT treatment was initiated and carried out for 8 weeks. The gut microbiota structure, butyrate concentrations of the cecal content, liver pathology and intrahepatic lipid and cytokines were examined. Our results showed that after FMT, the gut microbiota disturbance was corrected in HFD-fed mice with elevated abundances of the beneficial bacteria Christensenellaceae and Lactobacillus. FMT also increased butyrate concentrations of the cecal content and the intestinal tight junction protein ZO-1, resulting in relief of endotoxima in HFD-fed mice. Steatohepatitis was alleviated after FMT, as indicated by a significant decrease in intrahepatic lipid accumulation (reduced Oli-red staining, decreased intrahepatic triglyceride and cholesterol), intrahepatic pro-inflammatory cytokines, and the NAS score. Accordingly, intrahepatic IFN-γ and IL-17 were decreased, but Foxp3, IL-4 and IL-22 were increased after FMT intervention. These data indicate that FMT attenuated HFD-induced steatohepatitis in mice via a beneficial effect on the gut microbiota.
BackgroundTrastuzumab resistance followed by metastasis is a major obstacle for improving the clinical outcome of patients with advanced human epidermal growth factor receptor 2-positive (HER-2+) breast cancer. While long non-coding RNAs (lncRNAs) can modulate cell behavior, the contribution of these RNAs in trastuzumab resistance and metastasis of HER-2+ breast cancer is not well known. In this study, we sought to identify the regulatory role of lncRNA in trastuzumab resistance and accompanied Epithelial-mesenchymal Transition (EMT) process in advanced HER-2+ breast cancer.MethodsTrastuzumab-resistant SKBR-3-TR and BT474-TR cell lines were established by grafting SKBR-3 and BT474 cells into mouse models and subjected to trastuzumab treatment. LncRNA microarray followed by quantitative reverse transcription PCR (qRT-PCR) was carried out to verify the differentially expressed lncRNAs. Western blotting, bioinformatics analysis, immunofluorescence assay and immunoprecipitation assays (ChIP and RIP) were performed to identify the involvement and functional interactions between H3K27 acetylation and terminal differentiation-induced non-coding RNA (TINCR) or between TINCR and its downstream genes including miR-125b, HER-2 and Snail-1. In addition, a series of in vitro and in vivo assays were performed to assess the functions of TINCR.ResultsAn increase in both, IC50 value of trastuzumab and EMT was observed in the established trastuzumab-resistant cell lines. The expression level of TINCR was significantly increased in trastuzumab-resistant cells when compared with sensitive cells. Knockdown of TINCR reversed the trastuzumab resistance and the acquired EMT in these cells. TINCR was detected in the cytoplasm of breast cancer cells and could sponge miR-125b, thereby releasing HER-2 and inducing trastuzumab resistance. In addition, Snail-1 was found to be the target gene of miR-125b and overexpression of Snail-1 could reverse the suppressed migration, invasion, and EMT caused by TINCR silencing. The upregulation of TINCR in breast cancer was attributed to the CREB-binding protein (CBP)-mediated H3K27 acetylation at the promoter region of TINCR. Clinically, HER-2+ breast cancer patients with high TINCR expression levels were associated with poor response to trastuzumab therapy and shorter survival time.ConclusionTINCR could promote trastuzumab resistance and the accompanied EMT process in breast cancer. Therefore, TINCR might be a potential indicator for prognosis and a therapeutic target to enhance the clinical efficacy of trastuzumab treatment.Electronic supplementary materialThe online version of this article (10.1186/s12943-018-0931-9) contains supplementary material, which is available to authorized users.
Background The volume overload of isolated mitral regurgitation (MR) in the dog results in left ventricular (LV) dilatation and interstitial collagen loss. To better understand the mechanism of collagen loss we performed a gene array and overlaid regulated genes into Ingenuity Pathway Analysis (IPA). Methods and Results Gene arrays from LV tissue were compared in 4 dogs prior to and 4 months after MR. Cine-magnetic resonance-derived LV end-diastolic volume increased 2-fold (p=0.005) and LV ejection fraction increased from 41 to 53% (p < 0.001). LV interstitial collagen decreased 40% (p<0.05) compared to controls and replacement collagen was in short strands and in disarray. IPA identified Marfan’s syndrome, aneurysm formation, LV dilatation, and myocardial infarction, all of which have extracellular matrix (ECM) protein defects and/or degradation. MMP-1 and -9 mRNA increased 5- (p=0.01) and 10-fold (0.003), while collagen I did not change and collagen III mRNA increased 1.5-fold (p=0.02). However, noncollagen genes important in ECM structure were significantly downregulated, including decorin, fibulin 1, and fibrillin 1. Decorin mRNA downregulation correlated with LV dilatation (r= 0.83 p<0.05). In addition, connective tissue growth factor and plasminogen activator inhibitor were downregulated, along with multiple genes in TGF-β signaling pathway, resulting decreased LV TGF-β1 activity (p=0.03). Conclusions LV collagen loss in isolated, compensated MR is chiefly due to post-translational processing and degradation. The downregulation of multiple noncollagen genes important in global ECM structure, coupled with decreased expression of multiple profibrotic factors, explain the failure to replace interstitial collagen in the MR heart.
Glucagon-like peptide-1 (GLP-1) has a broad spectrum of biological activity by regulating metabolic processes via both the direct activation of the class B family of G protein-coupled receptors and indirect nonreceptor-mediated pathways. GLP-1 receptor (GLP-1R) agonists have significant therapeutic effects on non-alcoholic fatty liver disease (NAFLD) and steatohepatitis (NASH) in animal models. However, clinical studies indicated that GLP-1 treatment had little effect on hepatic steatosis in some NAFLD patients, suggesting that GLP-1 resistance may occur in these patients. It is well-known that the gut metabolite sodium butyrate (NaB) could promote GLP-1 secretion from intestinal L cells. However, it is unclear whether NaB improves hepatic GLP-1 responsiveness in NAFLD. In the current study, we showed that the serum GLP-1 levels of NAFLD patients were similar to those of normal controls, but hepatic GLP-1R expression was significantly downregulated in NAFLD patients. Similarly, in the NAFLD mouse model, mice fed with a high-fat diet showed reduced hepatic GLP-1R expression, which was reversed by NaB treatment and accompanied by markedly alleviated liver steatosis. In addition, NaB treatment also upregulated the hepatic p-AMPK/p-ACC and insulin receptor/insulin receptor substrate-1 expression levels. Furthermore, NaB-enhanced GLP-1R expression in HepG2 cells by inhibiting histone deacetylase-2 independent of GPR43/GPR109a. These results indicate that NaB is able to prevent the progression of NAFL to NASH via promoting hepatic GLP-1R expression. NaB is a GLP-1 sensitizer and represents a potential therapeutic adjuvant to prevent NAFL progression to NASH.
Left ventricular (LV) volume overload (VO) causes eccentric remodeling with inflammatory cell infiltration and extracellular matrix (ECM) degradation, for which there is currently no proven therapy. To uncover new pathways that connect inflammation and ECM homeostasis with cellular dysfunction, we determined the cardiac transciptome in subacute, compensated, and decompensated stages based on in vivo hemodynamics and echocardiography in the rat with aortocaval fistula (ACF). LV dilatation at 5 wk was associated with a normal LV end-diastolic dimension-to-posterior wall thickness ratio (LVEDD/PWT; compensated), whereas the early 2-wk (subacute) and late 15-wk (decompensated) ACF groups had significant increases in LVEDD/PWT. Subacute and decompensated stages had a significant upregulation of genes related to inflammation, the ECM, the cell cycle, and apoptosis. These changes were accompanied by neutrophil and macrophage infiltration, nonmyocyte apoptosis, and interstitial collagen loss. At 15 wk, there was a 40-fold increase in the matricellular protein periostin, which inhibits connections between collagen and cells, thereby potentially mediating a side-to-side slippage of cardiomyocytes and LV dilatation. The majority of downregulated genes was composed of mitochondrial enzymes whose suppression progressed from 5 to 15 wk concomitant with LV dilatation and systolic heart failure. The profound decrease in gene expression related to fatty acid, amino acid, and glucose metabolism was associated with the downregulation of peroxisome proliferator associated receptor (PPAR)-α-related and bioenergetic-related genes at 15 wk. In VO, an early phase of inflammation subsides at 5 wk but reappears at 15 wk with marked periostin production along with the suppression of genes related to PPAR-α and energy metabolism.
AIMTo assess disease-specific circulating microRNAs (miRNAs) in non-alcoholic steatohepatitis (NASH) patients.METHODSA total of 111 biopsy-proven non-alcoholic fatty liver disease (NAFLD) or chronic hepatitis B (CHB) patients and healthy controls from mainland China were enrolled to measure their serum levels of miR-122, -125b, -146b, -16, -21, -192, -27b and -34a. The correlations between serum miRNAs and histological features of NAFLD were determined. The diagnostic value of miRNA in NASH and significant fibrosis was analyzed and compared with that of cytokeratin-18 (CK-18), fibrosis-4 (FIB-4), and aspartate aminotransferase to platelet ratio index (APRI), respectively.RESULTSCirculating miR-122, -16, -192 and -34a showed differential expression levels between NAFLD and CHB patients, and miR-34a had an approximately 2-fold increase in NAFLD samples compared with that of CHB samples (P < 0.01). Serum miR-122, -192 and -34a levels were correlated with steatosis (R = 0.302, 0.323 and 0.470, respectively, P < 0.05) and inflammatory activity (R = 0.445, 0.447 and 0.517, respectively, P < 0.01); only serum miR-16 levels were associated with fibrosis (R = 0.350, P < 0.05) in patients with NAFLD. The diagnostic value of miR-34a for NASH (area under the receiver operating characteristic, 0.811, 95%CI: 0.670-0.953) was superior to that of alanine aminotransferase, CK-18, FIB-4 and APRI in NAFLD, but miR-16 showed a limited performance in the diagnosis of significant fibrosis in NASH.CONCLUSIONCirculating miR-34a may serve as a disease-specific noninvasive biomarker for the diagnosis of NASH.
BackgroundThe clinical problem of a “pure volume overload” as in isolated mitral or aortic regurgitation currently has no documented medical therapy that attenuates collagen loss and the resultant left ventricular (LV) dilatation and failure. Here, we identify a potential mechanism related to upregulation of the kallikrein-kinin system in the volume overload of aortocaval fistula (ACF) in the rat.Methodology/Principal FindingsLV interstitial fluid (ISF) collection, hemodynamics, and echocardiography were performed in age-matched shams and 4 and 15 wk ACF rats. ACF rats had LV dilatation and a 2-fold increase in LV end-diastolic pressure, along with increases in LV ISF bradykinin, myocardial kallikrein and bradykinin type-2 receptor (BK2R) mRNA expression. Mast cell numbers were increased and interstitial collagen was decreased at 4 and 15 wk ACF, despite increases in LV ACE and chymase activities. Treatment with the kallikrein inhibitor aprotinin preserved interstitial collagen, prevented the increase in mast cells, and improved LV systolic function at 4 wk ACF. To establish a cause and effect between ISF bradykinin and mast cell-mediated collagen loss, direct LV interstitial bradykinin infusion in vivo for 24 hrs produced a 2-fold increase in mast cell numbers and a 30% decrease in interstitial collagen, which were prevented by BK2R antagonist. To further connect myocardial stretch with cellular kallikrein-kinin system upregulation, 24 hrs cyclic stretch of adult cardiomyocytes and fibroblasts produced increased kallikrein, BK2R mRNA expressions, bradykinin protein and gelatinase activity, which were all decreased by the kallikrein inhibitor-aprotinin.Conclusions/SignificanceA pure volume overload is associated with upregulation of the kallikrein-kinin system and ISF bradykinin, which mediates mast cell infiltration, extracellular matrix loss, and LV dysfunction–all of which are improved by kallikrein inhibition. The current investigation provides important new insights into future potential medical therapies for the volume overload of aortic and mitral regurgitation.
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