AIM To determine the efficacy of rifaximin for hepatic encephalopathy(HE) with the linkage of gut microbiome in decompensated cirrhotic patients.METHODS Twenty patients(12 men and 8 women; median ...age, 66.8 years; range, 46-81 years) with decompensated cirrhosis(Child-pugh score > 7) underwent cognitive neuropsychological testing, endotoxin analysis, and fecal microbiome assessment at baseline and after 4 wk of treatment with rifaximin 400 mg thrice a day. HE was determined by serum ammonia level and number connection test(NCT)-A. Changes in whole blood endotoxin activity(EA) was analyzed by endotoxinactivity assay. Fecal microbiome was assessed by 16 S ribosome RNA(rR NA) gene sequencing.RESULTS Treatment with rifaximin for 4 wk improved hyperammonemia(from 90.6 ± 23.9 μg/d L to 73.1 ± 33.1 μg/dL; P < 0.05) and time required for NCT(from 68.2 ± 17.4 s to 54.9 ± 20.3 s; P < 0.05) in patients who had higher levels at baseline. Endotoxin activity was reduced(from 0.43 ± 0.03 to 0.32 ± 0.09; P < 0.05) in direct correlation with decrease in serum ammonia levels(r = 0.5886, P < 0.05). No statistically significant differences were observed in the diversity estimator(Shannon diversity index) and major components of the gut microbiome between the baseline and after treatment groups(3.948 ± 0.548 at baseline vs 3.980 ± 0.968 after treatment; P = 0.544), but the relative abundances of genus Veillonella and Streptococcus were lowered.CONCLUSION Rifaximin significantly improved cognition and reduced endotoxin activity without significantly affecting the composition of the gut microbiome in patients with decompensated cirrhosis.
Sodium‐glucose cotransporter 2 inhibitors (SGLT2‐Is) comprise a new class of antidiabetic agents that inhibit glucose reabsorption in the renal proximal tubules. Although a recent report demonstrated ...the potential ability of SGLT2‐Is to attenuate cancer growth of SGLT2‐expressing cancer cells, little is known about the effects of SGLT2‐Is on hepatocellular carcinoma (HCC). Here, we investigate the anti‐cancer properties of a SGLT2‐I, canagliflozin, against human liver cancer cells. SGTL2 mRNA and protein expression were detected in Huh7 and HepG2 cells, although not in HLE as well as primary human hepatocytes and hepatic stellate cells. Canagliflozin exerted antiproliferative effects on SGLT2‐expressing Huh7 and HepG2 cells in a dose‐dependent manner by inhibiting glycolytic metabolism including glucose uptake, lactate and intracellular ATP production. This agent also induced G2/M arrest and apoptosis with inhibited phosphorylation of ERK, p38 and AKT and cleavage of caspase3. Xenograft tumor growth assay showed that oral administration of canagliflozin (10 mg/kg/day) significantly reduced subcutaneous tumor burdens in a glycemic status‐independent manner, and attenuated intratumor vascularization in Huh7‐ and HepG2‐derived xenograft tumors in BALB/c nude mice. In vitro, canagliflozin suppressed the increased human umbilical vein endothelial cell (HUVEC) proliferation and tubular formation which were observed in Huh7 or HepG2 co‐cultures. By contrast, canagliflozin had no effect on tumor growth and intratumor angiogenesis in SGLT2‐null HLE‐derived xenograft models. These results indicate that SGLT2‐I therapy is a potential new strategy for the treatment of HCC.
What's new?
Sodium‐glucose cotransporter 2 inhibitors (SGLT2‐Is) comprise a new class of antidiabetic agents that inhibit glucose reabsorption in the renal proximal tubules. Although recent evidence suggests that SGLT2‐Is can attenuate growth of SGLT2‐expressing cancer cells, little is known about their effects on hepatocellular carcinoma (HCC). Our study shows that the SGLT2‐I canagliflozin directly inhibits the growth of SGLT2‐expressing liver cancers by reducing glucose uptake and inhibiting glycolytic metabolism. Furthermore, canagliflozin attenuates proangiogenic activity in SGLT2‐expressing liver cancers. Because SGLT2‐Is are already used extensively without serious side effects, these agents may emerge as a new therapeutic strategy for HCC patients.
Hepatic progenitor cells (HPCs) are thought to reside in the canals of Hering and can be activated and contribute to liver regeneration in response to liver injury by proliferating and ...differentiating towards both hepatocytes and biliary epithelial cells. In this setting, several cytokines, chemokines, and growth factors related to liver inflammation and other liver cells comprising the HPC niche, namely hepatic stellate cells (HSCs), play crucial roles in HPC activation and differentiation. In response to several types of liver injury, tumor necrosis factor‐like weak inducer of apoptosis (TWEAK) is secreted by several inflammatory cells, including monocytes, T lymphocytes, and macrophages, and acts as an initiator of the HPC niche and HSC activation. Following TWEAK‐induced activation of the HPC niche, fibroblast growth factor 7 and hepatocyte growth factor released from activated HSC play central roles in maintaining HPC proliferation. In contrast, HGF‐MET and Wnt3a‐β‐catenin signals are the predominant mediators of the hepatocyte differentiation of HPC, whereas epidermal growth factor receptor–NOTCH signaling controls HPC differentiation towards biliary epithelial cells. These signals are maintained exclusively by activated HSC and inflammatory cells surrounding HPC. Together, HSC and inflammatory cells surrounding HPC are responsible for the precise control of HPC proliferation and differentiation fate. In this review, we discuss recent progress in understanding of interactions between HPC and other liver cells in HPC‐mediated liver regeneration in the setting of liver inflammation.
Aims
The efficacy of the vasopressin V2 receptor antagonist tolvaptan for difficult‐to‐treat cirrhotic ascites has recently been reported. However, its effect is variable among patients. This study ...aimed to clarify the predictive factors for obtaining a good response to tolvaptan in patients with difficult‐to‐treat ascites.
Methods
Data were collected from 50 patients with liver cirrhosis having ascites (hepatitis B, n = 1; hepatitis C, n = 22; alcoholism, n = 11; and others, n = 16) after treatment with tolvaptan (3.75–7.5 mg/day) in addition to conventional diuretics. A follow‐up assessment was carried out after 7‐day tolvaptan treatment for all patients.
Results
After an uneventful 7‐day tolvaptan treatment, 18 patients (36.0%) lost more than 2 kg of their body weight (responders). Twenty‐six patients (52.0%) showed an increase in urine volume (>300 mL) on day 2. Tolvaptan was also effective for patients with pleural effusion, portal vein thrombosis, and hepatocellular carcinoma. Basal blood urea nitrogen (BUN) levels, plasma renin activity, and aldosterone levels were significantly higher in the poor responders (<2 kg weight loss), who were considered to be in the relative vascular underfilling state, than in the responders. Basal BUN was extracted as a predictive factor of responsiveness by multivariate logistic regression analysis.
Conclusions
Tolvaptan is useful and safe for the treatment of cirrhotic ascites. This report showed that BUN will predict the response of tolvaptan even when measured before tolvaptan treatment.
Recent studies have suggested that an alteration in the gut microbiota and their products, particularly endotoxins derived from Gram-negative bacteria, may play a major role in the pathogenesis of ...liver diseases. Gut dysbiosis caused by a high-fat diet and alcohol consumption induces increased intestinal permeability, which means higher translocation of bacteria and their products and components, including endotoxins, the so-called “leaky gut”. Clinical studies have found that plasma endotoxin levels are elevated in patients with chronic liver diseases, including alcoholic liver disease and nonalcoholic liver disease. A decrease in commensal nonpathogenic bacteria including Ruminococaceae and Lactobacillus and an overgrowth of pathogenic bacteria such as Bacteroidaceae and Enterobacteriaceae are observed in cirrhotic patients. The decreased diversity of the gut microbiota in cirrhotic patients before liver transplantation is also related to a higher incidence of post-transplant infections and cognitive impairment. The exposure to endotoxins activates macrophages via Toll-like receptor 4 (TLR4), leading to a greater production of proinflammatory cytokines and chemokines including tumor necrosis factor-alpha, interleukin (IL)-6, and IL-8, which play key roles in the progression of liver diseases. TLR4 is a major receptor activated by the binding of endotoxins in macrophages, and its downstream signal induces proinflammatory cytokines. The expression of TLR4 is also observed in nonimmune cells in the liver, such as hepatic stellate cells, which play a crucial role in the progression of liver fibrosis that develops into hepatocarcinogenesis, suggesting the importance of the interaction between endotoxemia and TLR4 signaling as a target for preventing liver disease progression. In this review, we summarize the findings for the role of gut-derived endotoxemia underlying the progression of liver pathogenesis.
Background
Dipeptidyl peptidase-4 inhibitor (DPP4-I) is clinically used as a new oral antidiabetic agent. Although DPP4 is reportedly associated with the progression of chronic liver diseases, the ...effect of DPP4-I on liver fibrosis development is still obscure. This study was designed to elucidate the effect of DPP4-I on liver fibrosis development in conjunction with the activated hepatic stellate cells (Ac-HSCs).
Methods
The antifibrotic effect of DPP4-I was assessed in vivo and in vitro using porcine serum-induced experimental liver fibrosis model. DPP4-I, sitagliptin, at a clinically comparable low dose was administered by gavage daily.
Results
DPP4-I significantly attenuated liver fibrosis development along with the suppression of hepatic transforming growth factor (TGF)-β1, total collagen, and tissue inhibitor of metalloproteinases-1 in a dose-dependent manner. These suppressive effects occurred almost concurrently with the attenuation of HSCs activation. Our in vitro studies showed that DPP4-I inhibited platelet-derived growth factor-BB-mediated proliferation of the Ac-HSCs as well as upregulation of TGF-β1 and α1(I)-procollagen at magnitudes similar to those of the in vivo studies. The inhibitory effects of DPP4-I against HSCs proliferation and fibrogenic gene expression are mediated through the inhibition of the phosphorylation of ERK1/2, p38 and Smad2/3, respectively.
Conclusions
DPP4-I markedly inhibits liver fibrosis development in rats via suppression of HSCs proliferation and collagen synthesis. These suppressive effects are associated with dephosphorylation of ERK1/2, p38 and Smad2/3 in the HSCs. Since DPP4-I is widely used in clinical practice, this drug may represent a potential new therapeutic strategy against liver fibrosis in the near future.
Although gut-derived lipopolysaccharide (LPS) affects the progression of non-alcoholic steatohepatitis (NASH) pathogenesis, few studies have focused on this relationship to develop treatments for ...NASH.
To explore the effects of combination with rifaximin and lubiprostone on NASH liver fibrosis through the modulation of gut barrier function.
To induce steatohepatitis, F344 rats were fed a choline-deficient l-amino acid-defined (CDAA) diet for 12 weeks and received oral administration of rifaximin and/or lubiprostone. Histological, molecular, and fecal microbial analyses were performed. Barrier function in Caco-2 cells were assessed by in vitro assays.
Combination rifaximin/lubiprostone treatment significantly suppressed macrophage expansion, proinflammatory responses, and liver fibrosis in CDAA-fed rats by blocking hepatic translocation of LPS and activation of toll-like receptor 4 signaling. Rifaximin and lubiprostone improved intestinal permeability via restoring tight junction proteins (TJPs) with the intestinal activation of pregnane X receptor and chloride channel-2, respectively. Moreover, this combination increased the abundance of Bacteroides, Lactobacillus, and Faecalibacterium as well as decreased that of Veillonella resulting in an increase of fecal short-chain fatty acids and a decrease of intestinal sialidase activity. Both agents also directly suppressed the LPS-induced barrier dysfunction and depletion of TJPs in Caco-2 cells.
The combination of rifaximin and lubiprostone may provide a novel strategy for treating NASH-related fibrosis.
Lipopolysaccharides (LPSs) have been reported to be important factors in promoting the progression of hepatocellular carcinoma (HCC), but the corresponding molecular mechanisms remain to be ...elucidated. We hypothesize that epiregulin (EREG), an epidermal growth factor (EGF) family member derived from hepatic stellate cells (HSCs) and activated by LPS stimulation, is a crucial mediator of HCC progression with epidermal growth factor receptor (EGFR) expression in the tumor microenvironment. We used a mouse xenograft model of Huh7 cells mixed with half the number of LX-2 cells, with/without intraperitoneal LPS injection, to elucidate the role of EREG in LPS-induced HCC. In the mouse model, LPS administration significantly enlarged the size of xenografted tumors and elevated the expression of EREG in tumor tissues compared with those in negative controls. Moreover, CD34 immunostaining and the gene expressions of angiogenic markers by a reverse transcription polymerase chain reaction revealed higher vascularization, with increased interleukin-8 (IL-8) expression in the tumors of the mice group treated with LPS compared to those without LPS. Our data collectively suggested that EREG plays an important role in the cancer microenvironment under the influence of LPS to increase not only the tumor cell growth and migration/invasion of EGFR-positive HCC cells but also tumor neovascularization via IL-8 signaling.
Cholangiocarcinoma (CCA) is associated with high mortality rates because of its resistance to conventional gemcitabine-based chemotherapy. Hydroxy-methyl-glutaryl-coenzyme A reductase inhibitors ...(statins) reportedly exert anti-cancer effects in CCA and lower the risk of CCA; however, the underlying mechanism of these effects remains unclear. The proliferative and oncogenic activities of the transcriptional co-activator Yes-associated protein (YAP) are driven by its association with the TEA domain (TEAD) of transcription factors; thereby, upregulating genes that promote cell growth, inhibit apoptosis, and confer chemoresistance. This study investigated the effects of atorvastatin in combination with gemcitabine on the progression of human CCA associated with YAP oncogenic regulation. Both atorvastatin and gemcitabine concentration-dependently suppressed the proliferation of HuCCT-1 and KKU-M213 human CCA cells. Moreover, both agents induced cellular apoptosis by upregulating the pro-apoptotic marker
and downregulating the anti-apoptotic markers
and
. Atorvastatin also significantly decreased the mRNA expression of the TEAD target genes
,
,
, and
in both CCA cell lines. A xenograft tumor growth assay indicated that atorvastatin and gemcitabine potently repressed human CCA cell-derived subcutaneous tumor growth by inhibiting YAP nuclear translocation and TEAD transcriptional activation. Notably, the anti-cancer effects of the individual agents were significantly enhanced in combination. These results indicate that gemcitabine plus atorvastatin could serve as a potential novel treatment option for CCA.
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