Gut Microbiota Deficiency Exacerbates Liver Injury in Bile Duct Ligated Mice via Inflammation and Lipid Metabolism.

Bile components play a critical role in maintaining gut microbiota homeostasis. In cholestasis, bile secretion is impaired, leading to liver injury. However, it remains to be elucidated whether gut microbiota plays a role in cholestatic liver injury. Here, we performed a sham operation and bile duct ligation (BDL) in antibiotic-induced microbiome depleted (AIMD) mice and assessed liver injury and fecal microbiota composition in these mice. Significant reductions in gut microbiota richness and diversity were found in AIMD-sham mice when compared to sham controls. Three-day BDL leads to great elevation of plasma ALT, ALP, total bile acids, and bilirubin where reduced diversity of the gut microbiota was also found. AIMD further aggravated cholestatic liver injury evidenced by significantly higher levels of plasma ALT and ALP, associated with further reduced diversity and increased Gram-negative bacteria in gut microbiota. Further analyses revealed increased levels of LPS in the plasma of AIMD-BDL mice where elevated expression of inflammatory genes and decreased expression of hepatic detoxification enzymes were also found in liver when compared to the BDL group. These findings indicate that gut microbiota plays a critical role in cholestatic liver injury. Maintaining its homeostasis may alleviate liver injury in patients with cholestasis.

Solute Carrier Organic Anion Transporter Family Member 3A1 Is a Bile Acid Efflux Transporter in Cholestasis.

BACKGROUND & AIMS: Bile acid transporters maintain bile acid homeostasis. Little is known about the functions of some transporters in cholestasis or their regulatory mechanism. We investigated the hepatic expression of solute carrier organic anion transporter family member 3A1 (SLCO3A1, also called OATP3A1) and assessed its functions during development of cholestasis. METHODS: We measured levels of OATP3A1 protein and messenger RNA and localized the protein in liver tissues from 22 patients with cholestasis and 21 patients without cholestasis, using real-time quantitative polymerase chain reaction, immunoblot, and immunofluorescence analyses. We performed experiments with Slco3a1-knockout and C57BL/6J (control) mice. Mice and Sprague-Dawley rats underwent bile duct ligation (BDL) or a sham operation. Some mice were placed on a 1% cholic acid (CA) diet to induce cholestasis or on a control diet. Serum and liver tissues were collected and analyzed; hepatic levels of bile acids and 7-α-C4 were measured using liquid chromatography/mass spectrometry. Human primary hepatocytes and hepatoma (PLC/PRF/5) cell lines were used to study mechanisms that regulate OATP3A1 expression and transport. RESULTS: Hepatic levels of OATP3A1 messenger RNA and protein were significantly increased in liver tissues from patients with cholestasis and from rodents with BDL or 1% CA diet-induced cholestasis. Levels of fibroblast growth factor 19 (FGF19, FGF15 in rodents) were also increased in liver tissues from patients and rodents with cholestasis. FGF19 signaling activated the Sp1 transcription factor and nuclear factor κB to increase expression of OATP3A1 in hepatocytes; we found binding sites for these factors in the SLCO3A1 promoter. Slco3a1-knockout mice had shorter survival times and increased hepatic levels of bile acid, and they developed more liver injury after the 1% CA diet or BDL than control mice. In hepatoma cell lines, we found OATP3A1 to take prostaglandin E2 and thyroxine into cells and efflux bile acids. CONCLUSIONS: We found levels of OATP3A1 to be increased in cholestatic liver tissues from patients and rodents compared with healthy liver tissues. We show that OATP3A1 functions as a bile acid efflux transporter that is up-regulated as an adaptive response to cholestasis.

A homozygous R148W mutation in Semaphorin 7A causes progressive familial intrahepatic cholestasis.

Semaphorin 7A (SEMA7A) is a membrane-bound protein that involves axon growth and other biological processes. SEMA7A mutations are associated with vertebral fracture and Kallmann syndrome. Here, we report a case with a mutation in SEMA7A that displays familial cholestasis. WGS reveals a SEMA7AR148W homozygous mutation in a female child with elevated levels of serum ALT, AST, and total bile acid (TBA) of unknown etiology. This patient also carried a SLC10A1S267F allele, but Slc10a1S267F homozygous mice exhibited normal liver function. Similar to the child, Sema7aR145W homozygous mice displayed elevated levels of serum ALT, AST, and TBA. Remarkably, liver histology and LC-MS/MS analyses exhibited hepatocyte hydropic degeneration and increased liver bile acid (BA) levels in Sema7aR145W homozygous mice. Further mechanistic studies demonstrated that Sema7aR145W mutation reduced the expression of canalicular membrane BA transporters, bile salt export pump (Bsep), and multidrug resistance-associated protein-2 (Mrp2), causing intrahepatic cholestasis in mice. Administration with ursodeoxycholic acid and a dietary supplement glutathione improved liver function in the child. Therefore, Sema7aR145W homozygous mutation causes intrahepatic cholestasis by reducing hepatic Bsep and Mrp2 expression.

The role of neutrophil to lymphocyte ratio for the assessment of liver fibrosis and cirrhosis: a systematic review.

INTRODUCTION: Neutrophil to lymphocyte ratio (NLR) is widely used to assess inflammatory diseases. We performed a systematic review to explore the prognostic role of NLR for the assessment of liver fibrosis and cirrhosis. Areas covered: We searched the PubMed and EMBASE databases for the eligible papers which explored the association between NLR and liver fibrosis/cirrhosis or investigated the prognostic value of NLR in cirrhotic patients. Expert commentary: In accordance with assessment of liver fibrosis stage, we classified papers into four subgroups by etiology. For the patients with nonalcoholic fatty liver disease (NAFLD) there was a significant association between NLR and fibrosis stage and nonalcoholic fatty liver disease activity score (NAS), while NLR had a negative correlation with fibrosis stage for the patients with chronic hepatitis B (CHB). As for the patients with and chronic hepatitis C (CHC), NLR might not be significantly associated with fibrosis stage. Moreover, NLR seemed to be significantly useful for predicting outcomes in cirrhotic patients. Hence, NLR might be associated with liver fibrosis stage, especially in patients with NAFLD. Furthermore, NLR might be a useful biomarker for evaluating the prognosis in cirrhotic patients.

Evaluation of the diagnostic potential of ex vivo Raman spectroscopy in gastric cancers: fingerprint versus high wavenumber.

The aim of this study was to apply Raman spectroscopy in the high wavenumber (HW) region (2800 to 3000??cm?1) for ex vivo detection of gastric cancer and compare its diagnostic potential with that of the fingerprint (FP) region (800 to 1800??cm?1). Raman spectra were collected in the FP and HW regions to differentiate between normal mucosa (n=38) and gastric cancer (n=37). The distinctive Raman spectral differences between normal and cancer tissues are observed at 853, 879, 1157, 1319, 1338, 1448, and 2932??cm?1 and are primarily related to proteins, lipids, nucleic acids, collagen, and carotenoids in the tissue. In FP and HW Raman spectroscopy for diagnosis of gastric cancer, multivariate diagnostic algorithms based on partial-least-squares discriminant analysis, together with leave-one-sample-out cross validation, yielded diagnostic sensitivities of 94.59% and 81.08%, and specificities of 86.84% and 71.05%, respectively. Receiver operating characteristic analysis further confirmed that the FP region model performance is superior to that of the HW region model. Better differentiation between normal and gastric cancer tissues can be achieved using FP Raman spectroscopy and PLS-DA techniques, but the complementary natures of the FP and HW regions make both of them useful in diagnosis of gastric cancer.

Raman spectroscopy analysis of the biochemical characteristics of molecules associated with the malignant transformation of gastric mucosa.

OBJECTIVE: The purpose of this study was to comparatively analyze the signature Raman spectra of genomic DNA, nuclei, and tissue of normal gastric mucosa and gastric cancer and to investigate the biochemical transformation of molecules associated with gastric mucosa malignancy. METHOD: Genomic DNA, nuclei, and tissue from normal gastric mucosa and gastric cancer were analyzed by Raman spectroscopy. RESULTS: 1) The Raman spectrum of gastric cancer genomic DNA showed that two peaks appeared, one at approximately 1090 cm-1 with a higher intensity than the peak at 1050 cm-1 in the spectrum. Characteristic peaks appeared at 950 cm-1, 1010 cm-1, and 1100-1600 cm-1. 2) Using a hematoxylin and eosin (H&E)-stained section, the intensity of the characteristic peak of nucleic acids at 1085 cm-1 was increased and shifted to 1088 cm-1 in cancer cells. The relative intensity of the characteristic peaks of nucleoproteins at 755 cm-1 and 1607 cm-1 was significantly increased in cancer cells compared with normal cells. 3) Compared with normal tissues, the peak representing PO2- symmetric stretching vibration shifted from 1088 cm-1 to 1083 cm-1 in cancer tissue, and the characteristic peak for collagen at 938 cm-1 shifted to 944 cm-1. In addition, an extra characteristic peak indicating C = C stretching vibration appeared at 1379 cm-1 in the lipid spectrum in cancer tissue. CONCLUSIONS: The position, intensity, and shape of peaks in the Raman spectra of DNA, nuclei, and tissue from gastric cancer were significantly different compared with those of normal cells. These results indicate that the DNA phosphate backbone becomes unstable in cancer cells and might be broken; the relative content of histones is increased and stable; the relative collagen content is reduced, facilitating cancer cell metastasis; and the relative content of unsaturated fatty acids is increased, increasing the mobility of the plasma membrane of cancer cells.