Biomarkers reflecting pericellular fibrosis improve together with liver histology after bariatric surgery in early non-alcoholic fatty liver disease.

AIM: Non-invasive tests for non-alcoholic fatty liver disease (NAFLD) are needed for assessing disease stage, prognosis and treatment efficacy. Extracellular matrix biomarkers, such as PRO-C3, are useful as biomarkers of advanced liver fibrosis. However, non-invasive biomarkers of early-stage NAFLD, characterized by pericellular fibrosis, are lacking. Here, we measured serological biomarkers of type IV and VIII collagens reflecting the remodeling of the pericellular basement membrane to explore the effect of bariatric surgery on pericellular fibrosis in patients with early NAFLD. METHODS: Seventy patients with severe obesity underwent bariatric surgery. The cohort consisted of 61 % females who had a mean age of 44. Patients had a median NAFLD activity score of 3 and mild-to-moderate fibrosis F0 (3 %), F1 (86 %), and F2 (11 %). Blood samples were taken at baseline, three, six and 12 months after surgery. At 12 months, 40 patients had a follow-up liver biopsy. The biomarkers PRO-C3, PRO-C4, C4M, and PRO-C8 were measured using indirect competitive ELISAs. RESULTS: Twelve months after surgery patients had significantly lower levels of ALT, GGT, HbA1c, fasting glucose, and CRP. The pericellular fibrosis biomarkers, C4M, PRO-C4, and PRO-C8 decreased by 24 %, 18 % and 44 %, respectively (p < 0.0001), while the interstitial matrix fibrosis marker PRO-C3 remained unchanged. Furthermore, baseline C4M was associated with histologically assessed hepatocyte ballooning and lobular inflammation in patients with (p = 0.032) and without (p = 0.032) steatosis, respectively. CONCLUSION: Biomarkers of pericellular fibrosis decrease in early-stage NAFLD after patients undergo bariatric surgery and potentially reflect an improvement in liver histology.

Single-cell transcriptome and cell type-specific molecular pathways of human non-alcoholic steatohepatitis.

The aim of this study is to characterize cell type-specific transcriptional signatures in non-alcoholic steatohepatitis (NASH) to improve our understanding of the disease. We performed single-cell RNA sequencing on liver biopsies from 10 patients with NASH. We applied weighted gene co-expression network analysis and validated our findings using a publicly available RNA sequencing data set derived from 160 patients with non-alcoholic fatty liver disease (NAFLD) and 24 controls with normal liver histology. Our study provides a comprehensive single-cell analysis of NASH pathology in humans, describing 19,627 single-cell transcriptomes from biopsy-proven NASH patients. Our data suggest that the previous notion of "NASH-associated macrophages" can be explained by an up-regulation of normally existing subpopulations of liver macrophages. Similarly, we describe two distinct populations of activated hepatic stellate cells, associated with the level of fibrosis. Finally, we find that the expression of several circulating markers of NAFLD are co-regulated in hepatocytes together with predicted effector genes from NAFLD genome-wide association studies (GWAS), coupled to abnormalities in the complement system. In sum, our single-cell transcriptomic data set provides insights into novel cell type-specific and general biological processes associated with inflammation and fibrosis, emphasizing the importance of studying cell type-specific biological processes in human NASH.

Cardiometabolic effects of antidiabetic drugs in non-alcoholic fatty liver disease.

PURPOSE: Non-alcoholic fatty liver disease (NAFLD) affects about 25% of the population worldwide. NAFLD may be viewed as the hepatological manifestation of metabolic syndrome. Patients with metabolic syndrome due to diabetes or obesity have an increased risk of cardiovascular disease. This narrative review describes cardiometabolic effects of antidiabetic drugs in NAFLD. METHODS: We conducted a systematic search in PubMed and manually scanned bibliographies in trial databases and reference lists in relevant articles. RESULTS: Heart disease is the leading cause of death in NAFLD. Conversely, NAFLD is an independent cardiovascular risk factor in patients suffering from metabolic syndrome. NAFLD is associated with markers of atherosclerosis, and patients have increased risk of ischaemic heart disease. Additionally, patients with NAFLD have increased risk of cardiac dysfunction and heart failure. There are no randomized controlled trials showing clear effects of medical treatment on clinical outcomes in patients with NAFLD. However, based on evidence from small trials and extrapolation from trials evaluating patients with type 2 diabetes, some antidiabetic drugs may be beneficial on cardiovascular function in patients with NAFLD. CONCLUSION: At present, there is promising evidence of a potential effect of antidiabetic drugs for patients with NAFLD. Future studies should address the treatment of NAFLD and the liver-related consequences but also aim at improving the cardiometabolic outcomes.