Project description:Non-alcoholic fatty liver disease (NAFLD) is a common chronic condition caused by the accumulation of fat in the liver. NAFLD may range from simple steatosis to advanced cirrhosis, and affects more than 1 billion people around the world. To date, there has been no effective treatment for NAFLD. In this study, we evaluated the expression of 4 candidate NAFLD biomarkers to assess their possible applicability in the classification and treatment of the disease.Twenty-six obese subjects, who underwent bariatric surgery, were recruited and their liver biopsies obtained. Expression of 4 candidate biomarker genes, PNPLA3, COL1A1, PPP1R3B, and KLF6 were evaluated at gene and protein levels by RT-qPCR and enzyme-linked immunosorbent assay (ELISA), respectively.A significant increase in the levels of COL1A1 protein (P = .03) and PNPLA3 protein (P = .03) were observed in patients with fibrosis-stage NAFLD compared to that in patients with steatosis-stage NAFLD. However, no significant differences were found in abundance of PPP1R3B and KLF6 proteins or at the gene level for any of the candidate.This is the first study, to our knowledge, to report on the expression levels of candidate biomarker genes for NAFLD in the Saudi population. Although PNPLA3 and PPP1R3B had been previously suggested as biomarkers for steatosis and KLF6 as a possible marker for the fibrosis stage of NAFLD, our results did not support these findings. However, other studies that had linked PNPLA3 to fibrosis in advanced NAFLD supported our current finding of high PNPLA3 protein in patients with fibrosis. Additionally, our results support COL1A1 protein as a potential biomarker for the fibrosis stage of NAFLD, and indicate its use in the screening of patients with NAFLD. Further studies are required to validate the use of COL1A1 as a biomarker for advanced NAFLD in a larger cohort.
Project description:Immune infiltration of peripheral natural killer (NK) cells in the brain has been observed in Alzheimer's disease (AD). Immunity-related genes (IRGs) play an essential role in immune infiltration; however, the expression of IRGs and possible regulatory mechanisms involved in AD remain unclear. The peripheral blood mononuclear cells (PBMCs) single-cell RNA (scRNA) sequencing data from patients with AD were analyzed and PBMCs obtained from the ImmPort database were screened for cluster marker genes. IRG activity was calculated using the AUCell package. A bulk sequencing dataset of AD brain tissues was analyzed to explore common IRGs between PBMCs and the brain. Relevant regulatory transcription factors (TFs) were identified from the Human TFDB database. The protein-protein interaction network of key TFs were generated using the STRING database. Eight clusters were identified, including memory CD4 T, NKT, NK, B, DC, CD8 T cells, and platelets. NK cells were significantly decreased in patients with AD, while CD4 T cells were increased. NK and DC cells exhibited the highest IRG activity. GO and KEGG analyses of the scRNA and bulk sequencing data showed that the DEGs focused on the immune response. Seventy common IRGs were found in both peripheral NK cells and the brain. Seventeen TFs were associated with IRG expression, and the PPI network indicated that STAT3, IRF1, and REL were the hub TFs. In conclusion, we propose that peripheral NK cells may infiltrate the brain and contribute to neuroinflammatory changes in AD through bioinformatic analysis of scRNA and bulk sequencing data. Moreover, STAT3 may be involved in the transcriptional regulation of IRGs in NK cells.
Project description:Global gene expression patterns of 2 human steatosis and 9 human non-alcoholic steatohepatitis (NASH) together with their respective control patterns were analyzed to define the non-alcoholic fatty liver disease (NAFLD) progression molecular characteristics and to define NASH early markers from steatosis. Human liver samples of steatosis and non-alcoholic steatohepatitis were selected for RNA extraction and hybridization on Affymetrix microarrays. This dataset is part of the TransQST collection.
Project description:Non-alcoholic fatty liver disease (NAFLD) causes significant global disease burden and is a leading cause of mortality. NAFLD induces a myriad of aberrant changes in hepatocytes at both the cellular and molecular level. Although the disease spectrum of NAFLD is widely recognised, the precise triggers for disease progression are still to be fully elucidated. Furthermore, the propagation to cirrhosis is poorly understood. Whilst some progress in terms of treatment options have been explored, an incomplete understanding of the hepatic cellular and molecular alterations limits their clinical utility. We have therefore reviewed some of the key pathways responsible for the pathogenesis of NAFLD such as innate and adaptative immunity, lipotoxicity and fibrogenesis, and highlighted current trials and treatment options for NAFLD patients.
Project description:Background/aimsImmune and inflammatory cells respond to multiple pathological hits in the development of nonalcoholic steatohepatitis (NASH) and fibrosis. Relatively little is known about how their type and function change through the non-alcoholic fatty liver disease (NAFLD) spectrum. Here we used multi-dimensional mass cytometry and a tailored bioinformatic approach to study circulating immune cells sampled from healthy individuals and people with NAFLD.MethodsCytometry by time of flight using 36 metal-conjugated antibodies was applied to peripheral blood mononuclear cells (PBMCs) from biopsy-proven NASH fibrosis (late disease), steatosis (early disease), and healthy patients. Supervised and unsupervised analyses were used, findings confirmed, and mechanisms assessed using independent healthy and disease PBMC samples.ResultsOf 36 PBMC clusters, 21 changed between controls and disease samples. Significant differences were observed between diseases stages with changes in T cells and myeloid cells throughout disease and B cell changes in late stages. Semi-supervised gating and re-clustering showed that disease stages were associated with fewer monocytes with active signalling and more inactive NK cells; B and T cells bearing activation markers were reduced in late stages, while B cells bearing co-stimulatory molecules were increased. Functionally, disease states were associated with fewer activated mucosal-associated invariant T cells and reduced toll-like receptor-mediated cytokine production in late disease.ConclusionA range of innate and adaptive immune changes begin early in NAFLD, and disease stages are associated with a functionally less active phenotype compared to controls. Further study of the immune response in NAFLD spectrum may give insight into mechanisms of disease with potential clinical application.
Project description:Liver fibrosis is the excessive expression and accumulation of extracellular matrix proteins in the liver. Fibrotic scarring occurs as the consequence of chronic injury and inflammation. While the successful treatment of hepatitis B and C reduced the burden of liver disease related to viral hepatitis, non-alcoholic fatty liver disease (NAFLD) or non-alcoholic steatohepatitis (NASH) are nowadays the leading causes of hepatic fibrosis worldwide. Although basic research activities have significantly advanced our understanding of the molecular disease pathogenesis, the present therapeutic options for fibrosis are still limited. In advanced disease stages, liver transplantation often remains the only curative treatment. This highlights the necessity of preventive strategies to avoid complications of fibrosis, particularly cirrhosis, portal hypertension and liver cancer. Lifestyle modifications (weight loss, exercise, healthy diet) are the basis for prevention and treatment of NAFLD-associated fibrosis. In the present review, we discuss recent advances in antifibrotic prevention and therapy. In particular, we review the current concepts for antifibrotic drug candidates in the treatment of NAFLD and NASH. While some compounds aim at reverting pathogenic liver metabolism, an alternative approach is to disconnect the injury (e.g., NAFLD) from inflammation and/or fibrosis. Investigational drugs typically target metabolic pathways, insulin resistance, hepatocyte death, inflammatory cell recruitment or activation, the gut-liver axis, matrix expression or matrix turnover. While several promising drug candidates failed in phase 2 or 3 clinical trials (including elafibranor, emricasan and selonsertib), promising results with the farnesoid X receptor agonist obeticholic acid, the pan-PPAR agonist lanifibranor and the chemokine receptor CCR2/CCR5 inhibitor cenicriviroc support the expectation of an effective pharmacological therapy for liver fibrosis in the near future. Tackling NAFLD-associated fibrosis from different directions by combinatorial drug treatment and effective lifestyle changes hold the greatest prospects.
Project description:BackgroundArmeniaca sibirica seed kernel oil is rich in oleic acid and linoleic acid, thus holding potential value as a source of high-quality edible oils. However, some regulatory factors involved in fatty acids accumulation in A. sibirica seed kernels remain largely elusive. Thus, the aim of this study was to elucidate the regulatory mechanisms underlying fatty acids biosynthesis in A. sibirica developing seed kernels.MethodsSeed kernels from six plants from a single A. sibirica clone were taken at five different developmental stages (days 30, 41, 52, 63, and 73 after anthesis). Fatty acid composition in seed kernel oil was determined by gas chromatography-mass spectrometry (GC-MS). In addition, transcriptome analysis was conducted using second-generation sequencing (SGS) and single-molecule real-time sequencing (SMRT).ResultsRapid accumulation of fatty acids occurred throughout the different stages of seed kernels development, with oleic acid and linoleic acid as the main fatty acids. A total of 10,024, 9,803, 6,004, 6,719 and 9,688 unigenes were matched in the Nt, Nr, KOG, GO and KEGG databases, respectively. In the category lipid metabolism, 228 differentially expressed genes (DEGs) were annotated into 13 KEGG pathways. Specific unigenes encoding 12 key enzymes related to fatty acids biosynthesis were determined. Co-expression network analysis identified 11 transcription factors (TFs) and 13 long non-coding RNAs (lncRNAs) which putatively participate in the regulation of fatty acid biosynthesis. This study provides insights into the molecular regulatory mechanisms of fatty acids biosynthesis in A. sibirica developing seed kernels, and enabled the identification of novel candidate factors for future improvement of the production and quality of seed kernel oil by breeding.
Project description:BackgroundThe morbidity and mortality rates of patients with non-alcoholic fatty liver disease (NAFLD) have been steadily increasing in recent years. Previous studies have confirmed the important role of ferroptosis in NAFLD development; however, the precise mechanism through which ferroptosis influences NAFLD occurrence remains unclear. The present study aimed to identify and validate ferroptosis-related genes involved in NAFLD pathogenesis and to investigate the underlying molecular mechanisms of NAFLD.MethodsWe downloaded microarray datasets GSE72756 and GSE24807 to identify differentially expressed genes (DEGs) between samples from healthy individuals and patients with NAFLD. From these DEGs, we extracted ferroptosis-related DEGs. GSE89632, another microarray dataset, was used to validate the expression of ferroptosis-related genes. A protein-protein interaction (PPI) network of ferroptosis-related genes was then constructed. The target genes were also subjected to Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses. Finally, competing endogenous RNA networks were constructed. We used the CIBERSORT package to evaluate the infiltration of immune cells infiltration in NAFLD.ResultsFive ferroptosis-related genes (SCP2, MUC1, DPP4, SLC1A4, and TF) were identified as promising diagnostic biomarkers for NAFLD. Enrichment analyses revealed that these genes are mainly involved in metabolic processes. NEAT1-miR-1224-5p-SCP2, NEAT1-miR-485-5p-MUC1, MALAT1-miR-485-5p-MUC1, and CNOT6-miR-145-5p-SLC1A4 are likely to be the potential RNA regulatory pathways that affect NAFLD development. Principal component analysis indicated significant differences in immune cell infiltration between the two groups.ConclusionsThis study identified five ferroptosis-related genes as potential biomarkers for diagnosing NAFLD. The correlations between the expression of ferroptosis-related genes and immune cell infiltration might shed light on the study of the molecular mechanism underlying NAFLD development.
Project description:Global gene expression patterns of 2 human steatosis and 9 human non-alcoholic steatohepatitis (NASH) together with their respective control patterns were analyzed to define the non-alcoholic fatty liver disease (NAFLD) progression molecular characteristics and to define NASH early markers from steatosis.
Project description:Non-alcoholic fatty liver disease is one of the main liver diseases worldwide. The most common cause of death in patients with non-alcoholic fatty liver disease is cardiovascular disease. The relationship between these two conditions has been well established. Indeed, identical reasons may contribute to the development of cardiovascular disease and non-alcoholic fatty liver disease with lifestyle factors such as smoking, sedentariness, poor nutritional habits, and physical inactivity being major aspects. This review focuses on potential pathophysiological mechanisms of cardiovascular disorders in non-alcoholic fatty liver. PubMed, EMBASE, Orphanet, MIDLINE, Google Scholar, and Cochrane Library were searched for articles published between 2006 and 2022. Relevant articles were selected using the following terms: "Non-alcoholic fatty liver disease," "Сardiovascular diseases," "Pathophysiological mechanisms." The reference lists of all identified articles were searched for other relevant publications as well. The pathophysiological mechanisms of cardiovascular disorders in non-alcoholic fatty liver remain largely speculative and may include systemic low-grade inflammation, atherogenic dyslipidemia, abnormal glucose metabolism and hepatic insulin resistance, endothelial dysfunction, gut dysbiosis, as well as the associated cardiac remodeling, which are influenced by interindividual genetic and epigenetic variations. It is clear that the identification of pathophysiological mechanisms underlying cardiovascular disorders in non-alcoholic fatty liver disease will make the selection of therapeutic measures more optimal and effective.