ABSTRACT
Fatty liver (FL) disease is the most common type of chronic liver disease. We hypothesized that liver's response to the process where large droplets of triglyceride fat accumulate in liver cells is reflected also in gene pathway expression in blood. Peripheral blood genome wide gene expression analysis and ultrasonic imaging of liver were performed for 1,650 participants (316 individuals with FL and 1,334 controls) of the Young Finns Study. Gene set enrichment analysis (GSEA) was performed for the expression data. Fourteen gene sets were upregulated (false discovery rate, FDR < 0.05) in subjects with FL. These pathways related to extracellular matrix (ECM) turnover, immune response regulation, prothrombotic state and neural tissues. After adjustment for known risk factors and biomarkers of FL, we found i) integrin A4B1 signaling, ii) leukocyte transendothelial migration, iii) CD40/CD40L and iv) netrin-1 signaling pathways to be upregulated in individuals with FL (nominal p < 0.05). From these all but not ii) remained significantly upregulated when analyzing only subjects without history of heavy alcohol use. In conclusion, FL was associated with blood gene sets of ECM turnover, inflammatory response, immune system activation and prothrombotic state. These may form a systemic link between FL and the development of cardiovascular diseases.
Subject(s)
Fatty Liver/blood , Immune System/metabolism , Signal Transduction/genetics , Adult , Biomarkers/blood , Biomarkers/metabolism , CD40 Antigens/genetics , CD40 Antigens/metabolism , CD40 Ligand/genetics , CD40 Ligand/metabolism , Case-Control Studies , Extracellular Matrix/metabolism , Fatty Liver/genetics , Fatty Liver/pathology , Female , Finland , Gene Expression Regulation , Humans , Integrin alpha4beta1/genetics , Integrin alpha4beta1/metabolism , Leukocytes/cytology , Leukocytes/physiology , Liver/diagnostic imaging , Liver/metabolism , Male , Middle Aged , Netrin-1/genetics , Netrin-1/metabolism , Risk FactorsABSTRACT
BACKGROUND: Prediabetes often occurs together with dyslipidaemia, which is paradoxically treated with statins predisposing to type 2 diabetes mellitus. We examined peripheral blood pathway profiles in prediabetic subjects with (PRD ) and without dyslipidaemia (PR0 ) and compared these to nonprediabetic controls without dyslipidaemia (C0 ). METHODS: The participants were from the Cardiovascular Risk in Young Finns Study, including 1240 subjects aged 34 to 49 years. Genome-wide expression data of peripheral blood and gene set enrichment analysis were used to investigate the differentially expressed genes and enriched pathways between different subtypes of prediabetes. RESULTS: Pathways for cholesterol synthesis, interleukin-12-mediated signalling events, and downstream signalling in naïve CD8+ T-cells were upregulated in the PR0 group in comparison with controls (C0 ). The upregulation of these pathways was independent of waist circumference, blood pressure, smoking status, and insulin. Adjustment for CRP left the CD8+ T-cell signalling and interleukin-12-mediated signalling event pathway upregulated. The cholesterol synthesis pathway was also upregulated when all prediabetic subjects (PR0 and PRD ) were compared with the nonprediabetic control group. No pathways were upregulated or downregulated when the PRD group was compared with the C0 group. Five genes in the PR0 group and 1 in the PRD group were significantly differentially expressed in comparison with the C0 group. CONCLUSIONS: Blood cell gene expression profiles differ significantly between prediabetic subjects with and without dyslipidaemia. Whether this classification may be used in detection of prediabetic individuals at a high risk of cardiovascular complications remains to be examined.
Subject(s)
Cardiovascular Diseases/etiology , Cholesterol/biosynthesis , Dyslipidemias/genetics , Gene Expression , Prediabetic State/genetics , Signal Transduction/genetics , Adult , Blood Glucose , Cardiovascular Diseases/genetics , Dyslipidemias/blood , Dyslipidemias/complications , Female , Finland , Gene Expression Profiling , Humans , Insulin Resistance , Male , Middle Aged , Prediabetic State/blood , Prediabetic State/complications , Up-Regulation , Waist CircumferenceABSTRACT
We used genome wide expression (GWE) data of circulating blood cells and pathway analysis to investigate the inflammatory and other molecular pathways that may be associated with long-standing depressive symptoms. Participants were 607 women and 316 men (mean age 42 years) from the Young Finns Study who participated in three consecutive study phases in 2001, 2007 and 2012. Using Gene-set enrichment analyses (GSEA) we focused our analyses to pathways (available in MSigDB database) that are likely to affect immunological and inflammatory processes. GSEA were performed for blood cell GWE data in 2012. Depressive symptoms were assessed using a modified 21-item Beck Depression Inventory in each of the three study phases. Participants who scored in the top quartile of depressive symptoms in each of the three measurement points (n = 191) differed from other participants (n = 732) in several gene-set pathways related to inflammatory processes or immune-inflammatory signaling including interleukin (IL-1) pathway, and pathways related to various immuno-inflammatory processes, such as toll-like, the NEF protein, the nuclear factor kB, the kinase AKT and the mature B cell antigen receptor pathway (false discovery rates, FDRs<0.12). The results provide novel genome wide molecular evidence that support the association between chronic depressive symptoms and altered immune-inflammatory regulation.
