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Miekus, K.

Publications and source records attributed to Miekus, K..

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Hepatic MCPIP1 protein levels are reduced in NAFLD patients and are predominantly expressed in cholangiocytes and liver endothelium

Nonalcoholic fatty liver disease (NAFLD) is characterized by the excessive accumulation of fat in hepatocytes. NAFLD can range from simple steatosis to the aggressive form called nonalcoholic steatohepatitis (NASH), which is characterized by both fatty liver and liver inflammation. Without proper treatment, NAFLD may further progress to lifethreatening complications, such as fibrosis, cirrhosis or liver failure. Monocyte chemoattractant protein-induced protein 1 (MCPIP1, alias Regnase 1) is a negative regulator of inflammation, acting through the cleavage of transcripts coding for proinflammatory cytokines and the inhibition of NF{kappa}B activity. In this study, we investigated MCPIP1 expression in the liver and peripheral blood mononuclear cells (PBMCs) collected from a cohort of 36 control and NAFLD patients hospitalized due to bariatric surgery or primary inguinal hernia laparoscopic repair. Based on liver histology data (H&E and Oil Red O staining), 12 patients were classified into the nonalcoholic fatty liver (NAFL) group, 19 into the NASH group and 5 into the control (non-NAFLD) group. Biochemical characterization of patient plasma was followed by expression analysis of genes regulating inflammation and lipid metabolism. The MCPIP1 protein level was reduced in the livers of NAFL and NASH patients in comparison to non-NAFLD control individuals. Additionally, in all groups of patients, immunohistochemical staining showed that the expression of MCPIP1 was higher in the portal fields and bile ducts in comparison to the liver parenchyma and central vein. The liver MCPIP1 protein level negatively correlated with hepatic steatosis but not with patient BMI or any other analyte. The MCPIP1 level in PBMCs did not differ between NAFLD patients and control patients. Similarly, in patients PBMCs there were no differences in the expression of genes regulating {beta}-oxidation (ACOX1, CPT1A, and ACC1) and inflammation (TNF, IL1B, IL6, IL8, IL10, and CCL2), or transcription factors controlling metabolism (FAS, LCN2, CEBPB, SREBP1, PPARA, and PPARG). We have demonstrated that MCPIP1 protein levels are reduced in NAFLD patients, but further research is needed to investigate the specific role of MCPIP1 in NAFL initiation and the transition to NASH.

molecular biology↗

Deletion of Mcpip1 in Mcpip1AlbKO mice recapitulates the phenotype of human primary biliary cholangitis

Background & AimsPrimary biliary cholangitis (PBC) is an autoimmune disease characterized by progressive destruction of the intrahepatic bile ducts. The immunopathology of PBC involves excessive inflammation; therefore, negative regulators of inflammatory response, such as Monocyte Chemoattractant Protein-1-Induced Protein-1 (MCPIP1, alias Regnase1) may play important roles in the development of PBC. The aim of this work was to verify whether Mcpip1 expression protects against development of PBC. MethodsGenetic deletion of Zc3h12a was used to characterize the role of Mcpip1 in the pathogenesis of PBC. 6-52-week-old Mcpip1fl/fl and Mcpip1AlbKO mice were used for immunohistochemical, biochemical and molecular tests. ResultsWe found that Mcpip1 deficiency in the liver recapitulates most of the features of human PBC, in contrast to mice with Mcpip1 deficiency in myeloid cells (Mcpip1LysMKO mice), which present with robust myeloid cell-driven systemic inflammation. In Mcpip1AlbKO livers, intrahepatic bile ducts displayed proliferative changes with inflammatory infiltration, bile duct destruction, and fibrosis leading to cholestasis. In plasma, increased concentrations of IgG, IgM, and AMA autoantibodies (anti-PDC-E2) were detected. Interestingly, the phenotype of Mcpip1AlbKO mice was robust in 6-week-old and 52-week-old mice, but milder in 12-24-week-old mice, suggesting early prenatal origin of the phenotype and age-dependent progression of the disease. Hepatic transcriptome analysis of 6-week-old and 24-week-old Mcpip1AlbKO mice showed 812 and 8 differentially expressed genes (DEGs), respectively, compared with age-matched control mice, and revealed a distinct set of genes compared to those previously associated with development of PBC. ConclusionsThe phenotype of Mcpip1AlbKO mice recapitulates most of the features of human PBC, and demonstrates early prenatal origin and age-dependent progression of PBC. Therefore, Mcpip1AlbKO mice provide a unique model for the study of PBC. Lay summaryDeletion of hepatic Mcpip1 in Mcpip1AlbKO mice leads to development of PBC that recapitulates phenotype of human patients. These animals, show early prenatal origin and age-dependent progression of the disease. Thus, Mcpip1AlbKO mice provide a unique model for studying PBC.

pathology↗