Hepatic expression of miR-122, miR-126, miR-136 and miR-181a and their correlation to histopathological and clinical characteristics of patients with hepatitis C

It has been shown for hepatitis C virus (HCV) infection that host miRNAs contribute to the replication of the viral RNA genome. However, the clinical impact of these and many other cellular miRNAs on HCV in humans is still largely unclear. We therefore analysed the expression of miR-122, miR-126, miR-181a and miR-136 in HCV-infected patients. The study included liver biopsies of 65 patients infected with HCV of different genotypes (gt 1, gt 1a, gt 1b, gt 3 and gt 4) and nine noninfected individuals. Expression analysis of miRNAs was performed by qPCR, and they were analysed for differences between patient gender and age, genotypes, stage of fibrosis, grade of inflammation, serum level of liver enzymes, serum viral load, the presence of steatosis and mode of transmission. Different target prediction algorithms were used to search for targets of analyzed miRNAs. Statistical analysis revealed significant up-regulation of miR-136 and down-regulation of miR-126 and miR-181a in patients infected with HCV of different genotypes compared with noninfected individuals. The same expression pattern was observed in different stages and grades of liver disease. miR-122 was up-regulated in women relative to men and associated to portal inflammation, miR-122 and miR-126 correlated with serum HCV load and miR-136 and miR-122 correlated with the presence of steatosis. miR-126 and miR-136 were differentially expressed between different modes of HCV transmission. There were approximately 2000 different targets predicted for all four miRNAs and each of the analyzed miRNAs could be involved in more than a 100 different biochemical pathways. miR-122, miR-126, miR-136 and miR-181a have been shown to be involved in HCV infection with different genotypes. Their expression has been associated with the gender, stage and grade of liver disease, mode of transmission, serum HCV load and the presence of steatosis. Numerous target genes and biochemical pathways are predicted for each of the analyzed miRNAs. All these results suggest their role in HCV-infected liver disease.

Familial tauopathy with P364S MAPT mutation: clinical course, neuropathology and ultrastructure of neuronal tau inclusions

AIMS

This report presents the clinical course, neuropathology and ultrastructure of neuronal tau inclusions of four Slovene relatives with P364S MAPT mutation.

METHODS

The clinical history of three out of four P364S MAPT mutation carriers was taken. After formalin fixation, thorough sampling of the central nervous system was followed by paraffin embedding, H&E, Gallyas, Bielschowsky and immunostaining with AT8, anti-3R, anti-4R tau, anti-amyloid-β, anti-TDP43 and anti-alpha-synuclein antibodies. The distribution and density of different types of neuronal tau inclusions were semiquantitatively assessed. In addition, the ultrastructure of neuronal tau inclusions was analysed.

RESULTS

Macroscopic examination of the brains was unremarkable. Microscopically, neuronal tau inclusions of almost all known types were widespread and distributed fairly uniformly in all cases. Pick bodies and swollen neurones were found in only one family member. Mutant tau was composed of 3R and 4R isoforms, with a slight predominance of 3R tau. Composite neuronal tau inclusion (CNTI), found in all four relatives, was a hallmark of the P364S MAPT mutation. CNTI showed compartmental differences in H&E and Gallyas staining, tau isoforms immunolabelling and ultrastructure, displaying fuzzy fibrils in the core and paired twisted tubules at the periphery.

CONCLUSIONS

P364S MAPT mutation is characterized clinically by a variable combination of frontotemporal dementia, parkinsonism and motor neurone disease of short duration, and neuropathologically by a widespread uniform distribution of all known neuronal tau inclusions in one family member. Two-compartment CNTI is a unique characteristic of the P364S MAPT mutation.