HCV levels correlate with the expression of Netrin-1 in the liver biopsies of HCV-infected patients.

A. HCV-positive samples exhibit the highest levels of Netrin-1 mRNA of all the chronic liver disease biopsies. The levels of Netrin-1 mRNA were quantified by RT-qPCR. Statistical significance was determined using the Mann-Whitney test. B. Positive correlation between intrahepatic levels of HCV and Netrin-1 mRNA. HCV RNA and Netrin-1 mRNA were quantified by RT-qPCR. Statistical significance was determined using the Spearman test. An outlier test was run to confirm these results. C and D. Netrin-1 mRNA parallels HCV RNA levels upon treatment. HCV RNA and Netrin-1 mRNA were quantified by RT-qPCR in paired biopsies, before and after treatment, of partially responding patients (C,D left panels) and nonresponding patients (C,D, right panels). E. Parenchymal Netrin-1 staining is associated with HCV infection status in HCV-infected patients. Uninfected, chronic liver disease samples (non-cirrhotic sample, n = 1; alcohol-related cirrhosis samples, n = 3) and HCV genotype 1-infected cirrhosis samples (n = 4) were analyzed. Representative images of Netrin-1 staining (upper panels) and HCV E2 staining (lower panels) are shown. F. Netrin-1 protein expression is increased in HCV-positive samples. The level of Netrin-1 was quantified by immunoblotting using recombinant Netrin-1 (rec. Net) as a control. G. The levels of Netrin-1 mRNA are higher in HCV+ versus HCV- biopsies, regardless of the histological stage, from normal liver to HCC. Intrahepatic Netrin-1 mRNA levels were quantified by RT-qPCR. Statistical significance was determined using the Mann-Whitney test, p < 0.05. Fibrosis scores were determined by histopathology and using the Fibroscan method [22]. The underlying data for panels in this figure can be found in S1 Data.