1. Endocannabinoid receptor CB2 in nonalcoholic fatty liver disease.
- Author
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Mendez-Sanchez N, Zamora-Valdes D, Pichardo-Bahena R, Barredo-Prieto B, Ponciano-Rodriguez G, Bermejo-Martínez L, Chavez-Tapia NC, Baptista-González HA, and Uribe M
- Subjects
- Fatty Liver pathology, Hepatitis metabolism, Hepatitis pathology, Humans, Immunohistochemistry, Liver metabolism, Liver pathology, Prospective Studies, RNA, Messenger metabolism, Receptor, Cannabinoid, CB2 genetics, Reverse Transcriptase Polymerase Chain Reaction, Tissue Distribution, Fatty Liver metabolism, Receptor, Cannabinoid, CB2 metabolism
- Abstract
Background and Aim: Fatty infiltration and fibrosis are major issues in chronic liver disease. Recent reports suggest a role for the endocannabinoid system in these processes., Aim: To characterize localization and expression of CB2 in normal liver and nonalcoholic fatty liver., Methods: We studied 64 liver biopsies: eight were considered normal; 56 had a diagnosis of nonalcoholic fatty liver disease (NAFLD); 32 with nonalcoholic steatosis and 24 nonalcoholic steatohepatitis (NASH). CB2 immunolocalization was studied in 38 samples in paraffin blocks using immunohistochemistry, and a computerized semiquantitative analysis was carried out. CB2 mRNA expression was assessed through RT-PCR in 26 frozen liver samples and the ratio CB2/beta-actin was used to evaluate differences between groups. Statistical analysis was performed with central tendency measures and the Mann-Whitney U-test. We considered as significant differences those with a P-value <0.05., Results: Neither parenchymal nor nonparenchymal cells in normal liver tissue react towards anti-CB2 antibodies. All the samples from patients with steatosis and nonalcoholic steatohepatitis showed hepatocellular immunoreactivity. Cholangiocytes were positive only in the NAFLD group. Normal liver tissue showed a normalized CB2/beta-actin ratio of 0.001+/-0.01, steatosis 6.52+/-17.3 (P=0.05 vs normal) and NASH 6.49+/-12.2 (P=0.06 vs normal and P=0.6 vs steatosis)., Conclusion: CB2 receptors are expressed by hepatocytes in nonalcoholic fatty liver disease but not in normal liver.
- Published
- 2007
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