Resveratrol Restores Neuronal Tight Junction Proteins Through Correction of Ammonia and Inflammation in CCl4-Induced Cirrhotic Mice

• Published in: Molecular neurobiology 2019-07, Vol.56 (7), p.4718-4729
• Main Authors: Vairappan, Balasubramaniyan, Sundhar, M., Srinivas, B. H.
• Format: Article
• Language: English
• Subjects: Ammonia; Antioxidants; Bilirubin; Biomedical and Life Sciences; Biomedicine; Blood-brain barrier; Brain; Carbon tetrachloride; CCL4 protein; Cell Biology; Cirrhosis; Hepatic encephalopathy; Hyperammonemia; IL-1β; Inflammation; Liver; Liver cirrhosis; Liver diseases; Mice; Neurobiology; Neurological complications; Neurology; Neurosciences; NF-κB protein; Nitric-oxide synthase; Oxidative stress; Protein expression; Proteins; Resveratrol; Tumor necrosis factor-α; Water content; Western blotting; Zonula occludens-1 protein
• ISSN: 0893-7648; 1559-1182
• DOI: 10.1007/s12035-018-1389-x

Systemic inflammation and ammonia (hyperammonemia) act synergistically in the pathogenesis of hepatic encephalopathy (HE), the neurobehavioral sequelae of advanced liver disease. In cirrhotic patients, we have recently observed elevated levels of circulating neuronal tight junction (TJ) protein, zonula occludens 1 (ZO-1), reflective of a change to blood–brain barrier (BBB) integrity. Moreover, ZO-1 levels positively correlated with hyperammonemia, although any potential relationship remains unclear. Using a carbon tetrachloride (CCl 4 )–induced mouse model of cirrhosis, we primarily looked to explore the relationship between neuronal TJ protein expression and hyperammonemia. Secondarily, we assessed the potential role of a natural antioxidant, resveratrol, on neuronal TJ protein expression and hyperammonemia. Over 12 weeks, male Swiss mice were randomized ( n  = 8/group) to either naïve controls or induced cirrhosis, using two doses of intraperitoneal CCl 4 (0.5 ml/kg/week). After 12 weeks, naïve and cirrhotic mice were randomized to receive either 2 weeks of par-oral resveratrol (10 mg/kg). Plasma samples were analyzed for ammonia, liver biochemistry (ALT, AST, albumin, and bilirubin), and pro-inflammatory cytokines (TNF-α and IL-1β), and brain tissue for brain water content, TJ protein expression (e.g., ZO-1, claudin 5, and occludin), and tissue oxidative stress and inflammatory markers (NF-κB and iNOS) using western blotting. Compared to naïve mice, cirrhosis significantly increased circulating ammonia, brain water, ALT, AST, TNF-α, IL-1β, 4HNE, NF-κB, and iNOS levels, with a concomitant reduction in all TJ proteins ( P