Astaxanthin prevents ischemia-reperfusion injury of the steatotic liver in mice

<div><p>Steatosis has a low tolerance against ischemia-reperfusion injury (IRI). To prevent IRI in the steatotic liver, we attempted to elucidate the protective effect of astaxanthin (ASTX) in the steatotic liver model by giving mice a methionine and choline-deficient high fat (MCDHF) diet. Levels of lipid peroxidation and apoptosis, the expression of inflammatory cytokines and heme oxygenase (HO)-1, in the liver were assessed. Reactive oxygen species (ROS), inflammatory cytokines, apoptosis-related proteins and members of the signaling pathway were also examined in isolated Kupffer cells and/or hepatocytes from the steatotic liver. ASTX decreased serum ALT and AST levels, the amount of TUNEL, F4/80, or 4HNE-positive cells and the mRNA levels of inflammatory cytokines in MCDHF mice by IRI. Moreover, HO-1 and HIF-1α, phosphorylation of Akt and mTOR expressions were increased by ASTX. The inflammatory cytokines produced by Kupffer, which were subjected to hypoxia and reoxygenation (HR), were inhibited by ASTX. Expressions of Bcl-2, HO-1 and Nrf2 in hepatocytes by HR were increased, whereas Caspases activation, Bax and phosphorylation of ERK, MAPK, and JNK were suppressed by ASTX. Pretreatment with ASTX has a protective effect and is a safe therapeutic treatment for IRI, including for liver transplantation of the steatotic liver.</p></div

Liver Cancer in Atomic-bomb Survivors: Histological Characteristics and Relationships to Radiation and Hepatitis B and C Viruses

Histological features of primary liver cancer among atomic-bomb survivors and their relationship to hepatitis B (HBV) and C viral (HCV) infections are of special interest because of the increased risk of liver cancer in persons exposed to ionizing radiation and the high and increasing liver cancer rates in Japan and elsewhere. We conducted a pathology review of liver cancers occurring from 1958 to 1987 among subjects in the 120,321 member cohort of 1945 Hiroshima and Nagasaki residents. A panel of pathologists classified tumor histological types and defined accompanying cirrhotic changes of the liver. Archival tissue samples were assessed for HBV using pathology stains and PCR. Reverse transcriptase (RT) PCR was used to determine HCV status. We used unconditional logistic regression to compare 302 hepatocellular carcinoma (HCC) cases to 53 cholangiocarcinoma (CC) cases, adjusting for age, year of diagnosis, sex and viral status. Cirrhotic changes occurred significantly more often among HCC than CC cases (76% in HCC and 6% in CC). Compared to CC cases, HCC cases were 10.9 times more likely to be HBV-positive (95% confidence interval: 2.1-83.2) and 4.3 times more likely to be HCV-positive (95% confidence interval: 1.1-20.5). No significant differences were found between HCC and CC cases in radiation exposures. The predominance of HCC in the atomic-bomb survivors follows the background liver cancer pattern in Japan. Our findings suggest that HBV and HCV are involved in the pathogenesis of HCC with or without cirrhosis and are significantly less important in that of CC

ASTX prevented steatotic primary hepatocyte apoptosis when hepatocytes subjected to HR.

<p>(A) Expressions of Bax, Bcl-2, cleaved caspase-9, caspase-9, cleaved caspase-3, caspase-3 of steatotic primary hepatocyte by hypoxia/reoxygenation injury were detected by western blot analysis. Representative blot (left) and quantified protein levels (right) are shown(n = 3). (B) Protein expression of p38 MAPK, p-p38 MAPK, ERK, p-ERK, JNK and p-JNK was detected by western blots(n = 3). α-tubulin was used as a loading control. Representative blot (up) and quantified protein levels (down) are shown. Data are expressed as the means ± SEM; *p< 0.05, **p< 0.01. Data are representative of three independent experiments and indicate the mean ratio of triplicate results from each experiment.</p

ASTX decreased the inflammatory cytokines expression and the biochemical parameters, but increased the HO-1 and HIF-1α expression in the steatotic liver under IR injury.

<p>(A) The serum ALT and AST levels of 15 minutes ischemia and 3 hours reperfusion. (B) The mRNA expression of IL-6, osteopontin (OPN), inducible nitric oxide synthase (iNOS), HO-1 and in HIF-1α in different groups. (Data are representative of 4~7 animals for each group). Data are expressed as the means ± SEM; *p < 0.05.</p

ASTX attenuated necrosis, infiltration of macrophages, oxidant stress and apoptosis as well as the biochemical parameters related to IR injury in the steatotic liver.

<p>(A) The necrotic cells, TUNEL-positive cells, F4/80-positive cells and 4-HNE-positive cells in MCDHF diet, IR and ASTX treatment group were indicated arrows. Scale bars represent 200μm, respectively. (B) The number of necrotic areas, TUNEL-positive cells, F4/80-positive cells and 4-HNE positive cells were counted. Data are expressed as the means ± SEM; *p < 0.05.</p