Analysis of the relationship between liver regeneration rate and blood levels

Thermoneutral housing shapes hepatic inflammation and damage in mouse models of non-alcoholic fatty liver disease

Introduction

Inflammation is a common unifying factor in experimental models of non-alcoholic fatty liver disease (NAFLD) progression. Recent evidence suggests that housing temperature-driven alterations in hepatic inflammation correlate with exacerbated hepatic steatosis, development of hepatic fibrosis, and hepatocellular damage in a model of high fat diet-driven NAFLD. However, the congruency of these findings across other, frequently employed, experimental mouse models of NAFLD has not been studied.

Methods

Here, we examine the impact of housing temperature on steatosis, hepatocellular damage, hepatic inflammation, and fibrosis in NASH diet, methionine and choline deficient diet, and western diet + carbon tetrachloride experimental models of NAFLD in C57BL/6 mice.

Results

We show that differences relevant to NAFLD pathology uncovered by thermoneutral housing include: (i) augmented NASH diet-driven hepatic immune cell accrual, exacerbated serum alanine transaminase levels and increased liver tissue damage as determined by NAFLD activity score; (ii) augmented methionine choline deficient diet-driven hepatic immune cell accrual and increased liver tissue damage as indicated by amplified hepatocellular ballooning, lobular inflammation, fibrosis and overall NAFLD activity score; and (iii) dampened western diet + carbon tetrachloride driven hepatic immune cell accrual and serum alanine aminotransferase levels but similar NAFLD activity score.

Discussion

Collectively, our findings demonstrate that thermoneutral housing has broad but divergent effects on hepatic immune cell inflammation and hepatocellular damage across existing experimental NAFLD models in mice. These insights may serve as a foundation for future mechanistic interrogations focused on immune cell function in shaping NAFLD progression.

Acute Heat Stress Induces the Differential Expression of Heat Shock Proteins in Different Sections of the Small Intestine of Chickens Based on Exposure Duration

In this study, we examined the protein and gene expression of heat shock proteins (HSPs) in different sections of the small intestine of chickens. In total, 300 one-day-old Ross 308 broiler chicks were randomly allocated to the control and treatment groups. The treatment group was divided into four subgroups, according to the duration of acute heat exposure (3, 6, 12, and 24 h). The influence of heat stress on the protein and gene expression of HSP70, HSP60, and HSP47 in different sections of the small intestine of chickens was determined. The protein expression of HSP70 and HSP60 was significantly higher at 6 h in the duodenum and jejunum and 12 h in the ileum. The HSP47 protein expression was significantly higher at 3 h in the duodenum and ileum and at 6 h in the jejunum. The gene expression levels of HSP70, HSP60, and HSP47 were significantly higher at the 3 h treatment group than the control group in the duodenum, jejunum, and ileum. The glutamate pyruvate transaminase and glutamate oxaloacetate transaminase levels were significantly higher at 12 and 24 h in the serum of the blood. Acute heat stress affected the expression of intestinal proteins and genes in chickens, until the induction of heat tolerance.

Role of interleukin 6 in liver cell regeneration after hemi-hepatectomy, correlation with liver enzymes and flow cytometric study

Aim of the study

Liver regeneration after hemi-hepatectomy may be affected by several growth factors and cytokines. The aim is to evaluate the importance of interleukin 6 (IL-6) in the induction of liver cell regeneration and find correlations with other parameters such as liver enzymes, and DNA analysis by flow cytometric studies.

Material and methods

80 adult male Sprague-Dawley rats were obtained and divided into two equal groups (n = 40 rats) to undergo 70% partial hepatectomy: group 1 - untreated (control) group; 40 rats not treated; and group 2 - treated group, 40 rats treated with IL-6 35 μg/100 gm body weight according to a lethality study for a period of 4 days, then hepatic resection was carried out according to the steps of Higgins and Anderson. Assessment of liver enzymes and bilirubin level was done. Flow cytometric study was done using a flow cytometer (FACSCalibur; Becton Dickinson) and DNA content was estimated with CellQuest software (Becton Dickinson).

Results

The levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP) were significantly higher in the untreated group of rats with liver resection. A higher value of bilirubin was observed in the treated group. Rat weight at sacrification was significantly lower in the group of rats treated with IL-6 than those without treatment, p < 0.001. Liver weight at sacrification was significantly higher in the group of rats treated with IL-6 (p < 0.001). The percentage of apoptotic cells with hypodiploid DNA content was determined from DNA histograms. Untreated rat resected liver showed a peak pattern that represented liver damage with high damage of 73.4%.

Conclusions

Interleukin 6 is of value in induction of liver cell regeneration after seventy percent hemi-hepatectomy as evident by increased liver cell mass, liver enzymes and flow cytometric analysis.