丙酮酸乙酯对实验性结肠炎大鼠结肠组织HMGB1表达及细胞因子的影响

Changes in expression of high mobility group protein B1 in acute liver failure in rats

AIM: To observe the changes in the expression of high mobility group protein B1 (HMGB1) and other inflammatory cytokines in acute liver failure (ALF) in rats.

METHODS: D-galactosamine (D-Gal) and lipopolysaccharide (LPS) were used to establish a model of ALF by intraperitoneal injection. Rats were treated with normal saline alone in a control group. Serum and liver tissues were collected at different time points (3, 6, 12, 48, 72 and 96 h). Serum biochemical indicators were detected, and HMGB1 expression in liver tissue was observed by immunohistochemical analysis. HE staining was performed to evaluate the severity of liver damage. The changes of HMGB1, interleukin 1β (IL-1β), IL-6, and tumor necrosis factor-α (TNF-α) mRNA expression were determined by real-time fluorescent quantitative PCR, and the levels of HMGB1, IL-1β, IL-6 and TNF-α were measured using ELISA kits. rHMGB1 was injected via the tail vein alone or combined with D-Gal and LPS by intraperitoneal injection, and the changes of symptoms and signs and survival rates of rats were observed.

RESULTS: ALF was successfully induced in rats using D-Gal and LPS. In ALF rats, the peak of HMGB1 gene expression and serum levels of HMGB1 were later but lasted longer than IL-1β, IL-6 and TNF-α. Cytoplasmic translocation of HMGB1 was observed as early as 3 h after D-Gal and LPS administration. In 24-48 h, normal liver tissue structures disappeared, and HMGB1 was overflowed from necrotic liver cells and showed diffused yellow staining, full of the entire field of vision. Administration of exogenous rHMGB1 reduced the time to death and increased mortality rates .

CONCLUSION: HMGB1 may be passively leaked by necrosis hepatic cells, which appeared later compared with other inflammatory cytokines. The interaction of HMGB1 and other inflammatory cytokines can promote the inflammation progression in ALF.

Relationship between high mobility group box 1 protein and inflammatory bowel disease

High mobility group box 1 protein (HMGB1) is a DNA binding protein that can promote the maintenance of nucleosomal structures and regulate gene transcription in mammalian cells. HMGB1 is a ubiquitous nuclear protein that is widely distributed among mammalian cells, passively released from necrotic cells and actively released from stimulated inflammatory cells. HMGB1 might function as an endogenous immune adjuvant and play a crucial role in the development of various inflammatory diseases, and blockade of HMGB1 expression attenuates the intestinal inflammation and damage in animal models. This article reviews recent progress in understanding the relationship between HMGB1 and inflammatory bowel disease.

Expression of high mobility group box 1 protein in ulcerative colitis

Ulcerative colitis (UC) is a chronic inflammatory condition of the colon which involves a complex interplay of genetic, immunological and environmental factors. The precise pathogenesis of UC remains unclear till now. The high mobility group box 1 (HMGB1) protein is a nuclear non-histone DNA-binding protein that is present within the nuclei of almost all eukaryotic cells. Recent studies indicate that HMGB1 can be released into the extracellular milieu and mediate inflammatory response, thereby contributing to the pathogenesis of numerous infectious and noninfectious, inflammatory and autoimmune diseases, as well as cancers. Many studies have indicated that HMGB1 is involved in the development of UC. The present paper gives an overview of HMGB1 and UC.