Expression In Sepsis Research Articles

Organ-Specific Cytokine Gene Expression in Sepsis – an Experimental Study in a Two-Hit Septic Model

Background: Interstinal ischemia and the subsequent cytokine response are believed to play a pivotal role in the pathogenesis of multiple organ failure after trauma, shock, and sepsis. However, the relative importance of the interstinal inflammatory response in comparison with other organs has not been investigated. Material and Methods: Rats were subjected to 45 min of superior mesenteric artery occlusion (first hit) and intraperitoneal endotoxin (15 mg/kg body weight)/sodium chloride challenge 6 h later (second hit). Plasma tumor necrosis factor-alpha (TNF-α), interleukin-(IL-)6 and IL-10 levels were measured by enzyme-linked immunosorbent assay (ELISA). The mRNA expression of TNF-α, IL-1β, IL-6 and IL-10 in lung, liver, mesenteric lymph node and ileum were determined by competitive reverse transcriptase polymerase chain reaction (RT-PCR). Results: Superior mesenteric artery occlusion and endotoxin challenge led to an early increase of plasma TNF-α and IL-10 levels, while the plasma IL-6 response peaked 3 h after intraperitoneal injection of endotoxin. The mRNA expression of all cytokines was significantly increased in the two-hit compared to the one-hit group. Although cytokine mRNA was expressed in the ileum, all cytokines showed significantly higher mRNA levels in the lungs compared to the other organs in the two-hit group. Even in the one-hit group, the TNF-α nRNA expression in the lung was significantly higher compared to the liver. Conclusions: The lung was the primary source of pro- and anti-inflammatory cytokines compared to all other organs in this two-hit sepsis model. However, the gut could be identified as a site of cytokine gene expression. These results furhter confirm the concept, that intestinal mediators reach the systemic circulation via the intestinal lymphatic duct and not the portal vein and therefore lead to an inflammatory response of the lung rather than the liver.

Changes in lymphocyte subpopulations and CD3+/DR + expression in sepsis

To detect lymphocyte subpopulations and CD3+/DR + expression in sepsis. In a prospective clinical study we evaluated subpopulations of lymphocytes and percentage of CD3+/HLA-DR+ lymphocytes using two-color flow cytometry in 40 patients with sepsis and compared them with 34 healthy adults. Septic patients, when compared with healthy controls, have significantly lower percentage and absolute numbers of total T lymphocytes and CD4 T lymphocytes (P < 0.01). Absolute numbers of CD8 T lymphocytes, NK cells, CD3+/DR + lymphocytes and CD4/CD8 ratio were also decreased (P < 0.01). The percentage of B lymphocytes was increased (P < 0.01). Our results are in agreement with previous findings in patients with sepsis after major surgery or trauma. The decreases in the percentage and absolute numbers of circulating lymphocyte subsets in non-surgical sepsis could represent a general reaction to stress. Increased percentage of B lymphocytes is most probably related to the bacterial etiology of the disease.

Alterations in glucose-6-phosphatase gene expression in sepsis.

The influence of sepsis on the expression and activity of hepatic glucose-6-phosphatase (Glu-6-Pase) was examined during the early hyperglycemic phase and the later hypoglycemic phase. Sepsis was induced in anesthetized, fasted rats by cecal ligation and puncture, and liver samples were taken at 0, 0.5, 1, 1.5, and 20 hours after cecal ligation and puncture. The mRNA abundance of hepatic Glu-6-Pase increased fourfold at 0.5 hours over healthy control values, two-fold after 1 hour, and returned to normal after 1.5 hours. This finding was followed by a corresponding increase in Glu-6-Pase activity and was coincident with increased plasma glucose levels and decreased liver glucose-6-phosphate (Glu-6-P) at 0.5 and 1 hours. Plasma insulin and glucagon levels remained unchanged during this period, whereas corticosterone levels increased 2.5-fold over control values. At 20 hours cecal ligation and puncture, plasma glucose levels returned to normal, coincident with a 90% reduction in Glu-6-Pase mRNA abundance. Glu-6-Pase activity and Glu-6-P concentration returned to normal levels, while insulin, glucagon, and corticosterone levels increased significantly, i.e., 40-fold, 6.5-fold, and 6-fold, respectively. The initial rise and subsequent decline in blood glucose correlate very well with a corticosterone-dependent induction of hepatic Glu-6-Pase, mRNA, and protein, followed by an insulin-dependent suppression of its expression.

Gene expression of IL-10 in relationship to TNF-α, IL-1β and IL-2 in the rat brain following middle cerebral artery occlusion

To systematically elucidate the gene expression of inflammatory and immune modulators following middle cerebral artery occlusion (MCAO) in the rat, we studied interleukin-10 (IL-10) along with tumor necrosis factor alpha (TNF-α), interleukin-1 beta (IL-1β) and interleukin-2 (IL-2). Gene expression of these cytokines was studied ipsilateral and contralateral to the MCAO, with mRNA expression levels evaluated 2, 4, 6, 8 and 12 h following permanent MCAO by reverse transcriptase polymerase chain reaction (RT-PCR). In the ischemic hemisphere TNF-α and IL-1β mRNA increased at 2 h following MCAO and peaked at 6 h, with IL-10 mRNA detected only at 6 h. Contralaterally, both TNF-α and IL-1β mRNAs were expressed with a similar pattern to that in the ischemic hemisphere, but at lower levels, with no contralateral IL-10 expression. There was no difference in IL-2 gene expression between control and experimental animals in either hemisphere. These results demonstrate that IL-10 and TNF-α, IL-1β gene expression is induced early following MCAO. The temporal profile of these cytokines is similar to that seen in sepsis, where TNF-α induces IL-10; subsequently IL-10 inhibits TNF-α expression. The similarity of the temporal profile of cytokine expression in sepsis and cerebral ischemia suggests that IL-10 should be studied as a potential inhibitor of TNF-α production in ischemic brain tissue. The factors inducing contralateral expression of the inflammatory cytokines, TNF-α and IL-1β, along with the potential clinical significance of this remote cytokine gene expression, merit further study.