Comparison of the effects of different calorie amounts of enteral nutrition in hypercatabolism associated with ghrelin-POMC in endotoxemic rats.

BACKGROUND: Hypercatabolism often occurs in critically ill patients, and it increases infection rates and mortality in these patients. Enteral nutrition (EN) is commonly used in case of hypercatabolism. However, the effect of amount of calories in EN on hypercatabolism remains unexplored. OBJECTIVE: Here, we compared the effect of low-calorie, medium-calorie and high-calorie EN on hypercatabolism in the acute phase of endotoxemia, which is associated with gastrointestinal hormones and hypothalamic neuropeptide proopiomelanocortin (POMC). METHODS: Overall 84 adult male Sprague-Dawley rats were used for research. A set of rats were divided into 5 groups, Control (NS) and lipopolysaccharide (LPS) groups were fed a standard chow diet; LPS + L (LPS + 40 kcal/kg/day EN), LPS + M (LPS + 80 kcal/kg/day EN) and LPS + H (LPS + 120 kcal/kg/day EN) groups received EN through a gastric tube for 3 days. Another set of rats were used for parallel control experiment and divided into 5 groups: NS + F (saline + fasting) and LPS + F (LPS + fasting) groups were given no food, NS + L (saline + 40 kcal/kg/day EN), NS + M (saline + 80 kcal/kg/day EN) and NS + H (saline + 120 kcal/kg/day EN) groups received EN through a gastric tube for 3 days. Hypercatabolism was evaluated by assessing skeletal muscle protein synthesis and atrophy, insulin resistance, and corticosterone levels. Moreover, serum inflammatory factors, gastrointestinal hormones, hypothalamic ghrelin, growth hormone secretagogue receptor-1α, hypothalamic neuropeptide, and intestinal injury indicators were detected. RESULTS: Low-calorie EN effectively increased serum and hypothalamic ghrelin possibly due to slight intestinal barrier damage, thereby decreasing hypothalamic POMC expression; consequently, it alleviated rat insulin resistance, reduced blood cortisol levels and muscle atrophy, and improved the survival rate of rats in the acute phase of endotoxemia. Interestingly, with an increase in calories in enteral nutrition, the aforementioned effects did not increase. CONCLUSIONS: Low-calorie EN could effectively increase gastrointestinal hormone ghrelin by reducing intestinal damage and suppressing POMC expression to ameliorate hypercatabolism when compared with medium-calorie and high-calorie EN. Therefore Low-calorie EN may be preferred for providing EN in the acute stage of endotoxemia.

Association of coagulation disturbances with severity of COVID-19: a longitudinal study.

OBJECTIVES: Coagulation dysfunction is an evident factor in the clinical diagnosis and treatment of patients with coronavirus disease 2019 (COVID-19), appearing even in COVID-19 patients with normal inflammation indices. Therefore, this study aimed to analyze the characteristics of coagulation function indices in COVID-19 patients to investigate possible mechanisms through the comparison of non-severe and severe COVID-19 patients. METHODS: We included 143 patients whose clinical characteristics, coagulation function, and other indices such as inflammatory factors were collected and compared based on disease severity. RESULTS: Activated partial thromboplastin time (APTT), D-dimer, and fibrinogen levels were evidently higher in the severe group than in the non-severe group. Among non-severe COVID-19 patients, the aforementioned indicators depicted increasing trends, but the fibrinogen level alone was higher than normal. However, in severe COVID-19 patients, values of all three indices were higher than normal. In severe COVID-19 patients, fibrinogen and D-dimer were correlated with several inflammation indices during the early stage of the disease. However, no correlation between fibrinogen and inflammatory factors was observed in non-severe COVID-19 patients at any time point. DISCUSSION: Results revealed that the hypercoagulability tendency of severe COVID-19 patients was more evident. The relationship between coagulation function and inflammatory factors showed that changes in coagulation function in severe COVID-19 patients may be related to abnormal increase in inflammatory factors at an early stage; however, in non-severe COVID-19 patients, there might be other factors leading to abnormal coagulation. CONCLUSION: Inflammatory factors were not the only cause of abnormal coagulation function in COVID-19 patients.

Timing of insulin therapy affects the inflammatory response in endotoxemic rats.

The aim of the present study was to determine whether timing of insulin administration influences the hepatic and serum proinflammatory and anti-inflammatory cytokines during endotoxemia stimulated by lipopolysaccharide (LPS). Eighty-one male Sprague-Dawley rats were divided into different time groups and insulin was given 30 min pre-LPS administration or hour 0, 1, 3, 6, 12, 24 after the induction of endotoxemia, respectively. Hepatic and serum proinflammatory cytokines IL-1ß, IL-6, and TNF-α, and anti-inflammatory cytokine IL-10 were detected 24 and 48 h after the induction of endotoxemia. Compared with sham control rats, serum concentrations of proinflammatory cytokines IL-1ß, IL-6, and TNF-α and anti-inflammatory cytokine IL-10 significantly increased on 24 and 48 h after induction of endotoxemia. Similarly, LPS administration also significantly increased the hepatic IL-1ß, TNF-α, IL-6, and IL-10 protein concentration 48 h after LPS injection. Compared with levels in positive LPS controls animals receiving saline, on 24 and 48 h after LPS injection, insulin administrated ahead of 6 h after LPS injection significantly decreased the serum IL-1ß, IL-6, and TNF-a concentration (P < 0.05), and significantly increased anti-inflammatory cytokine IL-10 concentration (P < 0.05); hepatic IL-1ß and IL-6 expression were (P < 0.05) significantly decreased compared with levels in positive LPS controls. But, the significant decrease of hepatic TNF-a expression and significant increase of hepatic IL-10 were only seen in the animals in which insulin was administrated at 30 min pre-LPS or coadministrated with LPS. Insulin administrated 6 h after LPS injection lost the ability to significantly reduce serum or hepatic IL-1ß, TNF-α, and IL-6 concentrations. Insulin has a protective role in systemic inflammatory response syndrome related to sepsis, such as downregulation of proinflammatory cytokines and upregulation of anti-inflammatory cytokine production. However, timing of insulin administrated may change its effect of inflammatory response in endotoxemic rats. Insulin administrated 6 h after LPS injection weaken the ability to protect inflammatory response related to sepsis.

Insulin alleviates degradation of skeletal muscle protein by inhibiting the ubiquitin-proteasome system in septic rats.

Hypercatabolism is common under septic conditions. Skeletal muscle is the main target organ for hypercatabolism, and this phenomenon is a vital factor in the deterioration of recovery in septic patients. In skeletal muscle, activation of the ubiquitin-proteasome system plays an important role in hypercatabolism under septic status. Insulin is a vital anticatabolic hormone and previous evidence suggests that insulin administration inhibits various steps in the ubiquitin-proteasome system. However, whether insulin can alleviate the degradation of skeletal muscle protein by inhibiting the ubiquitin-proteasome system under septic condition is unclear. This paper confirmed that mRNA and protein levels of the ubiquitin-proteasome system were upregulated and molecular markers of skeletal muscle proteolysis (tyrosine and 3-methylhistidine) simultaneously increased in the skeletal muscle of septic rats. Septic rats were infused with insulin at a constant rate of 2.4 mU.kg-1.min-1 for 8 hours. Concentrations of mRNA and proteins of the ubiquitin-proteasome system and molecular markers of skeletal muscle proteolysis were mildly affected. When the insulin infusion dose increased to 4.8 mU.kg-1.min-1, mRNA for ubiquitin, E2-14 KDa, and the C2 subunit were all sharply downregulated. At the same time, the levels of ubiquitinated proteins, E2-14KDa, and the C2 subunit protein were significantly reduced. Tyrosine and 3-methylhistidine decreased significantly. We concluded that the ubiquitin-proteasome system is important skeletal muscle hypercatabolism in septic rats. Infusion of insulin can reverse the detrimental metabolism of skeletal muscle by inhibiting the ubiquitin-proteasome system, and the effect is proportional to the insulin infusion dose.