Pneumosepsis survival in the setting of obesity leads to persistent steatohepatitis and metabolic dysfunction

BACKGROUND

As critical care practice evolves, the sepsis survivor population continues to expand, often with lingering inflammation in many organs, including the liver. Given the concurrently increasing population of patients with NAFLD, in this study, we aimed to understand the long-term effect of sepsis on pre-existing NAFLD and hyperglycemia.

METHODS

Male mice were randomized to a high-fat diet or a control diet (CD). After 24 weeks on diet, mice were inoculated with Klebsiella pneumoniae (Kpa). Serial glucose tolerance tests, and insulin and pyruvate challenge tests were performed 1 week before infection and at 2 and 6 weeks after infection. Whole tissue RNA sequencing and histological evaluation of the liver were performed. To test whether persistent inflammation could be reproduced in other abnormal liver environments, mice were also challenged with Kpa after exposure to a methionine-choline-deficient high-fat diet. Finally, a retrospective cohort of 65,139 patients was analyzed to evaluate whether obesity was associated with liver injury after sepsis.

RESULTS

After Kpa inoculation, high-fat diet mice had normalized fasting blood glucose without a change in insulin sensitivity but with a notable decrease in pyruvate utilization. Liver examination revealed focal macrophage collections and a unique inflammatory gene signature on RNA analysis. In the clinical cohort, preobesity, and class 1 and class 2 obesity were associated with increased odds of elevated aminotransferase levels 1-2 years after sepsis.

CONCLUSIONS

The combination of diet-induced obesity and pneumosepsis survival in a murine model resulted in unique changes in gluconeogenesis and liver inflammation, consistent with the progression of benign steatosis to steatohepatitis. In a cohort study, obese patients had an increased risk of elevated aminotransferase levels 1-2 years following sepsis.

Studies on hypoglycaemic effects of polyherbal preparation in streptozotocin-induced diabetic male albino rats

Many traditional treatments have been recommended in the alternative system of medicine for diabetes mellitus. However, the mode of action of most of the herbals used has not been defined. It has been reported that sex hormones are important regulators of insulin-mediated events in skeletal muscles. In view of this, a novel herbal preparation containing antidiabetic and aphrodisiac plants was used in the present study. Adult male albino rats were divided into following groups after induction of diabetes. Rats were given an intraperitoneal (i.p.) injection of streptozotocin (STZ), at a dose of 65 mg/kg body weight after overnight fasting, to induce diabetic state with blood glucose levels >250 mg/dL. Group 1-Control rats treated with single i.p. injection of vehicle, Group 2-Rats treated with polyherbal preparation (PHP; 500 mg/kg body weight by oral intubation, morning and evening for 30 days), Group 3-STZ-diabetic rats treated orally with equal volumes of vehicle (water) alone and Group 4-STZ-diabetic rats treated with PHP after 10 days of diabetic induction. STZ-diabetes decreased the body weight, serum insulin level and glucose oxidation in liver and skeletal muscles but increased the fasting blood glucose level. After polyherbal treatment, body weight and glucose oxidation were completely restored to control level while serum insulin level was restored partially and the glucose tolerance was significantly improved. There was a significant decrease in total haemoglobin (Hb) level of diabetic rats when compared to control but polyherbal treatment significantly improved the same. However, the other parameters studied (red blood cell [RBC], white blood corpuscle [WBC], packed cell volume [PCV], mean corpuscular volume [MCV] and mean corpuscular haemoglobin [MCH]) were unaltered. In conclusion, the anti-diabetic properties of PHP appear to be mediated through pancreatic beta-cell regeneration, resulting in maintenance of optimal blood glucose and its oxidation in liver and skeletal muscles.

Effects of excess corticosterone on NADPH generating enzymes and glucose oxidation in Leydig cells of adult rats

Clinical and experimental studies have shown the adverse effects of excess glucocorticoid on testicular testosterone production. The NADPH co-enzyme has been recognized as an important factor that regulates several steps in steroidogenesis, while glucose oxidation acts as a limiting factor on testicular testosterone production. Nevertheless, the impact of excess corticosterone, the stress hormone on testicular NADPH availability and glucose oxidation is unknown. Therefore, the present study was designed to assess the specific effects of excess corticosterone on Leydig cell NADPH generating enzymes and glucose oxidation. Adult Wistar rats (200-250 g, b.w.) were treated with corticosterone-21-acetate (2 mg/ 100 g, b.w., i.m., twice daily) for 10 days and corticosterone-21-acetate plus luteinizing hormone (LH) (100 microg/kg b.w., i.m., daily) for 10 days. After the treatment period, experimental animals and controls were killed, blood was collected and the sera separated for testosterone assay. Testes were removed and Leydig cells were isolated, purified and used for estimating the specific activity of NADPH generating enzymes and 14C-glucose oxidation. Serum testosterone, Leydig cellular 14C-glucose oxidation and the specific activities of 6-phosphogluconate dehydrogenase (6-PGDH), NADP-isocitrate dehydrogenase (ICDH) and malic enzyme were significantly decreased in corticosterone-treated rats. Co-administration of LH with corticosterone maintained the specific activities of 6-PGDH and ICDH and 14C-glucose oxidation at control level. Nevertheless, serum testosterone and Leydig cellular malic enzyme activity showed a significant decrease in these rats. In conclusion, the inhibitory effects of excess corticosterone on Leydig cell steroidogenesis are mediated through impaired glucose oxidation and defective NADPH generation. Co-administration of LH with corticosterone failed to prevent the decrease in serum testosterone and Leydig cell malic enzyme activity, suggesting the dominant inhibitory effects of excess corticosterone.