Vagotomy Reduces Insulin Clearance in Obese Mice Programmed by Low-Protein Diet in the Adolescence

Effects of double burden malnutrition on energetic metabolism and glycemic homeostasis: A narrative review

Rapid changes in the food process led to greater consumption of ultra-processed foods which, associated with reduced physical activity, increased the number of overweight and obese individuals worldwide. However, in low and middle-income countries (LMICS) the growth of the obesity epidemic took place despite the high prevalence of undernutrition in children. This generated the coexistence of these two nutritional patterns, currently defined as double burden malnutrition (DBM). Several reports have already described the social, political, and economic aspects related to the causes and possible solutions for the control of DBM. Here, we highlight the metabolic alterations, related to fat deposition and glycemic homeostasis, described in experimental models of DBM and the differential effects of therapeutic strategies already tested. Therefore, this work aims to help the scientific community to understand how the DBM can lead to the development of obesity and type 2 diabetes through different mechanisms from traditional models of obesity and highlights the need to study these mechanisms and new therapeutic strategies to improve damages caused by DBM.

Green tea polyphenols attenuate hepatic steatosis, and reduce insulin resistance and inflammation in high-fat diet-induced rats

Non‑alcoholic fatty liver disease (NAFLD) is characterized by hepatic steatosis, insulin resistance and inflammation; however, the exact pathogenesis of NAFLD is not fully understood. Green tea polyphenols (GTP) exhibit beneficial effects against metabolic syndrome. However, the effect of GTP on NAFLD remains largely unknown. The aim of the present study was to investigate the effects of GTP on NAFLD in high‑fat diet (HFD)‑induced rats. The NAFLD rat model was induced with a HFD for 8 weeks. A total of 30 adult male Sprague Dawley rats were randomly divided into three groups: i) Normal control group; ii) HFD group; and iii) HFD with GTP group. Hematoxylin and eosin and Oil Red O analyses were performed. The levels of alanine aminotransferase (ALT), aspartate amino-transferase (AST) and inflammatory cytokines in the serum, as well as oxidative stress markers and hepatic lipids in the liver were measured. In addition, parameters associated with glucose metabolism were also assessed. Western blotting and RT‑qPCR were used to determine the expression levels of 5' adenosine monophosphate‑activated protein kinase (AMPK). HFD‑induced rats exhibited features associated with NAFLD. GTP intervention significantly reduced serum ALT and AST levels. Fasting serum glucose, insulin resistance and hepatic lipid levels were all decreased in the GTP‑treated rats. GTP also significantly decreased the levels of TNF‑α, IL‑6 and malondialdehyde. In contrast, superoxide dismutase levels were increased in the liver. Furthermore, GTP also significantly increased phosphorylation of AMPK and attenuated histopathological changes indicative of injury in liver tissue. GTP has a protective effect on HFD‑induced hepatic steatosis, insulin resistance and inflammation, and the underlying mechanism may involve the AMPK pathway.

β cells can be generated from cytokeratin 5-positive cells after cerulein-induced pancreatitis in adult mice

Clinical studies have revealed that some patients will develop glucose tolerance dysfunction after recovering from acute pancreatitis (AP), which indicated the importance of investigating the potential therapies for restoration of islet β cell function. Cytokeratin 5 (Krt5)-positive cells are considered to function as stem or progenitor cells in the regeneration of lung and salivary gland following injury. In the present study, AP was induced by six hourly intraperitoneal injections of 100 μg/kg cerulein for 4 consecutive days in adult mice, in order to determine the role of Krt5-positive cells in pancreatic regeneration, especially in the restoration of β cell function and the underlying mechanisms. Results showed that glucose homeostasis were deteriorated partly during the recovery process after AP. Furthermore, clusters of Krt5-positive cells were significantly increased in the damaged pancreas marked by inflammatory cells infiltration and acinar cell eradication. In addition, cells co-labelling insulin and Krt5 were found in the injured region after cerulein administration, part of these cells were immunopositive for GLUT2. Taken together, our data demonstrated that Krt5-expressing cells could be involved in the natural pancreas self-healing process and the renewal of β cells after AP in adult mice. It is promising that promoting conversion of Krt5-expressing cells into functional β cells may be a novel method to mitigate the development of diabetes mellitus after AP in vivo.