leptin and Gastroenteritis

Obesity is an important public health problem worldwide. It increases the risk of many chronic diseases such as diabetes and cardiovascular diseases. Meanwhile, obesity is a major risk factor for several types of cancer including gastric cancer. Possible mechanisms linking obesity with gastric cancer may include obesity associated gastro-oesophageal reflux, insulin resistance, altered levels of adiponectin, leptin, ghrelin, and an abnormally increased blood level of insulin-like growth factor (IGF). Helicobacter pylori (H. pylori) infection is a well-recognized risk factor for peptic ulcer and gastric cancer. Recent studies have revealed an increased prevalence of H. pylori infection in obese patients, providing another clue for the increased incidence of gastric cancer in obese population. If this connection can be confirmed in animal models and a large cohort of patients, then eradicating H. pylori together with life style modification in obese individuals may help prevent the development of gastric cancer in the increasingly obese population.

Topics: Adiponectin; Animals; Gastroenteritis; Gastroesophageal Reflux; Ghrelin; Helicobacter Infections; Helicobacter pylori; Humans; Inflammation; Insulin Resistance; Insulin-Like Growth Factor I; Leptin; Obesity; Risk Factors; Signal Transduction; Stomach Neoplasms

Infectious disease is the major cause of morbidity and mortality in developing countries, particularly in children. Increasing evidence suggests that protein-calorie malnutrition is the underlying reason for the increased susceptibility to infections observed in these areas. Moreover, certain infectious diseases also cause malnutrition, which can result in a vicious cycle. Malnutrition and bacterial gastrointestinal and respiratory infections represent a serious public health problem. The increased incidence and severity of infections in malnourished children is largely due to the deterioration of immune function; limited production and/or diminished functional capacity of all cellular components of the immune system have been reported in malnutrition. In this review, we analyze the cyclical relationship between malnutrition, immune response dysfunction, increased susceptibility to infectious disease, and metabolic responses that further alter nutritional status. The consequences of malnutrition are diverse and included: increased susceptibility to infection, impaired child development, increased mortality rate and individuals who come to function in suboptimal ways.

Topics: Animals; Bacterial Infections; Child; Child Nutrition Disorders; Gastroenteritis; Humans; Leptin; Nutritional Status; Respiratory Tract Infections

Ghrelin and leptin are newly discovered, still very mysterious, hormones. Beside the energy balance, they regulate endocrine and immune system, growth and maturate processes. Fluctuations of both hormones concentration are observed in many gastrointestinal tract diseases. In this publication is presented current knowledge about meaning ghrelin and leptin in choosen diseases, like malabsorption syndromes, inflammatory diseases and tumors of gastrointestinal tract.

Topics: Energy Metabolism; Gastroenteritis; Gastrointestinal Diseases; Gastrointestinal Tract; Ghrelin; Helicobacter Infections; Helicobacter pylori; Humans; Leptin

Besides being mandatory in the metabolic system, adipokines like leptin directly affect immunity. Leptin was found to be necessary in T helper 1 (Th1)-dependent inflammatory processes, whereas effects on Th2 cells are rarely understood. Here, we focused on leptin in T-helper cell polarization and in Th2-mediated intestinal inflammation in vivo. The induction of cytokine-producing Th1 or Th2 cells from naive CD4(+) T cells under polarizing conditions in vitro was generally decreased in cells from leptin-deficient ob/ob mice compared with wild-type mice. To explore the in vivo relevance of leptin in Th2-mediated inflammation, the model of oxazolone-induced colitis was employed in wild-type, ob/ob, and leptin-reconstituted ob/ob mice. Ob/ob mice were protected, whereas wild-type and leptin-reconstituted ob/ob mice developed colitis. The disease severity went in parallel with local production of the Th2 cytokine IL-13. A possible explanation for the protection of ob/ob mice in Th1- as well as in Th2-dependent inflammation is provided by a decreased expression of the key transcription factors for Th1 and Th2 polarization, T-bet and GATA-3, in naive ob/ob T cells. In conclusion, these results support the regulatory function of the adipokine leptin within T-cell polarization and thus in the acquired immune system and support the concept that there is a close interaction with the endocrine system.

Topics: Animals; Apoptosis; CD4-Positive T-Lymphocytes; Cell Polarity; Cell Proliferation; Cells, Cultured; Female; Gastroenteritis; GATA3 Transcription Factor; Gene Expression Regulation; Leptin; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mice, Obese; Receptors, Leptin; T-Box Domain Proteins