Most cited article - PubMed ID 16782213
Effect of cholecystokinin on feeding is attenuated in monosodium glutamate obese mice
Metabolic dysfunction-associated steatotic liver disease (MASLD), one of the leading causes of chronic liver disorders, is characterized by hepatic lipid accumulation. MASLD causes alterations in the antioxidant defense system, lipid, and drug metabolism, resulting in impaired antioxidant status, hepatic metabolic processes, and clearance of therapeutic drugs, respectively. In the MASLD pathogenesis, dysregulated epigenetic mechanisms (e.g., histone modifications, DNA methylation, microRNAs) play a substantial role. In this study, the development of MASLD was investigated in mice fed a high-fat, high-fructose, and high-cholesterol (FFC) diet from 2 months of age, mice treated neonatally with monosodium glutamate (MSG) on a standard diet (STD), and mice treated with MSG on an FFC diet at 7 months of age and compared to control mice (C) on STD. Changes in liver histology, detoxification enzymes, epigenetic regulation, and genes involved in lipid metabolism were characterized and compared. The strong liver steatosis was observed in MSG STD, C FFC, and MSG FFC, with significant fibrosis in the latter one. Moreover, substantial alterations in hepatic lipid metabolism, epigenetic regulatory factors, and expressions and activities of various detoxification enzymes (namely superoxide dismutase, catalase, and carbonyl reductase 1) were observed in MASLD mice compared to control mice. miR-200b-3p, highly significantly upregulated in both FFC groups, could be considered as a potential diagnostic marker of MASLD. The MSG mice fed FFC seem to be a suitable model of MASLD characterized by both liver steatosis and fibrosis and substantial metabolic dysregulation.
Obesogens, as environmental endocrine-disrupting chemicals, are supposed to have had an impact on the prevalence of rising obesity around the world over the last forty years. These chemicals are probably able to contribute not only to the development of obesity and metabolic disturbances in individuals, but also in their progeny, having the capability to epigenetically reprogram genetically inherited set-up points for body weight and body composition control during critical periods of development, such as fetal, early life, and puberty. In individuals, they may act on myriads of neuro-endocrine-immune metabolic regulatory pathways, leading to pathophysiological consequences in adipogenesis, lipogenesis, lipolysis, immunity, the influencing of central appetite and energy expenditure regulations, changes in gut microbiota-intestine functioning, and many other processes. Evidence-based medical data have recently brought much more convincing data about associations of particular chemicals and the probability of the raised risk of developing obesity. Foods are the main source of obesogens. Some obesogens occur naturally in food, but most are environmental chemicals, entering food as a foreign substance, whether in the form of contaminants or additives, and they are used in a large amount in highly processed food. This review article contributes to a better overview of obesogens, their occurrence in foods, and their impact on the human organism.
- Keywords
- adipose tissue, food, metabolic disruptors, metabolic syndrome, obesity, obesogens, systematic low-grade inflammation,
- MeSH
- Adipogenesis MeSH
- Endocrine Disruptors * toxicity MeSH
- Humans MeSH
- Obesity epidemiology etiology MeSH
- Food MeSH
- Environmental Exposure * MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Review MeSH
- Names of Substances
- Endocrine Disruptors * MeSH
Obesity and type 2 diabetes mellitus (T2DM) are preconditions for the development of metabolic syndrome, which is reaching pandemic levels worldwide, but there are still only a few anti-obesity drugs available. One of the promising tools for the treatment of obesity and related metabolic complications is anorexigenic peptides, such as prolactin-releasing peptide (PrRP). PrRP is a centrally acting neuropeptide involved in food intake and body weight (BW) regulation. In its natural form, it has limitations for peripheral administration; thus, we designed analogs of PrRP lipidized at the N-terminal region that showed high binding affinities, increased stability and central anorexigenic effects after peripheral administration. In this review, we summarize the preclinical results of our chronic studies on the pharmacological role of the two most potent palmitoylated PrRP31 analogs in various mouse and rat models of obesity, glucose intolerance, and insulin resistance. We used mice and rats with diet-induced obesity fed a high-fat diet, which is considered to simulate the most common form of human obesity, or rodent models with leptin deficiency or disrupted leptin signaling in which long-term food intake regulation by leptin is distorted. The rodent models described in this review are models of metabolic syndrome with different severities, such as obesity or morbid obesity, prediabetes or diabetes and hypertension. We found that the effects of palmitoylated PrRP31 on food intake and BW but not on glucose intolerance require intact leptin signaling. Thus, palmitoylated PrRP31 analogs have potential as therapeutics for obesity and related metabolic complications.
- Keywords
- leptin resistance, obesity, prolactin-releasing peptide, rodent models, type 2 diabetes,
- Publication type
- Journal Article MeSH
- Review MeSH
Obesity, diabetes, insulin resistance, sedentary lifestyle, and Western diet are the key factors underlying non-alcoholic fatty liver disease (NAFLD), one of the most common liver diseases in developed countries. In many cases, NAFLD further progresses to non-alcoholic steatohepatitis (NASH), fibrosis, cirrhosis, and to hepatocellular carcinoma. The hepatic lipotoxicity and non-liver factors, such as adipose tissue inflammation and gastrointestinal imbalances were linked to evolution of NAFLD. Nowadays, the degree of adipose tissue inflammation was shown to directly correlate with the severity of NAFLD. Consumption of higher caloric intake is increasingly emerging as a fuel of metabolic inflammation not only in obesity-related disorders but also NAFLD. However, multiple causes of NAFLD are the reason why the mechanisms of NAFLD progression to NASH are still not well understood. In this review, we explore the role of food intake regulating peptides in NAFLD and NASH mouse models. Leptin, an anorexigenic peptide, is involved in hepatic metabolism, and has an effect on NAFLD experimental models. Glucagon-like peptide-1 (GLP-1), another anorexigenic peptide, and GLP-1 receptor agonists (GLP-1R), represent potential therapeutic agents to prevent NAFLD progression to NASH. On the other hand, the deletion of ghrelin, an orexigenic peptide, prevents age-associated hepatic steatosis in mice. Because of the increasing incidence of NAFLD and NASH worldwide, the selection of appropriate animal models is important to clarify aspects of pathogenesis and progression in this field.
- Keywords
- ghrelin, glucagon-like peptide-1, leptin, non-alcoholic steatohepatitis, peptides,
- MeSH
- Hypoglycemic Agents pharmacology MeSH
- Humans MeSH
- Disease Models, Animal * MeSH
- Non-alcoholic Fatty Liver Disease drug therapy etiology physiopathology MeSH
- Peptide Fragments pharmacology MeSH
- Eating * MeSH
- Disease Progression MeSH
- Appetite Regulation drug effects MeSH
- Inflammation complications MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Review MeSH
- Names of Substances
- Hypoglycemic Agents MeSH
- Peptide Fragments MeSH
BACKGROUND: CART (cocaine- and amphetamine-regulated transcript) peptide and cholecystokinin (CCK) are neuromodulators involved in feeding behavior. This study is based on previously found synergistic effect of leptin and CCK on food intake and our hypothesis on a co-operation of the CART peptide and CCK in food intake regulation and Fos activation in their common targets, the nucleus tractus solitarii of the brainstem (NTS), the paraventricular nucleus (PVN), and the dorsomedial nucleus (DMH) of the hypothalamus. RESULTS: In fasted C57BL/6 mice, the anorexigenic effect of CART(61-102) in the doses of 0.1 or 0.5 microg/mouse was significantly enhanced by low doses of CCK-8 of 0.4 or 4 microg/kg, while 1 mg/kg dose of CCK-A receptor antagonist devazepide blocked the effect of CART(61-102) on food intake. After simultaneous administration of 0.1 microg/mouse CART(61-102) and of 4 microg/kg of CCK-8, the number of Fos-positive neurons in NTS, PVN, and DMH was significantly higher than after administration of each particular peptide. Besides, CART(61-102) and CCK-8 showed an additive effect on inhibition of the locomotor activity of mice in an open field test. CONCLUSION: The synergistic and long-lasting effect of the CART peptide and CCK on food intake and their additive effect on Fos immunoreactivity in their common targets suggest a co-operative action of CART peptide and CCK which could be related to synergistic effect of leptin on CCK satiety.
- MeSH
- Hormone Antagonists pharmacology MeSH
- Benzodiazepinones pharmacology MeSH
- Devazepide pharmacology MeSH
- Phenylurea Compounds pharmacology MeSH
- Thinness * MeSH
- Injections, Intraperitoneal MeSH
- Injections, Intraventricular MeSH
- Cocaine- and Amphetamine-Regulated Transcript Protein MeSH
- Mice, Inbred C57BL MeSH
- Mice MeSH
- Neurons drug effects metabolism MeSH
- Dorsomedial Hypothalamic Nucleus drug effects physiology MeSH
- Paraventricular Hypothalamic Nucleus drug effects physiology MeSH
- Solitary Nucleus drug effects physiology MeSH
- Exploratory Behavior drug effects physiology MeSH
- Peptide Fragments pharmacology MeSH
- Nerve Tissue Proteins pharmacology MeSH
- Proto-Oncogene Proteins c-fos metabolism MeSH
- Receptor, Cholecystokinin A antagonists & inhibitors MeSH
- Receptor, Cholecystokinin B antagonists & inhibitors MeSH
- Appetite Regulation drug effects physiology MeSH
- Sincalide pharmacology MeSH
- Drug Synergism MeSH
- Dose-Response Relationship, Drug MeSH
- Animals MeSH
- Check Tag
- Male MeSH
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Names of Substances
- Hormone Antagonists MeSH
- Benzodiazepinones MeSH
- Devazepide MeSH
- Phenylurea Compounds MeSH
- Cocaine- and Amphetamine-Regulated Transcript Protein MeSH
- L 365260 MeSH Browser
- Peptide Fragments MeSH
- Nerve Tissue Proteins MeSH
- Proto-Oncogene Proteins c-fos MeSH
- Receptor, Cholecystokinin A MeSH
- Receptor, Cholecystokinin B MeSH
- Sincalide MeSH