Nejvíce citovaný článek - PubMed ID 17949248
Comparison of the obesity phenotypes related to monosodium glutamate effect on arcuate nucleus and/or the high fat diet feeding in C57BL/6 and NMRI 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.
Alzheimer's disease (AD) is a progressive brain disorder characterized by extracellular amyloid-β (Aβ) plaques, intracellular neurofibrillary tangles formed by hyperphosphorylated Tau protein and neuroinflammation. Previous research has shown that obesity and type 2 diabetes mellitus, underlined by insulin resistance (IR), are risk factors for neurodegenerative disorders. In this study, obesity-induced peripheral and central IR and inflammation were studied in relation to AD-like pathology in the brains and periphery of APP/PS1 mice, a model of Aβ pathology, fed a high-fat diet (HFD). APP/PS1 mice and their wild-type controls fed either a standard diet or HFD were characterized at the ages of 3, 6 and 10 months by metabolic parameters related to obesity via mass spectroscopy, nuclear magnetic resonance, immunoblotting and immunohistochemistry to quantify how obesity affected AD pathology. The HFD induced substantial peripheral IR leading to central IR. APP/PS1-fed HFD mice had more pronounced IR, glucose intolerance and liver steatosis than their WT controls. The HFD worsened Aβ pathology in the hippocampi of APP/PS1 mice and significantly supported both peripheral and central inflammation. This study reveals a deleterious effect of obesity-related mild peripheral inflammation and prediabetes on the development of Aβ and Tau pathology and neuroinflammation in APP/PS1 mice.
- Klíčová slova
- APP/PS1, Alzheimer’s disease, amyloid-β, glucose intolerance, inflammation, insulin resistance, neuroinflammation, obesity, tau protein,
- MeSH
- Alzheimerova nemoc * etiologie MeSH
- amyloidní beta-protein MeSH
- diabetes mellitus 2. typu * MeSH
- dieta s vysokým obsahem tuků škodlivé účinky MeSH
- inzulinová rezistence * MeSH
- myši MeSH
- neurozánětlivé nemoci MeSH
- zánět MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- amyloidní beta-protein MeSH
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.
- Klíčová slova
- adipose tissue, food, metabolic disruptors, metabolic syndrome, obesity, obesogens, systematic low-grade inflammation,
- MeSH
- adipogeneze MeSH
- endokrinní disruptory * toxicita MeSH
- lidé MeSH
- obezita epidemiologie etiologie MeSH
- potraviny MeSH
- vystavení vlivu životního prostředí * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
- Názvy látek
- endokrinní disruptory * 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.
- Klíčová slova
- leptin resistance, obesity, prolactin-releasing peptide, rodent models, type 2 diabetes,
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
BACKGROUND: Obesity leads to low-grade inflammation in the adipose tissue and liver and neuroinflammation in the brain. Obesity-induced insulin resistance (IR) and neuroinflammation seem to intensify neurodegeneration including Alzheimer's disease. In this study, the impact of high-fat (HF) diet-induced obesity on potential neuroinflammation and peripheral IR was tested separately in males and females of THY-Tau22 mice, a model of tau pathology expressing mutated human tau protein. METHODS: Three-, 7-, and 11-month-old THY-Tau22 and wild-type males and females were tested for mobility, anxiety-like behavior, and short-term spatial memory in open-field and Y-maze tests. Plasma insulin, free fatty acid, cholesterol, and leptin were evaluated with commercial assays. Liver was stained with hematoxylin and eosin for histology. Brain sections were 3',3'-diaminobenzidine (DAB) and/or fluorescently detected for ionized calcium-binding adapter molecule 1 (Iba1), glial fibrillary acidic protein (GFAP), and tau phosphorylated at T231 (pTau (T231)), and analyzed. Insulin signaling cascade, pTau, extracellular signal-regulated kinase 1/2 (ERK1/2), and protein phosphatase 2A (PP2A) were quantified by western blotting of hippocampi of 11-month-old mice. Data are mean ± SEM and were subjected to Mann-Whitney t test within age and sex and mixed-effects analysis and Bonferroni's post hoc test for age comparison. RESULTS: Increased age most potently decreased mobility and increased anxiety in all mice. THY-Tau22 males showed impaired short-term spatial memory. HF diet increased body, fat, and liver weights and peripheral IR. HF diet-fed THY-Tau22 males showed massive Iba1+ microgliosis and GFAP+ astrocytosis in the hippocampus and amygdala. Activated astrocytes colocalized with pTau (T231) in THY-Tau22, although no significant difference in hippocampal tau phosphorylation was observed between 11-month-old HF and standard diet-fed THY-Tau22 mice. Eleven-month-old THY-Tau22 females, but not males, on both diets showed decreased synaptic and postsynaptic plasticity. CONCLUSIONS: Significant sex differences in neurodegenerative signs were found in THY-Tau22. Impaired short-term spatial memory was observed in 11-month-old THY-tau22 males but not females, which corresponded to increased neuroinflammation colocalized with pTau(T231) in the hippocampi and amygdalae of THY-Tau22 males. A robust decrease in synaptic and postsynaptic plasticity was observed in 11-month-old females but not males. HF diet caused peripheral but not central IR in mice of both sexes.
- Klíčová slova
- Alzheimer’s disease, Neuroinflammation, Obesity, Peripheral insulin resistance, Sex differences, THY-Tau22 mouse,
- MeSH
- dieta s vysokým obsahem tuků škodlivé účinky MeSH
- fosforylace MeSH
- hipokampus metabolismus MeSH
- inzulinová rezistence * MeSH
- krátkodobá paměť MeSH
- modely nemocí na zvířatech MeSH
- mozek metabolismus patofyziologie MeSH
- myši inbrední C57BL MeSH
- myši transgenní MeSH
- myši MeSH
- obezita komplikace etiologie MeSH
- omezení pohyblivosti MeSH
- proteiny tau MeSH
- sexuální faktory MeSH
- stárnutí metabolismus MeSH
- tauopatie komplikace genetika MeSH
- zánět MeSH
- ztučnělá játra metabolismus patologie MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- myši MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- MAPT protein, human MeSH Prohlížeč
- proteiny tau 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.
- Klíčová slova
- ghrelin, glucagon-like peptide-1, leptin, non-alcoholic steatohepatitis, peptides,
- MeSH
- hypoglykemika farmakologie MeSH
- lidé MeSH
- modely nemocí na zvířatech * MeSH
- nealkoholová steatóza jater farmakoterapie etiologie patofyziologie MeSH
- peptidové fragmenty farmakologie MeSH
- přijímání potravy * MeSH
- progrese nemoci MeSH
- regulace chuti k jídlu účinky léků MeSH
- zánět komplikace MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
- Názvy látek
- hypoglykemika MeSH
- peptidové fragmenty MeSH
Prolactin-releasing peptide (PrRP) belongs to the large RF-amide neuropeptide family with a conserved Arg-Phe-amide motif at the C-terminus. PrRP plays a main role in the regulation of food intake and energy expenditure. This review focuses not only on the physiological functions of PrRP, but also on its pharmacological properties and the actions of its G-protein coupled receptor, GPR10. Special attention is paid to structure-activity relationship studies on PrRP and its analogs as well as to their effect on different physiological functions, mainly their anorexigenic and neuroprotective features and the regulation of the cardiovascular system, pain, and stress. Additionally, the therapeutic potential of this peptide and its analogs is explored.
- Klíčová slova
- GPR10, RF-amide peptides, energy expenditure, food intake regulation, neuroprotection, prolactin-releasing peptide, signaling,
- MeSH
- energetický metabolismus účinky léků MeSH
- hormon uvolňující prolaktin chemie metabolismus farmakologie MeSH
- lidé MeSH
- neurodegenerativní nemoci farmakoterapie patologie MeSH
- neuroprotektivní látky chemie farmakologie terapeutické užití MeSH
- přijímání potravy účinky léků MeSH
- receptory spřažené s G-proteiny chemie genetika metabolismus MeSH
- signální transdukce účinky léků MeSH
- vztahy mezi strukturou a aktivitou MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
- Názvy látek
- hormon uvolňující prolaktin MeSH
- neuroprotektivní látky MeSH
- PRLHR protein, human MeSH Prohlížeč
- receptory spřažené s G-proteiny MeSH
PURPOSE: Consumption of dietary supplements with green tea extract (GTE) is popular for weight management, but it may be accompanied by various side effects, including interactions with drugs. The aim of the present in vivo study was to evaluate the effect of defined GTE (Polyphenon 60) in three dosage schemes on insulin, leptin and drug-metabolizing enzymes in obese mice. METHODS: Experimental obesity was induced by repeated s.c. application of monosodium glutamate to newborn mice. Green tea extract was administered in three dosage schemes in chow diet. The plasmatic levels of insulin and leptin were assayed using enzyme-linked immunosorbent assay. Enzyme activities and mRNA expressions of drug-metabolizing enzymes (totally 13) were analyzed in liver and small intestine using spectrophotometric and HPLC assays and RT-PCR, respectively. RESULTS: GTE-treatment decreased insulin and leptin levels. Eleven enzymes were significantly affected by GTE-treatment. Long-term administration of 0.01% GTE caused increase in the activity and mRNA level of cytochrome P450 3A4 (CYP3A4) ortholog in the liver as well as in the small intestine. Interestingly, short-term overdose by GTE (0.1%) had more pronounced effects on enzyme activities and mRNA expressions than long-term overdose. CONCLUSIONS: GTE-mediated induction of CYP3A4 ortholog, the main drug-metabolizing enzyme, could result in decreased efficacy of simultaneously or subsequently administered drug in obese individuals.
- Klíčová slova
- Catechins, Drug-metabolizing enzymes, Green tea extract, Metabolic syndrome, Obesity,
- MeSH
- antioxidancia farmakologie MeSH
- aromatické hydroxylasy genetika metabolismus MeSH
- čaj chemie MeSH
- cytochrom P-450 CYP2E1 genetika metabolismus MeSH
- cytochrom P-450 CYP3A genetika metabolismus MeSH
- ELISA MeSH
- glutamát sodný škodlivé účinky MeSH
- inzulin krev MeSH
- játra účinky léků metabolismus MeSH
- leptin krev MeSH
- messenger RNA genetika metabolismus MeSH
- modely nemocí na zvířatech MeSH
- myši obézní MeSH
- myši MeSH
- obezita chemicky indukované farmakoterapie MeSH
- potravní doplňky * MeSH
- rodina 2 cytochromů P450 MeSH
- rostlinné extrakty farmakologie MeSH
- vztah mezi dávkou a účinkem léčiva MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- antioxidancia MeSH
- aromatické hydroxylasy MeSH
- čaj MeSH
- Cyp2a5 protein, mouse MeSH Prohlížeč
- cytochrom P-450 CYP2E1 MeSH
- cytochrom P-450 CYP3A MeSH
- cytochrome P450 3A4, mouse MeSH Prohlížeč
- glutamát sodný MeSH
- inzulin MeSH
- leptin MeSH
- messenger RNA MeSH
- rodina 2 cytochromů P450 MeSH
- rostlinné extrakty MeSH