Colonic dysmotility associated with high-fat diet-induced obesity: Role of enteric glia.
- 作者列表："Antonioli L","D'Antongiovanni V","Pellegrini C","Fornai M","Benvenuti L","di Carlo A","van den Wijngaard R","Caputi V","Cerantola S","Giron MC","Németh ZH","Haskó G","Blandizzi C","Colucci R
:The present study was designed to examine the role of enteric glial cells (EGCs) in colonic neuromuscular dysfunctions in a mouse model of high-fat diet (HFD)-induced obesity. C57BL/6J mice were fed with HFD or standard diet (SD) for 1, 2, or 8 weeks. Colonic interleukin (IL)-1β, IL-6, and malondialdehyde (MDA) levels were measured. Expression of occludin in colonic tissues was examined by western blot. Substance P (SP), S100β, GFAP, and phosphorylated mitogen-activated protein kinase 1 (pERK) were assessed in whole mount specimens of colonic plexus by immunohistochemistry. Colonic tachykininergic contractions, elicited by electrical stimulation or exogenous SP, were recorded in the presence or absence of fluorocitrate (FC). To mimic exposure to HFD, cultured EGCs were incubated with palmitate (PA) and/or lipopolysaccharide (LPS). SP and IL-1β levels were assayed in the culture medium by ELISA. HFD mice displayed an increase in colonic IL-1β and MDA, and a reduction of occludin at week 2. These changes occurred to a greater extent at week 8. In vitro electrically evoked tachykininergic contractions were enhanced in HFD mice after 2 or 8 weeks, and they were blunted by FC. Colonic IL-6 levels as well as substance P and S100β density in myenteric ganglia of HFD mice were increased at week 8, but not at week 1 or 2. In cultured EGCs, co-incubation with palmitate plus LPS led to a significant increase in both SP and IL-1β release. HFD-induced obesity is characterized by a hyperactivation of EGCs and is involved in the development of enteric motor disorders through an increase in tachykininergic activity and release of pro-inflammatory mediators.
本研究旨在检测肠胶质细胞 (EGCs) 在高脂饮食 (HFD) 诱导的肥胖小鼠模型中的结肠神经肌肉功能障碍中的作用。C57BL/6J 小鼠用 HFD 或标准饮食 (SD) 喂养 1 、 2 或 8 周。测定结肠白细胞介素 (IL)-1 β 、 IL-6 和丙二醛 (MDA) 水平。Western blot 检测结肠组织中 occludin 的表达。通过免疫组织化学方法对整个结肠丛标本进行 P 物质 (SP) 、 s100 β 、 GFAP 和磷酸化丝裂原活化蛋白激酶 1 (pERK) 评估。在存在或不存在氟代柠檬酸 (FC) 的情况下记录电刺激或外源性 SP 引起的结肠快速激肽能收缩。为了模拟 HFD 的暴露，将培养的 EGCs 与棕榈酸盐 (PA) 和/或脂多糖 (LPS) 孵育。用 ELISA 法测定培养基中 SP 和 il-1 β 水平。HFD 小鼠在第 2 周显示结肠 il-1 β 和 MDA 增加，occludin 减少。这些变化在第 8 周发生的程度更大。 HFD 小鼠 2 周或 8 周后体外电诱发的速激肽能收缩增强，FC 使其钝化。HFD 小鼠结肠 IL-6 水平以及肌间神经节内 p物质和 s100 β 密度在第 8 周时增加，但在第 1 周或第 2 周时不增加。在培养的 EGCs 中，棕榈酸盐加 LPS 共同孵育导致 SP 和 il-1 β 释放显著增加。HFD 诱导的肥胖以 EGCs 过度激活为特征，通过速激肽活性的增加和促炎介质的释放参与肠道运动障碍的发展。
METHODS:Maintaining adequate daily protein intake is important to maintain muscle mass throughout the lifespan. In this regard, the overnight period has been identified as a window of opportunity to increase protein intake in the elderly. However, it is unknown whether pre-sleep protein intake affects next-morning appetite and, consequently, protein intake. Therefore, the purpose of the current study was to investigate the effects of a pre-sleep protein drink on next-morning appetite, energy intake and metabolism. Twelve older individuals (eight males, four females; age: 71.3 ± 4.2 years) took part in a single-blind randomised cross-over study. After a standardised dinner, participants consumed either a 40-g protein drink, isocaloric maltodextrin drink, or placebo water control before bedtime. Next-morning appetite, energy intake, resting metabolic rate (RMR), respiratory exchange rate (RER), and plasma acylated ghrelin, leptin, glucose, and insulin concentrations were assessed. No between-group differences were observed for appetite and energy intake at breakfast. Furthermore, RMR, RER, and assessed blood markers were not significantly different between any of the treatment groups. Pre-sleep protein intake does not affect next-morning appetite and energy intake and is therefore a viable strategy to increase daily protein intake in an older population.
METHODS:Leptin (LEP) regulates glucose metabolism and energy storage in the body. Osteoarthritis (OA) is associated with the upregulation of serum LEP. LEP promoter methylation is associated with obesity. So far, few studies have explored the association of BMI and OA with LEP methylation. We assessed the interaction between body mass index (BMI) and OA on LEP promoter methylation. Data of 1114 participants comprising 583 men and 558 women, aged 30−70 years were retrieved from the Taiwan Biobank Database (2008−2015). Osteoarthritis was self-reported and cases were those who reported having ever been clinically diagnosed with osteoarthritis. BMI was categorized into underweight, normal weight, overweight, and obesity. The mean LEP promoter methylation level in individuals with osteoarthritis was 0.5509 ± 0.00437 and 0.5375 ± 0.00101 in those without osteoarthritis. The interaction between osteoarthritis and BMI on LEP promoter methylation was significant (p-value = 0.0180). With normal BMI as the reference, the mean LEP promoter methylation level was significantly higher in obese osteoarthritic individuals (β = 0.03696, p-value = 0.0187). However, there was no significant association between BMI and LEP promoter methylation in individuals without osteoarthritis, regardless of BMI. In conclusion, only obesity was significantly associated with LEP promoter methylation (higher levels) specifically in osteoarthritic patients.
METHODS:Background For the same BMI, South Asians have a higher body fat percentage, a higher liver fat content and a more adverse metabolic profile than whites. South Asians may have a lower fat oxidation than whites, which could result in an unfavorable metabolic profile when exposed to increased high-fat foods consumption and decreased physical activity as in current modern lifestyle. Objective To determine substrate partitioning, liver fat accumulation and metabolic profile in South Asian and white men in response to overfeeding with high-fat diet under sedentary conditions in a respiration chamber. Design Ten South Asian men (BMI, 18–29 kg/m^2) and 10 white men (BMI, 22–33 kg/m^2), matched for body fat percentage, aged 20–40 year were included. A weight maintenance diet (30% fat, 55% carbohydrate, and 15% protein) was given for 3 days. Thereafter, a baseline measurement of liver fat content (1H-MRS) and blood parameters was performed. Subsequently, subjects were overfed (150% energy requirement) with a high-fat diet (60% fat, 25% carbohydrate, and 15% protein) over 3 consecutive days while staying in a respiration chamber mimicking a sedentary lifestyle. Energy expenditure and substrate use were measured for 3 × 24-h. Liver fat and blood parameters were measured again after the subjects left the chamber. Results The 24-h fat oxidation as a percentage of total energy expenditure did not differ between ethnicities ( P = 0.30). Overfeeding increased liver fat content ( P = 0.02), but the increase did not differ between ethnicities ( P = 0.64). In South Asians, overfeeding tended to increase LDL-cholesterol ( P = 0.08), tended to decrease glucose clearance ( P = 0.06) and tended to elevate insulin response ( P = 0.07) slightly more than whites. Conclusions Despite a similar substrate partitioning and similar accretion of liver fat, overfeeding with high-fat under sedentary conditions tended to have more adverse effects on the lipid profile and insulin sensitivity in South Asians.