Bariatric Surgery in Rats Upregulates FSP27 Expression in Fat Tissue to Affect Fat Hydrolysis and Metabolism

Purpose

To explore the changes in FSP27 expression and fat metabolism in adipose tissue and their relationship after bariatric surgery in rats.

Method

Food intake, body weight, triglyceride content, fat distribution, and fat cell morphology were evaluated in rats grouped into control, sham, sleeve gastrectomy (SG), and Roux-en-Y gastric bypass (RYGB) groups. Immunohistochemistry and western blotting were used to detect protein expression and real-time PCR was used to detect mRNA expression. Mouse 3T3-L1 preadipocytes were used to assess the effects of different energy levels and nutrient factors on FSP27 in adipocytes.

Result

Food intake, body weight, and triglyceride levels were reduced in RYGB and SG rats within 28 days after surgery, with a more pronounced effect in the RYGB group. Weight loss was mainly due to loss of fat mass rather than loss of lean mass, with the most pronounced decrease in trunk fat. FSP27 expression increased in lean rat adipocytes accompanied by increased lipid droplets (LDs). In SG and RYGB rats, the FSP27 protein concentration gradually increased in white adipose tissue (WAT) after operation. Hormone-sensitive lipase (HSL), p-HSL/HSL, Adipose Triglyceride Lipase (ATGL), and Comparative Gene Identification-58 (CGI-58) gradually decreased in SG and RYGB rats, but they were always higher than in control and sham animals. FSP27 was also decreased in 3T3-L1 adipocytes of animals with a high-energy diet.

Conclusion

FSP27 is associated with rat lipid metabolism and its expression varies with energy and nutrient supply. It can inhibit excessive hydrolysis and fat accumulation by regulating HSL and ATGL expression and by mediating LDs formation.

Raspberry ketone preserved cholinergic activity and antioxidant defense in obesity induced Alzheimer disease in rats

Obesity is a proven risk factor for neurodegenerative disease like Alzheimer's disease (AD). Accumulating evidences suggested that nutritional interventions provide potential for prevention and treatment of AD. The present study aimed to investigate the effect of dietary treatment of obese rats with natural Raspberry ketone (RK) and their relationship with neurodegeneration. Obesity was first induced in 40 male Wistar rats (140-160 g) by feeding high fat diet (HFD) for 16 weeks. Obese rats were then assigned into 4 groups (n = 10 each). (O-AD) is obese induced AD group maintained on HFD for another 6 weeks. OCR is obese group received calorie restricted diet for 6 weeks. OCRRK is obese group received calorie restricted diet and RK (44 mg/kg body weight, daily, orally) for 6 weeks and OCRD is obese group received calorie restricted diet and orlistate (10 mg/kg body weight, daily orally) for 6 weeks. Another 10 normal rats received normal diet were used as normal control group (NC). Body weight, visceral white adipose tissue weight (WAT), lipid profile, oxidative stress markers, adiponectin, cholinergic activity and amyloid extracellular plaques were examined. In addition to histological changes in brain tissues were evaluated.Raspberry ketone (RK) via its antioxidant properties attenuated oxidative damage and dyslipidemia in O-AD group. It inhibited acetylcholinesterase enzyme (AchE) and hence increased acetylcholine level (Ach) in brain tissues of O-AD rats. It is also impeded the upregulation of beta-secretase-1 (BACE-1) and the accumulation of amyloid beta (Aβ) plaques which crucially involved in AD. The combination of CR diet with RK was more effective than CR diet with orlistate (antiobese drug) in abrogating the neurodegenerative changes induced by obesity. Results from this study suggested that concomitant supplementation of RK with calorie restricted regimen effectively modulate the neurodegenerative changes induced by obesity and delay the progression of AD.

The role of expression imbalance between adipose synthesis and storage mediated by PPAR-γ/FSP27 in the formation of insulin resistance in catch up growth

Background

Catch up growth (CUG) motivated by under-nutrition can lead to insulin resistance (IR) and visceral fat over-accumulation. However, the precise mechanisms on IR induced by adipose tissue changes during CUG remain unresolved.

Methods

Experimental rats were divided into three groups: normal chow group, catch up growth group and resveratrol administrated group. The whole experiment was carried out in four stages: 4, 6, 8 and 12 weeks.

Peroxisome-proliferator activated receptor gamma (PPAR-γ) and fat-specific protein 27 (FSP27) expression level in epididymal adipose tissues (EAT) and subcutaneous adipose tissues (SAT) were detected along with other IR indicators.

Results

Calorie restriction (CR) significantly increased PPAR-γ expression in EAT while decreased FSP27 expression. During re-feeding, both of the expression of PPAR-γ and FSP27 increased, even FSP27 returned to normal level when CUG for 4 weeks. Although PPAR-γ expression declined slightly at 8 weeks, it was still much stronger than normal chow groups. However, no changes were seen in SAT. Relative insufficiency of FSP27 expression in EAT results in a decrease in lipid storage capacity, causing a series of path physiological changes that led to the formation of IR. Resveratrol inhibited the expression of PPAR-γ and promoted FSP27 expression, thus fundamentally improving IR.

Conclusions

The imbalance between adipose synthesis and storage mediated by PPAR-γ / FSP27 in the EAT plays a pivotal role in the formation of IR during CUG. Resveratrol can correct fat formation and storage imbalance status by up-regulating FSP27 and down-regulating PPAR-γ expression level, ameliorating insulin sensitivity.

Efficacy of phytosterols and fish-oil supplemented high-oleic-sunflower oil rich diets in hypercholesterolemic growing rats

Phytosterols (P) and fish-oil (F) efficacy on high-oleic-sunflower oil (HOSO) diets were assessed in hypercholesterolemic growing rats. Controls (C) received a standard diet for 8 weeks; experimental rats were fed an atherogenic diet (AT) for 3 weeks, thereafter were divided into four groups fed for 5 weeks a monounsaturated fatty acid diet (MUFA) containing either: extra virgin olive oil (OO), HOSO or HOSO supplemented with P or F. The diets did not alter body weight or growth. HOSO-P and HOSO-F rats showed reduced total cholesterol (T-chol), non-high-density lipoprotein-cholesterol (non-HDL-chol) and triglycerides and increased HDL-chol levels, comparably to the OO rats. Total body fat (%) was similar among all rats; but HOSO-F showed the lowest intestinal, epididymal and perirenal fat. However, bone mineral content and density, and bone yield stress and modulus of elasticity were unchanged. Growing hypercholesterolemic rats fed HOSO with P or F improved serum lipids and fat distribution, but did not influence material bone quality.

Danhong Huayu Koufuye combined with metformin attenuated diabetic retinopathy in Zucker diabetic fatty rats

AIM

To evaluate effects of Danhong Huayu Koufuye (DHK, a Chinese medicinal formulae) alone or combined with metformin on diabetic retinopathy (DR) in Zucker diabetic fatty (ZDF) rats, an animal model of obese type-2 diabetes, and then to investigate the mechanisms.

METHODS

ZDF (fa/fa) rats were administered with vehicle (distilled water), metformin, DHK, and DHK plus metformin. Electrophysiological and histological analysis were applied to evaluated effects of DHK alone or combined with metformin on DR. The levels of fasting blood glucose (FBG) and glycosylated hemoglobin (HbA1c) in blood were measured to evaluate the antihyperglycemic activity of DHK. Furthermore, levels of nitric oxide (NO), malondialdehyde (MDA) and activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) in serum were measured to study effects of DHK on oxidative stress in ZDF rats. In addition, body weight, lipidic indexes and insulin level were also assessed.

RESULTS

DHK combined with metformin significantly reversed the prolongation of latency times of flash electroretinogram (FERG) and oscillatory potentials (OPs) in diabetic rats. Furthermore, DHK alone or combined with metformin showed a remarkable suppression of retinal neovascularization and amelioration of retinal internal limiting membrane morphology. Moreover, DHK alone or plus metformin reduced FBG (P<0.05), HbA1c (P<0.01) and MDA (P<0.01) levels in diabetic rats. In addition, reductions in levels of triglycerides (TG) (P<0.01) and low density lipoprotein cholesterol (LDL-c) (P<0.01 and P<0.05, respectively) were also observed in diabetic rats treated with DHK alone or plus metformin.

CONCLUSION

DHK in combination with metformin had a preventive and therapeutic effect on DR in type-2 diabetic rats, and the possible mechanisms may be alleviating hyperglycemia, reducing oxidative stress and improving lipid metabolism.

Monounsaturated fatty acids-rich diets in hypercholesterolemic-growing rats

The effects of replacing dietary saturated fat by different monounsaturated fatty acid (ω-9MUFA) sources on serum lipids, body fat and bone in growing hypercholesterolemic rats were studied. Rats received one of the six different diets: AIN-93G (control, C); extra virgin olive oil (OO) + C; high-oleic sunflower oil (HOSO) + C or atherogenic diet (AT) for 8 weeks; the remaining two groups received AT for 3 weeks and then, the saturated fat was replaced by an oil mixture of soybean oil added with OO or HOSO for 5 weeks. Rats consuming MUFA-rich diets showed the highest body fat, hepatic index and epididymal, intestinal and perirenal fat, and triglycerides. T-chol and non-HDL-chol were increased in HOSO rats but decreased in OO rats. Bone mineral content and density were higher in both OO and HOSO groups than in AT rats. This study casts caution to the generalization of the benefits of MUFA for the treatment of hypercholesterolemia.

Pharmacokinetic and pharmacological effects of β-hydroxyphosphocarnitine in animal models

The purpose of this research was to describe the pharmacokinetic parameters of β-hydroxyphosphocarnitine (β-HPC; CAS No. 1220955-20-3) after a single oral dose in rats and rabbits as well as to assess the impact of 14 weeks of β-HPC (100 mg/kg) treatment on the serum metabolites and liver enzymes, body weight, and hepatic steatosis of lean and obese Zucker fa/fa rats. In the case of the rat and rabbit study, the β-HPC area under the curve, biological half-life, and clearance were 2,174.4 versus 3,128 μg ∙ h/ml, 23.7 versus 8.87 h, and 13.9 versus 151.1 ml/h in the rats versus the rabbits, respectively. The values for the time of maximal concentration were 0.58 versus 1.53 h, for the maximal concentration, they were 62.4 versus 221.4 μg/ml, and for the absorption rate constant 0.02 versus 2.40 h(-1), respectively. In the case of the Zucker fa/fa rat study, β-HPC administered orally once a day reduced insulin, triglyceride, and cholesterol levels in the liver and serum; it also reduced weight gain and decreased liver steatosis in obese rats after 14 weeks. β-HPC could therefore potentially be used in the treatment of metabolic syndrome.

The consumption of n-3 polyunsaturated fatty acids differentially modulates gene expression of peroxisome proliferator-activated receptor alpha and gamma and hypoxia-inducible factor 1 alpha in subcutaneous adipose tissue of obese adolescents

The aim of this study was to evaluate the effect of long-chain omega-3 polyunsaturated fatty acid (n-3 PUFA) supplementation on metabolic state and gene expression in subcutaneous adipose tissues of obese adolescents. Obese adolescents (n = 26, 10 girls and 16 boys) aged 12.4 ± 2.1 years were assigned to a 12-week regimen of n-3 PUFA intake. Five times per day, subjects received a food supplement consisting of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) (3 g per day, 944 mg EPA, and 2,088 mg DHA). Blood parameters were measured, and subcutaneous adipose tissue biopsies were analyzed to determine gene expression at baseline and after 12 weeks. Student's t test and the Wilcoxon signed-rank test were used to estimate differences in arithmetic means of pre- and post-dietary supplementation for various anthropometric, biochemical, clinical, and gene expression parameters. After 12 weeks, n-3 PUFA consumption was associated with decreased body mass index (29.7 ± 4.6 vs. 27.8 ± 4.4 kg/m(2); P < 0.001), waist circumference (93.2 ± 9.9 vs. 90.5 ± 10.0 cm; P < 0.003), hip circumference (102.9 ± 10.9 vs. 101.1 ± 10.9 cm; P < 0.014), and blood triglyceride levels (220.8 ± 27.4 vs. 99.7 ± 32.7 mg/dL; P < 0.001). Fatty acid supplementation/n3 PUFA supplementation was associated with a downregulated expression of the genes encoding PPARγ and PGC-1α (P < 0.001), and an upregulated expression of the genes encoding PPARα (P < 0.007) and SREBP1 (P < 0.021). The expressions of SOD2 (P < 0.04), CAT (P < 0.001), GPX3 (P < 0.032) and HIF-1α protein also decreased. Our study demonstrated that n-3 PUFA consumption and dietary restriction improved the anthropometric parameters and decreased the triglycerides levels of the adolescents, suggesting a reduction in hypoxia in subcutaneous adipose tissue.