Effect of dietary Schizochytrium microalga oil on selected markers of low‐grade inflammation in rats

The objective of the present study was to evaluate a potential of Schizochytrium microalga oil to alleviate possible negative effects of high‐fat‐high‐energy diets. Forty adult male rats (Wistar Albino) were fed 7 weeks the diet containing beef tallow + evaporated sweetened milk (diet T) intended to cause mild obesity and low‐grade systemic inflammation. Consequently, the animals were divided into four groups by 10 animals each and fed either the T‐diet (control) or the diet containing 6% of safflower oil (S), 6% of fish oil (F) and 6% of Schizochytrium microalga oil (A), respectively, for another 7 weeks. The A‐diet decreased (p < 0.05) live weight to 86% and glycaemia to 85% of control, respectively; an effect of the S‐ and F‐diet on these markers was insignificant (p > 0.05). In comparison with control, higher (p < 0.05) deposition of eicosapentaenoic acid (EPA) + docosahexaenoic acid (DHA) in the epididymal adipose tissue (EAT) of the A‐rats correlated with increased (p < 0.05) plasma adiponectin concentration, but it was without the effect (p > 0.05) on cellular adiponectin content in the EAT. Higher (p < 0.05) EPA+DHA deposition in the liver of the A‐rats correlated with higher expression (149% of control; p < 0.05) of the gene coding for peroxisome proliferator‐activated receptor gamma, and with lower expression (82% and 66%; p < 0.05) of the genes coding for adiponectin receptors AdipoR1 and AdipoR2; no relationship to the expression of receptor GPR120 was found. The A‐diet did not affect amount of the nuclear fraction of the nuclear factor kappa B in the liver, but increased plasma level of anti‐inflammatory cytokine TGF‐β1 (p < 0.05). The presented data agree with results of other in vivo rodent and human studies, but not with literature data regarding in vitro experiments: it can be concluded that the effects of dietary oils on inflammatory markers need further investigation.     

Serum adipokine concentrations in dogs with diabetes mellitus: a pilot study

This study was conducted to determine whether serum adipokine concentrations differed between healthy dogs and dogs with diabetes mellitus (DM). To accomplish this, 19 dogs with newly diagnosed DM were compared to 20 otherwise healthy dogs. The serum concentrations of visfatin, leptin, IL-1β, IL-6, IL-18, and TNF-α were significantly higher in diabetic dogs than in healthy dogs, whereas the serum adiponectin concentrations were lower in diabetic dogs. However, there were no significant differences in the IL-10 and resistin levels between groups. The serum leptin concentrations in diabetic dogs with and without concurrent disorders differed significantly. Treatment with insulin induced a significant decrease in IL-6 in diabetic dogs without concurrent disorders. These results show that the clinical diabetic state of dogs could modulate the circulating visfatin and adiponectin concentrations directly, while upregulation of leptin was probably a result of concurrent disorders rather than an effect of persistent hyperglycemia as a result of DM.     

Adiponectin‐impaired adipocyte differentiation negatively regulates fat deposition in chicken

Adiponectin is a protein hormone secreted exclusively by adipocytes that plays an important role in the modulation of glucose and lipid metabolism. To investigate the effect of adiponectin on lipid metabolism in chicken, rosiglitazone (agonist of adiponectin) and dexamethasone (inhibitor of adiponectin) were used to treat 23‐day‐old broilers in vivo. To verify the functionality of adiponectin on fat deposition, chicken pre‐adipocytes were cultured in the medium containing 10 μg/ml adiponectin. Serum adiponectin and lipids and fat distribution were analysed. Oil Red O staining was used to determine lipid deposition in adipocytes. The expression levels of adiponectin, adiponectin receptors (AdipoR) and lipid metabolism–related genes in different tissues and pre‐adipocytes were measured using real‐time PCR, and the abundance of lipid metabolism–related proteins was measured by Western blot. Rosiglitazone increased serum adiponectin concentration and the expression levels of adiponectin and adiponectin receptor 1 (AdipoR1) in tissues and significantly decreased levels of serum lipids and fat deposition. Rosiglitazone significantly increased the expression levels of adipose triglyceride lipase (ATGL) and AdipoR1 and decreased the expression levels of fatty acid synthase (FAS). Dexamethasone had the converse effects compared with rosiglitazone. Oil red O staining results showed a marked decrease in fat deposition in cells treated with adiponectin. In adipocytes, adiponectin could decrease the expression levels of CCAAT/enhancer‐binding protein α (C/EBPα) and FAS and increased the expression levels of ATGL and AdipoR1. These results indicate that adiponectin has a remarkable effect on impairment of adipocyte differentiation, which contributes to the negative regulation of fat deposition in chicken.     

藏羊脂联素基因多态性及其与产肉性能的相关性分析

利用高分辨率熔解曲线技术对176头2周岁的甘肃藏羊（欧拉型、甘加型、乔科型）脂联素基因SNPs位点进行检测,运用GLM模型将检测到的SNPs位点与部分胴体及肉质性状的相关性进行了分析.结果表明：在脂联素第2外显子发现＋67G＞C突变使编码氨基酸由谷氨酸突变为谷氨酰胺;GG、GC基因型个体的宰前活重、胴体重均显著高于CC型（P＜0.05）.说明脂联素基因该位点可能是影响藏羊胴体及肉质性状的主效QTL或与之紧密连锁,可作为藏羊高档羊肉生产的候选分子标记.     

Regulation of hepatic peroxisome proliferator‐activated receptor α expression but not adiponectin by dietary protein in finishing pigs

Soy protein regulates adiponectin and peroxisome proliferator‐activated receptor α (PPARα) in some species, but the effect of dietary soy protein on adiponectin and PPARα in the pig has not been studied. Therefore, the objective of this study was to determine whether soya bean meal reduction or replacement influences serum adiponectin, adiponectin mRNA, serum metabolites and the expression of PPARα and other genes involved in lipid deposition. Thirty‐three pigs (11 pigs per treatment) were subjected to one of three dietary treatments: (i) reduced crude protein (CP) diet containing soya bean meal (RCP‐Soy), (ii) high CP diet containing soya bean meal (HCP‐Soy) or (iii) high CP diet with corn gluten meal replacing soya bean meal (HCP‐CGM) for 35 days. Dietary treatment had no effect on overall growth performance, feed intake or measures of body composition. There was no effect of dietary treatment on serum adiponectin or leptin. Dietary treatment did not affect the abundance of the mRNAs for adiponectin, PPARα, PPARγ2, lipoprotein lipase or fatty acid synthase in adipose tissue. The mRNA expression of PPARα, PPARγ2, lipoprotein lipase or fatty acid synthetase in loin muscle was not affected by dietary treatment. In liver tissue, the relative abundance of PPARα mRNA was greater (p < 0.05) in pigs fed the HCP‐Soy diets when compared to pigs fed RCP‐Soy or HCP‐CGM diets. Hepatic mRNA expression of acyl‐CoA oxidase or fatty acid synthase was not affected by dietary treatment. Western blot analysis indicated that hepatic PPARα protein levels were decreased (p < 0.05) in pigs fed the RCP‐Soy diets when compared to pigs fed the HCP‐Soy diets. These data suggest that increasing the soy protein content of swine diets increases hepatic expression of PPARα without associated changes in body composition.     

Expression and localization of adiponectin and its receptors in ovarian follicles during different stages of development and the modulatory effect of adiponectin on steroid production in water buffalo

Adiponectin is an adipocyte‐derived hormone regulating energy metabolism, insulin sensitivity and recently found to regulate reproduction. The current study was carried out to investigate gene and protein expression, immunolocalization of adiponectin and its receptors AdipoR1 and AdipoR2 in ovarian follicles of different developmental stages in water buffalo (Bubalus bubalis) and to investigate the effect of adiponectin on steroid production in cultured bubaline granulosa cells. qPCR, western blotting and immunohistochemistry were applied to demonstrate mRNA expression, protein expression and immunolocalization, respectively. The results indicate that adiponectin, AdipoR1 and AdipoR2 were present in granulosa cells (GC) and theca interna (TI) of ovarian follicles and the expression of adiponectin, AdipoR1, AdipoR2 in GC and AdipoR1 and AdipoR2 in TI increased with increase in follicle size (p < .05). Expression of adiponectin was high in small and medium size follicles in TI. The adiponectin and its receptors were immunolocalized in the cytoplasm of GC and TI cells. Further, in the in‐vitro study, GCs were cultured and treated with recombinant adiponectin each at 0, 1 and 10 µg/ml alone or with follicle stimulating hormone (FSH) at 30 ng/ml) or Insulin‐like growth factor I (IGF‐I) at 10 ng/ml for 48 hr after obtaining 75%–80%s confluency. Adiponectin at 10 µg/ml increased IGF‐I‐induced estradiol (E₂) and progesterone (P₄) secretion and FSH‐induced E₂ secretion from GC and also increased the abundance of factors involved in E₂ and P₄ production (cytochrome P45019A1 [CYP19A1] and 3‐beta‐hydroxysteroid dehydrogenase [3β‐HSD]). In conclusion, this study provides novel evidence for the presence of adiponectin and its receptors in ovarian follicles and modulatory role of adiponectin on steroid production in buffalo.     

牛脂联素cDNA全基因序列的克隆

[目的]体外克隆牛脂联素基因的编码全序列。[方法]以成牛尾部脂肪的总RNA为模板,通过RT-PCR扩增获得牛脂联素基因cDNA的全序列,将其克隆到原核表达载体PMD18-T中,筛选出阳性克隆,提取重组质粒,通过限制性内切酶酶切鉴定和重组质粒PCR鉴定后对其进行测序。[结果]从牛尾部脂肪组织总RNA中扩增得到671bp的目的条带,该cDNA序列与GenBank中牛脂联素基因序列同源性为100％,其氨基酸同源性也达到100％,确定为目的基因。[结论]该研究为进一步研究牛脂联素基因的功能和研究牛脂联素基因的表达与育肥牛的脂肪代谢的关系提供了试验基础。     

脂联素及其受体与GnRH和GnIH在皖南花猪下丘脑中的发育性表达及相关性研究

【目的】探讨不同发育时期皖南花猪下丘脑脂联素受体及生殖相关激素表达的发育性变化及其相关性。【方法】选择0,30,45,90,180日龄皖南花猪公、母猪各5头,采集其血清和下丘脑组织,采用ELISA法检测各日龄猪血清中脂联素(Adp)质量浓度和促性腺激素释放激素(GnRH)、促性腺激素抑制激素(GnIH)的活性,用实时荧光定量PCR方法检测猪下丘脑中Adp、脂联素受体1(AdpR1)、2(AdpR2)及GnRH、GnIH mRNA表达量的发育性变化和性别差异。【结果】不同日龄皖南花猪血清Adp与GnRH、GnIH水平均有极显著的发育性变化,其中30日龄猪的脂联素极显著低于其他日龄(P<0.01),而GnRH和GnIH水平极显著高于其他日龄(P<0.01);下丘脑Adp mRNA表达量很低,AdpR1mRNA、AdpR2mRNA在不同发育阶段的表达量相对较为稳定(P>0.05),AdpR1mRNA表达量在各个日龄均显著高于AdpR2mRNA。下丘脑GnRH、GnIH mRNA的发育性变化总体呈下降趋势,刚出生母猪的下丘脑GnRH mRNA表达量显著高于其他日龄(P<0.05)。不同性别比较发现,公猪AdpR1mRNA在0日龄、AdpR2和GnRH mRNA在30日龄显著高于母猪(P<0.05)。血清Adp与GnRH水平呈显著负相关(P<0.05),母猪Adp与GnRH呈显著负相关(P<0.05),母猪下丘脑组织中AdpR1、AdpR2表达量与GnRH mRNA呈负相关。公、母猪的GnRH与GnIH含量均极显著相关(P<0.01)。【结论】在皖南花猪发育过程中,脂联素对下丘脑的调节可能主要通过内分泌方式发挥作用,并由AdpR1介导抑制GnRH的分泌,且抑制作用主要表现在母猪中。     

武定鸡脂联素基因多态性分析

[目的]对武定鸡脂联素基因（NC_006096）第1外显子上的c.A99G突变位点进行多态性分析。[方法]翅静脉采集67只武定鸡全血,提取基因组DNA,采用PCR-RFLP法分析Hsp92Ⅱ限制性内切酶对PCR产物进行单酶切的结果。[结果]在c.A99G同义突变位点上存在AA、AB和BB 3种基因型,其中A基因频率为0.686 6,B基因频率为0.313 4;PIC=0.337 8,表明该位点为中度多态位点;χ²适合性检验表明,脂联素基因c.A99G位点处于平衡状态。[结论]采用PCR-RFLP法可有效检测武定鸡脂联素基因c.A99G突变,该位点有3种基因型,等位基因呈中度遗传多态水平且处于平衡状态。     

Investigation of the Effects of a Dietary Supplement on Insulin and Adipokine Concentrations in Equine Metabolic Syndrome/Insulin Dysregulation

High insulin concentrations are a common clinical feature of equine metabolic syndrome (EMS) and insulin dysregulation. Hyperinsulinemia can induce laminitis, so reduction of insulin concentrations in response to an oral challenge should decrease risk. In human studies, diets containing a polyphenol (resveratrol) led to improvements in insulin sensitivity. In rodents, the addition of leucine to a resveratrol supplement caused a decrease in the amount of resveratrol needed to achieve a clinical effect. We hypothesize a supplementation with a low dose of a synergistic polyphenol and amino acid blend including leucine (SPB+L) would improve metabolic health in EMS/insulin dysregulated horses. Fifteen EMS/ID horses received a high or low dose of SPB+ L daily for 6 weeks. Insulin during an oral sugar test (OST), body condition score, weight, baseline high-molecular-weight (HMW) adiponectin, triglycerides, nonesterified fatty acids, and tumor necrosis factor alpha were assessed before supplementation (PRE) and after supplementation (POST) via paired Student’s t-tests and a repeated-measures mixed-model analysis of variance (significant at P < .05). There were no differences between doses. Horses in the POST group weighed significantly less, had significantly higher baseline HMW adiponectin concentrations, and had significantly lower insulin concentrations at 60- and 75-minute time points (P < .05). Insulin concentrations of the horsesin the POST group, but not in the PRE group, were lower and similar to results from the study conducted three years before the present study (PRIOR) for 0- and 60-minute time points (P < .002). An increased HMW adiponectin level supports increasing insulin sensitivity after supplementation. These results suggest that SPB + L supplementation at either dose leads to improvements in the clinical manifestations of EMS/insulin dysregulation, potentially reducing laminitis risk.