ω-3多不饱和脂肪酸对慢性移植物抗宿主病狼疮小鼠的免疫调控作用

目的探讨ω-3多不饱和脂肪酸(ω-3 poly unsaturated fatty acids,ω-3 PUFAs)对慢性移植物抗宿主病(chronic graft versus host disease,cGVH)狼疮模型小鼠的免疫调节功能影响。方法单次腹腔注射bm12小鼠淋巴细胞建立cGVH小鼠模型,造模当天分别给予90%ω-3 PUFAs和97%EPA灌胃治疗,持续14 d。通过流式细胞术检测小鼠脾脏淋巴细胞中各免疫指标,ELISA检测小鼠血清中总IgG水平。结果与正常对照组相比,cGVH组明显下调Treg亚群,明显上调T_FH细胞、生发中心B细胞和浆细胞亚群;与模型对照组相比,90%ω-3和97%EPA均明显上调Treg亚群,并明显下调T_FH细胞、生发中心B细胞和浆细胞亚群;且97%EPA组小鼠血清中总IgG水平明显下降。结论在cGVH狼疮小鼠模型中,ω-3 PUFAs通过增加Treg细胞,减少T_FH细胞、生发中心B细胞和浆细胞,抑制IgG的分泌,从而发挥免疫抑制作用,且其免疫抑制作用可能与ω-3 PUFAs含量相关。     

ω-3多不饱和脂肪酸联合营养支持治疗在肝切除术后应用的临床研究

目的 通过比较不同营养支持方案的作用,评价ω-3多不饱和脂肪酸联合营养支持治疗在肝切除术后应用的临床效果。方法 采用回顾性对照研究的方法.选择2009年1月-2011年1月南京大学医学院附属鼓楼医院82例行肝切除术患者,依照围手术期不同的营养支持方案分为全肠外营养组（23例,简称肠外组）、联合肠内营养组（30例,简称肠内组）和ω-3不饱和脂肪酸组（29例,简称ω-3 PUFAs组）。肠外组术后给予全肠外营养支持;肠内组在静脉营养支持基础上术后早期口服肠内营养;ω-3 PUFAs组在肠内组基础上,术后加用ω-3多不饱和脂肪酸。通过比较3组患者术后恢复情况、并发症发病率、肝功能等临床指标综合评估不同营养支持方案的疗效。结果 （1）3组患者术后均无胆漏、胆道出血等严重并发症,轻微并发症包括腹腔积液、胸腔积液,3组间差异无统计学意义;（2）与肠外组比较,肠内组、ω-3 PUFAs组术后排便时间、术后住院天数较短,差异有统计学意义（P =0.001,=4.624;P =0.001,t =5.019）;肠内组、ω-3PUFAs组间差异无统计学意义（P＞0.05）;（3）对于大范围（≥4个肝段）肝切除患者,与肠内组相比,ω-3PUFAs组术后第3、5天ALT值较低,差异有统计学意义（P=0.024,t=2.432;P=0.042,=2.144）;（4）对于有肝硬化的患者,与肠内组相比,ω-3 PUFAs组术后第3、5天胆红素值较低,差异有统计学意义（P=0.032,t=2.202;P=0.035,t =2.183）。结论 肝切除术后早期给予肠内营养并联合肠外营养支持,可加速患者康复;对于有肝硬化背景及大范围肝切除的患者,ω-3 PUFAs联合营养支持治疗对肝功能的保护作用尤为明显。     

Fish-oil emulsion (omega-3 polyunsaturated fatty acids) attenuates acute lung injury induced by intestinal ischemia–reperfusion through Adenosine 5′-monophosphate-activated protein kinase–sirtuin1 pathway

Background

Activated macrophage infiltration into the lungs is paramount in the pathogenesis of acute lung injury (ALI) induced by intestinal ischemia–reperfusion (I/R). Omega-3 polyunsaturated fatty acid (ω-3 PUFA) is a potent activator of the Adenosine 5′-monophosphate-activated protein kinase–sirtuin1 (AMPK/SIRT1) pathway against macrophage inflammation. We aimed to evaluate whether ω-3 PUFAs may protect against ALI induced by intestinal I/R via the AMPK/SIRT1 pathway.

Methods

Ischemia in male Wistar rats was induced by superior mesenteric artery occlusion for 60 min and reperfusion for 240 min. One milliliter per day of fish-oil emulsion (FO emulsion, containing major ingredients as ω-3 PUFAs) or normal saline (control) was administered by intraperitoneal injection for three consecutive days to each animal. All animals were sacrificed at the end of reperfusion. Blood and tissue samples were collected for analysis.

Results

Intestinal I/R caused intestinal and lung injury, evidenced by severe lung tissue edema and macrophage infiltration. Pretreatment with FO emulsion improved the integrity of microscopic structures in the intestine and lungs. Intestinal I/R induced the expression of macrophage-derived mediators (macrophage migration inhibitory factor and macrophage chemoattractant protein-1), inflammatory factors (nuclear factor κB, tumor necrosis factor α, interleukin 6, and interleukin 1β), and proapoptosis factor p66shc. There was a decrease in the expression of AMPK, SIRT1, and claudin 5. FO emulsion significantly inhibited macrophage infiltration into the lungs, inflammatory factor expression, and p66shc phosphorylation. Importantly, FO emulsion restored AMPK, SIRT1, and claudin 5 in the lungs.

Conclusions

Pretreatment with ω-3 PUFAs effectively protects intestinal and lung injury induced by intestinal I/R, reduces macrophage infiltration, suppresses inflammation, inhibits lung apoptosis, and improves the lung endothelial barrier after intestinal I/R in a manner dependent on AMPK/SIRT1. Thus, there is a potential for developing AMPK/SIRT1 as a novel target for patients with intestinal I/R–induced ALI.     

The protective role of endogenous n-3 polyunsaturated fatty acids in Tau Alzheimer’s disease mouse model

Objectives: The role of n-3 polyunsaturated fatty acid (PUFA) as the main docosahexaenoic acid (DHA) in Alzheimer’s disease (AD) remains controversial. Our study aimed to provide detailed information about the role of endogenous n-3 PUFAs in AD.

Methods: Here, we generated a fat-1/tau transgenic mouse AD model by crossing female tau mice with male fat-1 mice to exclude confounding variables associated with the benefit of a DHA diet in these AD mice models. PUFAs presented in these AD models were detected by gas chromatography, and the role of endogenous n-3 PUFAs was assessed by lifespan survival assay, behavioral, pathologic, and molecular biology testing as well as imaging of cerebral vasculature.

Results: Endogenous n-3 PUFAs were shown to improve the memory and learning ability of AD mice. One possible reason for this improvement is the reduced formation of neurotrophic factors (NFTs) and Aβ amyloid plaques which usually damage hippocampal neurons. Additionally, endogenous n-3 PUFAs were demonstrated to protect cerebral vascular of AD mice, thereby increasing brain metabolism. Besides, endogenous n-3 PUFAs were observed to extend of the overall survival of tau mouse models.

Conclusion: Endogenous n-3 PUFAs delayed the onset of Alzheimer's disease caused by tau protein dysfunction, alleviating related symptoms and significantly prolonging survival in vivo.     

Supplementation of omega 3 fatty acids improves oxidative stress in activated BV2 microglial cell line

Abstract

Many reports have shown promising beneficial effects of long-chain polyunsaturated fatty acids (L-PUFAs) of the omega 3 series in several brain diseases. In the present study, we tested the hypothesis that omega 3 fatty acids supplement reduced pro-inflammatory functions in vitro and in vivo. We demonstrated that a supplement rich in PUFAs (SRP) increased cell viability in a dose-dependent manner suggesting its protective role against lipopolysaccharide (LPS)-induced cell death in BV2 microglial cell line. In the same cultures, the supplement rich in PUFAs reduced the reactive oxygen species (ROS) and nitric oxide (NO) production. A most prominent target for ROS management is the family of peroxisome proliferator-activated receptors (PPARs). The co-treatment with SRP and LPS increased significantly the nuclear immunoreactivity of PPAR-γwhen compared the LPS treatment alone. Moreover, the chronic administration of the SRP in rats, increased the immunoreactivity of the PPAR-γ1 protein confirming its potential neuroprotective effect.     

Fish oil prevents colon cancer by modulation of structure and function of mitochondria

Cancer cells are more susceptible to metabolic perturbations due to impaired electron transport chain (ETC) that promote uncontrolled proliferation. Mitochondria play a pivotal role in bioenergetics and apoptosis, hence are considered as a promising target in tumor cell eradication. Therefore, the present study is designed to elucidate chemopreventive action of fish oil (FO) in combination with corn oil (CO) on mitochondria in colorectal cancer (CRC). Male Wistar rats were divided into groups depending on dietary regimen—Control group, FO + CO(1:1) and FO + CO(2.5:1). These groups were further subdivided depending on whether these received a weekly intraperitoneal injection of ethylenediamine tetra-acetic acid (EDTA) or N,N-dimethylhydrazine dihydrochloride (DMH) for a period of 4 weeks. The animals sacrificed 48 h and 16 weeks after EDTA/DMH treatment constituted initiation and post-initiation phase respectively. The structural and functional alterations in mitochondria were evaluated using transmission electron microscopy (TEM) and by assaying electron transport chain (ETC) enzymes. Mitochondrial lipid composition and cholesterol levels were also assessed. DMH treatment led to mitochondrial degeneration, disrupted cristae and a significant decrease in ETC complexes suggestive of metabolic reprogramming. Moreover, an increase in cholesterol and cardiolipin (CL) levels in post-initiation phase led to evasion of apoptosis. FO in both the ratios resulted in stabilization and increase in number of mitochondria, however, FO + CO(2.5:1) + DMH group also exhibited mitophagy and crystolysis alongwith altered dynamics in ETC which facilitated apoptosis. It also decreased cholesterol and CL levels to increase apoptosis. Fish oil targets mitochondria in a dose dependent manner that augments apoptosis and hence attenuates carcinogenesis.     

ω-3PUFAs对LPS诱导急性肺损伤大鼠前炎症因子TNF-α、IL-1β、IL-6的影响

目的 分析ω-3PUFAs对脂多糖诱导的急性肺损伤大鼠(acute lung injury, ALI)TNF-α、IL-1β和IL-6分泌的影响。方法 60只Sprague-Dawley幼年大鼠按随机数字分为Control组(生理盐水+生理盐水)、LPS组(生理盐水+脂多糖)和Omega(10%脂肪乳尤文+脂多糖)组。各组分别采用生理盐水或尤文脂肪乳剂处理7 d;并均在取标本前8 h时于气管内滴入生理盐水或脂多糖, 建立ALI大鼠模型;观察各组大鼠肺组织的病理改变, 测定肺泡灌洗液TNF-α、IL-1β、IL-6的表达。结果 1)ALI模型组大鼠肺组织病理切片均可见明显炎症细胞浸润和出血;2)ALI模型组肺系数、病理评分均高于Control组(P均＜0.05);3)BALF中Omega组TNF-α、IL-1β和IL-6蛋白水平低于LPS组, 差异具有统计学意义(P均＜0.05)。结论 ω-3PUFAs能够通过降低TNF-α、IL-1β和IL-6的分泌而减轻ALI大鼠炎症反应, 减轻肺部损伤。