Ketosis, Vascular Inflammation and Its Therapy in Type 1 Diabetic Patients

描述(由申请人提供)：本申请对美国国立卫生研究院的三项计划公告高度响应：PAR-06-457(糖尿病转化性研究)、PA-01-114(铬作为糖尿病辅助治疗)和PA-01-071(医学中的金属)。1型糖尿病与心血管疾病(CVD)发病率过高有关。血液中促炎症细胞因子白介素6和组织坏死因子α水平的升高是血管炎症的标志，血管炎症是心血管疾病的已知危险因素。除了高血糖外，1型糖尿病患者还经常出现酮症。我们的初步研究表明，在使用U937单核细胞的细胞培养模型中，酮体乙酰乙酸酯(AA)能产生超氧阴离子自由基并增加IL-6和TNF-α的分泌；在细胞培养模型中，高酮血症患者的血液中氧化应激以及IL-6和TNF-α水平高于正常酮血症的1型糖尿病患者；在细胞培养模型中，铬(Cr3)抑制由AA引起的TNF-α和IL-6的分泌。这项提议有两个假设。首先，酮病会增加1型糖尿病患者血液中血管炎症标志物的水平。第二，补充CR3可以预防/降低1型糖尿病患者血液中血管炎症标志物的水平。这些假设将在1型糖尿病患者身上进行体内验证，并在体外使用从受试者血液和购买的人主动脉内皮细胞(HAEC)中分离的单核细胞进行研究。在体内，将检查高酮血症和补充安慰剂(P)或CR3对血管炎症标志物水平的影响。在体外，将从P或CR3补充患者或HAEC分离的单核细胞与酮一起培养，以检测其对血管炎症标志物以及单核细胞和HAEC中与细胞因子产生和黏附分子相关的基因表达的直接影响。这是一项新的研究，因为先前没有研究检验酮症或CR3对1型糖尿病患者血管炎症的影响。为了实现这些目标，将从1型糖尿病儿童身上采集血液。患者(n=141，年龄12-18岁)将补充P或200或500克CR3-烟酸酯/天，为期3个月。将使用最先进的方法，如多重聚合酶链式反应。数据将进行统计分析。糖尿病的发病率已经成为流行病，并且仍然是一个主要的公共卫生问题。长期目标是了解酮症在心血管疾病中的作用，并发现一种相对低成本的膳食补充剂，可用作预防1型糖尿病心血管疾病的辅助治疗。

DESCRIPTION (provided by applicant): This application is highly responsive to three program announcements of the NIH: PAR-06-457 (Translational Research in Diabetes), PA-01-114 (Chromium as Adjuvant Therapy in Diabetes), and PA-01- 071 (Metals in Medicine). Type-1 diabetes is associated with excessive incidence of cardiovascular disease (CVD). Elevated blood levels of the pro-inflammatory cytokines interleukin (IL)-6 and tissue necrosis factor (TNF)-a are markers of vascular inflammation, a known risk factor for CVD. In addition to hyperglycemia, type 1 diabetic patients frequently experience ketosis. Our preliminary studies have demonstrated that the ketone body acetoacetate (AA) can generate superoxide radicals and increase secretion of IL-6 and TNF-a in a cell culture model using U937 monocytes; that oxidative stress and levels of IL-6 and TNF-a are higher in the blood of hyperketonemic compared with normoketonemic type 1 diabetic patients; and that chromium (Cr3+) inhibits the secretion of TNF-a and IL-6 caused by AA in a cell culture model. This proposal has two hypotheses. The first is that ketosis increases blood levels of markers of vascular inflammation in type 1 diabetes. The second is that Cr3+ supplementation can prevent/lower blood levels of vascular inflammation markers in type 1 diabetes. These hypotheses will be tested both in vivo in type 1 diabetic patients as well as in vitro in studies using monocytes isolated from subject's blood and purchased human aortic endothelial cells (HAEC). In vivo, the effects of hyperketonemia, and supplementation with either placebo (P) or Cr3+ on the levels of markers of vascular inflammation will be examined. In vitro, monocytes isolated from P or Cr3+ supplemented patients or HAEC will be cultured with ketones to examine their direct effect on markers of vascular inflammation and gene expression related to cytokine production and adhesion molecules in monocytes and HAEC. This is a novel study because no prior study has examined the effect of ketosis or Cr3+ on vascular inflammation in type 1 diabetes. To accomplish these objectives, blood will be collected from type 1 diabetic children. Patients (n=141, ages 12- 18 yrs) will be supplemented with either P or 200 or 500¿g Cr3+-niacinate/day for 3 months. State of the art methodology, such as multiplex PCR, will be used. Data will be analyzed statistically. Diabetes incidence has become epidemic and remains a major public health issue. The long-term goal is to understand the role of ketosis in CVD and to discover a relatively low-cost dietary supplement that could be used as an adjuvant therapy for CVD prevention in type 1 diabetes.