Contribution of thrombin-reactive brain pericytes to blood-brain barrier dysfunction in an in vivo mouse model of obesity-associated diabetes and an in vitro rat model.
Contribution of thrombin-reactive brain pericytes to blood-brain barrier dysfunction in an in vivo mouse model of obesity-associated diabetes and an in vitro rat model.
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DOI：
10.1371/journal.pone.0177447
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发表时间：
2017
期刊：
影响因子：
3.7
通讯作者：
Yamauchi A
中科院分区：
文献类型：
--
作者：
Machida T;Takata F;Matsumoto J;Miyamura T;Hirata R;Kimura I;Kataoka Y;Dohgu S;Yamauchi A
糖尿病并发症的特征是位于微血管内皮细胞周围的周细胞功能障碍。随着糖尿病的进展，血脑屏障（BBB）表现出渗透性过高。因此，BBB 的大脑周细胞可能与中枢神经系统 (CNS) 的糖尿病并发症有关。我们假设大脑周细胞对糖尿病患者脑凝血酶水平升高做出反应，导致血脑屏障功能障碍和糖尿病中枢神经系统并发症。小鼠被喂食高脂肪饮食 (HFD) 2 周或 8 周以诱导肥胖。测量了静脉注射荧光素钠和 125I-凝血酶穿过 BBB 的转运情况。我们使用共培养的大鼠脑内皮细胞和周细胞的 BBB 模型评估了在凝血酶处理的脑周细胞存在下脑内皮通透性和紧密连接蛋白的表达。喂食 HFD 8 周的小鼠表现出体重增加增加和糖耐量受损。与此同时，荧光素钠的脑流入率显着高于正常饮食的小鼠。 HFD 喂养抑制了 6 周喂养期间脑凝血酶水平的下降。在喂食 HFD 的小鼠中，血浆凝血酶水平显着升高，最高可达 22%。正常小鼠静脉注射后，125I-凝血酶被转运穿过血脑屏障。注射，通过共同注射未标记的凝血酶进一步增强摄取。凝血酶处理的脑周细胞增加了脑内皮通透性，并导致 occlusionns-1 (ZO-1) 和 occludin 的表达减少以及 ZO-1 的形态紊乱。凝血酶还增加脑周细胞中白细胞介素 1β 和 6 以及肿瘤坏死因子 α 的 mRNA 表达。凝血酶可以从循环血液中通过血脑屏障转运，在大脑中维持恒定水平，从而刺激周细胞诱导血脑屏障功能障碍。因此，大脑周细胞-凝血酶相互作用可能在导致肥胖相关糖尿病的血脑屏障功能障碍中发挥关键作用，并代表其中枢神经系统并发症的治疗靶点。
Diabetic complications are characterized by the dysfunction of pericytes located around microvascular endothelial cells. The blood–brain barrier (BBB) exhibits hyperpermeability with progression of diabetes. Therefore, brain pericytes at the BBB may be involved in diabetic complications of the central nervous system (CNS). We hypothesized that brain pericytes respond to increased brain thrombin levels in diabetes, leading to BBB dysfunction and diabetic CNS complications. Mice were fed a high-fat diet (HFD) for 2 or 8 weeks to induce obesity. Transport of i.v.-administered sodium fluorescein and 125I-thrombin across the BBB were measured. We evaluated brain endothelial permeability and expression of tight junction proteins in the presence of thrombin–treated brain pericytes using a BBB model of co-cultured rat brain endothelial cells and pericytes. Mice fed a HFD for 8 weeks showed both increased weight gain and impaired glucose tolerance. In parallel, the brain influx rate of sodium fluorescein was significantly greater than that in mice fed a normal diet. HFD feeding inhibited the decline in brain thrombin levels occurring during 6 weeks of feeding. In the HFD fed mice, plasma thrombin levels were significantly increased, by up to 22%. 125I-thrombin was transported across the BBB in normal mice after i.v. injection, with uptake further enhanced by co-injection of unlabeled thrombin. Thrombin-treated brain pericytes increased brain endothelial permeability and caused decreased expression of zona occludens-1 (ZO-1) and occludin and morphological disorganization of ZO-1. Thrombin also increased mRNA expression of interleukin-1β and 6 and tumor necrosis factor-α in brain pericytes. Thrombin can be transported from circulating blood through the BBB, maintaining constant levels in the brain, where it can stimulate pericytes to induce BBB dysfunction. Thus, the brain pericyte–thrombin interaction may play a key role in causing BBB dysfunction in obesity-associated diabetes and represent a therapeutic target for its CNS complications.