背景:研究表明,长期使用大麻与血压下降有关。我们先前的研究证明,激活大脑中的大麻素2型(CB2)受体可以有效降低自发性高血压大鼠的血压;然而,确切的机制尚未明确。这项研究的目的是证明激活小胶质细胞CB2受体可以有效降低TNF-α的水平。IL-1β,和IL-6在室旁核(PVN)通过抑制有氧糖酵解,从而缓解高血压。
方法:对BV2细胞和C57小鼠施用血管紧张素II(AngII)以诱导高血压和促炎细胞因子的释放。CB2受体的mRNA和蛋白表达,TNF-α,IL-1β,使用RT-qPCR和Western印迹检测IL-6以及PFK和LDHa酶。海马XF能量代谢分析仪用于测量BV2细胞中的氧化磷酸化和有氧糖酵解代谢途径。注射选择性CB2受体激动剂JWH133的长期效果,腹膜内对血压进行测定。ELISA用于测量去甲肾上腺素和乳酸水平,而免疫荧光标记用于定位CB2受体和c-Fos。通过将pAAV-F4/80-GFP-mir30shRNA(AAV2-r-CB2shRNA)注射到侧脑室,小胶质细胞中的CB2受体被特异性敲除。
结果:激动剂JWH133对CB2受体的激活抑制了TNF-α,IL-1β,和IL-6通过抑制参与糖酵解的PFK和LDHa酶,以及乳酸的积累,伴随着AngII处理的BV2细胞中glyPER水平的降低(有氧糖酵解的标志)。在AngII治疗的小鼠中,在小胶质细胞上施用JWH133特异性激活的CB2受体,导致PFK的表达水平降低,LDHa,TNF-α,IL-1β,和IL-6,随后导致PVN神经元内c-Fos蛋白表达减少以及血浆去甲肾上腺素水平降低,最终有助于降低血压。
结论:结果表明,激活小胶质细胞CB2受体可减少神经炎症,从而缓解高血压;其潜在机制与抑制小胶质细胞的有氧糖酵解有关。
BACKGROUND: Studies have shown that the chronic use of cannabis is associated with a decrease in blood pressure. Our previous studies prove that activating the cannabinoid type 2 (CB2) receptor in the brain can effectively reduce blood pressure in spontaneously hypertensive rats; however, the exact mechanism has not been clarified. The objective of this study is to demonstrate that activation of microglial CB2 receptors can effectively reduce the levels of TNF-α, IL-1β, and IL-6 in the paraventricular nucleus (PVN) through inhibiting aerobic glycolysis, thereby relieving hypertension.
METHODS: AngiotensinII (AngII) was administered to BV2 cells and C57 mice to induce hypertension and the release of proinflammatory cytokines. The mRNA and protein expression of the CB2 receptor, TNF-α, IL-1β, IL-6, and the PFK and LDHa enzymes were detected using RT-qPCR and Western blotting. The Seahorse XF Energy Metabolism Analyzer was used to measure the oxidative phosphorylation and aerobic glycolysis metabolic pathways in BV2 cells. The long-term effects of injecting JWH133, a selective CB2 receptor agonist, intraperitoneally on blood pressure were ascertained. ELISA was used to measure norepinephrine and lactic acid levels while immunofluorescence labeling was used to locate the CB2 receptor and c-Fos. By injecting pAAV-F4/80-GFP-mir30shRNA (AAV2-r-CB2shRNA) into the lateral cerebral ventricle, the CB2 receptor in microglia was specifically knocked down.
RESULTS: Activation of CB2 receptors by the agonist JWH133 suppressed TNF-α, IL-1β, and IL-6 by inhibiting PFK and LDHa enzymes involved in glycolysis, as well as lactic acid accumulation, along with a reduction in glycoPER levels (marks of aerobic glycolysis) in AngII-treated BV2 cells. In AngII-treated mice, the administration of JWH133 specifically activated CB2 receptors on microglia, resulting in decreased expression levels of PFK, LDHa, TNF-α, IL-1β, and IL-6, subsequently leading to a decrease in c-Fos protein expression within PVN neurons as well as reduced norepinephrine levels in plasma, ultimately contributing to blood pressure reduction.
CONCLUSIONS: The results suggest that activation of the microglia CB2 receptor decreases the neuroinflammation to relieve hypertension; the underlying mechanism is related to inhibiting aerobic glycolysis of microglia.