Metformin inhibits intracranial aneurysm formation and progression by regulating vascular smooth muscle cell phenotype switching via the AMPK/ACC pathway.
二甲双胍通过 AMPK/ACC 通路调节血管平滑肌细胞表型转换抑制颅内动脉瘤形成和进展。
- 作者列表："Li S","Shi Y","Liu P","Song Y","Liu Y","Ying L","Quan K","Yu G","Fan Z","Zhu W
BACKGROUND:The regulation of vascular smooth muscle cell (VSMC) phenotype plays an important role in intracranial aneurysm (IA) formation and progression. However, the underlying mechanism remains unclear. Metformin is a 5' AMP-activated protein kinase (AMPK) agonist that has a protective effect on vasculature. The present study investigated whether metformin modulates VSMC phenotype switching via the AMPK/acetyl-CoA carboxylase (ACC) pathway during IA pathogenesis. METHODS:Adult male Sprague-Dawley rats (n = 80) were used to establish an elastase-induced IA model. The effects of metformin on AMPK activation and VSMC phenotype modulation were examined. We also established a platelet-derived growth factor (PDGF)-BB-induced VSMC model and analyzed changes in phenotype including proliferation, migration, and apoptosis as well as AMPK/ACC axis activation under different doses of metformin, AMPK antagonist, ACC antagonist, and their combinations. RESULTS:Metformin decreased the incidence and rupture rate of IA in the rat model and induced a switch in VSMC phenotype from contractile to synthetic through activation of the AMPK/ACC pathway, as evidenced by upregulation of VSMC-specific genes and decreased levels of pro-inflammatory cytokines. AMPK/ACC axis activation inhibited the proliferation, migration, and apoptosis of VSMCs, in which phenotypic switching was induced by PDGF-BB. CONCLUSIONS:Metformin protects against IA formation and rupture by inhibiting VSMC phenotype switching and proliferation, migration, and apoptosis. Thus, metformin has therapeutic potential for the prevention of IA.
背景: 血管平滑肌细胞 (VSMC) 表型的调节在颅内动脉瘤 (IA) 的形成和进展中起重要作用。然而，潜在的机制仍不清楚。二甲双胍是一种 5 'AMP 激活的蛋白激酶 (AMPK) 激动剂，对脉管系统具有保护作用。本研究探讨了在 IA 发病过程中，二甲双胍是否通过 AMPK/乙酰辅酶a 羧化酶 (ACC) 途径调节 VSMC 表型转换。 方法: 采用成年雄性 Sprague-Dawley 大鼠 (n = 80) 建立弹性蛋白酶诱导的 IA 模型。检测二甲双胍对 AMPK 活化和 VSMC 表型调节的影响。我们还建立了血小板衍生生长因子 (PDGF)-BB 诱导的 VSMC 模型，分析了表型变化包括增殖、迁移、和凋亡以及不同剂量二甲双胍、 AMPK 拮抗剂、 ACC 拮抗剂及其组合下的 AMPK/ACC 轴激活。 结果: 二甲双胍降低了大鼠模型 IA 的发生率和破裂率，并通过激活 AMPK/ACC 通路诱导 VSMC 表型从收缩到合成的转换,VSMC 特异性基因的上调和促炎细胞因子水平的降低证明了这一点。AMPK/ACC 轴激活抑制 VSMCs 的增殖、迁移和凋亡，其中表型转换是由 PDGF-BB 诱导的。 结论: 二甲双胍通过抑制 VSMC 表型转换和增殖、迁移和凋亡来保护 IA 形成和破裂。因此，二甲双胍具有预防 IA 的治疗潜力。
METHODS:PURPOSE:To generate a preclinical model of isocitrate dehydrogenase (IDH) mutant gliomas from glioma patients and design a MRS method to test the compatibility of 2-hydroxyglutarate (2HG) production between the preclinical model and patients. METHODS:Five patient-derived xenograft (PDX) mice were generated from two glioma patients with IDH1 R132H mutation. A PRESS sequence was tailored at 9.4 T, with computer simulation and phantom analyses, for improving 2HG detection in mice. 2HG and other metabolites in the PDX mice were measured using the optimized MRS at 9.4 T and compared with 3 T MRS measurements of the metabolites in the parental-tumor patients. Spectral fitting was performed with LCModel using in-house basis spectra. Metabolite levels were quantified with reference to water. RESULTS:The PRESS TE was optimized to be 96 ms, at which the 2HG 2.25 ppm signal was narrow and inverted, thereby leading to unequivocal separation of the 2HG resonance from adjacent signals from other metabolites. The optimized MRS provided precise detection of 2HG in mice compared to short-TE MRS at 9.4 T. The 2HG estimates in PDX mice were in excellent agreement with the 2HG measurements in the patients. CONCLUSION:The similarity of 2HG production between PDX models and parental-tumor patients indicates that PDX tumors retain the parental IDH metabolic fingerprint and can serve as a preclinical model for improving our understanding of the IDH-mutation associated metabolic reprogramming.
METHODS:BACKGROUND:Gliomas consist of a heterogeneous group of tumors. This study aimed to report the incidences of O6-methylguanine-DNA-methyltransferase (MGMT) promoter methylation, 1p19q co-deletion, isocitrate dehydrogenase (IDH) gene mutations, and inactivating mutations of alpha-thalassemia/mental retardation syndrome X-linked (ATRX) in high-grade gliomas in an ethnically diverse population. METHODS:Records of patients who underwent surgery for high-grade gliomas from January 2013 to March 2017 at our institution were obtained. The patients' age, gender, ethnicity, Karnofsky Performance Scale (KPS) score, ability to perform activities of daily living (ADLs), tumor location and biomarkers status were recorded. Data were analyzed using chi-square and Mann-Whitney U tests, Kaplan-Meier estimates and log-rank test. RESULTS:181 patients were selected (56 with grade III gliomas, 125 with grade IV gliomas). In the grade III group, 55% had MGMT promoter methylation, 41% had 1p19q co-deletion, 35% had IDH1 mutation and none had ATRX loss. In the grade IV group, 30% had MGMT promoter methylation, 2% had 1p19q co-deletion, 15% had IDH1 mutation and 8% had ATRX loss. After adjusting for effects of age, surgery and pre-operative ADL statuses, only MGMT promoter methylation was found to be significantly associated with longer overall survival time in grade III (p = 0.024) and IV patients (p = 0.006). CONCLUSIONS:The incidences of MGMT promoter methylation and IDH1 mutation were found to be comparable to globally reported rates, but those of 1p19q co-deletion and ATRX loss seemed to be lower in our cohort. MGMT promoter methylation was associated with increased overall survival in our cohort and might serve as favorable prognostic factor.
METHODS:BACKGROUND:Glioblastoma multiforme is a CNS cancer characterized by diffuse infiltrative growth, aggressive clinical behavior and very poor prognosis. The state-of-art clinical approach to this disease consists of surgical resection followed by radiotherapy plus concurrent and adjuvant chemotherapy with temozolomide. Tumor recurrence occurs in virtually all cases, therefore, despite any treatment, the median survival is very low (14.6 months), which makes the approach to these patients a challenging clinical issue. MAIN BODY:The escalating costs and times required for new medications to reach the bedside make repurposing or repositioning of old drugs, when scientific bases allow their use in other pathologies, an appealing strategy. Here, we analyze a number of literature data concerning the antipsychotic chlorpromazine, the founder of the phenothiazines class of drugs, a medication widely used in the clinics for approximately 60 years. The drug exerts its effects on psychiatric patients by interfering with the dopamine receptor D2, although more recent pharmacodynamics studies ascribe chlorpromazine a series of biological effects on cancer cells, all converging in hindering also glioblastoma survival capabilities. SHORT CONCLUSIONS:On these bases, and assisted by the information on the well-established chlorpromazine toxicity and dosage in humans, we designed a Phase II clinical trial involving the combination of chlorpromazine with the standard treatment, temozolomide, in the adjuvant phase of the therapeutic protocol. Patients displaying hypo-methylation of the MGMT gene, and thus intrinsically resistant to temozolomide, will be enrolled. The endpoints of this study are the analysis of toxicity and clinical activity, as evaluated in terms of Progression-Free Survival, of the association of chlorpromazine with the first-line treatment for this very serious form of cancer.