Department of Vascular Surgery, Tiantai People's Hospital of Zhejiang Province, Tiantai, China.
Eur Rev Med Pharmacol Sci. 2018 Oct;22(20):6991-6998. doi: 10.26355/eurrev_201810_16170.
To investigate the possible role of hox transcript antisense intergenic RNA (HOTAIR) in the pathogenesis of atherosclerosis and its underlying mechanism.
The expression of HOTAIR in peripheral blood lymphocytes of atherosclerosis (AS) and healthy controls was detected by quantitative Real-time-polymerase chain reaction (qRT-PCR). In vitro AS model was established by ox-LDL induction in Raw264.7 cells. Viability of Raw264.7 cells after ox-LDL induction was detected by cell counting kit-8 (CCK-8) assay. Levels of TC (total cholesterol), TG (triglyceride), LDL-C (low density lipoprotein cholesterol) and HDL-C (high density lipoprotein cholesterol) in Raw264.7 cells were detected by enzyme-linked immunosorbent assay (ELISA). Overexpression plasmid of HOTAIR was constructed. Levels of TG, TC, LDL-C, and HDL were detected again after HOTAIR overexpression by ELISA. CD68+ cells and CD168+ cells in Raw264.7 cells were detected by flow cytometry. Protein expressions of pro-inflammatory and anti-inflammatory genes were detected by Western blot. Lipid metabolism in Raw264.7 cells was evaluated by oil red O staining and Western blot, respectively. Finally, rescue experiments were conducted to explore the specific mechanism of HOTAIR in regulating AS development.
HOTAIR was lowly expressed in peripheral blood lymphocytes of AS patients and Raw264.7 cells induced by ox-LDL. Overexpression of HOTAIR upregulated adipose genes (PPARα and CPT-1) and downregulated lipogenesis genes (SREBP-1c and ACS). Besides, overexpression of HOTAIR decreased expressions of pro-inflammatory cytokines (TNF-α and IL-1β), but increased expressions of anti-inflammatory cytokines (IL-4 and IL-10). In the in vitro AS model, FXR1 was remarkably downregulated in Raw264.7 cells. HOTAIR reduced inflammatory response via promoting FXR1 expression in Raw264.7 cells. Rescue experiments showed that the effect of HOTAIR on nuclear factor-kappa B (NF-κB) pathway was reversed by FXR1 knockdown.
We found that TAIR was lowly expressed in AS patients. Overexpression of HOTAIR can reduce the lipid accumulation and inhibit inflammatory response by suppressing FXR1 via NF-κB pathway.
探讨反义基因间的 HOX 转录物 RNA（HOTAIR）在动脉粥样硬化发病机制中的可能作用及其潜在机制。
采用实时定量聚合酶链反应（qRT-PCR）检测动脉粥样硬化（AS）患者和健康对照者外周血淋巴细胞中 HOTAIR 的表达。采用 ox-LDL 诱导 Raw264.7 细胞建立体外 AS 模型。细胞计数试剂盒-8（CCK-8）法检测 ox-LDL 诱导后 Raw264.7 细胞的活力。酶联免疫吸附试验（ELISA）检测 Raw264.7 细胞中 TC（总胆固醇）、TG（甘油三酯）、LDL-C（低密度脂蛋白胆固醇）和 HDL-C（高密度脂蛋白胆固醇）水平。构建 HOTAIR 过表达质粒。再次通过 ELISA 检测 HOTAIR 过表达后 TG、TC、LDL-C 和 HDL 的水平。流式细胞术检测 Raw264.7 细胞中 CD68+细胞和 CD168+细胞。Western blot 法检测促炎和抗炎基因的蛋白表达。油红 O 染色和 Western blot 分别评估 Raw264.7 细胞的脂质代谢。最后，进行挽救实验以探讨 HOTAIR 调节 AS 发展的特定机制。
AS 患者外周血淋巴细胞和 ox-LDL 诱导的 Raw264.7 细胞中 HOTAIR 表达水平较低。HOTAIR 过表达上调脂肪基因（PPARα和 CPT-1），下调脂肪生成基因（SREBP-1c 和 ACS）。此外，HOTAIR 过表达降低促炎细胞因子（TNF-α和 IL-1β）的表达，增加抗炎细胞因子（IL-4 和 IL-10）的表达。在体外 AS 模型中，Raw264.7 细胞中 FXR1 表达明显下调。HOTAIR 通过促进 Raw264.7 细胞中 FXR1 的表达来减轻炎症反应。挽救实验表明，FXR1 敲低逆转了 HOTAIR 对核因子-κB（NF-κB）通路的影响。
我们发现 AS 患者中 HOTAIR 表达水平降低。HOTAIR 过表达通过 NF-κB 通路抑制 FXR1 表达，减少脂质积累，抑制炎症反应。
