Amelioration of atherosclerosis in apolipoprotein E-deficient mice by combined RNA interference of lipoprotein-associated phospholipase A2 and YKL-40

Abstract

To test the hypothesis that combined RNA interference (RNAi) of lipoprotein-associated phospholipase A2 (Lp-PLA2) and YKL-40 is superior to RNAi of Lp-PLA2 or YKL-40 alone in ameliorating atherosclerosis. A total of 120 apolipoprotein E-deficient mice (apoE-/- mice) were randomly divided into five groups, including the vehicle alone, scrambled RNAi, Lp-PLA2 RNAi, YKL-40 RNAi, and combined Lp-PLA2 and YKL-40 RNAi groups. Constrictive collars were used to induce plaque formation. Lp-PLA2 RNAi and YKL-40 RNAi viral suspensions were transduced into carotid plaques of the mice. Carotid plaques were harvested for histological analysis four weeks after viral vector transduction. Inflammatory gene expression in the plasma and atherosclerotic plaques was determined by ELISA and real-time PCR. Four weeks after RNAi, the serum concentration and plaque mRNA expression of Lp-PLA2 and YKL-40 were remarkably attenuated, leading to reduced inflammatory gene expression. Plaques from the Lp-PLA2 or YKL-40 RNAi group showed lower lipid content, higher collagen content, increased fibrous cap thickness, and lower mRNA expressions of MCP-1 and MMP-8 than than those in the vehicle and scramble groups. When compared with the isolated Lp-PLA2 or YKL-40 RNAi group, the combined Lp-PLA2 and YKL-40 RNAi group exhibited higher collagen content and fibrous cap thickness, and lower lipid content and local inflammation. The beneficial effects of RNAi were independent of the plasma lipoprotein profile. Combined RNAi of Lp-PLA2 and YKL-40 is superior to RNAi of Lp-PLA2 or YKL-40 alone in ameliorating atherosclerosis.

Neprilysin Inhibitor–Angiotensin II Receptor Blocker Combination Therapy (Sacubitril/valsartan) Suppresses Atherosclerotic Plaque Formation and Inhibits Inflammation in Apolipoprotein E- Deficient Mice

“…After anesthesia (40 mg/kg pentobarbital sodium i.p.) a constrictive silastic tube (0.30 mm) was applied to elicit plaque formation 1,11,12 . The mice were divided into three groups (n = 24 in each group): the control group, the valsartan group and the LCZ696 group.…”

“…Total RNA from the cells or the carotid arteries was extracted using Trizol reagent in accordance with the supplier’s instructions (CoWin Bioscience). qPCR analysis was conducted as described previously 1,11,12 . The relative expressions of IL-6, MCP-1 and MMP-8 mRNAs were quantified using SYBR green with the ABI Prism 7500 sequence detection system.…”

“…Atherosclerosis, a multi-factorial disease intertwined with inflammation, accounts for the majority of morbidity and mortality worldwide 1 . The renin angiotensin system (RAS) is tightly connected with the pathophysiology of atherosclerosis and its clinical complications 2 .…”

Lipoprotein‐associated phospholipase A2: The story continues

“…152 In addition, downregulating the expression of the PLA2G7 gene by RNA interference could induce ameliorative inflammation and atherosclerosis in apolipoprotein E-deficient mice. 153 Taken together, these findings indicate that Lp-PLA2 might be crucial during the development of atherosclerosis and in determining plaque instability via inflammatory pathways.…”

“…Furthermore, many large‐scale epidemiological studies have found that elevated plasma Lp‐PLA2 levels are associated with an increased risk of coronary disease, stroke, and/or mortality, further substantiating the proatherogenic role of Lp‐PLA2 . In addition, downregulating the expression of the PLA2G7 gene by RNA interference could induce ameliorative inflammation and atherosclerosis in apolipoprotein E‐deficient mice . Taken together, these findings indicate that Lp‐PLA2 might be crucial during the development of atherosclerosis and in determining plaque instability via inflammatory pathways.…”