Joshi Rini, Rohil Vishwajeet, Arora Shvetambri, Kumar Ajit, Manral Sushma, Goel Sanjay, Priya Nivedita, Singh Prabhjot, Ponnan Prija, Chatterji Suvro, Dwarakanath Bilikere S, Saluja Daman, Rawat Diwan S, Prasad Ashok K, Saso Luciano, Kohli Ekta, DePass Anthony L, Bracke Marc E, Parmar Virinder S, Raj Hanumantharao G
V.P. Chest Institute, University of Delhi, Delhi 110 007, India.
Curr Top Med Chem. 2015;15(2):179-86.
The potential role of polyphenolic acetate (PA) in causing diverse biological and pharmacological actions has been well studied in our laboratory. Our investigations, for the first time, established the role of calreticulin transacetylase (CRTAase) in catalyzing the acetylation of nitric oxide synthase (NOS) by Pas leading to robust activation of NOS. 7, 8- Diacetoxy-4-methylcoumarin (DAMC) and other acetoxycoumarins augmented the expression of thioredoxin (TRX) and vascular endothelial growth factor (VEGF) in human peripheral blood mononuclear cells (PBMCs). These findings substantiated our earlier observations that DAMC was a superb inducer of angiogenesis. The enhanced expression of thioredoxin reductase (TRXR) and diminished expression of thioredoxin interacting protein (TRXIP) leading to increased expression and activity of TRX in PBMCs due to the action of DAMC was revealed by real time RT-PCR analysis. The possible activation of TRX due to acetylation was confirmed by the fact that TRX activity of PBMCs was enhanced by various acetoxycoumarins in tune with their affinities to CRTAase as substrates. DAMC caused enhanced production of NO by way of acetylation of NOS as mentioned above and thereby acted as an inducer of VEGF. Real time RT-PCR and VEGF ELISA results also revealed the overexpression of TRX. DAMC and other PAs were found to reduce the oxidative stress in cells as proved by significant reduction of intracellular ROS levels. Thus, the crucial role of TRX in DAMC-induced angiogenesis with the involvement of VEGF was established.
我们实验室已对多酚乙酸酯（PA）引发多种生物学和药理学作用的潜在作用进行了深入研究。我们的研究首次证实了钙网蛋白转乙酰酶（CRTAase）在催化PA对一氧化氮合酶（NOS）的乙酰化作用从而导致NOS强力激活方面的作用。7,8 - 二乙酰氧基 - 4 - 甲基香豆素（DAMC）和其他乙酰氧基香豆素可增强人外周血单个核细胞（PBMCs）中硫氧还蛋白（TRX）和血管内皮生长因子（VEGF）的表达。这些发现证实了我们早期的观察结果，即DAMC是血管生成的极佳诱导剂。实时逆转录 - 聚合酶链反应（RT - PCR）分析显示，由于DAMC的作用，PBMCs中硫氧还蛋白还原酶（TRXR）表达增强，硫氧还蛋白相互作用蛋白（TRXIP）表达减少，从而导致TRX的表达和活性增加。PBMCs的TRX活性因各种乙酰氧基香豆素作为底物与CRTAase的亲和力而增强，这一事实证实了乙酰化可能激活TRX。如上文所述，DAMC通过对NOS的乙酰化作用导致NO生成增加，从而作为VEGF的诱导剂。实时RT - PCR和VEGF酶联免疫吸附测定（ELISA）结果也显示TRX过表达。细胞内活性氧（ROS）水平显著降低证明，DAMC和其他PA可降低细胞中的氧化应激。因此，确立了TRX在DAMC诱导的血管生成中通过VEGF参与所起的关键作用。
