NMAAP1调控HIF-1α介导的Warburg效应在巨噬细胞极化及抗肿瘤效应中的作用及机制研究

Intravesical BCG therapy has been successfully used in curing bladder cancer while macrophages (mφ) are the main involved cells, but their function and mechanism are unclear. When stimulated mφ with BCG, the expression of a novel protein NMAAP1 was increased ,which can induce mφ to polarize to M1 direction. The Warburg effect (aerobic glycolysis) occurs to BCG-stimulated mφ, and HIF-1α, which mediates this effect, modulates the mφ-to-M1 polarization. The results showed that anti-tumor effect of BCG-stimulated mφ was weakened when conditional knockout of HIF1α, while NMAAP1 could up-regulate the expression of HIF-1α and promote the release of lactate. Whether NMAAP1 plays a role through HIF-1α and its downstream glycolysis needs to be further explored. In this study, HIF-1α was used as an entry point to these research：1) to clarify the role of NMAAP1 in mφ polarization and its anti-tumor effect; 2) to investigate whether this effect is mediated through regulation of HIF-1α and its downstream glycolytic metabolism; 3) to study the mechanism by which NMAAP1 regulates HIF-1α deeply. This study will clarify the role of NMAAP1 in the regulation of HIF-1α between mφ polarization and it anti-tumor effect, and lay the foundation for the development of new anti-tumor drugs based on NMAAP1.

BCG可通过灌注疗法治疗膀胱癌，而巨噬细胞(mφ)为主要细胞，但怎样发挥作用及机制不清。BCG活化mφ后上调表达新型蛋白NMAAP1，能够促使mφ向M1方向极化。BCG刺激mφ后出现Warburg效应(有氧糖酵解)，介导该效应的HIF-1α可调节mφ向M1极化。前期结果发现BCG刺激HIF-1α mφ条件性缺失鼠后，mφ的抗肿瘤作用减弱，而NMAAP1又可以上调HIF-1α的表达，并促进乳酸的释放。那么NMAAP1是否通过HIF-1α及其下游糖酵解发挥作用有待深入探讨。本研究以HIF-1α为切入点，1)明确NMAAP1在mφ极化并发挥抗肿瘤效应中的作用;2)探讨这种作用是通过调节HIF-1α及其下游糖酵解代谢实现的;3)深入研究NMAAP1调节HIF-1α的机制。本研究将阐明NMAAP1调控HIF-1α在mφ极化并发挥抗肿瘤效应中的作用，同时为开发基于NMAAP1的新型抗肿瘤药物奠定基础。

卡介苗（BCG）灌注疗法可用于膀胱癌的治疗，而巨噬细胞为主要参与细胞，但怎样发挥作用及机制不清。BCG活化巨噬细胞后上调表达新型蛋白NMAAP1，能够促使巨噬细胞向M1型方向极化。糖酵解增强是活化免疫细胞的关键特征之一。巨噬细胞被诱导为M1型，存在有氧糖酵解，即Warburg效应，表现在：葡萄糖摄取增加，以及丙酮酸转化为乳酸。而NMAAP1能够促进乳酸的分泌，并上调糖酵解相关分子HIF-1α。那么NMAAP1是否能够调控巨噬细胞HIF-1α介导的糖酵解从而影响其向M1型方向极化并发挥抗肿瘤作用还不清楚。因此，我们从免疫代谢角度出发，通过体内及体外实验探讨了NMAAP1对于巨噬细胞糖酵解的影响及相关机制。.1）我们发现BCG能够刺激小鼠的BMDM向M1型极化并对肿瘤细胞产生杀伤作用，NMAAP1在此过程中发挥重要作用。当NMAAP1缺失后，小鼠的肿瘤体积变大，肿瘤内M1型巨噬细胞明显减少，体外实验也观察到同样的现象。此外，我们还发现NMAAP1可以维持巨噬细胞的M1表型。.2）NMAAP1促进巨噬细胞向M1型方向极化是通过影响Warburg效应实现的。NMAAP1可以促进乳酸、丙酮酸的释放，增强巨噬细胞的糖酵解，同时影响HIF-1α在内的糖酵解相关酶的表达。2-DG抑制糖酵解后，MNMAAP1促进巨噬细胞型向M1型方向极化并发挥抗肿瘤作用减弱。.3）HIF-1α缺失减弱了BCG促进巨噬细胞向M1型方向分化并发挥抗肿瘤作用。通过体内实验发现HIF-1α缺失后，小鼠肿瘤体积明显增大。当HIF-1α缺失小鼠的BMDM给予2-DG后，BCG促进巨噬细胞向M1型方向分化并发挥抗肿瘤作用明显减弱。.本研究明确了NMAAP1调控HIF-1α的表达进而影响其极化及抗肿瘤效应，为BCG的临床应用以及基于NMAAP1开发新型抗肿瘤药物奠定基础。