J Exp Clin Cancer Res|周晓阳团队揭示缓解PD-1/PD-L1抑制剂相关心脏毒性的分子机制

2022年8月3日 0条评论 275次阅读 0人点赞

最新细胞功能及机制文献分享

上期文章已经综述了PD-1或PD-L1的免疫检查点抑制剂（ICIs）在抗肿瘤治疗中取得的成绩与缺陷。PD-1/PD-L1抑制剂诱发的广谱免疫相关不良事件（irAE），其中心脏毒性是最致命的不良反应。ICI相关心脏毒性事件以不同形式发生，包括心肌炎、心肌病和心肌纤维化，且伴有心肌细胞凋亡的心肌炎是最重要的临床和病理特征之一。因此，减少全身炎症克服PD-1/PD-L1抑制剂诱导的心脏毒性（尤其是心肌炎）具有临床重要性。

2022年1月3日，武汉大学人民医院心内科周晓阳团队在Journal of Experimental and Clinical Cancer Research上发表了题为“Prevotellaceae produces butyrate to alleviate PD-1/PD-L1 inhibitor-related cardiotoxicity via PPARα-CYP4X1 axis in colonic macrophages”的研究论文。本研究旨在调查微生物群-宿主相互作用是否会导致PD-1/PD-L1抑制剂相关心脏毒性。结果证实，肠道屏障功能障碍通过下调butyrate-PPARα-CYP4X1信号通路，进而上调结肠巨噬细胞中的促炎因子TNF-α和IL-1β，从而放大PD-1抑制剂相关心脏毒性。团队指出，靶向肠道微生物群使结肠巨噬细胞极化远离M1样表型可为PD-1/PD-L1抑制剂相关心脏毒性提供潜在的治疗策略。

有研究显示，肠道微生物群的改变在心血管疾病引发的炎症反应中起着重要作用，肠道微生物群代谢物短链脂肪酸（SCFA），例如butyrate，具有抗炎特性。临床上，采用粪便移植调控肠道微生物群可提高PD-1/PD-L1抑制剂的疗效。然而，肠道微生物群及其代谢物（包括butyrate）的处理是否可以防止PD-1/PD-L1抑制剂诱导的心肌细胞凋亡和心脏毒性仍不清楚。

巨噬细胞是自身免疫和自身炎症疾病过程中炎症介质的主要生产者，PD-1抑制剂可通过将心脏巨噬细胞极化为M1样表型来诱导心脏损伤。团队前期研究发现，结肠巨噬细胞是结肠中数量最多的白细胞之一，可加重心脏毒性，且抑制CYP4X1后，可促使肿瘤相关巨噬细胞重新极化为M1表型，并上调M1样因子TNF-α和IL-1β。

在此项研究中，团队首先在黑色素瘤小鼠中测量了肠道微生物群失调以及低butyrate量对PD-1/PD-L1抑制剂相关心脏毒性的影响；其次，研究了M1样结肠巨噬细胞衍生因子IL-1β和TNF-α是否有助于PD-1/PD-L1抑制剂诱导的心肌细胞凋亡和心脏毒性；最后，探索了肠道微生物群失调是否通过butyrate-CYP4X1轴的下调来上调结肠巨噬细胞中的促炎因子TNF-α和IL-1β。

在BMS-1诱导心脏毒性的实验中，团队观察到肠道屏障损伤和肠道微生物群失调，其特征是普氏菌属（Prevotellaceae）和理研菌属（Rikenellaceae）缺失，埃希氏-志贺氏菌属（Escherichia-Shigella）和瘤胃球菌属（Ruminococcaceae）增加，并伴随低butyrate产量和结肠巨噬细胞M1样极化。粪便微生物群移植反映了BMS-1对心肌细胞凋亡和心脏毒性的影响，而巨噬细胞消耗和TNF-α和IL-1β的中和大大减弱了BMS-1诱导的心脏毒性。接下来的研究显示，给予洛氏普氏菌（prevotella loescheii）或补充butyrate后，减轻了PD-1/PD-L1抑制剂相关的心脏毒性。机制上，肠道微生物群失调通过下调PPARα-CYP4X1信号通路，进而促进结肠巨噬细胞M1样极化和促炎因子TNF-α和IL-1β的产生。

《J Exp Clin Cancer Res|周晓阳团队揭示缓解PD-1/PD-L1抑制剂相关心脏毒性的分子机制》

图普雷沃氏菌科上调结肠巨噬细胞中Butyrate-PPARα-CYP4X1信号轴，减轻PD-1/PD-L1抑制剂相关心脏毒性示意图。

期刊及DOI号

J Exp Clin Cancer Res. 2022 Jan 3.

doi: 10.1186/s13046-021-02201-4.

题目

Prevotellaceae produces butyrate to alleviate PD-1/PD-L1 inhibitor-related cardiotoxicity via PPARα-CYP4X1 axis in colonic macrophages

摘要

背景：Immune checkpoint inhibitor-related cardiotoxicity is one of the most lethal adverse effects, and thus, the identification of underlying mechanisms for developing strategies to overcome it has clinical importance. This study aimed to investigate whether microbiota-host interactions contribute to PD-1/PD-L1 inhibitor-related cardiotoxicity.

方法：A mouse model of immune checkpoint inhibitor-related cardiotoxicity was constructed by PD-1/PD-L1 inhibitor BMS-1 (5 and 10 mg/kg), and cardiomyocyte apoptosis and cardiotoxicity were determined by hematoxylin and eosin, Masson’s trichome and TUNEL assays. 16S rRNA sequencing was used to define the gut microbiota composition. Gut microbiota metabolites short-chain fatty acids (SCFAs) were determined by HPLC. The serum levels of myocardial enzymes (creatine kinase, aspartate transaminase, creatine kinase-MB and lactate dehydrogenase) and the production of M1 factors (TNF-α and IL-1β) were measured by ELISA. The colonic macrophage phenotype was measured by mmunofluorescence and qPCR. The expression of Claudin-1, Occludin, ZO-1 and p-p65 was measured by western blot. The gene expression of peroxisome proliferator-activated receptor α (PPARα) and cytochrome P450 (CYP) 4X1 was determined using qPCR. Statistical analyses were performed using Student’s t-test for two-group com-parisons, and one-way ANOVA followed by Student–Newman–Keul test for multiple-group comparisons.

结果：We observed intestinal barrier injury and gut microbiota dysbiosis characterized by Prevotellaceae and Rikenellaceae genus depletion and Escherichia-Shigella and Ruminococcaceae genus enrichment, accompanied by low butyrate production and M1-like polarization of colonic macrophages in BMS-1 (5 and 10 mg/kg)-induced cardiotoxicity. Fecal microbiota transplantation mirrored the effect of BMS-1 on cardiomyocyte apoptosis and cardiotoxicity, while macrophage depletion and neutralization of TNF-α and IL-1β greatly attenuated BMS-1-induced cardiotoxicity. Importantly, Prevotella loescheii recolonization and butyrate supplementation alleviated PD-1/PD-L1 inhibitor- relared cardiotoxicity. Mechanistically, gut microbiota dysbiosis promoted M1-like polarization of colonic macrophages and the production of proinflammatory factors TNF-α and IL-1β through downregulation of PPARα-CYP4X1 axis.

结论：Intestinal barrier dysfunction amplifies PD-1/PD-L1 inhibitor-related cardiotoxicity by upregulating proinflammatory factors TNF-α and IL-1β in colonic macrophages via downregulation of butyrate-PPARα-CYP4X1 axis. Thus, targeting gut microbiota to polarize colonic macrophages away from the M1-like phenotype could provide a potential therapeutic strategy for PD-1/PD-L1 inhibitor-related cardiotoxicity.

关键词：PD-1/PD-L1 inhibitors, Cardiotoxicity, Gut microbiota, The colonic macrophage, CYP4X1