PO.TB10.14 · 肿瘤生物学
微生物刺激差异性调节星形胶质细胞和胶质母细胞瘤细胞的表型
Microbial stimuli differentially regulate astrocyte and glioblastoma cell phenotypes
作者与单位 Authors & Affiliations
摘要 Abstract
中文摘要
多形性胶质母细胞瘤（GBM）是一种星形细胞瘤，是最常见和最具侵袭性的原发性脑肿瘤。这些肿瘤呈现出复杂的分子谱和对治疗的耐药，从而导致预后不良。星形胶质细胞是脑中最丰富的细胞，维持血脑屏障（BBB）并支持代谢稳态。研究表明，当暴露于炎症时，它们可获得反应性表型，可能促进脑癌发生。然而，其在肿瘤发展中作用背后的机制仍不明确，凸显了进一步理解GBM中星形胶质细胞表型的必要性。来自牙周病致病菌牙龈卟啉单胞菌（Porphyromonas gingivalis，Pg）的脂多糖（LPS）是已知的内毒素，能够穿过BBB，诱导强烈的炎症反应。因此，理解常见微生物产物在脑微环境中的作用及其对GBM发病机制的影响至关重要。为评估这一反应，将星形胶质细胞和U87-GBM细胞培养并直接暴露于Pg-LPS、金黄色葡萄球菌脂磷壁酸（Sa-LTA）和大肠杆菌脂多糖（Ec-LPS）。还使用经Pg-LPS、Sa-LTA和Ec-LPC引发的星形胶质细胞条件培养基（ACM）进行了间接处理。在暴露24小时和48小时后，分别通过ELLA实验和免疫荧光（IF）测量细胞因子和蛋白表达。通过MTT实验评估活力。在24小时时，与其他处理相比，暴露于Pg-LPS显著增加了星形胶质细胞的代谢活性（p = 0.042），但在48小时时未观察到该效应。星形胶质细胞中增殖标志物Ki67的IF染色显示，用Pg-LPS处理24小时后显著增加（p = 0.033）。相比之下，经Pg-LPS引发的ACM处理48小时后，与未处理组（p = 0.007）、直接用Pg-LPS处理的U87-GBM细胞（p = 0.003）以及未引发的星形胶质细胞条件培养基（p = 0.024）相比，降低了GBM细胞的增殖。GBM细胞表达的Ki67水平始终高于所有星形胶质细胞处理组，且各处理组间活力保持不变。此外，经Pg-LPS引发的ACM呈现出可检测水平的IL-10、IFN-a2、IL-4和TGF-beta。我们的结果提示，Pg-LPS促进向抗炎表型的转变，并可能降低GBM细胞的增殖。需要进一步研究以阐明经Pg-LPS调节的星形胶质细胞如何调控GBM进展。
查看英文原文 English abstract
Glioblastoma multiforme (GBM), an astrocytoma, is the most prevalent and aggressive primary brain tumor. These tumors present with an intricate molecular profile and resistance to treatment, thus resulting in poor prognosis. Astrocytes, the most abundant cells in the brain, maintain the blood-brain barrier (BBB) and support metabolic homeostasis. Studies have shown that, when exposed to inflammation, they can acquire a reactive phenotype, possibly contributing brain carcinogenesis. However, the mechanisms behind their role in tumor development remain unclear, highlighting the need to further understand the phenotype of astrocytes in GBM. Lipopolysaccharides (LPS) from periodontal disease-causing pathogen Porphyromonas gingivalis (Pg) are known endotoxins capable of crossing the BBB, inducing strong inflammatory responses. Thus, understanding the role of common microbial products in the brain microenvironment, and their influence on GBM pathogenesis is key. To assess this response, astrocytes and U87-GBM cells were cultured and exposed directly to Pg-LPS, Staphylococcus aureus lipoteichoic acids (Sa-LTA) and Escherichia coli lipopolysaccharides (Ec-LPS). Indirect treatments were also performed using astrocyte-conditioned media (ACM) primed with Pg-LPS, Sa-LTA and Ec-LPC. After 24- and 48-hour exposures, cytokine and protein expression were measured by ELLA assays and immunofluorescence (IF) respectively. Viability was assessed via MTT Assay. At 24 hours, exposure to Pg-LPS significantly increased astrocyte metabolic activity when compared to other treatments (p = 0.042), though this effect was not observed at 48 hours. IF staining of proliferation marker Ki67 in astrocytes revealed a significant increase when treated with Pg-LPS (p = 0.033) for 24H. In contrast, Pg-LPS-primed ACM for 48H, decreased proliferation in GBM cells compared to untreated (p = 0.007), directly treated U87-GBM cells with Pg-LPS (p = 0.003), and not-primed astrocyte-conditioned media (p = 0.024). GBM cells expressed consistently higher levels of Ki67 than all astrocyte treatments and viability remained unchanged across treatments. Moreover, Pg-LPS-primed ACM presented detectable levels of IL-10, IFN-a2, IL-4 and TGF-beta. Our results suggest that Pg-LPS promotes a shift toward an anti-inflammatory phenotype and may reduce proliferation in GBM cells. Further studies are needed to elucidate how Pg-LPS-conditioned astrocytes modulate GBM progression.
利益披露 Disclosure
A. N. De Jesus-Carrasquillo, None..
C. M. Ramos-Lugo, None..
A. Serpa-Figueroa, None..
A. Soto-Nieves, None..
A. Y. Morlá-Sevilla, None..
Y. Corchado-Vargas, None..
J. M. Torres-Cruz, None..
Y. M. Cantres-Rosario, None.