Song Min, Wang Youli, Annex Brian H, Popel Aleksander S
Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
Department of Medicine, Augusta University Medical College of Georgia, Augusta, GA 30912, USA.
Cytokine. 2025 Nov;195:157029. doi: 10.1016/j.cyto.2025.157029. Epub 2025 Sep 13.
Many diseases associated with angiogenesis involve inflammatory cytokine mediated responses. Targeting angiogenesis as a predominant strategy has shown limited effects in many contexts including peripheral arterial disease (PAD). One potential reason for the unsuccessful outcome is the interdependence between inflammation and angiogenesis. Inflammation-based therapies primarily target inflammatory cytokines such as interleukin-6 (IL-6) in T cells, macrophages, cancer cells, muscle cells. However, the mechanism of how these cytokines act on endothelial cells under PAD-specific hypoxia serum starvation (HSS) conditions are not well understood. Thus, we focus on one of the major inflammatory cytokines, IL-6, mediated intracellular signaling in endothelial cells under HSS conditions by conducting relevant in vitro experiments on human umbilical vein endothelial cells (HUVECs) and developing an experimentally validated computational model. Our model quantitatively characterized the effects of IL-6 classic and trans-signaling in activating the signal transducer and activator of transcription 3 (STAT3), phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt), and mitogen-activated protein kinase (MAPK) signaling to phosphorylate STAT3, extracellular regulated kinase (ERK) and Akt, respectively in endothelial cells under HSS condition. The trained and validated experiment-based computational model was used to characterize the dynamics of phosphorylated STAT3 (pSTAT3), Akt (pAkt), and ERK (pERK) in response to IL-6 classic and/or trans-signaling under HSS conditions. The model predicts that IL-6 classic and trans-signaling induced responses are dose dependent. In addition, IL-6 trans-signaling induces greater downstream signaling responses compared to classic signaling and plays a dominant role in the overall effects due to a tighter binding of the ligand and receptors and an abundant supply of soluble receptor sIL-6R because of the experimental setting. Moreover, our model identifies the species and kinetic parameters that specifically have a significant impact on the phosphorylation of STAT3, Akt, and ERK, which represent potential targets for the inflammatory cytokine mediated signaling and angiogenesis-based therapies under HSS conditions. Overall, the model predicts the effects of IL-6 classic and/or trans-signaling stimulation under HSS condition quantitatively and provides a framework for analyzing and integrating experimental data. More broadly, this model can be applied to identify potential targets that influence inflammatory cytokine mediated signaling in endothelial cells under HSS conditions and to investigate the effects of angiogenesis- and inflammation-based therapies specific to PAD.
许多与血管生成相关的疾病都涉及炎症细胞因子介导的反应。在包括外周动脉疾病（PAD）在内的许多情况下，将血管生成作为主要策略的治疗效果有限。治疗效果不佳的一个潜在原因是炎症与血管生成之间的相互依存关系。基于炎症的疗法主要针对T细胞、巨噬细胞、癌细胞、肌肉细胞中的炎性细胞因子，如白细胞介素-6（IL-6）。然而，在PAD特异性缺氧血清饥饿（HSS）条件下，这些细胞因子如何作用于内皮细胞的机制尚不清楚。因此，我们通过对人脐静脉内皮细胞（HUVECs）进行相关体外实验，并建立一个经过实验验证的计算模型，来研究主要炎性细胞因子之一IL-6在HSS条件下介导的内皮细胞内信号传导。我们的模型定量表征了IL-6经典信号和转信号在激活信号转导和转录激活因子3（STAT3）、磷脂酰肌醇3激酶/蛋白激酶B（PI3K/Akt）以及丝裂原活化蛋白激酶（MAPK）信号传导方面的作用，这些信号传导分别在HSS条件下使内皮细胞中的STAT3、细胞外调节蛋白激酶（ERK）和Akt磷酸化。经过训练和验证的基于实验的计算模型用于表征在HSS条件下，响应IL-6经典信号和/或转信号时，磷酸化的STAT3（pSTAT3）、Akt（pAkt）和ERK（pERK）的动态变化。该模型预测，IL-6经典信号和转信号诱导的反应呈剂量依赖性。此外，与经典信号相比，IL-6转信号诱导更强的下游信号反应，并且由于配体与受体的紧密结合以及实验设置中可溶性受体sIL-6R的大量供应，在整体效应中起主导作用。此外，我们的模型确定了对STAT3、Akt和ERK磷酸化有显著影响的特定物种和动力学参数，这些参数代表了HSS条件下炎性细胞因子介导的信号传导和基于血管生成的治疗的潜在靶点。总体而言，该模型定量预测了HSS条件下IL-6经典信号和/或转信号刺激的效果，并提供了一个分析和整合实验数据的框架。更广泛地说，该模型可用于识别在HSS条件下影响内皮细胞中炎性细胞因子介导的信号传导的潜在靶点，并研究针对PAD的基于血管生成和炎症的治疗效果。
