The role of BHLHB2 in Scleroderma-Associated Lung Fibrosis

BHLHB2在硬皮病相关性肺纤维化中的作用 硬皮病/系统性硬化症(SSC)是一种纤维化的多系统风湿性疾病，与 细胞外基质(ECM)成分的沉积，如胶原和纤维连接蛋白。主要的和 SSC的致命并发症是肺纤维化(PF)，目前的治疗方法对其略微有效。IL-6 是一种在SSC成纤维细胞中过量产生的促炎和促纤维化细胞因子。同样，胰岛素样生长 胰岛素样生长因子(IGF)-II是IGF家族的一员，在SSC成纤维细胞中过量产生，并与 肺纤维化的发展。我们的实验室已经表明，在两个SSc肺组织中，IGF-II水平都增加了 以及来源于它们的原代成纤维细胞，IGF-II诱导正常肺(NL)的纤维化反应 成纤维细胞。IGF-II增加胶原、纤维连接蛋白和促纤维化转化生长因子β2的水平 (转化生长因子2)。在这个应用中，我们证明了IL-6增加了IGF-II的mRNA水平。基因芯片分析技术的研究 IGF-II诱导NL成纤维细胞表达碱性螺旋-环-螺旋转录因子 家族成员BHLHB2，已知的昼夜节律、脂肪生成和成纤维细胞自噬的调节因子。 我们的初步数据进一步表明，IL-6和IGF-II都增加了NL成纤维细胞的核BHLHB2水平。 我们证明BHLHB2的激活是几种促纤维化的下游介质之间的共同纽带 治疗药物：转化生长因子、白介素6和胰岛素样生长因子II。沉默BHLHB2下调IGF-II的表达。IGF-II通过信号途径诱导BHLHB2 通过胰岛素受体。因此，我们的中心假设是BHLHB2促进了 ECM基因水平升高导致硬皮病相关性肺纤维化。我们的目标是勾勒出 BHLHB2在系统性硬化症肺纤维化发展中的作用：(1)确定IL-2的作用机制。 6和IGF-II对BHLHB2的调控，比较IGF-II和IL-2在单细胞RNA序列中的差异表达基因 6刺激正常肺；(2)阐明BHLHB2在肺纤维化中的作用。这些目标与 国家心肺血液研究所的使命，因为它们将为 解决IGF-II引起的遗传失调与发育之间相互作用的翻译问题 与SSC相关的Pf。我们设想，我们的工作将为阻断IL-6和IGF-II的治疗提供理论基础 同时发挥抑制SSc肺纤维化进展的作用。由于SSC-PF的特征是激活 常见的纤维化途径和细胞外基质成分(胶原、纤维连接蛋白)的增加，这也是增加的 在以肺纤维化为特征的不同疾病中，我们的发现可能对肺纤维化有更广泛的意义。 与其他疾病相关的。除了有助于更深入地了解SSC-PF的机制外，这 Proposal在Carol博士的指导下为Ades boyega Timothy Adewale提供了严格的培训 Feghali-Bostwick，并为他配备了尖端技术，使他成为一名精明而熟练的医生- 科学家。

The Role of BHLHB2 in Scleroderma-Associated Lung Fibrosis Scleroderma/Systemic Sclerosis (SSc) is a fibrosing multi-system rheumatic disease associated with excessive deposition of extracellular matrix (ECM) components such as collagen and fibronectin. The predominant and fatal complication of SSc is Pulmonary Fibrosis (PF), for which current treatments are marginally effective. IL-6 is a pro-inflammatory and pro-fibrotic cytokine produced in excess in SSc fibroblasts. Likewise, insulin-like growth factor (IGF)-II, a member of the IGF family, is produced in excess in SSc fibroblasts and is implicated in the development of pulmonary fibrosis. Our lab has shown that IGF-II levels are increased in both SSc lung tissues and the primary fibroblasts derived from them, and that IGF-II induces a fibrotic response in normal lung (NL) fibroblasts. IGF-II increases levels of collagen, fibronectin, and the pro-fibrotic transforming growth factor beta-2 (TGF2). In this application, we demonstrate that IL-6 increases IGF-II mRNA levels. Microarray analysis of IGF-II-treated NL fibroblasts revealed increased expression of the Basic Helix-Loop-Helix transcription factor family member, BHLHB2, a known regulator of the circadian rhythm, adipogenesis, and fibroblast autophagy. Our preliminary data further show that both IL-6 and IGF-II increase nuclear BHLHB2 levels in NL fibroblasts. We show that BHLHB2 activation is a common link between, and downstream mediator for several profibrotic agents: TGF, IL-6 and IGF-II. Silencing BHLHB2 downregulated IGF-II. IGF-II induced BHLHB2 via signaling through the Insulin Receptor. Thus, our central hypothesis is that BHLHB2 contributes to the progression of Scleroderma-associated Lung Fibrosis by increasing levels of ECM genes. Our goal is to delineate the role of BHLHB2 in the development of lung fibrosis in Systemic Sclerosis by (1) identifying the mechanism by which IL- 6 and IGF-II regulate BHLHB2, comparing differentially-expressed genes in single cell RNASeq of IGF-II-and IL- 6 stimulated normal lung and (2) elucidating the role of BHLHB2 in lung fibrosis. These aims are consistent with the National Heart Lung and Blood Institute’s mission since they will provide important fundamental basis for addressing translational aspects of the interaction between genetic dysregulation due to IGF-II and development of SSc-associated PF. We envision that our work will provide a rationale for a therapy to block IL-6 and IGF-II function concomitantly to halt the progression of lung fibrosis in SSc. Since SSc-PF is characterized by activation of common fibrotic pathways and increases in ECM components (collagen, fibronectin), which are also increased in different diseases characterized by lung fibrosis, our findings may have wider implications for lung fibrosis associated with other diseases. In addition to facilitating a deeper understanding of mechanisms of SSc-PF, this proposal provides Adegboyega Timothy Adewale with a rigorous training under the mentorship of Dr. Carol Feghali-Bostwick and equips him with cutting-edge techniques to develop as an astute and skillful physician- scientist.