Galgoczi Erika, Jeney Florence, Gazdag Annamaria, Erdei Annamaria, Katko Monika, Nagy Domonkos M, Ujhelyi Bernadett, Steiber Zita, Gyory Ferenc, Berta Eszter, Nagy Endre V
Division of EndocrinologyDepartment of Internal Medicine, Faculty of Medicine, University of Debrecen, Debrecen, Hungary.
Department of OphthalmologyFaculty of Medicine, University of Debrecen, Debrecen, Hungary.
J Endocrinol. 2016 May;229(2):187-96. doi: 10.1530/JOE-15-0524. Epub 2016 Mar 15.
During the course of Graves' orbitopathy (GO), orbital fibroblasts are exposed to factors that lead to proliferation and extracellular matrix (ECM) overproduction. Increased levels of tissue plasminogen activator inhibitor type 1 (PAI-1 (SERPINE1)) might promote the accumulation of ECM components. PAI-1 expression is regulated by cell density and various cytokines and growth factors including transforming growth factorβ(TGF-β). We examined the effects of increasing cell densities and TGF-β on orbital fibroblasts obtained from GO patients and controls. Responses were evaluated by the measurement of proliferation, PAI-1 expression, and ECM production. There was an inverse correlation between cell density and the per cell production of PAI-1. GO orbital, normal orbital, and dermal fibroblasts behaved similarly in this respect. Proliferation rate also declined with increasing cell densities. Hyaluronan (HA) production was constant throughout the cell densities tested in all cell lines. In both GO and normal orbital fibroblasts, but not in dermal fibroblasts, TGF-β stimulated PAI-1 production in a cell density-dependent manner, reaching up to a five-fold increase above baseline. This has been accompanied by increased HA secretion and pericellular HA levels at high cell densities. Increasing cell density is a negative regulator of proliferation and PAI-1 secretion both in normal and GO orbital fibroblasts; these negative regulatory effects are partially reversed in the presence of TGF-β. Cell density-dependent regulation of PAI-1 expression in the orbit, together with the local cytokine environment, may have a regulatory role in the turnover of the orbital ECM and may contribute to the expansion of orbital soft tissue in GO.
在格雷夫斯眼眶病（GO）病程中，眼眶成纤维细胞会接触到导致其增殖和细胞外基质（ECM）过度产生的因素。组织纤溶酶原激活物抑制剂1（PAI-1（SERPINE1））水平升高可能会促进ECM成分的积累。PAI-1的表达受细胞密度以及包括转化生长因子β（TGF-β）在内的多种细胞因子和生长因子的调节。我们研究了细胞密度增加和TGF-β对从GO患者和对照组获取的眼眶成纤维细胞的影响。通过测量增殖、PAI-1表达和ECM产生来评估反应。细胞密度与PAI-1的单细胞产量之间呈负相关。在这方面，GO眼眶成纤维细胞、正常眼眶成纤维细胞和真皮成纤维细胞表现相似。增殖率也随着细胞密度的增加而下降。在所有测试的细胞系中，透明质酸（HA）产量在整个细胞密度范围内保持恒定。在GO和正常眼眶成纤维细胞中，但在真皮成纤维细胞中未观察到，TGF-β以细胞密度依赖性方式刺激PAI-1产生，最高可达基线水平以上五倍的增加。这伴随着高细胞密度下HA分泌增加和细胞周围HA水平升高。细胞密度增加是正常和GO眼眶成纤维细胞增殖和PAI-1分泌的负调节因子；在TGF-β存在的情况下，这些负调节作用会部分逆转。眼眶中PAI-1表达的细胞密度依赖性调节，连同局部细胞因子环境，可能在眼眶ECM的周转中起调节作用，并可能有助于GO中眼眶软组织的扩张。
