Hyaluronan (HA) is an extracellular matrix component that regulates a variety of physiological and pathological processes. The function of HA depends both on its overall amount and on its size, properties that are controlled by HA synthesizing and degrading enzymes. The lack of inhibitors that can specifically block individual HA degrading enzymes has hampered attempts to understand the contribution of individual hyaluronidases to different physiological and pathological processes. CEMIP is a recently discovered hyaluronidase that cleaves HA through mechanisms and under conditions that are distinct from those of other hyaluronidases such as HYAL1 or HYAL2. The role of its hyaluronidase activity in physiology and disease is poorly understood. Here, we characterized a series of sulfated HA derivatives (sHA) with different sizes and degrees of sulfation for their ability to inhibit specific hyaluronidases. We found that highly sulfated sHA derivatives potently inhibited CEMIP hyaluronidase activity. One of these compounds, designated here as sHA3.7, was characterized further and shown to inhibit CEMIP with considerable selectivity over other hyaluronidases. Inhibition of CEMIP with sHA3.7 in fibroblasts, which are the main producers of HA in the interstitial matrix, increased the cellular levels of total and high molecular weight HA, while decreasing the fraction of low molecular weight HA fragments. Genetic deletion of CEMIP in mouse embryonic fibroblasts (MEFs) produced analogous results and confirmed that the effects of sHA3.7 on HA levels were mediated by CEMIP inhibition. Importantly, both CEMIP deletion and its inhibition by sHA3.7 suppressed fibroblast proliferation, while promoting differentiation into myofibroblasts, as reflected in a lack of CEMIP in myofibroblasts within skin wounds in experimental mice. By contrast, adipogenic and osteogenic differentiation were attenuated upon CEMIP loss or inhibition. Our results demonstrate the importance of CEMIP for the HA metabolism, proliferation and differentiation of fibroblasts, and suggest that inhibition of CEMIP with sulfated HA derivatives such as sHA3.7 has potential utility in pathological conditions that are dependent on CEMIP function.

透明质酸 (HA) 是一种细胞外基质成分，可调节多种生理和病理过程。HA 的功能取决于其总量和大小，由 HA 合成和降解酶控制的特性。缺乏可以特异性阻断单个 HA 降解酶的抑制剂阻碍了了解单个透明质酸酶对不同生理和病理过程的贡献的尝试。CEMIP 是最近发现的一种透明质酸酶，它通过与其他透明质酸酶（如 H​​YAL1 或 HYAL2）不同的机制和条件切割 HA。其透明质酸酶活性在生理和疾病中的作用知之甚少。这里，我们表征了一系列具有不同大小和硫酸化程度的硫酸化 HA 衍生物 (sHA)，因为它们具有抑制特定透明质酸酶的能力。我们发现高度硫酸化的 sHA 衍生物有效地抑制了 CEMIP 透明质酸酶的活性。这些化合物中的一种，在此指定为 sHA3.7，进一步表征并显示其抑制 CEIP 具有比其他透明质酸酶具有相当大的选择性。sHA3.7 在成纤维细胞中抑制 CEMIP 是间质基质中 HA 的主要产生者，增加了总和高分子量 HA 的细胞水平，同时降低了低分子量 HA 片段的分数。小鼠胚胎成纤维细胞 (MEF) 中 CEMIP 的遗传缺失产生了类似的结果，并证实 sHA3.7 对 HA 水平的影响是由 CEMIP 抑制介导的。重要的，sHA3.7 的 CEIP 缺失及其抑制均抑制了成纤维细胞增殖，同时促进了向肌成纤维细胞的分化，这反映在实验小鼠皮肤伤口内的肌成纤维细胞中缺乏 CEMIP。相比之下，脂肪形成和成骨分化在 CEIP 损失或抑制时减弱。我们的结果证明了 CEMIP 对 HA 代谢、成纤维细胞增殖和分化的重要性，并表明用硫酸化 HA 衍生物如 sHA3.7 抑制 CEMIP 在依赖于 CEMIP 功能的病理条件下具有潜在用途。在 CEIP 丢失或抑制后，脂肪形成和成骨分化减弱。我们的结果证明了 CEMIP 对 HA 代谢、成纤维细胞增殖和分化的重要性，并表明用硫酸化 HA 衍生物如 sHA3.7 抑制 CEMIP 在依赖于 CEMIP 功能的病理条件下具有潜在用途。在 CEIP 丢失或抑制后，脂肪形成和成骨分化减弱。我们的结果证明了 CEMIP 对 HA 代谢、成纤维细胞增殖和分化的重要性，并表明用硫酸化 HA 衍生物如 sHA3.7 抑制 CEMIP 在依赖于 CEMIP 功能的病理条件下具有潜在用途。