CD38 通过影响软骨动态平衡驱动骨关节炎进展。

CD38 Drives Progress of Osteoarthritis by Affecting Cartilage Homeostasis.

机构信息

School of Stomatology, Zhejiang Chinese Medical University, Hangzhou, China.

Department of Orthopaedic Surgery, The First Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, China.

出版信息

Orthop Surg. 2022 May;14(5):946-954. doi: 10.1111/os.13258. Epub 2022 Apr 20.

DOI:10.1111/os.13258

PMID:35441488

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC9087467/

Abstract

OBJECTIVE

To observe expression of CD38, a key modulator of nicotinamide dinucleotide (NAD+) metabolism in mice with knee osteoarthritis, and protective effect of CD38 inhibition during the osteoarthritis (OA) development.

METHOD

The destabilization of the medial meniscus (DMM) model was performed in mice to mimic the process of OA. Immunofluorescence of CD38 was performed to evaluate its response during the OA process. Limb bud-derived mesenchymal cells were isolated for micromass culture. 100 nM or 1 μM CD38 inhibitor (78c) treatment for 14 days and CD38 sgRNA infection were then used to explore the effects of chondrogenic differentiation via Alcian blue staining. The expressions of chondrogenic markers were detected using RT-PCR and Western blot. To explore the protective effect of CD38 inhibitor on cartilage degradation during OA in vivo, a CD38 inhibitor was injected into the knee joint after DMM operations. Micro-CT analysis and Safranin O-fast green staining were used to evaluate subchondral bone micro-architecture changes and cartilage degeneration.

RESULTS

Compared to the control group, the CD38 expression in superficial cartilage was obviously increased in DMM group (P < 0.05). During the normal chondrogenic differentiation, the extracellular matrix formed and expression of Sox9, Col2, aggrecan increased apparently while CD38 expression decreased, which could be reversed with ablation of CD38 in limb bud-derived mesenchymal cells. Consistent with findings in vitro, CD38 blockage via CD38 inhibitor injection protected against osteosclerosis in medial subchondral bone and cartilage degeneration in DMM-induced experimental mice. Compared to the Sham group, DMM mice showed significantly increased values of BV and BV/TV in subchondral bone (P < 0.05) and Mankin score, which could be rescued by 78c treatment (P < 0.05). Also the CD38 inhibitor contributed to homeostasis of anabolism and catabolism by upregulating Sox9, Col2, aggrecan and downregulating Runx2, Col10 and Mmp13.

CONCLUSION

This study primarily implicates CD38 as an important regulator of chondrogenic differentiation. Inhibition of CD38 demonstrated protection against cartilage degeneration, which suggests that CD38 could be a potential therapeutic target for OA.

摘要

目的

观察 CD38 在膝骨关节炎小鼠中作为烟酰胺腺嘌呤二核苷酸（NAD+）代谢关键调节剂的表达，以及在骨关节炎（OA）发展过程中抑制 CD38 的保护作用。

方法

通过内侧半月板不稳定（DMM）模型在小鼠中模拟 OA 过程。进行 CD38 的免疫荧光染色以评估其在 OA 过程中的反应。分离肢芽衍生的间充质细胞进行微团培养。用 100 nM 或 1 μM CD38 抑制剂（78c）处理 14 天，并进行 CD38 sgRNA 感染，然后通过茜素蓝染色来探索软骨分化的影响。使用 RT-PCR 和 Western blot 检测软骨形成标志物的表达。为了探索 CD38 抑制剂在体内 OA 过程中对软骨降解的保护作用，在 DMM 手术后将 CD38 抑制剂注入膝关节。使用 micro-CT 分析和番红 O-fast 绿染色评估软骨下骨微观结构变化和软骨退化。

结果

与对照组相比，DMM 组浅层软骨中的 CD38 表达明显增加（P < 0.05）。在正常软骨形成分化过程中，细胞外基质形成，Sox9、Col2、聚集蛋白聚糖的表达明显增加，而 CD38 的表达减少，在肢芽衍生的间充质细胞中，CD38 的缺失可逆转这种情况。与体外研究结果一致，通过注射 CD38 抑制剂阻断 CD38 可防止内侧软骨下骨的骨质硬化和 DMM 诱导的实验小鼠的软骨退化。与 Sham 组相比，DMM 小鼠的软骨下骨的 BV 和 BV/TV 值明显增加（P < 0.05），Mankin 评分升高，而 78c 治疗可挽救这些变化（P < 0.05）。此外，CD38 抑制剂通过上调 Sox9、Col2、聚集蛋白聚糖，下调 Runx2、Col10 和 Mmp13，有助于维持合成代谢和分解代谢的平衡。