Sullivan Stasia N, Altmann Nadine N, Brokken Matthew T, Durgam Sushmitha S
Department of Veterinary Clinical Sciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH, United States.
Front Vet Sci. 2020 Aug 5;7:486. doi: 10.3389/fvets.2020.00486. eCollection 2020.
Primary deep digital flexor tendon (DDFT) pathologies and those accompanying degenerative changes of navicular bone fibrocartilage are major causes of lameness associated with navicular disease. Intrasynovial corticosteroids are mainstay in the treatment due to the anti-inflammatory effects, but their effect on DDFT cell biosynthesis are unknown. The objective of this study was to investigate the effects of methylprednisolone acetate (MPA) on cells isolated from the dorsal fibrocartilaginous region of forelimb DDFTs (DDFT-derived cells) of 5 horses (aged 11-17 years). Non-adherent aggregate cultures were established from third passage cells over a 72 to 96-h duration prior to treating with medium containing 0 (control), 0.05 and 0.5 mg/mL MPA for 24 h. Tendon and cartilage extracellular matrix (ECM) related gene expression, cell aggregate and culture medium GAG contents, culture medium collagen and MMP-3 and-13 concentrations were measured. After 24 h of treatment, only the higher MPA concentration (0.5 mg/mL) significantly down-regulated tendon ECM related genes; whereas, both MPA doses significantly down-regulated cartilage ECM related genes. MPA treatment did not affect the total GAG content of DDFT-derived cells or total GAG, soluble collagen and MMP-3 and-13 contents in culture medium compared to untreated controls. Future studies to determine the response of DDFT-derived cells with longer exposure times to corticosteroids and in the presence of inflammatory cytokines are necessary. These results are a first step in assessing the effects of intrasynovial medications on equine DDFT, for which currently no information exists.
原发性指深屈肌腱（DDFT）病变以及伴随舟状骨纤维软骨退变的病变是与舟状骨病相关跛行的主要原因。由于具有抗炎作用，滑膜内注射皮质类固醇是治疗的主要手段，但其对DDFT细胞生物合成的影响尚不清楚。本研究的目的是调查醋酸甲泼尼龙（MPA）对5匹年龄在11至17岁马的前肢DDFT背侧纤维软骨区域分离的细胞（DDFT衍生细胞）的影响。在用含0（对照）、0.05和0.5mg/mL MPA的培养基处理24小时之前，从第三代细胞建立非贴壁聚集培养物，持续72至96小时。测量肌腱和软骨细胞外基质（ECM）相关基因表达、细胞聚集物和培养基糖胺聚糖（GAG）含量、培养基胶原蛋白以及MMP-3和-13浓度。处理24小时后，只有较高浓度的MPA（0.5mg/mL）显著下调肌腱ECM相关基因；而两种MPA剂量均显著下调软骨ECM相关基因。与未处理的对照相比，MPA处理不影响DDFT衍生细胞的总GAG含量或培养基中的总GAG、可溶性胶原蛋白以及MMP-3和-13含量。有必要进行进一步研究，以确定DDFT衍生细胞在更长时间暴露于皮质类固醇以及存在炎性细胞因子的情况下的反应。这些结果是评估滑膜内用药对马DDFT影响的第一步，目前尚无相关信息。
