髌下脂肪垫在骨关节炎中的特征：一项组织病理学和分子研究。

Infrapatellar fat pad features in osteoarthritis: a histopathological and molecular study.

机构信息

Rheumatology Unit, Department of Medicine - DIMED, University Hospital of Padova, Padova.

Laboratory of Immunorheumatology and Tissue Regeneration/RAMSES, Rizzoli Orthopedic Research Institute, Bologna.

出版信息

Rheumatology (Oxford). 2017 Oct 1;56(10):1784-1793. doi: 10.1093/rheumatology/kex287.

DOI:10.1093/rheumatology/kex287

PMID:28957567

Abstract

OBJECTIVE

The infrapatellar fat pad (IFP) is considered a local producer of adipocytokines, suggesting a potential role in OA. The objective of this study was to evaluate the histopathological and molecular characteristics of OA IFPs compared with controls.

METHODS

The histopathological characteristics of IFPs were evaluated in patients undergoing total knee replacements and in control patients (without OA), considering the following parameters: presence of inflammatory cells, vascularization, adipose lobules dimension and thickness of the interlobular septa. Immunohistochemistry was performed to evaluate VEGF, monocyte chemotactic protein 1 (MCP-1) and IL-6 proteins. Quantitative real time PCR was performed to evaluate the expression levels of adipocytokines in the OA IFPs.

RESULTS

OA IFPs showed an increase in inflammatory infiltration, vascularization and thickness of the interlobular septa compared with controls. VEGF, MCP-1 and IL-6 proteins were higher in OA IFPs compared with in controls. Inflammatory infiltration, hyperplasia, vascularization and fibrosis were increased in OA IFP synovial membranes compared with in those of controls. VEGF protein levels were associated with an increased number of vessels in the OA IFPs, while MCP-1 and IL-6 protein levels were associated with higher grades of inflammatory infiltration. Leptin levels were positively correlated with adiponectin and MCP-1expression, while adiponectin positively correlated with peroxisome proliferative activated receptor gamma, MCP-1 and IFP vascularity. MCP-1 showed a positive correlation with peroxisome proliferative activated receptor gamma. IFP lobules dimensions were positively correlated with IL-6 expression and negatively with thickness of interlobular septa. VEGF mRNA levels were positively correlated with increased synovial vascularity.

CONCLUSIONS

OA IFPs and synovial membranes are more inflamed, vascularized and fibrous compared with those of control patients (without OA).

摘要

目的

髌下脂肪垫（IFP）被认为是脂肪细胞因子的局部产生者，这表明其在 OA 中具有潜在作用。本研究的目的是评估与对照相比 OA IFP 的组织病理学和分子特征。

方法

评估了接受全膝关节置换术的患者和对照患者（无 OA）的 IFP 的组织病理学特征，考虑了以下参数：炎症细胞的存在、血管化、脂肪小叶的尺寸和小叶间隔的厚度。进行免疫组织化学染色以评估 VEGF、单核细胞趋化蛋白 1（MCP-1）和 IL-6 蛋白。进行定量实时 PCR 以评估 OA IFP 中的脂肪细胞因子的表达水平。

结果

与对照相比，OA IFP 显示出炎症浸润、血管化和小叶间隔厚度增加。与对照相比，OA IFP 中的 VEGF、MCP-1 和 IL-6 蛋白水平更高。与对照相比，OA IFP 滑膜中的炎症浸润、增生、血管化和纤维化增加。OA IFP 中的 VEGF 蛋白水平与血管数量增加相关，而 MCP-1 和 IL-6 蛋白水平与炎症浸润程度增加相关。瘦素水平与脂联素和 MCP-1 表达呈正相关，而脂联素与过氧化物酶体增殖物激活受体 γ、MCP-1 和 IFP 血管生成呈正相关。MCP-1 与过氧化物酶体增殖物激活受体 γ 呈正相关。IFP 小叶尺寸与 IL-6 表达呈正相关，与小叶间隔厚度呈负相关。VEGF mRNA 水平与增加的滑膜血管生成呈正相关。