Stocco Elena, Belluzzi Elisa, Contran Martina, Boscolo-Berto Rafael, Picardi Edgardo, Guidolin Diego, Fontanella Chiara Giulia, Olivotto Eleonora, Filardo Giuseppe, Borile Giulia, Romanato Filippo, Ramonda Roberta, Ruggieri Pietro, Favero Marta, Porzionato Andrea, De Caro Raffaele, Macchi Veronica
Department of Neuroscience, Institute of Human Anatomy, University of Padova, Padova, Italy.
L.i.f.e.L.a.b. Program, Consorzio per la Ricerca Sanitaria, Padova, Italy.
Front Med (Lausanne). 2021 May 10;8:661403. doi: 10.3389/fmed.2021.661403. eCollection 2021.
The infrapatellar fat pad (IFP) is actively involved in knee osteoarthritis (OA). However, a proper description of which developmental modifications occur in the IFP along with age and in absence of joint pathological conditions, is required to adequately describe its actual contribution in OA pathophysiology. Here, two IFP sources were compared: (a) IFP from healthy young patients undergoing anterior-cruciate ligament (ACL) reconstruction for ACL rupture ( = 24); (b) IFP from elderly cadaver donors ( = 23). After histopathological score assignment to confirm the absence of inflammatory features (i.e., inflammatory infiltrate and increased vascularity), the adipocytes morphology was determined; moreover, extracellular matrix proteins were studied through histology and Second Harmonic Generation approach, to determine collagens content and orientation by Fast Fourier Transform and OrientationJ. The two groups were matched for body mass index. No inflammatory signs were observed, while higher area, perimeter, and equivalent diameter and volume were detected for the adipocytes in the elderly group. Collagen III displayed higher values in the young group and a lower total collagen deposition with aging was identified. However, collagen I/III ratio and the global architecture of the samples were not affected. A higher content in elastic fibers was observed around the adipocytes for the ACL-IFPs and in the septa cadaver donor-IFPs, respectively. Age affects the characteristics of the IFP tissue also in absence of a pathological condition. Variable mechanical stimulation, depending on age-related different mobility, could be speculated to exert a role in tissue remodeling.
髌下脂肪垫（IFP）积极参与膝关节骨关节炎（OA）。然而，需要对IFP在无关节病理状况下随年龄发生的发育变化进行恰当描述，以便充分说明其在OA病理生理学中的实际作用。在此，比较了两种IFP来源：（a）因前交叉韧带（ACL）断裂而接受ACL重建的健康年轻患者的IFP（n = 24）；（b）老年尸体供体的IFP（n = 23）。在进行组织病理学评分以确认无炎症特征（即炎症浸润和血管增多）后，确定脂肪细胞形态；此外，通过组织学和二次谐波产生方法研究细胞外基质蛋白，以通过快速傅里叶变换和OrientationJ确定胶原蛋白的含量和取向。两组在体重指数方面相匹配。未观察到炎症迹象，而老年组脂肪细胞的面积、周长、等效直径和体积更高。年轻组中III型胶原蛋白的值更高，且随着年龄增长总胶原蛋白沉积降低。然而，I/III型胶原蛋白比率和样本的整体结构未受影响。分别在ACL - IFP的脂肪细胞周围和尸体供体IFP的间隔中观察到弹性纤维含量更高。在无病理状况时，年龄也会影响IFP组织特性。可以推测，取决于与年龄相关的不同活动度的可变机械刺激在组织重塑中发挥作用。
