Gene expression, protein profiling, and chemotactic activity of infrapatellar fat pad mesenchymal stem cells in pathologies of the knee joint

Abstract

The infrapatellar fat pad (IPFP) is a periarticular adipose knee tissue. This tissue contains a large number of mesenchymal stem cells (MSCs). In the present work, we wanted to study the IPFP MSCs and their relationship and differences in two groups, anterior cruciate ligament (ACL) ruptures knees and ostheoarthrosis (OA). The IPFP of 42 patients with OA or ACL rupture were analyzed. Isolation, primary culture, and a genetic and proteomic study of MSCs from IPFP were performed. Gene expression of IL‐6, tumor necrosis factor (TNF), IL‐8, HSPA1A (Hsp70), CXCL10, RANTES, MMP1, MMP3, TIMP1, and BMP7 was analyzed by real‐time quantitative polymerase chain reaction (RT‐qPCR). We analyzed MSCs from from 12 diferents patients in two cellular pools (6 from AO disease and 6 from ALC rupture to form two cell pool), for the iTRAQ Proteomic Assay. The conditional media were used in quantitative analysis of MSC soluble factors by Luminex and for de migration assay. A higher gene expression of IL‐6, TNF, CXCL10, RANTES, and MMP1 and OPG in MSCs from OA versus ACL (p < 0.05) was observed. Conversely HSPA1A, TIMP1, and RANKL showed a significant lower expression in OA‐MSCs (p < 0.05). In the secretome analysis, adipsin and visfantin levels in the supernatants from OA‐MSCs were lower (p < 0.05) respect to ACL‐MSCs. Also, the monocytic cells migrated two‐folds in the presence of conditioned media from OA‐MSCs patients versus patients with ACL‐MSC. The infrapatellar pad should be considered as an adipose tissue capable of producing and excreting inflammatory mediators directly in the knee joint, influencing the development and progression of knee joint pathologies.

COMP in the Infrapatellar Fat Pad—Results of a Prospective Histological, Immunohistological, and Biochemical Case–Control Study

“…17,25 A higher gene expression of IL-6 was found in mesenchymal stem cells from the fad pad of OA patients compared with a control group of patients with an ACL rupture. 41 Favero et al 25 detected increased IL-6 protein levels in OA IPFPs compared with control IPFPs from cadavers with no signs of knee OA. We found no differences in the staining intensity scores of IL-1β and IL-6 between OA and control samples from the young with a rupture of the ACL.…”

“…Recent studies have shown that also the IPFP secretes proinflammatory cytokines and may modulate the inflammatory processes contributing to the pathomechanism of knee OA . A higher gene expression of IL‐6 was found in mesenchymal stem cells from the fad pad of OA patients compared with a control group of patients with an ACL rupture . Favero et al detected increased IL‐6 protein levels in OA IPFPs compared with control IPFPs from cadavers with no signs of knee OA.…”

“…To our knowledge, there is no study which compares the IPFP extracellular matrix from patients with high‐grade OA with a control group of IPFPs from young and non‐osteoarthritic patients. There is one recent study which analyzed IPFP derived mesenchymal stem cells from old patients with high‐grade OA and from young patients with an anterior cruciate ligament (ACL) rupture and no signs of OA. Here, a proteomic study of the mesenchymal stem cells from the IPFP was done.…”

Culture Time Needed to Scale up Infrapatellar Fat Pad Derived Stem Cells for Cartilage Regeneration: A Systematic Review

“…All 12 included articles were controlled single-institution studies (Table 2). Of the 12 isolated studies, 11 were retrospective [23][24][25][26][27][28][29][30][31][32][33] and one was a prospective cohort study [34]. There was a total of 228 patient IFPs assessed in the 12 studies.…”

“…The patient ages ranged between 17 and 89. From the six studies indicating gender [23][24][25]27,31,34], 77 (62%) patients were female and 48 (38%) were male.…”