gms | German Medical Science

Deutscher Kongress für Orthopädie und Unfallchirurgie (DKOU 2019)

22. - 25.10.2019, Berlin

Understanding the fat pad's role in the knee osteoarthritis: The influence of infrapatellar fat pad on cytokine expression in chondrocytes

Meeting Abstract

  • presenting/speaker Michal Jagielski - Charite - Universitätsmedizin Berlin, CBF, Orthopädie, Unfall- und Wiederherstellungschirurgie, Berlin, Germany
  • Ewa Wisniewska - Charite - Universitätsmedizin Berlin, CBF, Orthopädie, Unfall- und Wiederherstellungschirurgie, Berlin, Germany
  • Stefan Stich - Charite - Universitätsmedizin Berlin, CBF, Orthopädie, Unfall- und Wiederherstellungschirurgie, Berlin, Germany
  • Benjamin Kohl - Charite - Universitätsmedizin Berlin, CBF, Orthopädie, Unfall- und Wiederherstellungschirurgie, Berlin, Germany
  • Wolfgang Ertel - Charite - Universitätsmedizin Berlin, CBF, Orthopädie, Unfall- und Wiederherstellungschirurgie, Berlin, Germany

Deutscher Kongress für Orthopädie und Unfallchirurgie (DKOU 2019). Berlin, 22.-25.10.2019. Düsseldorf: German Medical Science GMS Publishing House; 2019. DocAB57-1209

doi: 10.3205/19dkou542, urn:nbn:de:0183-19dkou5424

Veröffentlicht: 22. Oktober 2019

© 2019 Jagielski et al.
Dieser Artikel ist ein Open-Access-Artikel und steht unter den Lizenzbedingungen der Creative Commons Attribution 4.0 License (Namensnennung). Lizenz-Angaben siehe http://creativecommons.org/licenses/by/4.0/.


Gliederung

Text

Objectives: Osteoarthritis affects most frequently the knee joint. The progression of cartilage degeneration is not only caused by increased weight bearing, but also by inflammation. Chondrocytes produce inflammatory mediators such as tumor necrosis factor a (TNFa) and degrading enzymes such as matrix metalloproteinases MMPs. Infrapatellar fat pad (FP) lies intraarticularly, covered by the synovial membrane under the patella. The difference in gene expression between FP and other fatty tissue suggests its autonomous function. Our aim is to identify the pattern of cytokine and cartilage markers expression in chondrocytes under the influence of FP in order to understand its role in the Osteoarthritis progression.

Methods: In our clinic, FP and cartilage are collected from patients undergoing total knee arthroplasty. Furthermore, we collect FP samples from young patients undergoing knee arthroscopy. Vitality of FP is analysed with immunocytochemistry staining (IHC). The cartilage is divided into weight bearing (degenerated) and non-weight bearing area. Chondrocytes are being isolated separately from two different areas of the cartilage and set in a transwell system as degenerated (OA) and non-degenerated (CO) cells together with either arthritic or young FP. Expression of cartilage associated genes type II collagen and aggrecan; proinflammatory cytokines TNFa, interleukin(IL)-6; catabolic enzymes matrix metalloproteinases -1,-3,-9,-13; anti-inflammatory cytokine IL-10 in chondrocytes and FP is analysed by qRT-PCR at day 0 and day 2.

Results and conclusion: FP were vital up to 7 days after resection. There was no significant difference in gene expression of TNFa and MMP-13 between OA and CO at day 0. OA and CO expressed significantly (p<0.05, n=4) less TNFa in co-culture with FP after 2 days. TNFa expression was significantly (p<0.05, n=4) upregulated in OA after 2 days of culture. Moreover, after 2 days there was no significant difference in the gene expression of MMP-13 between OA and CO. Expression of MMP-13 was higher in co-culture in comparison to day 0 control samples, yet there was no significant difference in comparison to day 2 controls.

FP could significantly reduce the expression of TNFa without inducing the MMP-13 in chondrocytes. Next, (i) we will perform the analysis of gene expression of further cytokines, cartilage markers and catabolic enzymes in chondrocytes and FP; (ii) we will also begin with transwell cultures with young FP; (iii) differences in histological morphology, cell distribution and secretory functions of the FP will be performed using ELISA and IHC. Our preliminary work and first results implicate a chondroprotective role of the FP. Thus, common arthroscopic partial FP resection during e.g. anterior cruciate ligament reconstruction should be re-evaluated. We believe that our study will not only help us to better understand the role of FP in Osteoarthritis but could also lead to the development of new diagnostic and therapy strategies.