scholarly journals Osteoarthritic Infrapatellar Fat Pad Aggravates Cartilage Degradation via Activation of p38MAPK and ERK1/2 Pathways

2020 ◽  
Author(s):  
Zuoqing Zhou ◽  
Su'an Tang ◽  
Xiaoyu Nie ◽  
Yiqun Zhang ◽  
Delong Li ◽  
...  

Abstract Background: Although existing studies have suggested the involvement of the infrapatellar fat pad (IPFP) during the development of knee osteoarthritis (OA), the role of IPFP is still controversial. This study aimed to investigate the biochemical effects of osteoarthritic IPFP on cartilage and the underlying mechanisms.Methods: Human IPFP and articular cartilage were collected from end-stage OA patients during total knee arthroplasty. IPFP derived fat-conditioned medium (FCM) was used to stimulate human primary chondrocytes and cartilage explants. CCK8 was used to detect the viability of human chondrocyte. qRT-PCR and western blotting was performed to evaluate the balance of extracellular matrix (ECM) catabolism and anabolism in human chondrocytes with FCM stimulation. Functional effect of osteoarthritic IPFP was also demonstrated in human articular cartilage by ex vivo assay. Activation of relative pathways and its effects on chondrocytes were assessed through immunoblotting and inhibition experiments, respectively. Neutralization test was performed to identify the main factors and their associated pathways responsible for the effects of IPFP. Results: Osteoarthritic IPFP-derived FCM significantly induced extracellular matrix (ECM) degradation in both human primary chondrocytes and cartilage explants. Several pathways, such as NF-κB, mTORC1, p38MAPK, JNK, and ERK1/2 signaling were significantly activated in human chondrocytes with osteoarthritic IPFP-derived FCM stimulation. Interestingly, inhibition of p38MAPK and ERK1/2 signaling pathway could alleviate the detrimental effects of FCM on chondrocytes while inhibition of other signaling pathways had no similar results. In addition, IL-1β and TNF-α instead of IL-6 in osteoarthritic IPFP-derived FCM played a key role in cartilage degradation via activating p38MAPK rather than ERK1/2 signaling pathway.Conclusions: Osteoarthritic IPFP induces the degradation and inflammation of cartilage via activation of p38MAPK and ERK1/2 pathways, in which IL-1β and TNF-α act as the key factors. Our study suggests that modulating the effects of IPFP on cartilage may be a promising strategy for knee OA intervention.

Author(s):  
Stephen Cornish ◽  
Jason Peeler

Background: Knee osteoarthritis (OA) has been linked to a chronic low-grade inflammatory response and altered metabolic activity of articular cartilage. Objective: The purpose of this investigation was to evaluate the effectiveness of a 12-week (3 times/week) lower body positive pressure (LBPP) treadmill walking regime on knee pain and systemic biomarkers of inflammation and cartilage degradation. Methods: Sixteen overweight (BMI > 25 kg/m2) knee OA patients were randomized to a LBPP treadmill walking exercise group (N = 7) or non-exercise control group (N = 9). Baseline and 12-week follow-up assessments evaluated the following dependent variables: acute knee pain during full weight bearing treadmill walking; inflammatory biomarkers (C-reactive protein, interleukin-1β, interleukin-6, s100A8/A9, and tumor necrosis factor-α), and catabolic metabolism of articular cartilage (sCOMP). Results: Knee pain at baseline and follow-up remained unchanged for the non-exercise control group (P > 0.05). However, knee pain for the LBPP exercise group was significantly decreased at follow-up (P ≤ 0.05). No differences in the biomarkers of inflammation and cartilage degradation were observed for between and within group comparisons (all P > 0.05). Conclusions: Data suggested that the LBPP supported walking regime could be effectively used to promote regular weight bearing exercise without exacerbation of knee joint pain and did not increase levels of systemic inflammation or catabolic activity of articular cartilage in overweight knee OA patients. This pilot investigation offers important insight regarding the potential role that the LBPP technology could play in facilitating investigations examining the disease modifying effect of exercise on knee OA pathogenesis.


Author(s):  
Roman M. Natoli ◽  
Kyriacos A. Athanasiou

Impact loading of articular cartilage leads to post-traumatic osteoarthritis (OA) through its effects on the cells and extracellular matrix (ECM) of the tissue. Studies have shown the level of impact or injurious compression correlates with increased cell death, degradation of the ECM, and detrimental changes in biomechanical properties [1]. Recently, several bioactive agents, such as P188 and IGF-I, have shown promising results by reducing cell death following injurious compression of cartilage explants [2, 3].


2014 ◽  
Vol 111 (8) ◽  
pp. 1686-1698 ◽  
Author(s):  
Tariq Mesallati ◽  
Conor T. Buckley ◽  
Daniel J. Kelly

Author(s):  
Zuoqing Zhou ◽  
Su’an Tang ◽  
Xiaoyu Nie ◽  
Yiqun Zhang ◽  
Delong Li ◽  
...  

2019 ◽  
Vol 844 ◽  
pp. 49-55 ◽  
Author(s):  
Zhirong Wang ◽  
Menglei Xu ◽  
Jiaxiang Bai ◽  
Gaoran Ge ◽  
Xiaobin Guo ◽  
...  

F1000Research ◽  
2013 ◽  
Vol 2 ◽  
pp. 147 ◽  
Author(s):  
Abigail L Clutterbuck ◽  
David Allaway ◽  
Pat Harris ◽  
Ali Mobasheri

Objective: Curcumin (diferuloylmethane) is a phytochemical with potent anti-inflammatory and anti-oxidant properties, and has therapeutic potential for the treatment of a range of inflammatory diseases, including osteoarthritis (OA). The aim of this study was to determine whether non-toxic concentrations of curcumin can reduce interleukin-1beta (IL-1β)-stimulated inflammation and catabolism in an explant model of cartilage inflammation.Methods: Articular cartilage explants and primary chondrocytes were obtained from equine metacarpophalangeal joints. Curcumin was added to monolayer cultured primary chondrocytes and cartilage explants in concentrations ranging from 3μM-100μM. Prostaglandin E2 (PGE2) and matrix metalloproteinase (MMP)-3 release into the secretome of IL-1β-stimulated explants was measured using a competitive ELISA and western blotting respectively. Proteoglycan (PG) release in the secretome was measured using the 1,9-dimethylmethylene blue (DMMB) assay. Cytotoxicity was assessed with a live/dead assay in monolayer cultures after 24 hours, 48 hours and five days, and in explants after five days.Results: Curcumin induced chondrocyte death in primary cultures (50μM p<0.001 and 100μM p<0.001) after 24 hours. After 48 hours and five days, curcumin (≥25μM) significantly increased cell death (p<0.001 both time points). In explants, curcumin toxicity was not observed at concentrations up to and including 25μM after five days. Curcumin (≥3μM) significantly reduced IL-1β-stimulated PG (p<0.05) and PGE2 release (p<0.001) from explants, whilst curcumin (≥12μM) significantly reduced MMP-3 release (p<0.01).Conclusion: Non-cytotoxic concentrations of curcumin exert anti-catabolic and anti-inflammatory effects in cartilage explants.


2019 ◽  
Vol 85 ◽  
pp. 75-83 ◽  
Author(s):  
Yong Mao ◽  
Travis Block ◽  
Anya Singh-Varma ◽  
Anne Sheldrake ◽  
Rachel Leeth ◽  
...  

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