Dopamine delays articular cartilage degradation in osteoarthritis by negative regulation of the NF-kappa B and JAK2/STAT3 signaling pathways
BIOMEDICINE & PHARMACOTHERAPY
Authors: Lu, Wei; Ding, Zhenfei; Liu, Fuen; Shan, Wenshan; Cheng, Chao; Xu, Jiegou; He, Wei; Huang, Wei; Ma, Junting; Yin, Zongsheng
Abstract
Background: The progressive loss of cartilage matrix and the breakdown of articular cartilage induced by inflammation play an essential role in osteoarthritis (OA) pathogenesis. Dopamine (DA) is a critical neurotransmitter that is not only involved in controlling exercise, emotion, cognition and neuroendocrine activity but also has anti-inflammatory effects. This study aimed to investigate the effects of DA on OA in vitro and in vivo. Methods: OA progression was evaluated in a mouse model with surgically induced destabilization of the medial meniscus. Cartilage degradation and OA were analyzed using Safranin O/Fast Green staining. Additionally, qRT-PCR and Western blotting were applied to detect catabolic and anabolic factors involved in cartilage degeneration and underlying mechanisms in OA chondrocytes treated with Interleukin-1 beta. Results: In vitro, DA treatment inhibited the production of inducible nitric oxide synthase, cyclooxygenase-2, matrix metalloproteinase (MMP)-1, MMP-3, and MMP-13, while increasing type II collagen and glycosaminoglycan content. Mechanistically, DA reversed IL-1 beta-treated nuclear factor-kappa B activation and JAK2/STAT3 phosphorylation. Furthermore, DA suppressed the degradation of cartilage matrix and reduced Osteoarthritis Research Society International scores in the surgically induced OA models. Conclusion: DA may be a novel therapeutic agent for OA treatment.
Alterations in the chondrocyte surfaceome in response to pro-inflammatory cytokines
BMC MOLECULAR AND CELL BIOLOGY
Authors: Jeremiasse, Bernadette; Matta, Csaba; Fellows, Christopher R.; Boocock, David J.; Smith, Julia R.; Liddell, Susan; Lafeber, Floris; van Spil, Willem E.; Mobasheri, Ali
Abstract
Background Chondrocytes are exposed to an inflammatory micro-environment in the extracellular matrix (ECM) of articular cartilage in joint diseases such as osteoarthritis (OA) and rheumatoid arthritis (RA). In OA, degenerative changes and low-grade inflammation within the joint transform the behaviour and metabolism of chondrocytes, disturb the balance between ECM synthesis and degradation, and alter the osmolality and ionic composition of the micro-environment. We hypothesize that chondrocytes adjust their physiology to the inflammatory microenvironment by modulating the expression of cell surface proteins, collectively referred to as the 'surfaceome'. Therefore, the aim of this study was to characterize the surfaceome of primary equine chondrocytes isolated from healthy joints following exposure to the pro-inflammatory cytokines interleukin-1-beta (IL-1 beta) and tumour necrosis factor-alpha (TNF-alpha). We employed combined methodology that we recently developed for investigating the surfaceome in stem cells. Membrane proteins were isolated using an aminooxy-biotinylation technique and analysed by mass spectrometry using high throughput shotgun proteomics. Selected proteins were validated by western blotting. Results Amongst the 431 unique cell surface proteins identified, a high percentage of low-abundance proteins, such as ion channels, receptors and transporter molecules were detected. Data are available via ProteomeXchange with identifier PXD014773. A high number of proteins exhibited different expression patterns following chondrocyte stimulation with pro-inflammatory cytokines. Low density lipoprotein related protein 1 (LPR-1), thrombospondin-1 (TSP-1), voltage dependent anion channel (VDAC) 1-2 and annexin A1 were considered to be of special interest and were analysed further by western blotting. Conclusions Our results provide, for the first time, a repository for proteomic data on differentially expressed low-abundance membrane proteins on the surface of chondrocytes in response to pro-inflammatory stimuli.