Time-dependent proteomic and genomic alterations in Toll-like receptor-4-activated human chondrocytes: increased expression of lamin A/C and annexins

Abstract

Activation of Toll-like receptor-4 (TLR-4) in articular chondrocytes increases the catabolic compartment and leads to matrix degradation during the development of osteoarthritis. In this study, we determined the proteomic and genomic alterations in human chondrocytes during lipopolysaccharide (LPS)-induced inflammation to elucidate the underlying mechanisms and consequences of TLR-4 activation. Human chondrocytes were cultured with LPS for 12, 24, and 36 h to induce TLR-4 activation. The TLR-4-induced inflammatory response was confirmed by real-time PCR analysis of increased interleukin-1 beta (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor alpha (TNF-α) expression levels. In TLR-4-activated chondrocytes, proteomic changes were determined by two-dimensional electrophoresis and matrix-assisted laser desorption/ionization-mass spectroscopy analysis, and genomic changes were determined by microarray and gene ontology analyses. Proteomics analysis identified 26 proteins with significantly altered expression levels; these proteins were related to the cytoskeleton and oxidative stress responses. Gene ontology analysis indicated that LPS treatment altered specific functional pathways including ‘chemotaxis’, ‘hematopoietic organ development’, ‘positive regulation of cell proliferation’, and ‘regulation of cytokine biosynthetic process’. Nine of the 26 identified proteins displayed the same increased expression patterns in both proteomics and genomics analyses. Western blot analysis confirmed the LPS-induced increases in expression levels of lamin A/C and annexins 4/5/6. In conclusion, this study identified the time-dependent genomic, proteomic, and functional pathway alterations that occur in chondrocytes during LPS-induced TLR-4 activation. These results provide valuable new insights into the underlying mechanisms that control the development and progression of osteoarthritis.

β Boswellic Acid Blocks Articular Innate Immune Responses: An In Silico and In Vitro Approach to Traditional Medicine

“…Specifically, MAPK p38/NFκB, TNF, IFNαβ, ROS, and NLRP3 downstream pathways were found enriched whereas ECM anabolic pathways were found depleted in the proteome of stimulated chondrocytes. These proteomic changes were consistent with increased inflammatory and catabolic OA-like phenotype [107][108][109]. Likewise, the enrichment in ROS-related pathways including NO synthesis was in concordance with OA worsening associated with oxidative stress [110,111].…”

ANXA9 facilitates S100A4 and promotes breast cancer progression through modulating STAT3 pathway

“…ANXA9 belongs to the annexin (ANX) family, and Annexin proteins are structurally characterized by their core domains, which consist of a series of four repeated annexin sequences, each containing a calcium-binding motif that mediates reversible calciumdependent binding with negatively charged phospholipids [16], such as phosphatidylserine, phosphatidylglycerol, and phosphatidylinositol [17]. Functionally, annexin, as a membrane binding protein regulated by calcium [18,19], not only participates in cell membrane formation [20], regulates transmembrane transport [21] and calcium ion aggregation inside and outside the membrane [22], but also regulates physiological functions such as cell cycle and apoptosis [23,24]. There are few studies reports on ANXA9, with most studies focusing on digestive system tumors [4,25].…”

Establishing SW1353 Chondrocytes as a Cellular Model of Chondrolysis

“…As suggested earlier, serum deprivation may enhance the IL-1β signalling in SW1353 cells and greatly upregulated the TNF-α level, despite being at lower concentration. In terms of morphology, the IL-1β- or lipopolysaccharide-stimulated primary human articular chondrocytes displayed no noticeable changes [ 81 ] or changed to a rounded shape with smaller cell size [ 75 ]. In both cases, no cell death features were observed.…”