Table 2.

Comparative proteomics of human AKU chondrocytes. Proteins whose synthesis was altered in AKU chondrocytes versus controls.

Spot	ANa	Gene	Protein	Biological processesb	AKU chondrocytes/ctrc
GRP75	P38646	HSPA9	Stress-70 protein, heat shock 70 kDa protein 9 or 75 kDa glucose-regulated protein	Implicated in the control of cell proliferation and cellular aging. May also act as a chaperone. Anti-apoptotic functions	− 2.1
PARK7	Q99497	PARK7	Protein DJ-1	May function as a redox-sensitive chaperone and as a sensor for oxidative stress. Prevents aggregation of SNCA.	− 5.5
PDIA1	P07237	P4HB	Protein disulfide-isomerase	Catalyzes the formation, breakage and rearrangement of disulfide bonds. At high concentrations, functions as a chaperone that inhibits aggregation of misfolded proteins. At low concentrations, facilitates aggregation (anti-chaperone activity).	− 2.3
GELS	P06396	GSN	Gelsolin	Binds to actin and to fibronectin. Calcium-regulated, actin-modulating protein that binds to the plus (or barbed) ends of actin monomers or filaments, preventing monomer exchange (end-blocking or capping). It can promote the assembly of monomers into filaments (nucleation) as well as sever filaments already formed. Defects in GSN are the cause of amyloidosis type 5 (AMYL5) [MIM: 105120], also known as familial amyloidosis Finnish type.	− 2.0
TAGL	Q01995	TAGLN	Transgelin	Actin cross-linking/gelling protein. Involved in calcium interactions and contractile properties of the cell that may contribute to replicative senescence.	+ 17.0
ENPL	P14625	HSP90B1	Endoplasmin, 94 kDa glucose-regulated protein, GRP-94, Heat shock protein 90 kDa beta member 1	Molecular chaperone that functions in the processing and transport of secreted proteins. Functions in endoplasmic reticulum associated degradation (ERAD). Has ATPase activity. Plays a role in protein folding and transport, has anti-apoptotic functions.	− 4.8
HSP74	P34932	HSPA4	Heat shock 70 kDa protein 4	Stress response, plays a role in the unfolded protein response.	− 5.4
CATD	P07339	CTSD	Cathepsin D	Acid protease active in intracellular protein breakdown. Involved in the pathogenesis of several diseases, AA amyloidosis included.	− 3.8

^aAN: accession number.

^bProtein biological processes retrieved by UniProt knowledgebase (http://www.uniprot.org/).

^cFold-change in protein % relative abundance (as average values in case of multiple spots); (+) over-expressed proteins, (−) under-expressed protein according to the ratio calculated between AKU and control (ctr) cells.