Functional significance of nerve growth factor and its receptor (TrkA) in inflammatory arthritis

Table 1 Unstimulated fibroblast-like synoviocytes of patients with psoriatic arthritis or rheumatoid arthritis express higher levels of nerve growth factor and TrkA

		FACS analyses, percentage of cells
Cells	NGF, pg/mL	NGF⁺	TrkA⁺	p75⁺
Unstimulated FLSs (meniscal injury n = 4)	30 ± 5	4.5 ± 0.3	1.33 ± 0.4	0.5 ± 0.05
FLSs + IL-1β (meniscal injury)	110 ± 28^a	12.4 ± 2^a	16.5 ± 5^a	0.4 ± 0.2
FLSs + TNF-a (meniscal injury)	129 ± 23^a	6.3 ± 4^a	11.5 ± 5^a	0.71 ± 0.4
FLSs from patients with PsA (n = 3)	105 ± 15^a	17 ± 4^a	10 ± 3^a	1.0 ± 0.4
FLSs from patients with RA (n = 4)	65 ± 4^b	8 ± 0.4^b	5.5 ± 0.4^b	0.5 ± 0.4
FLSs from patients with OA (n = 4)	34 ± 2	3.9 ± 0.2	0.9 ± 0.2	0.7 ± 0.2

Third-passage fibroblast-like synoviocytes (FLSs) (5,000 cells in 200 μL of Dulbecco's modified Eagle's medium [DMEM] complete medium) in 96-well plates were cultured for 6 days. Unstimulated cells were cultured in DMEM only, and stimulated cells were cultured in DMEM with cytokines tumor necrosis factor-alpha (TNF-α) (1 ng/mL) and interleukin-1-beta (IL-1β) (1 ng/mL). Data are expressed as mean ± standard deviation. Nerve growth factor (NGF), TrkA, and p75 data of unstimulated FLSs were compared with NGF, TrkA, and p75 data of FLSs of other groups mentioned in the table. ^a/bSignificantly different from unstimulated cells (^aP < 0.001, ^bP < 0.05 Student t test). FACS, fluorescence-activated cell sorting; OA, osteoarthritis; PsA, psoriatic arthritis; RA, rheumatoid arthritis.

ISSN: 1478-6362