Enhanced expression of tissue inhibitor of metalloproteinases (TIMP) mRNAs in human dermal fibroblasts treated with culture supernatants (a) and whole bacterial cell lysates (b) obtained from Sar A-/- and Sar A-/-Agr-/- mutants of Staphylococcus aureus and isogenic parent strain. Culture supernatants and cell lysates obtained from an S. aureus strain isolated from synovial fluid of a septic arthritis patient (obtained from American Type Culture Collection, Manassas, VA, USA), a clinical isolate (U1), its Sar A mutant (U929), and Agr/Sar A double-loci-deleted mutant (U930) (strains obtained from M. Smeltzer) were used. Equal amounts of total protein from all samples were added to confluent monolayers of fibroblast cultures. Total RNA was harvested from the cells 12 hours after exposure to the supernatants. The levels of TIMP-1, -2, and -3 mRNAs were estimated by real-time SYBR green reverse transcription-polymerase chain reaction. The values plotted represent the ratios of the threshold cycle values of TIMPs to that of the housekeeping gene GAPDH (glyceraldehyde phosphate dehydrogenase). Agr, accessory gene regulator; Sar, staphylococcal accessory regulator; SUP, culture supernatant.