Temporal production of nitric oxide and Prostaglandin E2 in media of explant cultures of equine synovial membrane and articular cartilage

Abstract

SummaryThe local mediators nitric oxide (NO) and prostaglandin E, (PGE ) play a role in the cascade of extracellular matrix breakdown in articular cartilage. In the present study the spontaneous production of NO and PGE, in explant cultures of equine synovial membrane and articular cartilage and their concentration over tjme n culture was investigated and correlated. Synovial membrane and articular cartilage was harvested from metacarpophalangeal jonts of 33 horses durlng arthroscopic surgery (n=4) or after being slaughtered/euthanised for reasons other than infectious or metabolic dlsease (n=29). Trssues were cultured as explant cuJtures in the presence of 4 ml Ham's F 12 medium, supplemented with streptomycin (100 pg/ml) and penicillin (100 U/ml) and incubated in a 5% CO2 and water saturated atmosphere for 8 days. Re sults showed that generally equine synovial membrane produced less NO than articular cartilage explant cultures with comparable wet weights/ml of media, but significantly more PGE, (P<0.05). The concentrations of both mediators were relatively stable over the first 4 days of culture, at least in the group of 25 mg wet wdghvml of media. In this group, there was a weak tendency noticed for NO to decrease, and PGE, to increase over time with day 4 being the intersection for both. Tissue cultures of articular cartilage with 12.5 mg wet weight/ml of culture media produced less reliable results, especially with NO measurements, which was thought to be associated with the sensitivity of the assay. lt is recommended to collect conditioned media for the measurements of NO and PGE, within the first 4 days of explant culture, since atter this time period culture effects may mask the results at least for NO measurements. Both mediators may be factors that play an impor tant role in the local med ation of ioint inflammations. Keywords:nitric oxide, prostaglandin Er, synovial membrane, articular cartilage, equine Die zeitlich bedingte Produktion von Stickoxid (NO) und Prostaglandin E, (PGEr) in Medium von Gewebekultur€n aus Synovialmembran und GelenkknorDel von PferdenDie lokalen Mediatoren, Stickoxid (nitric oxide = NO) und Prostaglandin E, (PGEr) spielen eine Rolle in der Kaskade des Abbaus der extrazellulären lvlatrix von Knorpel und Knochen. In der vorliegenden Studie wurde die spontane Produktion und Konzentration von NO und PGE2 in Gewebekulturen aus Synovialmembran und Gelenkknorpel von Pferden über eine Zeit von B Tagen untersucht und korreliert. Bei 33 Pferden wurde während der Arthroskopie des Gelenkes {n=4) oder zum Zeitpunkt der Schlachtung (n=29) Synovialmembran und Gelenkknorpel aus dem Fesselgelenk entnommen. Das Gewebe wurde in der Gewebekultur ('12.5 mg/ml Medium und 25 mg/ml Medium) n Ham's F-1 2 Medi um, angereichert mit Streptomycin (100 pg/ml) und Penicillin (100 U/ml), unter Standardbedingungen von 5% CO, und mit Wasser gesättig-ter Atmosphäre für B Tage inkubiert. Es wurde gezeigt, dass allgemein die Synovialmembran Gewebekulturen deutlich weniger NO produzierten als die Gelenkknorpel Gew...

Fibrous Tissue of Subchondral Cystic Lesions in Horses Produce Local Mediators and Neutral Metalloproteinases and Cause Bone Resorption in Vitro

“…Interestingly, in experiment 2 in which SCL tissue was compared with synovial membrane and articular cartilage of equine joints with chip fractures, collagenolytic and gelatinolytic activities but not caseinolytic activity in SCL were very low. It may be that the high concentrations of NO and PGE2 in SCL inhibited the production of collagenase and gelatinase, confirming similar findings in our earlier study in which negative correlations between these local mediators and the production of NMPs were reported 21,24 …”

“…Concentrations of NO, PGE2, and NMPs were often higher in SCL compared with joints with severe OA. This corresponded with our earlier findings in which joints affected with moderate OA generally produced higher concentrations of local mediators and matrix‐degrading enzymes compared with normal joints or joints with severe OA 24 . We speculated then that tissue from severe OA joints had lower cell numbers and viability.…”

“…To remove all blood coagula, tissues were washed several times in Gey's balanced salt solution (GBBS; GIBCO, Life Technology, Basel, Switzerland). Thereafter, tissue samples were cultured as previously described 21–23 . Briefly, tissue specimens were trimmed, weighed, and washed in GBBS.…”

“…Results were compared with results obtained from explant cell cultures of equine synovial membrane and articular cartilage from metacarpophalangeal joints of horses with normal joints (n = 7), moderate OA (7), and severe OA (10), as published previously 24 . Classification of OA was based on observation of the extent of articular cartilage damage.…”

In Vitro Studies of a Photo‐oxidized Bovine Articular Cartilage

“…These authors found that low concentrations of NO enhance PGE 2 , whereas high concentrations inhibit its synthesis. The same correlations between NO and PGE 2 concentration were found over 4 days in media of articular cartilage explant and synovial membrane cultures in other studies (von Rechenberg et al., 1998). In addition, in the same study a tendency for negative correlation's between NO and NMPs, and PGE 2 and NMPs was demonstrated.…”