Study On The Effects Of Low-intensity Pulsed Ultrasound And Pioglitazone On Rabbit Osteoarthritis Chondrocytes

Part I Effect of different concentrations of pioglitazone on LPS-induced rabbit osteoarthritisObjective To investigate the effect of different concentrations of pioglitazone on LPS-induced rabbit osteoarthritis(OA).Methods 18 healthy adult male New Zealand white rabbits were randomly divided into 6 groups: normal group,LPS group,1?M group(LPS+1?M pioglitazone),10?M group(LPS+10?M pioglitazone),and 50?M group(LPS+50?M pioglitazone),100?M group(LPS+100?M pioglitazone),3 rabbits per group.Six groups of normal rabbit knee chondrocytes were extracted,and chondrocytes in LPS group and different concentrations of pioglitazone group were cultured in 2?g/ml LPS medium for 4 h.Thereafter,chondrocytes in each concentration of pioglitazone group were continuously cultured in a medium containing 1?M,10?M,50?M,and 100?M pioglitazone.Seven days later,the levels of interleukin-4(IL-4),tumor necrosis factor-?(TNF-?),and leptin(LEP)in knee cartilage cells were measured by ELISA.Results Compared with the normal group,the expression of IL-4 in 100?M group was higher(P < 0.05),and there was no significant difference between the other groups.Compared with the 1?M and 10?M groups,the expression of TNF-? and LEP in 50?M and 100?M groups decreased more significantly.Conclusion Pioglitazone can stimulate the expression of IL-4 in OA chondrocytes and play a protective role in cartilage.At the same time,pioglitazone also can inhibit the expression of TNF-? and LEP in OA chondrocytes and reduce inflammation.Part II Effects of low-intensity pulsed ultrasound and pioglitazone in rabbit osteoarthritisObjective To investigate any protective effect of low intensity pulsed ultrasound(LIPUS)and pioglitazone on osteoarthritis chondrocytes through the pathway from peroxisome proliferator-activated receptors ?(PPAR?)to nuclear factor kappa B(NF-?B)to inducible nitric oxide synthase(i NOS).Methods Normal chondrocytes of 24 healthy adult New Zealand white rabbits were extracted and divided into normal group,LPS group,a LIPUS group(LPS + LIPUS)and a pioglitazone group(LPS + pioglitazone),each of 6 using a random number table.Each group was give the intervention theirs names implies.The levels of tumor necrosis factor-?(TNF-?),leptin(LEP)and nitric oxide(NO)in the chondrocytes were detected using enzyme-linked immune sorbent assays.The expression of type ? collagen(COL2)in the chondrocytes of each group was detected by immunocytochemistry and fluorescent staining.The m RNA and protein expressions of PPAR?,NF-?B and i NOS in chondrocytes were detected using reverse transcription polymerase chain reactions and western blotting respectively.Results Compared with the LPS group,the average level of TNF-?,LEP and NO in the LIPUS and pioglitazone groups was significantly lower(P<0.05),with the levels in the pioglitazone group significantly lower than in LIPUS group.Compared with the LPS group,COL2 expression in the LIPUS group was significantly greater(P<0.05).The m RNA and protein expressions of PPAR? in the chondrocytes in the LIPUS and pioglitazone groups were significantly higher than those in the LPS group.Compared with the LPS group,the m RNA and protein expressions of NF-?B and i NOS in the pioglitazone and LIPUS group was significantly lower(P<0.05),with the pioglitazone group's levels significantly below those of the LIPUS group.Conclusion LIPUS can promote the formation of cartilage matrix,while pioglitazone has more pronounced anti-inflammatory effects.Both LIPUS and pioglitazone may be involved in the anti-inflammatory,COL2 synthesis process of OA chondrocytes through the PPAR?/NF-?B/i NOS pathway,resulting in the protective effect on OA chondrocytes.