Objective We have demonstrated that needle knife(acupotomy)treatment can improve knee osteoarthritis(KOA)in rabbits.The present study was designed to examine its effect on expression of phosphorylated focal adhesion kinase(p-FAK)

phosphinositides 3 kinase(p-PI 3 K)and Aggrecan genes and proteins in the knee-joint cartilage tissues of KOA rabbits

so as to explore its partial molecular mechanism underlying improvement of KOA.Methods Forty-nine New Zealand male rabbits were randomly divided into normal control

model

model+inhibitor

needle knife

needle knife+inhibitor

electroacupuncture(EA)

EA +inhibitor groups(n=7 in each).The KOA model was established by modified Videman method(left hindlimb extension immobilization and ankle dorsal flexion 60 O).Acupotomy relaxing manipulation was applied to the lateral collateral ligament and patellar ligament of the left knee-joint

two times a week for 4 weeks

and EA(2 Hz/100 Hz

3 mA)was applied to the left"Liangmen"(ST 21)

"Xuehai"(SP 10)

"Neixiyan"(EX-LE 4)and"Dubi"(ST 35)for 20 min

three times a week

for4 weeks.About 2 hbefore every needle-knife or EA treatment or at the corresponding time-point

intra-articular cavity injection of PF-562271(a specific antagonist of FAK

200 !mol/L

0.5 mL)was performed in the three inhibitor groups.The expression levels of p-FAK

p-PI 3 K

Aggrecan genes and proteins in the cartilage tissues were measured with quantitative Real-time PCR and Western blot

separately.Results After modeling

the expression levels of p-FAK and p-PI 3 Kgenes and proteins were significantly up-regulated(P<0.05

P<0.01)

while those of Aggrecan protein and mRNA considerably down-regulated in the model group in comparison with the normal group(P<0.01).Following 4 weeks' needle-knife or EA treatment

the expression levels of p-FAK and p-PI 3 Kand Aggrecan proteins in both EA and needle-knife groups

and Aggrecan mRNA in the needle knife group were significantly up-regulated(P<0.05

P<0.01).After administration of p-FAK antagonist

modeling-induced up-regulation of expression of p-FAK mRNA and protein and p-PI 3 Kprotein

as well as modeling-induced down-regulation of Aggrecan mRNA and protein were significantly suppressed in the model+inhibitor group(P<0.05

P<0.01)

and needle knife-induced and EA-induced up-regulation of expression of p-FAK

p-PI 3 Kand Aggrecan mRNAs and proteins was notably suppressed respectively in comparison with the needle knife and EA groups(P<0.05

P<0.01).The effect of needle knife was significantly superior to that of EA in up-regulating p-PI 3 Kand Aggrecan mRNAs as well as p-FAK

p-PI 3 Kand Aggrecan proteins(P<0.05

P<0.01).Conclusion Needle knife intervention can up-regulate the expression levels of p-FAK

p-PI 3 Kand Aggrecan proteins and mRNAs in the cartilage tissue of the knee-joint in KOA rabbits

suggesting an involvement of FAK-PI 3 Ksignaling in the needle knifeinduced improvement of KOA.