Treatment Of Chicken Growth Plates By HIF-1? And Hsp90 Inhibitors In Thiram Induced Tibial Dyschondroplasia

Tibial dyschondroplasia(TD)is an important tibiotarsal bone disorder characterized by avascular and non-mineralized growth plate and is attributed to abnormal differentiation of chondrocytes and lameness.It causes major animal welfare concern and economic losses to poultry industry.1.The effect of inhibition of Hypoxia-Inducible Factor-1? in thiram-induced tibial dyschondroplasiaThe aim of present study was to evaluate the effects of hypoxia-inducible factor-1?(HIF-1?)inhibition in thiram induced TD by using synthetic medicine FK228(C24H36N4S6O2)and association between HIF-1? and heat-shock protein 90(Hsp90).One hundred and fifty broiler chicks were equally divided into 3 groups: control;thiram fed;and FK228 treatment group.Expressions of HIF-1?,Hsp90 and vascular endothelial growth factor(VEGF)and Flk-1 were analyzed by quantitative real-time polymerase chain reaction(RT-q PCR)on day 10 and 14 while western blot(WB)analysis was performed to measure the protein levels of HIF-1? and Hsp90 at the end of the experiment.Results showed that HIF-1?,Hsp90 and VEGF m RNA levels were significantly(P<0.05)up regulated during the course of disease in thiram group as compared with the control group;however,the Flk-1 receptor levels were significantly down-regulated in TD-affected birds(P<0.05).HIF-1? inhibitor FK228 down regulated the m RNA and protein levels of HIF-1? and Hsp90 significantly with diminishes growth plate size and lameness.In conclusion,there is a close association between HIF-1? and Hsp90 and they play a role in the formation of avascular growth plate,accordingly HIF-1? inhibition factor may target in to prevent and control avascular growth plate and lameness in chicken broiler.2.Recovery of chicken growth plates by Hsp90 inhibitor EGCG and Apigenin in thiram induced tibial dyschondroplasiaHeat-shock protein 90(Hsp90)is a pro-angiogenic factor in animal tissues;however;its gene expression increases in case of chicken TD.The objective of this study was to evaluate the efficacy of Epigallocatechin-3-gallate(EGCG)and Apigenin in thiram induced TD birds due to their Hsp90 inhibitory activities.The histological study of growth plates was carried out with H&E staining,and the Hsp90 gene expression was examined by reverse transcription quantitative real-time polymerase chain reaction(RT-q PCR).Results showed that as compared to control group,TD had displayed the changes in chondrocytes differentiation with lack of blood vessels;and an increased expression of Hsp90 was observed significantly(P<0.05).However,on administering the EGCG and Apigenin to TD-affected birds,the normal chondrocytes columnar organization was restored with vascularization and decreased Hsp90 expression activity(P<0.05)which ultimately abrogated the lameness.Our results suggested that Hsp90 is the key factor in the development of TD,EGCG and Apigenin have a novel effect on Hsp90 inhibition properties thus reducing the lameness and leg deformity in chicken broiler.3.Healing of growth plate cartilage by hypoxia Inducible Factor-1? inhibitor Apigenin on thiram induced tibial dyschondroplasiaThis study was designed to understand the mechanism of hypoxia-inducible factor-1?(HIF-1?)inhibition and antioxidant capacity of Apigenin in thiram induced TD.One hundred and fifty broiler chicks were equally divided into 3 groups: control;thiram fed;and Apigenin group.The genotypic expression of HIF-1? was analyzed by using quantitative real-time polymerase chain reaction(RT-q PCR)at day 10 and day 14 of the experiment.The results showed that HIF-1? m RNA levels were significantly(P<0.05)up regulated during the course of disease in thiram induced TD birds as compared to control.However,the m RNA levels of HIF-1? was significantly down regulated by HIF-1? inhibition factor in Apigenin group with diminishes growth plate size and lameness.Moreover,thiram induction also increased the levels of AST,ALT and MDA contents in liver,whereas decreased the antioxidant enzymes(SOD;GSH-Px)and ALP values in thiram group,while these values were found close to normal range in Apigenin group as compared to control group in response to Apigenin.In conclusion,HIF-1? inhibition can heal lameness and avascularized growth plate in broiler chickens;moreover Apigenin may be efficient through rectifying the liver damage and oxidative imbalance caused by thiram.