The Effect Of Recombinant Protein GSTA3 And Ex-FABP On The MRNA Expression Of Host Defense Peptide In TD-induced Chicken Erythrocytes

In tibial dyschondroplasia(TD)studies,thiram has been used to induce TD with high regularity and precision for young broiler chicks.As one of Glutathione S-transferase(GSTs),the GSTA3 is involved in detoxification,antioxidative stress,synthesis of steroids and prostaglandins.As a member of fatty acid-binding protein,the expression of extracellular fatty acid-binding protein(Ex-FABP)is closely related to the development of TD.Chicken erythrocyte,which is the most abundant cell subset in blood vessel,also exists in cartilage zone.It has recently been shown that chicken erythrocytes constitutively express toll-like receptors(TLRs)and cytokines,which raises the possibility that chicken erythrocytes also contribute to the prevention and treatment of bone diseases including TD.In this study,RT-PCR has been used to explore whether host defense peptides(HDPs)are expressed in chicken erythrocytes.In addition,we also explored the effects of recombinant chicken GSTA3 and Ex-FABP proteins on TD by detecting the changes of the mRNA expression of HDPs in chicken erythrocyte after the treatment of different doses of recombinant chicken GSTA3 and Ex-FABP proteins during the development of TD.Our results were as follows:(1)The mRNA expression of 11 types of HDPs(AvBD1,AvBD2,AvBD3,AvBD4,AvBD5,AvBD6,AvBD7,AvBD9,LEAP-2,CATH-2 and NK-lysin)was identified in chicken erythrocytes.(2)The effect of recombinant GSTA3 protein on the expression of HDPs transcripts in chicken erythrocytes was different.The toxic effect of thiram suppressed many HDPs expression and led to the necrosis of growth plate chondrocyte and angionecrosis.The recombinant GSTA3 protein promoted the immune response by up-regulating the expression of HDPs.(3)Significant differences in the transcriptional expression of HDPs could be regulated by different doses of recombinant Ex-FABP protein at different stages of TD.The mRNA expression of HDPs could be promoted the immunomodulatory effects of chicken erythrocytes by different doses of Ex-FABP protein and accelerates the recovery of growth plate lesions.The results of this study showed that the transcripts of many types of HDPs were expressed in chicken erythrocytes.In addition,the recombinant GSTA3 and Ex-FABP proteins might participate in promoting the expression of HDPs in chicken erythrocytes during the development of TD.All above clues suggested that the recombinant GSTA3 and Ex-FABP proteins might play a role in the recovery of TD,which provided a new possibility for the prevention and treatment of TD in future.