Extracellular matrix(ECM)pathway involved in skin immune response of Cynoglossus semilaevis upon Vibrio vulnificus infection

Half-smooth tongue sole(Cynoglossus semilaevis)is regarded as a significant commercial marine fish species in China,and frequent outbreaks of vibriosis has led to substantial economic losses.In this study,we investigated the molecular mechanisms underlying the involvement of the extracellular matrix(ECM)signaling pathway in the skin immune response of C.semilaevis infected with Vibrio vulnificus.The results showed that most differentially expressed proteins(DEPs)were identified through iTRAQ proteome analysis,and ten ECM-related proteins were screened at 12 and 36 h post-infection(hpi).Notably,several DEPs associated with ECM including HSPG,FN,COCH,LAMB1,LAMC1,TSPN,COL6A1,AMBP,HX and ITGA6 were tested for their expression at the transcriptional level during V.vulnificus infection using qRT-PCR assay.The analysis of protein-protein interaction(PPI)showed that the integrin ITGA6 exhibited obvious interactions among ECM-related DEPs.Furthermore,the spatio-temporal expression of the Csitga6 gene was highest in the skin,gill,muscle,and spleen,but lower in the liver,kidney and intestine.To our knowledge,this is the first report on the involvement of ECM pathway in the skin immune response to V.vulnificus infection,and provides a reference for further study of the ECM mechanism in the mucosal immune response of marine fish.

Transcriptomic analysis of regenerated skins reveals key genes involved in skin immune response and air-breathing of loach(Paramisgurnus dabryanus)

Fish skin acts as the first immune barrier against pathogens from external environments.Recently,fish skin immunity research has gradually become a hot topic in aquaculture disease control.Interestingly,the skin can do air-breathing in some bimodal respiration fish.However,there is no comprehensive understanding of these two functions.In this study,the skin regeneration of loach(Paramisgurnus dabryanus)was investigated through morphological and histological observations.Then,original skins(OS)and the regenerated skins(RS)when their capillaries were the most abundant during healing,were collected for transcriptomic analysis.285,899,386 clean reads with a total length of 42.34 Gb were obtained.A total of 1282 differentially expressed genes(DEGs)were detected,including 1030 DEGs up-regulated and 252 DEGs down-regulated in the comparison of RS vs.OS.Fc gamma R-mediated phagocytosis(containing gelsolin(Gsn)),chemokine signaling pathway(containing C-C motif chemokine ligand 28(Ccl28)),and B cell receptor signaling pathway(containing CD80 molecule(Cd81))were closely related to skin immune response of the loach.PI3K-Akt signaling pathway[containing fibronectin 1(Fn1)and lysyl oxidase-like 2b(Loxl2b)],TGF-beta signaling pathway[containing thrombospondin 1(Thbs1)],ECM-receptor interaction[containing integrin alpha 7(Itga7),Itgb8,Itgb10 and Itgb5],and dilated cardiomyopathy[containing laminin subunit alpha1(Lama1)]were closely associated with skin air-breathing of the loach.This study is conducive to explore the molecular mechanisms of skin immune response during its regeneration and air-breathing of bimodal respiration fish.This study will benefit for the aquaculture of P.dabryanus and its related species.

Effects of combined radiation and thermal burn injury on the survival of skin allograft and immune function in rats

Abstract Objectives To investigate the effects of combined radiation and thermal burn injury on the survival of skin allografts and to analyze the relationship between the prolongation of allograft survival and the changes of immune functions of the thymocytes and splenocytes in rats. Methods Wistar rats were irradiated with 3, 4, 5, 6 and 8 Gy of gamma rays. Thirty minutes after radiation, 15% TBSA Ⅲ degree burn was inflicted to the rats. Twenty four hours after the burn injury, allografts were used to cover the burn wounds. In the 8 Gy group, 1 hour before skin grafting, the bone marrow cells (4×10 8) from the same donor were also transplanted. All rats were carefully observed after injury. The rats with single radiation injury of 5 Gy gamma rays, with single burn injury and with combined radiation burn injury were killed 3, 7, 10, 15 and 30 days after skin grafting for immunological assay and pathological study. Results All the allografts in the single burn group were rejected in 10 days. In the combined injury groups, the survival rates of the allografts in rats undergoing 3 and 4 Gy radiation were 20% and 30%, respectively. In the combined injury groups undergoing 5, 6 and 8 Gy radiation, the 10 day survival rates of the allografts were 69%, 88% and 100% respectively, and the 30 day survival rates in the three groups were 36%, 42% and 100% separately. The grafted allogenic skin, with normal epithelial cells and good vascularity, healed well with the recipient's skin. Hairs grew well from the allografts 30 days after grafting. Three, 7 and 15 days after allografting, in the single burn group, the proliferative activities of the thymocytes were 90%, 185% and 130% of the preinjury level, and the antibody forming capacities of the splenocytes were 200%, 171% and 300% of the preinjury level, respectively; in the combined injury groups, the proliferative activities were 6%, 99% and 91% of the preinjury level, and the forming capacities were 2%, 36% and 90% of the preinjury level. Conclusions The survival rate of allograft in rats undergoing combined radiation and thermal burn injury rises with the increase in radiation dosage. The allograft covering single bun injury is severely rejected by immune reaction. The prolongation of the survival of allograft in combined injury group mainly results from radiation that suppresses immune functions.