Drastic changes in the tissue-specific expression of secreted phospholipases A2 in chicken pulmonary disease

Abstract

Infectious bronchitis is one of the most important diseases in poultry and it causes major economic losses. Infectious bronchitis is an acute, highly contagious, viral disease of chickens, characterized by rales, coughing, and sneezing. Because secreted phospholipases A2 (sPLA2) are involved in inflammatory processes, the gene expressions of sPLA2s were investigated in both healthy chickens and chickens with infectious bronchitis and lung inflammation. The draft chicken genome was first scanned using human sPLA2 sequences to identify chicken sPLA2s (ChPLA2), chicken total mRNA were isolated and RT-PCR experiments were performed to amplify and then sequence orthologous cDNAs. Full-length cDNA sequences of ChPLA2-IB, -IIA, -IIE, -V and -X were cloned. The high degree of sequence identity of 50-70% between the avian and mammalian (human and mouse) sPLA2 orthologs suggests a conservation of important enzymatic functions for these phospholipases. Quantitation by qPCR of the transcript levels of ChPLA2-IB, -IIA, -IIE, -V and -X in several tissues from healthy chicken indicated that the expression patterns and mRNA levels diverged among the phospholipases tested. In chicken with infectious bronchitis, an over expression of ChPLA2-V was observed in lungs and spleen in comparison with healthy chicken. These findings suggest that ChPLA2-V could be a potential biomarker for lung inflammation. Conversely, a down regulation of ChPLA2-IB, -IIA and -X was observed in lungs and spleen in case of infectious bronchitis. A significant increase in the expression level of ChPLA2-X and ChPLA2-IB was also noticed in pancreas. No or minor changes have been detected in the expression of ChPLA2-IIE in lungs and small intestine, but it shows a significant increase in several infected tissues.

Biochemical, Kinetic and Biological Properties of Group V Phospholipase A2 from Dromedary

“…Each sPLA 2 showed a distinctive expression profile in all cell types within restricted tissues. As described previously in cellular studies, sPLA2-V revealed their involvement in the inflammatory processes [ 24 ], but the biochemical and enzymatic properties of this current enzyme have been poorly documented until now. We report, as the first step towards understanding the structure, function and regulation of this PLA 2 , the production and characterization of DrPLA 2 -V. Evaluation of the antimicrobial effect of the enzyme and its cytotoxicity is also studied.…”

“…As described previously, sPLA 2 -V has been shown to be principally implicated in the inflammatory processes [ 24 ], but the biochemical and enzymatic properties of this essential enzyme have been indistinct. In order to gain further insights onto its mode of action with regard to phospholipids, we reported the enzymatic catalysis and the biological functions of this PLA 2 , purified from dromedary heart tissue.…”

“…Comparable results were obtained previously with mammalian PLA 2 -Vfrom various species showing a good stability at high temperature [ 40 ] Moreover, CaCl 2 (4 mM) was found as the best activator of the PLA 2 activity of pure DrPLA 2 -V , followed by Mg 2+ (combined with 1 Mm CaCl 2 ). All crystal structures of sPLA2 have a ‘calcium binding loop’ in the protein [ 41 ] and the calcium dependence of the group V PLA2 is similar to that of the human group IIA PLA 2 [ 24 ].…”

The Finding of a Group IIE Phospholipase A2 Gene in a Specified Segment of Protobothrops flavoviridis Genome and Its Possible Evolutionary Relationship to Group IIA Phospholipase A2 Genes

“…Abbreviations: Bt , Bos taurus ; Cf , Canis lupus familiaris ; Gg , Gallus gallus ; Mc , Macaca mulatta ; Oa , Ornithorhynchus anatinus ; Oc , Oryctolagus cuniculus ; and Pn, Pan troglodytes . References: Bt IIEPLA 2 (NP_001179015) [ 33 ], Cf IIEPLA 2 (XP_544525) (automated computational prediction by GNOMON); Dt Dis-2 (AFH66959) [ 17 ]; Gg IBPLA 2 (NP_001138961) [ 34 ]; Gg IIEPLA 2 (NP_001171878) [ 35 ]; Hs IBPLA 2 (NP_000919) [ 36 ]; Hs IIAPLA 2 (NP_001155199) [ 37 ]; Hs IICPLA 2 (NP_001099042) [ 38 ]; Hs IIDPLA 2 (NP_036532) [ 39 ]; Hs IIFPLA 2 (NP_073730) [ 40 ]; Hs VPLA 2 (NP_000920) [ 38 ]; Lm Lei-2 (AFH66961) [ 17 ]; Lm Lei-3 (AFH66962) [ 17 ]; Mc IIEPLA 2 (XP_001094364) (automated computational prediction by GNOMON); Mm IBPLA 2 (NP_035237) [ 41 ]; Mm IIAPLA 2 (NP_001076000) [ 42 ]; Mm IICPLA 2 (NP_032894) [ 41 ]; Mm IIDPLA 2 (NP_035239) [ 39 ]; Mm IIFPLA 2 (NP_036175) [ 20 ]; Mm VPLA 2 (NP_001116426) [ 41 ]; Oa IIEPLA 2 (XP_001505559) (automated computational prediction by GNOMON); Oc IIEPLA 2 (XP_002716050) (automated computational prediction by GNOMON); Oo IIEPLA 2 (this work); Pe IIEPLA 2 (this work); Pf IIEPLA 2 (this work); Pn IIEPLA 2 (XP_001163677) (automated computational prediction by GNOMON); and Pt IIEPLA 2 (this work).…”

Efficacy of Ban-Qin-Fei-Re-Qing oral liquid on avian infectious bronchitis

“…Avian infectious bronchitis (IB) is characterized by acute and high contact and often manifesting clinical signs across multiple organ systems, including the respiratory tract, digestive system, and urogenital system [1]. IB not only has major clinical symptoms, such as sneezing, tracheal rales, and coughing [2], but also affects the quality of laying hens and the performance of broilers, which causes large economic losses in the poultry breeding industry.…”