Biochemical and morphological attributes of broiler kidney in response to dietary glucocorticoid, dexamethasone.

Glucocorticoids (GCs) initiate oxidative stress and cause renal damage which lead to hypertension, heart failure and ultimately death. The current study aimed to investigate the alterations in serum biochemical parameters i.e. HDL and LDL; gross anatomy, histomorphology and histomorphometry of broiler kidney in response to dietary GC, dexamethasone (DEX). Day old chicks (DOCs) were randomly assigned into four groups: control and three treatment groups (T1, T2 and T3). The control group was fed commercial broiler type ration and the treated groups were fed commercial broiler type ration containing GC (Dexamethasone @ 3, 5 and 7 mg/kg in T1, T2 and T3 group respectively). To measure the biochemical parameters, blood samples were collected on days 7, 14, 21, and 28 of the experiment. For histological investigation, kidney (left) samples were collected from the individual birds after sacrificing on days 7, 14, 21, and 28 of the experiment. Histomorphological alterations of the kidney were assessed by routine hematoxylin and eosin (H&E) staining. Biochemical analysis showed significantly increased serum HDL and LDL level compared to the control. In gross study, dark congested kidney was found with significantly decreased weight, length and width. Treatment with DEX augmented congestion, inflammation and fibrosis in kidney, as evidence by histomorphometric study. Extensively degenerated and atrophied glomeruli, degenerated tubular epithelium with distorted tubules and inter tubular empty spaces were seen. Percentage of atrophied glomeruli increased significantly and maximum percentage of glomerular atrophy was seen at day 28. These changes were found more explicitly in the higher dose group. Histomorphometric study also revealed significant decrease in the diameter of glomerulus. The findings of this study suggest that DEX may alter the serum biochemical parameters as well as kidney gross and histomorphology.

PBMCs transcriptome profiles identified breed-specific transcriptome signatures for PRRSV vaccination in German Landrace and Pietrain pigs.

Porcine reproductive and respiratory syndrome (PRRS) is a devastating viral disease affecting the swine industry worldwide. Genetic variation in host immunity has been considered as one of the potential determinants to improve the immunocompetence, thereby resistance to PRRS. Therefore, the present study aimed to investigate the breed difference in innate immune response to PRRSV vaccination between German Landrace (DL) and Pietrain (Pi) pigs. We analyzed microarray-based transcriptome profiles of peripheral blood mononuclear cells (PBMCs) collected before (0 h) and 24 h after PRRSV vaccination from purebred DL and Pi pigs with three biological replicates. In total 4,269 transcripts were identified to be differentially expressed in PBMCs in at least any of four tested contrast pairs (i.e. DL-24h vs. DL-0h, Pi-24h vs. Pi-0h, DL-0h vs. Pi-0h and DL-24h vs. Pi-24h). The number of vaccine-induced differentially expressed genes (DEGs) was much higher (2,459) in DL pigs than that of Pi pigs (291). After 24 h of PRRSV vaccination, 1,046 genes were differentially expressed in PMBCs of DL pigs compared to that of Pi (DL-24h vs. Pi-24h), indicating the breed differences in vaccine responsiveness. The top biological pathways significantly affected by DEGs of both breeds were linked to immune response functions. The network enrichment analysis identified ADAM17, STAT1, MMS19, RPA2, BAD, UCHL5 and APC as potential regulatory genes for the functional network of PRRSV vaccine response specific for DL; while FOXO3, IRF2, ADRBK1, FHL3, PPP2CB and NCOA6 were found to be the most potential hubs of Pi specific transcriptome network. In conclusion, our data provided insights of breed-specific host transcriptome responses to PRRSV vaccination which might contribute in better understanding of PPRS resistance in pigs.

PBMC transcriptome profiles identifies potential candidate genes and functional networks controlling the innate and the adaptive immune response to PRRSV vaccine in Pietrain pig.

The porcine reproductive and respiratory syndrome (PRRS) is a devastating viral disease affecting swine production, health and welfare throughout the world. A synergistic action of the innate and the adaptive immune system of the host is essential for mounting a durable protective immunity through vaccination. Therefore, the current study aimed to investigate the transcriptome profiles of peripheral blood mononuclear cells (PBMCs) to characterize the innate and the adaptive immune response to PRRS Virus (PRRSV) vaccination in Pietrain pigs. The Affymetrix gene chip porcine gene 1.0 ST array was used for the transcriptome profiling of PBMCs collected at immediately before (D0), at one (D1) and 28 days (D28) post PRRSV vaccination with three biological replications. With FDR <0.05 and log2 fold change ±1.5 as cutoff criteria, 295 and 115 transcripts were found to be differentially expressed in PBMCs during the stage of innate and adaptive response, respectively. The microarray expression results were technically validated by qRT-PCR. The gene ontology terms such as viral life cycle, regulation of lymphocyte activation, cytokine activity and inflammatory response were enriched during the innate immunity; cytolysis, T cell mediated cytotoxicity, immunoglobulin production were enriched during adaptive immunity to PRRSV vaccination. Significant enrichment of cytokine-cytokine receptor interaction, signaling by interleukins, signaling by the B cell receptor (BCR), viral mRNA translation, IFN-gamma pathway and AP-1 transcription factor network pathways were indicating the involvement of altered genes in the antiviral defense. Network analysis revealed that four network modules were functionally involved with the transcriptional network of innate immunity, and five modules were linked to adaptive immunity in PBMCs. The innate immune transcriptional network was found to be regulated by LCK, STAT3, ATP5B, UBB and RSP17. While TGFß1, IL7R, RAD21, SP1 and GZMB are likely to be predictive for the adaptive immune transcriptional response to PRRSV vaccine in PBMCs. Results of the current immunogenomics study advances our understanding of PRRS in term of host-vaccine interaction, and thereby contribute to design a rationale for disease control strategy.

Effects of dexamethasone on the morphometry and biometry of immune organs of broiler chicken / Efectos de la dexametasona en la morfometría y biometría de los Órganos Inmunes del pollo de engorde

The study was conducted to examine the histological changes i.e. morphology and biometry of immune organs (thymus, spleen and bursa cloacalis or «Fabricius¼) of broilers in response to dietary dexamethasone (DEX). The day old chicks were obtained from the commercial hatchery and randomly divided into two groups i.e. control and experimental or treated group. The control group was reared on commercial broiler ration and the experimental group (n=25) was maintained on commercial broiler ration with corticosteroid (Dexamethasone-Decason, BP 0.5 mg, Opsonin @ 7 mg/kg feed). Samples (bursa cloacalis, spleen, and thymus) were collected from the ten control and ten experimental broilers at 14 and 28 days of experiment; then tissues were stained with Hematoxylin and Eosin. The biometric measurements of the samples were performed by the calibrated stage micrometer. Finally, the obtained data were analyzed using GraphPad Prism 8 software. In DEX treated group, the morphology of thymus, spleen and bursa cloacalis did not show any abnormal alterations. But their development rate was slower on visual inspection in DEX treated group. The length and width of bursal follicle of bursa cloacalis, thymic lobule of thymus and white pulp of spleen were statistically consisted but numerically decreased in DEX treated group than the control. The present findings suggested that DEX does not affect the histological architectures of immune organs except causing developmental arrest. Numerical decrease in the biometry of immune organs indicates that DEX causes apoptosis of immune cells in lymphoid organs of broiler.

El estudio se realizó para examinar los cambios histológicos, es decir, la morfología y la biometría de los órganos inmunes (timo, bazo y bolsa cloacal) de pollos de engorde en respuesta a la dexametasona en la dieta (DEX). Los pollitos de un día se obtuvieron de un criadero comercial y se dividieron aleatoriamente en dos grupos, control y experimental. El grupo control se crió con una ración comercial de pollos de engorde y el grupo experimental (n = 25) se mantuvo con una ración comercial de pollos de engorde con corticosteroides (DexamethasoneDecason, BP 0,5 mg, Opsonin @ 7 mg/kg). Se recogieron muestras (bolsa cloacal, bazo y timo) de los diez pollos del grupo control y diez del grupo de engorde experimental, a los 14 y 28 días de experimento. Luego, los tejidos se tiñeron con hematoxilina y eosina. Las mediciones biométricas de las muestras fueron realizadas con un micrómetro calibrado. Finalmente, los datos obtenidos se analizaron utilizando el software GraphPad Prism 8. En el grupo tratado con DEX, la morfología del timo, el bazo y la bolsa cloacal no mostraron alteraciones anormales. Pero su tasa de desarrollo fue más lenta en la inspección visual en el grupo tratado con DEX. La longitud y el ancho del folículo bursal de la bolsa cloacal, el lóbulo tímico del timo y la pulpa blanca del bazo fueron estadísticamente consistentes, pero disminuyeron numéricamente en el grupo tratado con DEX en relación al control. Los hallazgos actuales sugirieron que DEX no afecta la arquitectura histológica de los órganos inmunes, excepto que causa una detención del desarrollo. La disminución numérica en la biometría de los órganos inmunes indica que DEX provoca apoptosis de las células inmunes en los órganos linfoides de los pollos de engorde.