Diminished expression of ACTH signaling proteins and steroidogenic limiting factors in adrenocortical cells isolated from halothane nn pigs.
Previous studies demonstrated significantly lower plasma cortisol level in homozygous halothane-positive (Hal nn) pigs, as compared with homozygous halothane-negative (Hal NN) pigs. To determine whether such difference is attributed to the fundamental alterations in adrenocortical function, F1 offsprings from Pietrain (Hal nn)xErhualian (Hal NN) were intercrossed to produce F2 sibling pigs with segregated genotypes. Adrenocortical cells were isolated from the Hal nn and Hal NN F2 pigs, respectively, and cultured with or without ACTH challenge. Cortisol levels in culture medium, as well as the content of MC2R, cAMP, CREB, phosphorylated CREB (pCREB), StAR and P450scc in adrenocortical cell lysates, were determined. Cortisol, cAMP, StAR and P450scc levels were significantly lower in Hal nn adrenocortical cells under basal condition without ACTH challenge. ACTH significantly increased cortisol level in the medium and the protein content of MC2R, StAR, P450scc in adrenocortical cell lysates, regardless of genotypes. Total CREB protein content was not different between genotypes and treatments, whereas pCREB content exhibited significant effects of genotype and treatment, being higher in Hal NN than in Hal nn under basal condition and in response to ACTH challenge. These results indicate that the compromised cAMP/PKA/pCREB signaling pathway of ACTH and diminished expression of limiting factors in adrenocortical steroidogenesis (StAR and P450scc) may contribute to the significantly lower plasma cortisol levels in Hal nn pigs.
Li
Liu-An
LA
Key Laboratory of Animal Physiology & Biochemistry, Nanjing Agricultural University, Nanjing 210095, PR China.
Xia
Dong
D
Wei
Shi
S
Li
Xiao
X
Parvizi
Nahid
N
Zhao
Ru-Qian
RQ
D000302:Adrenal Cortex / Q000378:metabolism*; D000324:Adrenocorticotropic Hormone / Q000378:metabolism*; D018685:Anesthetics, Inhalation; D000818:Animals; D002478:Cells, Cultured; D002786:Cholesterol Side-Chain Cleavage Enzyme / Q000235:genetics / Q000378:metabolism; D000242:Cyclic AMP / Q000378:metabolism; D017362:Cyclic AMP Response Element-Binding Protein / Q000235:genetics / Q000378:metabolism; D017868:Cyclic AMP-Dependent Protein Kinases / Q000235:genetics / Q000378:metabolism; D015536:Down-Regulation / Q000235:genetics; D004351:Drug Resistance / Q000235:genetics; D004734:Energy Metabolism / Q000235:genetics / Q000502:physiology; D005838:Genotype; D006221:Halothane; D006720:Homozygote; D006854:Hydrocortisone / Q000097:blood; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism; D019837:Ryanodine Receptor Calcium Release Channel / Q000235:genetics*; D015398:Signal Transduction / Q000235:genetics*; D013256:Steroids / Q000096:biosynthesis*; D013552:Swine / Q000235:genetics* / Q000378:metabolism; D000098682:Steroidogenic Acute Regulatory Protein
D018685:Anesthetics, Inhalation; D017362:Cyclic AMP Response Element-Binding Protein; D010750:Phosphoproteins; D019837:Ryanodine Receptor Calcium Release Channel; D013256:Steroids; D000098682:Steroidogenic Acute Regulatory Protein; D000324:Adrenocorticotropic Hormone; D000242:Cyclic AMP; D002786:Cholesterol Side-Chain Cleavage Enzyme; D017868:Cyclic AMP-Dependent Protein Kinases; D006221:Halothane; D006854:Hydrocortisone