Myocardial expression of transforming growth factor beta family and endothelin-1 in the progression from heart failure to ascites in broilers with cold-induced pulmonary hypertension.

We determined mRNA expression of genes of endothelin-1 (ET-1), and of the transforming growth factor beta ligands (TGFß1, TGFß2 and TGFß3), their receptors (TßRI and TßRII) and their pseudoreceptor BAMBI in the heart of broilers raised under cold temperature conditions and affected by pulmonary hypertension. Gene expression was determined by RT-qPCR in right myocardial ventricle samples from 4-week-old chickens (n = 48) raised either under normal (control) or cold temperature conditions (22 °C versus 14 °C). We do not find differences among healthy birds, birds with cardiac failure and ascitic birds in the mRNA levels of TGFß2, TGFß3 and BAMBI. In the control group, ET-1 mRNA level was increased in the ascitic birds as compared with healthy birds and birds with cardiac failure (p < 0.05) whereas in the cold treated group, no increase was observed (p > 0.05); yet, ascitic birds in the cold group showed lower mean than ascitic birds in the control group (p < 0.05). TßRII mRNA expression was higher in ascitic than in healthy birds (p < 0.05) in both control and cold treated groups; however, in the ascitic birds of the cold treated group TßRII expression was lower than in ascitic birds from the control group (p < 0.05). Thus, the higher ET-1 and TßRII levels observed in ascitic birds seem to be attenuated by cold.

Over, and underexpression of endothelin 1 and TGF-beta family ligands and receptors in lung tissue of broilers with pulmonary hypertension.

Transforming growth factor beta (TGF ß ) is a family of genes that play a key role in mediating tissue remodeling in various forms of acute and chronic lung disease. In order to assess their role on pulmonary hypertension in broilers, we determined mRNA expression of genes of the TGF ß family and endothelin 1 in lung samples from 4-week-old chickens raised either under normal or cold temperature conditions. Both in control and cold-treated groups of broilers, endothelin 1 mRNA expression levels in lungs from ascitic chickens were higher than levels from healthy birds (P < 0.05), whereas levels in animals with cardiac failure were intermediate. Conversely, TGF ß 2 and TGF ß 3 gene expression in lungs were higher in healthy animals than in ascitic animals in both groups (P < 0.05). TGF ß 1, T ß RI, and T ß RII mRNA gene expression among healthy, ascitic, and chickens with cardiac failure showed no differences (P > 0.05). BAMBI mRNA gene expression was lowest in birds with ascites only in the control group as compared with the values from healthy birds (P < 0.05).