Modulation of molecular markers in the duodenum and jejunum of piglets induced by an isotonic protein mixture

The article presents an analysis of the results that allow to evaluate isotonic protein mixture (IPM) effect on the barrier function of the digestive tract of piglets in the early postnatal period, which is important for development of new preventive and curative strategies in pigs farming. The study was carried out with involving the piglets of the early postnatal period, which were divided in control and experimental groups. The expression of molecular markers in the duodenum and jejunum was determined in the animals of 9, 21 and 35 days of age. It was found that in IPM-exposed piglet group on the 9th day of life E-cadherin level in duodenum intestines exceeded control group content by 50.1% (P<0.001), and the level of fibronectin (FN) exceeded control group content by 55.3% (P<0.001). After weaning another increase of following factors was observed: E-cadherin level exceeded control values by 59.5%, and the level of FN – by 56.3% (P<0.001). The level of tumor necrosis factor-α (TNF-α) in piglets of the experimental groups was much lower than in controls animals: on the 9th day its concentration was decreased by 18.0% (P<0.01), and after weaning remained 62.0% lower (P<0.001). The level of caspase-3 (Casp-3) in the duodenum intestine of experimental piglet group after weaning remained relatively stable and was 60.7% lower (P<0.001) in compare with the control group. The expression of molecular markers in the jejunum of piglets underwent gradual changes, in particular, by the 21st day of life the level of E-cadherin increased by 4.0% (P<0.05), however, after weaning (by the 35th day) its expression increased by another 9.4% (P<0.05). A similar dynamic trend was observed for FN, the level of which reached 113.8 ± 4.0%. At the same time TNF-α levels increased by 72.5% (P<0.01), and Casp-3 by 65.1% (P<0.01). In piglets receiving IPM on the 9th day of life, the level of E-cadherin was 32.1% higher comparing to the control group (P<0.001). Although by the 21st day there was a decrease of E-cadherin content (by 9.0%), contrary, E-cadherin level increased by 22.2% (P<0.01) again after weaning. FN has also demonstrated similar dynamics, with its level being 58.9% higher compared to control (P<0.001). The most drastic changes were observed in the TNF-α content while its level remained 90.6% lower compared to the control group (P<0.001). The level of Casp-3 in the thin intestine of experimental piglet groups remained stable low, being 60.1% lower than the control level (P<0.001). The present results demonstrated a multifactorial beneficial effect of IPM supplementation on the gut barrier functioning, the balance in pro-/anti-inflammatory cytokines, and the inhibition of apoptosis in piglets.