Abstract
The piglets with postnatal growth retardation (PGR) have high mortality and morbidity during their growth and development. Abnormal development of small intestine is casually implicated in impaired growth, but the exact mechanism still remains poorly understood. Thus, the present study investigated the immune profiles related to intestinal mucosal barrier in PGR and healthy piglets. The plasma sample, middle segments of small intestine, and the intestinal mucosa were obtained from healthy and PGR piglets at 42d of age. Compared to healthy piglets, higher plasma concentrations of diamine oxidase and D-lactate were observed in PGR piglets (P < 0.05). Decreased villous height, ratio of villous height to crypt depth, as well as sparse villi, jagged microvilli were also found in jejunum and ileum of PGR piglets. PGR also decreased the percentage of proliferating cell nuclear antigen (PCNA)-positive cells, as well as abundance of Zonula occludens-1, Occludin, Claudin-1, and E-cadherin mRNA and protein in jejunal and ileal mucosa (P < 0.05). The lower concentration of sIgA in jejunal mucosa, and lysozyme in both jejunal and ileal mucosa, but higher level of β-defensins in the ileal mucosa were observed in PGR piglets as compared to healthy piglets (P < 0.05). The percentage of CD68-positive cells were significantly increased, but the levels of P-glycoprotein were decreased in jejunum and ileum from PGR piglets (P < 0.01). Moreover, the expression of proteins involved in p38 MAPK/NF-kB pathway was significantly upregulated in jejunal and ileal mucosa from PGR piglets (P < 0.05). Collectively, these results indicated that the PGR piglets exhibited impaired intestinal integrity, and decreased capacity of mucosal immune function, which may result in severe inflammatory response via the activation of p38 MAPK/NF-kB pathway. Our findings may have important implications in the prevention and treatment of the intestinal mucosal barrier dysfunction in piglets.
92 Postnatal growth retardation impairs intestinal mucosal barrier in piglets