Increase in pro-apoptotic Bax expression and decrease in anti-apoptotic Bcl-2 expression in newborns with necrotizing enterocolitis

Background/Aim. The aim of the present study was to find out if there is an increase in the expression of pro-apoptotic Bax and reduction in expression of anti-apoptotic Blc-2A1 in newborn intestines with necrotizing enterocolitis (NEC). Material and Methods. We compared 8 consecutive newborn patients undergoing bowel resection for NEC with 8 neonates undergoing intestinal resection for ileal atresia. Histopathological evaluation of tissue injury and apoptosis was performed by using light microscopic examination and TUNEL method. The mRNA level of apoptotic (CASP3, CASP6, CASP7, Bax, BIRC2) and anti-apoptotic genes were evaluated by PCR array method. Protein expression was assessed by immunohistochemistry. Results. Tissue injury scores and mean apoptosis scores were significantly higher in NEC group when compared with control group (p < 0.01). Expression of pro-apoptotic genes were significantly increased in NEC group when compared with control group (p < 0.01). Expression of anti-apoptotic Bcl-2A1 gene was significantly decreased in NEC group, (p < 0.01). Protein expression of Bax and CASP3 was significantly increased in NEC group, (p < 0.01). Conclusion. Our data in human newborns suggest that alteration of the balance between pro-apoptotic Bax expression and antiapoptotic Bcl-2A1 expression in the site of injury is a possible mechanism in the pathogenesis of NEC.