The Expression And Significance Of GDNF/PROKR1and Proks/PROKRs Signaling Pathways In The Hirschsprung’s Disease

Objective:To explore the correlation of GDNF/PROKR1and Proks/PROKRs signaling pathways with pathogenesis of aganglionosis, reveal the significant role of GDNF/PROKR1and Proks/PROKRs signaling pathways in development of human enteric neural crest derived cells, and provide the theory basis for diagnosis and treatment for aganglionosisMethods:Specimens were collected from resected colon in both aganglionic bowel segments and ganglionic segments of30aganglionosis patients in the Tianjin Children’s Hospital. All of both underwent haematoxylin and eosin (HE) staining, followed by immunohistochemical staining for Prokl, Prok2, PROKR1, PROKR2, MAPK, AKT and GDNF. Morphometric analysis of each sample was performed by image analysis program (Image-Pro-Plus).Mean density of each sample neurons was evaluated at400magnifications. Statistical analyses were performed using the SPSS17.0software package. Significance was defined as P＜0.05.Results:1. Prokl and Prok2immunohistochemical staining was negative in nerve plexus of the narrow segments of aganglionosis group. Prokl was negative in the dilated segments of aganglionosis, but Prok2was positive.2. PROKR1immunohistochemical staining was strongly positive in ganglionic cells both in the myenteric and submucosal plexuses in the dilated segments of aganglionosis, but was negative in most of (about92.2%) the narrow segments of aganglionosis group. PROKR2was positive in ganglionic cells of the dilated segments of aganglionosis, but was negative in most of (about98.5%) the narrow segments of aganglionosis group.3. Semi-quantitative analysis showed the following content:(1) Mean density of prokineticinl and prokineticin2was zero in the aganglionic segments of aganglionosis. Meanwhile, prokineticinl was zero in the ganglionic segments, but prokineticin2was0.14529±0.057628.(2) Mean density of prokineticinl receptor was0.033521±0.012114in the aganglionic segments of aganglionosis, was0.31634±0.108397in the ganglionic segments of aganglionosis ((P＜0.01). At the same time, mean density of prokineticin2receptor was0.02058±0.00863in the aganglionic segments of aganglionosis, was0.20781±0.087942in the ganglionic segments of aganglionosis ((P<0.01).(3) Prokl was showed a same expression as PROKR1, PROKR2in the ganglionic segments of aganglionosis.(4) PROKR1was showed a same expression as GDNF, MAPK and AKT in the ganglionic segments of aganglionosis.(5) PROKR2was showed a same expression as MAPK and AKT in the ganglionic segments of aganglionosis.Conclusion:1. Prok2was positive in ganglionic cells in the ganglionic segments of aganglionosis groups, but Prokl is negative. Prok2could be an important role in pathogenesis of aganglionosis.2. Prok2could be an important role in pathogenesis of aganglionosis through its receptor which were PROKR1and PROKR2.3. PROKRland PROKR2might mediate a signaling pathway through MAPK/ERK and PI3K/Akt supporting proliferation/survival and differentiation of precursor cells during neuron development.4. PROKRland GDNF might mediate a signaling pathway through MAPK/ERK and PI3K/Akt supporting proliferation/survival and differentiation of precursor cells during neuron development. PROKR1expression deficit is closed related to the pathogenesis of human enteric neural crest derived cells; it could be an important role in pathogenesis of aganglionosis.