MicroRNA-15a - cell division cycle 42 signaling pathway in pathogenesis of pediatric inflammatory bowel disease

AIM

To determine whether cell division cycle (Cdc)42 is regulated by microRNA (miR)-15a in the development of pediatric inflammatory bowel disease (IBD).

METHODS

We cultured 293T cells, used plasmids and performed dual-luciferase assay to determine whether Cdc42 is a miR-15a target gene. We cultured Caco-2 cells, and stimulated them with tumor necrosis factor (TNF)-α. We then employed lentiviruses to alter the expression of miR-15a and Cdc42. We performed quantitative reverse transcription polymerase chain reaction (qRT-PCR) and immunofluorescence to determine whether Cdc42 is regulated by miR-15a in Caco-2 cells. Finally, we collected ileocecal tissue by endoscopy from patients and performed qRT-PCR to examine the expression of miR-15a and Cdc42 in pediatric IBD patients.

RESULTS

Target Scan and dual-luciferase assay revealed that Cdc42 was a miR-15a target gene. MiR-15a expression increased (P = 0.0038) and Cdc42 expression decreased (P = 0.0013) in cells stimulated with TNF-α, and the expression of the epithelial junction proteins zona occludens (ZO)-1 (P < 0.05) and E-cadherin (P < 0.001) decreased. Cdc42 levels decreased in miR-15a-mimic cells (P < 0.001) and increased in miR-15a inhibitor cells (P < 0.05). ZO-1 and E-cadherin decreased in miR-15a-mimic cells (P < 0.001) but not in the miR-15a inhibitor + TNF-α cells. In Lv-Cdc42 + TNF-α cells, ZO-1 and E-cadherin expression increased compared to the Lv-Cdc42-NC + TNF-α (P < 0.05) or miR-15a-mimic cells (P < 0.05). Fifty-four pediatric IBD patients were included in this study, 21 in the control group, 19 in the Crohn’s disease (CD) active (AC) group, seven in the CD remission (RE) group, and seven in the ulcerative colitis (UC) group. MiR-15a increased and Cdc42 decreased in the CD AC group compared to the control group (P < 0.05). miR-15a decreased and Cdc42 increased in the CD RE group compared to the CD AC group (P < 0.05). miR-15a was positively correlated with the Pediatric Crohn’s disease Activity Index (PCDAI) (P = 0.006), while Cdc42 was negatively correlated with PCDAI (P = 0.0008). Finally, miR-15a expression negatively correlated with Cdc42 in pediatric IBD patients (P = 0.0045).

CONCLUSION

MiR-15a negatively regulates epithelial junctions through Cdc42 in Caco-2 cells and pediatric IBD patients.

[Clinical study on relationship of CD62p, CD63 and TSP to the qi-stagnation induced blood-stasis syndrome and qi-deficiency induced blood-stasis syndrome in aged patients]

OBJECTIVE

To observe the relationship of platelet activation to the Qi-stagnation induced blood-stasis (QSBS) or Qi-deficiency induced blood-stasis (QDBS) syndrome.

METHODS

Expressions of platelet activating molecules, including alpha-granule membrane glycoprotein (CD62p), lysosomal integral membrane protein (CD63) and thrombospondin (TSP), in patients with QSBS and QDBS were determined quantitatively with flow-cytometry and specific monoclonal antibody against activated platelet. And platelet aggregation was tested simultaneously.

RESULTS

CD62p, CD63 and TSP expressions in Blood-Stasis patients, both QSBS and QDBS, were higher than those in the normal control significantly (all P < 0.01); all the three expressions were higher in QSBS group than those in QDBS group (all P < 0.01), Positive correlation was shown between CD62p and CD63 (r = 0.740, P < 0.01), CD62p and TSP (r = 0.744, P < 0.01), TSP and CD63 (r = 0.635, P < 0.01), and between CD62p and ADP induced platelet aggregation (r = 0.715, P < 0.01).

CONCLUSION

Platelet activation was involved in the pathogenesis and development of Blood-Stasis Syndrome, especially closely related with the QSBS Syndrome.