Toward Microsurgical Correction of Cleft Lip Ex Utero through Restoration of Craniofacial Developmental Programs

Abstract

Background Cleft Lip with or without Palate (CL/P) is present in approximately 1 in 500–700 live births, representing the most common congenital craniofacial anomaly. Previously, we developed a unique murine model with compound Pbx deficiency that exhibits fully penetrant CL/P. To investigate the possibility of tissue repair at an early gestational stage, we designed a minimally invasive surgical approach suitable for intrauterine repair using Wnt9b-soaked collagen microspheres to restore craniofacial developmental programs for cleft correction. Methods Collagen microspheres with diameters ranging from 20–50 microns were fabricated to serve as a delivery vehicle for Wnt9b. At gestational day 11.5, wild type and Pbx-deficient murine embryos were isolated. Microspheres soaked in murine purified Wnt9b protein were microsurgically implanted at the midface λ junction. Embryos were cultured in a 37°C modified Whole Embryo Culture (WEC) system. Results Targeted release of Wnt9b resulted in augmented Wnt expression at the λ junction. Microsurgical implantation of Wnt9b-soaked microspheres resulted in cleft correction in 27.1% of the Pbx-deficient embryos. The difference in the ratio of the areas of clefting between implanted and non-implanted embryos was significant (p<0.05). Conclusion Ex utero correction of CL/P in our murine model via microsurgical intervention and targeted delivery of Wnt proteins is an innovative and promising strategy. Although further refinement and optimization of this technique will be required to improve efficacy, we believe that this approach will open new avenues towards unconventional prenatal interventions for patients with CL/P, as well as provide future approaches for prenatal repair of other congenital head and neck disorders.

‘Building a perfect body’: control of vertebrate organogenesis by PBX-dependent regulatory networks

“…Pertubation of this PBX-dependent circuit results in concomitant loss of apoptosis and EMT at the λ with ensuing CL/P. By reactivation of WNT Can in the cephalic epithelium of compound Pbx mutant embryos, we restored apoptosis and rescued CL/P in all mutants analyzed, opening new avenues for in utero tissue repair of this birth defect Dong et al 2017;Losa et al 2018). As PBX1 was identified as a driver of EMT in lung and liver cancer (Risolino et al 2014;Kodama et al 2016), this research highlights PBX-dependent interconnected cellular behaviors in midface morphogenesis and tumor metastasis.…”

Identification of differentially expressed proteins involved in fetal scarless wound healing using a rat model of cleft lip

“…The mRNA levels of the differentially expressed molecules were assessed using reverse transcription-quantitative (RT-q) PCR, as previously described ( 19 ). Differentially expressed levels of proteins were detected by label-free quantification PRM as previously described ( 17 ).…”