Assessing the association between hypoxia during craniofacial development and oral clefts

Abstract

ObjectivesTo evaluate the association between hypoxia during embryo development and oral clefts in an animal model, and to evaluate the association between polymorphisms in the HIF-1A gene with oral clefts in human families.Material and MethodsThe study with the animal model used zebrafish embryos at 8 hours post-fertilization submitted to 30% and 50% hypoxia for 24 hours. At 5 days post-fertilization, the larvae were fixed. The cartilage structures were stained to evaluate craniofacial phenotypes. The family-based association study included 148 Brazilian nuclear families with oral clefts. The association between the genetic polymorphisms rs2301113 and rs2057482 in HIF-1A with oral clefts was tested. We used real time PCR genotyping approach. ANOVA with Tukey's post-test was used to compare means. The transmission/disequilibrium test was used to analyze the distortion of the inheritance of alleles from parents to their affected offspring.ResultsFor the hypoxic animal model, the anterior portion of the ethmoid plate presented a gap in the anterior edge, forming a cleft. The hypoxia level was associated with the severity of the phenotype (p<0.0001). For the families, there was no under-transmitted allele among the affected progeny (p>0.05).ConclusionHypoxia is involved in the oral cleft etiology, however, polymorphisms in HIF-1A are not associated with oral clefts in humans.

Expression Analysis of FGF/FGFR and FOX Family Proteins in Mucosal Tissue Obtained from Orofacial Cleft-Affected Children

“…Additionally, hypoxia has been associated with the pathogenesis of cleft lip and palate; however, the exact mechanism is not yet known. Recently, polymorphisms of the HIF-1A (hypoxia inducible factor 1A) gene were ruled out as a cause of clefting [ 60 ]. We propose that hypoxia-induced clefting is probably rather related more directly with the FGF/FGFR signaling pathway (this needs further validation).…”

Zebrafish Models of Craniofacial Malformations: Interactions of Environmental Factors

“…In studies on the effects of maternal smoking on development, zebrafish were traditionally used as a model to examine effects of single abundant compounds of cigarette smoke. Craniofacial malformations are consistently reported in zebrafish studies on smoke compounds such as PAHs, carbon monoxide (hypoxia) and nicotine (Billiard et al, 2006;Parker and Connaughton, 2007;Geier et al, 2018;Kuchler et al, 2018). Specifically, clefts in the ethmoid plate were observed when zebrafish are exposed to hypoxic conditions during early development.…”

“… (A) Wildtype ethmoid plate with associated stacking of chondrocytes. (B) Redrawn examples of ethmoid plate defects observed in zebrafish environmental factor exposure studies ( Kuchler et al, 2018 ; Liu et al, 2020 ) (Methotrexate 100 μM, Dexamethasone 200 μM, retinoic acid 5 nM and hypoxia). A broad phenotypic range of ethmoid plate defects is observed, indicating that development of the ethmoid plate is affected variously by different compounds.…”

“…Specifically, clefts in the ethmoid plate were observed when zebrafish are exposed to hypoxic conditions during early development. These clefts increased in severity as oxygen levels were reduced ( Kuchler et al, 2018 ). Although single-factor investigations are interesting from a fundamental standpoint, they do not provide clinically relevant insights on the effects of maternal smoking on development, because the combined teratogenic effects of smoke compounds may be additive.…”

miR‑16‑2‑3p inhibits cell proliferation and migration and induces apoptosis by targeting PDPK1 in�maxillary primordium mesenchymal cells

“…Nonsyndromic cleft lip (NSCL) is one of most common birth defects that negatively affects facial appearance and lip function (1-3). Multiple factors have been demonstrated to contribute to the etiology of NSCL, including geographical distribution, ethnic background, economic status, genetics and environmental factors (4,5). Surgery is the primary treatment for NSCL (6-10), but identifying potential regulators of the underlying mechanisms of NSCL may aid in the development of novel treatment strategies.…”