Dysregulation of Rho GTPases in orofacial cleft patients-derived primary cells leads to impaired cell migration, a potential cause of cleft/lip palate development

A TAF11 variant contributes to non-syndromic cleft lip only through modulating neural crest cell migration

The NC_000006.12: g.34887814C>G variant in TAF11 was identified as a potential functional variant in a Chinese pedigree including two non-syndromic cleft lip only (NSCLO) cases. Applying Chromatin Immunoprecipitation (ChIP), Electrophoretic mobility shift and super-shift assays, we found that the mutant G allele recruited more STAT1 and STAT3, and increased the expression of TAF11. RNA sequencing, GO and KEGG pathway enrichment, ChIP and dual-luciferase reporter assays revealed that TAF11 downregulated CDH1 and CTNND1 in the cell adhesion pathway by binding to their promoter regions and inhibiting transcriptional activities. Alcian blue staining, time-lapse photography, whole-mount in situ hybridization, phospho-Histone H3 immunofluorescence and TUNEL assays indicated that TAF11 and taf11 overexpression (TAF11OE and taf11OE, respectively) contributed to disturbed migration of cranial neural crest cells and abnormal craniofacial development, as well as increased death and deformity rates in zebrafish. In conclusion, a functionally relevant TAF11 variant, affecting cell migration via modulating CDH1 and CTNND1, was associated with etiology of NSCLO.

Identification of novel genes regulating the development of the palate

The International Mouse Phenotyping Consortium (IMPC) has generated thousands of knockout mouse lines, many of which exhibit embryonic or perinatal lethality. Using micro-computed tomography (micro-CT), the IMPC has created and publicly released 3D image datasets of embryos from these lethal and subviable lines. In this study, we leveraged this dataset to screen homozygous null mutants for anomalies in secondary palate development. We analyzed optical sections from 2,987 embryos at embryonic days E15.5 and E18.5, representing 484 homozygous mutant lines. Our analysis identified 45 novel genes implicated in palatogenesis. Gene set enrichment analysis highlighted biological processes and pathways relevant to palate development and uncovered 18 genes jointly regulating the development of the eye and the palate. These findings present a valuable resource for further research, offer novel insights into the molecular mechanisms underlying palatogenesis, and provide important context for understanding the etiology of rare human congenital disorders involving simultaneous malformations of the palate and other organs, including the eyes, ears, kidneys, and lungs.

lncRNA MIR31HG Regulates Proliferation and Migration by Targeting Matrix Gla Protein in Nonsyndromic Cleft Lip With or Without Cleft Palate

Nonsyndromic cleft lip with or without cleft palate (NSCL/P) is a common craniofacial birth defect with complex etiologies. Recently, the dysregulation of long noncoding RNAs (lncRNAs) has been implicated in many developmental diseases, including NSCL/P. However, the functions and mechanisms of lncRNAs in NSCL/P have not been fully elucidated. In this study, we found that lncRNA MIR31HG in NSCL/P patients was significantly downregulated than that in healthy individuals (GSE42589, GSE183527). In addition, single nucleotide polymorphism rs58751040 in MIR31HG was nominally associated with NSCL/P susceptibility (odds ratio: 1.29, 95% confidence interval: 1.03-1.54, p = 4.93 × 10^-2) through a case-control study (504 NSCL/P cases and 455 controls). Luciferase activity assay showed that the C allele of rs58751040 revealed a decreased transcription activity of MIR31HG than the G allele. Moreover, knockdown of MIR31HG promoted cell proliferation and migration in human oral keratinocytes and human embryonic palate mesenchyme. Bioinformatic analysis and cellular studies suggested that MIR31HG may confer susceptibility to risk of NSCL/P through matrix Gla protein (MGP) signaling. In summary, we identified a novel lncRNA involved in the development of NSCL/P.

To Stick or Not to Stick: Adhesions in Orofacial Clefts

Morphogenesis requires a tight coordination between mechanical forces and biochemical signals to inform individual cellular behavior. For these developmental processes to happen correctly the organism requires precise spatial and temporal coordination of the adhesion, migration, growth, differentiation, and apoptosis of cells originating from the three key embryonic layers, namely the ectoderm, mesoderm, and endoderm. The cytoskeleton and its remodeling are essential to organize and amplify many of the signaling pathways required for proper morphogenesis. In particular, the interaction of the cell junctions with the cytoskeleton functions to amplify the behavior of individual cells into collective events that are critical for development. In this review we summarize the key morphogenic events that occur during the formation of the face and the palate, as well as the protein complexes required for cell-to-cell adhesions. We then integrate the current knowledge into a comprehensive review of how mutations in cell-to-cell adhesion genes lead to abnormal craniofacial development, with a particular focus on cleft lip with or without cleft palate.