CEP41-mediated ciliary tubulin glutamylation drives angiogenesis through AURKA-dependent deciliation.

The endothelial cilium is a microtubule-based organelle responsible for blood flow-induced mechanosensation and signal transduction during angiogenesis. The precise function and mechanisms by which ciliary mechanosensation occurs, however, are poorly understood. Although posttranslational modifications (PTMs) of cytoplasmic tubulin are known to be important in angiogenesis, the specific roles of ciliary tubulin PTMs play remain unclear. Here, we report that loss of centrosomal protein 41 (CEP41) results in vascular impairment in human cell lines and zebrafish, implying a previously unknown pro-angiogenic role for CEP41. We show that proper control of tubulin glutamylation by CEP41 is necessary for cilia disassembly and that is involved in endothelial cell (EC) dynamics such as migration and tubulogenesis. We show that in ECs responding to shear stress or hypoxia, CEP41 activates Aurora kinase A (AURKA) and upregulates expression of VEGFA and VEGFR2 through ciliary tubulin glutamylation, as well as leads to the deciliation. We further show that in hypoxia-induced angiogenesis, CEP41 is responsible for the activation of HIF1α to trigger the AURKA-VEGF pathway. Overall, our results suggest the CEP41-HIF1α-AURKA-VEGF axis as a key molecular mechanism of angiogenesis and demonstrate how important ciliary tubulin glutamylation is in mechanosense-responded EC dynamics.

Wharton's Jelly-Derived Mesenchymal Stem Cells with High Aurora Kinase A Expression Show Improved Proliferation, Migration, and Therapeutic Potential.

Mesenchymal stem cells (MSCs) are effective therapeutic agents that contribute to tissue repair and regeneration by secreting various factors. However, donor-dependent variations in MSC proliferation and therapeutic potentials result in variable production yields and clinical outcomes, thereby impeding MSC-based therapies. Hence, selection of MSCs with high proliferation and therapeutic potentials would be important for effective clinical application of MSCs. This study is aimed at identifying the upregulated genes in human Wharton's jelly-derived MSCs (WJ-MSCs) with high proliferation potential using mRNA sequencing. Aurora kinase A (AURKA) and dedicator of cytokinesis 2 (DOCK2) were selected as the upregulated genes, and their effects on proliferation, migration, and colony formation of the WJ-MSCs were verified using small interfering RNA (siRNA) techniques. mRNA expression levels of both the genes were positively correlated with the proliferation capacity of WJ-MSCs. Moreover, AURKA from human WJ-MSCs regulated the antiapoptotic effect of skeletal muscle cells by upregulating the chemokine (C motif) ligand (XCL1); this was further confirmed in the mdx mouse model. Taken together, the results indicated that AURKA and DOCK2 can be used as potential biomarkers for proliferation and migration of human WJ-MSCs. In particular, human WJ-MSCs with high expression of AURKA might have therapeutic efficacy against muscle diseases, such as Duchenne muscular dystrophy (DMD).

Wharton's Jelly-Derived Mesenchymal Stem Cells Reduce Fibrosis in a Mouse Model of Duchenne Muscular Dystrophy by Upregulating microRNA 499.

The aim of this study was to evaluate the therapeutic effects and mechanisms of Wharton's jelly-derived mesenchymal stem cells (WJ-MSCs) in an animal model of Duchenne muscular dystrophy (DMD). Mdx mice (3-5 months old) were administered five different doses of WJ-MSCs through their tail veins. A week after injection, grip strength measurements, creatine kinase (CK) assays, immunohistochemistry, and western blots were performed for comparison between healthy mice, mdx control mice, and WJ-MSC-injected mdx mice. WJ-MSCs exerted dose-dependent multisystem therapeutic effects in mdx mice, by decreasing CK, recovering normal behavior, regenerating muscle, and reducing apoptosis and fibrosis in skeletal muscle. We also confirmed that miR-499-5p is significantly downregulated in mdx mice, and that intravenous injection of WJ-MSCs enhanced its expression, leading to anti-fibrotic effects via targeting TGFßR 1 and 3. Thus, WJ-MSCs may represent novel allogeneic "off-the-shelf" cellular products for the treatment of DMD and possibly other muscle disorders.

Family-based exome sequencing and case-control analysis implicate CEP41 as an ASD gene.

Autism Spectrum Disorder (ASD) is a complex neurodevelopmental disorder with a strong genetic component. Although next-generation sequencing (NGS) technologies have been successfully applied to gene identification in de novo ASD, the genetic architecture of familial ASD remains largely unexplored. Our approach, which leverages the high specificity and sensitivity of NGS technology, has focused on rare variants in familial autism. We used NGS exome sequencing in 26 families with distantly related affected individuals to identify genes with private gene disrupting and missense variants of interest (VOI). We found that the genes carrying VOIs were enriched for biological processes related to cell projection organization and neuron development, which is consistent with the neurodevelopmental hypothesis of ASD. For a subset of genes carrying VOIs, we then used targeted NGS sequencing and gene-based variant burden case-control analysis to test for association with ASD. Missense variants in one gene, CEP41, associated significantly with ASD (p = 6.185e-05). Homozygous gene-disrupting variants in CEP41 were initially found to be responsible for recessive Joubert syndrome. Using a zebrafish model, we evaluated the mechanism by which the CEP41 variants might contribute to ASD. We found that CEP41 missense variants affect development of the axonal tract, cranial neural crest migration and social behavior phenotype. Our work demonstrates the involvement of CEP41 heterozygous missense variants in ASD and that biological processes involved in cell projection organization and neuron development are enriched in ASD families we have studied.