The ciliary proteins Meckelin and Jouberin are required for retinoic acid-dependent neural differentiation of mouse embryonic stem cells

How Coronavirus Disease 2019 Changed Dermatology Practice in 1 Year Around the World: Perspectives from 11 Countries

Coronavirus disease 2019 (COVID-19) brought the world to its knees. As each nation grappled with launching an effective response while simultaneously minimizing repercussions on health care systems, economies, and societies, the medical and scientific landscape shifted forever. In particular, COVID-19 has challenged and transformed the field of dermatology and the way we practice. In this article, dermatologists from 11 countries share insights gained from local experience. These global perspectives will help provide a better framework for delivering quality dermatologic care and understanding how the field has evolved during this medical crisis.

Dyslexia Candidate Gene and Ciliary Gene Expression Dynamics During Human Neuronal Differentiation

Developmental dyslexia (DD) is a neurodevelopmental condition with complex genetic mechanisms. A number of candidate genes have been identified, some of which are linked to neuronal development and migration and to ciliary functions. However, expression and regulation of these genes in human brain development and neuronal differentiation remain uncharted. Here, we used human long-term self-renewing neuroepithelial stem (lt-NES, here termed NES) cells derived from human induced pluripotent stem cells to study neuronal differentiation in vitro. We characterized gene expression changes during differentiation by using RNA sequencing and validated dynamics for selected genes by qRT-PCR. Interestingly, we found that genes related to cilia were significantly enriched among upregulated genes during differentiation, including genes linked to ciliopathies with neurodevelopmental phenotypes. We confirmed the presence of primary cilia throughout neuronal differentiation. Focusing on dyslexia candidate genes, 33 out of 50 DD candidate genes were detected in NES cells by RNA sequencing, and seven candidate genes were upregulated during differentiation to neurons, including DYX1C1 (DNAAF4), a highly replicated DD candidate gene. Our results suggest a role of ciliary genes in differentiating neuronal cells and show that NES cells provide a relevant human neuronal model to study ciliary and DD candidate genes.

Review of Ocular Manifestations of Joubert Syndrome

Joubert syndrome is a group of rare disorders that stem from defects in a sensory organelle, the primary cilia. Affected patients often present with disorders involving multiple organ systems, including the brain, eyes, and kidneys. Common symptoms include breathing abnormalities, mental developmental delays, loss of voluntary muscle coordination, and abnormal eye movements, with a diagnostic “molar tooth” sign observed by magnetic resonance imaging (MRI) of the midbrain. We reviewed the ocular phenotypes that can be found in patients with Joubert syndrome. Ocular motor apraxia is the most frequent (80% of patients), followed by strabismus (74%) and nystagmus (72%). A minority of patients also present with ptosis (43%), chorioretinal coloboma (30%), and optic nerve atrophy (22%). Although mutations in 34 genes have been found to be associated with Joubert syndrome, retinal degeneration has been reported in only 38% of patients. Mutations in AHI1 and CEP290, genes critical to primary cilia function, have been linked to retinal degeneration. In conclusion, Joubert syndrome is a rare pleiotropic group of disorders with variable ocular presentations.

The Multifaceted Roles of Primary Cilia in the Regulation of Stem Cell Properties and Functions

Stem cells are a unique class of cells that are capable of self-renewal and differentiation into multiple lineages. An increasing number of studies have suggested that both embryonic and adult stem cells possess primary cilia, antenna-like structures protruding from cell surfaces that are critical for sensing and transducing environmental cues. The primary cilium appears to regulate stem cells in multiple aspects, such as lineage specification and stemness maintenance. Understanding the role of primary cilia in the control of stem cell behavior could lead to the identification of new targets for regenerative therapies. Here, we discuss recent studies investigating the diverse roles of primary cilia in the regulation of stem cell properties and functions. We also propose potential new avenues for exploration in this promising field. J. Cell. Physiol. 232: 935-938, 2017. © 2016 Wiley Periodicals, Inc.