Focus on the Eye
The editors of Laboratory Investigation and Modern Pathology present a variety of recent papers related to ocular pathology. These experimental and diagnostic studies cover congenital anomalies, corneal injury and repair, degenerative disease, and various malignancies.
Homeostasis of the corneal epithelium is critical in exerting a barrier function to noxious external stimuli. This study shows that that plakoglobin, a member of the catenin protein family, is essential to the maintenance of homeostasis of the corneal epithelium in mice. Corneal epithelium-specific deletion of the plakoglobin gene impairs tissue integrity against mechanical intervention and also suppresses wound healing without affecting cell proliferation.
Sensory nerve supports epithelial stem cell function in healing of corneal epithelium in mice: the role of trigeminal nerve transient receptor potential vanilloid 4
The trigeminal sensory nerve is critical for maintenance of corneal epithelial stem cells in the corneal limbus and is essential to the homeostasis of the tissue. TRPV4 signal mediated gene expression in the nerve drives expression of stem cell markers and nerve growth factor in the limbal stem cells as well as potentiates their proliferation.
Blockade of MDM2 with inactive Cas9 prevents epithelial to mesenchymal transition in retinal pigment epithelial cells
CRISPR/dCas9 blocks TGF-β2-induced mouse double minute 2 (MDM2) expression by targeting its second promoter, without affecting the basal expression. Epithelial to mesenchymal transition is blocked by MDM2 suppression in retinal pigment epithelial cells. In this way, CRIPSR/dCas9 is a promising novel therapy for proliferative vitreoretinopathy without interfering basal gene function.
Oculopharyngeal muscular dystrophy (OPMD) is a late-onset myopathy caused by the expansion of polyalanine in the PABPN1 gene. Abnormal accumulation of PABPN1 on the inner membrane of mitochondria was detected in mouse and cell models of OPMD. The localization of expanded PABPN1 in mitochondria may be associated with mitochondrial dysfunction.