Connexin 50 Regulates Surface Ball-and-Socket Structures and Fiber Cell Organization

Area of Science:

• Ophthalmology
• Cell Biology
• Developmental Biology

Background:

• The function of gap junction protein connexin 50 (Cx50) in lens development is not fully understood.
• Cx50 knockout lenses exhibit reduced epithelial cell proliferation and abnormal fiber cell denucleation.

Purpose of the Study:

• To investigate the cellular mechanisms underlying defects in connexin 50 knockout (Cx50 KO) lenses.
• To elucidate the role of Cx50 in lens fiber cell organization and morphology.

Main Methods:

• Immunofluorescent staining and confocal microscopy were used to visualize fiber cell morphology.
• Subcellular distribution of lens membrane and cytoskeleton proteins was analyzed in wild-type and Cx50 KO mice.

Main Results:

• Cx50 KO lenses showed abnormal fiber cell packing, reduced F-actin at tricellular vertices, and disrupted ball-and-socket (BS) structures.
• Cx46 gap junction plaques were detected in cortical fibers, with altered distributions of beta-dystroglycan and ZO-1 proteins.

Conclusions:

• Connexin 50 gap junctions are essential for BS structure maturation and cortical fiber cell organization.
• Cx50-based gap junctions likely stabilize BS structures by interacting with membrane/cytoskeletal proteins.
• Loss of Cx50 leads to BS disruption and altered F-actin, contributing to small lens and cataract phenotypes.