Corneal epithelial cells upregulate macropinocytosis to engulf metabolically active axonal mitochondria released by injured axons

The Ocular Surface, Journal Year: 2025, Volume and Issue: 37, P. 173 - 188

Published: April 7, 2025

To determine the mechanisms used to internalize mitochondria by corneal epithelial cells after in vivo trephine injury and vitro cells. Male female mice were subjected euthanized immediately, 6, 24 hours injury. Macropinocytosis was quantified using 70 kD fluorescent dextran. Mitochondrial content assessed immunofluorescence metabolic activity Seahorse assay immediately 6 In experiments human limbal (HCLE) isolated performed assess mitochondrial transfer presence of gap junction inhibitor 18α-glycyrrhetinc acid macropincytosis ethylisopropylamiloride. Mitochondria accumulate within apical cell layers minutes also increases Oxygen Consumption Rates increase epithelium males females. Inhibiting junctions engulfment while inhibiting macropinocytosis prevents vitro. Molecules released injured severed axons induce An oxygen consumption rate indicates that axonal can evade lysosomal degradation for at least hours. studies labeled unlabeled control mechanically stressed confirm involvement free vesicle bound

Language: Английский

Mechanisms Regulating Mitochondrial Transfer in Human Corneal Epithelial Cells

Investigative Ophthalmology & Visual Science, Journal Year: 2024, Volume and Issue: 65(13), P. 10 - 10

Published: Nov. 6, 2024

Purpose: The intraepithelial corneal nerves (ICNs) innervating the cornea are essential to epithelial cell homeostasis. Rho-associated kinase (ROCK) inhibitors (RIs) have been reported play roles in neuron survival after injury and mitochondrial transfer between cells. In this study, mechanisms human limbal (HCLE) cells use control intercellular assessed. Methods: Mitotracker AAV1 mitotag eGFPmCherry were used allow us study HCLE neurons co-cultures cultures. A assay was developed using quantify impact of stress inhibition phagocytosis, gap junctions, ROCK on transfer, adhesion, migration, matrix deposition, content. Results: Bidirectional occurs neurons. Mitochondrial among is inhibited when junction function reduced enhanced by acid either phagocytosis or ROCK. Media conditioned RI-treated stimulates adhesion transfer. Conclusions: Maximal takes place junctions functional, inhibited, stressed low pH media. Treatments that reduce content increase causes release mitochondria substrates where they can be engulfed migrating growing axons their growth cones.

Language: Английский