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Updated: Jun 21, 2026

Two Peeling Methods for the Isolation of Photoreceptor Cell Compartments in the Mouse Retina for Protein Analysis
11:08

Two Peeling Methods for the Isolation of Photoreceptor Cell Compartments in the Mouse Retina for Protein Analysis

Published on: December 7, 2021

Interdependent roles of PKM2 in photoreceptors and RPE: implications for retinal degeneration

Ammaji Rajala1,2, Rahul Rajala3,4,5,6, Larissa J Trevino1,2

  • 1Department of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.

Cell Death & Disease
|June 19, 2026
PubMed

Insights

Pyruvate kinase M2 (PKM2) is crucial for mouse retinal structure and function. Its loss impairs energy production, leading to photoreceptor and retinal pigment epithelium degeneration, offering insights into macular degeneration.

Area of Science:

  • Cell Biology
  • Neuroscience
  • Biochemistry

Background:

  • Pyruvate kinase M2 (PKM2) is a key enzyme in glycolysis and a transcriptional co-activator.
  • Understanding PKM isoforms' roles in the retina is vital for comprehending retinal health and disease.

Purpose of the Study:

  • To investigate the developmental timing, cellular distribution, and physiological significance of PKM isoforms in the mouse retina.
  • To elucidate the role of PKM2 in maintaining retinal structure, function, and metabolic homeostasis.

Main Methods:

  • Conditional PKM2 deletion in mouse retinas, rods, and retinal pigment epithelium (RPE).
  • Analysis of glycolytic activity, ATP generation, and metabolic balance.
  • Assessment of RPE65 levels, visual cycle function, and cone opsin gradients.
  • Evaluation of retinal degeneration in Abca4 mutant mice with rod-specific PKM2 deletion.

Main Results:

  • PKM2 expression begins postnatally and is enriched in photoreceptors, while PKM1 is found in retinal ganglion cells.
  • PKM2 deletion severely impacts retinal structure and function, causing photoreceptor and RPE degeneration.
  • Loss of PKM2 disrupts glycolysis, reduces ATP, impairs the visual cycle, and affects cone organization.
  • Rod-specific PKM2 deletion exacerbates degeneration in Abca4 mutant mice.

Conclusions:

  • PKM2 is essential for retinal energy homeostasis, photoreceptor and RPE survival, and proper cone organization.
  • PKM2 plays a critical role in coordinating metabolism and cell survival within the retina.
  • These findings provide insights into mechanisms of retinal degeneration relevant to age-related macular degeneration.

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