Meibomian gland epithelial cells demonstrate enhanced reliance on glycolysis for energy metabolism and differentiation

Background Meibomian gland dysfunction is a leading cause of dry eye disease. Previous studies have established that the meibomian gland exists in a physiological hypoxic environment, with hypoxia-inducible factor 1α playing a regulatory role. However, the metabolic strategy of this gland remains unclear. This study aimed to test the hypothesis that glycolysis serves as an important metabolic pathway in meibomian gland epithelial cells in vivo and that these cells have an enhanced glycolytic phenotype during differentiation. Methods We combined clinical imaging, tissue analysis, and in vitro experiments to test our hypothesis. Results 18 F-fluorodeoxyglucose positron emission tomography/computed tomography revealed significantly higher glucose uptake in human meibomian glands than in the orbicularis oculi muscle and surrounding subcutaneous connective tissues outside the tarsal plate, indicating substantial glycolytic activity in vivo. Immunofluorescence staining confirmed strong expression of glycolytic markers, including hypoxia-inducible factor 1α, glucose transporter type 1, hexokinase 2, 6-phosphofructo-2-kinase/fructose−2,6-biphosphatase 3, and pyruvate kinase M2, and lactate dehydrogenase A, in both human and mouse meibomian gland tissues. In immortalized human meibomian gland epithelial cells, differentiation induced a metabolic shift favoring glycolysis with increased extracellular acidification rate, elevated lactate production, and upregulated glycolytic enzyme expression. Three-dimensional spheroid cultures further revealed state-dependent metabolic heterogeneity. Conclusion The findings indicate that meibomian gland epithelial cells have a highly glycolytic phenotype in vivo and markedly enhanced glycolytic dependence during differentiation. These support their specialized secretory functions and adaptation to hypoxic microenvironments.