Researchers at the Schepens Eye Research Institute have proven that low oxygen conditions promote the function of human MG epithelial cells and that human MGs exist in a relatively low oxygen environment. Their study also found that relative hypoxia significantly increased DNase II activity in meibomian gland (MG) cells and immortalized human meibomian gland epithelial cell terminal differentiation.

The researchers studied human and mouse eyelid segments and immortalized human MG epithelial cells. The studied the cell number, neutral lipid content, lysosome accumulation, expression of biomarker proteins and DNase II activity in the epithelial cells. Human and mouse MGs, but not the surrounding connective tissue, exist in a relatively hypoxic environment in vivo. Hypoxia does not influence MG epithelial cell numbers in basal or proliferating culture conditions but does stimulate the expression of SREBP-1 in differentiating MG epithelial cells. Researchers emphasized that optimal meibomian gland function is critically important for the health and well being of the ocular surface. 

Liu Y, Chen D, Chen X, et al. Hypoxia: a breath of fresh air for the meibomian gland. Ocul Surf. December 4, 2018. [Epub ahead of print].