China: Obstructive sleep apnea (OSA) disturbs the Hifα/Pparα/NF-κB signaling axis compromising lacrimal gland structure and function resulting in dry eye, finds a recent study in Investigative Ophthalmology & Visual Science. The findings imply that a therapeutic approach targeting the Hifα/Pparα/NF-κB pathway may be helpful in preserving the function of the lacrimal gland and reducing dry eye symptoms exacerbated by OSA.
Shaopan Wang, Xiamen University, Xiamen, Fujian, China, and colleagues conducted the study with the objective to determine the effect of obstructive sleep apnea syndrome (OSA) on lacrimal gland function and its mechanism.
For this purpose, male mice aged seven to eight weeks were housed in cages with cyclic intermittent hypoxia to mimic OSA, and the control group was kept in a normal environment. Cornea changes were assessed using slit-lamp observation, fluorescein staining, and corneal sensitivity detection.
Phenol red cotton thread detected tear secretion, and the pathological changes of the lacrimal gland were observed by hematoxylin and eosin staining, oil red O staining, cholesterol and triglyceride kits, immunofluorescence staining, immunohistochemical staining, real-time polymerase chain reaction, transmission electron microscopy, and Western blot.
The findings of the study were as follows:
Studies revealed a decreased tear secretion, corneal epithelial
defects, and corneal hypersensitivity.
Myoepithelial cell damage, abnormal lipid accumulation, reduced
cell proliferation, increased apoptosis, and inflammatory cell infiltration in
the lacrimal gland were also seen.
Hifα and NF-κB signaling pathways, moreover, were activated, while Pparα was downregulated, in the
lacrimal glands of OSA mice.
Fenofibrate treatment significantly alleviated pathological
changes of the lacrimal gland induced by OSA.
“Our study for the first time confirmed a causative relationship between OSA and lacrimal gland dysfunction and pointed out a potential clinical treatment for OSA-related dry eye,” the authors wrote in their study.
“Our study suggests that OSA is a causative factor for dry eye disease and reveals a mechanism by which OSA could lead to abnormal lacrimal gland lipid metabolism through the Hif-Pparα signaling pathway, ultimately triggering manifestations of dry eye.”
Shaopan Wang, Xin He, Qingmin Li, Yuhan Zhang, Jiaoyue Hu, Rongrong Zong, Jingyi Zhuang, Andrew J. Quantock, Yingying Gao, Wei Li, Zuguo Liu; Obstructive Sleep Apnea Affects Lacrimal Gland Function. Invest. Ophthalmol. Vis. Sci. 2022;63(3):3. doi: https://doi.org/10.1167/iovs.63.3.3.