Diurnal rhythm-modulated transcriptome analysis of meibomian gland in hyperlipidemic mice using RNA sequencing

Hyperlipidemia can induce the dysfunction of meibomian gland (MG) in mice, which may be affected by circadian rhythm. However, the underlying mechanism remains unclear. In this study, we exposed the hyperlipidemic mice model induced by four months feeding of high-fat diet to the regular light-dark cycles for two weeks. Then, phenotypic observation and RNA-seq of MG in experimental mice were performed to investigate the effect and transcriptional changes of hyperlipidemia and circadian rhythm on MG dysfunction. As a result, several significantly expressed genes and enriched pathways were identified to be associated with MG dysfunction in hyperlipidemic mice under circadian rhythms. High fat diet can not only bring hyperlipidemia, but also cause meibomian gland dysfunction, which is affected by rhythm genes. These data can provide us with a deeper understanding of the outcomes of MG altered by daily nutritional challenge. Overall design: 6 to 8-week-old male C57BL/6 mice (purchased from Charles River Laboratories, Beijing, China) were housed under a 12-hour light/12-hour dark (LD) cycle. After adaptively fed for 1 week, the mice were randomly divided into two groups. The mice in the treatment group (the HF group) were fed with a high-fat diet (D12492, Xietong Pharmaceutical Bio-engineering Co. Ltd., Jiangsu, China; 60 kcal% fat) for 4 months, and the age-matched mice in the control group (the CT group,) were fed with a standard-fat diet (1010009, Xietong Pharmaceutical Bio-engineering Co. Ltd., Jiangsu, China; 10 kcal% fat) for 4 months. The mice in each group were sacrificed at different times (9 am, 3 pm, and 9 pm), the upper and lower eyelids were removed in whole to extract mRNA samples, and gene expression profiling was performed by high-throughput sequencing.