Sawai Megumi, Watanabe Keisuke, Tanaka Kana, Kinoshita Wataru, Otsuka Kento, Miyamoto Masatoshi, Sassa Takayuki, Kihara Akio
Laboratory of Biochemistry, Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Kita 12-jo, Nishi 6-chome, Kita-ku 060-0812, Japan.
Pharmaceutical Research Laboratories, Research and Development Headquarters, Lion Corporation, Odawara 256-0811, Japan.
iScience. 2021 Apr 26;24(5):102478. doi: 10.1016/j.isci.2021.102478. eCollection 2021 May 21.
A lipid layer consisting of meibum lipids exists in the tear film and functions in preventing dry eye disease. Although the meibum lipids include diverse lipid classes, the synthesis pathway and role of each class remain largely unknown. Here, we created single and double knockout (KO and DKO, respectively) mice for the two acyl-CoA wax alcohol acyltransferases ( and ) and investigated their dry eye phenotypes and meibum lipid composition. KO and DKO mice exhibited severe dry eye with meibomian gland dysfunction, whereas KO mice had mild dry eye. In these mice, specific meibum lipid classes were reduced: (-acyl)-ω-hydroxy fatty acids and type 1ω wax diesters in KO mice, wax monoesters and types 1ω and 2ω wax diesters in KO mice, and most of these in DKO mice. Our findings reveal that Awat1 and Awat2 show characteristic substrate specificity and together produce diverse meibum lipids.
泪膜中存在由睑脂构成的脂质层,其功能是预防干眼症。尽管睑脂包含多种脂质类别,但每种脂质类别的合成途径和作用仍大多未知。在此,我们构建了两种酰基辅酶A蜡醇酰基转移酶(分别为 和 )的单基因敲除和双基因敲除(分别为KO和DKO)小鼠,并研究了它们的干眼表型和睑脂组成。KO和DKO小鼠表现出严重干眼并伴有睑板腺功能障碍,而 KO小鼠有轻度干眼。在这些小鼠中,特定的睑脂类别减少: KO小鼠中(-酰基)-ω-羟基脂肪酸和1型ω蜡二酯减少, KO小鼠中蜡单酯以及1型和2型ω蜡二酯减少,而在DKO小鼠中这些脂质大多减少。我们的研究结果表明,Awat1和Awat2表现出特征性底物特异性,并共同产生多种睑脂。