Department of Chemical Pathology, University of the Witwatersrand Faculty of Health Sciences, National Health Laboratory Service, School of Pathology, Johannesburg, South Africa.
Department of Chemical Pathology, University of the Witwatersrand Faculty of Health Sciences, National Health Laboratory Service, School of Pathology, Johannesburg, South Africa.
Ann Anat. 2020 Jan;227:151420. doi: 10.1016/j.aanat.2019.151420. Epub 2019 Sep 26.
Cholesterol esters (CEs) accumulate in the cells of the adrenal cortex and are used for the synthesis of steroid hormones. The full molecular pathways involved in mediating the accumulation of CEs within the adrenal cortex are yet to be elucidated. Tissue non-specific alkaline phosphatase (TNAP) is needed for intracellular lipid accumulation of triglycerides in adipocytes and is also expressed in the cortical cells of the adrenal gland. Therefore we aimed to determine if TNAP is needed for the accumulation of CEs within the murine Y1 adrenal cortex cell line.
Y1 cells were induced to accumulate lipids. Lipid accumulation and TNAP activity and expression were determined throughout intracellular lipid accumulation. The location of TNAP within the cell was determined through immunohistochemical analysis. Lipid accumulation in the cells was associated with a rise in TNAP activity and TNAP was localised to lipid droplets within the Y1 cells. Inhibition of TNAP with a specific inhibitor (levamisole) resulted in the cessation of CE accumulation.
These data demonstrate that TNAP plays a role in the control of lipid accumulation in this adrenal cortex cell line. Therefore, in both triglyceride and CE storing cell types TNAP would seem to be essential for intra-cellular lipid storage.
胆固醇酯（CEs）在肾上腺皮质细胞中积累，并用于合成类固醇激素。介导肾上腺皮质中 CE 积累的完整分子途径尚未阐明。组织非特异性碱性磷酸酶（TNAP）对于脂肪细胞中甘油三酯的细胞内脂质积累是必需的，并且在肾上腺皮质细胞中也有表达。因此，我们旨在确定 TNAP 是否需要在 Y1 肾上腺皮质细胞系中积累 CE。
诱导 Y1 细胞积累脂质。在细胞内脂质积累过程中，测定脂质积累和 TNAP 活性和表达。通过免疫组织化学分析确定 TNAP 在细胞内的位置。细胞内脂质的积累与 TNAP 活性的升高相关，并且 TNAP 定位于 Y1 细胞内的脂滴中。用特异性抑制剂（左旋咪唑）抑制 TNAP 会导致 CE 积累停止。
这些数据表明，TNAP 在控制该肾上腺皮质细胞系中的脂质积累中发挥作用。因此，在甘油三酯和 CE 储存细胞类型中，TNAP 似乎对细胞内脂质储存至关重要。
