Palmitic Acid Downregulates Thyroglobulin (Tg), Sodium Iodide Symporter (NIS), and Thyroperoxidase (TPO) in Human Primary Thyrocytes: A Potential Mechanism by Which Lipotoxicity Affects Thyroid?

Figure 4

Palmitic acid downregulates the activity of thyroglobulin (Tg), sodium iodide symporter (NIS), and thyroperoxidase (TPO) in human primary thyrocytes. (a) Secreted Tg levels in supernatants of cells stimulated with palmitic acid for 72 hours (). The Tg levels were normalized with corresponding protein amount. (b) The effects of palmitic acid stimulation on ¹³¹I uptake for 72 hours (n = 7). ¹³¹I uptake values were normalized with corresponding cell counts. (c) Extracellular TPO activity of the cells stimulated with palmitic acid for 72 hours (). Enzymatic activity values were normalized with corresponding protein amount. In all panels, representative data from 3 to 7 independent experiments are shown. All data are expressed as the mean ± standard deviation. and versus human primary thyrocytes without palmitic acid stimulation. The error bars represent the standard deviations. PA: palmitic acid; RFU: relative fluorescence unit.

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