Department of Molecular, Cell and Cancer Biology, Program in Molecular Medicine, University of Massachusetts Medical School, 364 Plantation Street, Worcester, MA, 01605, USA.
Adv Sci (Weinh). 2022 Jan;9(2):e2102949. doi: 10.1002/advs.202102949. Epub 2021 Nov 7.
Adipose thermogenesis plays a pivotal role in whole-body metabolic homeostasis. Although transcriptional mechanisms that promote thermogenesis are extensively studied, the negative regulatory network is still poorly understood. Here, a Krüppel-associated box (KRAB) domain-containing zinc finger protein, ZFP961, as a potent repressor of the thermogenic program is identified. ZFP961 expression is induced by cold and β3-adrenergic agonist in adipose tissue. ZFP961 represses brown fat-selective gene expression and mitochondrial respiration without any effect on general adipogenesis in cultured adipocytes. Adipose-specific knockdown and overexpression of ZFP961 produce remarkable and opposite phenotypes of white fat remodeling. ZFP961 knockout mice display robust inguinal white adipose tissue browning, which is abolished by reexpression of full-length ZFP961, but not by KRAB domain-deleted ZFP961 mutant. ZFP961-deficient mice are cold tolerant and resistant to high-fat diet-induced obesity, hyperglycemia, and hepatic steatosis. ZFP961 suppresses thermogenic gene expression by directly interacting with PPARα and blocking its transcriptional activity, which can be completely negated by the PPARα agonist. The findings uncover ZFP961 as a critical physiological brake that limits adipose thermogenesis and provides insights into the regulatory mechanisms that maintain energy balance and tissue homeostasis.
脂肪组织的产热对于维持全身代谢稳态起着关键作用。虽然促进产热的转录机制已得到广泛研究,但对于负调控网络仍知之甚少。本研究中鉴定了一个富含 Krüppel 相关盒(KRAB)结构域的锌指蛋白 ZFP961,它是产热程序的有效抑制剂。ZFP961 的表达可被寒冷和β3-肾上腺素能激动剂诱导。在培养的脂肪细胞中,ZFP961 抑制棕色脂肪选择性基因表达和线粒体呼吸,但对一般脂肪生成没有任何影响。脂肪组织特异性敲低和过表达 ZFP961 会产生显著的白色脂肪重塑表型,且表现为相反的作用。ZFP961 敲除小鼠腹股沟白色脂肪组织出现强烈的褐色化,这种褐色化可被全长 ZFP961 的重新表达所消除,但不能被缺失 KRAB 结构域的 ZFP961 突变体所消除。ZFP961 缺陷型小鼠对寒冷耐受,并且对高脂肪饮食诱导的肥胖、高血糖和肝脂肪变性有抗性。ZFP961 通过与 PPARα 直接相互作用并阻断其转录活性来抑制产热基因表达,这种抑制作用可被 PPARα 激动剂完全消除。这些发现揭示了 ZFP961 作为一种关键的生理制动器,限制了脂肪组织的产热,并为维持能量平衡和组织稳态的调节机制提供了新的见解。