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Ritter ML, Wagner VA, Balapattabi K, Opichka MA, Lu KT, Wackman KK, Reho JJ, Keen HL, Kwitek AE, Morselli LL, Geurts AM, Sigmund CD, Grobe JL. Krüppel-like factor 4 in transcriptional control of the three unique isoforms of Agouti-related peptide in mice. Physiol Genomics 2024; 56:265-275. [PMID: 38145289 PMCID: PMC10866620 DOI: 10.1152/physiolgenomics.00042.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 11/15/2023] [Accepted: 12/21/2023] [Indexed: 12/26/2023] Open
Abstract
Agouti-related peptide (AgRP/Agrp) within the hypothalamic arcuate nucleus (ARC) contributes to the control of energy balance, and dysregulated Agrp may contribute to metabolic adaptation during prolonged obesity. In mice, three isoforms of Agrp are encoded via distinct first exons. Agrp-A (ENSMUST00000005849.11) contributed 95% of total Agrp in mouse ARC, whereas Agrp-B (ENSMUST00000194654.2) dominated in placenta (73%). Conditional deletion of Klf4 from Agrp-expressing cells (Klf4Agrp-KO mice) reduced Agrp mRNA and increased energy expenditure but had no effects on food intake or the relative abundance of Agrp isoforms in the ARC. Chronic high-fat diet feeding masked these effects of Klf4 deletion, highlighting the context-dependent contribution of KLF4 to Agrp control. In the GT1-7 mouse hypothalamic cell culture model, which expresses all three isoforms of Agrp (including Agrp-C, ENSMUST00000194091.6), inhibition of extracellular signal-regulated kinase (ERK) simultaneously increased KLF4 binding to the Agrp promoter and stimulated Agrp expression. In addition, siRNA-mediated knockdown of Klf4 reduced expression of Agrp. We conclude that the expression of individual isoforms of Agrp in the mouse is dependent upon cell type and that KLF4 directly promotes the transcription of Agrp via a mechanism that is superseded during obesity.NEW & NOTEWORTHY In mice, three distinct isoforms of Agouti-related peptide are encoded via distinct first exons. In the arcuate nucleus of the hypothalamus, Krüppel-like factor 4 stimulates transcription of the dominant isoform in lean mice, but this mechanism is altered during diet-induced obesity.
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Affiliation(s)
- McKenzie L Ritter
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Valerie A Wagner
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
- Genetics Graduate Program, University of Iowa, Iowa City, Iowa, United States
| | - Kirthikaa Balapattabi
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Megan A Opichka
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Ko-Ting Lu
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Kelsey K Wackman
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - John J Reho
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
- Comprehensive Rodent Metabolic Phenotyping Core, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Henry L Keen
- Bioinformatics Division, Institute of Human Genetics, University of Iowa, Iowa City, Iowa, United States
| | - Anne E Kwitek
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
- Department of Biomedical Engineering, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
- Cardiovascular Center, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
- Linda T. and John A. Mellowes Center for Genomic Sciences and Precision Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Lisa L Morselli
- Cardiovascular Center, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
- Division of Endocrinology and Molecular Medicine, Department of Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Aron M Geurts
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
- Cardiovascular Center, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
- Linda T. and John A. Mellowes Center for Genomic Sciences and Precision Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Curt D Sigmund
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
- Cardiovascular Center, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
- Neuroscience Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Justin L Grobe
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
- Comprehensive Rodent Metabolic Phenotyping Core, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
- Department of Biomedical Engineering, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
- Cardiovascular Center, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
- Neuroscience Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
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