Qiongming Liu1, Junjie Yu2, Liheng Wang2, Yuliang Tang3, Quan Zhou4, Shuhui Ji4, Yi Wang5, Luis Santos6, Rebecca A Haeusler7, Jianwen Que8, Prashant Rajbhandari6, Xiaoguang Lei3, Luca Valenti9, Utpal B Pajvani10, Jun Qin11, Li Qiang12. 1. Naomi Berrie Diabetes Center, Department of Pathology and Cell Biology, College of Physicians and Surgeons, Columbia University, New York, 10032, USA; State Key Laboratory of Proteomics, Beijing Proteome Research Center, Beijing Institute of Lifeomics, National Center for Protein Sciences (The PHOENIX Center at Beijing), Beijing 102206, China. 2. Naomi Berrie Diabetes Center, Department of Medicine, College of Physicians and Surgeons, Columbia University, New York, New York, 10032, USA. 3. Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, Department of Chemical Biology, College of Chemistry and Molecular Engineering, Synthetic and Functional Biomolecules Center, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China. 4. State Key Laboratory of Proteomics, Beijing Proteome Research Center, Beijing Institute of Lifeomics, National Center for Protein Sciences (The PHOENIX Center at Beijing), Beijing 102206, China. 5. Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas, 77030, USA. 6. Diabetes, Obesity, and Metabolism Institute, Icahn School of Medicine at Mount Sinai, New York, United States. 7. Naomi Berrie Diabetes Center, Department of Pathology and Cell Biology, College of Physicians and Surgeons, Columbia University, New York, 10032, USA. 8. Columbia Center for Human Development and Department of Medicine, Columbia University, New York, NY 10032. 9. Department of Pathophysiology and Transplantation, Università degli Studi Milano, and Internal Medicine and Metabolic Diseases, Fondazione IRCCS Ca' Granda Ospedale Policlinico, Milan, Italy. 10. Naomi Berrie Diabetes Center, Department of Medicine, College of Physicians and Surgeons, Columbia University, New York, New York, 10032, USA. Electronic address: up2104@cumc.columbia.edu. 11. State Key Laboratory of Proteomics, Beijing Proteome Research Center, Beijing Institute of Lifeomics, National Center for Protein Sciences (The PHOENIX Center at Beijing), Beijing 102206, China; Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas, 77030, USA. Electronic address: jqin@bcm.edu. 12. Naomi Berrie Diabetes Center, Department of Pathology and Cell Biology, College of Physicians and Surgeons, Columbia University, New York, 10032, USA. Electronic address: LQ2123@cumc.columbia.edu.
Abstract
BACKGROUND & AIMS: Obesity is a well-established risk factor for type 2 diabetes (T2D) and non-alcoholic steatohepatitis (NASH), but the underlying mechanisms remain incompletely understood. Herein, we aimed to identify novel pathogenic factors (and possible therapeutic targets) underlying metabolic dysfunction in the liver. METHODS: We applied a tandem quantitative proteomics strategy to enrich and identify transcription factors (TFs) induced in the obese liver. We used flow cytometry of liver cells to analyze the source of the induced TFs. We employed conditional knockout mice, shRNA, and small-molecule inhibitors to test the metabolic consequences of the induction of identified TFs. Finally, we validated mouse data in patient liver biopsies. RESULTS: We identified PU.1/SPI1, the master hematopoietic regulator, as one of the most upregulated TFs in livers from diet-induced obese (DIO) and genetically obese (db/db) mice. Targeting PU.1 in the whole liver, but not hepatocytes alone, significantly improved glucose homeostasis and suppressed liver inflammation. Consistently, treatment with the PU.1 inhibitor DB1976 markedly reduced inflammation and improved glucose homeostasis and dyslipidemia in DIO mice, and strongly suppressed glucose intolerance, liver steatosis, inflammation, and fibrosis in a dietary NASH mouse model. Furthermore, hepatic PU.1 expression was positively correlated with insulin resistance and inflammation in liver biopsies from patients. CONCLUSIONS: These data suggest that the elevated hematopoietic factor PU.1 promotes liver metabolic dysfunction, and may be a useful therapeutic target for obesity, insulin resistance/T2D, and NASH. LAY SUMMARY: Expression of the immune regulator PU.1 is increased in livers of obese mice and people. Blocking PU.1 improved glucose homeostasis, and reduced liver steatosis, inflammation and fibrosis in mouse models of non-alcoholic steatohepatitis. Inhibition of PU.1 is thus a potential therapeutic strategy for treating obesity-associated liver dysfunction and metabolic diseases.
BACKGROUND & AIMS:Obesity is a well-established risk factor for type 2 diabetes (T2D) and non-alcoholic steatohepatitis (NASH), but the underlying mechanisms remain incompletely understood. Herein, we aimed to identify novel pathogenic factors (and possible therapeutic targets) underlying metabolic dysfunction in the liver. METHODS: We applied a tandem quantitative proteomics strategy to enrich and identify transcription factors (TFs) induced in the obese liver. We used flow cytometry of liver cells to analyze the source of the induced TFs. We employed conditional knockout mice, shRNA, and small-molecule inhibitors to test the metabolic consequences of the induction of identified TFs. Finally, we validated mouse data in patient liver biopsies. RESULTS: We identified PU.1/SPI1, the master hematopoietic regulator, as one of the most upregulated TFs in livers from diet-induced obese (DIO) and genetically obese (db/db) mice. Targeting PU.1 in the whole liver, but not hepatocytes alone, significantly improved glucose homeostasis and suppressed liver inflammation. Consistently, treatment with the PU.1 inhibitor DB1976 markedly reduced inflammation and improved glucose homeostasis and dyslipidemia in DIO mice, and strongly suppressed glucose intolerance, liver steatosis, inflammation, and fibrosis in a dietary NASH mouse model. Furthermore, hepatic PU.1 expression was positively correlated with insulin resistance and inflammation in liver biopsies from patients. CONCLUSIONS: These data suggest that the elevated hematopoietic factor PU.1 promotes liver metabolic dysfunction, and may be a useful therapeutic target for obesity, insulin resistance/T2D, and NASH. LAY SUMMARY: Expression of the immune regulator PU.1 is increased in livers of obesemice and people. Blocking PU.1 improved glucose homeostasis, and reduced liver steatosis, inflammation and fibrosis in mouse models of non-alcoholic steatohepatitis. Inhibition of PU.1 is thus a potential therapeutic strategy for treating obesity-associated liver dysfunction and metabolic diseases.
Authors: Ke Yun Chen; Alejandra De Angulo; Xin Guo; Aditya More; Scott A Ochsner; Eduardo Lopez; David Saul; Weijun Pang; Yuxiang Sun; Neil J McKenna; Qiang Tong Journal: Front Aging Date: 2022-02-02
Authors: Van L T Ha; Noa Erlitzki; Abdelbasset A Farahat; Arvind Kumar; David W Boykin; Gregory M K Poon Journal: Biophys J Date: 2020-08-20 Impact factor: 4.033