1
|
Vázquez-Borrego MC, Del Río-Moreno M, Pyatkov M, Sarmento-Cabral A, Mahmood M, Pelke N, Wnek M, Cordoba-Chacon J, Waxman DJ, Puchowicz MA, McGuinness OP, Kineman RD. Direct and systemic actions of growth hormone receptor (GHR)-signaling on hepatic glycolysis, de novo lipogenesis and insulin sensitivity, associated with steatosis. Metabolism 2023; 144:155589. [PMID: 37182789 PMCID: PMC10843389 DOI: 10.1016/j.metabol.2023.155589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 04/28/2023] [Accepted: 05/08/2023] [Indexed: 05/16/2023]
Abstract
BACKGROUND Evidence is accumulating that growth hormone (GH) protects against the development of steatosis and progression of non-alcoholic fatty liver disease (NAFLD). GH may control steatosis indirectly by altering systemic insulin sensitivity and substrate delivery to the liver and/or by the direct actions of GH on hepatocyte function. APPROACH To better define the hepatocyte-specific role of GH receptor (GHR) signaling on regulating steatosis, we used a mouse model with adult-onset, hepatocyte-specific GHR knockdown (aHepGHRkd). To prevent the reduction in circulating insulin-like growth factor 1 (IGF1) and the subsequent increase in GH observed after aHepGHRkd, subsets of aHepGHRkd mice were treated with adeno-associated viral vectors (AAV) driving hepatocyte-specific expression of IGF1 or a constitutively active form of STAT5b (STAT5bCA). The impact of hepatocyte-specific modulation of GHR, IGF1 and STAT5b on carbohydrate and lipid metabolism was studied across multiple nutritional states and in the context of hyperinsulinemic:euglycemic clamps. RESULTS Chow-fed male aHepGHRkd mice developed steatosis associated with an increase in hepatic glucokinase (GCK) and ketohexokinase (KHK) expression and de novo lipogenesis (DNL) rate, in the post-absorptive state and in response to refeeding after an overnight fast. The aHepGHRkd-associated increase in hepatic KHK, but not GCK and steatosis, was dependent on hepatocyte expression of carbohydrate response element binding protein (ChREBP), in re-fed mice. Interestingly, under clamp conditions, aHepGHRkd also increased the rate of DNL and expression of GCK and KHK, but impaired insulin-mediated suppression of hepatic glucose production, without altering plasma NEFA levels. These effects were normalized with AAV-mediated hepatocyte expression of IGF1 or STAT5bCA. Comparison of the impact of AAV-mediated hepatocyte IGF1 versus STAT5bCA in aHepGHRkd mice across multiple nutritional states, indicated the restorative actions of IGF1 are indirect, by improving systemic insulin sensitivity, independent of changes in the liver transcriptome. In contrast, the actions of STAT5b are due to the combined effects of raising IGF1 and direct alterations in the hepatocyte gene program that may involve suppression of BCL6 and FOXO1 activity. However, the direct and IGF1-dependent actions of STAT5b cannot fully account for enhanced GCK activity and lipogenic gene expression observed after aHepGHRkd, suggesting other GHR-mediated signals are involved. CONCLUSION These studies demonstrate hepatocyte GHR-signaling controls hepatic glycolysis, DNL, steatosis and hepatic insulin sensitivity indirectly (via IGF1) and directly (via STAT5b). The relative contribution of these indirect and direct actions of GH on hepatocytes is modified by insulin and nutrient availability. These results improve our understanding of the physiologic actions of GH on regulating adult metabolism to protect against NAFLD progression.
Collapse
Affiliation(s)
- Mari C Vázquez-Borrego
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Illinois at Chicago, Chicago, IL, United States of America; Research and Development Division, Jesse Brown Veterans Affairs Medical Center, Chicago, IL, United States of America
| | - Mercedes Del Río-Moreno
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Illinois at Chicago, Chicago, IL, United States of America; Research and Development Division, Jesse Brown Veterans Affairs Medical Center, Chicago, IL, United States of America
| | - Maxim Pyatkov
- Department of Biology & Bioinformatics Program, Boston University, Boston, MA, United States of America
| | - André Sarmento-Cabral
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Illinois at Chicago, Chicago, IL, United States of America; Research and Development Division, Jesse Brown Veterans Affairs Medical Center, Chicago, IL, United States of America
| | - Mariyah Mahmood
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Illinois at Chicago, Chicago, IL, United States of America; Research and Development Division, Jesse Brown Veterans Affairs Medical Center, Chicago, IL, United States of America
| | - Natalie Pelke
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Illinois at Chicago, Chicago, IL, United States of America; Research and Development Division, Jesse Brown Veterans Affairs Medical Center, Chicago, IL, United States of America
| | - Magdalena Wnek
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Illinois at Chicago, Chicago, IL, United States of America; Research and Development Division, Jesse Brown Veterans Affairs Medical Center, Chicago, IL, United States of America
| | - Jose Cordoba-Chacon
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Illinois at Chicago, Chicago, IL, United States of America; Research and Development Division, Jesse Brown Veterans Affairs Medical Center, Chicago, IL, United States of America
| | - David J Waxman
- Department of Biology & Bioinformatics Program, Boston University, Boston, MA, United States of America
| | - Michelle A Puchowicz
- Department of Pediatrics, University of Tennessee Health Science Center, Memphis, TN, United States of America
| | - Owen P McGuinness
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, United States of America
| | - Rhonda D Kineman
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Illinois at Chicago, Chicago, IL, United States of America; Research and Development Division, Jesse Brown Veterans Affairs Medical Center, Chicago, IL, United States of America.
| |
Collapse
|
2
|
Goldfarb CN, Karri K, Pyatkov M, Waxman DJ. Interplay Between GH-regulated, Sex-biased Liver Transcriptome and Hepatic Zonation Revealed by Single-Nucleus RNA Sequencing. Endocrinology 2022; 163:6580481. [PMID: 35512247 PMCID: PMC9154260 DOI: 10.1210/endocr/bqac059] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Indexed: 11/19/2022]
Abstract
The zonation of liver metabolic processes is well-characterized; however, little is known about the cell type-specificity and zonation of sexually dimorphic gene expression or its growth hormone (GH)-dependent transcriptional regulators. We address these issues using single-nucleus RNA-sequencing of 32 000 nuclei representing 9 major liver cell types. Nuclei were extracted from livers from adult male and female mice; from males infused with GH continuously, mimicking the female plasma GH pattern; and from mice exposed to TCPOBOP, a xenobiotic agonist ligand of the nuclear receptor CAR that perturbs sex-biased gene expression. Analysis of these rich transcriptomic datasets revealed the following: 1) expression of sex-biased genes and their GH-dependent transcriptional regulators is primarily restricted to hepatocytes and is not a feature of liver nonparenchymal cells; 2) many sex-biased transcripts show sex-dependent zonation within the liver lobule; 3) gene expression is substantially feminized both in periportal and pericentral hepatocytes when male mice are infused with GH continuously; 4) sequencing nuclei increases the sensitivity for detecting thousands of nuclear-enriched long-noncoding RNAs (lncRNAs) and enables determination of their liver cell type-specificity, sex-bias and hepatocyte zonation profiles; 5) the periportal to pericentral hepatocyte cell ratio is significantly higher in male than female liver; and 6) TCPOBOP exposure disrupts both sex-specific gene expression and hepatocyte zonation within the liver lobule. These findings highlight the complex interconnections between hepatic sexual dimorphism and zonation at the single-cell level and reveal how endogenous hormones and foreign chemical exposure can alter these interactions across the liver lobule with large effects both on protein-coding genes and lncRNAs.
Collapse
Affiliation(s)
- Christine N Goldfarb
- Department of Biology, Boston University, Boston, Massachusetts 02215, USA
- Biomedical Engineering, Boston University, Boston, Massachusetts 02215, USA
| | - Kritika Karri
- Department of Biology, Boston University, Boston, Massachusetts 02215, USA
- Bioinformatics Program Boston University, Boston, Massachusetts 02215, USA
| | - Maxim Pyatkov
- Department of Biology, Boston University, Boston, Massachusetts 02215, USA
| | - David J Waxman
- Correspondence: David J. Waxman, PhD, Department of Biology, Boston University, 5 Cummington Mall, Boston, MA 02215, USA.
| |
Collapse
|
3
|
Leboeuf D, Pyatkov M, Zatsepin TS, Piatkov K. The Arg/N-Degron Pathway-A Potential Running Back in Fine-Tuning the Inflammatory Response? Biomolecules 2020; 10:biom10060903. [PMID: 32545869 PMCID: PMC7356051 DOI: 10.3390/biom10060903] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 06/09/2020] [Accepted: 06/12/2020] [Indexed: 12/14/2022] Open
Abstract
Recognition of danger signals by a cell initiates a powerful cascade of events generally leading to inflammation. Inflammatory caspases and several other proteases become activated and subsequently cleave their target proinflammatory mediators. The irreversible nature of this process implies that the newly generated proinflammatory fragments need to be sequestered, inhibited, or degraded in order to cancel the proinflammatory program or prevent chronic inflammation. The Arg/N-degron pathway is a ubiquitin-dependent proteolytic pathway that specifically degrades protein fragments bearing N-degrons, or destabilizing residues, which are recognized by the E3 ligases of the pathway. Here, we report that the Arg/N-degron pathway selectively degrades a number of proinflammatory fragments, including some activated inflammatory caspases, contributing in tuning inflammatory processes. Partial ablation of the Arg/N-degron pathway greatly increases IL-1β secretion, indicating the importance of this ubiquitous pathway in the initiation and resolution of inflammation. Thus, we propose a model wherein the Arg/N-degron pathway participates in the control of inflammation in two ways: in the generation of inflammatory signals by the degradation of inhibitory anti-inflammatory domains and as an “off switch” for inflammatory responses through the selective degradation of proinflammatory fragments.
Collapse
Affiliation(s)
- Dominique Leboeuf
- Skolkovo Institute of Science and Technology, 121205 Moscow, Russia; (D.L.); (T.S.Z.)
| | - Maxim Pyatkov
- Institute of Mathematical Problems of Biology, Keldysh Institute of Applied Mathematics, Russian Academy of Sciences, Pushchino, 142290 Moscow, Russia;
| | - Timofei S. Zatsepin
- Skolkovo Institute of Science and Technology, 121205 Moscow, Russia; (D.L.); (T.S.Z.)
| | - Konstantin Piatkov
- Skolkovo Institute of Science and Technology, 121205 Moscow, Russia; (D.L.); (T.S.Z.)
- Correspondence:
| |
Collapse
|