1
|
Byfield FJ, Eftekhari B, Kaymak-Loveless K, Mandal K, Li D, Wells RG, Chen W, Brujic J, Bergamaschi G, Wuite GJL, Patteson AE, Janmey PA. Metabolically intact nuclei are fluidized by the activity of the chromatin remodeling motor BRG1. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.12.589275. [PMID: 38659735 PMCID: PMC11042217 DOI: 10.1101/2024.04.12.589275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
The structure and dynamics of the cell nucleus regulate nearly every facet of the cell. Changes in nuclear shape limit cell motility and gene expression. Although the nucleus is generally seen as the stiffest organelle in the cell, cells can nevertheless deform the nucleus to large strains by small mechanical stresses. Here, we show that the mechanical response of the cell nucleus exhibits active fluidization that is driven by the BRG 1 motor of the SWI/SNF/BAF chromatin-remodeling complex. Atomic force microscopy measurements show that the nucleus alters stiffness in response to the cell substrate stiffness, which is retained after the nucleus is isolated and that the work of nuclear compression is mostly dissipated rather than elastically stored. Inhibiting BRG 1 stiffens the nucleus and eliminates dissipation and nuclear remodeling both in isolated nuclei and in intact cells. These findings demonstrate a novel link between nuclear motor activity and global nuclear mechanics.
Collapse
|
2
|
Kumar M, Knapp JA, Gupta K, Ryan TA. Isolation and Lipidomic Profiling of Neuronal Lipid Droplets: Unveiling the Lipid Landscape for insights into Neurodegenerative Disorders. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.13.571527. [PMID: 38168251 PMCID: PMC10760103 DOI: 10.1101/2023.12.13.571527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
Recent advances have expanded the role of lipid droplets (LDs) beyond passive lipid storage, implicating their involvement in various metabolic processes across mammalian tissues. Neuronal LDs, long debated in existence, have been identified in several neural structures, raising questions about their contribution to neurodegenerative disorders. Elucidating the specific chemical makeup of these organelles within neurons is critical for understanding their implication in neural pathologies. This study outlines an improved methodology to stimulate and isolate mature LDs from cultured primary neurons, offering insights into their unique lipid-protein composition. Integrating this method with high-throughput techniques may unveil disease-specific alterations in lipid metabolism, providing avenues for potential therapeutic interventions.
Collapse
Affiliation(s)
- Mukesh Kumar
- Department of Biochemistry, Weill Cornell Medicine, New York, NY 10065, USA
| | - Justin A Knapp
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Kallol Gupta
- Aligning Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, Maryland 20815, USA
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06520, USA
- Nanobiology Institute, Yale University, West Haven, CT 06516, USA
| | - Timothy A. Ryan
- Department of Biochemistry, Weill Cornell Medicine, New York, NY 10065, USA
- Aligning Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, Maryland 20815, USA
| |
Collapse
|
3
|
Dempsey JL, Ioannou GN, Carr RM. Mechanisms of Lipid Droplet Accumulation in Steatotic Liver Diseases. Semin Liver Dis 2023; 43:367-382. [PMID: 37799111 DOI: 10.1055/a-2186-3557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/07/2023]
Abstract
The steatotic diseases of metabolic dysfunction-associated steatotic liver disease (MASLD), alcohol-associated liver disease (ALD), and chronic hepatitis C (HCV) account for the majority of liver disease prevalence, morbidity, and mortality worldwide. While these diseases have distinct pathogenic and clinical features, dysregulated lipid droplet (LD) organelle biology represents a convergence of pathogenesis in all three. With increasing understanding of hepatocyte LD biology, we now understand the roles of LD proteins involved in these diseases but also how genetics modulate LD biology to either exacerbate or protect against the phenotypes associated with steatotic liver diseases. Here, we review the history of the LD organelle and its biogenesis and catabolism. We also review how this organelle is critical not only for the steatotic phenotype of liver diseases but also for their advanced phenotypes. Finally, we summarize the latest attempts and challenges of leveraging LD biology for therapeutic gain in steatotic diseases. In conclusion, the study of dysregulated LD biology may lead to novel therapeutics for the prevention of disease progression in the highly prevalent steatotic liver diseases of MASLD, ALD, and HCV.
Collapse
Affiliation(s)
- Joseph L Dempsey
- Division of Gastroenterology, Department of Medicine, School of Medicine, University of Washington, Seattle, Washington
| | - George N Ioannou
- Division of Gastroenterology, Department of Medicine, School of Medicine, University of Washington, Seattle, Washington
- Division of Gastroenterology, Veterans Affairs Puget Sound Healthcare System Seattle, Washington
| | - Rotonya M Carr
- Division of Gastroenterology, Department of Medicine, School of Medicine, University of Washington, Seattle, Washington
| |
Collapse
|
4
|
Hu J, Liu Y, Du Y, Peng X, Liu Z. Cellular organelles as drug carriers for disease treatment. J Control Release 2023; 363:114-135. [PMID: 37742846 DOI: 10.1016/j.jconrel.2023.09.038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 09/18/2023] [Accepted: 09/19/2023] [Indexed: 09/26/2023]
Abstract
Organelles not only constitute the basic structure of the cell but also are important in maintaining the normal physiological activities of the cell. With the development of biomimetic nanoscience, researchers have developed technologies to use organelles as drug carriers for disease treatment. Compared with traditional drug carriers, organelle drug carriers have the advantages of good biocompatibility, high drug loading efficiency, and modifiability, and the surface biomarkers of organelles can also participate in intracellular signal transduction to enhance intracellular and intercellular communication, and assist in enhancing the therapeutic effect of drugs. Among different types of organelles, extracellular vesicles, lipid droplets, lysosomes, and mitochondria have been used as drug carriers. This review briefly reviews the biogenesis, isolation methods, and drug-loading methods of four types of organelles, and systematically summarizes the research progress in using organelles as drug-delivery systems for disease treatment. Finally, the challenges faced by organelle-based drug delivery systems are discussed. Although the organelle-based drug delivery systems still face challenges before they can achieve clinical translation, they offer a new direction and vision for the development of next-generation drug carriers.
Collapse
Affiliation(s)
- Jiaxin Hu
- Department of Pharmaceutics, Xiangya School of Pharmaceutical Sciences, Central South University, Changsha 410013, Hunan Province, PR China
| | - Yanfei Liu
- Department of Pharmaceutical Engineering, College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, Hunan Province, PR China
| | - Yimin Du
- Department of Pharmaceutics, Xiangya School of Pharmaceutical Sciences, Central South University, Changsha 410013, Hunan Province, PR China
| | - Xingxing Peng
- Department of Pharmaceutics, Xiangya School of Pharmaceutical Sciences, Central South University, Changsha 410013, Hunan Province, PR China
| | - Zhenbao Liu
- Department of Pharmaceutics, Xiangya School of Pharmaceutical Sciences, Central South University, Changsha 410013, Hunan Province, PR China; Molecular Imaging Research Center of Central South University, Changsha 410008, Hunan Province, PR China.
| |
Collapse
|
5
|
Oxidative Stress and Lipid Dysregulation in Lipid Droplets: A Connection to Chronic Kidney Disease Revealed in Human Kidney Cells. Antioxidants (Basel) 2022; 11:antiox11071387. [PMID: 35883878 PMCID: PMC9312214 DOI: 10.3390/antiox11071387] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 07/10/2022] [Accepted: 07/14/2022] [Indexed: 02/04/2023] Open
Abstract
Chronic kidney disease (CKD), which is defined as a condition causing the gradual loss of kidney function, shows renal lipid droplet (LD) accumulation that is associated with oxidative damage. There is a possibility that an LD abnormality in quality plays a role in CKD development. This study aimed to explore the chemical composition of LDs that are induced in human kidney cells during exposure to free fatty acids as an LD source and oxidized lipoproteins as oxidative stress. The LDs were aspirated directly from cells using nanotips, followed by in-tip microextraction, and the LD lipidomic profiling was conducted using nanoelectrospray mass spectrometry. As a result, the free fatty acids increased the LD lipid content and, at the same time, changed their composition significantly. The oxidized lipoproteins caused distorted proportions of intact lipids, such as triacylglycerols (TG), phosphatidylcholines (PC), phosphatidylethanolamines (PE), and cholesteryl esters (CE). Notably, the oxidized lipids, including the hydroperoxides of TG, PC, and PE, exhibited significant elevations in dose-dependent manners. Furthermore, the dysregulation of intact lipids was paralleled with the accumulation of lipid hydroperoxides. The present study has revealed that the oxidation of lipids and the dysregulation of the lipid metabolism coexisted in LDs in the kidney cells, which has provided a potential new target for diagnosis and new insights into CKD.
Collapse
|
6
|
Correnti J, Lin C, Brettschneider J, Kuriakose A, Jeon S, Scorletti E, Oranu A, McIver-Jenkins D, Kaneza I, Buyco D, Saiman Y, Furth EE, Argemi J, Bataller R, Holland WL, Carr RM. Liver-specific ceramide reduction alleviates steatosis and insulin resistance in alcohol-fed mice. J Lipid Res 2020; 61:983-994. [PMID: 32398264 PMCID: PMC7328039 DOI: 10.1194/jlr.ra119000446] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2020] [Revised: 04/29/2020] [Indexed: 12/20/2022] Open
Abstract
Alcohol's impairment of both hepatic lipid metabolism and insulin resistance (IR) are key drivers of alcoholic steatosis, the initial stage of alcoholic liver disease (ALD). Pharmacologic reduction of lipotoxic ceramide prevents alcoholic steatosis and glucose intolerance in mice, but potential off-target effects limit its strategic utility. Here, we employed a hepatic-specific acid ceramidase (ASAH) overexpression model to reduce hepatic ceramides in a Lieber-DeCarli model of experimental alcoholic steatosis. We examined effects of alcohol on hepatic lipid metabolism, body composition, energy homeostasis, and insulin sensitivity as measured by hyperinsulinemic-euglycemic clamp. Our results demonstrate that hepatic ceramide reduction ameliorates the effects of alcohol on hepatic lipid droplet (LD) accumulation by promoting VLDL secretion and lipophagy, the latter of which involves ceramide cross-talk between the lysosomal and LD compartments. We additionally demonstrate that hepatic ceramide reduction prevents alcohol's inhibition of hepatic insulin signaling. These effects on the liver are associated with a reduction in oxidative stress markers and are relevant to humans, as we observe peri- LD ASAH expression in human ALD. Together, our results suggest a potential role for hepatic ceramide inhibition in preventing ALD.
Collapse
Affiliation(s)
- Jason Correnti
- Division of Gastroenterology, University of Pennsylvania, Philadelphia, PA
| | - Chelsea Lin
- Division of Gastroenterology, University of Pennsylvania, Philadelphia, PA
| | | | - Amy Kuriakose
- Division of Gastroenterology, University of Pennsylvania, Philadelphia, PA
| | - Sookyoung Jeon
- Division of Gastroenterology, University of Pennsylvania, Philadelphia, PA
| | - Eleonora Scorletti
- Division of Gastroenterology, University of Pennsylvania, Philadelphia, PA
| | - Amanke Oranu
- Division of Gastroenterology, United Health Services, Binghamton, NY
| | - Dru McIver-Jenkins
- Division of Gastroenterology, University of Pennsylvania, Philadelphia, PA
| | - Isabelle Kaneza
- Division of Gastroenterology, University of Pennsylvania, Philadelphia, PA
| | - Delfin Buyco
- Division of Gastroenterology, University of Pennsylvania, Philadelphia, PA
| | - Yedidya Saiman
- Division of Gastroenterology, University of Pennsylvania, Philadelphia, PA
| | - Emma E Furth
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA
| | - Josepmaria Argemi
- Center for Liver Diseases, Pittsburgh Research Center, University of Pittsburgh Medical Center, Pittsburgh, PA
| | - Ramon Bataller
- Center for Liver Diseases, Pittsburgh Research Center, University of Pittsburgh Medical Center, Pittsburgh, PA
| | - William L Holland
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, UT
| | - Rotonya M Carr
- Division of Gastroenterology, University of Pennsylvania, Philadelphia, PA. mailto:
| |
Collapse
|