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Ocket E, Matthaeus C. Insights in caveolae protein structure arrangements and their local lipid environment. Biol Chem 2024; 0:hsz-2024-0046. [PMID: 38970809 DOI: 10.1515/hsz-2024-0046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2024] [Accepted: 06/19/2024] [Indexed: 07/08/2024]
Abstract
Caveolae are 50-80 nm sized plasma membrane invaginations found in adipocytes, endothelial cells or fibroblasts. They are involved in endocytosis, lipid uptake and the regulation of the cellular lipid metabolism as well as sensing and adapting to changes in plasma membrane tension. Caveolae are characterized by their unique lipid composition and their specific protein coat consisting of caveolin and cavin proteins. Recently, detailed structural information was obtained for the major caveolae protein caveolin1 showing the formation of a disc-like 11-mer protein complex. Furthermore, the importance of the cavin disordered regions in the generation of cavin trimers and caveolae at the plasma membrane were revealed. Thus, finally, structural insights about the assembly of the caveolar coat can be elucidated. Here, we review recent developments in caveolae structural biology with regard to caveolae coat formation and caveolae curvature generation. Secondly, we discuss the importance of specific lipid species necessary for caveolae curvature and formation. In the last years, it was shown that specifically sphingolipids, cholesterol and fatty acids can accumulate in caveolae invaginations and may drive caveolae endocytosis. Throughout, we summarize recent studies in the field and highlight future research directions.
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Affiliation(s)
- Esther Ocket
- Institute of Nutritional Science, Cellular Physiology of Nutrition, University of Potsdam, Karl-Liebknecht-Str. 24/25, Building 29, Room 0.08, D-14476 Potsdam, Germany
| | - Claudia Matthaeus
- Institute of Nutritional Science, Cellular Physiology of Nutrition, University of Potsdam, Karl-Liebknecht-Str. 24/25, Building 29, Room 0.08, D-14476 Potsdam, Germany
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2
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Song E, Han S, Hohng S, Kang C. Compatibility of termination mechanisms in bacterial transcription with inference on eukaryotic models. Biochem Soc Trans 2024; 52:887-897. [PMID: 38533838 DOI: 10.1042/bst20231229] [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: 01/19/2024] [Revised: 03/18/2024] [Accepted: 03/18/2024] [Indexed: 03/28/2024]
Abstract
Transcription termination has evolved to proceed through diverse mechanisms. For several classes of terminators, multiple models have been debatably proposed. Recent single-molecule studies on bacterial terminators have resolved several long-standing controversies. First, termination mode or outcome is twofold rather than single. RNA is released alone before DNA or together with DNA from RNA polymerase (RNAP), i.e. with RNA release for termination, RNAP retains on or dissociates off DNA, respectively. The concomitant release, described in textbooks, results in one-step decomposition of transcription complexes, and this 'decomposing termination' prevails at ρ factor-dependent terminators. Contrastingly, the sequential release was recently discovered abundantly from RNA hairpin-dependent intrinsic terminations. RNA-only release allows RNAP to diffuse on DNA in both directions and recycle for reinitiation. This 'recycling termination' enables one-dimensional reinitiation, which would be more expeditious than three-dimensional reinitiation by RNAP dissociated at decomposing termination. Second, while both recycling and decomposing terminations occur at a hairpin-dependent terminator, four termination mechanisms compatibly operate at a ρ-dependent terminator with ρ in alternative modes and even intrinsically without ρ. RNA-bound catch-up ρ mediates recycling termination first and decomposing termination later, while RNAP-prebound stand-by ρ invokes only decomposing termination slowly. Without ρ, decomposing termination occurs slightly and sluggishly. These four mechanisms operate on distinct timescales, providing orderly fail-safes. The stand-by mechanism is benefited by terminational pause prolongation and modulated by accompanying riboswitches more greatly than the catch-up mechanisms. Conclusively, any mechanism alone is insufficient to perfect termination, and multiple mechanisms operate compatibly to achieve maximum possible efficiency under separate controls.
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Affiliation(s)
- Eunho Song
- Department of Physics and Astronomy, and Institute of Applied Physics, Seoul National University, Seoul 08826, Republic of Korea
| | - Sun Han
- Department of Physics and Astronomy, and Institute of Applied Physics, Seoul National University, Seoul 08826, Republic of Korea
| | - Sungchul Hohng
- Department of Physics and Astronomy, and Institute of Applied Physics, Seoul National University, Seoul 08826, Republic of Korea
| | - Changwon Kang
- Department of Biological Sciences, and KAIST Stem Cell Center, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea
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3
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Wen Y, Xu F, Zhang H. Circ_0049271 targets the miR-1197/PTRF axis to attenuate the malignancy of osteosarcoma. Cancer Biomark 2024; 40:141-153. [PMID: 38578882 PMCID: PMC11321495 DOI: 10.3233/cbm-230191] [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: 05/10/2023] [Accepted: 01/08/2024] [Indexed: 04/07/2024]
Abstract
BACKGROUND Circular RNAs (circRNAs) perform key regulatory functions in osteosarcoma (OS) tumorigenesis. In this study, we aimed to explore the detailed action mechanisms of circ_0049271 in OS progression. METHODS Cell colony formation, cell counting kit-8, and transwell assays were performed to assess the proliferation and invasion of OS cells. Quantitative reverse transcription-polymerase chain reaction and western blotting were used to determine the expression levels of polymerase 1 and transcript release factor (PTRF), microRNA (miR)-1197, and circ_0049271 in OS cells. Furthermore, RNA immunoprecipitation and dual luciferase assays were conducted to explore the targeted relationships among PTRF, miR-1197, and circ_0049271. Finally, a tumor formation assay was conducted to determine the effects of circ_0049271 on in vivo tumor growth in mice. RESULTS High expression levels of miR-1197 and low levels of circ_0049271 and PTRF were observed in OS cells. circ _0049271 targeted miR-1197 to mediate PTRF expression. Moreover, the proliferation and invasion of OS cells were repressed by circ_0049271 or PTRF overexpression and increased by miR-1197 upregulation. Enforced circ_0049271 also impeded tumor growth in vivo. Upregulation of miR-1197 reversed the antitumor effects of circ_0049271 on OS progression in vitro; however, PTRF overexpression attenuated the cancer-promoting effects of miR-1197 on OS in vitro. CONCLUSIONS Our findings revealed that circ_0049271 targeted the miR-1197/PTRF axis to attenuate the malignancy of OS, suggesting a potential target for its clinical treatment.
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Affiliation(s)
- Yixin Wen
- Orthopaedics Department, Fifth Hospital of Wuhan, Wuhan, Hubei, China
| | - Feng Xu
- Orthopaedics Department, Fifth Hospital of Wuhan, Wuhan, Hubei, China
- Orthopaedics Department, Fifth Hospital of Wuhan, Wuhan, Hubei, China
| | - Hui Zhang
- Orthopaedics Department, Fifth Hospital of Wuhan, Wuhan, Hubei, China
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Daiß JL, Griesenbeck J, Tschochner H, Engel C. Synthesis of the ribosomal RNA precursor in human cells: mechanisms, factors and regulation. Biol Chem 2023; 404:1003-1023. [PMID: 37454246 DOI: 10.1515/hsz-2023-0214] [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: 05/12/2023] [Accepted: 07/04/2023] [Indexed: 07/18/2023]
Abstract
The ribosomal RNA precursor (pre-rRNA) comprises three of the four ribosomal RNAs and is synthesized by RNA polymerase (Pol) I. Here, we describe the mechanisms of Pol I transcription in human cells with a focus on recent insights gained from structure-function analyses. The comparison of Pol I-specific structural and functional features with those of other Pols and with the excessively studied yeast system distinguishes organism-specific from general traits. We explain the organization of the genomic rDNA loci in human cells, describe the Pol I transcription cycle regarding structural changes in the enzyme and the roles of human Pol I subunits, and depict human rDNA transcription factors and their function on a mechanistic level. We disentangle information gained by direct investigation from what had apparently been deduced from studies of the yeast enzymes. Finally, we provide information about how Pol I mutations may contribute to developmental diseases, and why Pol I is a target for new cancer treatment strategies, since increased rRNA synthesis was correlated with rapidly expanding cell populations.
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Affiliation(s)
- Julia L Daiß
- Regensburg Center for Biochemistry, University of Regensburg, D-93053 Regensburg, Germany
| | - Joachim Griesenbeck
- Regensburg Center for Biochemistry, University of Regensburg, D-93053 Regensburg, Germany
| | - Herbert Tschochner
- Regensburg Center for Biochemistry, University of Regensburg, D-93053 Regensburg, Germany
| | - Christoph Engel
- Regensburg Center for Biochemistry, University of Regensburg, D-93053 Regensburg, Germany
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5
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Du J, Liu Y, Lan G, Zhou Y, Ni Y, Liao K, Zheng F, Cheng Q, Shi G, Su X. PTRF-IL33-ZBP1 signaling mediating macrophage necroptosis contributes to HDM-induced airway inflammation. Cell Death Dis 2023; 14:432. [PMID: 37454215 PMCID: PMC10349813 DOI: 10.1038/s41419-023-05971-1] [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: 12/23/2022] [Revised: 06/29/2023] [Accepted: 07/06/2023] [Indexed: 07/18/2023]
Abstract
Polymerase 1 and transcript release factor (PTRF, encoding by Cavin-1) regulates interleukin 33 (IL-33) release, which is implicated in asthma development. Z-DNA binding protein 1 (ZBP1)-sensing Z-RNAs induces necroptosis which causes inflammatory diseases. House dust mite (HDM) is the major source of allergen in house dust and is strongly associated with the development of asthma. Whether PTRF via IL-33 and ZBP1 mediates HDM-induced macrophage necroptosis and airway inflammation remains unclear. Here, we found that deficiency of PTRF could reduce lung IL-33, ZBP1, phosphor-receptor-interacting protein kinase 3 (p-RIPK3), and phosphor-mixed lineage kinase domain-like (p-MLKL) (necroptosis executioner), and airway inflammation in an HDM-induced asthma mouse model. In HDM-treated macrophages, ZBP1, p-RIPK3, and p-MLKL levels were markedly increased, and these changes were reversed by deletion of Cavin-1. Deletion of Il33 also reduced expression of ZBP1, p-RIPK3, and p-MLKL in HDM-challenged lungs. Moreover, IL-33 synergizing with HDM boosted expression of ZBP1, p-RIPK3, and p-MLKL in macrophages. In bronchial epithelial cells rather than macrophages and vascular endothelial cells, PTRF positively regulates IL-33 expression. Therefore, we conclude that PTRF mediates HDM-induced macrophage ZBP1/necroptosis and airway inflammation, and this effect could be boosted by bronchial epithelial cell-derived IL-33. Our findings suggest that PTRF-IL33-ZBP1 signaling pathway might be a promising target for dampening airway inflammation.
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Affiliation(s)
- Juan Du
- Department of Pulmonary and Critical Care Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Shanghai Key Laboratory of Emergency Prevention, Diagnosis and Treatment of Respiratory Infectious Diseases, Shanghai, China
| | - Yahui Liu
- Department of Pulmonary and Critical Care Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Shanghai Key Laboratory of Emergency Prevention, Diagnosis and Treatment of Respiratory Infectious Diseases, Shanghai, China
| | - Gelei Lan
- Department of Pulmonary and Critical Care Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Shanghai Key Laboratory of Emergency Prevention, Diagnosis and Treatment of Respiratory Infectious Diseases, Shanghai, China
| | - Yao Zhou
- Department of Pediatrics, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yingmeng Ni
- Department of Pulmonary and Critical Care Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Shanghai Key Laboratory of Emergency Prevention, Diagnosis and Treatment of Respiratory Infectious Diseases, Shanghai, China
| | - Kai Liao
- Laboratory of Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Fang Zheng
- Department of Immunology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Qijian Cheng
- Department of Pulmonary and Critical Care Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Shanghai Key Laboratory of Emergency Prevention, Diagnosis and Treatment of Respiratory Infectious Diseases, Shanghai, China
| | - Guochao Shi
- Department of Pulmonary and Critical Care Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
- Shanghai Key Laboratory of Emergency Prevention, Diagnosis and Treatment of Respiratory Infectious Diseases, Shanghai, China.
| | - Xiao Su
- Unit of Respiratory Infection and Immunity, Institute Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, China.
- Shanghai Key Laboratory of Lung Inflammation and Injury, Shanghai, China.
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6
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Xie J, Libri D, Porrua O. Mechanisms of eukaryotic transcription termination at a glance. J Cell Sci 2023; 136:286227. [PMID: 36594557 DOI: 10.1242/jcs.259873] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Transcription termination is the final step of a transcription cycle, which induces the release of the transcript at the termination site and allows the recycling of the polymerase for the next round of transcription. Timely transcription termination is critical for avoiding interferences between neighbouring transcription units as well as conflicts between transcribing RNA polymerases (RNAPs) and other DNA-associated processes, such as replication or DNA repair. Understanding the mechanisms by which the very stable transcription elongation complex is dismantled is essential for appreciating how physiological gene expression is maintained and also how concurrent processes that occur synchronously on the DNA are coordinated. Although the strategies employed by the different classes of eukaryotic RNAPs are traditionally considered to be different, novel findings point to interesting commonalities. In this Cell Science at a Glance and the accompanying poster, we review the current understanding about the mechanisms of transcription termination by the three eukaryotic RNAPs.
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Affiliation(s)
- Juanjuan Xie
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
| | - Domenico Libri
- Institut de Génétique Moléculaire de Montpellier, Univ Montpellier, CNRS, Montpellier, France
| | - Odil Porrua
- Institut de Génétique Moléculaire de Montpellier, Univ Montpellier, CNRS, Montpellier, France
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Enyong EN, Gurley JM, De Ieso ML, Stamer WD, Elliott MH. Caveolar and non-Caveolar Caveolin-1 in ocular homeostasis and disease. Prog Retin Eye Res 2022; 91:101094. [PMID: 35729002 PMCID: PMC9669151 DOI: 10.1016/j.preteyeres.2022.101094] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 06/03/2022] [Accepted: 06/10/2022] [Indexed: 11/17/2022]
Abstract
Caveolae, specialized plasma membrane invaginations present in most cell types, play important roles in multiple cellular processes including cell signaling, lipid uptake and metabolism, endocytosis and mechanotransduction. They are found in almost all cell types but most abundant in endothelial cells, adipocytes and fibroblasts. Caveolin-1 (Cav1), the signature structural protein of caveolae was the first protein associated with caveolae, and in association with Cavin1/PTRF is required for caveolae formation. Genetic ablation of either Cav1 or Cavin1/PTRF downregulates expression of the other resulting in loss of caveolae. Studies using Cav1-deficient mouse models have implicated caveolae with human diseases such as cardiomyopathies, lipodystrophies, diabetes and muscular dystrophies. While caveolins and caveolae are extensively studied in extra-ocular settings, their contributions to ocular function and disease pathogenesis are just beginning to be appreciated. Several putative caveolin/caveolae functions are relevant to the eye and Cav1 is highly expressed in retinal vascular and choroidal endothelium, Müller glia, the retinal pigment epithelium (RPE), and the Schlemm's canal endothelium and trabecular meshwork cells. Variants at the CAV1/2 gene locus are associated with risk of primary open angle glaucoma and the high risk HTRA1 variant for age-related macular degeneration is thought to exert its effect through regulation of Cav1 expression. Caveolins also play important roles in modulating retinal neuroinflammation and blood retinal barrier permeability. In this article, we describe the current state of caveolin/caveolae research in the context of ocular function and pathophysiology. Finally, we discuss new evidence showing that retinal Cav1 exists and functions outside caveolae.
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Affiliation(s)
- Eric N Enyong
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA; Department of Ophthalmology, Dean A. McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Jami M Gurley
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA; Department of Ophthalmology, Dean A. McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Michael L De Ieso
- Department of Ophthalmology, Duke Eye Center, Duke University, Durham, NC, USA
| | - W Daniel Stamer
- Department of Ophthalmology, Duke Eye Center, Duke University, Durham, NC, USA
| | - Michael H Elliott
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA; Department of Ophthalmology, Dean A. McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.
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8
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Structural insights into nuclear transcription by eukaryotic DNA-dependent RNA polymerases. Nat Rev Mol Cell Biol 2022; 23:603-622. [PMID: 35505252 DOI: 10.1038/s41580-022-00476-9] [Citation(s) in RCA: 39] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/18/2022] [Indexed: 02/07/2023]
Abstract
The eukaryotic transcription apparatus synthesizes a staggering diversity of RNA molecules. The labour of nuclear gene transcription is, therefore, divided among multiple DNA-dependent RNA polymerases. RNA polymerase I (Pol I) transcribes ribosomal RNA, Pol II synthesizes messenger RNAs and various non-coding RNAs (including long non-coding RNAs, microRNAs and small nuclear RNAs) and Pol III produces transfer RNAs and other short RNA molecules. Pol I, Pol II and Pol III are large, multisubunit protein complexes that associate with a multitude of additional factors to synthesize transcripts that largely differ in size, structure and abundance. The three transcription machineries share common characteristics, but differ widely in various aspects, such as numbers of RNA polymerase subunits, regulatory elements and accessory factors, which allows them to specialize in transcribing their specific RNAs. Common to the three RNA polymerases is that the transcription process consists of three major steps: transcription initiation, transcript elongation and transcription termination. In this Review, we outline the common principles and differences between the Pol I, Pol II and Pol III transcription machineries and discuss key structural and functional insights obtained into the three stages of their transcription processes.
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9
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Qifti A, Balaji S, Scarlata S. Deformation of caveolae impacts global transcription and translation processes through relocalization of cavin-1. J Biol Chem 2022; 298:102005. [PMID: 35513070 PMCID: PMC9168624 DOI: 10.1016/j.jbc.2022.102005] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 04/16/2022] [Accepted: 04/19/2022] [Indexed: 11/17/2022] Open
Abstract
Caveolae are invaginated membrane domains that provide mechanical strength to cells in addition to being focal points for the localization of signaling molecules. Caveolae are formed through the aggregation of caveolin-1 or -3 (Cav1/3), membrane proteins that assemble into multifunctional complexes with the help of caveola-associated protein cavin-1. In addition to its role in the formation of caveolae, cavin-1, also called polymerase I and transcript release factor, is further known to promote ribosomal RNA transcription in the nucleus. However, the mechanistic link between these functions is not clear. Here, we found that deforming caveolae by subjecting cells to mild osmotic stress (150–300 mOsm) changes levels of GAPDH, Hsp90, and Ras only when Cav1/cavin-1 levels are reduced, suggesting a link between caveola deformation and global protein expression. We show that this link may be due to relocalization of cavin-1 to the nucleus upon caveola deformation. Cavin-1 relocalization is also seen when Cav1-Gαq contacts change upon stimulation. Furthermore, Cav1 and cavin-1 levels have been shown to have profound effects on cytosolic RNA levels, which in turn impact the ability of cells to form stress granules and RNA-processing bodies (p-bodies) which sequester and degrade mRNAs, respectively. Our studies here using a cavin-1-knockout cell line indicate adaptive changes in cytosolic RNA levels but a reduced ability to form stress granules. Taken together, our findings suggest that caveolae, through release of cavin-1, communicate extracellular cues to the cell interior to impact transcriptional and translational.
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10
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Huang W, Hong Y, He W, Jiang L, Deng W, Peng B, Tang F, Shen C, Lan Q, Huang H, Zhong H, Lv J, Zeng S, Li M, OuYang Y, Liang J, Mo Z, Chen Q, Cui L, Zhang M, Xu F, Zhou Z. Cavin-1 promotes M2 macrophages/microglia polarization via SOCS3. Inflamm Res 2022; 71:397-407. [PMID: 35275225 DOI: 10.1007/s00011-022-01550-w] [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: 10/01/2021] [Revised: 02/13/2022] [Accepted: 02/17/2022] [Indexed: 11/27/2022] Open
Abstract
PURPOSE Our study aimed to investigate the function of Cavin-1 and SOCS3 in macrophages/microglia M2 polarization and further explored the relevant mechanism. METHODS Expression levels of Cavin-1 and SOCS3 in macrophages/microglia were measured by western blotting and RT-PCR, respectively. Then, Cavin-1 or SOCS3 was gene silenced by a siRNA approach, and gene silencing efficiency was determined by western blotting. Next, co-immunoprecipitation (Co-IP) was employed to further analyze the interaction between Cavin-1 and SOCS3. Finally, the activation of STAT6/PPAR-γ signaling was evaluated using western blotting, and the M2 macrophages/microglia polarization was validated by measuring the mRNA expression of M2 markers by RT-PCR. RESULTS In the polarization process of macrophages/microglia to M2 phenotype, both Cavin-1 and SOCS3 increased synchronously at protein and mRNA level, reached the peak at the 6 h, and then decreased. After Cavin-1 or SOCS3 silencing, the expression of Cavin-1 and SOCS3 declined. These results suggested that Cavin-1 and SOCS3 were positively correlated in macrophages/microglia, and this conjecture was verified by Co-IP. Besides, Cavin-1 silencing not only suppressed the activation of STAT6/PPAR-γ pathway, but also suppressed the release of anti-inflammatory factors. Finally, we found that SOCS3 overexpression reversed the inhibitory effect of Cavin-1 silencing on the release of anti-inflammatory factors in M2 macrophages/microglia. CONCLUSIONS Cavin-1 and SOCS3 are actively involved in the process of M2 macrophages/microglia polarization. As a SOCS3 interacting protein, Cavin-1 can promote M2 macrophages/microglia polarization via SOCS3.
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Affiliation(s)
- Wei Huang
- Guangxi Health Commission Key Laboratory of Ophthalmology and Related Systemic Diseases Artificial Intelligence Screening Technology & Research Center of Ophthalmology, Guangxi Academy of Medical Sciences & Department of Ophthalmology, The People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, 530021, China
| | - Yiyi Hong
- Guangxi Health Commission Key Laboratory of Ophthalmology and Related Systemic Diseases Artificial Intelligence Screening Technology & Research Center of Ophthalmology, Guangxi Academy of Medical Sciences & Department of Ophthalmology, The People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, 530021, China
| | - Wenjing He
- Guangxi Health Commission Key Laboratory of Ophthalmology and Related Systemic Diseases Artificial Intelligence Screening Technology & Research Center of Ophthalmology, Guangxi Academy of Medical Sciences & Department of Ophthalmology, The People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, 530021, China
| | - Li Jiang
- Guangxi Health Commission Key Laboratory of Ophthalmology and Related Systemic Diseases Artificial Intelligence Screening Technology & Research Center of Ophthalmology, Guangxi Academy of Medical Sciences & Department of Ophthalmology, The People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, 530021, China
| | - Wen Deng
- Guangxi Health Commission Key Laboratory of Ophthalmology and Related Systemic Diseases Artificial Intelligence Screening Technology & Research Center of Ophthalmology, Guangxi Academy of Medical Sciences & Department of Ophthalmology, The People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, 530021, China
| | - Biyan Peng
- Guangxi Health Commission Key Laboratory of Ophthalmology and Related Systemic Diseases Artificial Intelligence Screening Technology & Research Center of Ophthalmology, Guangxi Academy of Medical Sciences & Department of Ophthalmology, The People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, 530021, China
| | - Fen Tang
- Guangxi Health Commission Key Laboratory of Ophthalmology and Related Systemic Diseases Artificial Intelligence Screening Technology & Research Center of Ophthalmology, Guangxi Academy of Medical Sciences & Department of Ophthalmology, The People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, 530021, China
| | - Chaolan Shen
- Guangxi Health Commission Key Laboratory of Ophthalmology and Related Systemic Diseases Artificial Intelligence Screening Technology & Research Center of Ophthalmology, Guangxi Academy of Medical Sciences & Department of Ophthalmology, The People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, 530021, China
| | - Qianqian Lan
- Guangxi Health Commission Key Laboratory of Ophthalmology and Related Systemic Diseases Artificial Intelligence Screening Technology & Research Center of Ophthalmology, Guangxi Academy of Medical Sciences & Department of Ophthalmology, The People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, 530021, China
| | - Hui Huang
- Guangxi Health Commission Key Laboratory of Ophthalmology and Related Systemic Diseases Artificial Intelligence Screening Technology & Research Center of Ophthalmology, Guangxi Academy of Medical Sciences & Department of Ophthalmology, The People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, 530021, China
| | - Haibin Zhong
- Guangxi Health Commission Key Laboratory of Ophthalmology and Related Systemic Diseases Artificial Intelligence Screening Technology & Research Center of Ophthalmology, Guangxi Academy of Medical Sciences & Department of Ophthalmology, The People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, 530021, China
| | - Jian Lv
- Guangxi Health Commission Key Laboratory of Ophthalmology and Related Systemic Diseases Artificial Intelligence Screening Technology & Research Center of Ophthalmology, Guangxi Academy of Medical Sciences & Department of Ophthalmology, The People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, 530021, China
| | - Siming Zeng
- Guangxi Health Commission Key Laboratory of Ophthalmology and Related Systemic Diseases Artificial Intelligence Screening Technology & Research Center of Ophthalmology, Guangxi Academy of Medical Sciences & Department of Ophthalmology, The People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, 530021, China
| | - Min Li
- Guangxi Health Commission Key Laboratory of Ophthalmology and Related Systemic Diseases Artificial Intelligence Screening Technology & Research Center of Ophthalmology, Guangxi Academy of Medical Sciences & Department of Ophthalmology, The People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, 530021, China
| | - Yiqiang OuYang
- Laboratory Animal Center, Guangxi Medical University, Nanning, 530021, China
| | - Jinning Liang
- Laboratory Animal Center, Guangxi Medical University, Nanning, 530021, China
| | - Zhongxiang Mo
- Laboratory Animal Center, Guangxi Medical University, Nanning, 530021, China
| | - Qi Chen
- Guangxi Health Commission Key Laboratory of Ophthalmology and Related Systemic Diseases Artificial Intelligence Screening Technology & Research Center of Ophthalmology, Guangxi Academy of Medical Sciences & Department of Ophthalmology, The People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, 530021, China
| | - Ling Cui
- Guangxi Health Commission Key Laboratory of Ophthalmology and Related Systemic Diseases Artificial Intelligence Screening Technology & Research Center of Ophthalmology, Guangxi Academy of Medical Sciences & Department of Ophthalmology, The People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, 530021, China
| | - Mingyuan Zhang
- Guangxi Health Commission Key Laboratory of Ophthalmology and Related Systemic Diseases Artificial Intelligence Screening Technology & Research Center of Ophthalmology, Guangxi Academy of Medical Sciences & Department of Ophthalmology, The People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, 530021, China
| | - Fan Xu
- Guangxi Health Commission Key Laboratory of Ophthalmology and Related Systemic Diseases Artificial Intelligence Screening Technology & Research Center of Ophthalmology, Guangxi Academy of Medical Sciences & Department of Ophthalmology, The People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, 530021, China.
| | - Zhou Zhou
- Guangxi Health Commission Key Laboratory of Ophthalmology and Related Systemic Diseases Artificial Intelligence Screening Technology & Research Center of Ophthalmology, Guangxi Academy of Medical Sciences & Department of Ophthalmology, The People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, 530021, China.
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Low JY, Laiho M. Caveolae-Associated Molecules, Tumor Stroma, and Cancer Drug Resistance: Current Findings and Future Perspectives. Cancers (Basel) 2022; 14:cancers14030589. [PMID: 35158857 PMCID: PMC8833326 DOI: 10.3390/cancers14030589] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 01/21/2022] [Accepted: 01/22/2022] [Indexed: 02/04/2023] Open
Abstract
Simple Summary Cell membranes contain small invaginations called caveolae. They are a specialized lipid domain and orchestrate cellular signaling events, mechanoprotection, and lipid homeostasis. Formation of the caveolae depends on two classes of proteins, the caveolins and cavins, which form large complexes that allow their self-assembly into caveolae. Loss of either of these two proteins leads to distortion of the caveolae structure and disruption of many physiological processes that affect diseases of the muscle, metabolic states governing lipids, and the glucose balance as well as cancers. In cancers, the expression of caveolins and cavins is heterogenous, and they undergo alterations both in the tumors and the surrounding tumor microenvironment stromal cells. Remarkably, their expression and function has been associated with resistance to many cancer drugs. Here, we summarize the current knowledge of the resistance mechanisms and how this knowledge could be applied into the clinic in future. Abstract The discovery of small, “cave-like” invaginations at the plasma membrane, called caveola, has opened up a new and exciting research area in health and diseases revolving around this cellular ultrastructure. Caveolae are rich in cholesterol and orchestrate cellular signaling events. Within caveola, the caveola-associated proteins, caveolins and cavins, are critical components for the formation of these lipid rafts, their dynamics, and cellular pathophysiology. Their alterations underlie human diseases such as lipodystrophy, muscular dystrophy, cardiovascular disease, and diabetes. The expression of caveolins and cavins is modulated in tumors and in tumor stroma, and their alterations are connected with cancer progression and treatment resistance. To date, although substantial breakthroughs in cancer drug development have been made, drug resistance remains a problem leading to treatment failures and challenging translation and bench-to-bedside research. Here, we summarize the current progress in understanding cancer drug resistance in the context of caveola-associated molecules and tumor stroma and discuss how we can potentially design therapeutic avenues to target these molecules in order to overcome treatment resistance.
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Affiliation(s)
- Jin-Yih Low
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA;
- Correspondence: ; Tel.: +1-410-502-9748; Fax: +1-410-502-2821
| | - Marikki Laiho
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA;
- Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
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12
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Mohan AA, Tomaszewski WH, Haskell-Mendoza AP, Hotchkiss KM, Singh K, Reedy JL, Fecci PE, Sampson JH, Khasraw M. Targeting Immunometabolism in Glioblastoma. Front Oncol 2021; 11:696402. [PMID: 34222022 PMCID: PMC8242259 DOI: 10.3389/fonc.2021.696402] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Accepted: 05/26/2021] [Indexed: 12/11/2022] Open
Abstract
We have only recently begun to understand how cancer metabolism affects antitumor responses and immunotherapy outcomes. Certain immunometabolic targets have been actively pursued in other tumor types, however, glioblastoma research has been slow to exploit the therapeutic vulnerabilities of immunometabolism. In this review, we highlight the pathways that are most relevant to glioblastoma and focus on how these immunometabolic pathways influence tumor growth and immune suppression. We discuss hypoxia, glycolysis, tryptophan metabolism, arginine metabolism, 2-Hydroxyglutarate (2HG) metabolism, adenosine metabolism, and altered phospholipid metabolism, in order to provide an analysis and overview of the field of glioblastoma immunometabolism.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Mustafa Khasraw
- Preston Robert Tisch Brain Tumor Center at Duke, Department of Neurosurgery, Duke University Medical Center, Durham, NC, United States
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13
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Abstract
Caveolae are specialised and dynamic plasma membrane subdomains, involved in many cellular functions including endocytosis, signal transduction, mechanosensing and lipid storage, trafficking, and metabolism. Two protein families are indispensable for caveola formation and function, namely caveolins and cavins. Mutations of genes encoding these caveolar proteins cause serious pathological conditions such as cardiomyopathies, skeletal muscle diseases, and lipodystrophies. Deregulation of caveola-forming protein expression is associated with many types of cancers including prostate cancer. The distinct function of secretion of the prostatic fluid, and the unique metabolic phenotype of prostate cells relying on lipid metabolism as a main bioenergetic pathway further suggest a significant role of caveolae and caveolar proteins in prostate malignancy. Accumulating in vitro, in vivo, and clinical evidence showed the association of caveolin-1 with prostate cancer grade, stage, metastasis, and drug resistance. In contrast, cavin-1 was found to exhibit tumour suppressive roles. Studies on prostate cancer were the first to show the distinct function of the caveolar proteins depending on their localisation within the caveolar compartment or as cytoplasmic or secreted proteins. In this review, we summarise the roles of caveola-forming proteins in prostate cancer and the potential of exploiting them as therapeutic targets or biological markers.
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14
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Matthaeus C, Taraska JW. Energy and Dynamics of Caveolae Trafficking. Front Cell Dev Biol 2021; 8:614472. [PMID: 33692993 PMCID: PMC7939723 DOI: 10.3389/fcell.2020.614472] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Accepted: 12/21/2020] [Indexed: 12/19/2022] Open
Abstract
Caveolae are 70–100 nm diameter plasma membrane invaginations found in abundance in adipocytes, endothelial cells, myocytes, and fibroblasts. Their bulb-shaped membrane domain is characterized and formed by specific lipid binding proteins including Caveolins, Cavins, Pacsin2, and EHD2. Likewise, an enrichment of cholesterol and other lipids makes caveolae a distinct membrane environment that supports proteins involved in cell-type specific signaling pathways. Their ability to detach from the plasma membrane and move through the cytosol has been shown to be important for lipid trafficking and metabolism. Here, we review recent concepts in caveolae trafficking and dynamics. Second, we discuss how ATP and GTP-regulated proteins including dynamin and EHD2 control caveolae behavior. Throughout, we summarize the potential physiological and cell biological roles of caveolae internalization and trafficking and highlight open questions in the field and future directions for study.
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Affiliation(s)
- Claudia Matthaeus
- Biochemistry and Biophysics Center, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD, United States
| | - Justin W Taraska
- Biochemistry and Biophysics Center, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD, United States
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15
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Buwa N, Mazumdar D, Balasubramanian N. Caveolin1 Tyrosine-14 Phosphorylation: Role in Cellular Responsiveness to Mechanical Cues. J Membr Biol 2020; 253:509-534. [PMID: 33089394 DOI: 10.1007/s00232-020-00143-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 10/05/2020] [Indexed: 02/07/2023]
Abstract
The plasma membrane is a dynamic lipid bilayer that engages with the extracellular microenvironment and intracellular cytoskeleton. Caveolae are distinct plasma membrane invaginations lined by integral membrane proteins Caveolin1, 2, and 3. Caveolae formation and stability is further supported by additional proteins including Cavin1, EHD2, Pacsin2 and ROR1. The lipid composition of caveolar membranes, rich in cholesterol and phosphatidylserine, actively contributes to caveolae formation and function. Post-translational modifications of Cav1, including its phosphorylation of the tyrosine-14 residue (pY14Cav1) are vital to its function in and out of caveolae. Cells that experience significant mechanical stress are seen to have abundant caveolae. They play a vital role in regulating cellular signaling and endocytosis, which could further affect the abundance and distribution of caveolae at the PM, contributing to sensing and/or buffering mechanical stress. Changes in membrane tension in cells responding to multiple mechanical stimuli affects the organization and function of caveolae. These mechanical cues regulate pY14Cav1 levels and function in caveolae and focal adhesions. This review, along with looking at the mechanosensitive nature of caveolae, focuses on the role of pY14Cav1 in regulating cellular mechanotransduction.
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Affiliation(s)
- Natasha Buwa
- Indian Institute of Science Education and Research, Pune, Dr. Homi Bhabha Road, Pashan, Pune, 411008, India
| | - Debasmita Mazumdar
- Indian Institute of Science Education and Research, Pune, Dr. Homi Bhabha Road, Pashan, Pune, 411008, India
| | - Nagaraj Balasubramanian
- Indian Institute of Science Education and Research, Pune, Dr. Homi Bhabha Road, Pashan, Pune, 411008, India.
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16
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Bai L, Lyu Y, Shi G, Li K, Huang Y, Ma Y, Cong YS, Zhang L, Qin C. Polymerase I and transcript release factor transgenic mice show impaired function of hematopoietic stem cells. Aging (Albany NY) 2020; 12:20152-20162. [PMID: 33087586 PMCID: PMC7655181 DOI: 10.18632/aging.103729] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Accepted: 06/22/2020] [Indexed: 12/20/2022]
Abstract
The age-dependent decline in stem cell function plays a critical role in aging, although the molecular mechanisms remain unclear. PTRF/Cavin-1 is an essential component in the biogenesis and function of caveolae, which regulates cell proliferation, endocytosis, signal transduction and senescence. This study aimed to analyze the role of PTRF in hematopoietic stem cells (HSCs) senescence using PTRF transgenic mice. Flow cytometry was used to detect the frequency of immune cells and hematopoietic stem/progenitor cells (HSCs and HPCs). The results showed than the HSC compartment was significantly expanded in the bone marrow of PTRF transgenic mice compared to age-matched wild-type (WT) mice, and exhibited the senescent phenotype characterized by G1 cell cycle arrest, increased SA-β-Gal activity and high levels of reactive oxygen species (ROS). The PTRF-overexpressing HSCs also showed significantly lower self-renewal and ability to reconstitute hematopoiesis in vitro and in vivo. Real-time PCR was performed to analyze the expression levels of senescence-related genes. PTRF induced HSCs senescence via the ROS-p38-p16 and caveolin-1-p53-p21 pathways. Furthermore, the PTRF+cav-1-/- mice showed similar HSCs function as WT mice, indicating that PTRF induces senescence in HSCs partly through caveolin-1. Thus PTRF impaired HSCs aging partly via caveolin-1.
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Affiliation(s)
- Lin Bai
- NHC Key Laboratory of Human Disease Comparative Medicine, The Institute of Laboratory Animal Sciences, CAMS&PUMC, Beijing 100021, China.,Beijing Engineering Research Center for Experimental Animal Models of Human Critical Diseases, Beijing 100021, China
| | - Ying Lyu
- NHC Key Laboratory of Human Disease Comparative Medicine, The Institute of Laboratory Animal Sciences, CAMS&PUMC, Beijing 100021, China.,Beijing Engineering Research Center for Experimental Animal Models of Human Critical Diseases, Beijing 100021, China
| | - Guiying Shi
- NHC Key Laboratory of Human Disease Comparative Medicine, The Institute of Laboratory Animal Sciences, CAMS&PUMC, Beijing 100021, China.,Beijing Engineering Research Center for Experimental Animal Models of Human Critical Diseases, Beijing 100021, China
| | - Keya Li
- NHC Key Laboratory of Human Disease Comparative Medicine, The Institute of Laboratory Animal Sciences, CAMS&PUMC, Beijing 100021, China.,Beijing Engineering Research Center for Experimental Animal Models of Human Critical Diseases, Beijing 100021, China
| | - Yiying Huang
- NHC Key Laboratory of Human Disease Comparative Medicine, The Institute of Laboratory Animal Sciences, CAMS&PUMC, Beijing 100021, China.,Beijing Engineering Research Center for Experimental Animal Models of Human Critical Diseases, Beijing 100021, China
| | - Yuanwu Ma
- NHC Key Laboratory of Human Disease Comparative Medicine, The Institute of Laboratory Animal Sciences, CAMS&PUMC, Beijing 100021, China.,Beijing Engineering Research Center for Experimental Animal Models of Human Critical Diseases, Beijing 100021, China
| | - Yu-Sheng Cong
- Institute of Aging Research, Hangzhou Normal University School of Medicine, Hangzhou 310036, China
| | - Lianfeng Zhang
- NHC Key Laboratory of Human Disease Comparative Medicine, The Institute of Laboratory Animal Sciences, CAMS&PUMC, Beijing 100021, China.,Beijing Engineering Research Center for Experimental Animal Models of Human Critical Diseases, Beijing 100021, China
| | - Chuan Qin
- NHC Key Laboratory of Human Disease Comparative Medicine, The Institute of Laboratory Animal Sciences, CAMS&PUMC, Beijing 100021, China.,Beijing Engineering Research Center for Experimental Animal Models of Human Critical Diseases, Beijing 100021, China
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17
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Zhao Y, Wang Y, Zhao E, Tan Y, Geng B, Kang C, Li X. PTRF/CAVIN1, regulated by SHC1 through the EGFR pathway, is found in urine exosomes as a potential biomarker of ccRCC. Carcinogenesis 2020; 41:274-283. [PMID: 31605605 DOI: 10.1093/carcin/bgz147] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 08/07/2019] [Accepted: 08/20/2019] [Indexed: 01/10/2023] Open
Abstract
Polymerase I and transcript release factor (PTRF)/Cavin1 regulates RNA polymerase I during transcription and plays a critical role in endocytosis. Abnormal expressions of PTRF were detected in multiple cancers according to increasing research. PTRF has been showed to involve in the formation and secretion of exosomes and can be detected in the exosomes, which suggests that PTRF would be a potential biomarker for diagnosis of clear cell renal cell carcinoma (ccRCC) using urine samples. Approximately 50-90% of ccRCC cases suffered abnormal epidermal growth factor receptor (EGFR), which activates a variety of signaling pathways, including the mitogen-activated protein kinase/extracellular signal-regulated kinase and Phosphoinositide 3-Kinase/Akt pathway. According to bioinformatic analysis of gene expression arrays of kidney clear cell carcinoma from The Cancer Genome Atlas, we found SHC1 was significantly overexpressed in high-grade ccRCC and correlated to poor prognosis, and also SHC1 was annotated in extracellular matrix process, which was regulated by EGFR. Further studies showed that the expression of PTRF was regulated by SHC1 through EGFR-Phosphoinositide 3-Kinase/Akt pathway. PTRF was detected in the exosomes isolated from ccRCC patients' urine and ccRCC cancer cells culture medium. It suggested that the abnormal SHC1-increased PTRF, which is detected in exosomes from urine, would be a potential marker for ccRCC diagnose and treatment.
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Affiliation(s)
- Yubo Zhao
- Department of Urology, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Yunfei Wang
- Laboratory of Neuro-oncology, Tianjin Neurological Institute, Department of Neurosurgery, Tianjin Medical University General Hospital; Key Laboratory of Post-Neuroinjury Neuro-Repair and Regeneration in Central Nervous System, Ministry of Education and Tianjin City, Tianjin, China
| | - Enyang Zhao
- Department of Urology, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Yanli Tan
- Department of Pathology, Affiliated Hospital of Hebei University, Baoding, China
| | - Bo Geng
- Department of Urology, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Chunsheng Kang
- Laboratory of Neuro-oncology, Tianjin Neurological Institute, Department of Neurosurgery, Tianjin Medical University General Hospital; Key Laboratory of Post-Neuroinjury Neuro-Repair and Regeneration in Central Nervous System, Ministry of Education and Tianjin City, Tianjin, China
| | - Xuedong Li
- Department of Urology, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
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18
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Park PJ, Kim ST. Caveolae-Associated Protein 3 (Cavin-3) Influences Adipogenesis via TACE-Mediated Pref-1 Shedding. Int J Mol Sci 2020; 21:ijms21145000. [PMID: 32679831 PMCID: PMC7404391 DOI: 10.3390/ijms21145000] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 07/06/2020] [Accepted: 07/13/2020] [Indexed: 12/16/2022] Open
Abstract
Abnormal adipogenesis regulation is accompanied by a variety of metabolic dysfunctions and disorders. Caveolae play an important role in the regulation of fat production, modulated by caveolae-associated proteins (Cavin-1 to 4). Here, we investigated the role of Cavin-3 in lipogenesis and adipocyte differentiation, as the regulatory functions and roles of Cavin-3 in adipocytes are unknown. A Cavin-3 knockdown/overexpression stable cell line was established, and adipogenesis-related gene and protein expression changes were investigated by real-time quantitative PCR and Western blot analysis, respectively. Additionally, confocal immune-fluorescence microscopy was used to verify the intracellular position of the relevant factors. The results showed that Cavin-3 mRNA and protein expression were elevated, along with physiological factors such as lipid droplet formation, during adipogenesis. Cavin-3 silencing resulted in retarded adipocyte differentiation, and its overexpression accelerated this process. Furthermore, Cavin-3 knockdown resulted in decreased expression of adipogenesis-related genes, such as PPAR-γ, FAS, aP2, and Adipoq, whereas preadipocyte factor-1 (Pref-1) was markedly increased during adipocyte maturation. Overall, Cavin-3 influences caveolar stability and modulates the tumor necrosis factor-alpha-converting enzyme (TACE)-mediated Pref-1 shedding process in both mouse and human adipocytes. The Cavin-3-dependent shedding mechanism appears to be an important process in adipocyte maturation, providing a potential therapeutic target for obesity-related disorders.
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Affiliation(s)
- Phil June Park
- Bioscience Laboratory, AMOREPACIFIC R&D Center, 1920 Yonggu-daero, Giheung-gu, Yongin-si, Gyeonggi-do 17074, Korea
- Correspondence: (P.J.P.); (S.T.K.); Tel.: +82-31-280-5639 (P.J.P.); +82-55-320-4038 (S.T.K.)
| | - Sung Tae Kim
- Department of Pharmaceutical Engineering, Inje University, 197 Inje-ro, Gimhae-si, Gyeongsangnam-do 50834, Korea
- Correspondence: (P.J.P.); (S.T.K.); Tel.: +82-31-280-5639 (P.J.P.); +82-55-320-4038 (S.T.K.)
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19
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Low JY, Brennen WN, Meeker AK, Ikonen E, Simons BW, Laiho M. Stromal CAVIN1 Controls Prostate Cancer Microenvironment and Metastasis by Modulating Lipid Distribution and Inflammatory Signaling. Mol Cancer Res 2020; 18:1414-1426. [PMID: 32493699 DOI: 10.1158/1541-7786.mcr-20-0364] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 05/01/2020] [Accepted: 05/28/2020] [Indexed: 11/16/2022]
Abstract
Lipid uptake occurs through caveolae, plasma membrane invaginations formed by caveolins (CAV) and caveolae-associated protein 1 (CAVIN1). Genetic alterations of CAV1N1 and CAV1 modify lipid metabolism and underpin lipodystrophy syndromes. Lipids contribute to tumorigenesis by providing fuel to cancer metabolism and supporting growth and signaling. Tumor stroma promotes tumor proliferation, invasion, and metastasis, but how stromal lipids influence these processes remain to be defined. Here, we show that stromal CAVIN1 regulates lipid abundance in the prostate cancer microenvironment and suppresses metastasis. We show that depletion of CAVIN1 in prostate stromal cells markedly reduces their lipid droplet accumulation and increases inflammation. Stromal cells lacking CAVIN1 enhance prostate cancer cell migration and invasion. Remarkably, they increase lipid uptake and M2 inflammatory macrophage infiltration in the primary tumors and metastasis to distant sites. Our data support the concept that stromal cells contribute to prostate cancer aggressiveness by modulating lipid content and inflammation in the tumor microenvironment. IMPLICATIONS: This study showed that stromal CAVIN1 suppresses prostate cancer metastasis by modulating tumor microenvironment, lipid content, and inflammatory response.
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Affiliation(s)
- Jin-Yih Low
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - W Nathaniel Brennen
- Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Alan K Meeker
- Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, Maryland.,Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland.,Department of Urology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Elina Ikonen
- Faculty of Medicine, Anatomy and Stem Cells and Metabolism Research Program, University of Helsinki, Helsinki, Finland.,Minerva Foundation Institute for Medical Research, Helsinki, Finland
| | - Brian W Simons
- Center for Comparative Medicine, Baylor College of Medicine, Houston, Texas
| | - Marikki Laiho
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland. .,Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, Maryland
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20
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Wang L, Yang C, Wang Q, Liu Q, Wang Y, Zhou J, Li Y, Tan Y, Kang C. Homotrimer cavin1 interacts with caveolin1 to facilitate tumor growth and activate microglia through extracellular vesicles in glioma. Am J Cancer Res 2020; 10:6674-6694. [PMID: 32550897 PMCID: PMC7295042 DOI: 10.7150/thno.45688] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 04/16/2020] [Indexed: 02/07/2023] Open
Abstract
Background: Intercellular communication via extracellular vesicles (EVs) plays a critical role in glioma progression. However, little is known about the precise mechanism regulating EV secretion and function. Our previous study revealed that Cavin1 was positively correlated with malignancy grades of glioma patients, and that overexpressing Cavin1 in glioma cells enhanced the malignancy of nearby glioma cells via EVs. Methods: The current study used bioinformatics to design a variant Cavin1 (vCavin1) incapable of interacting with Caveolin1, and compared the effects of overexpressing Cavin1 and vCavin1 in glioma cells on EV production and function. Results: Remarkably, our results indicated that Cavin1 expression enhanced the secretion, uptake, and homing ability of glioma-derived EVs. EVs expressing Cavin1 promoted glioma growth in vitro and in vivo. In addition, Cavin1 expressing murine glioma cells recruited and activated microglia via EVs. However, vCavin1 neither was loaded onto EVs nor altered EV secretion and function. Conclusion: Our findings suggested that Cavin1-Caveolin1 interaction played a significant role in regulating production and function of glioma-EVs, and may act as a promising therapeutic target in gliomas that express high levels of Cavin1.
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21
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Lessons from cavin-1 deficiency. Biochem Soc Trans 2020; 48:147-154. [PMID: 31922193 DOI: 10.1042/bst20190380] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Revised: 12/12/2019] [Accepted: 12/18/2019] [Indexed: 01/19/2023]
Abstract
Caveolae have been implicated in a wide range of critical physiological functions. In the past decade, the dominant role of cavin-1 in caveolae formation has been established, and it has been recognized as another master regulator for caveolae biology. Human patients with cavin-1 mutations develop lipodystrophy and muscular dystrophy and have some major pathological dysfunctions in fat tissue, skeleton muscle, heart, lung and other organs. Cavin-1 deficiency animal models consistently show similar phenotypes. However, the underlying molecular mechanisms remain to be elucidated. Recent studies have suggested many possible pathways, including mechanosensing, stress response, signal transduction, exosome secretion, and potential functions in the nucleus. Many excellent and comprehensive review articles already exist on the topics of caveolae structure formation, caveolins, and their pathophysiological functions. We will focus on recent studies using cavin-1 deficiency models, to summarize the pathophysiological changes in adipose, muscle, and other organs, followed by a summary of mechanistic studies about the roles of cavin-1, which includes caveolae formation, ribosomal RNA transcription, mechanical sensing, stress response, and exosome secretion. Further studies may help to elucidate the exact underlying molecular mechanism to explain the pathological changes observed in cavin-1 deficient human patients and animal models, so potential new therapeutic strategies can be developed.
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22
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Hoa Chung L, Qi Y. Lipodystrophy - A Rare Condition with Serious Metabolic Abnormalities. Rare Dis 2020. [DOI: 10.5772/intechopen.88667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
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23
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Yeh HC, Margulis V, Singla N, Hernandez E, Panwar V, Woldu SL, Karam JA, Wood CG, Weizer AZ, Raman JD, Remzi M, Rioux-Leclercq N, Haitel A, Roscigno M, Bolenz C, Bensalah K, Li CC, Ke HL, Li WM, Lee HY, Rapoport LM, Lotan Y, Kapur P, Shariat SF, Hsieh JT, Wu WJ. PTRF independently predicts progression and survival in multiracial upper tract urothelial carcinoma following radical nephroureterectomy. Urol Oncol 2019; 38:496-505. [PMID: 31862213 DOI: 10.1016/j.urolonc.2019.11.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 11/22/2019] [Accepted: 11/25/2019] [Indexed: 01/04/2023]
Abstract
OBJECTIVES Polymerase I and transcript release factor (PTRF) has been implicated in cancer biology but its role in upper tract urothelial carcinoma (UTUC) is unknown. From a pilot transcriptome, we identified PTRF was significantly upregulated in high stage UTUC. Bladder cancer transcriptome from The Cancer Genome Atlas (TCGA) supported our finding and high PTRF level also predicted poor survival. We, therefore, investigated the correlation of PTRF with patients' clinicopathologic characteristics and outcomes in a multiracial UTUC cohort. MATERIALS AND METHODS By immunohistochemical staining, PTRF expression was determined using H-score. PTRF expression of 575 UTUCs from 8 institutions, including 118 Asians and 457 Caucasians, was compared with various clinicopathologic parameters. Human urothelial cancer cell lines were used to evaluate the level of PTRF protein and mRNA expression, and PTRF transcript level was assessed in fresh samples from 12 cases of the cohort. The impact of PTRF expression on disease progression, cancer-specific death and overall mortality was also examined. RESULTS High PTRF expression was significantly associated with multifocality (P = 0.023), high pathologic tumor stage (P < 0.00001), nonurothelial differentiation (P = 0.035), lymphovascular invasion (P = 0.003) and lymph node metastasis (P = 0.031). PTRF mRNA expression was also markedly increased in advanced stage UTUC (P = 0.0003). High PTRF expressing patients had consistently worse outcomes than patients with low PTRF expression regardless of demographic variation (all P < 0.005). In multivariate analysis, high PTRF expression was an independent predictor for progression-free survival (hazard ratio [HR] 1.70, 95% confidence interval [CI] 1.07-2.69, P = 0.025), cancer-specific survival (HR 2.09, 95% CI 1.28-3.42, P = 0.003), and overall survival (HR 2.04, 95% CI 1.33-3.14, P = 0.001). CONCLUSIONS Results indicate that PTRF is a predictive biomarker for progression and survival and an independent prognosticator of UTUC. Elevated PTRF could probably propel clinically aggressive disease and serve as a potential therapeutic target for UTUC.
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Affiliation(s)
- Hsin-Chih Yeh
- Department of Urology, Kaohsiung Municipal Ta-Tung Hospital, Kaohsiung, Taiwan; Department of Urology, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan; Department of Urology, School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan; Department of Urology, University of Texas Southwestern Medical Center, Dallas, TX
| | - Vitaly Margulis
- Department of Urology, University of Texas Southwestern Medical Center, Dallas, TX
| | - Nirmish Singla
- Department of Urology, University of Texas Southwestern Medical Center, Dallas, TX
| | - Elizabeth Hernandez
- Department of Urology, University of Texas Southwestern Medical Center, Dallas, TX
| | - Vandana Panwar
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX
| | - Solomon L Woldu
- Department of Urology, University of Texas Southwestern Medical Center, Dallas, TX
| | - Jose A Karam
- Department of Urology, MD Anderson Cancer Center, Houston, TX
| | | | - Alon Z Weizer
- Department of Urology, University of Michigan, Ann Arbor, MI
| | - Jay D Raman
- Division of Urology, Penn State Milton S. Hershey Medical Center, Hershey, PA
| | - Mesut Remzi
- Department of Urology, Medical University of Vienna, Vienna, Austria
| | | | - Andrea Haitel
- Department of Pathology, Medical University of Vienna, Vienna, Austria
| | - Marco Roscigno
- Department of Urology, Ospedali Riuniti of Bergamo, Bergamo, Italy
| | | | - Karim Bensalah
- Department of Urology, Centre Hospitalier Universitaire de Rennes, Rennes, France
| | - Ching-Chia Li
- Department of Urology, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan; Department of Urology, School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Hung-Lung Ke
- Department of Urology, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan; Department of Urology, School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Wei-Ming Li
- Department of Urology, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan; Department of Urology, School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Hsiang-Ying Lee
- Department of Urology, Kaohsiung Municipal Ta-Tung Hospital, Kaohsiung, Taiwan; Department of Urology, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan; Department of Urology, School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Leonid M Rapoport
- Institute for Urology and Reproductive Health, Sechenov University, Moscow, Russia
| | - Yair Lotan
- Department of Urology, University of Texas Southwestern Medical Center, Dallas, TX
| | - Payal Kapur
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX
| | - Shahrokh F Shariat
- Department of Urology, University of Texas Southwestern Medical Center, Dallas, TX; Department of Urology, Medical University of Vienna, Vienna, Austria; Institute for Urology and Reproductive Health, Sechenov University, Moscow, Russia
| | - Jer-Tsong Hsieh
- Department of Urology, University of Texas Southwestern Medical Center, Dallas, TX; Department of Biotechnology, Kaohsiung Medical University, Kaohsiung, Taiwan.
| | - Wen-Jeng Wu
- Department of Urology, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan; Department of Urology, School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan; Institute of Medical Science and Technology, National Sun Yat-sen University, Kaohsiung, Taiwan.
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24
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Hochreuter MY, Altıntaş A, Garde C, Emanuelli B, Kahn CR, Zierath JR, Vienberg S, Barrès R. Identification of two microRNA nodes as potential cooperative modulators of liver metabolism. Hepatol Res 2019; 49:1451-1465. [PMID: 31408567 PMCID: PMC6972499 DOI: 10.1111/hepr.13419] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 07/03/2019] [Accepted: 07/02/2019] [Indexed: 12/19/2022]
Abstract
AIM Hepatic insulin resistance is a hallmark of type 2 diabetes and non-alcoholic fatty liver disease. Dysregulation of microRNA (miRNA) expression in insulin-resistant livers might coordinate impaired hepatic metabolic function. Here, we aimed to discover miRNAs and their downstream targets involved in hepatic insulin resistance. METHODS We determined miRNA expression profiles by small RNA sequencing of two mouse models of impaired hepatic insulin action: high-fat diet-induced obesity and liver-specific insulin receptor knockout. Conversely, we assessed the hepatic miRNA expression profile after treatment with the antidiabetic hormone, fibroblast growth factor 21 (FGF21). Ontology analysis of predicted miRNA gene targets was performed to identify regulated gene pathways. Target enrichment analysis and miRNA mimic overexpression in vitro were used to identify unified protein targets of nodes of regulated miRNAs. RESULTS We identified an array of miRNA species regulated by impaired liver insulin action or after fibroblast growth factor 21 treatment. Ontology analysis of predicted miRNA gene targets identified pathways controlling hepatic energy metabolism and insulin sensitivity. We identified a node of two miRNAs downregulated in the livers of liver-specific insulin receptor knockout mice, miR-883b and miR-205, which positively regulate the expression of transcription factor zinc finger E-box-binding homeobox 1 (ZBED1). We found another node of two miRNAs upregulated in the livers of fibroblast growth factor 21-treated mice, miR-155-3p and miR-1968-5p, which canonically downregulates the caveola component, polymerase I and transcript release factor (PTRF), a gene previously implicated in hepatic energy metabolism. CONCLUSIONS This study identifies two nodes of coregulated miRNAs that might coordinately control hepatic energy metabolism in states of insulin resistance.
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Affiliation(s)
- Mette Yde Hochreuter
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Ali Altıntaş
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Christian Garde
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Brice Emanuelli
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - C. Ronald Kahn
- Section of Integrative Physiology and MetabolismJoslin Diabetes Center and Harvard Medical SchoolBostonMassachusettsUSA
| | - Juleen R. Zierath
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark,Department of Molecular Medicine and SurgeryKarolinska InstitutetStockholmSweden,Department of Physiology and PharmacologyKarolinska InstitutetStockholmSweden
| | | | - Romain Barrès
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
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25
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Identification of intracellular cavin target proteins reveals cavin-PP1alpha interactions regulate apoptosis. Nat Commun 2019; 10:3279. [PMID: 31332168 PMCID: PMC6646387 DOI: 10.1038/s41467-019-11111-1] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2018] [Accepted: 06/14/2019] [Indexed: 12/20/2022] Open
Abstract
Caveolae are specialized domains of the plasma membrane. Formation of these invaginations is dependent on the expression of Caveolin-1 or -3 and proteins of the cavin family. In response to stress, caveolae disassemble and cavins are released from caveolae, allowing cavins to potentially interact with intracellular targets. Here, we describe the intracellular (non-plasma membrane) cavin interactome using biotin affinity proteomics and mass spectrometry. We validate 47 potential cavin-interactor proteins using a cell-free expression system and protein-protein binding assays. These data, together with pathway analyses, reveal unknown roles for cavin proteins in metabolism and stress signaling. We validated the interaction between one candidate interactor protein, protein phosphatase 1 alpha (PP1α), and Cavin-1 and -3 and show that UV treatment causes release of Cavin3 from caveolae allowing interaction with, and inhibition of, PP1α. This interaction increases H2AX phosphorylation to stimulate apoptosis, identifying a pro-apoptotic signaling pathway from surface caveolae to the nucleus.
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26
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Wang H, Pilch PF, Liu L. Cavin-1/PTRF mediates insulin-dependent focal adhesion remodeling and ameliorates high-fat diet-induced inflammatory responses in mice. J Biol Chem 2019; 294:10544-10552. [PMID: 31126986 DOI: 10.1074/jbc.ra119.008824] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Revised: 05/20/2019] [Indexed: 11/06/2022] Open
Abstract
Cavin-1/polymerase I and transcript release factor (PTRF) is a requisite component of caveolae, small plasma membrane invaginations that are highly abundant in adipocytes. Cavin-1 is a dynamic molecule whose dissociation from caveolae plays an important role in mechanoprotection and rRNA synthesis. In the former situation, the acute dissociation of cavin-1 from caveolae allows cell membrane expansion that occurs upon insulin-aided lipid uptake into the fat cells. Cavin-1 dissociation from caveolae and membrane flattening alters the cytoskeleton and the interaction of plasma membrane proteins with the extracellular matrix through interactions with focal adhesion structures. Here, using cavin-1 knockout mice, subcellular fractionation, and immunoblotting methods, we addressed the relationship of cavin-1 with focal adhesion complexes following nutritional stimulation. We found that cavin-1 is acutely translocated to focal complex compartments upon insulin stimulation, where it regulates focal complex formation through an interaction with paxillin. We found that loss of cavin-1 impairs focal complex remodeling and focal adhesion formation and causes a mechanical stress response, concomitant with activation of proinflammatory and senescence/apoptosis pathways. We conclude that cavin-1 plays key roles in dynamic remodeling of focal complexes upon metabolic stimulation. This mechanism also underlies the crucial role of caveolae in the long-term healthy expansion of the adipocyte.
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Affiliation(s)
- Hong Wang
- From the Departments of Biochemistry
| | - Paul F Pilch
- From the Departments of Biochemistry.,Medicine, and
| | - Libin Liu
- From the Departments of Biochemistry, .,Pharmacology and Experimental Therapeutics, Boston University School of Medicine, Boston, Massachusetts 02118
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27
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Role of the Endocytosis of Caveolae in Intracellular Signaling and Metabolism. PROGRESS IN MOLECULAR AND SUBCELLULAR BIOLOGY 2019; 57:203-234. [PMID: 30097777 DOI: 10.1007/978-3-319-96704-2_8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Caveolae are 60-80 nm invaginated plasma membrane (PM) nanodomains, with a specific lipid and protein composition, which assist and regulate multiple processes in the plasma membrane-ranging from the organization of signalling complexes to the mechanical adaptation to changes in PM tension. However, since their initial descriptions, these structures have additionally been found tightly linked to internalization processes, mechanoadaptation, to the regulation of signalling events and of endosomal trafficking. Here, we review caveolae biology from this perspective, and its implications for cell physiology and disease.
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28
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Guo Q, Guan GF, Cheng W, Zou CY, Zhu C, Cheng P, Wu AH. Integrated profiling identifies caveolae-associated protein 1 as a prognostic biomarker of malignancy in glioblastoma patients. CNS Neurosci Ther 2018; 25:343-354. [PMID: 30311408 DOI: 10.1111/cns.13072] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2018] [Revised: 07/24/2018] [Accepted: 09/10/2018] [Indexed: 12/13/2022] Open
Abstract
AIMS Glioblastoma (GBM) is a lethal disease of the central nervous system with high mortality, and novel therapeutic targets and strategies for GBM are urgently needed. Caveolae-associated protein 1 (CAVIN1) is an essential caveolar component-encoding gene and has been poorly studied in glioma. To this end, in this study, we evaluated CAVIN1 expression in glioma tissue as well as the correlation between CAVIN1 expression and prognosis in glioma patients using the data collected from clinical samples or from the Cancer Genome Atlas (TCGA), Chinese Glioma Genome Atlas (CGGA), Rembrandt, and Gene Expression Omnibus (GEO) data sets. METHODS Survival analysis was performed with the Kaplan-Meier curve and log-rank test. The predictive role of CAVIN1 in progressive malignancy in glioma was evaluated by using a receiver operator characteristic (ROC) curve. Gene ontology (GO), Gene set enrichment analysis (GSEA), and gene set variation analysis (GSVA) methods were used to interpret the functions of CAVIN1 in GBM. RESULTS CAVIN1 expression was elevated in GBM compared with that in low-grade glioma and nontumor brain samples and was correlated with unfavorable outcomes in glioma patients. Additionally, CAVIN1 could serve as an independent predictive factor for progressive malignancy in GBM. Furthermore, CAVIN1 was associated with disrupted angiogenesis and immune response in the tumor microenvironment of GBM. CONCLUSIONS We identified CAVIN1 as a prognostic biomarker and potential target for developing novel therapeutic strategies against GBM.
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Affiliation(s)
- Qing Guo
- Department of Neurosurgery, The First Hospital of China Medical University, Shenyang, China
| | - Ge-Fei Guan
- Department of Neurosurgery, The First Hospital of China Medical University, Shenyang, China
| | - Wen Cheng
- Department of Neurosurgery, The First Hospital of China Medical University, Shenyang, China
| | - Cun-Yi Zou
- Department of Neurosurgery, The First Hospital of China Medical University, Shenyang, China
| | - Chen Zhu
- Department of Neurosurgery, The First Hospital of China Medical University, Shenyang, China
| | - Peng Cheng
- Department of Neurosurgery, The First Hospital of China Medical University, Shenyang, China
| | - An-Hua Wu
- Department of Neurosurgery, The First Hospital of China Medical University, Shenyang, China
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29
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Abstract
The plasma membrane of eukaryotic cells is not a simple sheet of lipids and proteins but is differentiated into subdomains with crucial functions. Caveolae, small pits in the plasma membrane, are the most abundant surface subdomains of many mammalian cells. The cellular functions of caveolae have long remained obscure, but a new molecular understanding of caveola formation has led to insights into their workings. Caveolae are formed by the coordinated action of a number of lipid-interacting proteins to produce a microdomain with a specific structure and lipid composition. Caveolae can bud from the plasma membrane to form an endocytic vesicle or can flatten into the membrane to help cells withstand mechanical stress. The role of caveolae as mechanoprotective and signal transduction elements is reviewed in the context of disease conditions associated with caveola dysfunction.
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Affiliation(s)
- Robert G. Parton
- Institute for Molecular Bioscience and Centre for Microscopy and Microanalysis, University of Queensland, Brisbane, Queensland 4060, Australia
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30
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Ni Y, Hao J, Hou X, Du W, Yu Y, Chen T, Wei Z, Li Y, Zhu F, Wang S, Liang R, Li D, Lu Y, Liao K, Li B, Shi G. Dephosphorylated Polymerase I and Transcript Release Factor Prevents Allergic Asthma Exacerbations by Limiting IL-33 Release. Front Immunol 2018; 9:1422. [PMID: 29977243 PMCID: PMC6021487 DOI: 10.3389/fimmu.2018.01422] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Accepted: 06/07/2018] [Indexed: 01/12/2023] Open
Abstract
Background Asthma is a chronic inflammatory disease characterized by airway inflammation and airway hyperresponsiveness (AHR). IL-33 is considered as one of the most critical molecules in asthma pathogenesis. IL-33 is stored in nucleus and passively released during necrosis. But little is known about whether living cells can release IL-33 and how this process is regulated. Objective We sought to investigate the role of polymerase I and transcript release factor (PTRF) in IL-33 release and asthma pathogenesis. Methods Ovalbumin (OVA)-induced asthma model in PTRF+/- mice were employed to dissect the role of PTRF in vivo. Then, further in vitro experiments were carried out to unwind the potential mechanism involved. Results In OVA asthma model with challenge phase, PTRF+/- mice showed a greater airway hyper-reaction, with an intense airway inflammation and more eosinophils in bronchoalveolar lavage fluid (BALF). Consistently, more acute type 2 immune response in lung and a higher IL-33 level in BALF were found in PTRF+/- mice. In OVA asthma model without challenge phase, airway inflammation and local type 2 immune responses were comparable between control mice and PTRF+/- mice. Knockdown of PTRF in 16HBE led to a significantly increased level of IL-33 in cell culture supernatants in response to LPS or HDM. Immunoprecipitation assay clarified Y158 as the major phosphorylation site of PTRF, which was also critical for the interaction of IL-33 and PTRF. Overexpression of dephosphorylated mutant Y158F of PTRF sequestered IL-33 in nucleus together with PTRF and limited IL-33 extracellular secretion. Conclusion Partial loss of PTRF led to a greater AHR and potent type 2 immune responses during challenge phase of asthma model, without influencing the sensitization phase. PTRF phosphorylation status determined subcellular location of PTRF and, therefore, regulated IL-33 release.
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Affiliation(s)
- Yingmeng Ni
- Department of Pulmonary and Critical Care Medicine, Rui Jin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Institute of Respiratory Diseases, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jimin Hao
- Department of Pulmonary and Critical Care Medicine, Rui Jin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Institute of Respiratory Diseases, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xiaoxia Hou
- Department of Pulmonary and Critical Care Medicine, Rui Jin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Institute of Respiratory Diseases, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Wei Du
- Department of Pulmonary and Critical Care Medicine, Rui Jin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Institute of Respiratory Diseases, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Youchao Yu
- Department of Pulmonary and Critical Care Medicine, Rui Jin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Institute of Respiratory Diseases, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Tiantian Chen
- Department of Pulmonary and Critical Care Medicine, Rui Jin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Institute of Respiratory Diseases, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Zhuang Wei
- Laboratory of Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Yangyang Li
- Department of Immunology and Microbiology, Shanghai Institute of Immunology, Shanghai Jiao Tong University School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Fuxiang Zhu
- Department of Immunology and Microbiology, Shanghai Institute of Immunology, Shanghai Jiao Tong University School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Shuaiwei Wang
- Department of Immunology and Microbiology, Shanghai Institute of Immunology, Shanghai Jiao Tong University School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Rui Liang
- Department of Immunology and Microbiology, Shanghai Institute of Immunology, Shanghai Jiao Tong University School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Dan Li
- Department of Immunology and Microbiology, Shanghai Institute of Immunology, Shanghai Jiao Tong University School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Yue Lu
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Kan Liao
- Laboratory of Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Bin Li
- Department of Immunology and Microbiology, Shanghai Institute of Immunology, Shanghai Jiao Tong University School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Guochao Shi
- Department of Pulmonary and Critical Care Medicine, Rui Jin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Institute of Respiratory Diseases, Shanghai Jiao Tong University School of Medicine, Shanghai, China
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31
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Huang K, Fang C, Yi K, Liu X, Qi H, Tan Y, Zhou J, Li Y, Liu M, Zhang Y, Yang J, Zhang J, Li M, Kang C. The role of PTRF/Cavin1 as a biomarker in both glioma and serum exosomes. Theranostics 2018; 8:1540-1557. [PMID: 29556340 PMCID: PMC5858166 DOI: 10.7150/thno.22952] [Citation(s) in RCA: 96] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Accepted: 12/05/2017] [Indexed: 12/30/2022] Open
Abstract
Exosomes play critical roles in intercellular communication in both nearby and distant cells in individuals and organs. Polymerase I and transcript release factor (PTRF), also known as Cavin1, has previously been described as a critical factor in caveola formation, and aberrant PTRF expression has been reported in various malignancies. However, the function of PTRF in tumor progression remains controversial, and its role in glioma is poorly understood. In this study, we report that PTRF is associated with malignancy grade and poor prognosis in glioma patients. Our previous study using two proteomics methods, tandem mass tag (TMT) and data-independent acquisition (DIA), showed that EGFRvIII overexpression increased PTRF expression at the protein level. In contrast, blocking PI3K and AKT using LY294002 and MK-2206, respectively, decreased PTRF expression, showing that PTRF is regulated in the EGFR/PI3K/AKT pathway. ChIP-PCR analysis showed that PTRF is transcriptionally regulated by the H3K4me3 and H3K27me3 modifications. Furthermore, PTRF overexpression increased exosome secretion and induced cell growth in vitro. More importantly, overexpressing PTRF induced the malignancy of nearby cells in vivo, suggesting that PTRF alters the microenvironment through intercellular communication via exosomes. Furthermore, analysis of clinical samples showed a positive correlation between tumor grade and PTRF expression in both tumor tissues and exosomes isolated from blood harvested from glioma patients, and PTRF expression in exosomes isolated from the sera of GBM patients was decreased after surgery. In conclusion, PTRF serves as a promising biomarker in both tumor samples and serum exosomes, thus facilitating the detection of glioma and potentially serving as a therapeutic target for glioblastoma multiforme.
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Affiliation(s)
- Kai Huang
- Tianjin Neurological Institute, Key Laboratory of Post-neurotrauma Neuro-repair and Regeneration in Central Nervous System, Ministry of Education and Tianjin City, Tianjin 300052, China
| | - Chuan Fang
- Department of Neurosurgery, Tianjin Medical University General Hospital, Tianjin 300052, China
- Department of Neurosurgery, Hebei University Affiliated Hospital, Baoding 071000, China
| | - Kaikai Yi
- Tianjin Neurological Institute, Key Laboratory of Post-neurotrauma Neuro-repair and Regeneration in Central Nervous System, Ministry of Education and Tianjin City, Tianjin 300052, China
| | - Xing Liu
- Beijing Neurosurgical Institute, Capital Medical University,Beijing,100050,China
| | - Hongzhao Qi
- Tianjin Key Laboratory of Composite and Functional Materials, School of Materials Science and Engineering, Tianjin University , Tianjin 300072, China
| | - Yanli Tan
- College of Fundamental Medicine, Hebei University, Baoding 071000, China
| | - Junhu Zhou
- Tianjin Neurological Institute, Key Laboratory of Post-neurotrauma Neuro-repair and Regeneration in Central Nervous System, Ministry of Education and Tianjin City, Tianjin 300052, China
| | - Ying Li
- Tianjin Neurological Institute, Key Laboratory of Post-neurotrauma Neuro-repair and Regeneration in Central Nervous System, Ministry of Education and Tianjin City, Tianjin 300052, China
| | - Mingyang Liu
- Department of Medicine, Department of Surgery, the University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA
| | - Yuqing Zhang
- Department of Medicine, Department of Surgery, the University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA
| | - Jingxuan Yang
- Department of Medicine, Department of Surgery, the University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA
| | - Jianning Zhang
- Department of Neurosurgery, Tianjin Medical University General Hospital, Tianjin 300052, China
| | - Min Li
- Department of Medicine, Department of Surgery, the University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA
| | - Chunsheng Kang
- Tianjin Neurological Institute, Key Laboratory of Post-neurotrauma Neuro-repair and Regeneration in Central Nervous System, Ministry of Education and Tianjin City, Tianjin 300052, China
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32
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Cai Y, Ruan J, Yao X, Zhao L, Wang B. MicroRNA-187 modulates epithelial-mesenchymal transition by targeting PTRF in non-small cell lung cancer. Oncol Rep 2017; 37:2787-2794. [PMID: 28393200 DOI: 10.3892/or.2017.5548] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Accepted: 12/14/2016] [Indexed: 11/06/2022] Open
Abstract
MicroRNAs (miRNAs) that negatively regulate gene expression play a key role in the development and progression of cancer. Aberrant expression of hsa-miR-187 (miR-187) has been reported in various malignancies. However, the function of miR-187 in tumor progression remains controversial and its role in non-small cell lung cancer (NSCLC) is poorly understood. In the present study, the role of miR-187 in the progression of NSCLC was investigated. Our results revealed that miR-187 was frequently upregulated in NSCLC tissues and cells. Furthermore, ectopic introduction of miR-187 promoted cell migration, whereas miR-187 inhibitor had the contrary effect in NSCLC cells. Of significance, miR-187 induced epithelial-mesenchymal transition (EMT), which plays a pivotal role in the initiation of metastasis and activated mitogen-activated protein kinase (MAPK) and phosphatidylinositol-3-kinase/protein kinase B (PI3K/AKT) pathways. Polymerase I and transcript release factor (PTRF) was identified as a direct target of miR-187 in the promotion of the migration of NSCLC cells. Restored expression of PTRF neutralized the promoting effect of miR-187 on cell migration and EMT of NSCLC cells. Collectively, our data highlight the pivotal role of miR-187 in the progression of NSCLC, indicating this factor as a potential candidate in molecular cancer therapy.
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Affiliation(s)
- Yanjun Cai
- Department of Oncology, Jinan Clinical College of the Second Military Medical University, Jinan, Shandong, P.R. China
| | - Jian Ruan
- Cancer Center, Traditional Chinese Medicine-Integrated Hospital, Southern Medical University, Guangzhou, Guangdong, P.R. China
| | - Xueqing Yao
- Department of General Surgery, Guangdong General Hospital, Guangdong Academy of Medical Science, Guangzhou, Guangdong, P.R. China
| | - Liang Zhao
- Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong, P.R. China
| | - Baocheng Wang
- Department of Oncology, Jinan Clinical College of the Second Military Medical University, Jinan, Shandong, P.R. China
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33
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Kaakinen M, Reichelt ME, Ma Z, Ferguson C, Martel N, Porrello ER, Hudson JE, Thomas WG, Parton RG, Headrick JP. Cavin-1 deficiency modifies myocardial and coronary function, stretch responses and ischaemic tolerance: roles of NOS over-activity. Basic Res Cardiol 2017; 112:24. [PMID: 28343262 DOI: 10.1007/s00395-017-0613-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Revised: 02/09/2017] [Accepted: 03/09/2017] [Indexed: 02/07/2023]
Abstract
Caveolae and associated cavin and caveolins may govern myocardial function, together with responses to mechanical and ischaemic stresses. Abnormalities in these proteins are also implicated in different cardiovascular disorders. However, specific roles of the cavin-1 protein in cardiac and coronary responses to mechanical/metabolic perturbation remain unclear. We characterised cardiovascular impacts of cavin-1 deficiency, comparing myocardial and coronary phenotypes and responses to stretch and ischaemia-reperfusion in hearts from cavin-1 +/+ and cavin-1 -/- mice. Caveolae and caveolins 1 and 3 were depleted in cavin-1 -/- hearts. Cardiac ejection properties in situ were modestly reduced in cavin-1 -/- mice. While peak contractile performance in ex vivo myocardium from cavin-1 -/- and cavin-1 +/+ mice was comparable, intrinsic beating rate, diastolic stiffness and Frank-Starling behaviour (stretch-dependent diastolic and systolic forces) were exaggerated in cavin-1 -/- hearts. Increases in stretch-dependent forces were countered by NOS inhibition (100 µM L-NAME), which exposed negative inotropy in cavin-1 -/- hearts, and were mimicked by 100 µM nitroprusside. In contrast, chronotropic differences appeared largely NOS-independent. Cavin-1 deletion also induced NOS-dependent coronary dilatation, ≥3-fold prolongation of reactive hyperaemic responses, and exaggerated pressure-dependence of coronary flow. Stretch-dependent efflux of lactate dehydrogenase and cardiac troponin I was increased and induction of brain natriuretic peptide and c-Fos inhibited in cavin-1 -/- hearts, while ERK1/2 phospho-activation was preserved. Post-ischaemic dysfunction and damage was also exaggerated in cavin-1 -/- hearts. Diverse effects of cavin-1 deletion reveal important roles in both NOS-dependent and -independent control of cardiac and coronary functions, together with governing sarcolemmal fragility and myocardial responses to stretch and ischaemia.
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Affiliation(s)
- Mika Kaakinen
- Oulu Center for Cell-Matrix Research, Faculty of Biochemistry and Molecular Medicine, Biocenter Oulu, University of Oulu, Oulu, Finland.,Institute for Molecular Biosciences, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Melissa E Reichelt
- School of Biomedical Sciences, The University of Queensland, Brisbane, Australia
| | - Zhibin Ma
- School of Biomedical Sciences, The University of Queensland, Brisbane, Australia
| | - Charles Ferguson
- Institute for Molecular Biosciences, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Nick Martel
- Institute for Molecular Biosciences, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Enzo R Porrello
- School of Biomedical Sciences, The University of Queensland, Brisbane, Australia
| | - James E Hudson
- School of Biomedical Sciences, The University of Queensland, Brisbane, Australia
| | - Walter G Thomas
- School of Biomedical Sciences, The University of Queensland, Brisbane, Australia
| | - Robert G Parton
- Institute for Molecular Biosciences, The University of Queensland, St Lucia, QLD, 4072, Australia.
| | - John P Headrick
- School of Medical Science, Griffith University, Southport, QLD, 4217, Australia.
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34
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Liu L, Pilch PF. PTRF/Cavin-1 promotes efficient ribosomal RNA transcription in response to metabolic challenges. eLife 2016; 5. [PMID: 27528195 PMCID: PMC4987143 DOI: 10.7554/elife.17508] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Accepted: 07/18/2016] [Indexed: 01/25/2023] Open
Abstract
Ribosomal RNA transcription mediated by RNA polymerase I represents the rate-limiting step in ribosome biogenesis. In eukaryotic cells, nutrients and growth factors regulate ribosomal RNA transcription through various key factors coupled to cell growth. We show here in mature adipocytes, ribosomal transcription can be acutely regulated in response to metabolic challenges. This acute response is mediated by PTRF (polymerase I transcription and release factor, also known as cavin-1), which has previously been shown to play a critical role in caveolae formation. The caveolae–independent rDNA transcriptional role of PTRF not only explains the lipodystrophy phenotype observed in PTRF deficient mice and humans, but also highlights its crucial physiological role in maintaining adipocyte allostasis. Multiple post-translational modifications of PTRF provide mechanistic bases for its regulation. The role of PTRF in ribosomal transcriptional efficiency is likely relevant to many additional physiological situations of cell growth and organismal metabolism. DOI:http://dx.doi.org/10.7554/eLife.17508.001 Obesity can cause several other health conditions to develop. Type 2 diabetes is one such condition, which arises in part because fat cells become unable to store excess fats. This makes certain tissues in the body less sensitive to the hormone insulin, and so the individual is less able to adapt to changing nutrient levels. Without treatment or a change in lifestyle, this insulin resistance may develop into diabetes. However, “healthy obese” individuals also exist, who can accommodate an overabundance of fat without developing insulin resistance and diabetes. Some forms of rare genetic disorders called lipodystrophies, which result in an almost complete lack of body fat, can also lead to type 2 diabetes. This raises the question of whether lipodystrophy and obesity share some common mechanisms that cause fat cells to trigger insulin resistance. One possible player in such mechanisms is a protein called PTRF. In rare cases, individuals with lipodystrophy lack this protein, and mice that have been engineered to lack PTRF also largely lack body fat and develop insulin resistance. Fat cells can respond rapidly to changes in nutrients during feeding or fasting, and to do so, they must produce new proteins. Structures called ribosomes, which are made up of proteins and ribosomal RNA, build proteins; thus when the cell needs to make new proteins, it also has to produce more ribosomes. PTRF is thought to play a role in ribosome production, but it is not clear how it does so. Liu and Pilch analyzed normal mice as well as those that lacked the PTRF protein. This revealed that in response to cycles of fasting and feeding, PTRF increases the production of ribosomal RNA in fat cells, enabling the cells to produce more proteins. By contrast, the fat cells of mice that lack PTRF have much lower levels of ribosomal RNA and proteins. Liu and Pilch then examined mouse fat cells that were grown in the laboratory. Exposing these cells to insulin caused phosphate groups to be attached to the PTRF proteins inside the cells. This modification caused PTRF to move into the cell’s nucleus, where it increased the production of ribosomal RNA. Overall, the results show that fat cells that lack PTRF are unable to produce the proteins that they need to deal with changing nutrient levels, leading to an increased likelihood of diabetes. The next steps are to investigate the mechanism by which PTRF is modified, and to see whether the mechanisms uncovered in this study also apply to humans. DOI:http://dx.doi.org/10.7554/eLife.17508.002
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Affiliation(s)
- Libin Liu
- Department of Biochemistry, Boston University School of Medicine, Boston, United States
| | - Paul F Pilch
- Department of Biochemistry, Boston University School of Medicine, Boston, United States.,Department of Medicine, Boston University School of Medicine, Boston, United States
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Porrua O, Boudvillain M, Libri D. Transcription Termination: Variations on Common Themes. Trends Genet 2016; 32:508-522. [DOI: 10.1016/j.tig.2016.05.007] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2016] [Revised: 05/28/2016] [Accepted: 05/31/2016] [Indexed: 11/29/2022]
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Kovtun O, Tillu VA, Ariotti N, Parton RG, Collins BM. Cavin family proteins and the assembly of caveolae. J Cell Sci 2016; 128:1269-78. [PMID: 25829513 DOI: 10.1242/jcs.167866] [Citation(s) in RCA: 151] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Caveolae are an abundant feature of the plasma membrane in many cells. Until recently, they were generally considered to be membrane invaginations whose formation primarily driven by integral membrane proteins called caveolins. However, the past decade has seen the emergence of the cavin family of peripheral membrane proteins as essential coat components and regulators of caveola biogenesis. In this Commentary, we summarise recent data on the role of cavins in caveola formation, highlighting structural studies that provide new insights into cavin coat assembly. In mammals, there are four cavin family members that associate through homo- and hetero-oligomerisation to form distinct subcomplexes on caveolae, which can be released into the cell in response to stimuli. Studies from several labs have provided a better understanding of cavin stoichiometry and the molecular basis for their oligomerisation, as well as identifying interactions with membrane phospholipids that may be important for caveola function. We propose a model in which coincident, low-affinity electrostatically controlled protein-protein and protein-lipid interactions allow the formation of caveolae, generating a meta-stable structure that can respond to plasma membrane stress by release of cavins.
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Affiliation(s)
- Oleksiy Kovtun
- The University of Queensland, Institute for Molecular Bioscience, Brisbane St Lucia, QLD, 4072, Australia
| | - Vikas A Tillu
- The University of Queensland, Institute for Molecular Bioscience, Brisbane St Lucia, QLD, 4072, Australia
| | - Nicholas Ariotti
- The University of Queensland, Institute for Molecular Bioscience, Brisbane St Lucia, QLD, 4072, Australia
| | - Robert G Parton
- The University of Queensland, Institute for Molecular Bioscience, Brisbane St Lucia, QLD, 4072, Australia Centre for Microscopy and Microanalysis, St. Lucia, QLD, 4072, Australia
| | - Brett M Collins
- The University of Queensland, Institute for Molecular Bioscience, Brisbane St Lucia, QLD, 4072, Australia
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Reijm EA, Sieuwerts AM, Smid M, Vries JBD, Mostert B, Onstenk W, Peeters D, Dirix LY, Seynaeve CM, Jager A, de Jongh FE, Hamberg P, van Galen A, Kraan J, Jansen MPHM, Gratama JW, Foekens JA, Martens JWM, Berns EMJJ, Sleijfer S. An 8-gene mRNA expression profile in circulating tumor cells predicts response to aromatase inhibitors in metastatic breast cancer patients. BMC Cancer 2016; 16:123. [PMID: 26892682 PMCID: PMC4759736 DOI: 10.1186/s12885-016-2155-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Accepted: 02/10/2016] [Indexed: 12/29/2022] Open
Abstract
Background Molecular characterization of circulating tumor cells (CTC) is promising for personalized medicine. We aimed to identify a CTC gene expression profile predicting outcome to first-line aromatase inhibitors in metastatic breast cancer (MBC) patients. Methods: CTCs were isolated from 78 MBC patients before treatment start. mRNA expression levels of 96 genes were measured by quantitative reverse transcriptase polymerase chain reaction. After applying predefined exclusion criteria based on lack of sufficient RNA quality and/or quantity, the data from 45 patients were used to construct a gene expression profile to predict poor responding patients, defined as disease progression or death <9 months, by a leave-one-out cross validation. Results Of the 45 patients, 19 were clinically classified as poor responders. To identify them, the 75 % most variable genes were used to select genes differentially expressed between good and poor responders. An 8-gene CTC predictor was significantly associated with outcome (Hazard Ratio [HR] 4.40, 95 % Confidence Interval [CI]: 2.17–8.92, P < 0.001). This predictor identified poor responding patients with a sensitivity of 63 % and a positive predictive value of 75 %, while good responding patients were correctly predicted in 85 % of the cases. In multivariate Cox regression analysis, including CTC count at baseline, the 8-gene CTC predictor was the only factor independently associated with outcome (HR 4.59 [95 % CI: 2.11–9.56], P < 0.001). This 8-gene signature was not associated with outcome in a group of 71 MBC patients treated with systemic treatments other than AI. Conclusions An 8-gene CTC predictor was identified which discriminates good and poor outcome to first-line aromatase inhibitors in MBC patients. Although results need to be validated, this study underscores the potential of molecular characterization of CTCs. Electronic supplementary material The online version of this article (doi:10.1186/s12885-016-2155-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Esther A Reijm
- Department of Medical Oncology and Cancer Genomics Netherlands, Erasmus MC - Cancer Institute, Erasmus University Medical Center, Room He 116, P.O. Box 2040, Rotterdam, 3000 CA, The Netherlands
| | - Anieta M Sieuwerts
- Department of Medical Oncology and Cancer Genomics Netherlands, Erasmus MC - Cancer Institute, Erasmus University Medical Center, Room He 116, P.O. Box 2040, Rotterdam, 3000 CA, The Netherlands
| | - Marcel Smid
- Department of Medical Oncology and Cancer Genomics Netherlands, Erasmus MC - Cancer Institute, Erasmus University Medical Center, Room He 116, P.O. Box 2040, Rotterdam, 3000 CA, The Netherlands
| | - Joan Bolt-de Vries
- Department of Medical Oncology and Cancer Genomics Netherlands, Erasmus MC - Cancer Institute, Erasmus University Medical Center, Room He 116, P.O. Box 2040, Rotterdam, 3000 CA, The Netherlands
| | - Bianca Mostert
- Department of Medical Oncology and Cancer Genomics Netherlands, Erasmus MC - Cancer Institute, Erasmus University Medical Center, Room He 116, P.O. Box 2040, Rotterdam, 3000 CA, The Netherlands
| | - Wendy Onstenk
- Department of Medical Oncology and Cancer Genomics Netherlands, Erasmus MC - Cancer Institute, Erasmus University Medical Center, Room He 116, P.O. Box 2040, Rotterdam, 3000 CA, The Netherlands
| | - Dieter Peeters
- Translational Cancer Research Unit, Oncology Center GZA Hospitals Sint-Augustinus and Department of Oncology, University of Antwerp, Antwerp, Belgium
| | - Luc Y Dirix
- Translational Cancer Research Unit, Oncology Center GZA Hospitals Sint-Augustinus and Department of Oncology, University of Antwerp, Antwerp, Belgium
| | - Caroline M Seynaeve
- Department of Medical Oncology and Cancer Genomics Netherlands, Erasmus MC - Cancer Institute, Erasmus University Medical Center, Room He 116, P.O. Box 2040, Rotterdam, 3000 CA, The Netherlands
| | - Agnes Jager
- Department of Medical Oncology and Cancer Genomics Netherlands, Erasmus MC - Cancer Institute, Erasmus University Medical Center, Room He 116, P.O. Box 2040, Rotterdam, 3000 CA, The Netherlands
| | - Felix E de Jongh
- Department of Internal Medicine, Ikazia Hospital, Rotterdam, The Netherlands
| | - Paul Hamberg
- Department of Internal Medicine, Sint Franciscus Gasthuis, Rotterdam, The Netherlands
| | - Anne van Galen
- Department of Medical Oncology and Cancer Genomics Netherlands, Erasmus MC - Cancer Institute, Erasmus University Medical Center, Room He 116, P.O. Box 2040, Rotterdam, 3000 CA, The Netherlands
| | - Jaco Kraan
- Department of Medical Oncology and Cancer Genomics Netherlands, Erasmus MC - Cancer Institute, Erasmus University Medical Center, Room He 116, P.O. Box 2040, Rotterdam, 3000 CA, The Netherlands
| | - Maurice P H M Jansen
- Department of Medical Oncology and Cancer Genomics Netherlands, Erasmus MC - Cancer Institute, Erasmus University Medical Center, Room He 116, P.O. Box 2040, Rotterdam, 3000 CA, The Netherlands
| | - Jan W Gratama
- Department of Medical Oncology and Cancer Genomics Netherlands, Erasmus MC - Cancer Institute, Erasmus University Medical Center, Room He 116, P.O. Box 2040, Rotterdam, 3000 CA, The Netherlands
| | - John A Foekens
- Department of Medical Oncology and Cancer Genomics Netherlands, Erasmus MC - Cancer Institute, Erasmus University Medical Center, Room He 116, P.O. Box 2040, Rotterdam, 3000 CA, The Netherlands
| | - John W M Martens
- Department of Medical Oncology and Cancer Genomics Netherlands, Erasmus MC - Cancer Institute, Erasmus University Medical Center, Room He 116, P.O. Box 2040, Rotterdam, 3000 CA, The Netherlands
| | - Els M J J Berns
- Department of Medical Oncology and Cancer Genomics Netherlands, Erasmus MC - Cancer Institute, Erasmus University Medical Center, Room He 116, P.O. Box 2040, Rotterdam, 3000 CA, The Netherlands
| | - Stefan Sleijfer
- Department of Medical Oncology and Cancer Genomics Netherlands, Erasmus MC - Cancer Institute, Erasmus University Medical Center, Room He 116, P.O. Box 2040, Rotterdam, 3000 CA, The Netherlands.
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Low JY, D. Nicholson H. The up-stream regulation of polymerase-1 and transcript release factor(PTRF/Cavin-1) in prostate cancer: an epigenetic analysis. AIMS MOLECULAR SCIENCE 2016. [DOI: 10.3934/molsci.2016.3.466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Cheng CY, Tu WL, Wang SH, Tang PC, Chen CF, Chen HH, Lee YP, Chen SE, Huang SY. Annotation of Differential Gene Expression in Small Yellow Follicles of a Broiler-Type Strain of Taiwan Country Chickens in Response to Acute Heat Stress. PLoS One 2015; 10:e0143418. [PMID: 26587838 PMCID: PMC4654548 DOI: 10.1371/journal.pone.0143418] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Accepted: 11/04/2015] [Indexed: 12/19/2022] Open
Abstract
This study investigated global gene expression in the small yellow follicles (6-8 mm diameter) of broiler-type B strain Taiwan country chickens (TCCs) in response to acute heat stress. Twelve 30-wk-old TCC hens were divided into four groups: control hens maintained at 25°C and hens subjected to 38°C acute heat stress for 2 h without recovery (H2R0), with 2-h recovery (H2R2), and with 6-h recovery (H2R6). Small yellow follicles were collected for RNA isolation and microarray analysis at the end of each time point. Results showed that 69, 51, and 76 genes were upregulated and 58, 15, 56 genes were downregulated after heat treatment of H2R0, H2R2, and H2R6, respectively, using a cutoff value of two-fold or higher. Gene ontology analysis revealed that these differentially expressed genes are associated with the biological processes of cell communication, developmental process, protein metabolic process, immune system process, and response to stimuli. Upregulation of heat shock protein 25, interleukin 6, metallopeptidase 1, and metalloproteinase 13, and downregulation of type II alpha 1 collagen, discoidin domain receptor tyrosine kinase 2, and Kruppel-like factor 2 suggested that acute heat stress induces proteolytic disintegration of the structural matrix and inflamed damage and adaptive responses of gene expression in the follicle cells. These suggestions were validated through gene expression, using quantitative real-time polymerase chain reaction. Functional annotation clarified that interleukin 6-related pathways play a critical role in regulating acute heat stress responses in the small yellow follicles of TCC hens.
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Affiliation(s)
- Chuen-Yu Cheng
- Department of Animal Science, National Chung Hsing University, Taichung, Taiwan
| | - Wei-Lin Tu
- Department of Animal Science, National Chung Hsing University, Taichung, Taiwan
| | - Shih-Han Wang
- Department of Animal Science, National Chung Hsing University, Taichung, Taiwan
| | - Pin-Chi Tang
- Department of Animal Science, National Chung Hsing University, Taichung, Taiwan
- Agricultural Biotechnology Center, National Chung Hsing University, Taichung, Taiwan
- Center for the Integrative and Evolutionary Galliformes Genomics, iEGG Center, National Chung Hsing University, Taichung, Taiwan
| | - Chih-Feng Chen
- Department of Animal Science, National Chung Hsing University, Taichung, Taiwan
- Agricultural Biotechnology Center, National Chung Hsing University, Taichung, Taiwan
- Center for the Integrative and Evolutionary Galliformes Genomics, iEGG Center, National Chung Hsing University, Taichung, Taiwan
| | - Hsin-Hsin Chen
- Department of Veterinary Medicine, National Chung Hsing University, Taichung, Taiwan
| | - Yen-Pai Lee
- Department of Animal Science, National Chung Hsing University, Taichung, Taiwan
| | - Shuen-Ei Chen
- Department of Animal Science, National Chung Hsing University, Taichung, Taiwan
- Agricultural Biotechnology Center, National Chung Hsing University, Taichung, Taiwan
- Center for the Integrative and Evolutionary Galliformes Genomics, iEGG Center, National Chung Hsing University, Taichung, Taiwan
- * E-mail: (SEC); (SYH)
| | - San-Yuan Huang
- Department of Animal Science, National Chung Hsing University, Taichung, Taiwan
- Agricultural Biotechnology Center, National Chung Hsing University, Taichung, Taiwan
- Center for the Integrative and Evolutionary Galliformes Genomics, iEGG Center, National Chung Hsing University, Taichung, Taiwan
- Center of Nanoscience and Nanotechnology, National Chung Hsing University, Taichung, Taiwan
- * E-mail: (SEC); (SYH)
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Tillu VA, Kovtun O, McMahon KA, Collins BM, Parton RG. A phosphoinositide-binding cluster in cavin1 acts as a molecular sensor for cavin1 degradation. Mol Biol Cell 2015; 26:3561-9. [PMID: 26269585 PMCID: PMC4603927 DOI: 10.1091/mbc.e15-06-0359] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Accepted: 08/06/2015] [Indexed: 11/30/2022] Open
Abstract
Cavin1 degradation is primarily mediated by the ubiquitin proteasome system. The phosphoinositide-binding region in cavin1 acts as a molecular switch for cavin1 degradation upon release of cavins in cytosol. This mechanism may help to maintain low levels of free cytosolic cavins at steady state. Caveolae are abundant surface organelles implicated in a range of cellular processes. Two classes of proteins work together to generate caveolae: integral membrane proteins termed caveolins and cytoplasmic coat proteins called cavins. Caveolae respond to membrane stress by releasing cavins into the cytosol. A crucial aspect of this model is tight regulation of cytosolic pools of cavin under resting conditions. We now show that a recently identified region of cavin1 that can bind phosphoinositide (PI) lipids is also a major site of ubiquitylation. Ubiquitylation of lysines within this site leads to rapid proteasomal degradation. In cells that lack caveolins and caveolae, cavin1 is cytosolic and rapidly degraded as compared with cells in which cavin1 is associated with caveolae. Membrane stretching causes caveolar disassembly, release of cavin complexes into the cytosol, and increased proteasomal degradation of wild-type cavin1 but not mutant cavin1 lacking the major ubiquitylation site. Release of cavin1 from caveolae thus leads to exposure of key lysine residues in the PI-binding region, acting as a trigger for cavin1 ubiquitylation and down-regulation. This mutually exclusive PI-binding/ubiquitylation mechanism may help maintain low levels of cytosolic cavin1 in resting cells, a prerequisite for cavins acting as signaling modules following release from caveolae.
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Affiliation(s)
- Vikas A Tillu
- Institute for Molecular Bioscience, University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Oleksiy Kovtun
- Institute for Molecular Bioscience, University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Kerrie-Ann McMahon
- Institute for Molecular Bioscience, University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Brett M Collins
- Institute for Molecular Bioscience, University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Robert G Parton
- Institute for Molecular Bioscience, University of Queensland, St. Lucia, Queensland 4072, Australia Centre for Microscopy and Microanalysis, University of Queensland, St. Lucia, Queensland 4072, Australia
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Chettimada S, Yang J, Moon HG, Jin Y. Caveolae, caveolin-1 and cavin-1: Emerging roles in pulmonary hypertension. World J Respirol 2015; 5:126-134. [PMID: 28529892 PMCID: PMC5438095 DOI: 10.5320/wjr.v5.i2.126] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Revised: 02/25/2015] [Accepted: 06/16/2015] [Indexed: 02/06/2023] Open
Abstract
Caveolae are flask-shaped invaginations of cell membrane that play a significant structural and functional role. Caveolae harbor a variety of signaling molecules and serve to receive, concentrate and transmit extracellular signals across the membrane. Caveolins are the main structural proteins residing in the caveolae. Caveolins and another category of newly identified caveolae regulatory proteins, named cavins, are not only responsible for caveolae formation, but also interact with signaling complexes in the caveolae and regulate transmission of signals across the membrane. In the lung, two of the three caveolin isoforms, i.e., cav-1 and -2, are expressed ubiquitously. Cavin protein family is composed of four proteins, named cavin-1 (or PTRF for polymerase I and transcript release factor), cavin-2 (or SDPR for serum deprivation protein response), cavin-3 (or SRBC for sdr-related gene product that binds to-c-kinase) and cavin-4 (or MURC for muscle restricted coiled-coiled protein or cavin-4). All the caveolin and cavin proteins are essential regulators for caveolae dynamics. Recently, emerging evidence suggest that caveolae and its associated proteins play crucial roles in development and progression of pulmonary hypertension. The focus of this review is to outline and discuss the contrast in alteration of cav-1 (cav-1),-2 and cavin-1 (PTRF) expression and downstream signaling mechanisms between human and experimental models of pulmonary hypertension.
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Low JY, Nicholson HD. Epigenetic modifications of caveolae associated proteins in health and disease. BMC Genet 2015; 16:71. [PMID: 26112043 PMCID: PMC4482180 DOI: 10.1186/s12863-015-0231-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Accepted: 06/15/2015] [Indexed: 02/06/2023] Open
Abstract
Caveolae are small, “omega-shaped” invaginations at the plasma membrane of the cell which are involved in a variety of processes including cholesterol transport, potocytosis and cell signalling. Within caveolae there are caveolae-associated proteins, and changes in expression of these molecules have been described to play a role in the pathophysiology of various diseases including cancer and cardiovascular disease. Evidence is beginning to accumulate that epigenetic processes may regulate the expression of these caveolae related genes, and hence contribute to disease progression. Here, we summarize the current knowledge of the role of epigenetic modification in regulating the expression of these caveolae related genes and how this relates to changes in cellular physiology and in health and disease.
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Affiliation(s)
- Jin-Yih Low
- Department of Anatomy, Otago School of Medical Sciences, University of Otago, P.O. Box 913, Dunedin, 9054, New Zealand.
| | - Helen D Nicholson
- Department of Anatomy, Otago School of Medical Sciences, University of Otago, P.O. Box 913, Dunedin, 9054, New Zealand.
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Cavin-1: caveolae-dependent signalling and cardiovascular disease. Biochem Soc Trans 2015; 42:284-8. [PMID: 24646232 DOI: 10.1042/bst20130270] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Caveolae are curved lipid raft regions rich in cholesterol and sphingolipids found abundantly in vascular endothelial cells, adipocytes, smooth muscle cells and fibroblasts. They are multifunctional organelles with roles in clathrin-independent endocytosis, cholesterol transport, mechanosensing and signal transduction. Caveolae provide an environment where multiple receptor signalling components are sequestered, clustered and compartmentalized for efficient signal transduction. Many of these receptors, including cytokine signal transducer gp130 (glycoprotein 130), are mediators of chronic inflammation during atherogenesis. Subsequently, disruption of these organelles is associated with a broad range of disease states including cardiovascular disease and cancer. Cavin-1 is an essential peripheral component of caveolae that stabilizes caveolin-1, the main structural/integral membrane protein of caveolae. Caveolin-1 is an essential regulator of eNOS (endothelial nitric oxide synthase) and its disruption leads to endothelial dysfunction which initiates a range of cardiovascular and pulmonary disorders. Although dysfunctional cytokine signalling is also a hallmark of cardiovascular disease, knowledge of caveolae-dependent cytokine signalling is lacking as is the role of cavin-1 independent of caveolae. The present review introduces caveolae, their structural components, the caveolins and cavins, their regulation by cAMP, and their potential role in cardiovascular disease.
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Cavin-1 and Caveolin-1 are both required to support cell proliferation, migration and anchorage-independent cell growth in rhabdomyosarcoma. J Transl Med 2015; 95:585-602. [PMID: 25822667 DOI: 10.1038/labinvest.2015.45] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Revised: 01/26/2015] [Accepted: 02/27/2015] [Indexed: 12/17/2022] Open
Abstract
Rhabdomyosarcoma (RMS) is a childhood soft tissue tumor with broad expression of markers that are typically found in skeletal muscle. Cavin-1 is a recently discovered protein actively cooperating with Caveolin-1 (Cav-1) in the morphogenesis of caveolae and whose role in cancer is drawing increasing attention. Using a combined in silico and in vitro analysis here we show that Cavin-1 is expressed in myogenic RMS tumors as well as in human and primary mouse RMS cultures, exhibiting a broad subcellular localization, ranging from nuclei and cytosol to plasma membrane. In particular, the coexpression and plasma membrane interaction between Cavin-1 and Cav-1 characterized the proliferation of human and mouse RMS cell cultures, while a downregulation of their expression levels was observed during the myogenic differentiation. Knockdown of Cavin-1 or Cav-1 in the human RD and RH30 cells led to impairment of cell proliferation and migration. Moreover, loss of Cavin-1 in RD cells impaired the anchorage-independent cell growth in soft agar. While the loss of Cavin-1 did not affect the Cav-1 protein levels in RMS cells, Cav-1 overexpression and knockdown triggered a rise or depletion of Cavin-1 protein levels in RD cells, respectively, in turn reflecting on increased or decreased cell proliferation, migration and anchorage-independent cell growth. Collectively, these data indicate that the interaction between Cavin-1 and Cav-1 underlies the cell growth and migration in myogenic tumors.
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Shvets E, Bitsikas V, Howard G, Hansen CG, Nichols BJ. Dynamic caveolae exclude bulk membrane proteins and are required for sorting of excess glycosphingolipids. Nat Commun 2015; 6:6867. [PMID: 25897946 PMCID: PMC4410672 DOI: 10.1038/ncomms7867] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Accepted: 03/06/2015] [Indexed: 12/19/2022] Open
Abstract
Caveolae have long been implicated in endocytosis. Recent data question this link, and in the absence of specific cargoes the potential cellular function of caveolar endocytosis remains unclear. Here we develop new tools, including doubly genome-edited cell lines, to assay the subcellular dynamics of caveolae using tagged proteins expressed at endogenous levels. We find that around 5% of the cellular pool of caveolae is present on dynamic endosomes, and is delivered to endosomes in a clathrin-independent manner. Furthermore, we show that caveolae are indeed likely to bud directly from the plasma membrane. Using a genetically encoded tag for electron microscopy and ratiometric light microscopy, we go on to show that bulk membrane proteins are depleted within caveolae. Although caveolae are likely to account for only a small proportion of total endocytosis, cells lacking caveolae show fundamentally altered patterns of membrane traffic when loaded with excess glycosphingolipid. Altogether, these observations support the hypothesis that caveolar endocytosis is specialized for transport of membrane lipid.
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Affiliation(s)
- Elena Shvets
- MRC-LMB, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | | | | | - Carsten Gram Hansen
- Sanford Consortium for Regenerative Medicine UCSD, 2880 Torrey Pines Scenic Drive, La Jolla, California 92037, USA
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Yokomori H, Ando W, Yoshimura K, Yamazaki H, Takahashi Y, Oda M. Increases in endothelial caveolin-1 and cavins correlate with cirrhosis progression. Micron 2015; 76:52-61. [PMID: 26086560 DOI: 10.1016/j.micron.2015.03.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Revised: 03/18/2015] [Accepted: 03/18/2015] [Indexed: 01/13/2023]
Abstract
BACKGROUND AND AIMS Caveolin-1 is associated with flat caveolar domains, invaginated smooth plasmalemmal vesicles, and caveolae. Polymerase 1 and transcript release factor (PTRF) (cavin 1) and serum deprivation protein response (SDPR) (cavin 2) are required for the invagination of caveolae, and PRKCDBP (protein kinase C, delta-binding protein; cavin 3) is required for caveolae budding to form caveolar vesicles. To investigate whether cavins are involved in hepatic sinusoidal angiogenesis and remodeling during progression to cirrhosis, normal control liver specimens and early and late cirrhotic liver specimens were studied. MATERIALS AND METHODS Cavin-1, cavin-2, and cavin-3 proteins and their gene expression were examined using immunohistochemistry (IHC), Western blotting, and laser capture microdissection (LCM)-polymerase chain reaction (PCR) during progression of cirrhosis caused by hepatitis C. According to the perfusion, fixation methods were designed to reevaluate the precise ultrastructural localizations and changes of cavin-1 and cavin-2 expression on liver sinusoidal endothelial cells (LSECs) facing the sinusoidal blood flow. RESULTS For IHC, cavin-1 and cavin-2 expressions were found to be upregulated in small angiogenic LSECs with collagen deposition in the perisinusoidal space as well as in the vascular endothelial cells of the remarkably proliferated portal venules, hepatic arterioles, and arterial capillaries within the fibrotic septa of late-stage cirrhotic liver. Cavin-3 was mainly localized in large vessels, and it was detected only scantly on the central vein and hepatic sinusoids in the control liver. In late-stage cirrhotic liver, the intensity of cavin-3 was enhanced mainly on proliferative large vessels in regenerated nodules and in the peripheral regions of nodules and fibrous septa. On conducting immunoelectron microscopy, in the control liver tissue, cavin-1 was found to be localized on the caveolae of hepatic arterial and portal venous endothelial cells, but it was scantly localized on hepatic sinusoidal lining cells, and cavin-2 was found mainly on vesicles in LSECs. In the cirrhotic liver tissue, aberrant cavin-1 and cavin-2 expressions were observed on caveolae-like structures in LSECs. Significant overexpressions of cavin-1 at the protein and messenger RNA (mRNA) levels in a cirrhotic liver were demonstrated by Western blotting and LCM-PCR. CONCLUSIONS Cavin-1 and cavin-2 are strongly expressed within caveolae-like structures and associated vesicles within LSECs of the hepatitis C-related cirrhotic liver. Cavin-1 would play a critical role in regulating aspects of caveolin-1 in LSECs. Moreover, these findings suggest a direct association of cavin-1 and cavin-2 with the process of differentiation and transformation of LSECs inducing hepatic sinusoidal capillarization related to the progression of cirrhosis.
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Affiliation(s)
- Hiroaki Yokomori
- Department of Internal Medicine, Kitasato University Medical Center, Saitama, Japan.
| | - Wataru Ando
- Department of Pharmaceutical Science, Kitasato University, Tokyo, Japan
| | - Kazunori Yoshimura
- Department of Rehabilitation, Nihon Institute of Medical Science, Saitama, Japan
| | - Hitoshi Yamazaki
- Department of Pathology, Kitasato University Medical Center, Saitama, Japan
| | | | - Masaya Oda
- Organized Center of Clinical Medicine, International University of Health and Welfare, Tokyo, Japan
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Xu L, Guo R, Xie Y, Ma M, Ye R, Liu X. Caveolae: molecular insights and therapeutic targets for stroke. Expert Opin Ther Targets 2015; 19:633-50. [PMID: 25639269 DOI: 10.1517/14728222.2015.1009446] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
INTRODUCTION Caveolae are specialized plasma membrane micro-invaginations of most mammalian cell types. The organization and function of caveolae are carried out by their coat proteins, caveolins and adaptor proteins, cavins. Caveolae/caveolins physically interact with membrane-associated signaling molecules and function in cholesterol incorporation, signaling transduction and macromolecular transport/permeability. AREAS COVERED Recent investigations have implicated a check-and-balance role of caveolae in the pathophysiology of cerebral ischemia. Caveolin knockout mice displayed exacerbated ischemic injury, whereas caveolin peptide exerted remarkable protection against ischemia/reperfusion injury. This review attempts to provide a comprehensive synopsis of how caveolae/caveolins modulate blood-brain barrier permeability, pro-survival signaling, angiogenesis and neuroinflammation, and how this may contribute to a better understanding of the participation of caveolae in ischemic cascade. The role of caveolin in the preconditioning-induced tolerance against ischemia is also discussed. EXPERT OPINION Caveolae represent a novel target for cerebral ischemia. It remains open how to manipulate caveolin expression in a practical way to recapitulate the beneficial therapeutic outcomes. Caveolin peptides and associated antagomirs may be efficacious and deserve further investigations for their potential benefits for stroke.
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Affiliation(s)
- Lili Xu
- Department of Neurology, Jinling Hospital, Medical School of Nanjing University , Nanjing 210002 , China
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The N-terminal leucine-zipper motif in PTRF/cavin-1 is essential and sufficient for its caveolae-association. Biochem Biophys Res Commun 2014; 456:750-6. [PMID: 25514038 DOI: 10.1016/j.bbrc.2014.12.035] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Accepted: 12/08/2014] [Indexed: 01/28/2023]
Abstract
PTRF/cavin-1 is a protein of two lives. Its reported functions in ribosomal RNA synthesis and in caveolae formation happen in two different cellular locations: nucleus vs. plasma membrane. Here, we identified that the N-terminal leucine-zipper motif in PTRF/cavin-1 was essential for the protein to be associated with caveolae in plasma membrane. It could counteract the effect of nuclear localization sequence in the molecule (AA 235-251). Deletion of this leucine-zipper motif from PTRF/cavin-1 caused the mutant to be exclusively localized in nuclei. The fusion of this leucine-zipper motif with histone 2A, which is a nuclear protein, could induce the fusion protein to be exported from nucleus. Cell migration was greatly inhibited in PTRF/cavin-1(-/-) mouse embryonic fibroblasts (MEFs). The inhibited cell motility could only be rescued by exogenous cavin-1 but not the leucine-zipper motif deleted cavin-1 mutant. Plasma membrane dynamics is an important factor in cell motility control. Our results suggested that the membrane dynamics in cell migration is affected by caveolae associated PTRF/cavin-1.
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Méndez-Giménez L, Rodríguez A, Balaguer I, Frühbeck G. Role of aquaglyceroporins and caveolins in energy and metabolic homeostasis. Mol Cell Endocrinol 2014; 397:78-92. [PMID: 25008241 DOI: 10.1016/j.mce.2014.06.017] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Revised: 06/25/2014] [Accepted: 06/26/2014] [Indexed: 12/23/2022]
Abstract
Aquaglyceroporins and caveolins are submicroscopic integral membrane proteins that are particularly abundant in many mammalian cells. Aquaglyceroporins (AQP3, AQP7, AQP9 and AQP10) encompass a subfamily of aquaporins that allow the movement of water, but also of small solutes, such as glycerol, across cell membranes. Glycerol constitutes an important metabolite as a substrate for de novo synthesis of triacylglycerols and glucose as well as an energy substrate to produce ATP via the mitochondrial oxidative phosphorylation. In this sense, the control of glycerol influx/efflux in metabolic organs by aquaglyceroporins plays a crucial role with the dysregulation of these glycerol channels being associated with metabolic diseases, such as obesity, insulin resistance, non-alcoholic fatty liver disease and cardiac hypertrophy. On the other hand, caveolae have emerged as relevant plasma membrane sensors implicated in a wide range of cellular functions, including endocytosis, apoptosis, cholesterol homeostasis, proliferation and signal transduction. Caveolae-coating proteins, namely caveolins and cavins, can act as scaffolding proteins within caveolae by concentrating signaling molecules involved in free fatty acid and cholesterol uptake, proliferation, insulin signaling or vasorelaxation, among others. The importance of caveolae in whole-body homeostasis is highlighted by the link between homozygous mutations in genes encoding caveolins and cavins with metabolic diseases, such as lipodystrophy, dyslipidemia, muscular dystrophy and insulin resistance in rodents and humans. The present review focuses on the role of aquaglyceroporins and caveolins on lipid and glucose metabolism, insulin secretion and signaling, energy production and cardiovascular homeostasis, outlining their potential relevance in the development and treatment of metabolic diseases.
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Affiliation(s)
- Leire Méndez-Giménez
- Metabolic Research Laboratory, Clínica Universidad de Navarra, Pamplona, Spain; CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Instituto de Salud Carlos III, Pamplona, Spain
| | - Amaia Rodríguez
- Metabolic Research Laboratory, Clínica Universidad de Navarra, Pamplona, Spain; CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Instituto de Salud Carlos III, Pamplona, Spain.
| | - Inmaculada Balaguer
- Metabolic Research Laboratory, Clínica Universidad de Navarra, Pamplona, Spain
| | - Gema Frühbeck
- Metabolic Research Laboratory, Clínica Universidad de Navarra, Pamplona, Spain; CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Instituto de Salud Carlos III, Pamplona, Spain; Department of Endocrinology and Nutrition, Clínica Universidad de Navarra, Pamplona, Spain.
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