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Hu Y, Ge K, Du Y. Paeoniflorin alleviates TGF-β2-mediated extracellular matrix remodeling and oxidative stress in human trabecular meshwork cells. Int Ophthalmol 2024; 44:229. [PMID: 38795168 DOI: 10.1007/s10792-024-02917-0] [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: 03/27/2023] [Accepted: 12/24/2023] [Indexed: 05/27/2024]
Abstract
BACKGROUND The multifunctional profibrotic cytokine transforming growth factor-beta2 (TGF-β2) is implicated in the pathophysiology of primary open angle glaucoma. Paeoniflorin (PAE) is a monoterpene glycoside with multiple pharmacological efficacies, such as antioxidant, anti-fibrotic, and anti-inflammatory properties. Studies have demonstrated that paeoniflorin protects human corneal epithelial cells, retinal pigment epithelial cells, and retinal microglia from damage. Here, the biological role of PAE in TGF-β2-dependent remodeling of the extracellular matrix (ECM) within the trabecular meshwork (TM) microenvironment. METHODS Primary or transformed (GTM3) human TM (HTM) cells conditioned in serum-free media were incubated with TGF-β2 (5 ng/mL). PAE (300 μM) was added to serum-starved confluent cultures of HTM cells for 2 h, followed by incubation with TGF-β2 for 22 h. SB-431542, a TGF-β receptor inhibitor (10 μM), was used as a positive control. The levels of intracellular ROS were evaluated by CellROX green dye. Western blotting was used to measure the levels of TGF-β2/Smad2/3 signaling-related molecules. Collagen 1α1, collagen 4α1, and connective tissue growth factor (CTGF) expression was evaluated by RT-qPCR. Immunofluorescence assay was conducted to measure collagen I/IV expression in HTM cells. Phalloidin staining assay was conducted for evaluating F-actin stress fiber formation in the cells. RESULTS PAE attenuated TGF-β2-induced oxidative stress and suppressed TGF-β2-induced Smad2/3 signaling in primary or transformed HTM cells. Additionally, PAE repressed TGF-β2-induced upregulation of collagen 1α1, collagen 4α1, and CTGF expression and reduced TGF-β2-mediated collagen I/IV expression and of F-actin stress fiber formation in primary or transformed HTM cells. CONCLUSION PAE alleviates TGF-β2-induced ECM deposition and oxidative stress in HTM cells through inactivation of Smad2/3 signaling.
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Affiliation(s)
- Yongmei Hu
- Department of Ophthalmology, The First People's Hospital of Jiangxia District, Wuhan, No.1 Wenhua Avenue, Zhifang Street, Jiangxia District, Wuhan, 430200, China
| | - Kui Ge
- Department of Ophthalmology, The First People's Hospital of Jiangxia District, Wuhan, No.1 Wenhua Avenue, Zhifang Street, Jiangxia District, Wuhan, 430200, China
| | - Yan Du
- Department of Ophthalmology, The First People's Hospital of Jiangxia District, Wuhan, No.1 Wenhua Avenue, Zhifang Street, Jiangxia District, Wuhan, 430200, China.
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Yuan Y, Li P, Li J, Zhao Q, Chang Y, He X. Protein lipidation in health and disease: molecular basis, physiological function and pathological implication. Signal Transduct Target Ther 2024; 9:60. [PMID: 38485938 PMCID: PMC10940682 DOI: 10.1038/s41392-024-01759-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Revised: 12/31/2023] [Accepted: 01/24/2024] [Indexed: 03/18/2024] Open
Abstract
Posttranslational modifications increase the complexity and functional diversity of proteins in response to complex external stimuli and internal changes. Among these, protein lipidations which refer to lipid attachment to proteins are prominent, which primarily encompassing five types including S-palmitoylation, N-myristoylation, S-prenylation, glycosylphosphatidylinositol (GPI) anchor and cholesterylation. Lipid attachment to proteins plays an essential role in the regulation of protein trafficking, localisation, stability, conformation, interactions and signal transduction by enhancing hydrophobicity. Accumulating evidence from genetic, structural, and biomedical studies has consistently shown that protein lipidation is pivotal in the regulation of broad physiological functions and is inextricably linked to a variety of diseases. Decades of dedicated research have driven the development of a wide range of drugs targeting protein lipidation, and several agents have been developed and tested in preclinical and clinical studies, some of which, such as asciminib and lonafarnib are FDA-approved for therapeutic use, indicating that targeting protein lipidations represents a promising therapeutic strategy. Here, we comprehensively review the known regulatory enzymes and catalytic mechanisms of various protein lipidation types, outline the impact of protein lipidations on physiology and disease, and highlight potential therapeutic targets and clinical research progress, aiming to provide a comprehensive reference for future protein lipidation research.
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Affiliation(s)
- Yuan Yuan
- Department of Gastroenterology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Peiyuan Li
- Department of Gastroenterology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jianghui Li
- Department of Gastroenterology, Zhongnan Hospital of Wuhan University, Wuhan, China
- Hubei Clinical Center and Key Laboratory of Intestinal and Colorectal Diseases, Wuhan, China
| | - Qiu Zhao
- Department of Gastroenterology, Zhongnan Hospital of Wuhan University, Wuhan, China.
- Hubei Clinical Center and Key Laboratory of Intestinal and Colorectal Diseases, Wuhan, China.
| | - Ying Chang
- Department of Gastroenterology, Zhongnan Hospital of Wuhan University, Wuhan, China.
- Hubei Clinical Center and Key Laboratory of Intestinal and Colorectal Diseases, Wuhan, China.
| | - Xingxing He
- Department of Gastroenterology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
- Department of Gastroenterology, Zhongnan Hospital of Wuhan University, Wuhan, China.
- Hubei Clinical Center and Key Laboratory of Intestinal and Colorectal Diseases, Wuhan, China.
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Stubbs EB. Determining Isoprenoid-Facilitated Monomeric GTPase Turnover in Primary Human Trabecular Meshwork Cultures. Methods Mol Biol 2024; 2816:101-115. [PMID: 38977592 DOI: 10.1007/978-1-0716-3902-3_10] [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] [Indexed: 07/10/2024]
Abstract
Members of the Rho family of small monomeric GTPases regulate a plethora of critical cellular functions including gene expression, cell cycle progression, and the dynamic modeling of the actin cytoskeleton. Diversity among Rho family members is derived, in part, from variations in their subcellular distribution. Localization of newly synthesized (naïve) Rho proteins to target subcellular compartments is largely governed by lipid modifications, including posttranslational prenylation. Here, using well-established and widely available contemporary methodologies, detailed protocols by which to semiquantitatively evaluate the functional consequence of posttranslational prenylation in human trabecular meshwork cells are described. We propose the novel concept that posttranslational prenylation itself is a key regulator of mammalian Rho GTPase protein expression and turnover.
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Affiliation(s)
- Evan B Stubbs
- Research Service, Department of Veterans Affairs, Edward Hines Jr. VA Hospital, Hines, IL, USA.
- Department of Ophthalmology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL, USA.
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Tsumagari K, Isobe Y, Ishihama Y, Seita J, Arita M, Imami K. Application of Liquid-Liquid Extraction for N-terminal Myristoylation Proteomics. Mol Cell Proteomics 2023; 22:100677. [PMID: 37949301 PMCID: PMC10696250 DOI: 10.1016/j.mcpro.2023.100677] [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: 05/15/2023] [Revised: 10/11/2023] [Accepted: 11/07/2023] [Indexed: 11/12/2023] Open
Abstract
Proteins can be modified by lipids in various ways, for example, by myristoylation, palmitoylation, farnesylation, and geranylgeranylation-these processes are collectively referred to as lipidation. Current chemical proteomics using alkyne lipids has enabled the identification of lipidated protein candidates but does not identify endogenous lipidation sites and is not readily applicable to in vivo systems. Here, we introduce a proteomic methodology for global analysis of endogenous protein N-terminal myristoylation sites that combines liquid-liquid extraction of hydrophobic lipidated peptides with liquid chromatography-tandem mass spectrometry using a gradient program of acetonitrile in the high concentration range. We applied this method to explore myristoylation sites in HeLa cells and identified a total of 75 protein N-terminal myristoylation sites, which is more than the number of high-confidence myristoylated proteins identified by myristic acid analog-based chemical proteomics. Isolation of myristoylated peptides from HeLa digests prepared with different proteases enabled the identification of different myristoylated sites, extending the coverage of N-myristoylome. Finally, we analyzed in vivo myristoylation sites in mouse tissues and found that the lipidation profile is tissue-specific. This simple method (not requiring chemical labeling or affinity purification) should be a promising tool for global profiling of protein N-terminal myristoylation.
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Affiliation(s)
- Kazuya Tsumagari
- Proteome Homeostasis Research Unit, RIKEN Center for Integrative Medical Sciences, Yokohama, Kanagawa, Japan; Laboratory for Metabolomics, RIKEN Center for Integrative Medical Sciences, Yokohama, Kanagawa, Japan; Laboratory for Integrative Genomics, RIKEN Center for Integrative Medical Sciences, Yokohama, Kanagawa, Japan
| | - Yosuke Isobe
- Laboratory for Metabolomics, RIKEN Center for Integrative Medical Sciences, Yokohama, Kanagawa, Japan; Division of Physiological Chemistry and Metabolism, Graduate School of Pharmaceutical Sciences, Keio University, Tokyo, Japan; Cellular and Molecular Epigenetics Laboratory, Graduate School of Medical Life Science, Yokohama City University, Yokohama, Kanagawa, Japan
| | - Yasushi Ishihama
- Department of Molecular Systems Bioanalysis, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan; Laboratory of Clinical and Analytical Chemistry, National Institute of Biomedical Innovation, Health and Nutrition, Osaka, Ibaraki, Japan
| | - Jun Seita
- Laboratory for Integrative Genomics, RIKEN Center for Integrative Medical Sciences, Yokohama, Kanagawa, Japan
| | - Makoto Arita
- Laboratory for Metabolomics, RIKEN Center for Integrative Medical Sciences, Yokohama, Kanagawa, Japan; Division of Physiological Chemistry and Metabolism, Graduate School of Pharmaceutical Sciences, Keio University, Tokyo, Japan; Cellular and Molecular Epigenetics Laboratory, Graduate School of Medical Life Science, Yokohama City University, Yokohama, Kanagawa, Japan; Human Biology-Microbiome-Quantum Research Center (WPI-Bio2Q), Keio University, Tokyo, Japan.
| | - Koshi Imami
- Proteome Homeostasis Research Unit, RIKEN Center for Integrative Medical Sciences, Yokohama, Kanagawa, Japan; Laboratory for Metabolomics, RIKEN Center for Integrative Medical Sciences, Yokohama, Kanagawa, Japan; Laboratory for Integrative Genomics, RIKEN Center for Integrative Medical Sciences, Yokohama, Kanagawa, Japan.
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Malmhäll-Bah E, Andersson KM, Erlandsson MC, Silfverswärd ST, Pullerits R, Bokarewa MI. Metabolic signature and proteasome activity controls synovial migration of CDC42hiCD14 + cells in rheumatoid arthritis. Front Immunol 2023; 14:1187093. [PMID: 37662900 PMCID: PMC10469903 DOI: 10.3389/fimmu.2023.1187093] [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: 03/15/2023] [Accepted: 07/31/2023] [Indexed: 09/05/2023] Open
Abstract
Objective Activation of Rho-GTPases in macrophages causes inflammation and severe arthritis in mice. In this study, we explore if Rho-GTPases define the joint destination of pathogenic leukocytes, the mechanism by which they perpetuate rheumatoid arthritis (RA), and how JAK inhibition mitigates these effects. Methods CD14+ cells of 136 RA patients were characterized by RNA sequencing and cytokine measurement to identify biological processes and transcriptional regulators specific for CDC42 hiCD14+ cells, which were summarized in a metabolic signature (MetSig). The effect of hypoxia and IFN-γ signaling on the metabolic signature of CD14+ cells was assessed experimentally. To investigate its connection with joint inflammation, the signature was translated into the single-cell characteristics of CDC42 hi synovial tissue macrophages. The sensitivity of MetSig to the RA disease activity and the treatment effect were assessed experimentally and clinically. Results CDC42 hiCD14+ cells carried MetSig of genes functional in the oxidative phosphorylation and proteasome-dependent cell remodeling, which correlated with the cytokine-rich migratory phenotype and antigen-presenting capacity of these cells. Integration of CDC42 hiCD14+ and synovial macrophages marked with MetSig revealed the important role of the interferon-rich environment and immunoproteasome expression in the homeostasis of these pathogenic macrophages. The CDC42 hiCD14+ cells were targeted by JAK inhibitors and responded with the downregulation of immunoproteasome and MHC-II molecules, which disintegrated the immunological synapse, reduced cytokine production, and alleviated arthritis. Conclusion This study shows that the CDC42-related MetSig identifies the antigen-presenting CD14+ cells that migrate to joints to coordinate autoimmunity. The accumulation of CDC42 hiCD14+ cells discloses patients perceptive to the JAKi treatment.
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Affiliation(s)
- Eric Malmhäll-Bah
- Department of Rheumatology and Inflammation Research, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Karin M.E. Andersson
- Department of Rheumatology and Inflammation Research, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Malin C. Erlandsson
- Department of Rheumatology and Inflammation Research, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden
- Rheumatology Clinic, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Sofia T. Silfverswärd
- Department of Rheumatology and Inflammation Research, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Rille Pullerits
- Rheumatology Clinic, Sahlgrenska University Hospital, Gothenburg, Sweden
- Department of Clinical Immunology and Transfusion Medicine, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Maria I. Bokarewa
- Department of Rheumatology and Inflammation Research, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden
- Rheumatology Clinic, Sahlgrenska University Hospital, Gothenburg, Sweden
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Stubbs EB. Isoprenylation of Monomeric GTPases in Human Trabecular Meshwork Cells. Methods Mol Biol 2023; 2625:217-230. [PMID: 36653646 DOI: 10.1007/978-1-0716-2966-6_19] [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] [Indexed: 01/19/2023]
Abstract
Small monomeric GTPases, including those belonging to the Rho family, regulate a diverse array of intracellular signaling pathways which affect vesicle transport/trafficking, endocytosis, cell cycle progression, cell contractility, and formation of stress fibers or focal adhesions. Functional activation of newly synthesized small monomeric GTPases is facilitated by a multi-step posttranslational process involving transferase-catalyzed addition of farnesyl or geranylgeranyl isoprenoids to conserved cysteine residues within a unique carboxy terminal -CaaX motif. Here, using well-established and widely available contemporary methodologies, detailed protocols by which to semi-quantitatively evaluate the functional consequence of posttranslational isoprenylation in human trabecular meshwork cells are described. We propose the novel concept that posttranslational isoprenylation itself is a key regulator of mammalian Rho GTPase protein expression and turnover.
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Affiliation(s)
- Evan B Stubbs
- Department of Veterans Affairs, Edward Hines Jr. VA Hospital, Hines, IL, USA.
- Department of Ophthalmology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL, USA.
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Wang Z, Zhang H, Li Y, Chen Y, Tang X, Zhao J, Yu F, Wang H, Xiao J, Liu J, Zhang X, Sun L, Xie Q, Wang X. Isoprenylation modification is required for HIPP1-mediated powdery mildew resistance in wheat. PLANT, CELL & ENVIRONMENT 2023; 46:288-305. [PMID: 36319595 DOI: 10.1111/pce.14479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2022] [Revised: 08/09/2022] [Accepted: 09/09/2022] [Indexed: 06/16/2023]
Abstract
Powdery mildew (Pm), caused by Blumeria graminis f.sp. tritici (Bgt), is one of the most important wheat diseases. Heavy-metal-associated isoprenylated plant protein (HIPP1) has been proved playing important roles in response to biotic and a biotic stress. In present study, we proved HIPP1-V from Haynalidia villosa is a positive regulator in Pm resistance. HIPP1-V was rapidly induced by Bgt. Transiently or stably heterologous overexpressing HIPP1-V in wheat suppressed the haustorium formation and enhanced Pm resistance. HIPP1-V isoprenylation was critical for plasma membrane (PM) localization, interaction with E3-ligase CMPG1-V and function in Pm resistance. Bgt infection recruited the isoprenylated HIPP1-V and CMPG1s on PM; blocking the HIPP1 isoprenylation reduced such recruitment and compromised the resistance of OE-CMPG1-V and OE-HIPP1-V. Overexpressing HIPP1-VC148G could not enhance Pm resistance. These indicated the Pm resistance was dependent on HIPP1-V's isoprenylation. DGEs related to the ROS and SA pathways were remarkably enriched in OE-HIPP1-V, revealing their involvement in Pm resistance. Our results provide evidence on the important role of protein isoprenylation in plant defense.
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Affiliation(s)
- Zongkuan Wang
- State Key Lab of Crop Genetics and Germplasm Enhancement, Cytogenetics Institute, College of Agriculture, Nanjing Agricultural University/JCIC-MCP, Nanjing, Jiangsu, China
| | - Heng Zhang
- State Key Lab of Crop Genetics and Germplasm Enhancement, Cytogenetics Institute, College of Agriculture, Nanjing Agricultural University/JCIC-MCP, Nanjing, Jiangsu, China
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences, Hangzhou, Zhejiang, China
| | - Yingbo Li
- State Key Lab of Crop Genetics and Germplasm Enhancement, Cytogenetics Institute, College of Agriculture, Nanjing Agricultural University/JCIC-MCP, Nanjing, Jiangsu, China
- Shanghai Key Laboratory of Agricultural Genetics and Breeding, Biotech Research Institute, Shanghai Academy of Agricultural Sciences, Shanghai, China
| | - Yiming Chen
- State Key Lab of Crop Genetics and Germplasm Enhancement, Cytogenetics Institute, College of Agriculture, Nanjing Agricultural University/JCIC-MCP, Nanjing, Jiangsu, China
| | - Xiong Tang
- State Key Lab of Crop Genetics and Germplasm Enhancement, Cytogenetics Institute, College of Agriculture, Nanjing Agricultural University/JCIC-MCP, Nanjing, Jiangsu, China
| | - Jia Zhao
- State Key Lab of Crop Genetics and Germplasm Enhancement, Cytogenetics Institute, College of Agriculture, Nanjing Agricultural University/JCIC-MCP, Nanjing, Jiangsu, China
| | - Feifei Yu
- Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Haiyan Wang
- State Key Lab of Crop Genetics and Germplasm Enhancement, Cytogenetics Institute, College of Agriculture, Nanjing Agricultural University/JCIC-MCP, Nanjing, Jiangsu, China
| | - Jin Xiao
- State Key Lab of Crop Genetics and Germplasm Enhancement, Cytogenetics Institute, College of Agriculture, Nanjing Agricultural University/JCIC-MCP, Nanjing, Jiangsu, China
| | - Jia Liu
- State Key Lab of Crop Genetics and Germplasm Enhancement, Cytogenetics Institute, College of Agriculture, Nanjing Agricultural University/JCIC-MCP, Nanjing, Jiangsu, China
| | - Xu Zhang
- State Key Lab of Crop Genetics and Germplasm Enhancement, Cytogenetics Institute, College of Agriculture, Nanjing Agricultural University/JCIC-MCP, Nanjing, Jiangsu, China
| | - Li Sun
- State Key Lab of Crop Genetics and Germplasm Enhancement, Cytogenetics Institute, College of Agriculture, Nanjing Agricultural University/JCIC-MCP, Nanjing, Jiangsu, China
| | - Qi Xie
- Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Xiue Wang
- State Key Lab of Crop Genetics and Germplasm Enhancement, Cytogenetics Institute, College of Agriculture, Nanjing Agricultural University/JCIC-MCP, Nanjing, Jiangsu, China
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Elsabrouty R, Jo Y, Hwang S, Jun DJ, DeBose-Boyd RA. Type 1 polyisoprenoid diphosphate phosphatase modulates geranylgeranyl-mediated control of HMG CoA reductase and UBIAD1. eLife 2021; 10:64688. [PMID: 34842525 PMCID: PMC8641950 DOI: 10.7554/elife.64688] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2020] [Accepted: 11/28/2021] [Indexed: 11/18/2022] Open
Abstract
UbiA prenyltransferase domain-containing protein-1 (UBIAD1) utilizes geranylgeranyl pyrophosphate (GGpp) to synthesize the vitamin K2 subtype menaquinone-4. The prenyltransferase has emerged as a key regulator of sterol-accelerated, endoplasmic reticulum (ER)-associated degradation (ERAD) of HMG CoA reductase, the rate-limiting enzyme in synthesis of cholesterol and nonsterol isoprenoids including GGpp. Sterols induce binding of UBIAD1 to reductase, inhibiting its ERAD. Geranylgeraniol (GGOH), the alcohol derivative of GGpp, disrupts this binding and thereby stimulates ERAD of reductase and translocation of UBIAD1 to Golgi. We now show that overexpression of Type 1 polyisoprenoid diphosphate phosphatase (PDP1), which dephosphorylates GGpp and other isoprenyl pyrophosphates to corresponding isoprenols, abolishes protein geranylgeranylation as well as GGOH-induced ERAD of reductase and Golgi transport of UBIAD1. Conversely, these reactions are enhanced in the absence of PDP1. Our findings indicate PDP1-mediated hydrolysis of GGpp significantly contributes to a feedback mechanism that maintains optimal intracellular levels of the nonsterol isoprenoid.
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Affiliation(s)
- Rania Elsabrouty
- Department of Molecular Genetics, University of Texas Southwestern Medical Center at Dallas, Dallas, United States
| | - Youngah Jo
- Department of Molecular Genetics, University of Texas Southwestern Medical Center at Dallas, Dallas, United States
| | - Seonghwan Hwang
- Department of Molecular Genetics, University of Texas Southwestern Medical Center at Dallas, Dallas, United States
| | - Dong-Jae Jun
- Department of Molecular Genetics, University of Texas Southwestern Medical Center at Dallas, Dallas, United States
| | - Russell A DeBose-Boyd
- Department of Molecular Genetics, University of Texas Southwestern Medical Center at Dallas, Dallas, United States
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Feng Z, Shi H, Lv M, Ma Y, Li J. Protein farnesylation negatively regulates brassinosteroid signaling via reducing BES1 stability in Arabidopsis thaliana. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2021; 63:1353-1366. [PMID: 33764637 PMCID: PMC8360029 DOI: 10.1111/jipb.13093] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Accepted: 03/23/2021] [Indexed: 06/12/2023]
Abstract
Brassinosteroids (BRs) are a group of steroidal phytohormones, playing critical roles in almost all physiological aspects during the life span of a plant. In Arabidopsis, BRs are perceived at the cell surface, triggering a reversible phosphorylation-based signaling cascade that leads to the activation and nuclear accumulation of a family of transcription factors, represented by BES1 and BZR1. Protein farnesylation is a type of post-translational modification, functioning in many important cellular processes. Previous studies demonstrated a role of farnesylation in BR biosynthesis via regulating the endoplasmic reticulum localization of a key bassinolide (BL) biosynthetic enzyme BR6ox2. Whether such a process is also involved in BR signaling is not understood. Here, we demonstrate that protein farnesylation is involved in mediating BR signaling in Arabidopsis. A loss-of-function mutant of ENHANCED RESPONSE TO ABA 1 (ERA1), encoding a β subunit of the protein farnesyl transferase holoenzyme, can alter the BL sensitivity of bak1-4 from a reduced to a hypersensitive level. era1 can partially rescue the BR defective phenotype of a heterozygous mutant of bin2-1, a gain-of-function mutant of BIN2 which encodes a negative regulator in the BR signaling. Our genetic and biochemical analyses revealed that ERA1 plays a significant role in regulating the protein stability of BES1.
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Affiliation(s)
- Zengxiu Feng
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Hongyong Shi
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Minghui Lv
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Yuang Ma
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Jia Li
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
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Rao VR, Stubbs EB. TGF-β2 Promotes Oxidative Stress in Human Trabecular Meshwork Cells by Selectively Enhancing NADPH Oxidase 4 Expression. Invest Ophthalmol Vis Sci 2021; 62:4. [PMID: 33821883 PMCID: PMC8039474 DOI: 10.1167/iovs.62.4.4] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 03/15/2021] [Indexed: 01/17/2023] Open
Abstract
Purpose The multifunctional profibrotic cytokine TGF-β2 is implicated in the pathophysiology of primary open angle glaucoma (POAG). While the underlying cause of POAG remains unclear, TGF-β2 dependent remodeling of the extracellular matrix (ECM) within the trabecular meshwork (TM) microenvironment is considered an early pathologic consequence associated with impaired aqueous humor (AH) outflow and elevated IOP. Mitochondrial-targeted antioxidants have been recently shown by our group to markedly attenuate TGF-β2 profibrotic responses, strongly implicating oxidative stress as a key facilitator of TGF-β2 signaling in human TM cells. In this study, we determined the mechanism by which oxidative stress facilitates TGF-β2 profibrotic responses in cultured primary human TM cells. Methods Semiconfluent cultures of primary or transformed human TM cells were conditioned overnight in serum-free media and subsequently challenged without or with TGF-β2 (5 ng/mL). Relative changes in the mRNA content of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (Nox) isoforms, connective tissue growth factor (CTGF), collagen 1α1 and 4α1 isoforms or relative changes in the protein content of Nox4, phospho- and total-Smad2 and -Smad3, collagens I and IV were determined in the absence or presence of GKT137831, a Nox1-Nox4 dual enzyme inhibitor, and quantified by real-time qPCR or by immunoblot, respectively. Relative in situ changes in collagens I and IV and in alpha smooth muscle actin (αSMA) were semiquantified by immunocytochemistry, whereas relative changes in filamentous actin stress fiber formation was semiquantified by phalloidin staining. Results Quiescent primary human TM cells cultured in the presence of TGF-β2 exhibited a marked selective increase in endogenous Nox4 mRNA and Nox4 protein expression. Actinomycin D prevented TGF-β2 mediated increases in Nox4 mRNA expression. TM cells reverse transfected with siRNA against Smad3 prevented TGF-β2 mediated increases in Nox4 mRNA expression. Pre-incubating TM cells with GKT137831 attenuated TGF-β2 mediated increases in intracellular reactive oxygen species (ROS), in COL1A1, COL4A1, and CTGF mRNA expression, in Smad3 protein phosphorylation, in collagens I, collagens IV, and αSMA protein expression, and in filamentous actin stress fiber formation. Conclusions TGF-β2 promotes oxidative stress in primary human TM cells by selectively increasing expression of NADPH oxidase 4. Dysregulation of redox equilibrium by induction of NADPH oxidase 4 expression appears to be a key early event involved in the pathologic profibrotic responses elicited by TGF-β2 canonical signaling, including ECM remodeling, filamentous actin stress fiber formation, and αSMA expression. Selective inhibition of Nox4 expression/activation, in combination with mitochondrial-targeted antioxidants, represents a novel strategy by which to slow the progression of TGF-β2 elicited profibrotic responses within the TM.
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Affiliation(s)
- Vidhya R. Rao
- Research Service, Department of Veterans Affairs, Edward Hines Jr. VA Hospital, Hines, IL, United States
- Department of Ophthalmology, Loyola University Health Science Division, Maywood, IL, United States
| | - Evan B. Stubbs
- Research Service, Department of Veterans Affairs, Edward Hines Jr. VA Hospital, Hines, IL, United States
- Department of Ophthalmology, Loyola University Health Science Division, Maywood, IL, United States
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Tabak S, Schreiber-Avissar S, Beit-Yannai E. Trabecular meshwork's collagen network formation is inhibited by non-pigmented ciliary epithelium-derived extracellular vesicles. J Cell Mol Med 2021; 25:3339-3347. [PMID: 33644975 PMCID: PMC8034463 DOI: 10.1111/jcmm.16408] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 02/07/2021] [Accepted: 02/09/2021] [Indexed: 12/22/2022] Open
Abstract
The present research aims to determine whether the application of non‐pigmented ciliary epithelium cells derived extracellular vesicles to human trabecular meshwork cells affects the formation and secretion of collagen type I to the extracellular matrix formation. Following the extraction of non‐pigmented ciliary epithelium derived extracellular vesicles by a precipitation method, their size and concentration were determined using tunable resistive pulse sensing technology. Extracellular vesicles were incubated with trabecular meshwork cells for 3 days. Morphological changes of collagen type I in the extracellular matrix of trabecular meshwork cells were visualized using confocal microscopy and scanning electron microscopy. A Sirius Red assay was used to determine the total amount of collagen. Finally, collagen type I expression levels in the extracellular matrix of trabecular meshwork cells were quantified by cell western analysis. We found that non‐pigmented ciliary epithelium extracellular vesicles were very effective at preventing collagen fibres formation by the trabecular meshwork cells, and their secretion to the extracellular matrix was significantly reduced (P < .001). Morphological changes in the extracellular matrix of trabecular meshwork cells were observed. Our study indicates that non‐pigmented ciliary epithelium extracellular vesicles can be used to control collagen type I fibrillogenesis in trabecular meshwork cells. These fibrils net‐like structure is responsible for remodelling the extracellular matrix. Moreover, we suggest that targeting collagen type I fibril assembly may be a viable treatment for primary open‐angle glaucoma abnormal matrix deposition of the extracellular matrix.
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Affiliation(s)
- Saray Tabak
- Clinical Biochemistry and Pharmacology Department, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Sofia Schreiber-Avissar
- Clinical Biochemistry and Pharmacology Department, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Elie Beit-Yannai
- Clinical Biochemistry and Pharmacology Department, Ben-Gurion University of the Negev, Beer-Sheva, Israel
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Stubbs EB. Targeting the blood-nerve barrier for the management of immune-mediated peripheral neuropathies. Exp Neurol 2020; 331:113385. [PMID: 32562668 DOI: 10.1016/j.expneurol.2020.113385] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 06/03/2020] [Accepted: 06/15/2020] [Indexed: 02/07/2023]
Abstract
Healthy peripheral nerves encounter, with increased frequency, numerous chemical, biological, and biomechanical forces. Over time and with increasing age, these forces collectively contribute to the pathophysiology of a spectrum of traumatic, metabolic, and/or immune-mediated peripheral nerve disorders. The blood-nerve barrier (BNB) serves as a critical first-line defense against chemical and biologic insults while biomechanical forces are continuously buffered by a dense array of longitudinally orientated epineural collagen fibers exhibiting high-tensile strength. As emphasized throughout this Experimental Neurology Special Issue, the BNB is best characterized as a functionally dynamic multicellular vascular unit comprised of not only highly specialized endoneurial endothelial cells, but also associated perineurial cells, pericytes, Schwann cells, basement membrane, and invested axons. The composition of the BNB, while anatomically distinct, is not functionally dissimilar to that of the well characterized neurovascular unit of the central nervous system. While the BNB lacks a glial limitans and an astrocytic endfoot layer, the primary function of both vascular units is to establish, maintain, and protect an optimal endoneurial (PNS) or interstitial (CNS) fluid microenvironment that is vital for proper neuronal function. Altered endoneurial homeostasis as a secondary consequence of BNB dysregulation is considered an early pathological event in the course of a variety of traumatic, immune-mediated, or metabolically acquired peripheral neuropathies. In this review, emerging experimental advancements targeting the endoneurial microvasculature for the therapeutic management of immune-mediated inflammatory peripheral neuropathies, including the AIDP variant of Guillain-Barré syndrome, are discussed.
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Affiliation(s)
- Evan B Stubbs
- Research Service (151), Department of Veterans Affairs, Edward Hines Jr. VA Hospital, Hines, IL 60141, USA; Department of Ophthalmology, Loyola University Health Science Division, Maywood, IL 60153, USA.
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Rao VR, Lautz JD, Kaja S, Foecking EM, Lukács E, Stubbs EB. Mitochondrial-Targeted Antioxidants Attenuate TGF-β2 Signaling in Human Trabecular Meshwork Cells. Invest Ophthalmol Vis Sci 2019; 60:3613-3624. [PMID: 31433458 DOI: 10.1167/iovs.19-27542] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose POAG is a progressive optic neuropathy that is currently the leading cause of irreversible blindness worldwide. While the underlying cause of POAG remains unclear, TGF-β2-dependent remodeling of the extracellular matrix (ECM) within the trabecular meshwork (TM) microenvironment is considered an early pathologic consequence associated with impaired aqueous humor (AH) outflow and elevated IOP. Early studies have also demonstrated markedly elevated levels of oxidative stress markers in AH from POAG patients along with altered expression of antioxidant defenses. Here, using cultured primary or transformed human TM cells, we investigated the role oxidative stress plays at regulating TGF-β2-mediated remodeling of the ECM. Methods Primary or transformed (GTM3) human TM cells conditioned in serum-free media were incubated in the absence or presence of TGF-β2 and relative changes in intracellular reactive oxygen species (ROS) were measured using oxidation-sensitive fluorogenic dyes CellROX green or 6-carboxy-2',7'-dichlorodihydrofluorescein diacetate (carboxy-H2DCFDA). TGF-β2-mediated changes in the content of connective tissue growth factor (CTGF) and collagen types 1α1 (COL1A1) and 4α1 (COL4A1) mRNA or collagens I and IV isoform proteins were determined in the absence or presence of mitochondrial-targeted antioxidants (XJB-5-131 or MitoQ) and quantified by quantitative PCR or by immunoblot and immunocytochemistry. Smad-dependent canonic signaling was determined by immunoblot, whereas Smad-dependent transcriptional activity was quantified using a Smad2/3-responsive SBE-luciferase reporter assay. Results Primary or transformed human TM cells cultured in the presence of TGF-β2 (5 ng/mL; 2 hours) exhibited marked increases in CellROX or fluorescein fluorescence. Consistent with previous reports, challenging cultured human TM cells with TGF-β2 elicited measurable increases in regulated Smad2/3 signaling as well as increases in CTGF, COL1A1, and COL4A1 mRNA and collagen protein content. Pretreating human TM cells with mitochondrial-targeted antioxidants XJB-5-131 (10 μM) or MitoQ (10 nM) attenuated TGF-β2-mediated changes in Smad-dependent transcriptional activity. Conclusions The multifunctional profibrotic cytokine TGF-β2 elicits a marked increase in oxidative stress in human TM cells. Mitochondrial-targeted antioxidants attenuate TGF-β2-mediated changes in Smad-dependent transcriptional activity, including marked reductions in CTGF and collagen isoform gene and protein expression. These findings suggest that mitochondrial-targeted antioxidants, when delivered directly to the TM, exhibit potential as a novel strategy by which to slow the progression of TGF-β2-mediated remodeling of the ECM within the TM.
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Affiliation(s)
- Vidhya R Rao
- Research Service, Department of Veterans Affairs, Edward Hines Jr. VA Hospital, Hines, Illinois, United States
- Department of Ophthalmology, Loyola University Health Science Division, Maywood, Illinois, United States
| | - Jonathan D Lautz
- Research Service, Department of Veterans Affairs, Edward Hines Jr. VA Hospital, Hines, Illinois, United States
- Program of Neuroscience, Loyola University Health Science Division, Maywood, Illinois, United States
| | - Simon Kaja
- Research Service, Department of Veterans Affairs, Edward Hines Jr. VA Hospital, Hines, Illinois, United States
- Department of Ophthalmology, Loyola University Health Science Division, Maywood, Illinois, United States
- Department of Molecular Pharmacology and Therapeutics, Loyola University Health Science Division, Maywood, Illinois, United States
| | - Eileen M Foecking
- Research Service, Department of Veterans Affairs, Edward Hines Jr. VA Hospital, Hines, Illinois, United States
- Department of Otolaryngology Head and Surgery, Loyola University Health Science Division, Maywood, Illinois, United States
| | - Emoke Lukács
- Research Service, Department of Veterans Affairs, Edward Hines Jr. VA Hospital, Hines, Illinois, United States
- Department of Ophthalmology, Loyola University Health Science Division, Maywood, Illinois, United States
| | - Evan B Stubbs
- Research Service, Department of Veterans Affairs, Edward Hines Jr. VA Hospital, Hines, Illinois, United States
- Department of Ophthalmology, Loyola University Health Science Division, Maywood, Illinois, United States
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Franco A, Soto T, Martín-García R, Madrid M, Vázquez-Marín B, Vicente-Soler J, Coll PM, Gacto M, Pérez P, Cansado J. Distinct functional relevance of dynamic GTPase cysteine methylation in fission yeast. Sci Rep 2017; 7:6057. [PMID: 28729673 PMCID: PMC5519673 DOI: 10.1038/s41598-017-06053-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Accepted: 06/07/2017] [Indexed: 12/11/2022] Open
Abstract
The final step in post-translational processing of Ras and Rho GTPases involves methylation of the prenylated cysteine residue by an isoprenylcysteine-O-carboxyl methyltransferase (ICMT). ICMT activity is essential for cell growth and development in higher eukaryotes, and inhibition of GTPase methylation has become an attractive target in cancer therapy to inactivate prenylated oncoproteins. However, the specificity and dynamics of the GTPase methylation process remain to be fully clarified. Notably, cells lacking Mam4, the ICMT ortholog in the fission yeast Schizosaccharomyces pombe, are viable. We have exploited this feature to analyze the role of methylation on GTPase localization and function. We show that methylation differentially affects GTPase membrane localization, being particularly relevant for plasma membrane tethering and downstream signaling of palmitoylated and farnesylated GTPases Ras1 and Rho2 lacking C-terminal polybasic motifs. Indeed, Ras1 and Rho2 cysteine methylation is required for proper regulation of differentiation elicited by MAPK Spk1 and for stress-dependent activation of the cell integrity pathway (CIP) and its main effector MAPK Pmk1. Further, Mam4 negatively regulates TORC2 signaling by a cross-inhibitory mechanism relying on Rho GTPase methylation. These results highlight the requirement for a tight control of GTPase methylation in vivo to allow adequate GTPase function.
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Affiliation(s)
- Alejandro Franco
- Yeast Physiology Group, Department of Genetics and Microbiology, Facultad de Biología, Universidad de Murcia, 30071, Murcia, Spain
| | - Teresa Soto
- Yeast Physiology Group, Department of Genetics and Microbiology, Facultad de Biología, Universidad de Murcia, 30071, Murcia, Spain
| | - Rebeca Martín-García
- Instituto de Biología Funcional y Genómica (IBFG), Consejo Superior de Investigaciones Científicas/Departamento de Microbiología y Genética, Universidad de Salamanca, 37007, Salamanca, Spain
| | - Marisa Madrid
- Yeast Physiology Group, Department of Genetics and Microbiology, Facultad de Biología, Universidad de Murcia, 30071, Murcia, Spain
| | - Beatriz Vázquez-Marín
- Yeast Physiology Group, Department of Genetics and Microbiology, Facultad de Biología, Universidad de Murcia, 30071, Murcia, Spain
| | - Jero Vicente-Soler
- Yeast Physiology Group, Department of Genetics and Microbiology, Facultad de Biología, Universidad de Murcia, 30071, Murcia, Spain
| | - Pedro M Coll
- Instituto de Biología Funcional y Genómica (IBFG), Consejo Superior de Investigaciones Científicas/Departamento de Microbiología y Genética, Universidad de Salamanca, 37007, Salamanca, Spain
| | - Mariano Gacto
- Yeast Physiology Group, Department of Genetics and Microbiology, Facultad de Biología, Universidad de Murcia, 30071, Murcia, Spain
| | - Pilar Pérez
- Instituto de Biología Funcional y Genómica (IBFG), Consejo Superior de Investigaciones Científicas/Departamento de Microbiología y Genética, Universidad de Salamanca, 37007, Salamanca, Spain
| | - José Cansado
- Yeast Physiology Group, Department of Genetics and Microbiology, Facultad de Biología, Universidad de Murcia, 30071, Murcia, Spain.
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Abstract
Small monomeric GTPases, including those belonging to the Rho family, regulate a diverse array of intracellular signaling pathways which affect vesicle transport/trafficking, endocytosis, cell cycle progression, cell contractility, and formation of stress fibers or focal adhesions. Functional activation of newly synthesized small monomeric GTPases is facilitated by a multistep post-translational process involving transferase-catalyzed addition of farnesyl or geranylgeranyl isoprenoids to conserved cysteine residues within a unique carboxy terminal CaaX motif. Here, using well-established and widely available contemporary methodologies, detailed protocols by which to semi-quantitatively evaluate the functional consequence of post-translational isoprenylation in human trabecular meshwork cells are described. We introduce the concept that isoprenylation alone is itself a key regulator of mammalian Rho GTPase expression and turnover.
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Affiliation(s)
- Evan B Stubbs
- Research Service, Department of Veterans Affairs, Edward Hines Jr. VA Hospital, Hines, IL, 60141, USA.
- Department of Ophthalmology, Stritch School of Medicine, Loyola University Chicago, 2160 South First Ave., LUH-North Entrance, Suite 2601, Maywood, IL, 60153, USA.
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Langert KA, Goshu B, Stubbs EB. Attenuation of experimental autoimmune neuritis with locally administered lovastatin-encapsulating poly(lactic-co-glycolic) acid nanoparticles. J Neurochem 2016; 140:334-346. [PMID: 27861905 DOI: 10.1111/jnc.13892] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Revised: 09/28/2016] [Accepted: 11/01/2016] [Indexed: 12/26/2022]
Abstract
Acute inflammatory demyelinating polyneuropathy (AIDP) is an aggressive antibody- and T-cell-mediated variant of Guillain-Barré Syndrome (GBS), a prominent and debilitating autoimmune disorder of the peripheral nervous system. Despite advancements in clinical management, treatment of patients with AIDP/GBS and its chronic variant CIDP remains palliative and relies on the use of non-specific immunemodulating therapies. Our laboratory has previously reported that therapeutic administration of statins safely attenuates the clinical severity of experimental autoimmune neuritis (EAN), a well-characterized animal model of AIDP/GBS, by restricting the migration of autoreactive leukocytes across peripheral nerve microvascular endoneurial endothelial cells that form the blood-nerve barrier. Despite these advancements, the clinical application of systemically administered statins for the management of inflammatory disorders remains controversial as a result of disappointingly inconclusive phase trials. Here, poly(lactic-co-glycolic) acid (PLGA) nanoparticles were evaluated as an alternative strategy by which to locally administer statins for the management of EAN. When tested in vitro, lovastatin-encapsulating PLGA nanoparticles elicited a marked increase in RhoB mRNA content in peripheral nerve microvascular endoneurial endothelial cells, similar to cells treated with activated unencapsulated lovastatin. Unilateral peri-neural administration of lovastatin-encapsulating PLGA nanoparticles, but not empty nanoparticles, to naïve Lewis rats similarly enhanced RhoB mRNA content in adjacent nerve and muscle tissue. When administered in this manner, serum levels of lovastatin were below the level of detection. Bilateral peri-neural administration of lovastatin-encapsulating PLGA nanoparticles to EAN-induced Lewis rats significantly attenuated EAN clinical severity while protecting against EAN-induced peripheral nerve morphological and functional deficits. This study provides the first proof-of-concept approach for the application of a nanoparticle-based local drug delivery platform for the management of inflammatory demyelinating diseases, including AIDP/GBS.
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Affiliation(s)
- Kelly A Langert
- Research Service, Department of Veterans Affairs, Edward Hines Jr. VA Hospital, Hines, Illinois, USA
| | - Bruktawit Goshu
- Research Service, Department of Veterans Affairs, Edward Hines Jr. VA Hospital, Hines, Illinois, USA
| | - Evan B Stubbs
- Research Service, Department of Veterans Affairs, Edward Hines Jr. VA Hospital, Hines, Illinois, USA.,Program of Neuroscience, Stritch School of Medicine, Loyola University Chicago, Maywood, Illinois, USA.,Department of Ophthalmology, Stritch School of Medicine, Loyola University Chicago, Maywood, Illinois, USA
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Szasz T, Webb RC. Rho-Mancing to Sensitize Calcium Signaling for Contraction in the Vasculature: Role of Rho Kinase. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2016; 78:303-322. [PMID: 28212799 DOI: 10.1016/bs.apha.2016.09.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Vascular smooth muscle contraction is an important physiological process contributing to cardiovascular homeostasis. The principal determinant of smooth muscle contraction is the intracellular free Ca2+ concentration, and phosphorylation of myosin light chain (MLC) by activated myosin light chain kinase (MLCK) in response to increased Ca2+ is the main pathway by which vasoconstrictor stimuli induce crossbridge cycling of myosin and actin filaments. A secondary pathway for vascular smooth muscle contraction that is not directly dependent on Ca2+ concentration, but rather mediating Ca2+ sensitization, is the RhoA/Rho kinase pathway. In response to contractile stimuli, the small GTPase RhoA activates its downstream effector Rho kinase which, in turn, promotes contraction via myosin light chain phosphatase (MLCP) inhibition. RhoA/Rho kinase-mediated MLCP inhibition occurs mainly by phosphorylation and inhibition of MYPT1, the regulatory subunit of MLCP, or by CPI-17-mediated inhibition of the catalytic subunit of MLCP. In this review, we describe the molecular mechanisms underlying the pivotal role exerted by Rho kinase on vascular smooth muscle contraction and discuss the main regulatory pathways for its activity.
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Affiliation(s)
- T Szasz
- Augusta University, Augusta, GA, United States.
| | - R C Webb
- Augusta University, Augusta, GA, United States
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18
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Elsayed M, Kobayashi D, Kubota T, Matsunaga N, Murata R, Yoshizawa Y, Watanabe N, Matsuura T, Tsurudome Y, Ogino T, Ohdo S, Shimazoe T. Synergistic Antiproliferative Effects of Zoledronic Acid and Fluvastatin on Human Pancreatic Cancer Cell Lines: An in Vitro Study. Biol Pharm Bull 2016; 39:1238-46. [PMID: 27181081 DOI: 10.1248/bpb.b15-00746] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Bisphosphonates and statins are known to have antitumor activities against different types of cancer cell lines. In the present study, we investigated the antiproliferative effects of the combination of zoledronic acid (ZOL), a bisphophosphonate, and fluvastatin (FLU), a statin, in vitro on two types of human pancreatic cancer cell lines, Mia PaCa-2 and Suit-2. The pancreatic cancer cell lines were treated with ZOL and FLU both individually and in combination to evaluate their antiproliferative effects using WST-8 cell proliferation assay. In this study, we demonstrated a potent synergistic antiproliferative effect of both drugs when used in combination in both cell lines. Moreover, we studied the molecular mechanism behind this synergistic effect, which was inhibited by the addition of the mevalonate pathway products, farnesyl pyrophosphate (FPP) and geranylgeranyl pyrophosphate (GGPP). Furthermore, we aimed to determine the effect of ZOL and FLU combination on RhoA and Ras guanosine 5'-triphosphate (GTP)-proteins. The combination induced a marked accumulation in RhoA and unprenylated Ras. GGPP and FPP reversed the increase in the amount of both proteins. These results indicated that the combination treatment impaired RhoA and Ras signaling pathway by the inhibition of geranylgeranylation and/or farnesylation. This study provides a potentially effective approach for the treatment of pancreatic cancer using a combination treatment of ZOL and FLU.
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Affiliation(s)
- Mahitab Elsayed
- Department of Clinical Pharmacy and Pharmaceutical Care, Graduate School of Pharmaceutical Sciences, Kyushu University
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Pervan CL, Lautz JD, Blitzer AL, Langert KA, Stubbs EB. Rho GTPase signaling promotes constitutive expression and release of TGF-β2 by human trabecular meshwork cells. Exp Eye Res 2016; 146:95-102. [PMID: 26743044 PMCID: PMC4893883 DOI: 10.1016/j.exer.2015.12.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Revised: 12/15/2015] [Accepted: 12/22/2015] [Indexed: 12/22/2022]
Abstract
Elevated intraocular pressure (IOP) is causally implicated in the pathophysiology of primary open-angle glaucoma (POAG). The molecular mechanisms responsible for elevated IOP remain elusive, but may involve aberrant expression and signaling of transforming growth factor (TGF)-β2 within the trabecular meshwork (TM). Consistent with previously published studies, we show here that exogenous addition of TGF-β2 to cultured porcine anterior segments significantly attenuates outflow facility in a time-dependent manner. By comparison, perfusing segments with a TGFβRI/ALK-5 antagonist (SB-431542) unexpectedly elicited a significant and sustained increase in outflow facility, implicating a role for TM-localized constitutive expression and release of TGF-β2. Consistent with this thesis, cultured primary or transformed (GTM3) quiescent human TM cells were found to constitutively express and secrete measurable amounts of biologically-active TGF-β2. Disrupting monomeric GTPase post-translational prenylation and activation with lovastatin or GGTI-298 markedly reduced constitutive TGF-β2 expression and release. Specifically, inhibiting the Rho subfamily of GTPases with C3 exoenzyme similarly reduced constitutive expression and secretion of TGF-β2. These findings suggest that Rho GTPase signaling, in part, regulates constitutive expression and release of biologically-active TGF-β2 from human TM cells. Localized constitutive expression and release of TGF-β2 by TM cells may promote or exacerbate elevation of IOP in POAG.
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Affiliation(s)
- Cynthia L Pervan
- Research Service, Department of Veterans Affairs, Edward Hines Jr. VA Hospital, Hines, IL, USA; Department of Ophthalmology, Loyola University Chicago, Maywood, IL, USA.
| | - Jonathan D Lautz
- Research Service, Department of Veterans Affairs, Edward Hines Jr. VA Hospital, Hines, IL, USA; Program in Neuroscience, Loyola University Chicago, Maywood, IL, USA
| | - Andrea L Blitzer
- Research Service, Department of Veterans Affairs, Edward Hines Jr. VA Hospital, Hines, IL, USA; Stritch School of Medicine, Loyola University Chicago, Maywood, IL, USA
| | - Kelly A Langert
- Research Service, Department of Veterans Affairs, Edward Hines Jr. VA Hospital, Hines, IL, USA
| | - Evan B Stubbs
- Research Service, Department of Veterans Affairs, Edward Hines Jr. VA Hospital, Hines, IL, USA; Department of Ophthalmology, Loyola University Chicago, Maywood, IL, USA; Program in Neuroscience, Loyola University Chicago, Maywood, IL, USA
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Langert KA, Von Zee CL, Stubbs EB. Cdc42 GTPases facilitate TNF-α-mediated secretion of CCL2 from peripheral nerve microvascular endoneurial endothelial cells. J Peripher Nerv Syst 2014; 18:199-208. [PMID: 24028188 DOI: 10.1111/jns5.12032] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2013] [Revised: 05/01/2013] [Accepted: 07/22/2013] [Indexed: 12/31/2022]
Abstract
Trafficking of autoreactive leukocytes across the blood-nerve barrier and into peripheral nerves is an early pathological hallmark of Guillain-Barré syndrome (GBS). Tumor necrosis factor-α (TNF-α), a proinflammatory cytokine, promotes transendothelial migration by upregulating endothelial expression of inflammatory mediators, including CCL2, a chemokine implicated in GBS. We sought to determine the mechanism by which TNF-α induces expression and secretion of CCL2 from peripheral nerve microvascular endoneurial endothelial cells (PNMECs). Expression of CCL2 mRNA and protein in quiescent PNMEC cultures was minimal. In contrast, cultures treated with TNF-α exhibited increased CCL2 mRNA and protein content, as well as protein secretion. Simvastatin significantly attenuated TNF-α-induced CCL2 secretion without affecting CCL2 mRNA or protein expression. Co-incubation with geranylgeranyl pyrophosphate, but not farnesyl pyrophosphate, prevented the effect of simvastatin. By comparison, inhibiting protein isoprenylation with GGTI-298, but not FTI-277, mimicked the effect of simvastatin and significantly attenuated transendothelial migration in vitro. Inhibition of the monomeric GTPase Cdc42, but not Rac1 or RhoA-C, attenuated TNF-α-mediated CCL2 secretion. TNF-α-mediated trafficking of autoreactive leukocytes into peripheral nerves during GBS may proceed by a mechanism that involves Cdc42-facilitated secretion of CCL2.
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Affiliation(s)
- Kelly A Langert
- Research Service, Department of Veterans Affairs, Edward Hines, Jr. VA Hospital, Hines, IL, USA; Program of Neuroscience
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Villarreal G, Chatterjee A, Oh SS, Oh DJ, Rhee DJ. Pharmacological regulation of SPARC by lovastatin in human trabecular meshwork cells. Invest Ophthalmol Vis Sci 2014; 55:1657-65. [PMID: 24474275 DOI: 10.1167/iovs.13-12712] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
PURPOSE Statins have been shown to increase aqueous outflow facility. The matricellular protein SPARC (secreted protein acidic and rich in cysteine) is a critical mediator of aqueous outflow and intraocular pressure (IOP). Here, we examine the effects of lovastatin on SPARC expression in trabecular meshwork (TM) cells, exploring the molecular mechanisms involved. METHODS Primary cultured human TM cells were incubated for 24, 48, and 72 hours with 10 μM lovastatin. In separate cultures, media was supplemented with either farnesyl pyrophosphate (FPP) or geranylgeranyl pyrophosphate (GGPP) for the duration of the 72-hour time point experiment. Trabecular meshwork cells were also pretreated for 24 hours with lovastatin followed by 24-hour stimulation with 3 ng/mL TGF-β2. Cell lysates and media were harvested and relative mRNA and protein level changes were determined. Krüppel-like factor 4 (KLF4) localization in normal human anterior segments was examined by immunofluorescence. Adenovirus expressing human KLF4 was used and relative changes in SPARC mRNA and protein levels were assessed. RESULTS Incubating TM cells with lovastatin suppressed SPARC mRNA and protein levels. This effect was reversed upon media supplementation with GGPP but not FPP. Pretreating cells with lovastatin inhibited TGF-β2 induction of SPARC. The KLF4 transcription factor was expressed throughout the TM and the inner and outer walls of Schlemm's canal. Lovastatin treatment upregulated KLF4 mRNA and protein levels. Overexpression of KLF4 downregulated SPARC expression. CONCLUSIONS Collectively, our data identify lovastatin as an important pharmacological suppressor of SPARC expression in TM cells, and provide further insight into the molecular mechanisms mediating statin enhancement of aqueous outflow facility.
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Affiliation(s)
- Guadalupe Villarreal
- Department of Ophthalmology, Massachusetts Eye & Ear Infirmary, Harvard Medical School, Boston, Massachusetts
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Pharmacological modulation of farnesyltransferase subtype I attenuates mecamylamine-precipitated nicotine withdrawal syndrome in mice. Behav Pharmacol 2013; 24:668-77. [DOI: 10.1097/fbp.0000000000000009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Rehni AK, Singh TG. Pharmacological modulation of geranylgeranyltransferase and farnesyltransferase attenuates opioid withdrawal in vivo and in vitro. Neuropharmacology 2013; 71:19-26. [PMID: 23415632 DOI: 10.1016/j.neuropharm.2013.01.022] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2012] [Revised: 01/15/2013] [Accepted: 01/20/2013] [Indexed: 11/29/2022]
Abstract
Geranylgeranyltransferase and farnesyltransferase I, are noted to mediate a number of signal transduction cascades which are known to be involved in the causation of opioid withdrawal syndrome. GGTI-2133 and FTI-276 are selective modulators of geranylgeranyltransferase and farnesyltransferase subtype 1 respectively. Therefore, the present study investigated the effect of GGTI-2133 and FTI-276 on propagation of morphine dependence and resultant withdrawal signs in vivo, in sub-chronic morphine mouse model, and in vitro, in isolated rat ileum. Morphine was administered twice daily for 5 days following which a single day 6 injection of naloxone (8 mg/kg, i.p.) precipitated opioid withdrawal syndrome in mice. Withdrawal syndrome was quantitatively assessed in terms of withdrawal severity score and the frequency of jumping, rearing, fore paw licking & circling. Naloxone induced contraction in morphine withdrawn isolated rat ileum was employed as an in vitro model of opioid withdrawal syndrome. An isobolographic study design was employed to assess a potential synergistic activity between GGTI-2133 and FTI-276. GGTI-2133 and FTI-276 dose dependently attenuated naloxone induced morphine withdrawal syndrome both in vivo and in vitro. GGTI-2133 was also observed to exert a synergistic interaction with FTI-276. It is concluded that GGTI-2133 and FTI-276 attenuate the propagation of morphine dependence and reduce withdrawal signs possibly by a geranylgeranyl transferase; farnesyltransferase activation pathway linked mechanisms potentially in an interdependent manner.
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Affiliation(s)
- Ashish K Rehni
- Department of Pharmacology, Chitkara College of Pharmacy, Chitkara University, Chandigarh Patiala National Highway, Rajpura, Patiala 147002 Punjab, India.
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