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Danziger M, Xu F, Noble H, Yang P, Roque DM. Tubulin Complexity in Cancer and Metastasis. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2024; 1452:21-35. [PMID: 38805123 DOI: 10.1007/978-3-031-58311-7_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
Tubulin plays a fundamental role in cellular function and as the subject for microtubule-active agents in the treatment of ovarian cancer. Microtubule-binding proteins (e.g., tau, MAP1/2/4, EB1, CLIP, TOG, survivin, stathmin) and posttranslational modifications (e.g., tyrosination, deglutamylation, acetylation, glycation, phosphorylation, polyamination) further diversify tubulin functionality and may permit additional opportunities to understand microtubule behavior in disease and to develop microtubule-modifying approaches to combat ovarian cancer. Tubulin-based structures that project from suspended ovarian cancer cells known as microtentacles may contribute to metastatic potential of ovarian cancer cells and could represent an exciting novel therapeutic target.
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Affiliation(s)
- Michael Danziger
- Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Fuhua Xu
- Division of Gynecologic Oncology, Greenebaum Comprehensive Cancer Center, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Helen Noble
- Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Peixin Yang
- Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Dana M Roque
- Division of Gynecologic Oncology, Greenebaum Comprehensive Cancer Center, University of Maryland School of Medicine, Baltimore, MD, USA.
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2
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Moore KBE, Hung TJ, Fortin JS. Hyperphosphorylated tau (p-tau) and drug discovery in the context of Alzheimer's disease and related tauopathies. Drug Discov Today 2023; 28:103487. [PMID: 36634842 PMCID: PMC9975055 DOI: 10.1016/j.drudis.2023.103487] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 12/14/2022] [Accepted: 01/03/2023] [Indexed: 01/11/2023]
Abstract
Alzheimer's disease (AD) is the most common form of dementia, characterized by intracellular neurofibrillary tangles (NFTs) and extracellular β-amyloid (βA) plaques. No disease-modifying therapy is currently available to prevent the progression of, or cure, the disease. Misfolded hyperphosphorylated tau (p-tau) is considered a pivotal point in the pathogenesis of AD and other tauopathies. Compelling evidence suggests that it is a key driver of the accumulation of NFTs and can be directly correlated with the extent of dementia in patients with AD. Therefore, inhibiting tau hyperphosphorylation-induced aggregation could be a viable strategy to discover and develop therapeutics for patients with AD.
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Affiliation(s)
- Kendall B E Moore
- Department of Basic Medical Sciences, College of Veterinary Medicine, Purdue University, 625 Harrison Street, West Lafayette, IN, USA
| | - Ta-Jung Hung
- Department of Basic Medical Sciences, College of Veterinary Medicine, Purdue University, 625 Harrison Street, West Lafayette, IN, USA
| | - Jessica S Fortin
- Department of Basic Medical Sciences, College of Veterinary Medicine, Purdue University, 625 Harrison Street, West Lafayette, IN, USA.
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3
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Guan G, Cannon RD, Coates DE, Mei L. Effect of the Rho-Kinase/ROCK Signaling Pathway on Cytoskeleton Components. Genes (Basel) 2023; 14:272. [PMID: 36833199 PMCID: PMC9957420 DOI: 10.3390/genes14020272] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 01/10/2023] [Accepted: 01/16/2023] [Indexed: 01/22/2023] Open
Abstract
The mechanical properties of cells are important in tissue homeostasis and enable cell growth, division, migration and the epithelial-mesenchymal transition. Mechanical properties are determined to a large extent by the cytoskeleton. The cytoskeleton is a complex and dynamic network composed of microfilaments, intermediate filaments and microtubules. These cellular structures confer both cell shape and mechanical properties. The architecture of the networks formed by the cytoskeleton is regulated by several pathways, a key one being the Rho-kinase/ROCK signaling pathway. This review describes the role of ROCK (Rho-associated coiled-coil forming kinase) and how it mediates effects on the key components of the cytoskeleton that are critical for cell behaviour.
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Affiliation(s)
- Guangzhao Guan
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin 9016, New Zealand
- Department of Oral Diagnostic and Surgical Sciences, Faculty of Dentistry, University of Otago, 310 Great King Street, Dunedin 9016, New Zealand
| | - Richard D. Cannon
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin 9016, New Zealand
- Department of Oral Sciences, Faculty of Dentistry, University of Otago, 310 Great King Street, Dunedin 9016, New Zealand
| | - Dawn E. Coates
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin 9016, New Zealand
| | - Li Mei
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin 9016, New Zealand
- Department of Oral Sciences, Faculty of Dentistry, University of Otago, 310 Great King Street, Dunedin 9016, New Zealand
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4
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Ciliate Microtubule Diversities: Insights from the EFBTU3 Tubulin in the Antarctic Ciliate Euplotes focardii. Microorganisms 2022; 10:microorganisms10122415. [PMID: 36557668 PMCID: PMC9784925 DOI: 10.3390/microorganisms10122415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 12/01/2022] [Accepted: 12/02/2022] [Indexed: 12/12/2022] Open
Abstract
Protozoans of the Phylum Ciliophora (ciliates) assemble many diverse microtubular structures in a single cell throughout the life cycle, a feature that made them useful models to study microtubule complexity and the role of tubulin isotypes. In the Antarctic ciliate Euplotes focardii we identified five β-tubulin isotypes by genome sequencing, named EFBTU1, EFBTU2, EFBTU3, EFBTU4 and EFBTU5. By using polyclonal antibodies directed against EFBTU2/EFBTU1 and EFBTU3, we show that the former isotypes appear to be involved in the formation of all microtubular structures and are particularly abundant in cilia, whereas the latter specifically localizes at the bases of cilia. By RNA interference (RNAi) technology, we silenced the EFBTU3 gene and provided evidence that this isotype has a relevant role in cilia regeneration upon deciliation and in cell division. These results support the long-standing concept that tubulin isotypes possess functional specificity in building diverse microtubular structures.
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Reconstitution of microtubule into GTP-responsive nanocapsules. Nat Commun 2022; 13:5424. [PMID: 36109556 PMCID: PMC9477877 DOI: 10.1038/s41467-022-33156-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2022] [Accepted: 09/05/2022] [Indexed: 11/29/2022] Open
Abstract
Nanocapsules that collapse in response to guanosine triphosphate (GTP) have the potential as drug carriers for efficiently curing diseases caused by cancer and RNA viruses because GTP is present at high levels in such diseased cells and tissues. However, known GTP-responsive carriers also respond to adenosine triphosphate (ATP), which is abundant in normal cells as well. Here, we report the elaborate reconstitution of microtubule into a nanocapsule that selectively responds to GTP. When the tubulin monomer from microtubule is incubated at 37 °C with a mixture of GTP (17 mol%) and nonhydrolysable GTP* (83 mol%), a tubulin nanosheet forms. Upon addition of photoreactive molecular glue to the resulting dispersion, the nanosheet is transformed into a nanocapsule. Cell death results when a doxorubicin-containing nanocapsule, after photochemically crosslinked for properly stabilizing its shell, is taken up into cancer cells that overexpress GTP. GTP-triggered release from drug carriers has huge potential in cancer therapy but current carriers suffers from off target release due to ATP also acting as a trigger. Here, the authors report on the development of a microtubule capsule which is engineered to be responsive to only GTP not ATP and demonstrate targeted drug delivery.
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6
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Guo R, Fujito R, Nagasaki A, Okumura M, Chihara T, Hamao K. Dynamin-2 regulates microtubule stability via an endocytosis-independent mechanism. Cytoskeleton (Hoboken) 2022; 79:94-104. [PMID: 36053962 DOI: 10.1002/cm.21723] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 06/03/2022] [Accepted: 07/07/2022] [Indexed: 01/30/2023]
Abstract
Microtubule stability and dynamics regulations are essential for vital cellular processes, such as microtubule-dependent axonal transport. Dynamin is involved in many membrane fission events, such as clathrin-mediated endocytosis. The ubiquitously expressed dynamin-2 has been reported to regulate microtubule stability. However, the underlying molecular mechanisms remain unclear. This study aimed to investigate the roles of intrinsic properties of dynamin-2 on microtubule regulation by rescue experiments. A heterozygous DNM2 mutation in HeLa cells was generated, and an increase in the level of stabilized microtubules in these heterozygous cells was observed. The expression of wild-type dynamin-2 in heterozygous cells reduced stabilized microtubules. Conversely, the expression of self-assembly-defective mutants of dynamin-2 in the heterozygous cells failed to decrease stabilized microtubules. This indicated that the self-assembling ability of dynamin-2 is necessary for regulating microtubule stability. Moreover, the heterozygous cells expressing the GTPase-defective dynamin-2 mutant, K44A, reduced microtubule stabilization, similar to the cells expressing wild-type dynamin-2, suggesting that GTPase activity of dynamin-2 is not essential for regulating microtubule stability. These results showed that the mechanism of microtubule regulation by dynamin-2 is diverse from that of endocytosis.
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Affiliation(s)
- Runzhao Guo
- Program of Biomedical Science, Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan
| | - Ryuji Fujito
- Program of Basic Biology, Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan
| | - Akira Nagasaki
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Ibaraki, Japan
| | - Misako Okumura
- Program of Biomedical Science, Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan.,Program of Basic Biology, Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan
| | - Takahiro Chihara
- Program of Biomedical Science, Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan.,Program of Basic Biology, Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan
| | - Kozue Hamao
- Program of Biomedical Science, Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan.,Program of Basic Biology, Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan
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7
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Chimplee S, Smythe C, Tipmanee V, Sukrong S, Kanokwiroon K. Anticancer mechanism of 7-α-hydroxyfrullanolide on microtubules and computational prediction of its target binding in triple-negative breast cancer cells. PeerJ 2022; 10:e13508. [PMID: 35651747 PMCID: PMC9150694 DOI: 10.7717/peerj.13508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Accepted: 05/06/2022] [Indexed: 01/17/2023] Open
Abstract
Background Triple-negative breast cancer (TNBC) responds poorly to the available drugs; thus, the mortality rate associated with TNBC remains high. 7-α-Hydroxyfrullanolide (7HF) possesses anticancer properties and arrests cells in the G2/M-phase via modulation of several proteins involved in the G2/M-phase transition, as well as the mitotic checkpoint in MDA-MB-468 (TNBC) cells. Microtubules (MTs) dynamically regulate cell division in the G2/M phase and are related to cancer cell stress response. However, antimitotic drug cytotoxicity to multiple cancer resistance developed in response to drugs are obstacles faced to date. Here, the activity and mechanism via which 7HF controls MTs dynamics was investigated in MDA-MB-468 cells. Methods 7HF uptake by MDA-MB-468 cells was assessed using spectrophotometry. The drug-like properties of 7HF were predicted using the Swiss-absorption, distribution, metabolism, and excretion (ADME) webtool. Then, the effect of 7HF treatment (6, 12, and 24 µM) on the dynamic arrangement of MTs was assessed for 1, 12, and 24 h using indirect immunofluorescence. Polymerization of α- and β-tubulin was assessed using different 7HF concentrations in a cell-free system for 1 h. Cell proliferation assay with bromodeoxyuridine plus propidium iodide staining and flow cytometry was performed at different 7HF concentrations and time points. The mechanism of action was assessed by detecting the expression of proteins, including Bub3, cyclin B1, p-Cdk1 (Tyr15), Rb, p-Rb (Ser780), Chk1, p-Chk1 (Ser345), Chk2, p-Chk2 (Ser516), and p-H2AX (Ser139), using western blotting. Molecular docking was used to predict the molecular interactions between 7HF and tubulins in MTs. Results We observed that 7HF was able to enter the MDA-MB-468 cells. The ADME webtool analysis predicted that it possesses the high passive permeation and gastrointestinal absorption properties of drugs. Various concentrations of 7HF disrupted the dynamic arrangement of spindle MTs by causing radial spindle array shrinkage and expansion of fibrous spindle density and radial array lengths in a time-dependent manner. 7HF reduced polymerization of α-, β-tubulin in dose-dependent manner. 7HF also triggered DNA damage response by inducing G2/M and G1 phase arrests in a concentration and time-dependent manner, which occurred due to the upregulation of Bub3, Chk1, p-Chk1 (Ser345), p-Cdk1 (Tyr15), and cyclin B1. According to molecular docking analysis, 7HF preferred to bind to β-tubulin over α-tubulin. The lactone, ketone, and hydroxyl groups of 7HF supported the 7HF-tubulin interactions. Hydrogen bonding with a hydrocarbon ring and salt bridge attractive forces were responsible for the binding versatility of 7HF. Conclusions This is the first study to investigate the molecular mechanism, MTs interacting sites, and the internalization and drug-like properties of 7HF in TNBC cells. The findings will be useful for developing 7HF-based treatment for patients with TNBC.
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Affiliation(s)
- Siriphorn Chimplee
- Department of Biomedical Sciences and Biomedical Engineering, Faculty of Medicine, Prince of Songkla University, Hat Yai, Songkhla, Thailand
| | - Carl Smythe
- School of Biosciences, University of Sheffield, Sheffield, United Kingdom
| | - Varomyalin Tipmanee
- Department of Biomedical Sciences and Biomedical Engineering, Faculty of Medicine, Prince of Songkla University, Hat Yai, Songkhla, Thailand
| | - Suchada Sukrong
- Center of Excellence in DNA Barcoding of Thai Medicinal Plants, Department of Pharmacognosy and Pharmaceutical Botany, Faculty of Pharmaceutical Sciences, Chulalongkorn University, Bangkok, Thailand
| | - Kanyanatt Kanokwiroon
- Department of Biomedical Sciences and Biomedical Engineering, Faculty of Medicine, Prince of Songkla University, Hat Yai, Songkhla, Thailand
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8
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Boichuk S, Syuzov K, Bikinieva F, Galembikova A, Zykova S, Gankova K, Igidov S, Igidov N. Computational-Based Discovery of the Anti-Cancer Activities of Pyrrole-Based Compounds Targeting the Colchicine-Binding Site of Tubulin. Molecules 2022; 27:2873. [PMID: 35566235 PMCID: PMC9101527 DOI: 10.3390/molecules27092873] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2022] [Revised: 04/27/2022] [Accepted: 04/29/2022] [Indexed: 12/10/2022] Open
Abstract
Despite the tubulin-binding agents (TBAs) that are widely used in the clinic for cancer therapy, tumor resistance to TBAs (both inherited and acquired) significantly impairs their effectiveness, thereby decreasing overall survival (OS) and progression-free survival (PFS) rates, especially for the patients with metastatic, recurrent, and unresectable forms of the disease. Therefore, the development of novel effective drugs interfering with the microtubules' dynamic state remains a big challenge in current oncology. We report here about the novel ethyl 2-amino-1-(furan-2-carboxamido)-5-(2-aryl/tert-butyl-2-oxoethylidene)-4-oxo-4,5-dihydro-1H-pyrrole-3-carboxylates (EAPCs) exhibiting potent anti-cancer activities against the breast and lung cancer cell lines in vitro. This was due to their ability to inhibit tubulin polymerization and induce cell cycle arrest in M-phase. As an outcome, the EAPC-treated cancer cells exhibited a significant increase in apoptosis, which was evidenced by the expression of cleaved forms of PARP, caspase-3, and increased numbers of Annexin-V-positive cells. By using the in silico molecular modeling methods (e.g., induced-fit docking, binding metadynamics, and unbiased molecular dynamics), we found that EAPC-67 and -70 preferentially bind to the colchicine-binding site of tubulin. Lastly, we have shown that the EAPCs indicated above and colchicine utilizes a similar molecular mechanism to inhibit tubulin polymerization via targeting the T7 loop in the β-chain of tubulin, thereby preventing the conformational changes in the tubulin dimers required for their polymerization. Collectively, we identified the novel and potent TBAs that bind to the colchicine-binding site and disrupt the microtubule network. As a result of these events, the compounds induced a robust cell cycle arrest in M-phase and exhibited potent pro-apoptotic activities against the epithelial cancer cell lines in vitro.
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Affiliation(s)
- Sergei Boichuk
- Department of Pathology, Kazan State Medical University, 420012 Kazan, Russia; (K.S.); (F.B.); (A.G.)
- Department of Radiotherapy and Radiology, Russian Medical Academy of Continuous Professional Education, 125993 Moscow, Russia
- Biologically Active Terpenoids Laboratory, Kazan Federal University, 18 Kremlyovskaya St., 420008 Kazan, Russia
| | - Kirill Syuzov
- Department of Pathology, Kazan State Medical University, 420012 Kazan, Russia; (K.S.); (F.B.); (A.G.)
| | - Firuza Bikinieva
- Department of Pathology, Kazan State Medical University, 420012 Kazan, Russia; (K.S.); (F.B.); (A.G.)
| | - Aigul Galembikova
- Department of Pathology, Kazan State Medical University, 420012 Kazan, Russia; (K.S.); (F.B.); (A.G.)
| | - Svetlana Zykova
- Department of Pharmacology, Perm State Academy of Pharmacy, 614990 Perm, Russia; (S.Z.); (K.G.); (S.I.); (N.I.)
| | - Ksenia Gankova
- Department of Pharmacology, Perm State Academy of Pharmacy, 614990 Perm, Russia; (S.Z.); (K.G.); (S.I.); (N.I.)
| | - Sergei Igidov
- Department of Pharmacology, Perm State Academy of Pharmacy, 614990 Perm, Russia; (S.Z.); (K.G.); (S.I.); (N.I.)
| | - Nazim Igidov
- Department of Pharmacology, Perm State Academy of Pharmacy, 614990 Perm, Russia; (S.Z.); (K.G.); (S.I.); (N.I.)
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Computational-Based Discovery of the Anti-Cancer Activities of Pyrrole-Based Compounds Targeting the Colchicine-Binding Site of Tubulin. Molecules 2022. [PMID: 35566235 DOI: 10.3390/molecules27092873.(] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023] Open
Abstract
Despite the tubulin-binding agents (TBAs) that are widely used in the clinic for cancer therapy, tumor resistance to TBAs (both inherited and acquired) significantly impairs their effectiveness, thereby decreasing overall survival (OS) and progression-free survival (PFS) rates, especially for the patients with metastatic, recurrent, and unresectable forms of the disease. Therefore, the development of novel effective drugs interfering with the microtubules' dynamic state remains a big challenge in current oncology. We report here about the novel ethyl 2-amino-1-(furan-2-carboxamido)-5-(2-aryl/tert-butyl-2-oxoethylidene)-4-oxo-4,5-dihydro-1H-pyrrole-3-carboxylates (EAPCs) exhibiting potent anti-cancer activities against the breast and lung cancer cell lines in vitro. This was due to their ability to inhibit tubulin polymerization and induce cell cycle arrest in M-phase. As an outcome, the EAPC-treated cancer cells exhibited a significant increase in apoptosis, which was evidenced by the expression of cleaved forms of PARP, caspase-3, and increased numbers of Annexin-V-positive cells. By using the in silico molecular modeling methods (e.g., induced-fit docking, binding metadynamics, and unbiased molecular dynamics), we found that EAPC-67 and -70 preferentially bind to the colchicine-binding site of tubulin. Lastly, we have shown that the EAPCs indicated above and colchicine utilizes a similar molecular mechanism to inhibit tubulin polymerization via targeting the T7 loop in the β-chain of tubulin, thereby preventing the conformational changes in the tubulin dimers required for their polymerization. Collectively, we identified the novel and potent TBAs that bind to the colchicine-binding site and disrupt the microtubule network. As a result of these events, the compounds induced a robust cell cycle arrest in M-phase and exhibited potent pro-apoptotic activities against the epithelial cancer cell lines in vitro.
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10
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Alteration of Neural Stem Cell Functions in Ataxia and Male Sterility Mice: A Possible Role of β-Tubulin Glutamylation in Neurodegeneration. Cells 2021; 10:cells10010155. [PMID: 33466875 PMCID: PMC7830091 DOI: 10.3390/cells10010155] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 01/09/2021] [Accepted: 01/11/2021] [Indexed: 12/20/2022] Open
Abstract
Ataxia and Male Sterility (AMS) is a mutant mouse strain that contains a missense mutation in the coding region of Nna1, a gene that encodes a deglutamylase. AMS mice exhibit early cerebellar Purkinje cell degeneration and an ataxic phenotype in an autosomal recessive manner. To understand the underlying mechanism, we generated neuronal stem cell (NSC) lines from wild-type (NMW7), Nna1 mutation heterozygous (NME), and Nna1 mutation homozygous (NMO1) mouse brains. The NNA1 levels were decreased, and the glutamylated tubulin levels were increased in NMO1 cultures as well as in the cerebellum of AMS mice at both 15 and 30 days of age. However, total β-tubulin protein levels were not altered in the AMS cerebellum. In NMO1 neurosphere cultures, β-tubulin protein levels were increased without changes at the transcriptional level. NMO1 grew faster than other NSC lines, and some of the neurospheres were attached to the plate after 3 days. Immunostaining revealed that SOX2 and nestin levels were decreased in NMO1 neurospheres and that the neuronal differentiation potentials were reduced in NMO1 cells compared to NME or NMW7 cells. These results demonstrate that the AMS mutation decreased the NNA1 levels and increased glutamylation in the cerebellum of AMS mice. The observed changes in glutamylation might alter NSC properties and the neuron maturation process, leading to Purkinje cell death in AMS mice.
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Kwon S, Kim KS. Qualitative analysis of contribution of intracellular skeletal changes to cellular elasticity. Cell Mol Life Sci 2020; 77:1345-1355. [PMID: 31605149 PMCID: PMC11105102 DOI: 10.1007/s00018-019-03328-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Revised: 09/25/2019] [Accepted: 09/30/2019] [Indexed: 01/07/2023]
Abstract
Cells are dynamic structures that continually generate and sustain mechanical forces within their environments. Cells respond to mechanical forces by changing their shape, moving, and differentiating. These reactions are caused by intracellular skeletal changes, which induce changes in cellular mechanical properties such as stiffness, elasticity, viscoelasticity, and adhesiveness. Interdisciplinary research combining molecular biology with physics and mechanical engineering has been conducted to characterize cellular mechanical properties and understand the fundamental mechanisms of mechanotransduction. In this review, we focus on the role of cytoskeletal proteins in cellular mechanics. The specific role of each cytoskeletal protein, including actin, intermediate filaments, and microtubules, on cellular elasticity is summarized along with the effects of interactions between the fibers.
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Affiliation(s)
- Sangwoo Kwon
- Department of Biomedical Engineering, College of Medicine, Kyung Hee University, 1 Hoegi-dong, Dongdaemun-gu, Seoul, 02447, Republic of Korea
| | - Kyung Sook Kim
- Department of Biomedical Engineering, College of Medicine, Kyung Hee University, 1 Hoegi-dong, Dongdaemun-gu, Seoul, 02447, Republic of Korea.
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12
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Herbs-partitioned moxibustion improves intestinal epithelial tight junctions by upregulating A20 expression in a mouse model of Crohn’s disease. Biomed Pharmacother 2019; 118:109149. [DOI: 10.1016/j.biopha.2019.109149] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 06/09/2019] [Accepted: 06/17/2019] [Indexed: 02/06/2023] Open
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13
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Theart RP, Loos B, Powrie YSL, Niesler TR. Improved region of interest selection and colocalization analysis in three-dimensional fluorescence microscopy samples using virtual reality. PLoS One 2018; 13:e0201965. [PMID: 30157239 PMCID: PMC6114514 DOI: 10.1371/journal.pone.0201965] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Accepted: 07/25/2018] [Indexed: 11/21/2022] Open
Abstract
Although modern fluorescence microscopy produces detailed three-dimensional (3D) datasets, colocalization analysis and region of interest (ROI) selection is most commonly performed two-dimensionally (2D) using maximum intensity projections (MIP). However, these 2D projections exclude much of the available data. Furthermore, 2D ROI selections cannot adequately select complex 3D structures which may inadvertently lead to either the exclusion of relevant or the inclusion of irrelevant data points, consequently affecting the accuracy of the colocalization analysis. Using a virtual reality (VR) enabled system, we demonstrate that 3D visualization, sample interrogation and analysis can be achieved in a highly controlled and precise manner. We calculate several key colocalization metrics using both 2D and 3D derived super-resolved structured illumination-based data sets. Using a neuronal injury model, we investigate the change in colocalization between Tau and acetylated α-tubulin at control conditions, after 6 hours and again after 24 hours. We demonstrate that performing colocalization analysis in 3D enhances its sensitivity, leading to a greater number of statistically significant differences than could be established when using 2D methods. Moreover, by carefully delimiting the 3D structures under analysis using the 3D VR system, we were able to reveal a time dependent loss in colocalization between the Tau and microtubule network as an early event in neuronal injury. This behavior could not be reliably detected using a 2D based projection. We conclude that, using 3D colocalization analysis, biologically relevant samples can be interrogated and assessed with greater precision, thereby better exploiting the potential of fluorescence-based image analysis in biomedical research.
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Affiliation(s)
- Rensu P. Theart
- Department of Electrical and Electronic Engineering, Stellenbosch University, Stellenbosch, Western Cape, South Africa
| | - Ben Loos
- Department of Physiological Sciences, Stellenbosch University, Stellenbosch, Western Cape, South Africa
| | - Yigael S. L. Powrie
- Department of Physiological Sciences, Stellenbosch University, Stellenbosch, Western Cape, South Africa
| | - Thomas R. Niesler
- Department of Electrical and Electronic Engineering, Stellenbosch University, Stellenbosch, Western Cape, South Africa
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14
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Abstract
Microtubules, constituted by end-to-end negatively charged α- and β-tubulin dimers, are long, hollow, pseudohelical cylinders with internal and external diameters of about 16 and 26 nm, respectively, and widely exist in cell cytoplasm, neuron axons, and dendrites. Although their structural functions in physiological processes, such as cell mitosis, cell motility, and motor protein transport, have been widely accepted, their role in neuron activity remains attractively elusive. Here we show a new function of microtubules: they can generate instant response to a calcium pulse because of their specific permeability for ions. Our comprehensive simulations from all-atom molecular dynamics to potential of mean force and continuum modeling reveal that K+ and Na+ ions can permeate through the nanopores in the microtubule wall easily, while Ca2+ ions are blocked by the wall with a much higher free energy barrier. These cations are adsorbed to the surfaces of the wall with affinity decreasing in the sequence Ca2+, Na+, and K+. As a result, when the concentration of Ca2+ ions increases outside the microtubule during neuronal excitation, K+ and Na+ ions will be driven into the microtubule, triggering subsequent axial ion redistribution within the microtubule. The results shed light on the possibility of the ion-permeable microtubules being involved in neural signal processing.
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Affiliation(s)
- Chun Shen
- State Key Laboratory of Mechanics and Control of Mechanical Structure and Key Laboratory for Intelligent Nano Materials and Devices of the Ministry of Education, and Institute of Nanoscience , Nanjing University of Aeronautics and Astronautics , Nanjing 210016 , China
| | - Wanlin Guo
- State Key Laboratory of Mechanics and Control of Mechanical Structure and Key Laboratory for Intelligent Nano Materials and Devices of the Ministry of Education, and Institute of Nanoscience , Nanjing University of Aeronautics and Astronautics , Nanjing 210016 , China
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15
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Stock V, Sutter A, Raschke M, Queisser N. A tripartite mode of action approach for investigating the impact of aneugens on tubulin polymerization. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2018; 59:188-201. [PMID: 29205516 DOI: 10.1002/em.22158] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Revised: 10/06/2017] [Accepted: 10/23/2017] [Indexed: 06/07/2023]
Abstract
Chemical-induced disruption of the cellular microtubule network is one key mechanism of aneugenicity. Since recent data indicate that genotoxic effects of aneugens show nonlinear dose-response relationships, margins of safety can be derived with the ultimate goal to perform a risk assessment for the support of drug development. Furthermore, microtubule-interacting compounds are widely used for cancer treatment. While there is a need to support the risk assessment of tubulin-interacting chemicals using reliable mechanistic assays, no standard assays exist to date in regulatory genotoxicity testing for the distinction of aneugenic mechanisms. Recently reported methods exclusively rely on either biochemical, morphological, or cytometric endpoints. Since data requirements for the diverse fields of application of those assays differ strongly, the use of multiple assays for a correct classification of aneugens is ideal. We here report a tripartite mode of action approach comprising a cell-free biochemical polymerization assay and the cell-based methods cellular imaging and flow cytometry. The biochemical assay measures tubulin polymerization over time whereas the two cell-based assays quantify tubulin polymer mass. We herein show that the flow cytometric method yielded IC50 values for tubulin destabilizers and EC50 values for tubulin stabilizers as well as cell cycle information. In contrast, cellular imaging complemented these findings with characteristic morphological patterns. Biochemical analysis yielded kinetic information on tubulin polymerization. This multiplex approach is able to create holistic effect profiles which can be individually customized to the research question with regard to quality, quantity, usability, and economy. Environ. Mol. Mutagen. 59:188-201, 2018. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Valerie Stock
- Bayer AG, Investigational Toxicology, Muellerstraße 178, Berlin, 13353, Germany
| | - Andreas Sutter
- Bayer AG, Investigational Toxicology, Muellerstraße 178, Berlin, 13353, Germany
| | - Marian Raschke
- Bayer AG, Investigational Toxicology, Muellerstraße 178, Berlin, 13353, Germany
| | - Nina Queisser
- Bayer AG, Investigational Toxicology, Muellerstraße 178, Berlin, 13353, Germany
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16
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Gilmore SP, Gonye ALK, Li EC, Espinosa de Los Reyes S, Gupton JT, Quintero OA, Fischer-Stenger K. Effects of a novel microtubule-depolymerizer on pro-inflammatory signaling in RAW264.7 macrophages. Chem Biol Interact 2018; 280:109-116. [PMID: 29247640 PMCID: PMC5766364 DOI: 10.1016/j.cbi.2017.12.019] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Revised: 12/04/2017] [Accepted: 12/12/2017] [Indexed: 12/21/2022]
Abstract
The Nuclear Factor-kappa B (NF-κB) pathway is vital for immune system regulation and pro-inflammatory signaling. Many inflammatory disorders and diseases, including cancer, are linked to dysregulation of NF-κB signaling. When macrophages recognize the presence of a pathogen, the signaling pathway is activated, resulting in the nuclear translocation of the transcription factor, NF-κB, to turn on pro-inflammatory genes. Here, we demonstrate the effects of a novel microtubule depolymerizer, NT-07-16, a polysubstituted pyrrole compound, on this process. Treatment with NT-07-16 decreased the production of pro-inflammatory cytokines in RAW264.7 mouse macrophages. It appears that the reduction in pro-inflammatory mediators produced by the macrophages after exposure to NT-07-16 may be due to activities upstream of the translocation of NF-κB into the nucleus. NF-κB translocation occurs after its inhibitory protein, IκB-α is phosphorylated which signals for its degradation releasing NF-κB so it is free to move into the nucleus. Previous studies from other laboratories indicate that these processes are associated with the microtubule network. Our results show that exposure to the microtubule-depolymerizer, NT-07-16 reduces the phosphorylation of IκB-α and also decreases the association of NF-κB with tubulin which may affect the ability of NF-κB to translocate into the nucleus. Therefore, the anti-inflammatory activity of NT-07-16 may be explained, at least in part, by alterations in these steps in the NF-κB signaling pathway leading to less NF-κB entering the nucleus and reducing the production of pro-inflammatory mediators by the activated macrophages.
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Affiliation(s)
| | - Anna L K Gonye
- Department of Biology, University of Richmond, VA 23173, USA.
| | - Elizabeth C Li
- Department of Biology, University of Richmond, VA 23173, USA.
| | | | - John T Gupton
- Department of Chemistry, University of Richmond, VA 23173, USA.
| | - Omar A Quintero
- Department of Biology, University of Richmond, VA 23173, USA.
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17
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Wu BJ, Zhao LX, Zhu CC, Chen YL, Wei MY, Bao SQ, Sun SC, Li XH. Altered apoptosis/autophagy and epigenetic modifications cause the impaired postimplantation octaploid embryonic development in mice. Cell Cycle 2016; 16:82-90. [PMID: 27830977 DOI: 10.1080/15384101.2016.1252884] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Polyploids are pervasive in plants and have large impacts on crop breeding, but natural polyploids are rare in animals. Mouse diploid embryos can be induced to become tetraploid by blastomere fusion at the 2-cell stage and tetraploid embryos can develop to the blastocyst stage in vitro. However, there is little information regarding mouse octaploid embryonic development and precise mechanisms contributing to octaploid embryonic developmental limitations are unknown. To investigate the genetic and epigenetic mechanisms underlying octaploid embryonic development, we generated mouse octaploid embryos and evaluated the in vitro/in vivo developmental potential. Here we show that octaploid embryos can develop to the blastocyst stage in vitro, but all fetus impaired immediately after implantation. Our results indicate that cell lineage specification of octaploid embryo was disorganized. Furthermore, these octaploid embryos showed increased apoptosis as well as alterations in epigenetic modifications when compared with diploid embryos. Thus, our cumulative data provide cues for why mouse octaploid embryonic development is limited and its failed postimplantation development.
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Affiliation(s)
- Bao-Jiang Wu
- a College of Animal Science and Technology, Nanjing Agricultural University , Nanjing , China.,b Research Center for Animal Genetic Resources of Mongolia Plateau, College of Life Science, Inner Mongolia University , Huhhot , China.,c Inner Mongolia Saikexing Institute of Breeding and Reproductive Biotechnology in Domestic Animal , Huhhot , China
| | - Li-Xia Zhao
- b Research Center for Animal Genetic Resources of Mongolia Plateau, College of Life Science, Inner Mongolia University , Huhhot , China.,c Inner Mongolia Saikexing Institute of Breeding and Reproductive Biotechnology in Domestic Animal , Huhhot , China
| | - Cheng-Cheng Zhu
- a College of Animal Science and Technology, Nanjing Agricultural University , Nanjing , China
| | - Yang-Lin Chen
- b Research Center for Animal Genetic Resources of Mongolia Plateau, College of Life Science, Inner Mongolia University , Huhhot , China
| | - Meng-Yi Wei
- b Research Center for Animal Genetic Resources of Mongolia Plateau, College of Life Science, Inner Mongolia University , Huhhot , China
| | - Si-Qin Bao
- b Research Center for Animal Genetic Resources of Mongolia Plateau, College of Life Science, Inner Mongolia University , Huhhot , China.,c Inner Mongolia Saikexing Institute of Breeding and Reproductive Biotechnology in Domestic Animal , Huhhot , China
| | - Shao-Chen Sun
- a College of Animal Science and Technology, Nanjing Agricultural University , Nanjing , China
| | - Xi-He Li
- b Research Center for Animal Genetic Resources of Mongolia Plateau, College of Life Science, Inner Mongolia University , Huhhot , China.,c Inner Mongolia Saikexing Institute of Breeding and Reproductive Biotechnology in Domestic Animal , Huhhot , China
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18
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Maintenance of electrostatic stabilization in altered tubulin lateral contacts may facilitate formation of helical filaments in foraminifera. Sci Rep 2016; 6:31723. [PMID: 27539392 PMCID: PMC4990898 DOI: 10.1038/srep31723] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Accepted: 07/14/2016] [Indexed: 11/13/2022] Open
Abstract
Microtubules in foraminiferan protists (forams) can convert into helical filament structures, in which longitudinal intraprotofilament interactions between tubulin heterodimers are thought to be lost, while lateral contacts across protofilaments are still maintained. The coarse geometric features of helical filaments are known through low-resolution negative stain electron microscopy (EM). In this study, geometric restraints derived from these experimental data were used to generate an average atomic-scale helical filament model, which anticipated a modest reorientation in the lateral tubulin heterodimer interface. Restrained molecular dynamics (MD) simulations of the nearest neighbor interactions combined with a Genalized Born implicit solvent model were used to assess the lateral, longitudinal, and seam contacts in 13-3 microtubules and the reoriented lateral contacts in the helical filament model. This electrostatic analysis suggests that the change in the lateral interface in the helical filament does not greatly diminish the lateral electrostatic interaction. After longitudinal dissociation, the 13-3 seam interaction is much weaker than the reoriented lateral interface in the helical filament model, providing a plausible atomic-detail explanation for seam-to-lateral contact transition that enables the transition to a helical filament structure.
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Direct Fusion between Poly(ethylene oxide)-lipid Modified Liposomes and Murine Mitotic B16 Melanoma Cells. J BIOACT COMPAT POL 2016. [DOI: 10.1177/0883911506069869] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The interactions between the poly(ethylene oxide)-bearing lipid (PEO-lipid) were investigated with the average number of ethylene oxide units of 5, 15 and 32-reconstituted egg PC liposomes and murine mitotic B16 melanoma cells. Water-soluble FITC-dextran (20kDa) and lipophilic octadecyl rhodamine B (OD-RhoB) were encapsulated in liposomes to study the interaction modes with these cells by fluorescence microscopic techniques. Both fluorescent probes loaded in the PEO-lipid (n 32, 20mol%)-reconstituted liposome were specifically transferred to the mitotic cells. This process was not inhibited at 4°C or after the treatment of endocytosis inhibitor cytochalasin B or D. Confocal fluorescence microscopic observation of the cells treated with the liposome at 4°C revealed that FITC-dextran and OD-RhoB were transferred to the cytosol and the plasma membrane, respectively. In addition, when the mitotic cells were treated with the PEO-lipid (n 32, 20mol%)-reconstituted liposome encapsulated diphtheria toxin fragment A (DTA), approximately 30% of the cells were killed by the DTA-dependent cytotoxicity. These data indicate that the PEO-lipid (n 32, 20mol%)-reconstituted liposome directly fused with the plasma membrane of the murine mitotic B16 melanoma cells.
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Penazzi L, Bakota L, Brandt R. Microtubule Dynamics in Neuronal Development, Plasticity, and Neurodegeneration. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2015; 321:89-169. [PMID: 26811287 DOI: 10.1016/bs.ircmb.2015.09.004] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Neurons are the basic information-processing units of the nervous system. In fulfilling their task, they establish a structural polarity with an axon that can be over a meter long and dendrites with a complex arbor, which can harbor ten-thousands of spines. Microtubules and their associated proteins play important roles during the development of neuronal morphology, the plasticity of neurons, and neurodegenerative processes. They are dynamic structures, which can quickly adapt to changes in the environment and establish a structural scaffold with high local variations in composition and stability. This review presents a comprehensive overview about the role of microtubules and their dynamic behavior during the formation and maturation of processes and spines in the healthy brain, during aging and under neurodegenerative conditions. The review ends with a discussion of microtubule-targeted therapies as a perspective for the supportive treatment of neurodegenerative disorders.
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Affiliation(s)
- Lorène Penazzi
- Department of Neurobiology, University of Osnabrück, Osnabrück, Germany
| | - Lidia Bakota
- Department of Neurobiology, University of Osnabrück, Osnabrück, Germany
| | - Roland Brandt
- Department of Neurobiology, University of Osnabrück, Osnabrück, Germany
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Lu Y, Liu C, Xu YF, Cheng H, Shi S, Wu CT, Yu XJ. Stathmin destabilizing microtubule dynamics promotes malignant potential in cancer cells by epithelial-mesenchymal transition. Hepatobiliary Pancreat Dis Int 2014; 13:386-94. [PMID: 25100123 DOI: 10.1016/s1499-3872(14)60038-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND Stathmin is a ubiquitous cytosolic regulatory phosphoprotein and is overexpressed in different human malignancies. The main physiological function of stathmin is to interfere with microtubule dynamics by promoting depolymerization of microtubules or by preventing polymerization of tubulin heterodimers. Stathmin plays important roles in regulating many cellular functions as a result of its microtubule-destabilizing activity. Currently, the critical roles of stathmin in cancer cells, as well as in lymphocytes have been valued. This review discusses stathmin and microtubule dynamics in cancer development, and hypothesizes their possible relationship with epithelial-mesenchymal transition (EMT). DATA SOURCES A PubMed search using such terms as "stathmin", "microtubule dynamics", "epithelial-mesenchymal transition", "EMT", "malignant potential" and "cancer" was performed to identify relevant studies published in English. More than 100 related articles were reviewed. RESULTS The literature clearly documented the relationship between stathmin and its microtubule-destabilizing activity of cancer development. However, the particular mechanism is poorly understood. Microtubule disruption is essential for EMT, which is a crucial process during cancer development. As a microtubule-destabilizing protein, stathmin may promote malignant potential in cancer cells by initiating EMT. CONCLUSIONS We propose that there is a stathmin-microtubule dynamics-EMT (S-M-E) axis during cancer development. By this axis, stathmin together with its microtubule-destabilizing activity contributes to EMT, which stimulates the malignant potential in cancer cells.
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Affiliation(s)
- Yu Lu
- Pancreatic Cancer Institute, Fudan University; Department of Pancreatic and Hepatobiliary Surgery, Fudan University Shanghai Cancer Center; Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, China.
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Nomura T, Watanabe S, Kaneko K, Yamanaka K, Nukina N, Furukawa Y. Intranuclear aggregation of mutant FUS/TLS as a molecular pathomechanism of amyotrophic lateral sclerosis. J Biol Chem 2013; 289:1192-202. [PMID: 24280224 DOI: 10.1074/jbc.m113.516492] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Dominant mutations in FUS/TLS cause a familial form of amyotrophic lateral sclerosis (fALS), where abnormal accumulation of mutant FUS proteins in cytoplasm has been observed as a major pathological change. Many of pathogenic mutations have been shown to deteriorate the nuclear localization signal in FUS and thereby facilitate cytoplasmic mislocalization of mutant proteins. Several other mutations, however, exhibit no effects on the nuclear localization of FUS in cultured cells, and their roles in the pathomechanism of fALS remain obscure. Here, we show that a pathogenic mutation, G156E, significantly increases the propensities for aggregation of FUS in vitro and in vivo. Spontaneous in vitro formation of amyloid-like fibrillar aggregates was observed in mutant but not wild-type FUS, and notably, those fibrils functioned as efficient seeds to trigger the aggregation of wild-type protein. In addition, the G156E mutation did not disturb the nuclear localization of FUS but facilitated the formation of intranuclear inclusions in rat hippocampal neurons with significant cytotoxicity. We thus propose that intranuclear aggregation of FUS triggered by a subset of pathogenic mutations is an alternative pathomechanism of FUS-related fALS diseases.
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Affiliation(s)
- Takao Nomura
- From the Department of Chemistry, Laboratory for Mechanistic Chemistry of Biomolecules, Keio University, Yokohama, Kanagawa 223-8522
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23
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Lopus M. Mechanism of mitotic arrest induced by dolastatin 15 involves loss of tension across kinetochore pairs. Mol Cell Biochem 2013; 382:93-102. [DOI: 10.1007/s11010-013-1721-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Accepted: 05/29/2013] [Indexed: 10/26/2022]
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24
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Machida S, Watanabe-Nakayama T, Saito M, Afrin R, Ikai A. Fabricated cantilever for AFM measurements and manipulations: Pre-stress analysis of stress fibers. Micron 2012; 43:1380-9. [DOI: 10.1016/j.micron.2012.03.025] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2011] [Revised: 03/30/2012] [Accepted: 03/30/2012] [Indexed: 11/28/2022]
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25
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Mondello S, Gabrielli A, Catani S, D'Ippolito M, Jeromin A, Ciaramella A, Bossù P, Schmid K, Tortella F, Wang KKW, Hayes RL, Formisano R. Increased levels of serum MAP-2 at 6-months correlate with improved outcome in survivors of severe traumatic brain injury. Brain Inj 2012; 26:1629-35. [PMID: 22794497 DOI: 10.3109/02699052.2012.700083] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVE To evaluate microtubule-associated proteins (MAP-2), a dendritic marker of both acute damage and chronic neuronal regeneration after injury, in serum of survivors after severe TBI and examine the association with long-term outcome. METHODS Serum concentrations of MAP-2 were evaluated in 16 patients with severe TBI (Glasgow Coma Scale score [GCS] ≤ 8) 6 months post-injury and in 16 controls. Physical and cognitive outcomes were assessed, using the Glasgow Outcome Scale Extended (GOSE) and Levels of Cognitive Functioning Scale (LCFS), respectively. RESULTS Severe TBI patients had significantly higher serum MAP-2 concentrations than normal controls with no history of TBI (p = 0.008) at 6 months post-injury. MAP-2 levels correlated with the GOSE (r = 0.58, p = 0.02) and LCFS (r = 0.65, p = 0.007) at month 6. Significantly lower serum levels of MAP-2 were observed in patients in a vegetative state (VS) compared to non-VS patients (p < 0.05). A trend tracking the level of consciousness was observed. CONCLUSIONS Severe TBI results in a chronic release of MAP-2 into the peripheral circulation in patients with higher levels of consciousness, suggesting that remodelling of synaptic junctions and neuroplasticity processes occur several months after injury. The data indicate MAP-2 as a potential marker for emergence to higher levels of cognitive function.
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Affiliation(s)
- Stefania Mondello
- University of Florida, Department of Anesthesiology, Gainesville, FL, USA.
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26
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Kamal A, Reddy MK, Shaik TB, Rajender, Srikanth YVV, Reddy VS, Kumar GB, Kalivendi SV. Synthesis of terphenyl benzimidazoles as tubulin polymerization inhibitors. Eur J Med Chem 2012; 50:9-17. [PMID: 22361684 DOI: 10.1016/j.ejmech.2012.01.004] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2011] [Revised: 01/03/2012] [Accepted: 01/05/2012] [Indexed: 10/14/2022]
Abstract
A series of new terphenyl benzimidazoles (3a-z and 3aa-ad) were synthesized and evaluated for their anticancer activity. All the 30 compounds have shown moderate to good anticancer potency, however some of the compounds (3j, 3m-t and 3aa-ad) exhibited prominent anticancer potency with GI(50) values ranging from <0.1 to 9.72 μM. These compounds exhibit G2/M phase arrest and the analysis of tubulin by Western blot experiments in case of 3t and 3ad shows the disturbances that are caused in the ratio of soluble versus polymerized tubulin in cells. Compounds 3t and 3ad are the most promising candidates amongst the series and has the potential to be taken up for further detailed studies either alone or in combination with the existing therapies.
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Affiliation(s)
- Ahmed Kamal
- Division of Organic Chemistry, Indian Institute of Chemical Technology, Hyderabad 500607, India.
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27
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Structure–activity relationship study of arylsulfonylimidazolidinones as anticancer agents. Bioorg Med Chem Lett 2011; 21:6829-32. [DOI: 10.1016/j.bmcl.2011.09.025] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2011] [Revised: 08/28/2011] [Accepted: 09/07/2011] [Indexed: 11/24/2022]
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28
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Structure–activity relationship studies of novel arylsulfonylimidazolidinones for their anticancer activity. Eur J Med Chem 2011; 46:3258-64. [DOI: 10.1016/j.ejmech.2011.04.042] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2010] [Revised: 04/11/2011] [Accepted: 04/14/2011] [Indexed: 11/24/2022]
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29
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Machida S, Watanabe-Nakayama T, Harada I, Afrin R, Nakayama T, Ikai A. Direct manipulation of intracellular stress fibres using a hook-shaped AFM probe. NANOTECHNOLOGY 2010; 21:385102. [PMID: 20798461 DOI: 10.1088/0957-4484/21/38/385102] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Atomic force microscopy (AFM) is a highly successful technique for imaging nanometre-sized samples and measuring pico- to nano-newton forces acting between atoms and molecules. When it comes to the manipulation of larger samples with forces of tens and hundreds of nano-newtons, however, the present chemistry-based modification protocols for functionalizing AFM cantilevers to achieve the formation of covalent/non-covalent linkages between the AFM probe and the sample surface do not produce strong enough bonds. For the purpose of measuring the fracture strength and other mechanical properties of stress fibres (SFs) in living as well as semi-intact fibroblast cells, we fabricated an AFM probe with a hooking function by focused ion beam technology and used the AFM probe hook to capture, pull and eventually sever a chosen SF labelled with green or red fluorescent protein.
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Affiliation(s)
- Shinichi Machida
- Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Midori-ku, Yokohama, Kanagawa, Japan.
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30
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Takano Y, Kubo Y, Kuroda I, Furusawa I. Temporal Transcriptional Pattern of Three Melanin Biosynthesis Genes, PKS1, SCD1, and THR1, in Appressorium-Differentiating and Nondifferentiating Conidia of Colletotrichum lagenarium. Appl Environ Microbiol 2010; 63:351-4. [PMID: 16535499 PMCID: PMC1389113 DOI: 10.1128/aem.63.1.351-354.1997] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A phytopathogenic fungus, Colletotrichum lagenarium, produces melanized appressoria that display temperature-sensitive differentiation. Conidia incubated in water at 24(deg)C germinated, and germ tubes differentiated into melanized appressoria. On the other hand, conidia incubated in water at 32(deg)C germinated and produced germ tubes that elongated without appressorium differentiation. Conidia in 0.1% yeast extract solution at 32(deg)C germinated and developed into vegetative hyphae. In this study, we investigated the temporal transcriptional pattern of cloned melanin biosynthesis genes, PKS1, SCD1, and THR1, in these differentiating and nondifferentiating conidia. During appressorium differentiation, de novo transcripts of the three melanin biosynthesis genes accumulated 1 to 2 h after the start of conidial incubation at 24(deg)C, and the amount of transcripts began to decrease at 6 h. In conidia germinating in water at 32(deg)C, the transcriptional pattern of the PKS1, SCD1, and THR1 genes was similar to that of these genes in appressorium-forming conidia, although no appressoria were formed. However, in conidia in 0.1% yeast extract solution at 32(deg)C, transcripts of the three melanin biosynthesis genes hardly accumulated.
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31
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He XY, Tang ZP, Zhang YL. Advance in enteric epithelial barrier and inflammatory bowel disease. Shijie Huaren Xiaohua Zazhi 2008; 16:3316-3320. [DOI: 10.11569/wcjd.v16.i29.3316] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Enteric epithelial barrier injury is a new field of the study on the cellular and molecular pathegenesis of inflammatory bowel disease (IBD) in recent years. The enteric epithelial barrier is one of the most important line of defense. Once the enteric epithelial barrier, one of the most important defense line in intestinal mucosa, is damaged, the permeability of enteric epithelium will increase, which is significantly involved in the genesis of IBD. At present, most researches mainly concentrate on the changes of intestinal epithelial cells and the structure and function of intercellular tight junction. Maintenance and repair of enteric epithelial barrier may be the ideal strategy for IBD therapy.
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Abstract
PURPOSE The epothilones are effective antitumor medications for patients with breast cancer, including patients who have been previously treated with or are resistant to anthracyclines or the taxanes. SUMMARY With the best currently available therapies, the median survival time for patients with metastatic breast cancer is only 2-3 years, and many patients develop resistance to taxanes or other chemotherapy drugs. The epothilones are a novel class of antitumor medications, similar to the taxanes in some respects, but that also possess several advantages. Like taxanes, epothilones are believed to produce antitumor effects by binding to and stabilizing intracellular microtubules, which are essential in DNA replication and cell division. Several in vitro and animal studies have shown that the epothilones are more potent microtubule stabilizers than the taxanes, they are effective against cancer cell lines with high levels of drug resistance, and they induce the regression of taxane-resistant human tumors. Preclinical studies also have demonstrated synergistic increases in tumor cell killing when the epothilones are combined with other antitumor medications. Epothilone B (patupilone) has been evaluated in a series of phase I and II clinical trials, which demonstrated disease stabilization or objective responses in patients with a variety of cancers, including ovarian, prostate, breast, colon, stomach, and kidney cancers. This agent is currently being evaluated in phase III clinical trials. A second epothilone, ixabepilone, was recently approved by the FDA for the treatment of metastatic breast cancer. Ixabepilone was evaluated as monotherapy for the treatment of breast cancer in phase II clinical trials of previously untreated patients and in taxane-experienced and taxane-resistant disease. A phase III clinical trial demonstrated that the combination of ixabepilone and capecitabine was superior to capecitabine alone in heavily pretreated, taxane-resistant patients. CONCLUSION Ongoing clinical trials will continue to define the role of the epothilones in cancer therapy.
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Affiliation(s)
- Susan Goodin
- The Cancer Institute of New Jersey, New Brunswick, New Jersey, USA.
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Fischer AJ, Ritchey ER, Scott MA, Wynne A. Bullwhip neurons in the retina regulate the size and shape of the eye. Dev Biol 2008; 317:196-212. [PMID: 18358467 DOI: 10.1016/j.ydbio.2008.02.023] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2007] [Revised: 02/04/2008] [Accepted: 02/08/2008] [Indexed: 02/07/2023]
Abstract
Bullwhip and mini-bullwhip cells are unconventional types of retinal neurons that utilize the neuropeptides glucagon, glucagon-like peptide 1 (GLP1) and substance P. These cells have been implicated in regulating the proliferation of neural progenitors in the circumferential marginal zone (CMZ) of the chicken retina. The purpose of this study was to investigate the roles of the bullwhip cells in regulating ocular size and shape. We found that intravitreal delivery of colchicine at postnatal day 7 destroys the vast majority (approximately 98%) of the bullwhip and mini-bullwhip cells and their peptidergic terminals that are concentrated in the CMZ near the equator of the eye. Interestingly, colchicine-treatment resulted in excessive ocular growth that involved the expansion of equatorial diameter, but not axial length. Intraocular injections of glucagon completely prevented the equatorial expansion that occurs with colchicine-treatment. In eyes with undamaged retinas, exogenous glucagon suppressed equatorial eye growth, whereas glucagon receptor antagonists caused excessive equatorial growth. Furthermore, visual stimuli that increase or decrease rates of ocular growth caused a down- or up-regulation, respectively, of the immediate early gene Egr1 in the bullwhip cells; indicating that the activity of the bullwhip cells is regulated by growth-guiding visual cues. We found that the glucagon receptor was expressed by cells in the fibrous and cartilaginous sclera in equatorial regions of the eye. Taken together, these findings suggest that glucagon peptide released from the terminals of the bullwhip and mini-bullwhip cells regulates the growth of the equatorial sclera in a vision-dependent manner. Although the bullwhip and mini-bullwhip cells are not abundant, less than 1000 cells per retina, their influence on the development of the eye is substantial and includes vision-guided ocular growth.
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Affiliation(s)
- Andy J Fischer
- Department of Neuroscience, College of Medicine, Columbus, OH 43210-1239, USA.
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Tabish M. Expression of gamma-tubulin during the development of nematode Caenorhabditis elegans. Mol Biol Rep 2006; 34:233-40. [PMID: 17160625 DOI: 10.1007/s11033-006-9038-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2006] [Accepted: 11/13/2006] [Indexed: 10/23/2022]
Abstract
Gamma-tubulin is a centrosomal protein found in microtubule organizing centres (MTOCs) in cells from many different organisms, and has several properties, which makes it a candidate for both the initiation of microtubule assembly and anchorage. Gamma-tubulin is encoded by a single gene tbg-1 in Caenorhabditis elegans. In this paper tbg-1 was studied to understand the essential role of gamma-tubulin in C. elegans. Essential role of tbg-1 expression was confirmed by the disruption of the gene expression by gamma-tubulin anti-sense RNA production in vivo under the heat shock promoter that caused lethality in the nematodes. Expression of tbg-1 deduced from Northern blot analysis during the development revealed differential expression in different developmental stages. Using tbg-1::lacZ fusion gene expression studies in the germ line transformed worms, it was further revealed that gamma-tubulin expression was observed through out the development from embryonic and post-embryonic stages.
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Affiliation(s)
- Mohammad Tabish
- Department of Material System Engineering, Toyohashi University of Technology, Toyohashi-Shi, Aichi-441, Japan.
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Farhadi A, Keshavarzian A, Ranjbaran Z, Fields JZ, Banan A. The role of protein kinase C isoforms in modulating injury and repair of the intestinal barrier. J Pharmacol Exp Ther 2005; 316:1-7. [PMID: 16002462 DOI: 10.1124/jpet.105.085449] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Gastrointestinal cells express a diverse group of protein kinase C (PKC) isoforms that play critical roles in a number of cell functions, including intracellular signaling and barrier integrity. PKC isoforms expressed by gastrointestinal epithelial cells consist of three major PKC subfamilies: conventional isoforms (alpha, beta1, beta2, and gamma), novel isoforms (delta, epsilon, theta, eta, and mu), and atypical isoforms (lambda, tau, and zeta). This review highlights recent discoveries, including our own, that some PKC isoforms in gastrointestinal epithelia monolayer cell culture are involved in injury to, whereas others are involved in protection of, intestinal barrier integrity. For example, certain PKC isoforms aggravate oxidative damage, whereas others protect against it. These findings suggest that the development of agents that selectively activate or inhibit specific PKC isoforms may lead to new therapeutic modalities for important gastrointestinal disorders such as cancer and inflammatory bowel disease.
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Affiliation(s)
- A Farhadi
- Section of Gastroenterology and Nutrition, Division of Digestive Diseases, Rush University Medical Center, 1725 W. Harrison, Suite 206, Chicago, IL 60612, USA.
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Kim S, Park JH, Koo SY, Kim JI, Kim MH, Kim JE, Jo K, Choi HG, Lee SB, Jung SH. Novel diarylsulfonylurea derivatives as potent antimitotic agents. Bioorg Med Chem Lett 2005; 14:6075-8. [PMID: 15546733 DOI: 10.1016/j.bmcl.2004.09.069] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2004] [Revised: 09/17/2004] [Accepted: 09/21/2004] [Indexed: 11/23/2022]
Abstract
A novel series of diarylsulfonylurea derivatives were synthesized and evaluated for interaction with tubulin and for cytotoxicity against human cancer cell lines. These derivatives demonstrated good inhibitory activity against tubulin polymerization, which was well correlated with promising antiproliferative activity as well as G2/M phase cell cycle arrest. Furthermore, several compounds were also efficacious against multidrug-resistant cancer cells, which are resistant to many other known microtubule inhibitors.
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Affiliation(s)
- Semi Kim
- LG Life Sciences, Ltd/R&D Park, 104-1 Moonji-dong, Yuseong-gu, Daejon 305-380, South Korea.
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Bailey SR, Polan JL, Munoz OC, Agrawal MC, Goswami NJ. Proliferation and β-tubulin for human aortic endothelial cells within gas-plasma scaffolds. ACTA ACUST UNITED AC 2004; 5:119-24. [PMID: 15721846 DOI: 10.1016/j.carrad.2004.08.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2004] [Revised: 08/14/2004] [Accepted: 08/14/2004] [Indexed: 11/29/2022]
Abstract
PURPOSE We determined if human aortic endothelial cells (HAEC) enhanced proliferative and angiogenic phenotypes within gas-plasma treated bioresorbable D,L-polylactic acid (D,L-PLA) three-dimensional scaffolds. METHOD 6 x 10(3) HAEC (N=120) were incubated for 6, 12 or 18 days within either non-treated control or treated scaffolds. Before removing media, unstained wells were observed for apparent cell densities. Quantitative colorimetric WST-1 mitochondrial assays were determined for pooled conditioned media from both HAEC attached to wells and their respective HAEC-containing scaffolds. Fixed HAEC in scaffolds were examined using non-quantitative laser confocal microcopy with FITC-conjugated consensus, Types-I/II or Type-III beta-tubulin. RESULTS WST-1 indicated that significantly (p<0.05) less mitochondria were on cell culture plates than inside scaffolds but for different reasons. For example, a 12-18 days comparison between WST-1 and beta-tubulin indicated that wells decreased because of overgrowth apotosis; whereas, mitochondrial activity inside treated scaffolds decreased with increased tubulogenesis. Observed with consensus and Type-I/II beta-tubulin, HAEC-treated scaffolds exhibited increased cell-cell interconnections and angiogenic cords undergoing tubulogenesis to form vessels with central lumens as well as increased Type-III beta-tubulin, predominantly in cells of smaller surface areas. Moreover, beta-tubulin inside HAEC-treated scaffolds appeared in discrete cytoskeletal and podial regions; yet, beta-tubulin for HAEC-control scaffolds was located in more diffuse cytoplasmic regions especially at 18 days. CONCLUSIONS HAEC-treated scaffolds undergo increased migration, proliferation, beta-tubulin expression and quiescent cord formation. HAEC in scaffolds represent a potential model to study mechanisms for vascular cord progression into tubes. WST-1 does not represent accurate cell densities in three-dimensional scaffold matrices.
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Affiliation(s)
- Steven R Bailey
- UTHSCSA: Janey Briscoe Center for Cardiovascular Research, 78229, USA.
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Affiliation(s)
- Michael Ellis
- Department of Medicine, Faculty of Medicine and Health Sciences, UAE Medical School, UAE University, Al Ain, United Arab Emirates.
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Shimoyama Y, Morikawa Y, Ichihara M, Kodama Y, Fukuda N, Hayashi H, Morinaga T, Iwashita T, Murakumo Y, Takahashi M. Identification of human SEP1 as a glial cell line-derived neurotrophic factor-inducible protein and its expression in the nervous system. Neuroscience 2003; 121:899-906. [PMID: 14580940 DOI: 10.1016/s0306-4522(03)00487-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Glial cell line-derived neurotrophic factor (GDNF) signals through multisubunit receptor complex consisting of RET tyrosine kinase and a glycosylphosphatidylinositol-anchored coreceptor called GDNF family receptor alpha1 (GFRalpha1). In the current study, we cloned a human SEP1 gene as a GDNF-inducible gene using human neuroblastoma cells that express RET and GFRalpha1. The induction of the SEP1 gene showed two peaks at 0.5-2 h and 24-48 h after GDNF stimulation by Northern blotting and quantitative real-time reverse transcriptase polymerase chain reaction. The late induction was also confirmed at protein levels by Western blotting with anti-SEP1 antibody. Immunostaining revealed that the expression of the SEP1 protein was detected in cell body, elongated neurites and growth cone-like structure of neuroblastoma cells treated with GDNF. In addition, we found a high level of SEP1 expression in neurons of the dorsal root and superior cervical ganglia and motor neurons of the spinal cord of mice in which RET is also expressed. SEP1 was co-immunoprecipitated with alpha- and beta-tubulins from the lysate of mouse brain. These results thus suggested that SEP1 is a GDNF-inducible and microtubule-associated protein that may play a role in the nervous system.
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Affiliation(s)
- Y Shimoyama
- Department of Pathology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan
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Huh JW, Raghupathi R, Laurer HL, Helfaer MA, Saatman KE. Transient Loss of Microtubule-Associated Protein 2 Immunoreactivity after Moderate Brain Injury in Mice. J Neurotrauma 2003; 20:975-84. [PMID: 14588114 DOI: 10.1089/089771503770195821] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Microtubule-associated protein 2 (MAP2) is important for microtubule stability and neural plasticity and appears to be among the most vulnerable of the cytoskeletal proteins under conditions of neuronal injury. To evaluate the acute effects of moderate severity traumatic brain injury on MAP2, anesthetized, adult male C57BL/6 mice were subjected to controlled cortical impact brain injury. At 5 min, 15 min, 90 min, 4 h, and 24 h following brain injury (n = 4 injured and n = 1 sham-injured per time point), mice were sacrificed and immunohistochemistry was performed on coronal brain sections. Profound decreases in MAP2 immunolabeling were observed in the ipsilateral cortex and hippocampal dentate hilus at 5 min postinjury and in the ipsilateral hippocampal CA3 area by 4 h postinjury. Decreases in MAP2 labeling occurred prior to notable neuronal cell loss. Interestingly, cortical MAP2 immunoreactivity returned by 90 min postinjury, but the recovery was short-lived within the core in comparison to the periphery of the impact site. Partial restoration of MAP2 immunoreactivity was also observed in the ipsilateral CA3 and dentate hilus by 24 h postinjury. Our data corroborate that MAP2 is an early and sensitive marker for neuronal damage following traumatic brain injury. Acute MAP2 loss, however, may not necessarily presage neuronal death, even following moderate severity traumatic brain injury. Rather, to the best of our knowledge, our data are the first to suggest an intrinsic ability of the traumatized brain for MAP2 recovery after injury of moderate severity.
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Affiliation(s)
- Jimmy W Huh
- Department of Anesthesia and Critical Care, The Children's Hospital of Philadelphia, Pennsylvania, USA
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Abstract
Chemical genetics is a research approach that uses small molecules as probes to study protein functions in cells or whole organisms. Here, I review the parallels between classical genetic and chemical-genetic approaches and discuss the merits of small molecules to dissect dynamic cellular processes. I then consider the pros and cons of different screening approaches and specify strategies aimed at identifying and validating cellular target proteins. Finally, I highlight the impact of chemical genetics on our current understanding of cell biology and its potential for the future.
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Affiliation(s)
- Thomas U Mayer
- Max Planck Institute of Biochemistry, Department of Cell Biology, Am Klopfersitz 18a, D-82152 Martinsried, Germany.
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42
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Abstract
The intestine constitutes the largest interface between a person and his or her environment, and an intact intestinal barrier is thus essential in maintaining health and preventing tissue injury and several diseases. The intestinal barrier has various immunological and non-immunological components. The epithelial barrier is one of the most important non-immunological components. Hyperpermeability of this barrier is believed to contribute to the pathogenesis of several gastrointestinal disorders including inflammatory bowel disease, celiac disease and food allergy. Hence, assessing barrier integrity is of the utmost importance. One of the more quantitative gauges for this assessment is transepithelial permeability of various molecular probes, among which sugars are commonly used. Measures of intestinal permeability might also be useful as markers for assessment of prognosis and follow up in various gastrointestinal disorders. The present article is a review of the normal and abnormal functioning of the intestinal barrier, the diseases that can result from loss of barrier integrity, and some promising agents and strategies for restoring barrier normality and integrity.
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Affiliation(s)
- Ashkan Farhadi
- Department of Internal Medicine (Section of Gastroenterology and Nutrition), Rush University Medical Center, Chicago, Illinois 60612, USA.
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43
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Liu Y, Saad RS, Shen SS, Silverman JF. Diagnostic value of microtubule-associated protein-2 (MAP-2) for neuroendocrine neoplasms. Adv Anat Pathol 2003; 10:101-6. [PMID: 12605092 DOI: 10.1097/00125480-200303000-00005] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Microtubule associated proteins (MAPs) are major components of cytoskeleton proteins associated with microtubule assembly. Microtubule associated protein-2 (MAP-2), a component of the MAP family, has been shown to be specifically expressed in neuronally differentiated cells, and has been previously used as a sensitive and specific marker for neurons. Immunoreactivity of MAP-2 has been demonstrated in most neuroendocrine and neuroectodermal related neoplasms such as small cell carcinoma, large cell neuroendocrine carcinoma, carcinoid tumor of the lung, Merkel cell carcinoma of the skin, medulloblastoma, neurocytoma of the central nervous system, extrapulmonary small cell carcinoma and carcinoid tumor, and malignant melanomas. This report details the diagnostic value of MAP-2 on tumors with neuroendocrine differentiation and neoplasms derived from the neural crest.
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Affiliation(s)
- Yulin Liu
- Department of Pathalogy and Laboratory Medicine, Allegheny General Hospital, Pittsburgh, Pennsylvania 15212, USA
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Ho WH, Wang SM, Yin HS. Acrylamide disturbs the subcellular distribution of GABAA receptor in brain neurons. J Cell Biochem 2002; 85:561-71. [PMID: 11967996 DOI: 10.1002/jcb.10159] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Mechanisms underlying the action of acrylamide on neurons were studied by monitoring the expression of GABA(A) receptor (R) in cultured brain neurons derived from chicken embryos. In situ trypsinization of the neurons and 3H-flunitrazepam binding assay were employed to examine the subcellular distribution of GABA(A)R. A 3-h exposure of the cultured neurons to 10 mM of acrylamide raised reversibly the proportion of intracellular (trypsin-resistant) 3H-flunitrazepam binding sites by about 48% and decreased cell surface binding 24% from respective control values, without altering total cellular binding and the affinity of the ligand. Moreover, the acrylamide treatment induced more intense perikaryal immunostaining of GABA(A)R alpha subunit proteins than that in control neurons but did not change the total level of cellular alpha immunostain, in accordance with the binding data. In the cell bodies of acrylamide-treated neurons, the level of neurofilament-200 kDa proteins was similar to control, whereas the tubulin protein content was significantly lowered approximately 51% from control, as revealed by quantifying the immunostained cytoskeletal elements. In addition, electron microscopic observations found reductions in the numbers of microtubules and neurofilaments in the perikarya of acrylamide-treated neurons. As exhibited by the 3H-leucine and 3H-monosaccharide incorporation experiments, the exposure to acrylamide inhibited the rate of general protein synthesis in the culture by 21%, while the rate of glycosylation remained unaltered. Furthermore, in situ hybridization analysis showed that acrylamide did not modify the expression of GABA(A)R alpha subunit mRNAs. Taken together, these data suggest that acrylamide may downregulate the microtubular system and disintegrate neurofilaments, and thereby block the intracellular transport of GABA(A)R, resulting in the accumulation of intracellular receptors.
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Affiliation(s)
- Wen-Hsin Ho
- Department of Anatomy and Cell Biology, College of Medicine, National Taiwan University, Taipei, Taiwan, Republic of China
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45
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Kaur G, Heera PK, Srivastava LK. Neuroendocrine plasticity in GnRH release during rat estrous cycle: correlation with molecular markers of synaptic remodeling. Brain Res 2002; 954:21-31. [PMID: 12393229 DOI: 10.1016/s0006-8993(02)03301-2] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Morphological changes in the gonadotropin releasing hormone (GnRH) neurons in the preoptic area (POA) and their terminals in the median eminence-arcuate (ME-ARC) region are reported to occur during ovarian cycle that may be involved in the GnRH release into the portal blood during preovulatory surge. However, the neuronal substrates participating in altered GnRH neuronal plasticity are poorly understood. The present study was designed to determine whether morphological changes occurring in the GnRH neuron cell bodies in the POA and their terminals in the ME-ARC region of hypothalamus with pulsatile GnRH release in cycling female rats are associated with expression of intrinsic determinants of neuronal plasticity. The plasticity markers studied are polysialylated neural cell adhesion molecule (PSA-NCAM), high molecular weight isoforms of NCAM, growth associated protein (GAP-43), glial fibrillary acidic protein (GFAP) and synaptophysin. Regularly cycling female rats were sacrificed at diestrous, i.e., when GnRH release is low, and at proestrous, i.e., when preovulatory GnRH surge occurs, using perfusion fixation method for immunohistochemical staining of GnRH cells. GnRH cell bodies and their terminals from the POA and ME-ARC region respectively, were localized using immunohistochemical technique in proestrous and diestrous phase of estrous cycle and our results showed a marked increase in the GnRH nerve terminals length and immunoreactivity in the ME-ARC region from proestrous phase rats as compared to diestrous rats. Immunoblot analyses of the POA and ME-ARC region of the hypothalamus revealed a significant increase in the content of PSA-NCAM, NCAM-180, NCAM-140, GAP-43 and synaptophysin from proestrous phase rats as compared to diestrous phase rats. The ME-ARC region showed more pronounced increase in the protein expression of these markers of neuronal plasticity as compared to the POA, whereas, hippocampal region did not show any significant change in the content of these markers showing specificity of the changes to the GnRH system. GFAP content was significantly decreased in the POA with a marginal increase in the GFAP level from the ME-ARC region. These results demonstrate the involvement of synaptic proteins in the dynamic plasticity of the ME-ARC region of hypothalamus, allowing GnRH nerve terminals to release the neurohormone into the pituitary portal blood on the day of proestrous.
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Affiliation(s)
- Gurcharan Kaur
- Neurochemistry and Neuroendocrinology Laboratory, Department of Biotechnology, Guru Nanak Dev University, Amritsar 143005 (Pb), India.
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Takano Y, Oshiro E, Okuno T. Microtubule dynamics during infection-related morphogenesis of Colletotrichum lagenarium. Fungal Genet Biol 2001; 34:107-21. [PMID: 11686676 DOI: 10.1006/fgbi.2001.1293] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Using a green fluorescent protein (GFP)-tubulin fusion protein, we have investigated the dynamic rearrangement of microtubules during appressorium formation of Colletotrichum lagenarium. Two alpha-tubulin genes of C. lagenarium were isolated, and GFP-alpha-tubulin protein was expressed in this fungus. The strain expressing the fusion protein formed fluorescent filaments that were disrupted by a microtubule-depolymerizing drug, benomyl, demonstrating successful visualization of microtubules. In preincubated conidia, GFP-labeled interphase microtubules, showing random orientation, were observed. At conidial germination, microtubules oriented toward a germination site. At nuclear division, when germ tubes had formed appressoria, mitotic spindles appeared inside conidia followed by disassembly of interphase microtubules. Remarkably, time-lapse views showed that interphase microtubules contact a microtubule-associated center at the cell cortex of conidia that is different from a nuclear spindle pole body (SPB) before their disassembly. Duplicated nuclear SPBs separately moved toward conidium and appressorium accompanied by astral microtubule formation. Benomyl treatment caused movement of both daughter nuclei into 70% of appressoria and affected appressorium morphogenesis. In conidia elongating hyphae without appressoria, microtubules showed polar elongation which is distinct from their random orientation inside appressoria.
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Affiliation(s)
- Y Takano
- Laboratory of Plant Pathology, Kyoto University, Kyoto, 606-8502, Japan.
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Kobayashi J, Suzuki H, Shimbo K, Takeya K, Morita H. Celogentins A-C, new antimitotic bicyclic peptides from the seeds of Celosia argentea. J Org Chem 2001; 66:6626-33. [PMID: 11578213 DOI: 10.1021/jo0103423] [Citation(s) in RCA: 109] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Three new bicyclic peptides, celogentins A (1), B (2), and C (3), have been isolated together with a known-related peptide, moroidin (4), from the seeds of Celosia argentea, and their structures including absolute stereochemistry were determined by using extensive NMR methods and chemical means. Celogentins A (1), B (2), and C (3) inhibited the polymerization of tubulin, and celogentin C (3) was four times more potent than moroidin (4) in the inhibitory activity. Structure-activity relationship study using moroidin derivatives 5-7 and analogue 8 as well as celogentins A-C (1-3) and moroidin (4) indicates that the bicyclic ring system including unusual non-peptide connections among beta(s)-Leu, Trp, and His residues characteristic of celogentins and moroidin, with ring size and conformations suitable for interaction with tubulin would be important for their biological activity.
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Affiliation(s)
- J Kobayashi
- Graduate School of Pharmaceutical Sciences, Hokkaido University, Sapporo 060-0812, Japan.
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48
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Liu Y, Sturgis CD, Grzybicki DM, Jasnosz KM, Olson PR, Tong M, Dabbs DD, Raab SS, Silverman JF. Microtubule-associated protein-2: a new sensitive and specific marker for pulmonary carcinoid tumor and small cell carcinoma. Mod Pathol 2001; 14:880-5. [PMID: 11557784 DOI: 10.1038/modpathol.3880406] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Microtubule-associated proteins (MAPs) are a major component of cytoskeleton family proteins associated with microtubule assembly. MAP-2 has been shown to be specifically expressed in neuronally differentiated cells. Pulmonary neuroendocrine carcinomas such as carcinoid tumors and small cell carcinomas are derived from neuroendocrine cells. We hypothesize that neuroendocrine cells may also express MAP-2, and therefore, MAP-2 may be used as a marker for pulmonary carcinomas of neuroendocrine differentiation. To investigate the utility of using MAP-2 expression to separate pulmonary neuroendocrine from non-neuroendocrine tumors, we examined the expression of MAP-2 immunohistochemically in 100 cases of pulmonary carcinomas. The immunoperoxidase method with antigen retrieval was used to characterize the expression of MAP-2, chromogranin, synaptophysin, and neuron-specific enolase in 25 small cell carcinomas, 25 carcinoid tumors, 25 adenocarcinomas, and 25 squamous cell carcinomas. All tumors were lung primaries. All 25 cases of carcinoid tumors (100%) as well as 23 of 25 cases (92%) of small cell carcinomas were positive for MAP-2. Four of 25 cases (16%) of adenocarcinomas were positive for MAP-2 and synaptophysin. Among the 25 squamous carcinomas, 4 cases (16%) were positive for MAP-2, 2 cases (8%) were positive for synaptophysin, 11 cases (44%) were positive for neuron-specific enolase, and none was positive for chromogranin. In conclusion, MAP-2 is a new sensitive and specific marker for the pulmonary tumors of neuroendocrine differentiation. We recommend that MAP-2 be added to immunohistochemical panels to separate non-neuroendocrine from neuroendocrine lung tumors.
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Affiliation(s)
- Y Liu
- Department of Pathology and Laboratory Medicine, Allegheny General Hospital, Pittsburgh, Pennsylvania 15212, USA.
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49
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Vallarino-Kelly T, Morales-Ramírez P. Kinetics of micronucleus induction and cytotoxic activity of colchicine in murine erythroblast in vivo. Mutat Res 2001; 495:51-9. [PMID: 11448642 DOI: 10.1016/s1383-5718(01)00195-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
In previous studies, we inferred some pharmacokinetic and pharmacodynamic parameters of alkylating agents and antimetabolites by comparing their kinetics of micronucleated polychromatic erythrocyte (MN-PCE) induction with the one obtained after the exposure to gamma rays in peripheral blood of mice, assuming that radiation acts immediately because it does not require absorption and distribution in the organism. According to our earlier studies, the kinetics of MN-PCE induction depends mainly on the following: (i) the cytotoxic effects that in turn could affect the duration of cell division; (ii) the pharmacokinetics including the metabolic activation requirement; and (iii) the mechanism of MN induction. The aim of the present study was to analyze the kinetics of MN-PCE induction by an aneuploidogen that induces micronuclei by acting on the achromatic spindle. The kinetics of MN-PCE induction by colchicine, as well as the reduction in the PCE frequency over time was determined in peripheral blood of mice treated with different doses of the aneuploidogen. The genotoxic effect, established as the area beneath the curve (ABC) of MN-PCE versus time-response, indicates an almost directly proportional relationship with respect to dose. Similarly, the relationship between dose and cytotoxic effect determined as the ABC of PCE versus time was inversely proportional, suggesting a relationship between both endpoints and doses administered. However, the number of cells affected by these two phenomena indicates that cytotoxicity is not necessarily caused, or at least not only by genotoxicity. The analysis of the kinetics of MN-PCE induction after the treatment with non-cytotoxic dose of colchicine, indicates that the MN-PCE appear in the blood stream at almost the same time, as occurs after the exposure to gamma rays; in spite of the differences in the cell cycle stage in which they can cause micronucleus (MN). Perhaps the fact that cells are not synchronized does not permit one to observe some difference in the time they appear in the blood. These results suggest that colchicine acts rapidly after exposure. The elimination half-life of colchicine is 17h, suggesting that colchicne is disposable for long time. With high doses of colchicine the pharmacokinetic parameters increases substantially. These data imply that low doses of colchicine are slightly cytotoxic, and that under this circumstances colchicines arrives rapidly to hemopoyetic tissues and acts for several hours.
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Affiliation(s)
- T Vallarino-Kelly
- Departamento de Biología, Instituto Nacional de Investigaciones Nucleares, Apartado Postal 18-1027 Mexico D.F., Mexico
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50
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Ho WH, Wang SM, Yin HS. Regulation of the subcellular distribution and gene expression of GABA(A) receptor by microtubules and microfilaments in cultured brain neurons. J Cell Biochem 2001; 83:291-303. [PMID: 11573246 DOI: 10.1002/jcb.1232] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Mechanisms underlying the intracellular transport of gamma-aminobutyric acid(A) receptor (GABA(A)R) were examined in the cultured neurons derived from chicken embryo brains. In situ trypsinization of the cultures and (3)H-flunitrazepam (FNZ) binding assay were employed to determine the cell surface and intracellular distribution of the receptor. A 3-h treatment of the cells with 1 microM of colchicine, a microtubule depolymerizer, reversibly raised the proportion of intracellular GABA(A)R density by about 36% and decreased that of the cell surface receptors by 18% from respective control values, whereas the 3-h incubation with 2 microM of cytochalasin D, a microfilament disrupter, did not cause significant changes. These treatments failed to alter the total number of the (3)H-FNZ binding sites of the neurons and the affinity of the ligand. Moreover, the exposure to colchicine seemed to produce a stronger cytoplasmic immunostaining of the GABA(A)R alpha subunits in many neurons without affecting the total cellular level of the proteins, in accordance with the increased fraction of intracellular (3)H-FNZ binding. However, in the neurons exposed to cytochalasin D, there was an increase of around 28% in the total content of alpha(1)+51kDa proteins. In addition, the colchicine or cytochalasin D treatment inhibited approximately 21 or 18% of the rate of general protein synthesis in the culture. Notably, in situ hybridization assay showed that the GABA(A)R alpha(1) or alpha(2) mRNA was present in 92 +/- 2% or 94 +/- 2% of the cytochalasin D-treated neurons, both of which were higher than 71 +/- 2-74 +/- 3% of the control and colchicine-treated cells. The data suggest that by regulating the intracellular transport, the microtubular system participates in the maintenance of normal subcellular distribution of GABA(A)R in the neurons. By contrast, the organization of microfilaments may play a role in modulating the gene expression of GABA(A)R subunits.
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Affiliation(s)
- W H Ho
- Department of Anatomy and Cell Biology, College of Medicine, National Taiwan University, Taipei, Taiwan, Republic of China
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