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Yang J, Li H, Qin Y, Li J. [Effects of conditioned medium of alveolar epithelial cells on vascular endothelial cell damage]. Zhonghua Wei Zhong Bing Ji Jiu Yi Xue 2024; 36:160-165. [PMID: 38442932 DOI: 10.3760/cma.j.cn121430-20230529-00403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/07/2024]
Abstract
OBJECTIVE To observe the effect of lipopolysaccharide (LPS) induced conditioned medium of alveolar epithelial cells on the inflammatory response and cell damage of vascular endothelial cells, and explore its mechanism. METHODS The LPS induced type II alveolar epithelial cells (A549) conditioned medium was used as a stimulus to induce human umbilical vein endothelial cells (HUVEC) damage. The cell counting kit-8 (CCK-8) was used to detect the effect of 0% (blank group), 12.5%, 25%, 50%, 75% and 100% A549 cell conditioned medium cultured for 6, 12, 24 and 48 hours on the cell viability of HUVEC. Enzyme-linked immunosorbent assay (ELISA) was used to detect the levels of inflammatory factors [interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α)] and vasoactive substances [vascular endothelial growth factor (VEGF), endothelin-1 (ET-1)] in the supernatant. Phalloidin staining was used to observe the effects of A549 cells conditioned medium on cell morphology. The expressions of protein kinase B/nuclear factor-κB (AKT/NF-κB) pathway in HUVEC induced by conditioned medium was detected by Western blotting. RESULTS Compared with the blank group, A549 cells conditioned medium with concentrations of 12.5%, 25%, and 50% had no significant effects on cell viability of HUVEC after 6, 12, and 24 hours, but the activity of HUVEC decreased significantly after 48 hours. Therefore, 12.5%, 25%, 50% A549 cell conditioned medium stimulated for 24 hours was selected as the induction condition for follow-up experiments. Compared with the blank group, the level of IL-6 was significantly increased in 12.5% and 50% conditioned medium groups (ng/L: 2 438.95±64.89, 3 036.41±96.69 vs. 1 736.75±20.99, both P < 0.05), the level of TNF-α was significantly increased in 12.5% and 25% conditioned medium groups (ng/L: 174.08±11.09, 81.37±8.17 vs. 50.03±0.26, both P < 0.01), the levels of VEGF and ET-1 were significantly increased in 12.5%, 25% and 50% conditioned medium groups [VEGF (ng/L): 173.60±41.44, 192.49±12.38, 318.89±27.90 vs. 66.68±19.65; ET-1 (ng/L): 54.88±1.37, 36.69±0.29, 24.07±0.73 vs. 10.67±0.25, all P < 0.01]. Phalloidin staining showed that HUVEC induced by 25% A549 cells conditioned medium were irregular in shape, uneven in size, disordered in arrangement, widened in gap, dense and unclear in microfilament structure and serrated in cell membrane. Furthermore, the average fluorescence intensity of 25% conditioned medium group significantly increased compared to the blank group (67 205.60±3 430.40 vs. 56 272.67±7 650.95, P < 0.05). Western blotting showed that compared with the blank group, the expression of HUVEC cells phosphonated inhibitor α of NF-κB (p-IκBα) was significantly decreased in the 12.5%, 25%, and 50% conditioned medium groups (p-IκBα/IκBα: 0.38±0.08, 0.67±0.12, 0.31±0.07 vs. 1.00±0.00, all P < 0.01), the expressions of phosphonated-AKT (p-AKT) and VEGF were significantly increased (p-AKT/AKT: 1.50±0.18, 1.42±0.27, 1.61±0.14 vs. 1.00±0.00, VEGF/GAPDH: 1.37±0.10, 1.53±0.22, 1.40±0.12 vs. 1.00±0.00, all P < 0.05), the expression of phosphonated NF-κB p65 (p-P65) was significantly increased in the 25% conditioned medium group (p-P65/P65: 1.45±0.14 vs. 1.00±0.00, P < 0.05). CONCLUSIONS LPS induced conditional culture medium of alveolar epithelial cells induced endothelial cell damage via activating AKT/NF-κB pathway.
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Affiliation(s)
- Jingfan Yang
- Academy of Chinese Medical Sciences, Henan University of Chinese Medicine, Zhengzhou 450046, Henan, China
- Henan Key Laboratory of Chinese Medicine for Respiratory Disease, Co-construction Collaborative Innovation Center for Chinese Medicine and Respiratory Diseases by Henan and Education Ministry of P.R., Henan University of Chinese Medicine, Zhengzhou 450046, Henan, China
| | - Haibo Li
- Academy of Chinese Medical Sciences, Henan University of Chinese Medicine, Zhengzhou 450046, Henan, China
- Henan Key Laboratory of Chinese Medicine for Respiratory Disease, Co-construction Collaborative Innovation Center for Chinese Medicine and Respiratory Diseases by Henan and Education Ministry of P.R., Henan University of Chinese Medicine, Zhengzhou 450046, Henan, China
| | - Yanqin Qin
- Academy of Chinese Medical Sciences, Henan University of Chinese Medicine, Zhengzhou 450046, Henan, China
- Henan Key Laboratory of Chinese Medicine for Respiratory Disease, Co-construction Collaborative Innovation Center for Chinese Medicine and Respiratory Diseases by Henan and Education Ministry of P.R., Henan University of Chinese Medicine, Zhengzhou 450046, Henan, China
| | - Jiansheng Li
- Henan Key Laboratory of Chinese Medicine for Respiratory Disease, Co-construction Collaborative Innovation Center for Chinese Medicine and Respiratory Diseases by Henan and Education Ministry of P.R., Henan University of Chinese Medicine, Zhengzhou 450046, Henan, China
- Department of Respiratory and Critical Care Medicine, the First Affiliated Hospital of Henan University of Chinese Medicine, Zhengzhou 450003, Henan, China. Corresponding author: Qin Yanqin,
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Zhao S, Cui J, Wang Y, Xu D, Su Y, Ma J, Gong X, Bai W, Wang J, Cao R. Three-dimensional visualization of the lymphatic, vascular and neural network in rat lung by confocal microscopy. J Mol Histol 2023; 54:715-723. [PMID: 37755618 DOI: 10.1007/s10735-023-10160-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Accepted: 09/18/2023] [Indexed: 09/28/2023]
Abstract
In order to demonstrate the intricate interconnection of pulmonary lymphatic vessels, blood vessels, and nerve fibers, the rat lung was selected as the target and sliced at the thickness of 100 μm for multiply immunofluorescence staining with lymphatic vessel endothelial hyaluronan receptor 1 (LYVE-1), alpha smooth muscle actin (α-SMA), phalloidin, cluster of differentiation 31 (CD31), and protein gene product 9.5 (PGP9.5) antibodies. Taking the advantages of the thicker tissue section and confocal microscopy, the labeled pulmonary lymphatic vessels, blood vessels, and nerve fibers were demonstrated in rather longer distance, which was more convenient to reconstruct a three-dimensional (3D) view for analyzing their spatial correlation in detail. It was clear that LYVE-1+ lymphatic vessels were widely distributed in pulmonary lobules and closely to the lobar bronchus. Through 3D reconstruction, it was also demonstrated that LYVE-1+ lymphatic vessels ran parallel to or around the α-SMA+ venules, phalloidin+ arterioles and CD31+ capillaries, with PGP9.5+ nerve fibers traversing alongside or wrapping around them, forming a lymphatic, vascular and neural network in the lung. By this study, we provide a detailed histological view to highlight the spatial correlation of pulmonary lymphatic, vascular and neural network, which may help us for insight into the functional role of this network under the physiological and pathological conditions.
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Affiliation(s)
- Shitong Zhao
- Department of Traditional Chinese Medicine, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, 100020, China
| | - Jingjing Cui
- Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, 100700, China
| | - Yuqing Wang
- Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, 100700, China
| | - Dongsheng Xu
- Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, 100700, China
| | - Yuxin Su
- Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, 100700, China
| | - Jie Ma
- Beijing Hospital of Integrated Traditional Chinese and Western Medicine, Beijing, 100038, China
| | - Xuefeng Gong
- Department of Traditional Chinese Medicine, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, 100020, China
| | - Wanzhu Bai
- Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, 100700, China
| | - Jia Wang
- Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, 100700, China.
| | - Rui Cao
- Department of Traditional Chinese Medicine, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, 100020, China.
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Lim CH, Song IS, Lee J, Lee MS, Cho YY, Lee JY, Kang HC, Lee HS. Toxicokinetics and tissue distribution of phalloidin in mice. Food Chem Toxicol 2023; 179:113994. [PMID: 37598851 DOI: 10.1016/j.fct.2023.113994] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 08/15/2023] [Accepted: 08/16/2023] [Indexed: 08/22/2023]
Abstract
Phalloidin, a bicyclic heptapeptide found in Amanita mushroom, specifically binds to F-actin in the liver causing cholestatic hepatotoxicity. However, the toxicokinetics and tissue distribution properties of phalloidin as well as their underlying mechanisms have to be studied further. The area under the plasma concentration curve (AUC) of phalloidin increased in proportion to the doses (0.2, 0.4, and 0.8 mg/kg for intravenous injection and 2, 5, and 10 mg/kg for oral administration). Phalloidin exhibited dose-independent low volume of distribution (395.6-456.9 mL/kg) and clearance (21.4-25.5 mL/min/kg) and low oral bioavailability (2.4%-3.3%). This could be supported with its low absorptive permeability (0.23 ± 0.05 × 10-6 cm/s) in Caco-2 cells. The tissue-to-plasma AUC ratios of intravenously injected and orally administered phalloidin were the highest in the liver and intestines, respectively, and also high in the kidneys, suggesting that the liver, kidneys, and intestines could be susceptible to phalloidin exposure and that active transport via the hepatic and renal organic anion transporters (OATP1B1, OATP1B3, and OAT3) may contribute to the higher distribution of phalloidin in the liver and kidneys.
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Affiliation(s)
- Chang Ho Lim
- College of Pharmacy and BK21 Four-sponsored Advanced Program for SmartPharma Leaders, The Catholic University of Korea, Bucheon, 14662, Republic of Korea.
| | - Im-Sook Song
- BK21 FOUR Community-Based Intelligent Novel Drug Discovery Education Unit, Vessel-Organ Interaction Research Center (VOICE), Research Institute of Pharmaceutical Sciences, College of Pharmacy, Kyungpook National University, Daegu, 41566, Republic of Korea.
| | - Jihoon Lee
- BK21 FOUR Community-Based Intelligent Novel Drug Discovery Education Unit, Vessel-Organ Interaction Research Center (VOICE), Research Institute of Pharmaceutical Sciences, College of Pharmacy, Kyungpook National University, Daegu, 41566, Republic of Korea.
| | - Min Seo Lee
- College of Pharmacy and BK21 Four-sponsored Advanced Program for SmartPharma Leaders, The Catholic University of Korea, Bucheon, 14662, Republic of Korea.
| | - Yong-Yeon Cho
- College of Pharmacy and BK21 Four-sponsored Advanced Program for SmartPharma Leaders, The Catholic University of Korea, Bucheon, 14662, Republic of Korea.
| | - Joo Young Lee
- College of Pharmacy and BK21 Four-sponsored Advanced Program for SmartPharma Leaders, The Catholic University of Korea, Bucheon, 14662, Republic of Korea.
| | - Han Chang Kang
- College of Pharmacy and BK21 Four-sponsored Advanced Program for SmartPharma Leaders, The Catholic University of Korea, Bucheon, 14662, Republic of Korea.
| | - Hye Suk Lee
- College of Pharmacy and BK21 Four-sponsored Advanced Program for SmartPharma Leaders, The Catholic University of Korea, Bucheon, 14662, Republic of Korea.
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Petrov AA, Dmitrieva EV, Plaksina MP. Neuromuscular organization and haptoral armament of Polyclithrum ponticum (Monogenea: Gyrodactylidae). J Helminthol 2022; 96:e74. [PMID: 36226664 DOI: 10.1017/s0022149x22000608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Most gyrodactylids have a haptor armed with a pair of hamuli, two connecting bars and 16 marginal hooks. In some gyrodactylids, however, the haptor is disc-shaped and reinforced by additional sclerites. The genus Polyclithrum has arguably the most elaborate haptor in this group. This study aimed to gain better understanding of the anatomy of Polyclithrum by examining neuromusculature and haptoral armament of Polyclithrum ponticum, a species parasitizing Mugil cephalus in the Black Sea, with emphasis on haptoral sclerites and musculature in connection with host-attachment mechanisms. Musculature was stained by phalloidin, the nervous system by anti-serotonin and anti-FMRFamide antibodies, and haptoral sclerites were visualized in reflected light. The study provided new information on sclerites: in addition to previously described supplementary sclerites (A1-6), ear-shaped sclerites (ESSs) and two paired groups of ribs, reflected light revealed a rod-shaped process on the ESSs and a pair of small posterior sclerites. The sclerites were shown to be operated by 16 muscles, the most prominent of which were two transverse muscles connecting the hamular roots, three muscles attached to sclerite A2, the muscle fibres of anterior ribs and a set of extrinsic muscles. The nervous system consists of a pair of cerebral ganglia connected by a commissure and three pairs of nerve cords that unite in the haptor to form a loop between the opposite cords. The arrangement of sclerites and muscles suggests that Polyclithrum initiates the attachment by clamping a host's surface with longitudinally folded haptor and then secures its position with marginal hooks.
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Affiliation(s)
- A A Petrov
- Zoological Institute, Saint-Petersburg, Russia
| | - E V Dmitrieva
- A.O. Kovalevsky Institute of Biology of the Southern Seas, Moscow, Russia
| | - M P Plaksina
- Murmansk Marine Biological Institute, Murmansk, Russia
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Cesca K, Oliveira EM. Confocal Laser Microscopy for VM Analysis with DAPI and Phalloidin Staining. Methods Mol Biol 2022; 2514:153-161. [PMID: 35771427 DOI: 10.1007/978-1-0716-2403-6_15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Confocal laser scanning microscopy (CLSM) is one of the most prevalent fluorescence microscopy techniques for assessing the progression of cancer cells in three-dimensional structures, such as vasculogenic mimicry (VM). We show a basic approach for using DAPI and phalloidin dyes to detect the early stages of progression and VM of melanoma tumor cells grown in a 3D environment, as well as demonstrating how to acquire images and improve them by changing the software acquisition parameters.
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Affiliation(s)
- Karina Cesca
- Department of Chemical and Food Engineering, Federal University of Santa Catarina - UFSC, Florianópolis, SC, Brazil.
| | - Eliana Medeiros Oliveira
- Central Laboratory of Electron Microscopy, Pro Rectory of Research, Federal University of Santa Catarina, Florianópolis, SC, Brazil
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Wang C, Lambert C, Hauser M, Deuschmann A, Zeilinger C, Rottner K, Stradal TEB, Stadler M, Skellam EJ, Cox RJ. Diversely Functionalised Cytochalasins through Mutasynthesis and Semi-Synthesis. Chemistry 2020; 26:13578-13583. [PMID: 32484589 PMCID: PMC7692911 DOI: 10.1002/chem.202002241] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Indexed: 11/11/2022]
Abstract
Mutasynthesis of pyrichalasin H from Magnaporthe grisea NI980 yielded a series of unprecedented 4'-substituted cytochalasin analogues in titres as high as the wild-type system (≈60 mg L-1 ). Halogenated, O-alkyl, O-allyl and O-propargyl examples were formed, as well as a 4'-azido analogue. 4'-O-Propargyl and 4'-azido analogues reacted smoothly in Huisgen cycloaddition reactions, whereas p-Br and p-I compounds reacted in Pd-catalysed cross-coupling reactions. A series of examples of biotin-linked, dye-linked and dimeric cytochalasins was rapidly created. In vitro and in vivo bioassays of these compounds showed that the 4'-halogenated and azido derivatives retained their cytotoxicity and antifungal activities; but a unique 4'-amino analogue was inactive. Attachment of larger substituents attenuated the bioactivities. In vivo actin-binding studies with adherent mammalian cells showed that actin remains the likely intracellular target. Dye-linked compounds revealed visualisation of intracellular actin structures even in the absence of phalloidin, thus constituting a potential new class of actin-visualisation tools with filament-barbed end-binding specificity.
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Affiliation(s)
- Chongqing Wang
- Institute for Organic Chemistry and BMWZLeibniz University of HannoverSchneiderberg 3830167HannoverGermany
| | - Christopher Lambert
- Department Microbial DrugsHelmholtz Centre for Infection Research, Bldg. B, Room 175aInhoffenstrasse 738124BraunschweigGermany
- Division of Molecular Cell BiologyZoological InstituteTechnische Universität BraunschweigSpielmannstrasse 738106BraunschweigGermany
| | - Maurice Hauser
- Institute for Organic Chemistry and BMWZLeibniz University of HannoverSchneiderberg 3830167HannoverGermany
| | - Adrian Deuschmann
- Institute for Organic Chemistry and BMWZLeibniz University of HannoverSchneiderberg 3830167HannoverGermany
| | - Carsten Zeilinger
- Institute for Organic Chemistry and BMWZLeibniz University of HannoverSchneiderberg 3830167HannoverGermany
| | - Klemens Rottner
- Department of Cell BiologyHelmholtz Centre for Infection ResearchInhoffenstrasse 738124BraunschweigGermany
- Division of Molecular Cell BiologyZoological InstituteTechnische Universität BraunschweigSpielmannstrasse 738106BraunschweigGermany
| | - Theresia E. B. Stradal
- Department of Cell BiologyHelmholtz Centre for Infection ResearchInhoffenstrasse 738124BraunschweigGermany
| | - Marc Stadler
- Department Microbial DrugsHelmholtz Centre for Infection Research, Bldg. B, Room 175aInhoffenstrasse 738124BraunschweigGermany
| | - Elizabeth J. Skellam
- Institute for Organic Chemistry and BMWZLeibniz University of HannoverSchneiderberg 3830167HannoverGermany
| | - Russell J. Cox
- Institute for Organic Chemistry and BMWZLeibniz University of HannoverSchneiderberg 3830167HannoverGermany
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Mair GR, Halton DW, Maule AG. The neuromuscular system of the sheep tapeworm Moniezia expansa. Invert Neurosci 2020; 20:17. [PMID: 32978688 DOI: 10.1007/s10158-020-00246-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Accepted: 08/05/2020] [Indexed: 01/06/2023]
Abstract
Cestodes are common gastrointestinal parasites of humans and livestock. They attach to the host gut and, without a mouth or intestinal system, absorb nutrients through their epidermis. Here we show that despite this simplified anatomy and sessile lifestyle, they maintain a complex neuromuscular system. We used fluorescently labelled phalloidin as a specific probe for filamentous actin to define the overall organisation of several distinct muscle systems in the cyclophyllidean Moniezia expansa. Like all flatworms, the body wall musculature below the neodermis of this intestinal parasite of sheep is characterised by outer circular and inner longitudinal muscle fibres. Diagonal fibres, typically found in free-living and trematode platyhelminths, on the other hand, are notably absent. Prominent longitudinal sheaths dominate the parenchyma and provide retractor muscles to the four acetabula in the scolex; they attach at the bottom of each cup-shaped holdfast. Within sexually mature proglottids, circular fibres dominate the duct walls of the male and female reproductive systems. Nerve cells and fibres that express serotonin or neuropeptide F supply well-developed innervation to several of the described muscle systems: emanating from the central nervous system, fibres in the periphery develop pervasive nerve nets that anastomose within body wall musculature as well as the parenchymal longitudinal and oblique muscle fibres, and innervate the sexual organs and gonopore in mature proglottids. Using homology searches, we provide evidence for 20 neuropeptide precursors together with four prepropeptide processing enzymes as well as several 5-HT signalling components to be represented in the Moniezia transcriptome.
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Affiliation(s)
- Gunnar R Mair
- Biomedical Sciences, Iowa State University, 1800 Christensen Drive, 2008 Vet Med, Ames, IA, 50011-1134, USA.
| | - David W Halton
- School of Biological Sciences, Queen's University of Belfast, Belfast, BT9 5DL, UK
| | - Aaron G Maule
- School of Biological Sciences, Queen's University of Belfast, Belfast, BT9 5DL, UK
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Ded L, Dostalova P, Zatecka E, Dorosh A, Komrskova K, Peknicova J. Fluorescent analysis of boar sperm capacitation process in vitro. Reprod Biol Endocrinol 2019; 17:109. [PMID: 31856844 PMCID: PMC6923987 DOI: 10.1186/s12958-019-0554-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Accepted: 12/06/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Capacitation involves physiological changes that spermatozoa must undergo in the female reproductive tract or in vitro to obtain the ability to bind, penetrate and fertilize the egg. Up to date, several methods have been developed to characterize this complex biological process. The goal of the presented study is to mutually compare several fluorescent techniques, check their ability to detect changes in molecular processes during the capacitation progress and determine their ability to predict the percentage of acrosome reacted (AR) sperm after the exposure to solubilized zona pellucida (ZP). The capacitation process was analyzed using four fluorescent techniques: 1. chlortetracycline (CTC) staining, 2. anti-acrosin antibody (ACR.2) assay, 3. anti-phosphotyrosine (pY) antibody assay, 4. fluorescein isothiocyanate-conjugated phalloidin (FITC-phall) assay. All these methods were tested using fluorescent microscopy and flow cytometry. RESULTS All selected methods are capable to detect the capacitation progress of boar sperm in vitro, but there are significant differences in their outcome when using fluorescent microscopy or flow cytometry experimental arrangements and subsequent statistical analysis (KW-ANOVA). Also, the ability to predict the absolute numbers of sperm which will undergo ZP-induced AR differ significantly (CTC and ACR.2 gave the best predictions). CONCLUSIONS Our study compared four largely used methods used to characterize capacitation process, highlighted their differences and showed that all are able to detect capacitation progress, CTC and ACR.2 are furthermore able to accurately predict the percentage of AR sperm after ZP-induced AR.
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Affiliation(s)
- Lukas Ded
- Laboratory of Reproductive Biology, Institute of Biotechnology, Czech Academy of Sciences, BIOCEV, Vestec, Czech Republic.
| | - Pavla Dostalova
- Laboratory of Reproductive Biology, Institute of Biotechnology, Czech Academy of Sciences, BIOCEV, Vestec, Czech Republic
| | - Eva Zatecka
- Laboratory of Reproductive Biology, Institute of Biotechnology, Czech Academy of Sciences, BIOCEV, Vestec, Czech Republic
| | - Andrej Dorosh
- Laboratory of Reproductive Biology, Institute of Biotechnology, Czech Academy of Sciences, BIOCEV, Vestec, Czech Republic
| | - Katerina Komrskova
- Laboratory of Reproductive Biology, Institute of Biotechnology, Czech Academy of Sciences, BIOCEV, Vestec, Czech Republic
- Department of Zoology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Jana Peknicova
- Laboratory of Reproductive Biology, Institute of Biotechnology, Czech Academy of Sciences, BIOCEV, Vestec, Czech Republic
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Gorrieri O, Fini M, Kyriakidou K, Zizzi A, Mattioli-Belmonte M, Castaldo P, De Cristofaro A, Natali D, Pugnaloni A, Biagini G. In Vitro Evaluation of Bio-Functional Performances of Ghimas Titanium Implants. Int J Artif Organs 2018; 29:1012-20. [PMID: 17211823 DOI: 10.1177/039139880602901012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Titanium is the most widely used material for dental implants. The natural formation, in presence of oxygen, of different oxide films (passivation films) is correlated to titanium implant biocompatibility, resistance to corrosion and is responsible for implant bacteriostatic action. Surface roughness is another surface property of Ti-implants that, affecting implant-to-bone contact, improves integration. In the present study data concerning composition, surface roughness and biocompatibility of Ghimas implants and mini-implants undergoing sandblasting with Calcium Magnesium Carbonate (CaMg(CO3)2) are reported. AFM, SEM/EDX, XRD analyses and morphofunctional tests (MTT and ALP) were performed. Cell actin cytoskeletal modification (fluorescence phalloidin staining) was also observed with confocal laser microscopy (CLSM). Data related to surface geometry and chemical properties, associated with evidence of high purity of all the tested materials (XRD and EDX), highlighted the elevated biocompatibility of tested implants and mini-implants. CLSM investigation confirmed osteoblast features of an active cell behavior able to fit cell to chemico-mechanical stimuli present at the bone/implant interface and suggests an effective implant/alveolar bone integration in vivo.
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Affiliation(s)
- O Gorrieri
- Department of Molecular Pathology and Innovative Therapies-Histology, Marche Polytechnic University, Ancona, Italy
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Materna SC, Swartz SZ, Smith J. Notch and Nodal control forkhead factor expression in the specification of multipotent progenitors in sea urchin. Development 2013; 140:1796-806. [PMID: 23533178 PMCID: PMC3621494 DOI: 10.1242/dev.091157] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/18/2013] [Indexed: 01/23/2023]
Abstract
Indirect development, in which embryogenesis gives rise to a larval form, requires that some cells retain developmental potency until they contribute to the different tissues in the adult, including the germ line, in a later, post-embryonic phase. In sea urchins, the coelomic pouches are the major contributor to the adult, but how coelomic pouch cells (CPCs) are specified during embryogenesis is unknown. Here we identify the key signaling inputs into the CPC specification network and show that the forkhead factor foxY is the first transcription factor specifically expressed in CPC progenitors. Through dissection of its cis-regulatory apparatus we determine that the foxY expression pattern is the result of two signaling inputs: first, Delta/Notch signaling activates foxY in CPC progenitors; second, Nodal signaling restricts its expression to the left side, where the adult rudiment will form, through direct repression by the Nodal target pitx2. A third signal, Hedgehog, is required for coelomic pouch morphogenesis and institution of laterality, but does not directly affect foxY transcription. Knockdown of foxY results in a failure to form coelomic pouches and disrupts the expression of virtually all transcription factors known to be expressed in this cell type. Our experiments place foxY at the top of the regulatory hierarchy underlying the specification of a cell type that maintains developmental potency.
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Affiliation(s)
- Stefan C. Materna
- California Institute of Technology, Division of Biology, m/c 156-29, Pasadena, CA 91125, USA
| | - S. Zachary Swartz
- Brown University, Department of Molecular Biology, Cell Biology and Biochemistry, 185 Meeting Street, Providence, RI 02912, USA
| | - Joel Smith
- California Institute of Technology, Division of Biology, m/c 156-29, Pasadena, CA 91125, USA
- Brown University, Department of Molecular Biology, Cell Biology and Biochemistry, 185 Meeting Street, Providence, RI 02912, USA
- Marine Biological Laboratory, 7 MBL Street, Woods Hole, MA 02543, USA
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Korohoda W, Grys M, Madeja Z. Reversible and irreversible electroporation of cell suspensions flowing through a localized DC electric field. Cell Mol Biol Lett 2013; 18:102-19. [PMID: 23271434 PMCID: PMC6275693 DOI: 10.2478/s11658-012-0042-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2012] [Accepted: 12/17/2012] [Indexed: 11/20/2022] Open
Abstract
Experiments on reversible and irreversible cell electroporation were carried out with an experimental setup based on a standard apparatus for horizontal electrophoresis, a syringe pump with regulated cell suspension flow velocity and a dcEF power supply. Cells in suspension flowing through an orifice in a barrier inserted into the electrophoresis apparatus were exposed to defined localized dcEFs in the range of 0-1000 V/cm for a selected duration in the range 10-1000 ms. This method permitted the determination of the viability of irreversibly electroperforated cells. It also showed that the uptake by reversibly electroperforated cells of fluorescent dyes (calcein, carboxyfluorescein, Alexa Fluor 488 Phalloidin), which otherwise do not penetrate cell membranes, was dependent upon the dcEF strength and duration in any given single electrical field exposure. The method yields reproducible results, makes it easy to load large volumes of cell suspensions with membrane non-penetrating substances, and permits the elimination of irreversibly electroporated cells of diameter greater than desired. The results concur with and elaborate on those in earlier reports on cell electroporation in commercially available electroporators. They proved once more that the observed cell perforation does not depend upon the thermal effects of the electric current upon cells. In addition, the method eliminates many of the limitations of commercial electroporators and disposable electroporation chambers. It permits the optimization of conditions in which reversible and irreversible electroporation are separated. Over 90% of reversibly electroporated cells remain viable after one short (less than 400 ms) exposure to the localized dcEF. Experiments were conducted with the AT-2 cancer prostate cell line, human skin fibroblasts and human red blood cells, but they could be run with suspensions of any cell type. It is postulated that the described method could be useful for many purposes in biotechnology and biomedicine and could help optimize conditions for in vivo use of both reversible and irreversible electroporation.
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Affiliation(s)
- Włodzimierz Korohoda
- Department of Cell Biology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Cracow, Poland
| | - Maciej Grys
- Department of Cell Biology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Cracow, Poland
| | - Zbigniew Madeja
- Department of Cell Biology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Cracow, Poland
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12
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Damann N, Owsianik G, Li S, Poll C, Nilius B. The calcium-conducting ion channel transient receptor potential canonical 6 is involved in macrophage inflammatory protein-2-induced migration of mouse neutrophils. Acta Physiol (Oxf) 2009; 195:3-11. [PMID: 18983454 DOI: 10.1111/j.1748-1716.2008.01918.x] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
AIM The role of the calcium-conducting ion channel transient receptor potential canonical 6 (TRPC6) in macrophage inflammatory protein-2 (MIP-2) induced migration of mouse neutrophils was investigated. METHODS Neutrophil granulocytes isolated from murine bone marrow of wild-type (TRPC6+/+) and TRPC6 knockout (TRPC6)/)) mice were tested for the presence of TRPC6 channel expression using quantitative real-time polymerase chain reactions and immunocytochemistry. The effect of different stimuli (e.g. MIP-2, 1-oleoyl-2-acetyl-sn-glycerol, formyl-methionyl-leucyl-phenylalanin) on migration of isolated neutrophils was tested by two-dimensional (2D) migration assays, phalloidin staining and intracellular calcium imaging. RESULTS We found that neutrophil granulocytes express TRPC6 channels. MIP-2 induced fast cell migration of isolated neutrophils in a 2D celltracking system. Strikingly, MIP-2 was less potent in neutrophils derived from TRPC6)/) mice. These cells showed less phalloidin-coupled fluorescence and the pattern of cytosolic calcium transients was altered. CONCLUSIONS We describe in this paper for the first time a role for transient receptor potential (TRP) channels in migration of native lymphocytes as a new paradigm for the universal functional role of TRPs. Our data give strong evidence that TRPC6 operates downstream to CXC-type Gq-protein-coupled chemokine receptors upon stimulation with MIP-2 and is crucial for the arrangement of filamentous actin in migrating neutrophils. This is a novel cell function of TRP channel beyond their well-recognized role as universal cell sensors.
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Affiliation(s)
- N Damann
- Department of Molecular Cell Biology, Laboratory of Ion Channel Research, KU Leuven, Leuven, Belgium
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13
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Bogoliubova NA, Bogoliubova IO. [Actin localization in the nuclei of two-cell mouse embryos]. Tsitologiia 2009; 51:663-669. [PMID: 19799350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
In this study, preimplantation mouse embryos were used as a new model for investigation of actin distribution in the nuclei and identification of functional forms of intranuclear actin. Combination of direct detection of actin by fluorescent-conjugated falloidin and DNase I with the method of indirect immunofluorescence was applied as an integrated approach to study localization of actin in the nuclei of two-cell mouse embryos. Monomeric actin and two oligomeric forms of actin were detected in the nuclei, and each of these forms demonstrated its own pattern of distribution. Oligomeric actin recognized by antibodies to C-terminal domain of actin was associated with condensed chromatin as well as with metaphase chromosomes and chromatin of second polar body. Monomeric actin and another oligomeric form recognized by antibodies to N-terminal domain were revealed in the area of dispersed chromatin localization.
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Mitsuyama F, Futatsugi Y, Okuya M, Karagiozov K, Kato Y, Kanno T, Sano H, Koide T, Sawai T. Microinjected F-actin into dividing newt eggs moves toward the next cleavage furrow together with Ca2+ stores with inositol 1,4,5-trisphosphate receptor in a microtubule- and microtubule motor-dependent manner. Ital J Anat Embryol 2008; 113:143-151. [PMID: 19205586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
It has been reported that F-actin is transported to the presumptive cleavage furrow along the cortex during anaphase-cytokinesis, an event termed cortical actin flow in animal cultured cells. The motor source has remained unknown. We reported that Ca2+ stores with IP3 receptor (IP3R) was re-distributed from the polar cortex during metaphase to the presumptive cleavage furrow just before the onset of furrowing, and that Ca2+ stores with IP3R microinjected into dividing newt eggs moved toward the presumptive cleavage furrow during anaphase-cytokinesis in a microtubule-dependent manner, and that Ca2+ store-enriched microsome fractions induced the cleavage furrow as the putative cleavage stimulus. Because the distribution of F-actin and Ca2+ stores with IP3R during metaphase to cytokinesis is similar, we considered that this cortical actin flow may be powered by transportation of Ca2+ stores with IP3R. Purified F-actin labeled with phalloidin-rhodamine was microinjected into the dividing newt eggs and the eggs observed under a confocal microscope. We found that the microinjected F-actin moved linearly toward the next cleavage furrow and that this movement was blocked by nocodazole, microtubule-depolarizing agent and AMP-PNP, a blocking agent of microtubule motors. Co-microinjected rhodamine-labeled F-actin and sacro/endoplasmic reticulum Ca2+-ATPase (SERCA)-GFP-labeled Ca2+ stores with IP3R co-moved and co-accumulated to the next cleavage furrow. These results strongly suggest that Ca2+ stores with IP3R, which is transferred by microtubule-based motility as cleavage stimulus, act as an F-actin translocator.
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Affiliation(s)
- Fuyuki Mitsuyama
- Department of Neurosurgery, Fujita Health University, Toyoake, Aichi, Japan.
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15
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Abstract
Laminin 5/laminin 332 (LN332) is an adhesion substrate for epithelial cells. After secretion of LN332, a regulated cleavage occurs at the carboxy-terminus of its alpha3 subunit, which releases a tandem of two globular modules named LG4/5. We show that the presence of the LG4/5 domain in precursor LN332 decreases its integrin-mediated cell adhesion properties in comparison with mature LN332. Whereas cell adhesion to the recombinant LG4/5 fragment relies solely on the heparan sulfate proteoglycan (HSPG) receptor syndecan-1, we reveal that both syndecan-1 and the alpha3beta1 integrin bind to precursor LN332. We further demonstrate that syndecan-1 mediated cell adhesion to the LG4/5 fragment and pre-LN332 allows the formation of fascin-containing protrusions, depending on the GTPases Rac and Cdc42 activation. Reducing syndecan-1 expression in normal keratinocytes prevents cell protrusions on pre-LN332 with subsequent failure of the peripheral localization of the alpha3beta1 integrin. We finally show that cell migration on pre-LN332 requires syndecan-1. Therefore, the LG4/5 domain in precursor LN332 appears to trigger intracellular signaling events, which participate in keratinocyte motility.
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Affiliation(s)
- Sophie Bachy
- IFR128 BioSciences Lyon-Gerland, Institut de Biologie et Chimie des Protéines, UMR 5086, CNRS, University Lyon1, 7 passage du Vercors, Lyon, France
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16
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Alvarez B, Stroeken PJM, Edel MJ, Roos E. Integrin Cytoplasmic domain-Associated Protein-1 (ICAP-1) promotes migration of myoblasts and affects focal adhesions. J Cell Physiol 2007; 214:474-82. [PMID: 17654484 DOI: 10.1002/jcp.21215] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Integrin Cytoplasmic domain-Associated Protein-1 (ICAP-1) binds specifically to the beta1 integrin subunit cytoplasmic domain. We observed that RNAi-induced knockdown of ICAP-1 reduced migration of C2C12 myoblasts on the beta1 integrin ligand laminin and that overexpression of ICAP-1 increased this migration. In contrast, migration on the beta3 integrin ligand vitronectin was not affected. ICAP-1 knockdown also greatly diminished migration of microvascular endothelial cells on collagen. The number of central focal adhesions in C2C12 cells on laminin was reduced by ICAP-1 knockdown and increased by ICAP-1 overexpression. Previously, we demonstrated that ICAP-1 binds to the ROCK-I kinase and translocates ROCK-I to the plasma membrane. We show here that the ROCK kinase inhibitor Y27362 reduces migration on laminin and causes a loss of central focal adhesions, similarly as ICAP-1 knockdown. ICAP-1 and ROCK were co-immune-precipitated from C2C12 cells, and in cells that overexpressed ICAP-1, YFP-ROCK was translocated to membrane ruffles. These results indicate that ICAP-1 regulates beta1 integrin-dependent cell migration by affecting the pattern of focal adhesion formation. This is likely due to ICAP-1-induced translocation of ROCK to beta1 integrin attachment sites.
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Affiliation(s)
- Belén Alvarez
- Division of Cell Biology, The Netherlands Cancer Institute, Amsterdam, The Netherlands
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17
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Watanabe K, Bianco C, Strizzi L, Hamada S, Mancino M, Bailly V, Mo W, Wen D, Miatkowski K, Gonzales M, Sanicola M, Seno M, Salomon DS. Growth factor induction of Cripto-1 shedding by glycosylphosphatidylinositol-phospholipase D and enhancement of endothelial cell migration. J Biol Chem 2007; 282:31643-55. [PMID: 17720976 DOI: 10.1074/jbc.m702713200] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cripto-1 (CR-1) is a glycosylphosphatidylinositol (GPI)-anchored membrane glycoprotein that has been shown to play an important role in embryogenesis and cellular transformation. CR-1 is reported to function as a membrane-bound co-receptor and as a soluble ligand. Although a number of studies implicate the role of CR-1 as a soluble ligand in tumor progression, it is unclear how transition from the membrane-bound to the soluble form is physiologically regulated and whether differences in biological activity exist between these forms. Here, we demonstrate that CR-1 protein is secreted from tumor cells into the conditioned medium after treatment with serum, epidermal growth factor, or lysophosphatidic acid, and this soluble form of CR-1 exhibits the ability to promote endothelial cell migration as a paracrine chemoattractant. On the other hand, membrane-bound CR-1 can stimulate endothelial cell sprouting through direct cell-cell interaction. Shedding of CR-1 occurs at the GPI-anchorage site by the activity of GPI-phospholipase D (GPI-PLD), because CR-1 shedding was suppressed by siRNA knockdown of GPI-PLD and enhanced by overexpression of GPI-PLD. These findings describe a novel molecular mechanism of CR-1 shedding, which may contribute to endothelial cell migration and possibly tumor angiogenesis.
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Affiliation(s)
- Kazuhide Watanabe
- Tumor Growth Factor Section, Mammary Biology & Tumorigenesis Laboratory, Center for Cancer Research, NCI, National Institutes of Health, Bethesda, Maryland 20892, USA
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18
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Gerbal-Chaloin S, Gondeau C, Aldrian-Herrada G, Heitz F, Gauthier-Rouvière C, Divita G. First step of the cell-penetrating peptide mechanism involves Rac1 GTPase-dependent actin-network remodelling. Biol Cell 2007; 99:223-38. [PMID: 17233629 DOI: 10.1042/bc20060123] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
BACKGROUND INFORMATION Application of CPPs (cell-penetrating peptides) constitutes a promising strategy for the intracellular delivery of therapeutic molecules. The non-covalent approach based on the amphipathic peptide MPG has been successfully used to improve the delivery of biologically active macromolecules, both in cellulo and in vivo, through a mechanism independent of the endosomal pathway and mediated by the membrane potential. RESULTS In the present study, we have investigated the first step of the cellular uptake mechanism of MPG and shown that both MPG and MPG-cargo complexes interact with the extracellular matrix through the negatively charged heparan sulfate proteoglycans. We demonstrated that initiation of cellular uptake constitutes a highly dynamic mechanism where the binding of MPG or the MPG-cargo to the extracellular matrix is rapidly followed by a remodelling of the actin network associated with the activation of the GTPase Rac1. We suggest that MPG-induced clustering of the glycosaminoglycan platform constitutes the 'onset' of the cellular uptake mechanism, thereby increasing membrane dynamics and membrane fusion processes. This process favours cell entry of MPG or MPG-DNA complexes, which is further controlled by the ability of MPG to induce a local membrane destabilization. CONCLUSIONS Although CPPs are taken up through different pathways and mechanisms, the initial step involves electrostatic interactions with the glycosaminoglycan platform, and the dynamics of associated membrane microdomains can be generalized to most non-viral delivery systems.
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Affiliation(s)
- Sabine Gerbal-Chaloin
- Centre de Recherches de Biochimie Macromoléculaire, Molecular Biophysics and Therapeutics, FRE-2593 CNRS, 1919 Route de Mende, 34293 Montpellier, France
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19
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Sato M, Suzuki K, Ueki Y, Ohashi T. Microelastic mapping of living endothelial cells exposed to shear stress in relation to three-dimensional distribution of actin filaments. Acta Biomater 2007; 3:311-9. [PMID: 17055790 DOI: 10.1016/j.actbio.2006.07.009] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2006] [Revised: 07/13/2006] [Accepted: 07/31/2006] [Indexed: 11/27/2022]
Abstract
The surface topography and local elastic moduli of endothelial cells exposed to shear stress were measured using atomic force microscopy. Bovine aortic endothelial cells were exposed to shear stress of 2Pa for 6, 12 or 24h. In addition, a confocal laser-scanning microscope used in conjunction with the atomic force microscope was used to observe the actin filament structure of these endothelial cells to elucidate the relationship between mechanical properties and cytoskeletal structure. The elastic modulus, calculated using the Hertz model, was measured at 50x50 points at 1mum intervals within 40min. For endothelial cells sheared for 6h and 12h, the elastic modulus at the upstream region was found to be higher than that at the downstream region. For endothelial cells sheared for 24h, the elastic modulus at both the upstream and downstream regions increased. Fluorescent images showed thick, elongated actin filaments oriented in the direction of flow at the ventral surface of the cells. In the middle plane of the cells, actin filaments developed around the nucleus, while in the upper plane, short, thick actin filaments were observed but thick stress fibers were not present. The high elastic modulus came from the stress fibers. These results indicate that the higher elastic modulus observed in the upstream and downstream regions of sheared endothelial cells is mainly due to the development of stress fibers at the ventral surface and middle plane of the cell.
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Affiliation(s)
- Masaaki Sato
- Department of Bioengineering and Robotics, Graduate School of Engineering, Tohoku University, 6-6-01 Aramaki-Aoba, Aoba, Sendai 980-8579, Japan.
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20
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Abstract
Interaction between the microtubule system and actin cytoskeleton has emerged as a fundamental process required for spatial regulation of cell protrusion and retraction activities. In our current studies, analysis of digital fluorescence images revealed targeting of microtubules to filopodia in B16F1 melanoma cells and fibroblasts. We investigated the functional consequence of targeting on filopodia reorganization and examined mechanisms by which microtubules may be guided to, or interact with, filopodia. Live cell imaging studies show that targeting events in lamellipodia wings temporally correlated with filopodia turning toward the lamellipodium midline and with filopodia merging. Rapid uncoupling of targeting with nocodazole decreased filopodia merging events and increased filopodia density. Total internal reflection fluorescence microscopy identified microtubules near the ventral surface and upward movement of targeted filopodia. The role of adhesion sites and microtubule plus-end proteins in targeting was investigated. Correlation of adhesion sites with microtubule targeting to filopodia was not observed and depletion of microtubule plus-end proteins did not significantly alter targeting frequency. We propose that microtubules target filopodia, independent of focal adhesions and plus-end proteins, causing filopodia movement and microtubules regulate filopodia density in lamellipodia wings through filopodia merging events.
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Affiliation(s)
- Joseph M Schober
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA.
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21
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Dornetshuber R, Heffeter P, Kamyar MR, Peterbauer T, Berger W, Lemmens-Gruber R. Enniatin exerts p53-dependent cytostatic and p53-independent cytotoxic activities against human cancer cells. Chem Res Toxicol 2007; 20:465-73. [PMID: 17326668 DOI: 10.1021/tx600259t] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Worldwide, multiple Fusarium mycotoxins occur as contaminants of cereals with important impacts on human and animal health. The aim of this study was to investigate the effects of the widespread Fusarium secondary metabolite enniatin (ENN), a cyclic hexadepsipeptide, on human cell growth and survival. While short-term exposure (up to 8 h) to ENN at nanomolar concentrations slightly but significantly stimulated cell proliferation, it showed profound apoptosis-inducing effects especially against various human cancer cell types at low micromolar concentrations (already after 24 h of treatment). Several cellular changes indicative for programmed cell death such as cell shrinkage, chromatin condensation, DNA fragmentation, and apoptotic body formation were observed. Correspondingly, the cleavage of poly(ADP-ribosyl)polymerase and the activation of multiple caspases accompanied a distinct loss of mitochondrial membrane potential. To investigate the impact of apoptosis- and cell cycle-regulating proteins on ENN activity, HCT116 cells with homozygously disrupted p53, p21, or bax genes were analyzed. In vitality assays, no significant influences of these proteins on the anticancer activity of ENN were detectable. In contrast, 3H-thymidine incorporation revealed a significantly more efficient block of DNA synthesis in p53 wild-type as compared to knock-out cells. Accordingly, fluorescence-activated cell sorting analysis demonstrated a stronger ENN-induced cell cycle arrest in the G0/G1 phase. Profound ENN-mediated induction of p53 and the p53-downstream cell cycle inhibitor p21 were detectable in p53 wild-type cells by Western blotting. P53-independent p21 induction was also detectable at higher ENN concentrations in p53 (-/-) cells. In contrast, bax activation by ENN was independent of the cellular p53 status. In summary, our results suggest that short-term exposure to very low ENN concentrations, for example, via food intake, might have tumor-promoting functions based on growth stimulation. In contrast, elevated ENN concentrations exert profound p53-dependent cytostatic and p53-independent cytotoxic activities especially against human cancer cells, suggesting a potential quality of ENN as an anticancer drug.
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Affiliation(s)
- Rita Dornetshuber
- Department of Pharmacology and Toxicology, University of Vienna, Althanstrasse 14, Vienna, Austria
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22
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Sigal YJ, Quintero OA, Cheney RE, Morris AJ. Cdc42 and ARP2/3-independent regulation of filopodia by an integral membrane lipid-phosphatase-related protein. J Cell Sci 2007; 120:340-52. [PMID: 17200142 DOI: 10.1242/jcs.03335] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Filopodia are dynamic cell surface protrusions that are required for proper cellular development and function. We report that the integral membrane protein lipid-phosphatase-related protein 1 (LPR1) localizes to and promotes the formation of actin-rich, dynamic filopodia, both along the cell periphery and the dorsal cell surface. Regulation of filopodia by LPR1 was not mediated by cdc42 or Rif, and is independent of the Arp2/3 complex. We found that LPR1 can induce filopodia formation in the absence of the Ena/Vasp family of proteins, suggesting that these molecules are not essential for the development of the protrusions. Mutagenesis experiments identified residues and regions of LPR1 that are important for the induction of filopodia. RNA interference experiments in an ovarian epithelial cancer cell line demonstrated a role for LPR1 in the maintenance of filopodia-like membrane protrusions. These observations, and our finding that LPR1 is a not an active lipid phosphatase, suggest that LPR1 may be a novel integral membrane protein link between the actin core and the surrounding lipid layer of a nascent filopodium.
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Affiliation(s)
- Yury J Sigal
- Department of Cell and Developmental Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7090, USA
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23
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Mendoza-Naranjo A, Gonzalez-Billault C, Maccioni RB. Abeta1-42 stimulates actin polymerization in hippocampal neurons through Rac1 and Cdc42 Rho GTPases. J Cell Sci 2007; 120:279-88. [PMID: 17200137 DOI: 10.1242/jcs.03323] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
A number of psychiatric and neurodegenerative disorders, such as Alzheimer's disease, are characterized by abnormalities in the neuronal cytoskeleton. Here, we find that the enhancement in actin polymerization induced by fibrillar amyloid-beta peptide (Abeta) is associated with increased activity of Rac1/Cdc42 Rho GTPases. Rac1 upregulation involves the participation of Tiam1, a Rac guanine-nucleotide exchange factor, where Abeta exposure leads to Tiam1 activation by a Ca(2+)-dependent mechanism. These results point to Rho GTPases as one of the targets in Abeta-induced neurodegeneration in Alzheimer's disease pathology, with a role in mediating changes in the actin cytoskeletal dynamics.
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Affiliation(s)
- Ariadna Mendoza-Naranjo
- Laboratory of Cellular, Molecular Biology and Neuroscience, Department of Biology, Faculty of Sciences, Universidad de Chile, Las Palmeras 3425, Nunoa, Santiago, Chile.
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Abstract
Since the early days of cell volume regulation research, the role of actin cytoskeleton organization and rearrangement has attracted specific interest. Rapid modifications in actin dynamics and architecture have been described. They were shown to regulate cell volume changes, as well as regulatory volume decrease in a large variety of cell types, including hepatocytes, lymphocytes, fibroblasts, myocytes, and various tumor cells. Using microscopic and biochemical analyses, modifications of actin organization and polymerization dynamics were studied. This chapter summarizes the molecular approaches applied so far for the quantitative assessment of actin cytoskeleton dynamics in the various cell types. It demonstrates that rapid modifications of actin cytoskeleton dynamics regulated by specific signaling pathways play a functional role in cell volume regulation. It is concluded that studying actin polymerization dynamics and signaling represents a challenging tool for the understanding of osmosensing and osmosignaling regulation in cellular physiology.
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25
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Abstract
Ena/VASP proteins negatively regulate cell motility and contribute to repulsion from several guidance cues; however, there is currently no evidence for a role downstream of Eph receptors. Eph receptors mediate repulsion from ephrins at sites of intercellular contact during several developmental migrations. For example, the expression of ephrin-Bs in posterior halves of somites restricts neural crest cell migration to the anterior halves. Here we show that ephrin-B2 destabilises neural crest cell lamellipodia when presented in a substrate-bound or soluble form. Our timelapse studies show that repulsive events are associated with the rearward collapse and subsequent loss of lamellipodia as membrane ruffles. We hypothesise that Ena/VASP proteins contribute to repulsion from ephrins by destabilising cellular protrusions and show that Ena/VASP-deficient fibroblasts exhibit reduced repulsion from both ephrin-A and ephrin-B stripes compared to wild-type controls. Moreover, when EphB4 and ephrin-B2 were expressed in neighbouring Swiss 3T3 fibroblasts, VASP and Mena co-accumulated with activated Eph receptors at protrusions formed by EphB4-expressing cells. Sequestration of Ena/VASP proteins away from the periphery of these cells inhibited Eph receptor internalisation, a process that facilitates repulsion. Our results suggest that Ena/VASP proteins regulate ephrin-induced Eph receptor signalling events, possibly by destabilising lamellipodial protrusions.
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Affiliation(s)
- Iwan R Evans
- Department of Biochemistry, School of Medical Sciences, University of Bristol, University Walk, Bristol, BS8 1TD, UK
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26
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Lecaudey V, Ulloa E, Anselme I, Stedman A, Schneider-Maunoury S, Pujades C. Role of the hindbrain in patterning the otic vesicle: a study of the zebrafish vhnf1 mutant. Dev Biol 2006; 303:134-43. [PMID: 17137573 DOI: 10.1016/j.ydbio.2006.10.041] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2006] [Revised: 10/27/2006] [Accepted: 10/27/2006] [Indexed: 10/24/2022]
Abstract
The vertebrate inner ear develops from an ectodermal placode adjacent to rhombomeres 4 to 6 of the segmented hindbrain. The placode then transforms into a vesicle and becomes regionalised along its anteroposterior, dorsoventral and mediolateral axes. To investigate the role of hindbrain signals in instructing otic vesicle regionalisation, we analysed ear development in zebrafish mutants for vhnf1, a gene expressed in the caudal hindbrain during otic induction and regionalisation. We show that, in vhnf1 homozygous embryos, the patterning of the otic vesicle is affected along both the anteroposterior and dorsoventral axes. First, anterior gene expression domains are either expanded along the whole anteroposterior axis of the vesicle or duplicated in the posterior region. Second, the dorsal domain is severely reduced, and cell groups normally located ventrally are shifted dorsally, sometimes forming a single dorsal patch along the whole AP extent of the otic vesicle. Third, and probably as a consequence, the size and organization of the sensory and neurogenic epithelia are disturbed. These results demonstrate that, in zebrafish, signals from the hindbrain control the patterning of the otic vesicle, not only along the anteroposterior axis, but also, as in amniotes, along the dorsoventral axis. They suggest that, despite the evolution of inner ear structure and function, some of the mechanisms underlying the regionalisation of the otic vesicle in fish and amniotes have been conserved.
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Affiliation(s)
- Virginie Lecaudey
- Unité de Biologie du Développement, CNRS UMR 7622, Université Pierre et Marie Curie, Paris, France
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Ugawa S, Inagaki A, Yamamura H, Ueda T, Ishida Y, Kajita K, Shimizu H, Shimada S. Acid-sensing ion channel-1b in the stereocilia of mammalian cochlear hair cells. Neuroreport 2006; 17:1235-9. [PMID: 16951561 DOI: 10.1097/01.wnr.0000233093.67289.66] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
We investigated whether amiloride-blockable proton-gated cation channels ASIC1a (acid-sensing ion channel-1a) and ASIC1b are expressed in the stereocilia of mouse cochlear hair cells. In-situ hybridization studies showed that ASIC1b transcripts, but not ASIC1a transcripts, were expressed in the inner and outer hair cells. Fluorescent immunohistochemical and immunogold electron microscopic analyses revealed that the ASIC1b channels were located at the insertions of the stereocilia into the hair cells. Our findings provide a novel molecular key to the understanding of cochlear physiology and pathophysiology.
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Affiliation(s)
- Shinya Ugawa
- Department of Molecular Morphology, Graduate School of Medical Sciences, Nagoya City University, Nagoya, Aichi, Japan.
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Mi Z, Mirnics ZK, Schor NF. Bcl-2 overexpression disrupts the morphology of PC12 cells through reduced ERK activation. Brain Res 2006; 1112:46-55. [PMID: 16914120 DOI: 10.1016/j.brainres.2006.07.017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2005] [Revised: 05/19/2006] [Accepted: 07/05/2006] [Indexed: 12/22/2022]
Abstract
Bcl-2 has been hypothesized to regulate many cellular functions in addition to its well-characterized role in the prevention of programmed cell death. To understand the role of Bcl-2 in regulating cell morphology and to explore the mechanism of this effect, we examined the effects of Bcl-2 overexpression on the morphology of PC12 cells in culture. We demonstrate that the overexpression of Bcl-2 in PC12 cells results in altered cell morphology and reduced actin expression. Analysis of extracellular signal-regulated kinase (ERK) 1/2 phosphorylation reveals that the morphological changes seen after bcl-2 transfection are associated with reduced ERK activation. Treatment of control (mock-transfected) PC12 cells with the mitogen-activated ERK-activating kinase (MEK) inhibitor PD98059 converts their flat, process-bearing morphology into the rounded, process-free morphology of bcl-2-transfected cells, further confirming the association of ERK activation with altered cell shape. In conclusion, the present study describes a novel function of Bcl-2 in regulating cell shape through reduced ERK activation.
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Affiliation(s)
- Zhiping Mi
- Pediatric Center for Neuroscience, Children's Hospital of Pittsburgh of UPMC, Pittsburgh, PA 15213, USA
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29
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Wood JE, Schneider H, Rudd CE. TcR and TcR-CD28 engagement of protein kinase B (PKB/AKT) and glycogen synthase kinase-3 (GSK-3) operates independently of guanine nucleotide exchange factor VAV-1. J Biol Chem 2006; 281:32385-94. [PMID: 16905544 DOI: 10.1074/jbc.m604878200] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
TcRzeta/CD3 and TcRzeta/CD3-CD28 signaling requires the guanine nucleotide exchange factor (GEF) Vav-1 as well as the activation of phosphatidylinositol 3-kinase, protein kinase B (PKB/AKT), and its inactivation of glycogen synthase kinase-3 (GSK-3). Whether these two pathways are connected or operate independently of each other in T-cells has been unclear. Here, we report that anti-CD3 and anti-CD3/CD28 can induce PKB and GSK-3alpha phosphorylation in the Vav-1(-/-) Jurkat cell line J. Vav.1 and in primary CD4-positive Vav-1(-/-) T-cells. Reduced GSK-3alpha phosphorylation was observed in Vav-1,2,3(-/-) T-cells together with a complete loss of FOXO1 phosphorylation. Furthermore, PKB and GSK-3 phosphorylation was unperturbed in the presence of GEF-inactive Vav-1 that inhibited interleukin-2 gene activation and a form of Src homology 2 domain-containing lymphocytic protein of 76-kDa (SLP-76) that is defective in binding to Vav-1. The pathway also was intact under conditions of c-Jun N-terminal kinase (JNK) inhibition and disruption of the actin cytoskeleton by cytochalasin D. Both events are down-stream targets of Vav-1. Overall, our findings indicate that the TcR and TcR-CD28 driven PKB-GSK-3 pathway can operate independently of Vav-1 in T-cells.
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Affiliation(s)
- Joanne E Wood
- Molecular Immunology Section, Department of Immunology, Imperial College London, London W12 ONN, United Kingdom
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Li HB, Ge YK, Zhang L, Zheng XX. Astragaloside IV improved barrier dysfunction induced by acute high glucose in human umbilical vein endothelial cells. Life Sci 2006; 79:1186-93. [PMID: 16650877 DOI: 10.1016/j.lfs.2006.03.041] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2005] [Revised: 03/08/2006] [Accepted: 03/16/2006] [Indexed: 01/30/2023]
Abstract
The purpose of the present study was to examine the effects of astragaloside IV, a saponin isolated from Astragalus membranaceus (Fisch) Bge, on the impairment of barrier function induced by acute high glucose in cultured human vein endothelial cells. High glucose (27.8 mM) induced a decrease in transendothelial electrical impedance and an increase in cell monolayer permeability in human umbilical vein endothelial cells. Endothelial barrier dysfunction stimulated by high glucose was accompanied by translocation and activation of protein kinase C (PKC), the redistribution of F-actin and formation of intercellular gaps, suggesting that increases in PKC activity and rearrangement of F-actin could be associated with endothelial barrier dysfunction induced by acute high glucose. Application of astragaloside IV inhibited high glucose-induced endothelial barrier dysfunction in a dose-dependent manner, which is compatible with inhibition of PKC translocation and improvement of F-actin rearrangements. Western blot analysis revealed that high glucose-induced PKC alpha and beta2 overexpression in the membrane fraction were significantly reduced by astragaloside IV. These findings indicate that astragaloside IV protected endothelial cells from high glucose-induced barrier impairment by inhibiting PKC activation, as well as improving cytoskeleton remodeling.
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Affiliation(s)
- Han-Bing Li
- Department of Biomedical Engineering, Zhejiang University (Yuquan Campus), Hangzhou 310027, PR China
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31
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Taura A, Kojima K, Ito J, Ohmori H. Recovery of hair cell function after damage induced by gentamicin in organ culture of rat vestibular maculae. Brain Res 2006; 1098:33-48. [PMID: 16764839 DOI: 10.1016/j.brainres.2006.04.090] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2005] [Revised: 04/13/2006] [Accepted: 04/17/2006] [Indexed: 11/25/2022]
Abstract
Here, we report the functional and morphological evidence of hair cell recovery after damages induced by gentamicin (GM) in cultured explants of rat vestibular maculae. We evaluated mechano-electrical transduction (MET) function in hair cells, by measuring Ca(2+) responses in the explants with fura-2 when hair bundles were stimulated. After the MET testing, hair bundles were observed in high resolution by scanning electron microscopy, or by fluorescence microscopy after staining with phalloidin-FITC (fluorescent isothiocyanate). In the control culture, the number of hair bundles on the explants gradually decreased, and the percentage of explants showing Ca(2+) responses decreased and disappeared after 17 days in culture. Following GM (1-2 mM) treatment, most of the hair bundles were eliminated initially, but the hair bundles gradually increased in number during culture. Short hair bundle-like structures emerged in the areas where hair bundles had been completely lost. Consistent with the morphological observations, Ca(2+) responses disappeared after GM treatment, and they gradually recovered to a peak 13-17 days after treatment and were even induced at 17 days or more in culture. Furthermore, cells accumulated FM1-43, a dye permeable through the MET channel, when Ca(2+) responses recovered after GM treatment. Application of steroid hormone increased the percentage of explants showing MET activity, and enhanced the recovery of MET after GM treatment. We investigated Ki-67 immunoreactivity to detect cell proliferation and TUNEL staining to detect apoptotic cell death. Ki-67 immunoreactivity was negative after GM treatment, however TUNEL staining was positive and the positivity was GM dose dependent. Therefore, this functional recovery of transduction activity was not owing to the proliferation of hair cells but was likely the self-repair of the hair bundle.
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Affiliation(s)
- Akiko Taura
- Department of Otolaryngology-Head and Neck Surgery, Kyoto University, Japan
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32
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Abstract
The establishment of polarity in Drosophila requires the correct specification of the oocyte in early stages of oogenesis, its positioning at the posterior of the egg chamber, and signalling events between the oocyte and the adjacent posterior follicle cells. As a consequence, the anterior-posterior and the dorsal-ventral axes are fixed. The posterior localisation of the oocyte depends on cadherin-mediated adhesion between the oocyte and the follicle cells. Here we show that dicephalic mutants affect the posterior positioning of the oocyte without interfering with oocyte specification in the germarium. Unlike other mutants that also affect the posterior placement of the oocyte, dicephalic mutants affect neither gurken expression nor karyosome formation during meiosis. By analysing in detail the mutant phenotypes of dicephalic, we find that cyst formation in mutant germaria is defective and that it shares some similarities with cysts that lack DE-cadherin in the germline cells. We propose a model in which dicephalic is involved in the proper adhesion between the oocyte and the somatic follicle cells.
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Affiliation(s)
- Ruth McCaffrey
- MRC Laboratory of Molecular Biology, Cambridge, United Kingdom
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33
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Abstract
Chromosome congression and segregation have been widely known to be coordinated by the function of the dynamic spindle microtubules. But recent work suggests that oocytes may employ a unique actin-dependent mechanism of chromosome delivery to the spindle.
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Affiliation(s)
- Rania S Rizk
- Medical Sciences, Indiana University, 915 E. 3rd St., Myers Hall 262, Bloomington, Indiana 47405, USA
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Abstract
Fertilization triggers a reorganization of oocyte cytoskeleton, and in sea urchins, there is a dramatic increase in cortical F-actin. However, the role that myosin II plays during fertilization remains largely unexplored. Myosin II is localized to the cortical cytoskeleton both before and after fertilization and to examine myosin II contractility in living cells, Lytechinus pictus eggs were observed by time-lapse microscopy. Upon sperm binding, a cell surface deflection traversed the egg that was followed by and dependent on the calcium wave. The calcium-dependence of surface contractility could be reproduced in unfertilized eggs, where mobilization of intracellular calcium in unfertilized eggs under compression resulted in a marked contractile response. Lastly, inhibition of myosin II delayed absorption of the fertilization cone, suggesting that myosin II not only responds to the same signals that activate eggs but also participates in the remodeling of the cortical actomyosin cytoskeleton during the first zygotic cell cycle.
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Affiliation(s)
- Christianna Stack
- Department of Biology, New Mexico State University, Las Cruces, NM 88003-8001, USA
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35
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Abstract
In neural crest formation, transcription factors, such as group E Sox and Snail1/Snail2 (Slug) regulate subsequent epithelial-mesenchymal transition (EMT) and migration. In particular, Sox9 has a strong effect on neural crest formation, EMT and differentiation of crest-derived cartilages in the cranium. It remains unclear, however, how Sox9 functions in these events, and how Sox9 activity is regulated. In this study, our gain-of-function and loss-of-function experiments reveal that Sox9 is essential for BMP signal-mediated induction of Snail2 and subsequent EMT in avian neural crest. We also show that Snail2 activates the Snail2 promoter, although Snail family proteins have been known as a repressor. Consistently, Sox9 directly activates the Snail2 promoter in synergy with, and through a direct binding to,Snail2. Finally, functions of these transcription factors in neural crest cells are enhanced by PKA signaling.
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Affiliation(s)
- Daisuke Sakai
- Center for Translational and Advanced Animal Research on Human Diseases, Division of Developmental Neuroscience, Graduate School of Medicine, Tohoku University, Sendai, Miyagi 980-8575, Japan
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36
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Abstract
Expression of connective tissue growth factor (CTGF) is sensitive to reorganization of the actin cytoskeleton, but also to alterations in cell morphology due to extracellular forces, for example, cyclic stretching or mechanical loading. Dynamic alterations of focal adhesion proteins were thus proposed to modulate CTGF induction. Immortalized human renal fibroblasts were cultured in or on top of preformed collagen-1 gels. Proteins were detected by immunofluorescence and quantified by Western blotting. Fibroblasts cultured in/on collagen gels resembled cells in vivo by their spindle-like morphology, absence of actin stress fibers, small punctiform focal contacts, and low levels of CTGF expression. Disassembly of microtubules by short-term treatment with colchicine induced cell rounding, cortical recruitment of patchy F-actin, reorganization of focal contacts into strong clusters, and upregulation of CTGF, all of which were dependent on RhoA-Rho-kinase signaling. Clustering of focal adhesion sites activated Src-family kinases and focal adhesion kinase (FAK). Interference with Src activity by PP2 had no effect on the morphological alterations but decreased tyrosine phosphorylation of focal adhesion proteins and almost completely prevented upregulation of CTGF. Furthermore, inhibition of phosphatidylinositol 3-kinase reduced CTGF expression. On the other hand, when the fibroblasts were cultured on a rigid matrix, that is collagen-coated plates, strong focal complexes prevented the dynamic alterations, and RhoA-mediated upregulation of CTGF expression was independent of Src-FAK signaling. Assembly of focal adhesion proteins regulates CTGF expression, providing a link between actin network, adhesion receptors, and CTGF-mediated functions such as synthesis of extracellular matrix proteins.
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Affiliation(s)
- A Graness
- Department of Nephrology, University of Erlangen-Nuremberg, Erlangen, Germany
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37
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Hammond KL, Whitfield TT. The developing lamprey ear closely resembles the zebrafish otic vesicle: otx1 expression can account for all major patterning differences. Development 2006; 133:1347-57. [PMID: 16510503 DOI: 10.1242/dev.02306] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The inner ear of adult agnathan vertebrates is relatively symmetric about the anteroposterior axis, with only two semicircular canals and a single sensory macula. This contrasts with the highly asymmetric gnathostome arrangement of three canals and several separate maculae. Symmetric ears can be obtained experimentally in gnathostomes in several ways, including by manipulation of zebrafish Hedgehog signalling, and it has been suggested that these phenotypes might represent an atavistic condition. We have found, however, that the symmetry of the adult lamprey inner ear is not reflected in its early development; the lamprey otic vesicle is highly asymmetric about the anteroposterior axis, both morphologically and molecularly, and bears a striking resemblance to the zebrafish otic vesicle. The single sensory macula originates as two foci of hair cells, and later shows regions of homology to the zebrafish utricular and saccular maculae. It is likely, therefore, that the last common ancestor of lampreys and gnathostomes already had well-defined otic anteroposterior asymmetries. Both lamprey and zebrafish otic vesicles express a target of Hedgehog signalling, patched, indicating that both are responsive to Hedgehog signalling. One significant distinction between agnathans and gnathostomes, however, is the acquisition of otic Otx1 expression in the gnathostome lineage. We show that Otx1 knockdown in zebrafish, as in Otx1(-/-) mice, gives rise to lamprey-like inner ears. The role of Otx1 in the gnathostome ear is therefore highly conserved; otic Otx1 expression is likely to account not only for the gain of a third semicircular canal and crista in gnathostomes, but also for the separation of the zones of the single macula into distinct regions.
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Affiliation(s)
- Katherine L Hammond
- Department of Biomedical Science, Centre for Developmental and Biomedical Genetics, University of Sheffield, Sheffield S10 2TN, UK
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38
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Meller K, Theiss C. Atomic force microscopy and confocal laser scanning microscopy on the cytoskeleton of permeabilised and embedded cells. Ultramicroscopy 2006; 106:320-5. [PMID: 16360280 DOI: 10.1016/j.ultramic.2005.10.003] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2005] [Revised: 10/07/2005] [Accepted: 10/19/2005] [Indexed: 11/23/2022]
Abstract
We describe a technical method of cell permeabilisation and embedding to study the organisation and distribution of intracellular proteins with aid of atomic force microscopy and confocal laser scanning microscopy in identical areas. While confocal laser scanning microscopy is useful for the identification of certain proteins subsequent labelling with markers or antibodies, atomic force microscopy allows the observation of macromolecular structures in fixed and living cells. To demonstrate the field of application of this preparatory technique, cells were permeabilised, fixed, and the actin cytoskeleton was stained with phalloidin-rhodamine. Confocal laser scanning microscopy was used to show the organisation of these microfilaments, e.g. geodesic dome structures. Thereafter, cells were embedded in Durcupan water-soluble resin, followed by UV-polymerisation of resin at 4 degrees C. This procedure allowed intracellular visualisation of the cell nucleus or cytoskeletal elements by atomic force microscopy, for instance to analyse the globular organisation of actin filaments. Therefore, this method offers a great potential to combine both microscopy techniques in order to understand and interpret intracellular protein relations, for example, the biochemical and morphological interaction of the cytoskeleton.
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Affiliation(s)
- Karl Meller
- Abteilung für Cytologie, Ruhr-University Bochum, Bochum, Germany
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39
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Kudryashov DS, Galkin VE, Orlova A, Phan M, Egelman EH, Reisler E. Cofilin cross-bridges adjacent actin protomers and replaces part of the longitudinal F-actin interface. J Mol Biol 2006; 358:785-97. [PMID: 16530787 DOI: 10.1016/j.jmb.2006.02.029] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2005] [Revised: 01/22/2006] [Accepted: 02/13/2006] [Indexed: 11/25/2022]
Abstract
ADF/cofilins are abundant actin binding proteins critical to the survival of eukaryotic cells. Most ADF/cofilins bind both G and F-actin, sever the filaments and accelerate their treadmilling. These effects are linked to rearrangements of interprotomer contacts, changes in the mean twist, and filament destabilization by ADF/cofilin. Paradoxically, it was reported that under certain in vitro and in vivo conditions cofilin may stabilize actin filaments and nucleate their formation. Here, we show that yeast cofilin and human muscle cofilin (cofilin-2) accelerate the nucleation and elongation of ADP-F-actin and stabilize such filaments. Moreover, cofilin rescues the polymerization of the assembly incompetent tethramethyl rhodamine (TMR)-actin and T203C/C374S yeast mutant actin. Filaments of cofilin-decorated TMR-actin and unlabeled actin are indistinguishable, as revealed by electron microscopy and three-dimensional reconstruction. Our data suggest that ADF/cofilins play an active role in establishing new interprotomer interfaces in F-actin that substitute for disrupted (as in TMR-actin and mutant actin) or weakened (as in ADP-actin) longitudinal contacts in filaments.
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Affiliation(s)
- D S Kudryashov
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095, USA.
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40
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Cougoule C, Hoshino S, Dart A, Lim J, Caron E. Dissociation of recruitment and activation of the small G-protein Rac during Fcgamma receptor-mediated phagocytosis. J Biol Chem 2006; 281:8756-64. [PMID: 16434390 DOI: 10.1074/jbc.m513731200] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Rho-family proteins play a central role in most actin-dependent processes, including the control and maintenance of cell shape, adhesion, motility, and phagocytosis. Activation of these GTP-binding proteins is tightly regulated spatially and temporally; however, very little is known of the mechanisms involved in their recruitment and activation in vivo. Because of its inducible, restricted signaling, phagocytosis offers an ideal physiological system to delineate the pathways linking surface receptors to actin remodeling via Rho GTPases. In this study, we investigated the involvement of early regulators of Fcgamma receptor signaling in Rac recruitment and activation. Using a combination of receptor mutagenesis, cellular, molecular, and pharmacological approaches, we show that Src family and Syk kinases control Rac and Vav function during phagocytosis. Importantly, both the immunoreceptor tyrosine-based activation motif within Fcgamma receptor cytoplasmic domain and Src kinase control the recruitment of Vav and Rac. However, Syk activity is dispensable for Vav and Rac recruitment. Moreover, we show that Rac and Cdc42 activities coordinate F-actin accumulation at nascent phagosomes. Our results provide new insights in the understanding of the spatiotemporal regulation of Rho-family GTPase function, and of Rac in particular, during phagocytosis. We believe they will contribute to a better understanding of more complex cellular processes, such as cell adhesion and migration.
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Affiliation(s)
- Céline Cougoule
- Centre for Molecular Microbiology and Infection, and Division of Cell and Molecular Cell biology, Faculty of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom
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41
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Abstract
The musculature of the cubomedusa Tripedalia cystophora was investigated using immunohistochemical staining with an anti-actin antibody and histochemical staining with fluorescent phalloidin. The subumbrella is lined with a sheet of circular, striated muscle that is interrupted at the perradii, and by the nerve ring. The sheet is continuous with circular, striated muscle of the velarium, which turns radially on each face of the four velarial frenula. Perradial strips of smooth muscle run radially from just above the level of the rhopalia into the manubrium and lips. The strips give off perpendicular offshoots that run a short distance in parallel with the circular swim muscle. Musculature of the tentacles and pedalia is longitudinal and limited to the oral side of the pedalia. The pedalial muscle connects with bundles of smooth muscle that runs circularly from the tentacle base well into the subumbrella. The arrangement of striated muscle in the frenula suggests that these structures may function in directional nozzle formation of the velarium during turning. In addition, the perpendicular branching of the radial strips and the circular extensions of pedalial muscle may function in hinge formation to aid bending of the pedalia and tentacles into the subumbrella during feeding and protective responses.
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Affiliation(s)
- Richard A Satterlie
- Center for Marine Science, University of North Carolina Wilmington, 5600 Marvin K. Moss Lane, Wilmington, North Carolina 28409, USA.
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42
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La Ragione RM, Patel S, Maddison B, Woodward MJ, Best A, Whitelam GC, Gough KC. Recombinant anti-EspA antibodies block Escherichia coli O157:H7-induced attaching and effacing lesions in vitro. Microbes Infect 2005; 8:426-33. [PMID: 16298154 DOI: 10.1016/j.micinf.2005.07.009] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2005] [Accepted: 07/13/2005] [Indexed: 12/28/2022]
Abstract
Intimin and EspA proteins are virulence factors expressed by attaching and effacing Escherichia coli (AEEC) such as enteropathogenic and enterohaemorrhagic E. coli. The EspA protein makes up a filament structure forming part of the type III secretion system (TTSS) that delivers effector proteins to the host epithelial cell. Bacterial surface displayed intimin interacts with translocated intimin receptor in the host cell membrane leading to intimate attachment of the bacterium and subsequent attaching and effacing lesions. Here, we have assessed the use of recombinant monoclonal antibodies against E. coli O157:H7 EspA and intimin for the disruption of AEEC interaction with the host cell. Anti-gamma intimin antibodies did not reduce either adhesion of E. coli O157:H7 to host cell mono-layers or subsequent host cell actin rearrangement. Anti-EspA antibodies similarly had no effect on bacterial adhesion however they had a marked effect upon E. coli O157:H7-induced host cell actin rearrangement, where both monoclonal and polyclonal antibodies completely blocked cytoskeletal changes within the host cell. Furthermore, these anti-EspA antibodies were shown to reduce actin rearrangement induced by some but not all other AEEC serotypes tested. Both polyclonal and monoclonal antibodies could be used to label E. coli O157 EspA filaments and these immunoreagents did not inhibit the formation of such filaments. This is the first report of monoclonal antibodies to EspA capable of disrupting the TTSS function of E. coli O157:H7.
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Affiliation(s)
- Roberto M La Ragione
- Veterinary Laboratories Agency, Department of Food and Environmental Safety, Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB, UK
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Ryan XP, Alldritt J, Svenningsson P, Allen PB, Wu GY, Nairn AC, Greengard P. The Rho-specific GEF Lfc interacts with neurabin and spinophilin to regulate dendritic spine morphology. Neuron 2005; 47:85-100. [PMID: 15996550 DOI: 10.1016/j.neuron.2005.05.013] [Citation(s) in RCA: 125] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2003] [Revised: 01/24/2004] [Accepted: 05/06/2005] [Indexed: 01/07/2023]
Abstract
Neurabin and spinophilin are homologous protein phosphatase 1 and actin binding proteins that regulate dendritic spine function. A yeast two-hybrid analysis using the coiled-coil domain of neurabin revealed an interaction with Lfc, a Rho GEF. Lfc was highly expressed in brain, where it interacted with either neurabin or spinophilin. In neurons, Lfc was largely found in the shaft of dendrites in association with microtubules but translocated to spines upon neuronal stimulation. Moreover, expression of Lfc resulted in reduction in spine length and size. Both the translocation and the effect on spine morphology depended on the coiled-coil domain of Lfc. Coexpression of neurabin or spinophilin with Lfc resulted in their clustering together with F-actin, a process that depended on Rho activity. Thus, interaction between Lfc and neurabin/spinophilin selectively regulates Rho-dependent organization of F-actin in spines and is a link between the microtubule and F-actin cytoskeletons in dendrites.
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Affiliation(s)
- Xiaozhou P Ryan
- Laboratory of Molecular and Cellular Neuroscience, Rockefeller University, 1230 York Avenue, New York, NY 10021, USA
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44
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Torreano PJ, Waterman-Storer CM, Cohan CS. The effects of collapsing factors on F-actin content and microtubule distribution of Helisoma growth cones. ACTA ACUST UNITED AC 2005; 60:166-79. [PMID: 15700278 DOI: 10.1002/cm.20051] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Growth cone collapsing factors induce growth cone collapse or repulsive growth cone turning by interacting with membrane receptors that induce alterations in the growth cone cytoskeleton. A common change induced by collapsing factors in the cytoskeleton of the peripheral domain, the thin lamellopodial area of growth cones, is a decline in the number of radially aligned F-actin bundles that form the core of filopodia. The present study examined whether ML-7, a myosin light chain kinase inhibitor, serotonin, a neurotransmitter and TPA, an activator of protein kinase C, which induce growth cone collapse of Helisoma growth cones, depolymerized or debundled F-actin. We report that these collapsing factors had different effects. ML-7 induced F-actin reorganization consistent with debundling whereas serotonin and TPA predominately depolymerized and possibly debundled F-actin. Additionally, these collapsing factors induced the formation of a dense actin-ring around the central domain, the thicker proximal area of growth cones [Zhou and Cohan, 2001: J. Cell Biol. 153:1071-1083]. The formation of the actin-ring occurred subsequent to the loss of actin bundles. The ML-7-induced actin-ring was found to inhibit microtubule extension into the P-domain. Thus, ML-7, serotonin, and TPA induce growth cone collapse associated with a decline in radially aligned F-actin bundles through at least two mechanisms involving debundling of actin filaments and/or actin depolymerization.
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Affiliation(s)
- Paul J Torreano
- Division of Anatomy and Cell Biology, University at Buffalo School of Medicine, Buffalo, NY 14214, USA
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Riparbelli MG, Inoue Y, Glover DM, Callaini G. parva germina, A gene involved in germ cell maintenance during male and female Drosophila gametogenesis. Dev Dyn 2005; 232:835-44. [PMID: 15704116 DOI: 10.1002/dvdy.20190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
We report the initial characterization of a gene, parva germina (pag), required for germ cell maintenance in both males and females. pag gonads contain a small number of germline stem cells at the onset of gametogenesis. In contrast, adult mutant gonads are either empty or have a very small number of germ cells that never develop in 16-cell cysts. Ovarioles and testes, therefore, are rudimentary, and the very few germ cells they contain are unable to differentiate into eggs or sperm. Germline stem cells are progressively depleted over time. The average number of germ cells, therefore, decreases in pag mutant ovarioles with the age of the mother, whereas the proportion of agametic germaria goes up. These observations suggest that the pag gene product is involved in germ cell maintenance in both male and female gametogenesis.
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Szczepanowska J, Zabłocki K, Duszyński J. Influence of a mitochondrial genetic defect on capacitative calcium entry and mitochondrial organization in the osteosarcoma cells. FEBS Lett 2005; 578:316-22. [PMID: 15589839 DOI: 10.1016/j.febslet.2004.11.022] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2004] [Revised: 11/03/2004] [Accepted: 11/09/2004] [Indexed: 10/26/2022]
Abstract
Effects of T8993G mutation in mitochondrial DNA (mtDNA), associated with neurogenical muscle weakness, ataxia and retinitis pigmentosa (NARP), on the cytoskeleton, mitochondrial network and calcium homeostasis in human osteosarcoma cells were investigated. In 98% NARP and rho(0) (lacking mtDNA) cells, the organization of the mitochondrial network and actin cytoskeleton was disturbed. Capacitative calcium entry (CCE) was practically independent of mitochondrial energy status in osteosarcoma cell lines. The significantly slower Ca(2+) influx rates observed in 98% NARP and rho(0), in comparison to parental cells, indicates that proper actin cytoskeletal organization is important for CCE in these cells.
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Affiliation(s)
- Joanna Szczepanowska
- Department of Cellular Biochemistry, Nencki Institute of Experimental Biology, Pasteura 3, 02 093 Warsaw, Poland.
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Abstract
Cells sense and respond to mechanical force. However, the mechanisms of transduction of extracellular matrix (ECM) forces to biochemical signals are not known. After removing the cell membrane and soluble proteins by Triton X-100 extraction, we found that the remaining complex (Triton cytoskeletons) activated Rap1 upon stretch. Rap1 guanine nucleotide exchange factor, C3G, was required for this activation; C3G as well as the adaptor protein, CrkII, in cell extract bound to Triton cytoskeletons in a stretch-dependent manner. CrkII binding, which was Cas dependent, correlated with stretch-dependent tyrosine phosphorylation of proteins in Triton cytoskeletons including Cas at the contacts with ECM. These in vitro findings were compatible with in vivo observations of stretch-enhanced phosphotyrosine signals, accumulation of CrkII at cell-ECM contacts, and CrkII-Cas colocalization. We suggest that mechanical force on Triton cytoskeletons activates local tyrosine phosphorylation, which provides docking sites for cytosolic proteins, and initiates signaling to activate Rap1.
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Affiliation(s)
- Masako Tamada
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA
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Osińska-Królicka I, Podsiadły H, Bukietyńska K, Zemanek-Zboch M, Nowak D, Suchoszek-Łukaniuk K, Malicka-Błaszkiewicz M. Vanadium(III) complexes with l-cysteine – stability, speciation and the effect on actin in hepatoma Morris 5123 cells. J Inorg Biochem 2004; 98:2087-98. [PMID: 15541498 DOI: 10.1016/j.jinorgbio.2004.09.013] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2004] [Revised: 09/09/2004] [Accepted: 09/18/2004] [Indexed: 11/30/2022]
Abstract
The complexation processes of vanadium(III) with L-cysteinate and s-methyl-L-cysteinate ligands have been studied in aqueous solutions in the pH range 2-7 by the pH-potentiometric, UV-Vis absorption and CD spectroscopy methods. The equilibria model of complex formation, evaluated by SUPERQUAD program, so as careful inspection of spectroscopic data have allowed to determine the speciation and the coordination mode of vanadium(III) ion in the major species present in aqueous solutions. Relatively stable ML2 species of vanadium(III)-L-cysteinate system exists in aqueous solutions above pH 5. It was deduced from spectral data that the coordination sphere of vanadium(III) ion in V(Cys)2 is completed by oxygen, nitrogen and sulfur atoms of two L-cysteinate ligands. Solution of vanadium(III) with L-cysteine (pH approximately 7, L/M=20) was administrated to the culture medium of hepatoma Morris 5123 growing cells. Cytotoxic effect of this solution towards tumor cells was observed. The viability of these cells depended on the complex concentration. It was reduced by 70% at 100 microM of the vanadium species concentration in the culture medium. The death of cancer cells seems to be induced on apoptotic route. The statistically significant increase of total actin level and filamentous to monomeric actin ratios (F/G) were found in the cytoplasm of cells exposed to the vanadium(III)-L-cysteine complex. It was accompanied by the rearrangement of actin cytoskeleton architecture. These factors are important for migration and metastasis formation of the cancer cells.
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Affiliation(s)
- I Osińska-Królicka
- Faculty of Chemistry, University of Wrocław, F. Joliot-Curie 14, 50-383 Wrocław, Poland
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Jurado C, Haserick JR, Lee J. Slipping or gripping? Fluorescent speckle microscopy in fish keratocytes reveals two different mechanisms for generating a retrograde flow of actin. Mol Biol Cell 2004; 16:507-18. [PMID: 15548591 PMCID: PMC545886 DOI: 10.1091/mbc.e04-10-0860] [Citation(s) in RCA: 176] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Fish keratocytes can generate rearward directed traction forces within front portions of the lamellipodium, suggesting that a retrograde flow of actin may also occur here but this was not detected by previous photoactivation experiments. To investigate the relationship between retrograde flow and traction force generation, we have transfected keratocytes with GFP-actin and used fluorescent speckle microscopy, to observe speckle flow. We detected a retrograde flow of actin within the leading lamellipodium that is inversely proportional to both protrusion rate and cell speed. To observe the effect of reducing contractility, we treated transfected cells with ML7, a potent inhibitor of myosin II. Surprisingly, ML7 treatment led to an increase in retrograde flow rate, together with a decrease in protrusion and cell speed, but only in rapidly moving cells. In slower moving cells, retrograde flow decreased, whereas protrusion rate and cell speed increased. These results suggest that there are two mechanisms for producing retrograde flow. One involves slippage between the cytoskeleton and adhesions, that decreases traction force production. The other involves slippage between adhesions and the substratum, which increases traction force production. We conclude that a biphasic relationship exists between retrograde actin flow and adhesiveness in moving keratocytes.
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Affiliation(s)
- Carlos Jurado
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT 06269, USA
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Pouliot R, Azhari R, Qanadilo HF, Mahmood TA, Triantafyllou MS, Langer R. Tissue engineering of fish skin: behavior of fish cells on poly(ethylene glycol terephthalate)/poly(butylene terephthalate) copolymers in relation to the composition of the polymer substrate as an initial step in constructing a robotic/living tissue hybrid. ACTA ACUST UNITED AC 2004; 10:7-21. [PMID: 15009926 DOI: 10.1089/107632704322791655] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
This study presents the development of a biosynthetic fish skin to be used on aquatic robots that can emulate fish. Smoothness of the external surface is desired in improving high propulsive efficiency and maneuvering agility of autonomous underwater vehicles such as the RoboTuna (Triantafyllou, M., and Triantafyllou, G. Sci. Am. 272, 64, 1995). An initial step was to determine the seeding density and select a polymer for the scaffolds. The attachment and proliferation of chinook salmon embryo (CHSE-214) and brown bullhead (BB) cells were studied on different compositions of a poly(ethylene glycol terephthalate) (PEGT) and poly(butylene terephthalate) (PBT) copolymer (Polyactive). Polymer films were used, cast of three different compositions of PEGT/PBT (weight ratios of 55/45, 60/40, and 70/30) and two different molecular masses of PEGT (300 and 1000 Da). When a 55 wt% and a 300-Da molecular mass form of PEGT was used, maximum attachment and proliferation of CHSE-214 and BB cells were achieved. Histological studies and immunostaining indicate the presence of collagen and cytokeratins in the extracellular matrix formed after 14 days of culture. Porous scaffolds of PEGT/PBT copolymers were also used for three-dimensional tissue engineering of fish skin, using BB cells. Overall, our results indicate that fish cells can attach, proliferate, and express fish skin components on dense and porous Polyactive scaffolds.
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Affiliation(s)
- Roxane Pouliot
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139-4307, USA
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