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1.
Eur Rev Med Pharmacol Sci ; 21(19): 4346-4349, 2017 Oct.
Article in English | MEDLINE | ID: mdl-29077162

ABSTRACT

OBJECTIVE: The aim of this study was to examine the effects of stent-assisted coiling embolization of middle cerebral artery (MCA) trifurcation wide-necked aneurysms in clinical practice. PATIENTS AND METHODS: 57 patients with MCA trifurcation wide-necked aneurysms underwent stent-assisted coiling embolization using a solitaire AB stent. All 57 patients completed the surgery successfully. Embolization efficacy was graded according to the modified Raymond scale. RESULTS: There were 52 cases of complete embolization, 4 cases of residual aneurysm neck, and 1 case of residual aneurysm body. 50 patients participated in a 6-36-month follow-up. There has not been observed any aneurysm rupture and hemorrhage. 50 patients received digital subtraction angiography (DSA) re-examination; 46 patients presenting complete embolization had no aneurysm relapses; 3 patients had residual aneurysm neck demonstrated; 1 patient had no aneurysm neck and others 2 were in stable condition. Finally, the patient with residual aneurysm body showed no sign during follow-up reexamination. CONCLUSIONS: Stent-assisted coiling embolization of intracranial wide-necked aneurysms using the solitaire AB stent was safe and effective.


Subject(s)
Angiography, Digital Subtraction/methods , Embolization, Therapeutic/methods , Stents , Adult , Aged , Cerebral Angiography/methods , Female , Humans , Intracranial Aneurysm/surgery , Male , Middle Aged , Middle Cerebral Artery , Treatment Outcome
2.
Eur Rev Med Pharmacol Sci ; 21(2): 292-296, 2017 01.
Article in English | MEDLINE | ID: mdl-28165559

ABSTRACT

OBJECTIVE: To aim at the efficacies of surgical clipping and endovascular embolization for oculomotor nerve palsy (ONP) as treatments for posterior communicating artery aneurysm (PcoAA), and the comparison and various influencing factors of the treatments. PATIENTS AND METHODS: An analysis of the clinical data of 52 enrolled PcoAA patients with ONP who had treatment in the Department of Neurosurgery in Anhui Provincial Hospital from January 2011 to June 2015 was conducted. There were 23 patients among a total underwent surgical clippings and others 29 patients received endovascular embolization treatment. Then, the age, gender, aneurysm size and rupture status, onset duration, preoperative ONP severity and postoperative recovery degree of ONP of patients in the two groups were compared. RESULTS: The final ONP outcomes of the 52 PcoAA patients consisted of 27 full recovery patients (51.9%), 21 partial recovery patients (40.4%), and 4 no recovery patients (7.7%). (1) Within the 23 patients in the surgical clipping group, subarachnoid hemorrhage (SAH) occurred in 16 patients, and no SAH occurrence in the other 7 patients; the final ONP evaluation showed 18 patients fully recovered (78.3%) and 5 patients partially recovered (21.7%). Within the 29 patients in the endovascular embolization group, SAH occurred in 18 patients, and no SAH occurrence in the other 11 patients; the final ONP evaluation showed 9 patients fully recovered (31%), 16 patients partially recovered in 16 patients (55.2%) and 4 no recovery patients (13.8%). (2) The postoperative ONP recovery was analyzed with multivariate logistic regression, and the treatment method was an independent factor for ONP recovery (OR = 0.041, 95% CI: 0.007-0.261, p < 0.01). CONCLUSIONS: When compared with the endovascular embolization, the surgical clipping showed a better efficacy in the recovery from PcoAA related ONP.


Subject(s)
Embolization, Therapeutic , Intracranial Aneurysm/surgery , Oculomotor Nerve Diseases/surgery , Adult , Aged , Female , Humans , Male , Middle Aged , Paralysis/physiopathology , Recovery of Function , Retrospective Studies , Subarachnoid Hemorrhage , Treatment Outcome
3.
Int Angiol ; 31(6): 534-43, 2012 Dec.
Article in English | MEDLINE | ID: mdl-23222931

ABSTRACT

AIM: Most applications of gradual pressure-decline compressing stockings (GPDCS) are used in the United States and Western European countries, with over a decade of clinical experiments. Up to know, there is no standard establishment of gradual pressure-decline compressing stockings for Asian patients with venous insufficiency and varicose vein formations. METHODS: We collected data on volunteer candidates of varicose vein for general measurements and assessments and magnetic resonance imaging (MRI) by non-contrast enhanced MRV techniques, and for post processing data analysis. RESULTS: Clinical use of GPCDS provide a mild to moderate improvement in the varicose vein conditions of patients with deep venous insufficiency by improving their deep vein circulation, by general measurements; recording major symptoms and complaint; comfort and stretching/flexibility to the candidates after using GPDCS; and area changes/flow velocity changes/available hemoglobin changes in deep veins monitored by MRI. CONCLUSION: The benefits and data collected in these results may help in developing compression stockings standards in Taiwanese and Asian countries, and to establishing criterias for product sizes, compression levels, and related parameters.


Subject(s)
Asian People , Magnetic Resonance Imaging, Cine , Stockings, Compression , Varicose Veins/therapy , Venous Insufficiency/therapy , Adult , Blood Flow Velocity , Female , Humans , Male , Middle Aged , Patient Satisfaction , Predictive Value of Tests , Regional Blood Flow , Stockings, Compression/adverse effects , Taiwan/epidemiology , Time Factors , Treatment Outcome , Varicose Veins/diagnosis , Varicose Veins/ethnology , Varicose Veins/physiopathology , Venous Insufficiency/diagnosis , Venous Insufficiency/ethnology , Venous Insufficiency/physiopathology
4.
Vet Microbiol ; 127(1-2): 136-41, 2008 Feb 05.
Article in English | MEDLINE | ID: mdl-17889456

ABSTRACT

To understand the nationwide seroprevalence of bovine herpesvirus type 1 (BoHV-1) infection of cows in China, 1344 sera of dairy cows from 29 provinces and 765 sera from 6 herds in Hubei province were collected with stratified random sampling. Another 483 sera from imported cows were included. The serum antibody was tested by BoHV-1 gG ELISA. The results demonstrated that the overall nationwide seroprevalence was 35.8% (481/1344), while the prevalence for individual province ranged from 12.1% to 77.8%. Although each province had positive samples, the prevalence was clustered in areas based on the cow population size. In Hubei Province, the overall seroprevalence was 22.2% (170/765) while the prevalence for individual farms varied greatly from 0.0% to 41.5%. The sera from imported cows had a moderate prevalence of 21.7% (105/483).


Subject(s)
Antibodies, Viral/blood , Herpesvirus 1, Bovine/physiology , Infectious Bovine Rhinotracheitis/epidemiology , Animals , Cattle , China/epidemiology , Enzyme-Linked Immunosorbent Assay/veterinary , Female , Infectious Bovine Rhinotracheitis/blood , Infectious Bovine Rhinotracheitis/virology , Seroepidemiologic Studies
5.
J Biol Chem ; 276(33): 31368-75, 2001 Aug 17.
Article in English | MEDLINE | ID: mdl-11399752

ABSTRACT

Endothelial cells (ECs) are constantly subjected to hemodynamic forces including cyclic pressure-induced strain. The role of protein kinase C (PKC) in cyclic strain-treated ECs was studied. PKC activities were induced as cyclic strain was initiated. Cyclic strain to ECs caused activation of PKC-alpha and -epsilon. The translocation of PKC-alpha and -epsilon but not PKC-beta from the cytosolic to membrane fraction was observed. An early transient activation of PKC-alpha versus a late but sustained activation of PKC-epsilon was shown after the onset of cyclic strain. Consistently, a sequential association of PKC-alpha and -epsilon with the signaling molecule Raf-1 was shown. ECs treated with a PKC inhibitor (calphostin C) abolished the cyclic strain-induced Raf-1 activation. ECs under cyclic strain induced a sustained activation of extracellular signal-regulated protein kinases (ERK1/2), which was inhibited by treating ECs with calphostin C. ECs treated with a specific Ca(2+)-dependent PKC inhibitor (Go 6976) showed an inhibition in the early phase of ERK1/2 activation but not in the late and sustained phase. ECs transfected with the antisense to PKC-alpha, the antisense to PKC-epsilon, or the inhibition peptide to PKC-epsilon reduced strain-induced ERK1/2 phosphorylation in a temporal manner. PKC-alpha mediated mainly the early ERK1/2 activation, whereas PKC-epsilon was involved in the sustained ERK1/2 activation. Strained ECs increased transcriptional activity of Elk1 (an ERK1/2 substrate). ECs transfected with the antisense to each PKC isoform reduced Elk1 and monocyte chemotactic protein-1 promotor activity. Our findings conclude that a sequential activation of PKC isoform (alpha and epsilon) contribute to Raf/ERK1/2 activation, and PKC-epsilon appears to play a key role in endothelial adaptation to hemodynamic environment.


Subject(s)
DNA-Binding Proteins , Endothelium, Vascular/enzymology , Isoenzymes/physiology , Mitogen-Activated Protein Kinase 1/metabolism , Mitogen-Activated Protein Kinases/metabolism , Protein Kinase C/physiology , Proto-Oncogene Proteins c-raf/metabolism , Proto-Oncogene Proteins , Transcription Factors , Animals , Autoantigens/genetics , Calcium/metabolism , Cattle , Enzyme Activation , Mitogen-Activated Protein Kinase 3 , Oligonucleotides, Antisense/pharmacology , Potassium Channels/genetics , Protein Kinase C-alpha , Protein Kinase C-epsilon , Stress, Mechanical , Transcription, Genetic , ets-Domain Protein Elk-1
6.
Chin J Physiol ; 42(2): 103-11, 1999 Jun 30.
Article in English | MEDLINE | ID: mdl-10513606

ABSTRACT

Our previous studies have shown that cyclic strain to endothelial cells (ECs) increases reactive oxygen species (ROS) that act as second messengers. The potential impact of these enhanced ROS levels on ECs was examined by studying the antioxidant activities and heme oxygenase-1 (HO-1) expression in strained ECs. Cyclic strain to ECs increased lipid peroxidation and augmented oxidation of low-density lipoproteins. ECs subjected to strain increased their superoxide dismutase activities. Concomitantly, glutathione peroxidase activities increased in 3 to 6 hr and returned to basal level 24 hr after continuous cyclic strain treatment. A decrease of glutathione (GSH) was accompanied with an increase of oxidized glutathione (GSSH) level in ECs 3 to 6 hr after strain treatment. This was followed with a return of both GSH and GSSH to basal levels in 24 hr. Consistently, H2O2 treatment of ECs decreased the GSH/GSSG ratio. ECs pretreated with catalase abolished the strain-induced change in GSH/GSSG. Strain treatment, similar to H2O2 exposure, induced HO-1 expression in a time-dependent manner. This induction was inhibited after treating ECs with catalase or free radical scavenger. ECs treated with N-acetyl-cysteine abolished HO-1 gene induction. Our results suggest that cyclic strain-induced ROS cause a transient increase of glutathione peroxidase activity that results in a decrease of GSH level in ECs and that this decrease is crucial to HO-1 induction.


Subject(s)
Endothelium, Vascular/metabolism , Cells, Cultured , Endothelium, Vascular/cytology , Endothelium, Vascular/enzymology , Gene Expression Regulation/physiology , Glutathione/metabolism , Glutathione Disulfide/metabolism , Glutathione Peroxidase/metabolism , Heme Oxygenase (Decyclizing)/genetics , Heme Oxygenase-1 , Humans , Intracellular Membranes/metabolism , Lipid Peroxides/biosynthesis , Membrane Proteins , Oxidation-Reduction , Periodicity , Reactive Oxygen Species/metabolism , Stress, Mechanical , Superoxide Dismutase/metabolism , Transcriptional Activation
7.
Circ Res ; 84(7): 804-12, 1999 Apr 16.
Article in English | MEDLINE | ID: mdl-10205148

ABSTRACT

Endothelial cells (ECs) exposed to cyclic strain induce gene expression. To elucidate the signaling mechanisms involved, we studied the effects of cyclic strain on ECs by using early growth response-1 (Egr-1) as a target gene. Cyclic strain induced a transient increase of Egr-1 mRNA levels that resulted in an increase of binding of nuclear proteins to the Egr-1 binding sequences in the platelet-derived growth factor-A promoter region. ECs subjected to strain enhanced Egr-1 transcription as revealed by promoter activities. Catalase pretreatment inhibited this induction. ECs, transfected with a dominant positive mutant of Ras (RasL61), increased Egr-1 promoter activities. In contrast, transfection with a dominant negative mutant of Ras (RasN17) attenuated this strain inducibility. ECs transfected with a dominant negative mutant of Raf-1 (Raf301) or the catalytically inactive mutant of extracellular signal-regulated kinase (ERK)-2 (mERK2) diminished strain-induced promoter activities. However, little effect on strain inducibility was observed in ECs transfected with a dominant negative mutant of Rac (RacN17) or a catalytically inactive mutant of JNK (JNK[K-R]). Consistently, strain-induced Egr-1 expression was inhibited after ECs were treated with a specific inhibitor (PD98059) to mitogen-activated protein kinase kinase. Moreover, strain to ECs induced mitogen-activated protein kinase/ERK activity. The activation of the ERK pathway was further substantiated by an increase of strain-induced transcriptional activity of Elk1, an ERK substrate. This strain-induced ERK activity was attenuated after ECs were treated with N-acetylcysteine or catalase. Consequently, this Egr-1 gene induction was abolished after ECs were treated with N-acetylcysteine or catalase. Deletion analyses of the promoter region (-698 bp) indicated that cyclic strain and H2O2 shared a common serum response element. Our data clearly indicate that cyclic strain-induced Egr-1 expression is mediated mainly via the Ras/Raf-1/ERK pathway and that strain-induced reactive oxygen species can modulate Egr-1 expression at least partially via this signaling pathway.


Subject(s)
Calcium-Calmodulin-Dependent Protein Kinases/metabolism , Endothelium, Vascular/enzymology , Proto-Oncogene Proteins c-raf/physiology , Signal Transduction/physiology , ras Proteins/physiology , Animals , Aorta/cytology , Cattle , Cells, Cultured , DNA-Binding Proteins/genetics , DNA-Binding Proteins/metabolism , Endothelium, Vascular/chemistry , Endothelium, Vascular/cytology , Extracellular Space/physiology , Gene Expression/physiology , Genes, Reporter , Hydrogen Peroxide/metabolism , Mitogen-Activated Protein Kinase 1 , Nuclear Proteins/metabolism , Platelet-Derived Growth Factor/genetics , Platelet-Derived Growth Factor/metabolism , Promoter Regions, Genetic/physiology , RNA, Messenger/analysis , Reactive Oxygen Species/metabolism , Serum Response Factor , Transcription Factors/genetics , Transcription Factors/metabolism , Transcriptional Activation/physiology , Zinc Fingers/physiology
8.
Hypertension ; 31(1): 125-30, 1998 Jan.
Article in English | MEDLINE | ID: mdl-9449403

ABSTRACT

Vascular endothelial cells (ECs) are constantly subjected to pressure-induced strain. We have previously demonstrated that strain can induce intercellular adhesion molecule-1 (ICAM-1) expression in ECs. The molecular mechanisms of gene induction by strain, however, remain unclear. Recent evidence suggests that intracellular reactive oxygen species (ROS) may act as second messengers. The potential role of ROS in strain-induced ICAM-1 expression was examined. ECs grown on a flexible membrane base were deformed with various sinusoidal negative pressures to produce an average strain of 12%. Cyclic strain induced an increase in intracellular ROS measured by fluorescent intensity of dichlorofluorescein formed after peroxidation. Maximal levels of ROS were seen after 30 minutes. Levels subsequently decreased but remained elevated compared with unstrained groups. Concomitantly, a sustained increase of H2O2 decomposition activity was observed in strained ECs. Both ROS and H2O2 decomposition activity returned to basal levels after removal of the strain. ECs treated with an antioxidant (N-acetylcysteine or catalase) inhibited strain-induced ROS generation and ICAM-1 mRNA levels followed by decreased ICAM-1 expression on EC surfaces. This inhibition may account for the reduced monocytic cell adhesion in antioxidant-treated ECs but not in strained controls. Our findings indicate that cyclic strain-induced monocyte adhesion to ECs is mediated, at least in part, by an increase of ICAM-1 gene expression via the elevation of ROS levels in strained ECs. Our results support the importance of intracellular ROS in the modulation of hemodynamic force-induced endothelial responses.


Subject(s)
Endothelium, Vascular/metabolism , Gene Expression Regulation , Intercellular Adhesion Molecule-1/metabolism , Reactive Oxygen Species/metabolism , Antioxidants/pharmacology , Cells, Cultured , Hemorheology , Humans , Intercellular Adhesion Molecule-1/genetics , RNA, Messenger , Transcriptional Activation
9.
Hypertension ; 28(3): 386-91, 1996 Sep.
Article in English | MEDLINE | ID: mdl-8794821

ABSTRACT

Since endothelial cells are constantly subjected to pressure-induced strain, we examined how cyclic strain affects the expression of intercellular adhesion molecule-1 (ICAM-1). Endothelial cells grown on a flexible membrane base were deformed by different sinusoidal negative pressures (-10, -15, or -20 kPa) to produce an average strain of 9%, 11%, and 12%, respectively, for various times. The release of the soluble form of ICAM-1 from strained endothelial cells increased in a time- and strain-dependent manner. Using flow cytometric analysis, we showed the induction of ICAM-1 expression on the endothelial cell surface to depend on both time and the amount of strain. Northern blot analysis revealed a sustained, approximately 1.8-fold increase in ICAM-1 mRNA levels in 11% strained cells. Strain-induced expression of ICAM-1 correlated with a strain-dependent increase in adhesion of monocytic cells to strained cells. This increase in monocytic cell adhesion could be partially inhibited by pretreatment of strained cells with antibody to ICAM-1. These results indicate that mechanical strain can stimulate the expression of ICAM-1 by endothelial cells and thus contribute to the increased adhesion of monocytes to strained cells. Such strain-induced expression of ICAM-1 may contribute to the trapping of monocytes on local vascular walls where strain is high and to the initiation of atherogenesis, thus providing a possible link between hypertension and atherogenesis.


Subject(s)
Endothelium, Vascular/physiology , Intercellular Adhesion Molecule-1/metabolism , Monocytes/physiology , Cell Adhesion/physiology , Cells, Cultured , Endothelium, Vascular/cytology , Humans , Intercellular Adhesion Molecule-1/genetics , RNA, Messenger/metabolism , Solubility , Stress, Mechanical
10.
Biochem Biophys Res Commun ; 225(1): 100-5, 1996 Aug 05.
Article in English | MEDLINE | ID: mdl-8769100

ABSTRACT

The molecular mechanisms of the endothelial fibrinolytic activities modulated by mechanical strain are not clear. Endothelial cells (ECs) grown on a flexible membrane base were deformed with sinusoidal negative pressures to produce an average strain of 12%. Cyclic strain induced PAI-1 release in a time-dependent manner. Strain cells resulted in a 5-fold increase in PAI-1 release. Strain induced a sustained elevated level in intracellular reactive oxygen species (ROS). Concomitantly, a sustained increase of catalase activity was observed. Both ROS and catalase activity returned to basal levels with the removal of strain. ECs pretreated with antioxidant, N-acetyl-cysteine, abolished the strain-induced ROS generation as well as strained-induced PAI-1 release. Our results indicate that cyclic strain-induced PAI-1 secretion may be mediated by an increase in ROS generation and thus emphasizes the importance of intracellular ROS in the modulation of hemodynamic force-induced cellular response of ECs.


Subject(s)
Acetylcysteine/pharmacology , Antioxidants/pharmacology , Endothelium, Vascular/physiology , Plasminogen Activator Inhibitor 1/biosynthesis , Reactive Oxygen Species/metabolism , Catalase/metabolism , Cells, Cultured , Culture Techniques/methods , Endothelium, Vascular/cytology , Endothelium, Vascular/drug effects , Humans , Kinetics , Membranes, Artificial , Plasminogen Activator Inhibitor 1/metabolism , Pressure , Stress, Mechanical , Time Factors , Umbilical Cord
11.
Am J Physiol ; 270(4 Pt 2): H1462-8, 1996 Apr.
Article in English | MEDLINE | ID: mdl-8967390

ABSTRACT

The effects of mechanical strain on monocyte chemotactic protein-1 (MCP-1) secretion were examined on human endothelial cells (ECs) grown on a flexible membrane base. MCP-1 release into culture medium from strained ECs was demonstrated to be time and strain dose dependent. Northern blot analysis demonstrated a mainly serum-independent 1.8-fold induction of MCP-1 mRNA levels in ECs strained at 15 kPa compared with unstrained controls. ECs treated with actinomycin D abolished this strain-induced expression. Strained ECs at the periphery of wells showed higher MCP-1 gene expression than ECs at the center. Pretreatment of ECs with either cytochalasin D or phalloidin did not abolish strain-induced gene expression. ECs pretreated with stretch-activated ion channel blocker gadolinium or with ryanodine to deplete intracellular stored Ca2+ strongly inhibited the strain-induced MCP-1 levels. We conclude that 1) cyclical strain can modulate the secretion of MCP-1 in a dose-dependent manner, 2) strain-induced MCP-1 production is mediated by increasing MCP-1 mRNA levels via transcription, 3) cytoskeletal rearrangement is not essential for this strain-induced MCP-1 expression, and 4) both Ca2+ influx via stretch-activated ion channels and intracellular Ca2+ release contribute to the strain-induced effect. Such strain-induced MCP-1 secretion might contribute to the trapping of monocytes in the subendothelial space to initiate atherogenesis.


Subject(s)
Chemokine CCL2/metabolism , Endothelium, Vascular/metabolism , Blotting, Northern , Calcium/metabolism , Cells, Cultured , Chemokine CCL2/genetics , Culture Media, Serum-Free , Endothelium, Vascular/cytology , Humans , RNA, Messenger/metabolism , Stress, Mechanical , Time Factors
12.
Circ Res ; 77(2): 294-302, 1995 Aug.
Article in English | MEDLINE | ID: mdl-7614716

ABSTRACT

Monocyte chemotactic protein-1 (MCP-1), a potent monocyte chemoattractant secreted by endothelial cells (ECs), is believed to play a key role in the early events of atherogenesis. Since vascular ECs are constantly subjected to mechanical stresses, we examined how cyclic strain affects the expression of the MCP-1 gene in human ECs grown on a flexible membrane base deformed by sinusoidal negative pressure (peak level, -16 kPa at 60 cycles per minute). Northern blot analysis demonstrated that the MCP-1 mRNA levels in ECs subjected to strain for 1, 5, or 24 hours were double those in control ECs (P < .05). This strain-induced increase was mainly serum independent, and MCP-1 mRNA level returned to its control basal level 3 hours after release of strain. Culture media from strained ECs contained approximately twice the MCP-1 concentration and more than twice the monocyte chemotactic activity of media from control ECs (P < .05). Pretreatment of collected media with anti-MCP-1 antibody suppressed such activity. Monocyte adhesion to ECs subjected to strain for 12 hours was 1.8-fold greater than adhesion to unstrained control ECs (P < .05). A protein kinase C inhibitor, calphostin C, abolished the strain-induced MCP-1 gene expression. In addition, cAMP- or cGMP-dependent protein kinase inhibitors (KT5720 and KT5823, respectively) partially inhibited such expression. Pretreatment with EGTA or the intracellular Ca2+ chelator BAPTA/AM strongly suppressed the strain-induced MCP-1 mRNA. Verapamil, a Ca2+ channel blocker, greatly reduced MCP-1 mRNA levels in both strained and unstrained ECs.(ABSTRACT TRUNCATED AT 250 WORDS)


Subject(s)
Chemotactic Factors/genetics , Cytokines/genetics , Endothelium, Vascular/cytology , Endothelium, Vascular/metabolism , Gene Expression , Monocytes/physiology , Stress, Mechanical , Analysis of Variance , Arteriosclerosis/etiology , Calcium/metabolism , Cells, Cultured , Chemokine CCL2 , Chemotactic Factors/analysis , Endothelium, Vascular/enzymology , Enzyme-Linked Immunosorbent Assay , Humans , In Vitro Techniques , Protein Kinases/metabolism , RNA, Messenger/analysis , Signal Transduction , Tissue Adhesions , Umbilical Veins
13.
Mol Cell Biochem ; 136(2): 113-6, 1994 Jul 27.
Article in English | MEDLINE | ID: mdl-7845364

ABSTRACT

Aorta smooth myosin contains two types of light chain, LC20 and LC17, which fold together with the N-terminal region of each heavy chain to form the globular head region of myosin. We demonstrate an altered conformation of LC20 after its separation from heavy chain by high concentrations of urea, on the basis of the following evidence: 1) A polyclonal antibody against LC20 was not able to recognize this conformationally altered form; 2) Myosin reconstituted from heavy chains and urea-dissociated light chains exhibited extremely low ATPase activity. Circular dichroism unfolding profiles showed that light chains dissociated from heavy chains by SDS appeared to be more stable than those generated by urea dissociation.


Subject(s)
Myosins/chemistry , Animals , Cattle , Chickens , Protein Conformation
14.
J Cell Sci ; 107 ( Pt 6): 1389-402, 1994 Jun.
Article in English | MEDLINE | ID: mdl-7962183

ABSTRACT

We have recently shown that the nuclear mitotic apparatus protein (NuMA) is composed of at least three isoforms that differ mainly at the carboxy terminus, and are generated by alternative splicing of a common mRNA precursor from a single NuMA gene (J. Cell Sci. (1993) 104, 249-260). Transient expression of human NuMA-1 isoform (T33/p230) in Chinese hamster ovary polyoma (CHOP) cells showed that NuMA-1 was present in interphase nuclei and was concentrated at the polar regions of the spindle apparatus in mitotic cells. However, expression of two other isoforms (NuMA-m and -s) revealed a distinct subcellular localization. NuMA-m (U4/p195) and NuMA-s (U6/p194) were present in the interphase cytosol and appeared to be mainly located at the centrosomal region. When cells entered into mitosis, however, NuMA-m and -s moved to the mitotic spindle pole. Analysis of a series of linker scanning-mutants and NuMA/beta-galactosidase chimeric proteins showed that residues 1972-2007 of NuMA-1 constitute a novel nuclear localization signal (NLS) and residues 1538-2115 are necessary and sufficient for spindle association. Further analysis of the NLS by site-specific mutagenesis indicated that Lys1988 is essential for nuclear targeting, whereas Arg1984 is not. These results have allowed us tentatively to assign specific biological activities to distinct structural domains of the NuMA polypeptide.


Subject(s)
Nuclear Proteins/physiology , Spindle Apparatus/physiology , Subcellular Fractions/chemistry , Amino Acid Sequence , Animals , Antigens, Nuclear , Antigens, Polyomavirus Transforming/biosynthesis , Base Sequence , Biological Transport , CHO Cells , Cell Cycle , Cell Cycle Proteins , Cricetinae , Gene Expression Regulation , Humans , Molecular Sequence Data , Mutagenesis, Site-Directed , Nuclear Matrix-Associated Proteins , Nuclear Proteins/genetics , Protein Sorting Signals/metabolism , RNA Splicing , Recombinant Fusion Proteins/metabolism , Transfection
15.
Cytobios ; 68(272): 15-22, 1991.
Article in English | MEDLINE | ID: mdl-1778091

ABSTRACT

Cholesterol, a major lipid component of the plasma membrane, is thought to have profound effects on the structure and function of cells. Most animal tissues are capable of synthesizing cholesterol de novo from acetate; however, there are relatively few mammalian cells in vitro expressing an absolute requirement for an exogenous source of cholesterol. In this paper, it was shown that both IR983F (983) rat myeloma cells and P3X63-Ag8-U1 (P3U1) mouse myeloma cells which had been cultivated in serum-free medium containing cholesterol for more than 6 months still required cholesterol in vitro for growth in serum-free medium. Optimal growth of 983 and P3U1 occurred in cholesterol concentrations of 15 and 5 micrograms/ml, respectively. Moreover, it was demonstrated that the cholesterol could be replaced by human low density lipoprotein in a concentration of 10 micrograms/ml but not by mevalonic acid lactone. In contrast to the parental myeloma cells, hybridoma cells derived from the mouse myeloma cells which had been cultivated in serum-free medium containing cholesterol for more than 6 months did not require cholesterol.


Subject(s)
Cell Division , Cholesterol/physiology , Animals , Culture Media, Serum-Free , Hybridomas , Kinetics , Mevalonic Acid/analogs & derivatives , Mevalonic Acid/pharmacology , Mice , Multiple Myeloma , Rats , Tumor Cells, Cultured
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