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1.
Arkh Patol ; 85(2): 53-59, 2023.
Article in Russian | MEDLINE | ID: mdl-37053355

ABSTRACT

Tumor invasion plays a key role in the progression of tumors. This process is regulated by the interactions of cells and tissues, in which physical, cellular and molecular determinants undergo changes throughout the entire period of progression of tumor growth. Tumor invasion is triggered and maintained by specialized signal cascades that control the dynamic state of the cytoskeleton in tumor cells, the processes of rearrangement of cell-matrix and intercellular connections, followed by cell migration to neighboring tissues. Studying the mechanisms of regulation of cell motor activity and determining its main regulators is an important task for understanding the pathophysiology of tumor growth. Caldesmon is an actin, myosin and calmodulin binding protein. It is involved in the regulation of smooth muscle contraction by inhibiting actin and myosin binding, in the formation of actin stress fibers, and in the transport of intracellular granules. Currently, caldesmon is considered as a potential biomarker of tumor cell invasion, migration, and metastasis. The study of signaling molecules involved in tumor progression, such as caldesmon, is necessary to predict response to chemotherapy and radiotherapy. This review highlights the main functions of caldesmon and analyzes its role in oncological pathology.


Subject(s)
Actins , Calmodulin-Binding Proteins , Humans , Calmodulin-Binding Proteins/genetics , Calmodulin-Binding Proteins/metabolism , Calmodulin-Binding Proteins/pharmacology , Cytoskeleton/metabolism , Myosins/metabolism
2.
Mol Cancer ; 21(1): 150, 2022 07 21.
Article in English | MEDLINE | ID: mdl-35864549

ABSTRACT

BACKGROUND: Long non-coding RNAs (lncRNAs) are implicated in the development of multiple cancers. In our previous study, we demonstrated that HDAC1/4-mediated silencing of microRNA-200b (miR-200b) enhances docetaxel (DTX)-resistance of human lung adenocarcinoma (LAD) cells. METHODS AND RESULTS: Herein, we probed the function of LncRNA MARCKSL1-2 (MARCKSL1-transcript variant 2, NR_052852.1) in DTX resistance of LAD cells. It was found that MARCKSL1-2 expression was markedly reduced in DTX-resistant LAD cells. Through gain- or loss- of function assays, colony formation assay, EdU assay, TUNEL assay, and flow cytometry analysis, we found that MARCKSL1-2 suppressed the growth and DTX resistance of both parental and DTX-resistant LAD cells. Moreover, we found that MARCKSL1-2 functioned in LAD through increasing miR-200b expression and repressing HDAC1. Mechanistically, MARCKSL1-2 recruited the suppressor of zeste 12 (SUZ12) to the promoter of histone deacetylase 1 (HDAC1) to strengthen histone H3 lysine 27 trimethylation (H3K27me3) of HDAC1 promoter, thereby reducing HDAC1 expression. MARCKSL1-2 up-regulated miR-200b by blocking the suppressive effect of HDAC1 on the histone acetylation modification at miR-200b promoter. Furthermore, in vivo analysis using mouse xenograft tumor model supported that overexpression of MARCKSL1-2 attenuated the DTX resistance in LAD tumors. CONCLUSIONS: We confirmed that MARCKSL1-2 alleviated DTX resistance in LAD cells by abolishing the inhibitory effect of HDAC1 on miR-200b via the recruitment of SUZ12. MARCKSL1-2 could be a promising target to improve the chemotherapy of LAD.


Subject(s)
Adenocarcinoma , Lung Neoplasms , MicroRNAs , RNA, Long Noncoding , Adenocarcinoma/genetics , Animals , Calmodulin-Binding Proteins/genetics , Calmodulin-Binding Proteins/metabolism , Calmodulin-Binding Proteins/pharmacology , Cell Line, Tumor , Cell Proliferation , Docetaxel/pharmacology , Drug Resistance, Neoplasm/genetics , Gene Expression Regulation, Neoplastic , Histone Deacetylase 1/genetics , Humans , Lung/metabolism , Lung Neoplasms/drug therapy , Lung Neoplasms/genetics , Lung Neoplasms/pathology , Mice , MicroRNAs/genetics , MicroRNAs/metabolism , Microfilament Proteins , RNA, Long Noncoding/genetics , Taxoids/pharmacology
3.
Mol Ther ; 29(8): 2456-2468, 2021 08 04.
Article in English | MEDLINE | ID: mdl-33781914

ABSTRACT

The inherited childhood blindness caused by mutations in NPHP5, a form of Leber congenital amaurosis, results in abnormal development, dysfunction, and degeneration of photoreceptors. A naturally occurring NPHP5 mutation in dogs leads to a phenotype that very nearly duplicates the human retinopathy in terms of the photoreceptors involved, spatial distribution of degeneration, and the natural history of vision loss. We show that adeno-associated virus (AAV)-mediated NPHP5 gene augmentation of mutant canine retinas at the time of active degeneration and peak cell death stably restores photoreceptor structure, function, and vision with either the canine or human NPHP5 transgenes. Mutant cone photoreceptors, which failed to form outer segments during development, reform this structure after treatment. Degenerating rod photoreceptor outer segments are stabilized and develop normal structure. This process begins within 8 weeks after treatment and remains stable throughout the 6-month posttreatment period. In both photoreceptor cell classes mislocalization of rod and cone opsins is minimized or reversed. Retinal function and functional vision are restored. Efficacy of gene therapy in this large animal ciliopathy model of Leber congenital amaurosis provides a path for translation to human treatment.


Subject(s)
Calmodulin-Binding Proteins/administration & dosage , Dependovirus/genetics , Leber Congenital Amaurosis/therapy , Retinal Cone Photoreceptor Cells/pathology , Animals , Calmodulin-Binding Proteins/pharmacology , Disease Models, Animal , Dogs , Electroretinography , Genetic Therapy , Genetic Vectors/administration & dosage , Humans , Leber Congenital Amaurosis/genetics , Treatment Outcome
4.
J Biomed Mater Res B Appl Biomater ; 107(1): 29-36, 2019 01.
Article in English | MEDLINE | ID: mdl-29504239

ABSTRACT

Although it only accounts for approximately 5% of all female cancer cases, ovarian cancer (OC) ranks as the fifth leading cause of death due to cancer in women. We have evaluated the potential of an orally administered microparticulate vaccine incorporating an immunodominant epitope peptide derived from the cancer/testis antigen sperm protein 17 (SP17) aberrantly expressed in OC, to retard the progression of the disease. The peptide antigen and the immune-stimulatory toll-like receptor 9 ligand CpG oligonucleotide were incorporated into spray dried microparticles composed of enteric and sustained release polymers together with the Aleuria aurantia lectin targeting microfold cells present in the gut-associated lymphoid tissue. These particles were administered via oral route to mice challenged week prior with SP17-expressing ID8 OC cells. Analysis of splenocytes harvested from vaccinated mice revealed strong activation of IFN-γ+/CD8+ lymphocytes in response to re-stimulation with the SP17 antigen. Moreover, vaccinated animals showed significant retardation of ascites/tumor volume in comparison to placebo-treated animals four weeks after the tumor challenge (p = 0.005). Taken together, our results suggest that vaccination against SP17 using orally administered microparticles could potentially be used as an effective consolidation strategy for OC patients with residual tumor or high probability for relapse following first-line treatments. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 107B: 29-36, 2019.


Subject(s)
Antigens, Neoplasm , CD8-Positive T-Lymphocytes/immunology , Calmodulin-Binding Proteins , Cancer Vaccines , Membrane Proteins , Oligodeoxyribonucleotides , Ovarian Neoplasms , Administration, Oral , Animals , Antigens, Neoplasm/immunology , Antigens, Neoplasm/pharmacology , CD8-Positive T-Lymphocytes/pathology , Calmodulin-Binding Proteins/immunology , Calmodulin-Binding Proteins/pharmacology , Cancer Vaccines/immunology , Cancer Vaccines/pharmacology , Cell Line, Tumor , Delayed-Action Preparations/pharmacology , Female , Humans , Membrane Proteins/immunology , Membrane Proteins/pharmacology , Mice , Mice, Nude , Oligodeoxyribonucleotides/immunology , Oligodeoxyribonucleotides/pharmacology , Ovarian Neoplasms/immunology , Ovarian Neoplasms/pathology , Ovarian Neoplasms/therapy , Xenograft Model Antitumor Assays
5.
Cancer ; 120(16): 2412-23, 2014 Aug 15.
Article in English | MEDLINE | ID: mdl-24798237

ABSTRACT

BACKGROUND: F-box protein 32 (FBXO32) (also known as atrogin-1), a member of the F-box protein family, has recently been identified as a transforming growth factor beta (TGF-ß)/Smad target gene involved in regulating cell survival, and it may be transcriptionally silenced by epigenetic mechanisms in some kinds of carcinomas, yet its role in esophageal squamous cell carcinoma (ESCC) has not been defined. METHODS: The role of FBXO32 in ESCC and the correlation of FBXO32 methylation with a series of pathologic parameters were studied in a large cohort of patients with ESCC. RESULTS: Decreased messenger RNA (mRNA) expression and protein expression of FBXO32 were observed in esophageal cancer cell lines, and the silencing of FBXO32 could be reversed by treatment with 5-aza-2'-deoxycytidine or trichostatin A in the TE13 cell line. In addition, aberrant methylation of FBXO32 and histone deacetylation was capable of suppressing FBXO32 mRNA and protein expression in TE13 cells. Decreased mRNA and protein expression of FBXO32 was observed in ESCC tumor tissues and was associated with FBXO32 promoter methylation status. A positive correlation between FBXO32 and phosphorylated SMAD family members 2 and 3 expression and Smad4 protein expression also was observed in clinical specimens. FBXO32 methylation status and protein expression were independently associated with survival in patients with ESCC. CONCLUSIONS: FBXO32 may be a functional tumor suppressor. Its inactivation through promoter methylation could play an important role in ESCC carcinogenesis, and reactivation of the FBXO32 gene may have therapeutic potential and might be used as a prognostic marker for patients with ESCC.


Subject(s)
Carcinoma, Squamous Cell/genetics , DNA Methylation , Esophageal Neoplasms/genetics , Muscle Proteins/genetics , SKP Cullin F-Box Protein Ligases/genetics , Smad Proteins/metabolism , Transforming Growth Factor beta/metabolism , Adult , Aged , Azacitidine/analogs & derivatives , Azacitidine/pharmacology , Calmodulin-Binding Proteins/pharmacology , Carcinoma, Squamous Cell/metabolism , Cell Growth Processes/genetics , Decitabine , Esophageal Neoplasms/metabolism , Esophageal Squamous Cell Carcinoma , Female , Gene Silencing/drug effects , Humans , Hydroxamic Acids/pharmacology , Immunohistochemistry , Male , Middle Aged , Muscle Proteins/biosynthesis , Muscle Proteins/metabolism , Promoter Regions, Genetic , RNA, Messenger/biosynthesis , RNA, Messenger/genetics , SKP Cullin F-Box Protein Ligases/biosynthesis , SKP Cullin F-Box Protein Ligases/metabolism , Smad Proteins/biosynthesis , Smad Proteins/genetics , Transforming Growth Factor beta/biosynthesis , Transforming Growth Factor beta/genetics , Up-Regulation/drug effects
6.
Mol Med ; 19: 124-34, 2013 Jul 24.
Article in English | MEDLINE | ID: mdl-23670274

ABSTRACT

Disorders of the oxidative phosphorylation (OXPHOS) system frequently result in a severe multisystem disease with the consequence of early childhood death. Among these disorders, isolated complex I deficiency is the most frequently diagnosed, accounting for one-third of all cases of respiratory chain deficiency. We chose to focus on complex I deficiency, caused by mutation in the assembly factor chromosome 6, open reading frame 66 (C6ORF66; NADH dehydrogenase [ubiquinone] complex I assembly factor 4 [NDUFAF4]) protein. We used the approach of cell- and organelle-directed protein/enzyme replacement therapy, with the transactivator of transcription (TAT) peptide as the moiety delivery system. This step will enable us to deliver the wild-type assembly factor C6ORF66 into patient cells and their mitochondria, leading to the proper assembly and function of complex I and, as a result, to a functional OXPHOS system. We designed and constructed the TAT-ORF fusion protein by gene fusion techniques, expressed the protein in an Escherichia coli expression system and highly purified it. Our results indicate that TAT-ORF enters patients' cells and their mitochondria rapidly and efficiently. TAT-ORF is biologically active and led to an increase in complex I activity. TAT-ORF also increased the number of patient cells and improved the activity of their mitochondria. Moreover, we observed an increase in ATP production, a decrease in the content of mitochondria and a decrease in the level of reactive oxygen species. Our results suggest that this approach of protein replacement therapy for the treatment of mitochondrial disorders is a promising one.


Subject(s)
Calmodulin-Binding Proteins/pharmacology , Electron Transport Complex I/metabolism , Gene Products, tat/pharmacology , Mitochondrial Diseases/metabolism , Recombinant Fusion Proteins/pharmacology , Calmodulin-Binding Proteins/genetics , Cells, Cultured , Fibroblasts/drug effects , Fibroblasts/metabolism , Gene Products, tat/genetics , Humans , Mitochondrial Diseases/genetics
7.
Cardiovasc Drugs Ther ; 26(4): 321-30, 2012 Aug.
Article in English | MEDLINE | ID: mdl-22588788

ABSTRACT

Apoptosis in cardiovascular diseases is considered to be a major reason for heart failure. Caspase-independent apoptosis due to calpains and other proteases occurs due to increase in intracellular Ca(2+) levels which act on a feed-forward mechanism. Calpains are Ca(2+)-activated cysteine proteases present in the cytosol as inactive proenzymes. Calpastatin is most efficient and specific calpain inhibitor present in vivo. Earlier, we had reported the expression of novel high molecular weight calmodulin-binding protein (HMWCaMBP) in human and animal cardiac tissue and in very minute quantities in brains and lungs. HMWCaMBP showed calpastatin activity and was also found to be highly homologous to calpastatin I and calpastatin II. Decreased expression of HMWCaMBP was observed during ischemia as it is susceptible to proteolysis by calpains during ischemia-reperfusion. In normal myocardium, HMWCaMBP may protect its substrate from calpains. However, during an early stage of ischemia/reperfusion due to increased Ca(2+) influx, calpain activity often exceeds HMWCaMBP activity. This leads to proteolysis of HMWCaMBP and other protein substrates, resulting in cellular damage. The role of HMWCaMBP in ischemia/reperfusion is yet to be elucidated. The present review summarizes the developments in area of HMWCaMBP from the authors' laboratory and its potential for therapy.


Subject(s)
Calmodulin-Binding Proteins/pharmacology , Calpain/antagonists & inhibitors , Heart/drug effects , Reperfusion Injury/drug therapy , Animals , Apoptosis/drug effects , Calmodulin-Binding Proteins/metabolism , Calpain/metabolism , Heart/physiopathology , Humans , Molecular Weight , Reperfusion Injury/metabolism
8.
Neurobiol Aging ; 32(1): 1-14, 2011 Jan.
Article in English | MEDLINE | ID: mdl-20961659

ABSTRACT

The amyloid cascade hypothesis of Alzheimer's disease (AD) posits that the generation of ß-amyloid (Aß) triggers Tau neurofibrillary pathology. Recently a "17 kD" calpain-induced Tau fragment, comprising residues 45-230 (molecular weight [MW], 18.7 kD), was proposed to mediate Aß-induced toxicity. Here, we demonstrate that the "17 kD" fragment is actually much smaller, containing residues 125-230 (molecular weight, 10.7 kD). Inducing Tau phosphorylation by okadaic acid or mimicking phosphorylation by Glu mutations at the epitopes of Alzheimer-diagnostic antibodies AT100/AT8/PHF1 could not prevent the generation of this fragment. The fragment can be induced not only by Aß oligomers, but also by other cell stressors, e.g., thapsigargin (a Ca(2+)-ATPase inhibitor) or glutamate (an excitatory neurotransmitter). However, overexpression of neither Tau(45-230) nor Tau(125-230) fragment is toxic to Chinese hamster ovary (CHO) cells, neuroblastoma cells (N2a) or primary hippocampal neurons. Finally, the calpain-induced fragment can be observed both in Alzheimer's disease brains and in control normal human brains. We conclude that the 17 kD Tau fragment is not a mediator of Aß-induced toxicity, leaving open the possibility that upstream calpain activation might cause both Tau fragmentation and toxicity.


Subject(s)
Alzheimer Disease/metabolism , Calpain/pharmacology , Cerebral Cortex/metabolism , tau Proteins/drug effects , tau Proteins/metabolism , Aged , Aged, 80 and over , Alzheimer Disease/pathology , Amyloid beta-Peptides/toxicity , Animals , Calmodulin-Binding Proteins/pharmacology , Cell Count , Cerebral Cortex/cytology , Cricetinae , Cricetulus , Embryo, Mammalian , Enzyme Inhibitors/pharmacology , Glutamic Acid/pharmacology , Green Fluorescent Proteins/genetics , Humans , In Situ Nick-End Labeling/methods , Molecular Weight , Mutation/genetics , Neurons/drug effects , Neurons/metabolism , Peptide Fragments/toxicity , Peptides/metabolism , Peptides/pharmacology , Phosphorylation/drug effects , Rats , Thapsigargin/pharmacology , Transfection/methods , tau Proteins/genetics
9.
J Am Soc Nephrol ; 22(3): 508-17, 2011 Mar.
Article in English | MEDLINE | ID: mdl-21164023

ABSTRACT

The thiazide-sensitive NaCl cotransporter (NCC) plays a key role in renal salt reabsorption and the determination of systemic BP, but the molecular mechanisms governing the regulation of NCC are not completely understood. Here, through pull-down experiments coupled to mass spectrometry, we found that γ-adducin interacts with the NCC transporter. γ-Adducin colocalized with NCC to the distal convoluted tubule. (22)Na(+) uptake experiments in the Xenopus laevis oocyte showed that γ-adducin stimulated NCC activity in a dose-dependent manner, an effect that occurred upstream from With No Lysine (WNK) 4 kinase. The binding site of γ-adducin mapped to the N terminus of NCC and encompassed three previously reported phosphorylation sites. Supporting this site of interaction, competition with the N-terminal domain of NCC abolished the stimulatory effect of γ-adducin on the transporter. γ-Adducin failed to increase NCC activity when these phosphorylation sites were constitutively inactive or active. In addition, γ-adducin bound only to the dephosphorylated N terminus of NCC. Taken together, our observations suggest that γ-adducin dynamically regulates NCC, likely by amending the phosphorylation state, and consequently the activity, of the transporter. These data suggest that γ-adducin may influence BP homeostasis by modulating renal NaCl transport.


Subject(s)
Blood Pressure/physiology , Calmodulin-Binding Proteins/metabolism , Kidney Tubules, Distal/metabolism , Sodium Chloride Symporters/metabolism , Absorption/physiology , Animals , Calmodulin-Binding Proteins/pharmacology , Dose-Response Relationship, Drug , Female , Humans , Kidney Tubules, Distal/cytology , Models, Animal , Oocytes/cytology , Oocytes/drug effects , Oocytes/metabolism , Phosphorylation , Sodium Chloride/metabolism , Xenopus laevis
10.
Biophys J ; 99(6): 1861-8, 2010 Sep 22.
Article in English | MEDLINE | ID: mdl-20858431

ABSTRACT

Caldesmon is an actin- and myosin-binding protein found in smooth muscle that inhibits actin activation of myosin ATPase activity. The activity of caldesmon is controlled by phosphorylation and by binding to Ca(2+)-calmodulin. We investigated the effects of phosphorylation by p(21)-activated kinase 3 (PAK) and calmodulin on the 22 kDa C-terminal fragment of caldesmon (CaD22). We substituted the major PAK sites, Ser-672 and Ser-702, with either alanine or aspartic acid to mimic nonphosphorylated and constitutively phosphorylated states of caldesmon, respectively. The aspartic acid mutation of CaD22 weakened Ca(2+)-calmodulin binding but had no effect on inhibition of ATPase activity. Phosphorylation of the aspartic acid mutant with PAK resulted in the slow phosphorylation of Thr-627, Ser-631, Ser-635, and Ser-642. Phosphorylation at these sites weakened Ca(2+)-calmodulin binding further and reduced the inhibitory activity of CaD22 in the absence of Ca(2+)-calmodulin. Phosphorylation of these sites of the alanine mutant of CaD22 had no effect on Ca(2+)-calmodulin binding but did reduce inhibition of ATPase activity. Thus, the region between residues 627 and 642 may contribute to the overall regulation of caldesmon's activity.


Subject(s)
Calcium/metabolism , Calmodulin-Binding Proteins/chemistry , Calmodulin-Binding Proteins/metabolism , Calmodulin/metabolism , Enzyme Inhibitors/chemistry , Enzyme Inhibitors/metabolism , Adenosine Triphosphatases/antagonists & inhibitors , Amino Acid Sequence , Amino Acid Substitution , Animals , Calmodulin-Binding Proteins/genetics , Calmodulin-Binding Proteins/pharmacology , Chickens , Enzyme Inhibitors/pharmacology , Molecular Sequence Data , Phosphorylation/genetics , Protein Binding , Rabbits
11.
Hum Genet ; 128(2): 137-43, 2010 Aug.
Article in English | MEDLINE | ID: mdl-20473689

ABSTRACT

A large proportion of the phenotypic variation in blood pressure (BP) appears to be inherited as a polygenic trait. This study examined the association between 12 single nucleotide polymorphisms (SNPs) in the guanine nucleotide binding protein beta polypeptide 3 (GNB3) and adducin 1 alpha (ADD1) genes and systolic (SBP), diastolic (DBP), and mean arterial (MAP) BP. A total of 3,142 individuals from 636 families were recruited from rural north China, and 2,746 met the eligibility criteria for analysis. BP measurements were obtained using a random-zero sphygmomanometer. Genetic variants were determined using SNPlex assays on an automated DNA Sequencer. A mixed linear model was used to estimate the association between each SNP and BP level. After Bonferroni correction, marker rs4963516 of the GNB3 gene remained significantly associated with DBP (corrected P values = 0.006, 0.007 and 0.002 for co-dominant, additive, and recessive models, respectively) and MAP (corrected P values = 0.02, 0.049, and 0.005, respectively). Compared to carriers of the major A allele, CC homozygotes had higher mean DBP (75.81 +/- 0.62 vs. 73.46 +/- 0.25 mmHg, P = 0.0002) and MAP (91.87 +/- 0.68 vs. 89.42 +/- 0.28 mmHg, P = 0.0004) after adjusting for covariates of age, gender, BMI, study site, and room temperature during BP measurement. In summary, these data support a role for the GNB3 gene in BP regulation in the Chinese population. Future studies aimed at replicating these novel findings are warranted.


Subject(s)
Asian People/genetics , Blood Pressure/genetics , Calmodulin-Binding Proteins/genetics , Polymorphism, Single Nucleotide , Alleles , Arteries , Blood Pressure/drug effects , Calmodulin-Binding Proteins/pharmacology , China , Female , Heterotrimeric GTP-Binding Proteins , Humans , Hypotension/genetics , Male , Middle Aged , Polymorphism, Genetic , Population Groups
12.
Neurodegener Dis ; 7(1-3): 56-9, 2010.
Article in English | MEDLINE | ID: mdl-20160460

ABSTRACT

BACKGROUND: Alzheimer's disease (AD) is the most prevalent form of dementia predominantly affecting the elderly. It is believed that soluble amyloid-beta (Abeta) oligomers are involved in the pathogenesis of AD, yet the underlying mechanisms remain elusive. OBJECTIVES: Emerging evidence suggests that mitochondrial dysfunction likely plays a critical role in Abeta-induced neuronal degeneration. Previously, we demonstrated that Abeta-derived diffusible ligands (ADDLs) induce reduced mitochondrial density in neurites, and we suspect that an impaired mitochondrial trafficking might be involved, which is tested in this study. METHODS: Using live cell imaging, anterograde and retrograde transport of mitochondria in primary hippocampal neurons treated with sub-lethal doses of ADDLs was measured. RESULTS: We found that ADDLs induced significant impairment in both anterograde and retrograde transport of mitochondria along axons. CONCLUSION: These results suggest that an impaired mitochondrial transport likely contributes to ADDL-induced abnormal mitochondrial distribution and dysfunction and also reinforce the idea that axonal transport is likely involved in AD pathogenesis.


Subject(s)
Axonal Transport/drug effects , Calmodulin-Binding Proteins/pharmacology , Mitochondria/drug effects , Neurons/cytology , Amyloid beta-Peptides/pharmacology , Animals , Axonal Transport/physiology , Cells, Cultured , Embryo, Mammalian , Hippocampus/cytology , Humans , Luminescent Proteins/genetics , Mitochondria/metabolism , Neurons/drug effects , Rats , Transfection/methods
13.
J Biol Chem ; 285(1): 71-9, 2010 Jan 01.
Article in English | MEDLINE | ID: mdl-19889635

ABSTRACT

The actin-binding protein caldesmon (CaD) reversibly inhibits smooth muscle contraction. In non-muscle cells, a shorter CaD isoform co-exists with microfilaments in the stress fibers at the quiescent state, but the phosphorylated CaD is found at the leading edge of migrating cells where dynamic actin filament remodeling occurs. We have studied the effect of a C-terminal fragment of CaD (H32K) on the kinetics of the in vitro actin polymerization by monitoring the fluorescence of pyrene-labeled actin. Addition of H32K or its phosphorylated form either attenuated or accelerated the pyrene emission enhancement, depending on whether it was added at the early or the late phase of actin polymerization. However, the CaD fragment had no effect on the yield of sedimentable actin, nor did it affect the actin ATPase activity. Our findings can be explained by a model in which nascent actin filaments undergo a maturation process that involves at least two intermediate conformational states. If present at early stages of actin polymerization, CaD stabilizes one of the intermediate states and blocks the subsequent filament maturation. Addition of CaD at a later phase accelerates F-actin formation. The fact that CaD is capable of inhibiting actin filament maturation provides a novel function for CaD and suggests an active role in the dynamic reorganization of the actin cytoskeleton.


Subject(s)
Actins/chemistry , Actins/metabolism , Calmodulin-Binding Proteins/metabolism , Animals , Calmodulin/metabolism , Calmodulin-Binding Proteins/pharmacology , Computer Simulation , Extracellular Signal-Regulated MAP Kinases/metabolism , Fluorescence , Humans , Kinetics , Peptide Fragments/pharmacology , Phosphorylation/drug effects , Protein Conformation/drug effects , Pyrenes/metabolism , Rabbits , Software , Time Factors
14.
Exp Eye Res ; 88(4): 713-7, 2009 Apr.
Article in English | MEDLINE | ID: mdl-18793636

ABSTRACT

Abnormally high resistance to aqueous humor drainage via the trabecular meshwork and Schlemm's canal is highly correlated with the development of primary open-angle glaucoma. Contractility of the actomyosin system in the trabecular cells or inner wall endothelium of Schlemm's canal is an important factor in the regulation of outflow resistance. Cytoskeletal agents, affecting F-actin integrity or actomyosin contractility, or gene therapies, employing overexpression of caldesmon or Rho-A inhibition, can decrease outflow resistance in the drainage pathway. In this review, we discuss the mechanisms underlying these and similar effects on trabecular outflow resistance in living animals and/or in cultured ocular anterior segments from enucleated animal or human eyes.


Subject(s)
Actomyosin/physiology , Trabecular Meshwork/physiology , Animals , Calmodulin-Binding Proteins/pharmacology , Glaucoma, Open-Angle/physiopathology , Humans , Intraocular Pressure/drug effects , Intraocular Pressure/physiology , Protein Kinase Inhibitors/pharmacology , Trabecular Meshwork/drug effects , Trabecular Meshwork/ultrastructure , Tubulin Modulators/pharmacology
15.
Urology ; 73(5): 1126-30, 2009 May.
Article in English | MEDLINE | ID: mdl-18455776

ABSTRACT

OBJECTIVES: To detect the effect of ischemia/reperfusion (I/R) injury on rabbit bladder, using physiological study and immunoblotting techniques. METHODS: Twelve male New Zealand White rabbits were separated into three groups of 4 rabbits each. Group 1 served as control. Group 2 rabbits (ischemia-alone group) underwent in vitro bilateral ischemia surgery for 2 hours. In group 3 (I/R group), bilateral ischemia was similarly induced, and the rabbits were allowed to recover for 2 weeks. The contractile responses to electrical field stimulation, adenosine triphosphate, carbachol, and KCl were recorded. Expression levels of the signaling targets, Rho-kinase (ROK), protein kinase C potentiated inhibitor (CPI-17), caldesmon (CaD), and calponin (CaP) were analyzed by Western blotting. RESULTS: Ischemia alone resulted in significant reductions in the contractile responses, whereas I/R resulted in further decreases after all forms of stimulation. In muscle layer, ROK expression increased immediately after ischemia and recovered to the control level after 2 weeks' recovery. However, in mucosa layer, ROK expression showed no significant change after ischemia but significantly increased after reperfusion. After ischemic damage, CPI-17, the functional protein involved in smooth-muscle Ca(2+) sensitization, was significantly increased and then decreased after 2 weeks of reperfusion. The expression of CaP significantly increased after ischemia and decreased after reperfusion. Levels of high-molecular-weight CaD significantly decreased after ischemia and remained very low after reperfusion. CONCLUSIONS: This study provides further understanding of the role of regulatory proteins in detrusor muscle after ischemia and I/R-induced contractile dysfunction.


Subject(s)
Contractile Proteins/metabolism , Ischemia/enzymology , Muscle, Smooth/physiology , Reperfusion Injury/enzymology , Urinary Bladder/physiopathology , rho-Associated Kinases/metabolism , Animals , Blotting, Western , Calmodulin-Binding Proteins/pharmacology , Carbachol/pharmacology , Contractile Proteins/drug effects , Disease Models, Animal , Electrophoresis, Polyacrylamide Gel , Ischemia/physiopathology , Male , Muscle, Smooth/drug effects , Probability , Rabbits , Random Allocation , Regulatory Sequences, Ribonucleic Acid/drug effects , Regulatory Sequences, Ribonucleic Acid/physiology , Reperfusion Injury/physiopathology , Sensitivity and Specificity , Urinary Bladder/injuries
16.
Mini Rev Med Chem ; 8(12): 1209-13, 2008 Oct.
Article in English | MEDLINE | ID: mdl-18855735

ABSTRACT

Caldesmon is a negative regulator of cell proliferation, migration, and metalloproteinase release. Caldesmon function is regulated by multiple kinases, targeting multiple phosphorylation sites. Recently, overexpression of caldesmon has been shown to inhibit neointimal formation after experimental angioplasty, suggesting that caldesmon may be a potential therapeutic target for proliferative vascular diseases.


Subject(s)
Calmodulin-Binding Proteins/pharmacology , Vascular Diseases/drug therapy , Actins/metabolism , Angioplasty , Animals , Cell Movement , Cell Proliferation , Coronary Restenosis , Gene Transfer Techniques , Humans , Metalloproteases/metabolism , Models, Biological , Phosphorylation
17.
Free Radic Biol Med ; 44(9): 1732-51, 2008 May 01.
Article in English | MEDLINE | ID: mdl-18325348

ABSTRACT

The role of TGF-beta1 in hydrogen peroxide-induced senescence-like morphogenesis has been described. The aim of this work was to investigate whether TGF-beta1-independent changes in protein synthesis are involved in this morphogenesis and to study possible mechanisms occurring earlier than TGF-beta1 overexpression. Among the multiple TGF-beta1-independent changes in protein neosynthesis, followed or not by posttranslational modifications, identified by proteomic analysis herein, those of ezrin, L-caldesmon, and HSP27 were particularly studied. Rho-GTPase cdc42 was shown to be responsible for p38(MAPK) activation, in turn triggering phosphorylation of L-caldesmon and HSP27. Cdc42 was also shown to be mainly responsible for the increase in TGF-beta1 mRNA level observed at 24 h after treatment with H(2)O(2) and onward. This study further clarified the mechanisms of senescence-like morphogenesis in addition to the previously demonstrated role of TGF-beta1 signaling pathways.


Subject(s)
Fibroblasts/metabolism , Hydrogen Peroxide/pharmacology , Transforming Growth Factor beta1/metabolism , cdc42 GTP-Binding Protein/metabolism , p38 Mitogen-Activated Protein Kinases/metabolism , Calmodulin-Binding Proteins/pharmacology , Cell Survival , Cellular Senescence , Electrophoresis, Gel, Two-Dimensional , Free Radicals , Humans , Hydrogen Peroxide/chemistry , Models, Biological , Oxidative Stress , Phenotype , Phosphorylation
18.
J Neurophysiol ; 97(3): 2465-79, 2007 Mar.
Article in English | MEDLINE | ID: mdl-17353554

ABSTRACT

The translation of prior activity into changes in excitability is essential for memory and the initiation of behavior. After brief synaptic input, the bag cell neurons of Aplysia californica undergo a nearly 30-min afterdischarge to release egg-laying hormone. The present study examines a prolonged depolarization in cultured bag cell neurons. A 5-Hz, 10-s action potential train elicited a depolarization of about 10 mV, which lasted

Subject(s)
Aplysia/cytology , Ion Channels/physiology , Membrane Potentials/physiology , Neurons/physiology , 1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine/analogs & derivatives , 1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine/pharmacology , Animals , Calmodulin-Binding Proteins/pharmacology , Cations/metabolism , Cells, Cultured , Chelating Agents/pharmacology , Dose-Response Relationship, Drug , Dose-Response Relationship, Radiation , Egtazic Acid/pharmacology , Electric Stimulation/methods , Enzyme Inhibitors/pharmacology , Ion Channels/drug effects , Ion Channels/radiation effects , Membrane Potentials/drug effects , Membrane Potentials/radiation effects , Membrane Transport Modulators/pharmacology , Neurons/drug effects , Neurons/radiation effects , Patch-Clamp Techniques , Potassium Channel Blockers/pharmacology , Tetraethylammonium/pharmacology , Time Factors
19.
Tsitologiia ; 48(7): 554-9, 2006.
Article in Russian | MEDLINE | ID: mdl-17087146

ABSTRACT

The effect of caldesmon (CaD) on conformational changes in F-actin modified by fluorescent probe TRITC-phalloidin was investigated by polarized fluorimetry. Changes were induced by a subfragment-1 (S-1) of myosin in the absence or presence of CaD in ghost muscle fibers obtained from intact and denervated slow (SOL) and fast (EDL) skeletal muscles of rats. S-1 binding to actin of both SOL and EDL muscles was shown to cause changes in polarized parameters of TRITC-phalloidin typical for a strong actin-myosin binding as well as of transition ofactin subunits from "off" to "on" state. CaD inhibits this significantly. Denervation atrophy inhibits the effect of S-1 as well but does not affect the capability of CaD decreasing the formation of strong binding in actomyosin complex. It is supposed that CaD "freezes" F-actin structure in "off" state. The denervation atrophy has no effect on CaD responsibility to bind thin filaments and to switch "off" actin monomers.


Subject(s)
Actins/metabolism , Calmodulin-Binding Proteins/physiology , Muscle, Skeletal/physiology , Myosins/metabolism , Actins/chemistry , Animals , Calmodulin-Binding Proteins/chemistry , Calmodulin-Binding Proteins/isolation & purification , Calmodulin-Binding Proteins/pharmacology , Male , Muscle Contraction , Muscle Denervation , Muscle, Skeletal/innervation , Myosin Subfragments/isolation & purification , Myosin Subfragments/metabolism , Myosin Subfragments/physiology , Protein Binding , Protein Conformation/drug effects , Rats , Rats, Wistar , Time Factors
20.
Arterioscler Thromb Vasc Biol ; 26(10): 2231-7, 2006 Oct.
Article in English | MEDLINE | ID: mdl-16888241

ABSTRACT

OBJECTIVE: Light-type caldesmon (l-CaD) is a potent cytostatic and antiangiogenic protein that regulates cell growth and survival via modulation of the cell shape and cytoskeleton. The aim of this study is to explore the potential value of l-CaD for use as a cytostatic agent to inhibit neointimal formation after angioplasty by suppressing vascular smooth muscle cell (VSMC) growth and migration. METHODS AND RESULTS: We tested the cytostatic function of l-CaD in cultured VSMCs using assays for apoptosis, cell proliferation, and migration, and evaluated the expression pattern of relevant signaling proteins (focal adhesion kinase [FAK] and mitogen-activated protein kinases) in VSMCs. Transfection of adenoviral vector encoding l-CaD (Ad-l-CaD) resulted in progressive loss of actin stress fibers and cell retraction. Enzyme-linked immunosorbent assay demonstrated that Ad-l-CaD transfection increased the apoptosis rate by 75% and reduced BrdU uptake by 49%. Furthermore, transfection of Ad-l-CaD inhibited migration of VSMCs induced by platelet-derived growth factor-BB (PDGF) by 36% (P<0.05). Immunoblotting analysis revealed that l-CaD overexpression reduced PDGF-induced phosphorylation of both FAK and extracellular signal regulated-kinase (ERK). In balloon-injured rat carotid arteries, Ad-l-CaD transfection inhibited neointimal formation by 37% (P<0.05) without delaying re-endothelialization at 14 days. CONCLUSIONS: Overexpression of l-CaD suppressed cell growth and survival in VSMCs and inhibited neointimal formation after experimental angioplasty, partly by regulating the cytoskeletal tension-FAK-ERK axis.


Subject(s)
Angioplasty , Calmodulin-Binding Proteins/pharmacology , Cell Movement/drug effects , Cell Proliferation/drug effects , Muscle, Smooth, Vascular/cytology , Myocytes, Smooth Muscle/cytology , Myocytes, Smooth Muscle/physiology , Tunica Intima/growth & development , Animals , Apoptosis/drug effects , Carotid Artery Injuries/etiology , Carotid Artery Injuries/physiopathology , Catheterization , Cell Shape/drug effects , Cell Survival/drug effects , Cells, Cultured , Cytoskeleton/drug effects , Endothelial Cells/cytology , Extracellular Signal-Regulated MAP Kinases/metabolism , Focal Adhesion Protein-Tyrosine Kinases/metabolism , Humans , Immunoblotting , Muscle, Smooth, Vascular/enzymology , Myocytes, Smooth Muscle/enzymology , Paclitaxel/pharmacology , Protein Isoforms/pharmacology , Rats
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