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1.
Braz. j. biol ; 81(3): 684-691, July-Sept. 2021. graf
Article in English | LILACS | ID: biblio-1153408

ABSTRACT

Abstract Plants adjust their shoot growth to acclimate to changing environmental factors, such as to enhanced Ultraviolet-B (UV-B) radiation. However, people have ignored that plant roots can also respond to UV-B light. Here, we find the morphology curled wheat roots under UV-B radiation, that we call, "bending roots." The curly region is the transition zone of the root after observed at the cellular level. After exposed to enhanced UV-B radiation for 2 d (10.08 KJ/m2/d), cell size decreased and actin filaments gathered in wheat roots. We also find that H2O2 production increased and that content of the indole-3-acetic acid (IAA) increased remarkably. The pharmacological experiment revealed that actin filaments gathered and polymerized into bundles in the wheat root cells after irrigated H2O2 and IAA. These results indicated that actin filaments changed their distribution and formed the "bending root," which was related to H2O2 production and increase in IAA. Overall, actin filaments in wheat root cells could be a subcellular target of UV-B radiation, and its disruption determines root morphology.


Resumo As plantas ajustam o crescimento da parte aérea para se adaptarem a fatores ambientais variáveis, como o aumento da radiação ultravioleta B (UVB). No entanto, as pessoas ignoram que as raízes das plantas também podem responder à luz UVB. Neste estudo, verificamos a morfologia das raízes enroladas de trigo sob radiação UVB, o que chamamos de "raízes dobradas". A região encaracolada é a zona de transição da raiz no nível celular. Depois de exposição à radiação UVB aprimorada por 2 dias (10,08 KJ/m2/d), o tamanho das células diminuiu, e os filamentos de actina se reuniram. Também constatamos que a produção de H2O2 aumentou e que o conteúdo do ácido indol-3-acético (IAA) aumentou notavelmente. O experimento farmacológico revelou que os filamentos de actina se reuniram e polimerizaram em feixes nas células da raiz de trigo após irrigação com H2O2 e IAA. Esses resultados indicam que os filamentos de actina alteraram sua distribuição e formaram a "raiz dobrada", relacionada à produção de H2O2 e ao aumento do IAA. No geral, os filamentos de actina nas células da raiz de trigo podem ser um alvo subcelular da radiação UVB, e sua interrupção determina a morfologia da raiz.


Subject(s)
Triticum , Hydrogen Peroxide , Ultraviolet Rays , Actin Cytoskeleton , Plant Roots
2.
J. venom. anim. toxins incl. trop. dis ; 27: e20200106, 2021. tab, graf, ilus
Article in English | LILACS, VETINDEX | ID: biblio-1154774

ABSTRACT

Avian pathogenic Escherichia coli (APEC) isolated from avian cellulitis lesions produces a toxin, named Escherichia coli vacuolating factor (ECVF), that causes cell vacuolization and induces inflammatory response in broiler chicken. Methods We investigated the intracellular activities of ECVF in avian fibroblasts using fluorescence staining, electron microscopy, MTT and LDH measurements. As ECVF act specifically in avian cells, we performed blotting assay followed by mass spectrometry to better understand its initial intracellular protein recognition. Results ECVF induced actin contraction, mitochondrial damage and membrane permeability alterations. Ultrastructural analysis showed intracellular alterations, as nuclear lobulation and the presence of degraded structures inside the vacuoles. Moreover, ECVF induced cell death in fibroblasts. ECVF-biotin associates to at least two proteins only in avian cell lysates: alpha-actinin 4 and vinculin, both involved in cytoskeleton structure. Conclusion These findings demonstrated that ECVF plays an important role in avian cellulitis, markedly in initial steps of infection. Taken together, the results place this toxin as a target for drug and/or vaccine development, instead of the use of large amounts antibiotics.(AU)


Subject(s)
Animals , Vacuoles , Actin Cytoskeleton , Chickens , Actins , Escherichia coli , Fibroblasts , Cellulitis
3.
Int. j. morphol ; 38(5): 1513-1518, oct. 2020.
Article in Spanish | LILACS | ID: biblio-1134469

ABSTRACT

RESUMEN: El trastorno del espectro autista (TEA) abarca un grupo de trastornos multifactoriales del neurodesarrollo caracterizados por una comunicación e interacción social deteriorada y por comportamientos repetitivos y estereotipados. Múltiples estudios han revelado que en el TEA existen disfunciones sinápticas, en la cual la morfología y función neuronal son sustratos importantes en esta patogenia. En esta revisión comentamos los datos disponibles a nivel de anormalidades neuronales en el TEA, enfatizando la morfología de las dendritas, espinas dendríticas y citoesquelo de actina. Las dendritas y espinas dendríticas, ricas en actina, forman la parte postsináptica de la mayoría de las sinapsis excitadoras. En el TEA, los datos obtenidos apuntan a una desregulación en el crecimiento y desarrollo dendrítico, así como una alteración en la densidad de las espinas dendríticas. Lo anterior, se ve acompañado de alteraciones en la remodelación y composición del citoesqueleto neuronal. Para comprender mejor la fisiopatología del TEA, es necesario mayor información sobre cómo los cambios morfofuncionales de los actores que participan en la sinapsis impactan en los circuitos y el comportamiento.


SUMMARY: Autism Spectrum Disorder (ASD) is a group of multifactorial neurodevelopmental disorders, characterized by impaired communication and social interaction skills, and by repetitive and stereotyped behaviors. Multiple studies report that there are synaptic dysfunctions in ASD, in which important substrates such as morphology and neuronal function are involved in this pathogenesis. In this review we discuss the data available at the level of neuronal abnormalities in ASD, and emphasize the morphological aspects of dendrites, dendritic spines, and actin cytoskeleton. Actin-rich dendrites and dendritic spines shape the postsynaptic part of the most excitatory synapses. In ASD, the data points to a dysregulation in dendritic growth and development, as well as an alteration in the density of dendritic spines. This is accompanied by alterations in the remodeling and composition of the neuronal cytoskeleton. In order to better understand the pathophysiology of ASD, further information is needed on how the elements of synaptic morphofunctional changes impact circuits and behavior.


Subject(s)
Humans , Dendrites/pathology , Autism Spectrum Disorder/pathology , Actin Cytoskeleton/pathology , Dendritic Spines/pathology , Autism Spectrum Disorder/physiopathology
5.
Article in English | WPRIM | ID: wpr-742389

ABSTRACT

BACKGROUND: Three-dimensional (3D) printing with a direct metal fabrication (DMF) technology has been innovatively introduced in the field of surface treatment of prostheses. The purpose of this study was to determine whether such modifications on the surface of cobalt-chromium (CoCr) alloy by titanium powder coating using DMF improves the osseointegration ability of CoCr alloy. METHODS: We compared the in vitro and in vivo ability of cells to adhere to DMF-coated CoCr alloy with machining. Biological and morphological responses to human osteoblast cell lines were examined by measuring cell proliferation rate and observing expression of actin filament. For in vivo study, we inserted different specimens in each medulla of the distal femurs of rabbit. After 3 months, the distal femurs were harvested, and a push-out test and histomorphometric analyses were performed. RESULTS: The cell proliferation rate and cell adhesion in the DMF group were higher compared with those in the machined group. Human osteoblast cells on the DMF-coated surface were more strongly adhered and well-proliferated compared with those on the other surface. In the in vivo test, there was a significant difference in the ultimate shear strength between the DMF and machined groups (2.49 MPa vs. 0.87 MPa, respectively, p = 0.001). In the histomorphometric analysis, there was a significant difference in the mean bone-to-implant contact percentages between the DMF and machined groups (72.3 ± 6.2% vs. 47.6 ± 6.9%, respectively, p < 0.001). CONCLUSION: Titanium coating of CoCr alloy with 3D metal printing provides optimal surface characteristics and a good biological surface both in vitro and in vivo.


Subject(s)
Actin Cytoskeleton , Alloys , Cell Adhesion , Cell Line , Cell Proliferation , Femur , Humans , In Vitro Techniques , Osseointegration , Osteoblasts , Printing, Three-Dimensional , Prostheses and Implants , Shear Strength , Titanium
6.
Article in Korean | WPRIM | ID: wpr-762189

ABSTRACT

Filamin A is an actin-binding protein and, in humans, is encoded by FLNA gene in the long arm of X chromosome. Filamin A plays a role in the formation of cytoskeleton by crosslinking actin filaments in cytoplasm. FLNA mutations affect cytoskeletal regulatory processes and cellular migrating abnormalities that result in periventricular heterotopia. A 5-month-old girl was hospitalized because of breathing difficulty and was diagnosed as having periventricular heterotopia with laryngomalacia, cricopharyngeal incoordination, pulmonary hypertension, and chronic lung disease. A genetic test was performed to find the cause of periventricular heterotopia, and FLNA gene mutation (c.5998+1G>A) was confirmed for the first time in Korea. After discharge, she developed respiratory failure due to a viral infection at 8 months of her age. In spite of management with mechanical ventilation, she died of pneumothorax and pulmonary hemorrhage. Herein, we report a case of FLNA gene mutation who presented with periventricular nodular heterotopia with respiratory insufficiency.


Subject(s)
Actin Cytoskeleton , Arm , Ataxia , Cytoplasm , Cytoskeleton , Female , Filamins , Hemorrhage , Humans , Hypertension, Pulmonary , Infant , Korea , Laryngomalacia , Lung Diseases , Periventricular Nodular Heterotopia , Pneumothorax , Respiration , Respiration, Artificial , Respiratory Insufficiency , X Chromosome
7.
Article in English | WPRIM | ID: wpr-761893

ABSTRACT

BACKGROUND: Nano-hydroxyapatite/polyamide 66 (nHA/PA66) is a composite used widely in the repair of bone defects. However, this material is insufficient bioactivity. In contrast, D-RADA16-RGD self-assembling peptide (D-RADA16-RGD sequence containing all D-amino acids is Ac-RADARADARADARADARGDS-CONH2) shows admirable bioactivity for both cell culture and bone regeneration. Here, we describe the fabrication of a favorable biomaterial material (nHA/PA66/D-RADA16-RGD). METHODS: Proteinase K and circular dichroism spectroscopy were employed to test the stability and secondary structural properties of peptide D-RADA16-RGD respectively. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to characterize the surface of these materials. Confocal laser scanning (CLS), cell counting kit-8 tests (CCK-8), alizarin red S staining, cell immunofluorescence analysis and Western blotting were involved in vitro. Also biosafety and bioactivity of them have been evaluated in vivo. RESULTS: Proteinase K and circular dichroism spectroscopy demonstrated that D-RADA16-RGD in nHA/PA66 was able to form stable-sheet secondary structure. SEM and TEM showed that the D-RADA16-RGD material was 7–33 nm in width and 130–600 nm in length, and the interwoven pore size ranged from 40 to 200 nm. CLS suggests that cells in nHA/PA66/D-RADA16-RGD group were linked to adjacent cells with more actin filaments. CCK-8 analysis showed that nHA/PA66/D-RADA16-RGD revealed good biocompatibility. The results of Alizarin-red S staining and Western blotting as well as vivo osteogenesis suggest nHA/PA66/D-RADA16-RGD exhibits better bioactivity. CONCLUSION: This study demonstrates that our nHA/PA66/D-RADA16-RGD composite exhibits reasonable mechanical properties, biocompatibility and bioactivity with promotion of bone formation.


Subject(s)
Actin Cytoskeleton , Blotting, Western , Bone Regeneration , Cell Count , Cell Culture Techniques , Circular Dichroism , Endopeptidase K , Fluorescent Antibody Technique , In Vitro Techniques , Microscopy, Electron, Scanning , Microscopy, Electron, Transmission , Osteogenesis , Sincalide , Spectrum Analysis
8.
Article in English | WPRIM | ID: wpr-785579

ABSTRACT

Steroid-resistant nephrotic syndrome (SRNS) has long been a challenge for clinicians due to its poor responsiveness to immunosuppressants, and rapid progression to end-stage renal disease. Identifying a monogenic cause for SRNS may lead to a better understanding of podocyte structure and function in the glomerular filtration barrier. This review focuses on genes associated with slit diaphragm, actin cytoskeleton, transcription factors, nucleus, glomerular basement membrane, mitochondria, and other proteins that affect podocyte biology.


Subject(s)
Actin Cytoskeleton , Biology , Diaphragm , Glomerular Basement Membrane , Glomerular Filtration Barrier , Immunosuppressive Agents , Kidney Failure, Chronic , Mitochondria , Nephrotic Syndrome , Podocytes , Proteinuria , Transcription Factors
9.
Article in Chinese | WPRIM | ID: wpr-781371

ABSTRACT

OBJECTIVE@#To analyze the expression and clinical significance of long non-coding RNA (lncRNA) actin filament-associated protein 1-antisense RNA1 (AFAP1-AS1) in oral squamous cell carcinoma (OSCC) and its effect on the biobehavior of OSCC cells.@*METHODS@#Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the expression of lncRNA AFAP1-AS1 in the tumor tissue and matching adjacent normal tissue of OSCC patients (n=55), SCC25 cells, and normal oral keratinocyte lines (NOK) cells. The correlation between AFAP1-AS1 expression and the clinicopathological characteristics of OSCC patients was analyzed. The relationship between AFAP1-AS1 and prognosis was also studied with the Kaplan-Meier method. AFAP1-AS1 siRNA was transfected into the SCC25 cells. Cell counting kit-8 (CCK-8) and Trans-well were used to detect cell proliferation, invasion, and migration. The expression of the invasion-associated protein, AFAP1, and Rho GTPase family members, was detected by Western blot. In addition, the immunofluorescence of the cytoskeletal actin filament was observed.@*RESULTS@#The expression of AFAP1-AS1 was higher in the OSCC tissues than in the NOK cells, and the relative expression of AFAP1-AS1 was higher in the SCC25 cells than in the NOK cells (P<0.001). AFAP1-AS1 expression was associated with the degree of diffe-rentiation, TNM stage, lymphatic metastasis, and poor prognosis of OSCC (P<0.05). Patients with a high expression of AFAP1-AS1 had lower survival rates than those with a low expression of AFAP1-AS1 (P<0.05). After transfected by AFAP1-AS1 siRNA, the expression of AFAP1-AS1 was downregulated. The inhibition of AFAP1-AS1 expression consequently suppressed the proliferation, invasion, and migration of SCC25. Moreover, AFAP1-AS1 siRNA upregulated the expression levels of AFAP1, RhoA, Rac2, Rab10, RhoGDI, and Pfn1 but downregulated the expression of RhoC. Immunofluorescence showed that AFAP1-AS1 also reduced the formation of stress filaments in the cytoskeleton and affected the integrity of the actin fila-ment.@*CONCLUSIONS@#The expression of AFAP1-AS1 was high in the OSCC tissues and SCC25 cells and is associated with the development and prognosis of OSCC. The knockdown of AFAP1-AS1 might inhibit the proliferation and invasion of OSCC cells by regulating the integrity of the actin filament.


Subject(s)
Actin Cytoskeleton , Carcinoma, Squamous Cell , Cell Line, Tumor , Cell Proliferation , Gene Expression Regulation, Neoplastic , Humans , Mouth Neoplasms , RNA, Bacterial , RNA, Long Noncoding
10.
São Paulo; s.n; s.n; 2019. 85 p. tab, graf.
Thesis in English | LILACS | ID: biblio-1007407

ABSTRACT

Gliomas are the most common form of primary intracranial malignancy, among which astrocytomas are the most frequent. Ectodermal-cortex protein 1 (ENC 1), also known as Nuclear Restricted Protein/Brain (NRP/B), was first characterized as a protein which interacts with the cytoskeleton by binding to actin through Kelch-like domains, being related to neural fate specification during development of the nervous system. The first chapter of this thesis confirms ENC1 as a tumor suppression properties by a genomic edition approach, analyses ENC1 expression in a set of patient glioma samples and describes the correlation these data with patients survival and progression-free survival, concluding that ENC1 expression may constitute a biomarker for glioma aggressiveness. The second chapter refers to the identification and in vitro characterization of the LHTNELQ peptide, which was selected by the Phage Display method using human glioblastoma cells. This new peptide is able to be internalized by these cells and features as a new tool for the development of glioma therapeutics. The third chapter report an alternative method to generate growth curves of adherent cell cultures, which is based on the CFSE fluorescence decay over time. It is an alternative method to determine growth curves of cultured cells, with smaller variation among technical replicates than that of counting-based methods


Gliomas são a forma mais comum de malignidades primárias intracranianas, dentre os quais os astrocitomas são os mais frequentes. A proteína Ectodermal-neural cortex 1 (ENC1), também conhecida como Nuclear Restricted Protein/Brain (NRP/B), foi primeiramente caracterizada como uma proteína que interage com o citoesqueleto por meio de ligação à actina através de domínios Kelch-like, sendo relacionada com diferenciação neuronal durante o desenvolvimento do sistema nervoso. O primeiro capítulo desta tese descreve confirmação da capacidade supressora tumoral de ENC1 por abordagem de edição genômica, analisa a expressão de ENC1 em um conjunto de amostras de pacientes com gliomas e correlaciona esses dados com tempo de sobrevida geral e sobrevida livre de progressão tumoral nos pacientes, concluindo que a expressão de ENC1 pode ser utilizada como um biomarcador da agressividade do glioma. O segundo capítulo apresenta a identificação e caracterização in vitro do peptídeo LHTNELQ, que foi selecionado pela metodologia de Phage display utilizandose de células de glioblastoma humano. Este novo peptídeo é capaz de internalizar-se nestas células e figura como uma nova ferramenta para o desenvolvimento de estratégias terapêuticas para glioblastomas. No terceiro capítulo propõe-se um método alternativo para gerar curvas de crescimento celular de cultura aderente, o qual é baseado no decaimento da fluorescência do reagente CFSE ao longo do tempo. Tratase de um método alternativo para a determinação de curvas de crescimento de culturas aderentes, com menor variação entre as réplicas técnicas do que os métodos baseados em contagem das células


Subject(s)
Cell Growth Processes , Fluorescence , Glioma/diagnosis , Actin Cytoskeleton/classification , Glioblastoma , Kelch-Like ECH-Associated Protein 1/adverse effects
11.
Article in English | WPRIM | ID: wpr-764233

ABSTRACT

The dynamics of the actin cytoskeleton plays a pivotal role in the process of cell division, the transportation of organelles, vesicle trafficking and cell movement. Human immunodeficiency virus type 1 (HIV-1) hijacks the actin dynamics network during the viral entry and migration of the pre-integration complex (PIC) into the nucleus. Actin dynamics linked to HIV-1 has emerged as a potent therapeutic target against HIV infection. Although some inhibitors have been intensely analyzed with regard to HIV-1 infection, their effects are sometimes disputed and the exact mechanisms for actin dynamics in HIV infection have not been well elucidated. In this study, the small molecules regulating HIV-1 infection from diverse inhibitors of the actin dynamic network were screened. Two compounds, including Chaetoglobosin A and CK-548, were observed to specifically bar the viral infection, while the cytochalasin family, 187-1, N-WASP inhibitor, Rho GTPase family inhibitors (EHop-016, CID44216842, and ML-141) and LIMK inhibitor (LIM domain kinase inhibitor) increased the viral infection without cytotoxicity within a range of ~ µM. However, previously known inhibitory compounds of HIV-1 infection, such as Latrunculin A, Jasplakinolide, Wiskostatin and Swinholide A, exhibited either an inhibitory effect on HIV-1 infection combined with severe cytotoxicity or showed no effects. Our data indicate that Chaetoglobosin A and CK-548 have considerable potential for development as new therapeutic drugs for the treatment of HIV infection. In addition, the newly identified roles of Cytochalasins and some inhibitors of Rho GTPase and LIMK may provide fundamental knowledge for understanding the complicated actin dynamic pathway when infected by HIV-1. Remarkably, the newly defined action modes of the inhibitors may be helpful in developing potent anti-HIV drugs that target the actin network, which are required for HIV infection.


Subject(s)
Actin Cytoskeleton , Actins , Anti-HIV Agents , Cell Division , Cell Movement , Cytochalasins , GTP Phosphohydrolases , HIV Infections , HIV-1 , Humans , Organelles , Phosphotransferases , Transportation
12.
Article in English | WPRIM | ID: wpr-742241

ABSTRACT

To survey the prevalence of Sarcocystis infections, 210 heart samples were collected from Korean native cattle (Bos taurus coreanae) at an abattoir in Daejeon Metropolitan City, Republic of Korea. Sarcocysts were detected form 31 specimens (14.8%) and identified as Sarcocystis cruzi via transmission electron microscopy. The wall of S. cruzi has flattened protrusions that did not contain fibrils or microfilaments. The protrusions arose irregularly from the base, contained a fine granular substance, lacked internal microfilaments, and measured approximately 0.21–1.25 μm in length and 0.05–0.07 μm in width. Sequence analysis revealed 99.5% homology to S. cruzi. This is the first report on the prevalence of S. cruzi in native cattle from the Republic of Korea.


Subject(s)
Abattoirs , Actin Cytoskeleton , Animals , Cattle , Heart , Korea , Microscopy, Electron, Transmission , Prevalence , Republic of Korea , Sarcocystis , Sequence Analysis
13.
Article in Korean | WPRIM | ID: wpr-718852

ABSTRACT

The cytoskeleton consists of 3 filamentous components: intermediate filaments, microtubules, and actin filaments. Actin filaments continuously assemble and disassemble far out of equilibrium to adapt cells in response to external stimuli. Actin filaments organization and dynamic are controlled by a multitude of actin-binding proteins including actin-bundling proteins. L-plastin, expressed abundantly in lymphocytes and monocytes, is an actin-bundling protein that roles in immune defense and in metastatic invasion of cancer cells. The actin-bundling activity of L-plastin is regulated not only by intracellular calcium concentration, but by phosphorylation of Ser5. The actin-bundling activity of L-pastin decreases by increased calcium concentration but is promoted by phosphorylation of Ser5. The morphology changes and motility of cells requires continuous remodeling of actin filaments which demands the sensitive nature of L-plastin to Ca2+-signal, phosphorylation of Ser5, and probably additional regulation. This review briefly describes the structure and regulation of L-plastin, and roles for L-plastin in cancer invasion and in macrophages.


Subject(s)
Actin Cytoskeleton , Calcium , Cytoskeleton , Intermediate Filaments , Lymphocytes , Macrophages , Microfilament Proteins , Microtubules , Monocytes , Phosphorylation
14.
Genomics & Informatics ; : 59-64, 2018.
Article in English | WPRIM | ID: wpr-716822

ABSTRACT

Although pork quality traits are important commercially, genome-wide association studies (GWASs) have not well considered Landrace and Yorkshire pigs worldwide. Landrace and Yorkshire pigs are important pork-providing breeds. Although quantitative trait loci of pigs are well-developed, significant genes in GWASs of pigs in Korea must be studied. Through a GWAS using the PLINK program, study of the significant genes in Korean pigs was performed. We conducted a GWAS and surveyed the gene ontology (GO) terms associated with the backfat thickness (BF) trait of these pigs. We included the breed information (Yorkshire and Landrace pigs) as a covariate. The significant genes after false discovery rate (<0.01) correction were AFG1L, SCAI, RIMS1, and SPDEF. The major GO terms for the top 5% of genes were related to neuronal genes, cell morphogenesis and actin cytoskeleton organization. The neuronal genes were previously reported as being associated with backfat thickness. However, the genes in our results were novel, and they included ZNF280D, BAIAP2, LRTM2, GABRA5, PCDH15, HERC1, DTNBP1, SLIT2, TRAPPC9, NGFR, APBB2, RBPJ, and ABL2. These novel genes might have roles in important cellular and physiological functions related to BF accumulation. The genes related to cell morphogenesis were NOX4, MKLN1, ZNF280D, BAIAP2, DNAAF1, LRTM2, PCDH15, NGFR, RBPJ, MYH9, APBB2, DTNBP1, TRIM62, and SLIT2. The genes that belonged to actin cytoskeleton organization were MKLN1, BAIAP2, PCDH15, BCAS3, MYH9, DTNBP1, ABL2, ADD2, and SLIT2.


Subject(s)
Actin Cytoskeleton , Gene Ontology , Genome-Wide Association Study , Korea , Morphogenesis , Neurons , Quantitative Trait Loci , Red Meat , Swine
15.
Article in Chinese | WPRIM | ID: wpr-775369

ABSTRACT

This paper aimed to observe the protective effect of catalpol on the high glucose induced destruction of tight junctions of rat primary brain microvascular endothelial cells (BMECs). Catalpol co-administrated with high glucose increased BMECs survival, decreased its ET-1 secretion, and improved transmembrane electrical resistance in a time-dependent manner. Furthermore, transmission electron microscopy was used to observe catalpol's protective effect on tight junction. Fluorescence staining displayed that catalpol reversed the rearrangement of the cytoskeleton protein F-actin and up-regulated the tight junction proteins claudin-5 and ZO-1, which were further demonstrated by the mRNA expression levels of claudin-5, occludin, ZO-1, ZO-2, ZO-3, -actintin, vinculin and cateinins. This study indicated that catalpol reverses the disaggregation of cytoskeleton actin in BMECs and up-regulates the expression of tight junction proteins, such as claudin-5, occludin, and ZO-1, and finally alleviates the increase in high glucose-induced BMECs injury.


Subject(s)
Actin Cytoskeleton , Actins , Metabolism , Animals , Brain , Cell Biology , Cells, Cultured , Claudin-5 , Metabolism , Endothelial Cells , Glucose , Iridoid Glucosides , Pharmacology , Phosphoproteins , Rats , Tight Junctions , Zonula Occludens-1 Protein , Metabolism
16.
Article in English | WPRIM | ID: wpr-758799

ABSTRACT

Pasteurella multocida serotype B:2 causes hemorrhagic septicemia in cattle and buffalo. The invasion mechanism of the bacterium when invading the bloodstream is unclear. This study aimed to characterize the effects of immunomodulatory molecules, namely dexamethasone and lipopolysaccharide, on the invasion efficiency of P. multocida serotype B:2 toward bovine aortic endothelial cells (BAECs) and the involvement of actin microfilaments in the invasion mechanism. The results imply that treatment of BAECs with lipopolysaccharide at 100 ng/mL for 24 h significantly increases the intracellular bacteria number per cell (p < 0.01) compared with those in untreated and dexamethasone-treated cells. The lipopolysaccharide-treated cells showed a significant decrease in F-actin expression and an increase in G-actin expression (p < 0.001), indicating actin depolymerization of BAECs. However, no significant differences were detected in the invasion efficiency and actin filament reorganization between the dexamethasone-treated and untreated cells. Transmission electron microscopy showed that P. multocida B:2 resided in a vacuolar compartment of dexamethasone-treated and untreated cells, whereas the bacteria resided in cellular membrane of lipopolysaccharide-treated cells. The results suggest that lipopolysaccharide destabilizes the actin filaments of BAECs, which could facilitate the invasion of P. multocida B:2 into BAECs.


Subject(s)
Actin Cytoskeleton , Actins , Animals , Bacteria , Buffaloes , Cattle , Dexamethasone , Endothelial Cells , Hemorrhagic Septicemia , In Vitro Techniques , Membranes , Microscopy, Electron, Transmission , Pasteurella multocida , Pasteurella , Serogroup
17.
Article in English | WPRIM | ID: wpr-644004

ABSTRACT

Recent investigations consider adipose-derived stemcells (ASCs) as a promising source of stemcells for clinical therapies. To obtain functional cells with enhanced cytoskeleton and aligned structure, mechanical stimuli are utilized during differentiation of stem cells to the target cells. Since function of muscle cells is associated with cytoskeleton, enhanced structure is especially essential for these cells when employed in tissue engineering. In this study by utilizing a custom-made device, effects of uniaxial tension (1Hz, 10% stretch) on cytoskeleton, cell alignment, cell elastic properties, and expression of smooth muscle cell (SMC) genes in ASCs are investigated.Due to proper availability ofASCs, results can be employed in cardiovascular engineeringwhen production of functional SMCs in arterial reconstruction is required. Results demonstrated that cells were oriented after 24 hours of cyclic stretch with aligned pseudo-podia. Staining of actin filaments confirmed enhanced polymerization and alignment of stress fibers. Such phenomenon resulted in stiffening of cell body which was quantified by atomic force microscopy (AFM). Expression of SM α-actin and SM22 α-actin as SMC associated genes were increased after cyclic stretch while GAPDH was considered as internal control gene. Finally, it was concluded that application of cyclic stretch on ASCs assists differentiation to SMC and enhances functionality of cells.


Subject(s)
Actin Cytoskeleton , Cell Body , Cytoskeleton , Microscopy, Atomic Force , Muscle Cells , Muscle, Smooth , Myocytes, Smooth Muscle , Polymerization , Polymers , Stem Cells , Stress Fibers , Tissue Engineering
18.
Article in English | WPRIM | ID: wpr-728679

ABSTRACT

Adhesion events of monocytes represent an important step in inflammatory responses induced by chemokines. The β1-integrin CD29 is a major adhesion molecule regulating leukocyte migration and extravasation. Although several adhesion molecules have been known as regulators of CD29, the molecular interactions between CD29 and its regulatory adhesion molecules (such as CD98 and CD147) have not been fully elucidated. Therefore, in this study, we examined whether these molecules are functionally, biochemically, and cell-biologically associated using monocytic U937 cells treated with aggregation-stimulating and blocking antibodies, as well as enzyme inhibitors. The surface levels of CD29, CD98, and CD147 (but not CD43, CD44, and CD82) were increased. The activation of CD29, CD98, and CD147 by ligation of them with aggregation-activating antibodies triggered the induction of cell-cell adhesion, and sensitivity to various enzyme inhibitors and aggregation-blocking antibodies was similar for CD29-, CD98-, and CD147-induced U937 cell aggregation. Molecular association between these molecules and the actin cytoskeleton was confirmed by confocal microscopy and immunoprecipitation. These results strongly suggest that CD29 might be modulated by its biochemical and cellular regulators, including CD98 and CD147, via the actin cytoskeleton.


Subject(s)
Actin Cytoskeleton , Antibodies , Antibodies, Blocking , Chemokines , Enzyme Inhibitors , Immunoprecipitation , Leukocytes , Ligation , Microscopy, Confocal , Monocytes , U937 Cells
19.
Article in English | WPRIM | ID: wpr-84979

ABSTRACT

Serum response factor (SRF) is a master transcription factor of the actin cytoskeleton that binds to highly conserved CArG boxes located within the majority of smooth muscle cell (SMC)-restricted promoters/enhancers. Although most studies of SRF focus on skeletal muscle, cardiac muscle, and vascular SMCs, SRF research has recently expanded into the gastrointestinal (GI) system. Genome scale analyses of GI SMC transcriptome and CArG boxes (CArGome) have identified new SRF target genes. In addition to circular and longitudinal smooth muscle layers, SRF is also expressed in GI mucosa and cancers. In the GI tract, SRF is the central regulator of genes involved in apoptosis, dedifferentiation, proliferation, and migration of cells. Since SRF is the cell phenotypic modulator, it may play an essential role in the development of myopathy, hypertrophy, ulcers, gastric and colon cancers within the GI tract. Given the multi-functional role displayed by SRF in the digestive system, SRF has received more attention emerging as a potential therapeutic target. This review summarizes the findings in SRF research pertaining to the GI tract and provides valuable insight into future directions.


Subject(s)
Actin Cytoskeleton , Apoptosis , Colonic Neoplasms , Digestive System , Gastrointestinal Diseases , Gastrointestinal Tract , Genome , Hypertrophy , MicroRNAs , Mucous Membrane , Muscle Cells , Muscle, Skeletal , Muscle, Smooth , Muscular Diseases , Myocardium , Myocytes, Smooth Muscle , Serum Response Factor , Stomach Ulcer , Transcription Factors , Transcriptome
20.
Article in English | WPRIM | ID: wpr-84977

ABSTRACT

An increase in intracellular Ca2+ is the primary trigger of contraction of gastrointestinal (GI) smooth muscles. However, increasing the Ca2+ sensitivity of the myofilaments by elevating myosin light chain phosphorylation also plays an essential role. Inhibiting myosin light chain phosphatase activity with protein kinase C-potentiated phosphatase inhibitor protein-17 kDa (CPI-17) and myosin phosphatase targeting subunit 1 (MYPT1) phosphorylation is considered to be the primary mechanism underlying myofilament Ca2+ sensitization. The relative importance of Ca2+ sensitization mechanisms to the diverse patterns of GI motility is likely related to the varied functional roles of GI smooth muscles. Increases in CPI-17 and MYPT1 phosphorylation in response to agonist stimulation regulate myosin light chain phosphatase activity in phasic, tonic, and sphincteric GI smooth muscles. Recent evidence suggests that MYPT1 phosphorylation may also contribute to force generation by reorganization of the actin cytoskeleton. The mechanisms responsible for maintaining constitutive CPI-17 and MYPT1 phosphorylation in GI smooth muscles are still largely unknown. The characteristics of the cell-types comprising the neuroeffector junction lead to fundamental differences between the effects of exogenous agonists and endogenous neurotransmitters on Ca2+ sensitization mechanisms. The contribution of various cell-types within the tunica muscularis to the motor responses of GI organs to neurotransmission must be considered when determining the mechanisms by which Ca2+ sensitization pathways are activated. The signaling pathways regulating Ca2+ sensitization may provide novel therapeutic strategies for controlling GI motility. This article will provide an overview of the current understanding of the biochemical basis for the regulation of Ca2+ sensitization, while also discussing the functional importance to different smooth muscles of the GI tract.


Subject(s)
Actin Cytoskeleton , Calcium , Gastrointestinal Motility , Gastrointestinal Tract , Muscle, Smooth , Myofibrils , Myosin Light Chains , Myosin-Light-Chain Phosphatase , Neuroeffector Junction , Neurotransmitter Agents , Phosphorylation , Protein Kinases , Signal Transduction , Synaptic Transmission
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