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201.
Cell migration and invasion requires the precise temporal and spatial orchestration of a variety of biological processes. Filaments of polymerized actin are critical players in these diverse processes, including the regulation of cell anchorage points (both cell-cell and cell-extracellular matrix), the uptake and delivery of molecules via endocytic pathways and the generation of force for both membrane protrusion and retraction. How the actin filaments are specialized for each of these discrete functions is yet to be comprehensively elucidated. The cytoskeletal tropomyosins are a family of actin associating proteins that form head-to-tail polymers which lay in the major groove of polymerized actin filaments. In the present review we summarize the emerging isoform-specific functions of tropomyosins in cell migration and invasion and discuss their potential roles in the specialization of actin filaments for the diverse cellular processes that together regulate cell migration and invasion.Key words: tropomyosin, actin, migration, invasion, cytoskeleton, actin dynamics, adhesionActin is the most abundant protein in eukaryotic cells and is critical for maintaining structural integrity. The polymerization of globular (G)-actin monomers forms actin filaments (F-actin),1 which play a role in diverse and complex cellular functions including intercellular transport of organelles and vesicles,2,3 cytokinesis,4 apoptosis5 and cell motility.6 Intricate details describing the molecular scale interactions between regulatory proteins and actin have been extensively investigated but the mechanistic control of diverse actin filament functions remain largely unclear. Recent improvements in analysis techniques7 and the use of physiologically relevant models of 3D cell culturing8 have now begun to reveal mechanisms of actin cytoskeleton regulation. Accruing evidence suggests that the actin decorating protein tropomyosin is a key regulator of actin filament specialization. Of particular interest is the impact that tropomyosin regulation has on actin filament activity during cell migration and invasion that underpins immunological cell homing, development, wound healing and metastasis. 相似文献
202.
Sheng-Chieh Lien Shun-Fu Chang Pei-Ling Lee Shu-Yi Wei Margaret Dah-Tsyr Chang Jang-Yang Chang Jeng-Jiann Chiu 《Biochimica et Biophysica Acta (BBA)/Molecular Cell Research》2013,1833(12):3124-3133
Mechanical forces induced by interstitial fluid flow in and surrounding tissues and by blood/lymphatic flow in vessels may modulate cancer cell invasion and metastasis and anticancer drug delivery. Our previous study demonstrated that laminar flow-induced shear stress induces G2/M arrest in tumor cells. However, whether shear stress modulates final cell fate remains unclear. In this study, we investigated the role of flow-induced shear stress in modulating the survival of four human tumor cell lines, i.e., Hep3B hepatocarcinoma cells, MG63 osteosarcoma cells, SCC25 oral squamous carcinoma cells, and A549 carcinomic alveolar basal epithelial cells. Laminar shear stress (LSS) ranging from 0.5 to 12 dyn/cm2 induced death of these four tumor cell lines. In contrast to LSS at 0.5 dyn/cm2, oscillatory shear stress (OSS) at 0.5 ± 4 dyn/cm2 cannot induce cancer cell death. Both LSS and OSS had no effect on human normal hepatocyte, lung epithelial, and endothelial cells. Application of LSS to these four cell lines increased the percentage of cells stained positively for annexin V–FITC, with up-regulations of cleaved caspase-8, -9, and -3, and PARP. In addition, LSS also induced Hep3B cell autophagy, as detected by acidic vesicular organelle formation, LC3B transformation, and p62/SQSTM1 degradation. By transfecting with small interfering RNA, we found that the shear-induced apoptosis and autophagy are mediated by bone morphogenetic protein receptor type (BMPR)-IB, BMPR-specific Smad1 and Smad5, and p38 mitogen-activated protein kinase in Hep3B cells. Our findings provide insights into the molecular mechanisms by which shear stress induces apoptosis and autophagy in tumor cells. 相似文献
203.
Dae‐Won Ki Takeshi Kodama Ahmed H. El‐Desoky Chin Piow Wong Hien Minh Nguyen Kiep Minh Do Quang Minh Thai Lien Huong Ton Nu Hiroyuki Morita 《化学与生物多样性》2020,17(9)
A new decenoic acid derivative, gelliodesinic acid, and a naturally new alkaloid, together with three known furanoterpenoids and two known indole alkaloids, were isolated from the MeOH extract of the marine sponge Gelliodes sp. collected in Vietnam. The chemical structures of the isolated compounds were determined by analyses of 1D‐ and 2D‐NMR and MS data and by comparisons of the data with those reported in the literature. The cytotoxicity assay against HeLa, MCF‐7, and A549 cancer cell lines revealed that the three known furanoterpenes exhibited cytotoxic activities with IC50 values ranging from 23.6 to 75.5 μM against the three cell lines, and that 1H‐indole‐3‐carboxylic acid showed cytotoxicity with an IC50 value of 89.2 μM against A549 cancer cell lines. 相似文献
204.
Ninh Khac Ban Vu Huong Giang Tran My Linh Le Quynh Lien Ninh Thi Ngoc Do Thi Thao Nguyen Hoai Nam Nguyen Xuan Cuong Phan Van Kiem Chau Van Minh 《Phytochemistry letters》2013,6(2):267-269
This work was done as a part of our ongoing projects to catalog the chemical constituents and biological activities of the Morinda species growing in Vietnam. Phytochemical investigations of the methanol extract of Morinda umbellata aerial parts resulted in the isolation of two new 11-noriridoids, umbellatolides A (1) and B (2). Their structures were elucidated by NMR (1H NMR, 13C NMR, HSQC, HMBC, 1H–1H COSY, and NOESY) and FTICRMS data. This is the first report of 11-noriridoids from M. umbellata. The cytotoxic activity and protective effect on oxidative stress injury stimulated by H2O2 in murine hepatocyte of 1 and 2 were also evaluated. 相似文献
205.
Rachel M. Smith Tuan Anh Nguyen Hoang Thi Thanh Ha Pham Hong Thang Cao Thuy Truong Xuan Lien Hien T. Bui Thai Hung Le Bruce Struminger Michelle S. McConnell Robyn Neblett Fanfair Benjamin J. Park Julie R. Harris 《PloS one》2013,8(4)
Background
An estimated 120,000 HIV-associated cryptococcal meningitis (CM) cases occur each year in South and Southeast Asia; early treatment may improve outcomes. The World Health Organization (WHO) recently recommended screening HIV-infected adults with CD4<100 cells/mm3 for serum cryptococcal antigen (CrAg), a marker of early cryptococcal infection, in areas of high CrAg prevalence. We evaluated CrAg prevalence and cost-effectiveness of this screening strategy in HIV-infected adults in northern and southern Vietnam.Methods
Serum samples were collected and stored during 2009–2012 in Hanoi and Ho Chi Minh City, Vietnam, from HIV-infected, ART-naïve patients presenting to care in 12 clinics. All specimens from patients with CD4<100 cells/mm3 were tested using the CrAg lateral flow assay. We obtained cost estimates from laboratory staff, clinicians and hospital administrators in Vietnam, and evaluated cost-effectiveness using WHO guidelines.Results
Sera from 226 patients [104 (46%) from North Vietnam and 122 (54%) from the South] with CD4<100 cells/mm3 were available for CrAg testing. Median CD4 count was 40 (range 0–99) cells/mm3. Nine (4%; 95% CI 2–7%) specimens were CrAg-positive. CrAg prevalence was higher in South Vietnam (6%; 95% CI 3–11%) than in North Vietnam (2%; 95% CI 0–6%) (p = 0.18). Cost per life-year gained under a screening scenario was $190, $137, and $119 at CrAg prevalences of 2%, 4% and 6%, respectively.Conclusion
CrAg prevalence was higher in southern compared with northern Vietnam; however, CrAg screening would be considered cost-effective by WHO criteria in both regions. Public health officials in Vietnam should consider adding cryptococcal screening to existing national guidelines for HIV/AIDS care. 相似文献206.
R.A. Gibson M.A. Neumann E.L. Lien K.A. Boyd W.C. Tu 《Prostaglandins, leukotrienes, and essential fatty acids》2013,88(1):139-146
The conversion of the plant-derived omega-3 (n-3) α-linolenic acid (ALA, 18:3n-3) to the long-chain eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3) can be increased by ALA sufficient diets compared to ALA deficient diets. Diets containing ALA above an optimal level result in no further increase in DHA levels in animals and humans. The present study evaluates means of maximizing plasma DHA accumulation by systematically varying both linoleic acid (LA, 18:2n-6) and ALA dietary level. Weanling rats were fed one of 54 diets for three weeks. The diets varied in the percentage of energy (en%) of LA (0.07–17.1 en%) and ALA (0.02–12.1 en%) by manipulating both the fat content and the balance of vegetable oils. The peak of plasma phospholipid DHA (>8% total fatty acids) was attained as a result of feeding a narrow dietary range of 1–3 en% ALA and 1–2 en% LA but was suppressed to basal levels (~2% total fatty acids) at dietary intakes of total polyunsaturated fatty acids (PUFA) above 3 en%. We conclude it is possible to enhance the DHA status of rats fed diets containing ALA as the only source of n-3 fatty acids but only when the level of dietary PUFA is low (<3 en%). 相似文献
207.
Rob Moerkens Apostolos Pekas Stijn Bellinkx Inge Hanssen Marlies Huysmans Lien Bosmans Felix Wäckers 《Journal of Applied Entomology》2020,144(7):566-577
The use of Nesidiocoris tenuis (Hemiptera: Miridae) as a biocontrol agent is controversial as it is considered a pest in Northwest European tomato greenhouses, due to its tendency to damage the plant and fruit. Necessary chemical plant protection products to control N. tenuis have toxic side effects on important beneficials like Macrolophus pygmaeus (Hemiptera: Miridae), which jeopardizes the whole IPM programme. In this study, several commercial tomato greenhouses were monitored for mirid populations. The relationship between the number of N. tenuis individuals and plant damage was assessed in function of availability of prey and interaction with M. pygmaeus. These greenhouse data were used to determine a practical density intervention threshold. Next, the hypothesis that a Pepino mosaic virus (PepMV) infection increases plant and fruit damage by N. tenuis (as has been shown for M. pygmaeus) was tested. Plant damage occurred when the average number of predatory bugs in the head of the plant exceeded 16 per ten plants. Plant damage increased in severity at increasing predatory bug densities, independent of the availability of prey and M. pygmaeus presence. Plant and fruit damage were not affected by the presence of PepMV, as was shown for fruit damage in previous studies for M. pygmaeus. Our study provides a practical density intervention threshold for growers in greenhouse crops. Simple monitoring of the number of predatory bugs in the head of the plant can be used to take specific biocontrol actions. It was also shown that only the predatory bug N. tenuis itself causes damage, and there is no interaction with PepMV. 相似文献
208.
Quantitative trait loci for clinical mastitis on chromosomes 2, 6, 14 and 20 in Norwegian Red cattle 总被引:3,自引:0,他引:3
Sodeland M Kent MP Olsen HG Opsal MA Svendsen M Sehested E Hayes BJ Lien S 《Animal genetics》2011,42(5):457-465
Mastitis is the most frequent and costly disease in dairy production and solutions leading to a reduction in the incidence of mastitis are highly demanded. Here a genome-wide association study was performed to identify polymorphisms affecting susceptibility to mastitis. Genotypes for 17 349 SNPs distributed across the 29 bovine autosomal chromosomes from a total of 2589 sires with 1 389 776 daughters with records on clinical mastitis were included in the analysis. Records of occurrence of clinical mastitis were divided into seven time periods in the first three lactations in order to identify quantitative trait loci affecting mastitis susceptibility in particular phases of lactation. The most convincing results from the association mapping were followed up and validated by a combined linkage disequilibrium and linkage analysis. The study revealed quantitative trait loci affecting occurrence of clinical mastitis in the periparturient period on chromosomes 2, 6 and 20 and a quantitative trait locus affecting occurrence of clinical mastitis in late lactation on chromosome 14. None of the quantitative trait loci for clinical mastitis detected in the study seemed to affect lactation average of somatic cell score. The SNPs highly associated with clinical mastitis lie near both the gene encoding interleukin 8 on chromosome 6 and the genes encoding the two interleukin 8 receptors on chromosome 2. 相似文献
209.
Prosen KR Carroll RK Burda WN Krute CN Bhattacharya B Dao ML Turos E Shaw LN 《Bioorganic & medicinal chemistry letters》2011,21(18):5293-5295
Bacterial fatty acid synthesis (FAS) is a potentially important, albeit controversial, target for antimicrobial therapy. Recent studies have suggested that the addition of exogenous fatty acids (FAs) to growth media can circumvent the effects of FAS-targeting compounds on bacterial growth. Consequently, such agents may have limited in vivo applicability for the treatment of human disease, as free FAs are abundant within the body. Our group has previously developed N-thiolated β-lactams and found they function by interfering with FAS in select pathogenic bacteria, including MRSA. To determine if the FAS targeting activity of N-thiolated β-lactams can be abrogated by exogenous fatty acids, we performed MIC determinations for MRSA strains cultured with the fatty acids oleic acid and Tween 80. We find that, whilst the activity of the known FAS inhibitor triclosan is severely compromised by the addition of both oleic acid and Tween 80, exogenous FAs do not mitigate the antibacterial activity of N-thiolated β-lactams towards MRSA. Consequently, we propose that N-thiolated β-lactams are unique amongst FAS-inhibiting antimicrobials, as their effects are unimpeded by exogenous FAs. 相似文献
210.
Illustrated identification keys are provided for higher taxa and all genera of social wasps found in South‐East Asia. 相似文献