scholarly journals Talin requires beta-integrin, but not vinculin, for its assembly into focal adhesion-like structures in the nematode Caenorhabditis elegans.

1996 ◽  
Vol 7 (8) ◽  
pp. 1181-1193 ◽  
Author(s):  
G L Moulder ◽  
M M Huang ◽  
R H Waterston ◽  
R J Barstead

In cultured cells, the 230-kDa protein talin is found at discrete plasma membrane foci known as focal adhesions, sites that anchor the intracellular actin cytoskeleton to the extracellular matrix. The regulated assembly of focal adhesions influences the direction of cell migrations or the reorientation of cell shapes. Biochemical studies of talin have shown that it binds to the proteins integrin, vinculin, and actin in vitro. To understand the function of talin in vivo and to correlate its in vitro and in vivo biochemical properties, various genetic approaches have been adopted. With the intention of using genetics in the study of talin, we identified a homologue to mouse talin in a genetic model system, the nematode Caenorhabditis elegans. C. elegans talin is 39% identical and 59% similar to mouse talin. In wild-type adult C. elegans, talin colocalizes with integrin, vinculin, and alpha-actinin in the focal adhesion-like structures found in the body-wall muscle. By examining the organization of talin in two different C. elegans mutant strains that do not make either beta-integrin or vinculin, we were able to determine that talin does not require vinculin for its initial organization at the membrane, but that it depends critically on the presence of integrin for its initial assembly at membrane foci.

2021 ◽  
pp. 1-9
Author(s):  
Dayana Torres Valladares ◽  
Sirisha Kudumala ◽  
Murad Hossain ◽  
Lucia Carvelli

Amphetamine is a potent psychostimulant also used to treat attention deficit/hyperactivity disorder and narcolepsy. In vivo and in vitro data have demonstrated that amphetamine increases the amount of extra synaptic dopamine by both inhibiting reuptake and promoting efflux of dopamine through the dopamine transporter. Previous studies have shown that chronic use of amphetamine causes tolerance to the drug. Thus, since the molecular mechanisms underlying tolerance to amphetamine are still unknown, an animal model to identify the neurochemical mechanisms associated with drug tolerance is greatly needed. Here we took advantage of a unique behavior caused by amphetamine in <i>Caenorhabditis elegans</i> to investigate whether this simple, but powerful, genetic model develops tolerance following repeated exposure to amphetamine. We found that at least 3 treatments with 0.5 mM amphetamine were necessary to see a reduction in the amphetamine-induced behavior and, thus, to promote tolerance. Moreover, we found that, after intervals of 60/90 minutes between treatments, animals were more likely to exhibit tolerance than animals that underwent 10-minute intervals between treatments. Taken together, our results show that <i>C. elegans</i> is a suitable system to study tolerance to drugs of abuse such as amphetamines.


1986 ◽  
Vol 103 (1) ◽  
pp. 23-31 ◽  
Author(s):  
E J Aamodt ◽  
J G Culotti

The nematode Caenorhabditis elegans should be an excellent model system in which to study the role of microtubules in mitosis, embryogenesis, morphogenesis, and nerve function. It may be studied by the use of biochemical, genetic, molecular biological, and cell biological approaches. We have purified microtubules and microtubule-associated proteins (MAPs) from C. elegans by the use of the anti-tumor drug taxol (Vallee, R. B., 1982, J. Cell Biol., 92:435-44). Approximately 0.2 mg of microtubules and 0.03 mg of MAPs were isolated from each gram of C. elegans. The C. elegans microtubules were smaller in diameter than bovine microtubules assembled in vitro in the same buffer. They contained primarily 9-11 protofilaments, while the bovine microtubules contained 13 protofilaments. The principal MAP had an apparent molecular weight of 32,000 and the minor MAPs were 30,000, 45,000, 47,000, 50,000, 57,000, and 100,000-110,000 mol wt as determined by SDS-gel electrophoresis. The microtubules were observed, by electron microscopy of negatively stained preparations, to be connected by stretches of highly periodic cross-links. The cross-links connected the adjacent protofilaments of aligned microtubules, and occurred at a frequency of one cross-link every 7.7 +/- 0.9 nm, or one cross-link per tubulin dimer along the protofilament. The cross-links were removed when the MAPs were extracted from the microtubules with 0.4 M NaCl. The cross-links then re-formed when the microtubules and the MAPs were recombined in a low salt buffer. These results strongly suggest that the cross-links are composed of MAPs.


2005 ◽  
Vol 73 (11) ◽  
pp. 7236-7242 ◽  
Author(s):  
Creg Darby ◽  
Sandya L. Ananth ◽  
Li Tan ◽  
B. Joseph Hinnebusch

ABSTRACT Yersinia pestis, the cause of bubonic plague, blocks feeding by its vector, the flea. Recent evidence indicates that blockage is mediated by an in vivo biofilm. Y. pestis and the closely related Yersinia pseudotuberculosis also make biofilms on the cuticle of the nematode Caenorhabditis elegans, which block this laboratory animal's feeding. Random screening of Y. pseudotuberculosis transposon insertion mutants with a C. elegans biofilm assay identified gmhA as a gene required for normal biofilms. gmhA encodes phosphoheptose isomerase, an enzyme required for synthesis of heptose, a conserved component of lipopolysaccharide and lipooligosaccharide. A Y. pestis gmhA mutant was constructed and was severely defective for C. elegans biofilm formation and for flea blockage but only moderately defective in an in vitro biofilm assay. These results validate use of the C. elegans biofilm system to identify genes and pathways involved in Y. pestis flea blockage.


1999 ◽  
Vol 112 (24) ◽  
pp. 4589-4599 ◽  
Author(s):  
F. Li ◽  
Y. Zhang ◽  
C. Wu

Integrin-linked kinase (ILK) is a ubiquitously expressed protein serine/threonine kinase that has been implicated in integrin-, growth factor- and Wnt-signaling pathways. In this study, we show that ILK is a constituent of cell-matrix focal adhesions. ILK was recruited to focal adhesions in all types of cells examined upon adhesion to a variety of extracellular matrix proteins. By contrast, ILK was absent in E-cadherin-mediated cell-cell adherens junctions. In previous studies, we have identified PINCH, a protein consisting of five LIM domains, as an ILK binding protein. We demonstrate in this study that the ILK-PINCH interaction requires the N-terminal-most ANK repeat (ANK1) of ILK and one (the C-terminal) of the two zinc-binding modules within the LIM1 domain of PINCH. The ILK ANK repeats domain, which is capable of interacting with PINCH in vitro, could also form a complex with PINCH in vivo. However, the efficiency of the complex formation or the stability of the complex was markedly reduced in the absence of the C-terminal domain of ILK. The PINCH binding defective ANK1 deletion ILK mutant, unlike the wild-type ILK, was unable to localize and cluster in focal adhesions, suggesting that the interaction with PINCH is necessary for focal adhesion localization and clustering of ILK. The N-terminal ANK repeats domain, however, is not sufficient for mediating focal adhesion localization of ILK, as an ILK mutant containing the ANK repeats domain but lacking the C-terminal integrin binding site failed to localize in focal adhesions. These results suggest that focal adhesions are a major subcellular compartment where ILK functions in intracellular signal transduction, and provide important evidence for a critical role of PINCH and integrins in regulating ILK cellular function.


Antioxidants ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 811
Author(s):  
Cristina Moliner ◽  
Víctor López ◽  
Lillian Barros ◽  
Maria Inês Dias ◽  
Isabel C. F. R. Ferreira ◽  
...  

Rosmarinus officinalis L., commonly known as rosemary, has been largely studied for its wide use as food ingredient and medicinal plant; less attention has been given to its edible flowers, being necessary to evaluate their potential as functional foods or nutraceuticals. To achieve that, the phenolic profile of the ethanolic extract of R. officinalis flowers was determined using LC-DAD-ESI/MSn and then its antioxidant and anti-ageing potential was studied through in vitro and in vivo assays using Caenorhabditis elegans. The phenolic content was 14.3 ± 0.1 mg/g extract, trans rosmarinic acid being the predominant compound in the extract, which also exhibited a strong antioxidant capacity in vitro and increased the survival rate of C. elegans exposed to lethal oxidative stress. Moreover, R. officinalis flowers extended C. elegans lifespan up to 18%. Therefore, these findings support the potential use of R. officinalis flowers as ingredients to develop products with pharmaceutical and/or nutraceutical potential.


2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Fujie Yan ◽  
Yushu Chen ◽  
Ramila Azat ◽  
Xiaodong Zheng

Mulberry anthocyanins possess many pharmacological effects including liver protection, anti-inflammation, and anticancer. The aim of this study was to evaluate whether mulberry anthocyanin extract (MAE) exerts beneficial effects against oxidative stress damage in HepG2 cells and Caenorhabditis elegans. In vitro, MAE prevented cytotoxicity, increased glucose consumption and uptake, and eliminated excessive intracellular free radicals in H2O2-induced cells. Moreover, MAE pretreatment maintained Nrf2, HO-1, and p38 MAPK stimulation and abolished upregulation of p-JNK, FOXO1, and PGC-1α that were involved in oxidative stress and insulin signalling modulation. In vivo, extended lifespan was observed in C. elegans damaged by paraquat in the presence of MAE, while these beneficial effects were disappeared in pmk-1 and daf-16 mutants. PMK-1 and SKN-1 were activated after exposure to paraquat and MAE suppressed PMK-1 activation but enhanced SKN-1 stimulation. Our findings suggested that MAE recovered redox status in HepG2 cells and C. elegans that suffered from oxidative stress, which might be by targeting MAPKs and Nrf2.


2016 ◽  
Author(s):  
Mansour Sobeh ◽  
Esraa A ElHawary ◽  
Herbenya Peixoto ◽  
Rola M Labib ◽  
Heba Handoussa ◽  
...  

Background: Schotia brachypetala Sond. (Fabaceae) is an endemic tree of Southern Africa whose phytochemistry and pharmacology were slightly studied.The present work aimed at profiling the major phenolics compounds present in the hydro-alcoholic extract from S. brachypetala leaves (SBE) using LC/HRESI/MS/MS and NMR and prove their antioxidant capabilities using novel methods. Methods: In vitro assays; DPPH, TEAC persulfate decolorizing kinetic and FRAP assays, and in vivo assays: Caenorhabditis elegans strains maintenance, Intracellular ROS in C. elegans, Survival assay, GFP expression and Subcellular DAF-16 localization were employed to evaluate the antioxidant activity. Results: More than forty polyphenols ,including flavonoid glycosides, galloylated flavonoid glycosides, isoflavones, dihydrochalcones, procyanidins, anthocyanins, hydroxybenzoic acid derivatives, hydrolysable tannins, and traces of methylated and acetylated flavonoid derivatives were identified. Three compounds were isolated and identified from the genus Schotia for the first time, namely gallic acid, myricetin-3-O-α-L-1C4-rhamnoside and quercetin-3-O-L-1C4-rhamnoside.The tested extract was able to protect the worms against juglone induced oxidative stress and attenuate the reactive oxygen species (ROS) accumulation. SBE was also able to attenuate the levels of heat shock protein (HSP) expression. Discussion: A pronounced antioxidant activity in vivo, which can be attributed to its ability to promote the nuclear translocation of DAF-16/FOXO, the main transcription factor regulating the expression of stress response genes. The remarkable antioxidant activity in vitro and in vivo correlates to SBE rich phenolic profile.


PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e1879 ◽  
Author(s):  
Erjia Wang ◽  
Michael Wink

Green vegetables are thought to be responsible for several beneficial properties such as antioxidant, anti-mutagenic, and detoxification activities. It is not known whether these effects are due to chlorophyll which exists in large amounts in many foods or result from other secondary metabolites. In this study, we used the model systemCaenorhabditis elegansto investigate the anti-oxidative and anti-aging effects of chlorophyllin vivo. We found that chlorophyll significantly improves resistance to oxidative stress. It also enhances the lifespan ofC. elegansby up to 25% via activation of the DAF-16/FOXO-dependent pathway. The results indicate that chlorophyll is absorbed by the worms and is thus bioavailable, constituting an important prerequisite for antioxidant and longevity-promoting activities inside the body. Our study thereby supports the view that green vegetables may also be beneficial for humans.


Antioxidants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1744
Author(s):  
Tao Chen ◽  
Siyuan Luo ◽  
Xiaoju Wang ◽  
Yiling Zhou ◽  
Yali Dai ◽  
...  

Blumea laciniata is widely used as a folk medicine in Asia, but relevant literature on it is rarely reported. We confirmed that polyphenol extract (containing chlorogenic acid, rutin, and luteolin-4-O-glucoside) from B. laciniata (EBL) showed strong antioxidant ability in vitro. Hence, in this work, we applied Caenorhabditis elegans to further investigate the antioxidant and anti-ageing abilities of EBL in vivo. The results showed that EBL enhanced the survival of C. elegans under thermal stress by 12.62% and sharply reduced the reactive oxygen species level as well as the content of malonaldehyde. Moreover, EBL increased the activities of antioxidant enzymes such as catalase and superoxide dismutase. Additionally, EBL promoted DAF-16, a transcription factor, into the nucleus. Besides, EBL extended the lifespan of C. elegans by 17.39%, showing an anti-ageing effect. Different mutants indicated that the insulin/IGF-1 signaling pathway participated in the antioxidant and anti-ageing effect of EBL on C. elegans.


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