Cellular Effects of Cytochalasins

1990 ◽  
pp. 395-402 ◽  
Author(s):  
Shinsaku Natori ◽  
Ichiro Yahara
Keyword(s):  
Cellular Effects

The Role of Purinergic Signaling in Trichomonas vaginalis Infection

2020 ◽  
Vol 20 ◽  
Author(s):  
Micheli Ferla ◽  
Tiana Tasca
Keyword(s):  
Drug Targets ◽  
Trichomonas Vaginalis ◽  
Hiv Transmission ◽  
Cell Damage ◽  
Purinergic Signaling ◽  
Host Cells ◽  
Purine Nucleotides ◽  
Cellular Effects ◽  
Adverse Pregnancy ◽  
Purine Salvage Pathways

: Trichomoniasis, one of the most common non-viral sexually transmitted infections worldwide, is caused by the parasite Trichomonas vaginalis. The pathogen colonizes the human urogenital tract and the infection is associated with complications such as adverse pregnancy outcomes, cervical cancer, and an increase in HIV transmission. The mecha-nisms of pathogenicity are multifactorial, and controlling immune responses is essential for infection maintenance. Extra-cellular purine nucleotides are released by cells in physiological and pathological conditions, and they are hydrolyzed by enzymes called ecto-nucleotidases. The cellular effects of nucleotides and nucleosides occur via binding to purinoceptors, or throughthe uptake by nucleoside transporters. Altogether, enzymes, receptors and transporters constitute the purinergic signaling, a cellular network that regulates several effects in practically all systems including mammals, helminths, proto-zoa, bacteria, and fungi. In this context, this review updates the data on purinergic signaling involved in T. vaginalis biol-ogy and interaction with host cells, focusing on the characterization of ecto-nucleotidases and on purine salvage pathways. The implications of the final products, the nucleosides adenosine and guanosine, for human neutrophil response and vagi-nal epithelial cell damage reveal the purinergic signaling as a potential new mechanism for alternative drug targets.

scholarly journals Synthetic lipopeptide Pam3CysSer(Lys)4 is an effective activator of human platelets

1994 ◽  
Vol 266 (6) ◽  
pp. C1684-C1691 ◽  
Author(s):  
M. Berg ◽  
S. Offermanns ◽  
R. Seifert ◽  
G. Schultz
Keyword(s):  
Calcium Concentration ◽  
Cytosolic Calcium ◽  
Human Platelets ◽  
Cellular Effects ◽  
Prostacyclin Receptor ◽  
Serotonin Secretion ◽  
Peptide Moiety ◽  
Lipid Moiety ◽  
Molecular Masses ◽  
Aggregation Of Platelets

Lipopeptide analogues of the NH2-terminus of bacterial lipoprotein are known to induce activation of macrophages, neutrophils, and lymphocytes. We studied the effect of the lipopeptide N-palmitoyl-S-[2,3-bis(palmitoyloxy)-(2RS)-propyl]-(R)-cysteinyl-( S)-seryl-(S)-lysyl-(S)-lysyl-(S)-lysyl-(S)-lysine [Pam3CysSer(Lys)4] on several functions of human platelets. Pam3CysSer(Lys)4 led to the aggregation of platelets and induced the secretion of serotonin with an effectiveness similar to thrombin. These cellular effects of Pam3CysSer(Lys)4 were concentration dependent, being half maximal at 2-3 microM and maximal at 10-30 microM. Another lipopeptide also induced platelet aggregation and serotonin secretion but was less potent and less effective than Pam3CysSer(Lys)4. The lipid moiety and the peptide moiety of Pam3CysSer(Lys)4 alone were without any effect. Lipopeptides also stimulated tyrosine phosphorylation of several proteins with molecular masses similar to those found to be tyrosine phosphorylated in response to thrombin, and Pam3CysSer(Lys)4 led to an increase in the cytosolic calcium concentration. All studied responses of platelets to lipopeptides were inhibited by the prostacyclin receptor agonist cicaprost. Taken together, our data show that lipopeptides are effective activators of human platelets and that this activation is susceptible to the action of physiological platelet inhibitors.

Clinical and cellular effects of hypothermia, acidosis and coagulopathy in major injury

2011 ◽  
Vol 98 (7) ◽  
pp. 894-907 ◽  
Author(s):  
K. Thorsen ◽  
K. G. Ringdal ◽  
K. Strand ◽  
E. Søreide ◽  
J. Hagemo ◽  
...  
Keyword(s):  
Cellular Effects ◽  
Major Injury

scholarly journals On the Need to Tell Apart Fraternal Twins eEF1A1 and eEF1A2, and Their Respective Outfits

2021 ◽  
Vol 22 (13) ◽  
pp. 6973
Author(s):  
Alberto Mills ◽  
Federico Gago
Keyword(s):  
De Novo ◽  
Elongation Factor ◽  
Missense Mutations ◽  
Developmentally Regulated ◽  
High Sequence Identity ◽  
80S Ribosome ◽  
Cellular Effects ◽  
Cellular Processes ◽  
Eukaryotic Elongation Factor ◽  
A Site

eEF1A1 and eEF1A2 are paralogous proteins whose presence in most normal eukaryotic cells is mutually exclusive and developmentally regulated. Often described in the scientific literature under the collective name eEF1A, which stands for eukaryotic elongation factor 1A, their best known activity (in a monomeric, GTP-bound conformation) is to bind aminoacyl-tRNAs and deliver them to the A-site of the 80S ribosome. However, both eEF1A1 and eEF1A2 are endowed with multitasking abilities (sometimes performed by homo- and heterodimers) and can be located in different subcellular compartments, from the plasma membrane to the nucleus. Given the high sequence identity of these two sister proteins and the large number of post-translational modifications they can undergo, we are often confronted with the dilemma of discerning which is the particular proteoform that is actually responsible for the ascribed biochemical or cellular effects. We argue in this review that acquiring this knowledge is essential to help clarify, in molecular and structural terms, the mechanistic involvement of these two ancestral and abundant G proteins in a variety of fundamental cellular processes other than translation elongation. Of particular importance for this special issue is the fact that several de novo heterozygous missense mutations in the human EEF1A2 gene are associated with a subset of rare but severe neurological syndromes and cardiomyopathies.

scholarly journals Targeting the DNA replication stress phenotype of KRAS mutant cancer cells

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tara Al Zubaidi ◽  
O. H. Fiete Gehrisch ◽  
Marie-Michelle Genois ◽  
Qi Liu ◽  
Shan Lu ◽  
...  
Keyword(s):  
Dna Replication ◽  
Single Molecule ◽  
Replication Stress ◽  
Proton Radiation ◽  
Wild Type ◽  
Cellular Effects ◽  
Proton Treatment ◽  
Dna Replication Stress ◽  
Fork Stalling ◽  
Mutant Cells

AbstractMutant KRAS is a common tumor driver and frequently confers resistance to anti-cancer treatments such as radiation. DNA replication stress in these tumors may constitute a therapeutic liability but is poorly understood. Here, using single-molecule DNA fiber analysis, we first characterized baseline replication stress in a panel of unperturbed isogenic and non-isogenic cancer cell lines. Correlating with the observed enhanced replication stress we found increased levels of cytosolic double-stranded DNA in KRAS mutant compared to wild-type cells. Yet, despite this phenotype replication stress-inducing agents failed to selectively impact KRAS mutant cells, which were protected by CHK1. Similarly, most exogenous stressors studied did not differentially augment cytosolic DNA accumulation in KRAS mutant compared to wild-type cells. However, we found that proton radiation was able to slow fork progression and preferentially induce fork stalling in KRAS mutant cells. Proton treatment also partly reversed the radioresistance associated with mutant KRAS. The cellular effects of protons in the presence of KRAS mutation clearly contrasted that of other drugs affecting replication, highlighting the unique nature of the underlying DNA damage caused by protons. Taken together, our findings provide insight into the replication stress response associated with mutated KRAS, which may ultimately yield novel therapeutic opportunities.

scholarly journals Microcystin Toxicokinetics, Molecular Toxicology, and Pathophysiology in Preclinical Rodent Models and Humans

Toxins ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 537
Author(s):  
Tarana Arman ◽  
John D. Clarke
Keyword(s):  
Current Knowledge ◽  
Covalent Binding ◽  
Daily Intake ◽  
Fecal Excretion ◽  
Rodent Models ◽  
Molecular Toxicology ◽  
Cellular Effects ◽  
Specific Distribution ◽  
Liver And Kidney ◽  
Fish And Shellfish

Microcystins are ubiquitous toxins produced by photoautotrophic cyanobacteria. Human exposures to microcystins occur through the consumption of contaminated drinking water, fish and shellfish, vegetables, and algal dietary supplements and through recreational activities. Microcystin-leucine-arginine (MCLR) is the prototypical microcystin because it is reported to be the most common and toxic variant and is the only microcystin with an established tolerable daily intake of 0.04 µg/kg. Microcystin toxicokinetics is characterized by low intestinal absorption, rapid and specific distribution to the liver, moderate metabolism to glutathione and cysteinyl conjugates, and low urinary and fecal excretion. Molecular toxicology involves covalent binding to and inhibition of protein phosphatases, oxidative stress, cell death (autophagy, apoptosis, necrosis), and cytoskeleton disruption. These molecular and cellular effects are interconnected and are commonly observed together. The main target organs for microcystin toxicity are the intestine, liver, and kidney. Preclinical data indicate microcystins may also have nervous, pulmonary, cardiac, and reproductive system toxicities. Recent evidence suggests that exposure to other hepatotoxic insults could potentiate microcystin toxicity and increase the risk for chronic diseases. This review summarizes the current knowledge for microcystin toxicokinetics, molecular toxicology, and pathophysiology in preclinical rodent models and humans. More research is needed to better understand human toxicokinetics and how multifactorial exposures contribute to disease pathogenesis and progression.

scholarly journals A Tale of Ice and Fire: The Dual Role for 17β-Estradiol in Balancing DNA Damage and Genome Integrity

Cancers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1583
Author(s):  
Sara Pescatori ◽  
Francesco Berardinelli ◽  
Jacopo Albanesi ◽  
Paolo Ascenzi ◽  
Maria Marino ◽  
...  
Keyword(s):  
Dna Damage ◽  
Cellular Transformation ◽  
Genome Integrity ◽  
Physiological Effects ◽  
Dna Damages ◽  
Cellular Effects ◽  
Damage Response ◽  
17Β Estradiol ◽  
Cellular Pathways ◽  
Definition Of

17β-estradiol (E2) regulates human physiology both in females and in males. At the same time, E2 acts as a genotoxic substance as it could induce DNA damages, causing the initiation of cellular transformation. Indeed, increased E2 plasma levels are a risk factor for the development of several types of cancers including breast cancer. This paradoxical identity of E2 undermines the foundations of the physiological definition of “hormone” as E2 works both as a homeostatic regulator of body functions and as a genotoxic compound. Here, (i) the molecular circuitries underlying this double face of E2 are reviewed, and (ii) a possible framework to reconcile the intrinsic discrepancies of the E2 function is reported. Indeed, E2 is a regulator of the DNA damage response, which this hormone exploits to calibrate its genotoxicity with its physiological effects. Accordingly, the genes required to maintain genome integrity belong to the E2-controlled cellular signaling network and are essential for the appearance of the E2-induced cellular effects. This concept requires an “upgrade” to the vision of E2 as a “genotoxic hormone”, which balances physiological and detrimental pathways to guarantee human body homeostasis. Deregulation of this equilibrium between cellular pathways would determine the E2 pathological effects.

scholarly journals Cellular Effects of Rhynchophylline and Relevance to Sleep Regulation

2021 ◽  
Vol 3 (2) ◽  
pp. 312-341
Author(s):  
Maria Neus Ballester Roig ◽  
Tanya Leduc ◽  
Cassandra C. Areal ◽  
Valérie Mongrain
Keyword(s):  
Sleep Time ◽  
Sleep Regulation ◽  
Neuronal Communication ◽  
Cellular Effects ◽  
Pathological Conditions ◽  
Extracellular Signal ◽  
Mitogen Activated Protein ◽  
Cellular Pathways ◽  
Phosphoinositide 3 Kinase ◽  
Protein Kinase Akt

Uncaria rhynchophylla is a plant highly used in the traditional Chinese and Japanese medicines. It has numerous health benefits, which are often attributed to its alkaloid components. Recent studies in humans show that drugs containing Uncaria ameliorate sleep quality and increase sleep time, both in physiological and pathological conditions. Rhynchophylline (Rhy) is one of the principal alkaloids in Uncaria species. Although treatment with Rhy alone has not been tested in humans, observations in rodents show that Rhy increases sleep time. However, the mechanisms by which Rhy could modulate sleep have not been comprehensively described. In this review, we are highlighting cellular pathways that are shown to be targeted by Rhy and which are also known for their implications in the regulation of wakefulness and sleep. We conclude that Rhy can impact sleep through mechanisms involving ion channels, N-methyl-d-aspartate (NMDA) receptors, tyrosine kinase receptors, extracellular signal-regulated kinases (ERK)/mitogen-activated protein kinases (MAPK), phosphoinositide 3-kinase (PI3K)/RAC serine/threonine-protein kinase (AKT), and nuclear factor-kappa B (NF-κB) pathways. In modulating multiple cellular responses, Rhy impacts neuronal communication in a way that could have substantial effects on sleep phenotypes. Thus, understanding the mechanisms of action of Rhy will have implications for sleep pharmacology.

scholarly journals Vitamin E beyond Its Antioxidant Label

Antioxidants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 634
Author(s):  
Anca Ungurianu ◽  
Anca Zanfirescu ◽  
Georgiana Nițulescu ◽  
Denisa Margină
Keyword(s):  
Vitamin E ◽  
Signaling Pathways ◽  
Molecular Mechanisms ◽  
Protective Effects ◽  
Cellular Effects ◽  
Inflammatory Status ◽  
Anti Cancer ◽  
Key Factor ◽  
Exciting Potential ◽  
Underlying Mechanisms

Vitamin E, comprising tocopherols and tocotrienols, is mainly known as an antioxidant. The aim of this review is to summarize the molecular mechanisms and signaling pathways linked to inflammation and malignancy modulated by its vitamers. Preclinical reports highlighted a myriad of cellular effects like modulating the synthesis of pro-inflammatory molecules and oxidative stress response, inhibiting the NF-κB pathway, regulating cell cycle, and apoptosis. Furthermore, animal-based models have shown that these molecules affect the activity of various enzymes and signaling pathways, such as MAPK, PI3K/Akt/mTOR, JAK/STAT, and NF-κB, acting as the underlying mechanisms of their reported anti-inflammatory, neuroprotective, and anti-cancer effects. In clinical settings, not all of these were proven, with reports varying considerably. Nonetheless, vitamin E was shown to improve redox and inflammatory status in healthy, diabetic, and metabolic syndrome subjects. The anti-cancer effects were inconsistent, with both pro- and anti-malignant being reported. Regarding its neuroprotective properties, several studies have shown protective effects suggesting vitamin E as a potential prevention and therapeutic (as adjuvant) tool. However, source and dosage greatly influence the observed effects, with bioavailability seemingly a key factor in obtaining the preferred outcome. We conclude that this group of molecules presents exciting potential for the prevention and treatment of diseases with an inflammatory, redox, or malignant component.

scholarly journals Molecular and Cellular Effects of Chemical Chaperone—TUDCA on ER-Stressed NHAC-kn Human Articular Chondrocytes Cultured in Normoxic and Hypoxic Conditions

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 878
Author(s):  
Magdalena Kusaczuk ◽  
Monika Naumowicz ◽  
Rafał Krętowski ◽  
Bartosz Cukierman ◽  
Marzanna Cechowska-Pasko
Keyword(s):  
Er Stress ◽  
Articular Chondrocytes ◽  
Potential Candidate ◽  
Chemical Chaperone ◽  
Cellular Effects ◽  
Chop Expression ◽  
Hypoxic Conditions ◽  
Stressed Cells ◽  
Apoptotic Activity ◽  
Potential Therapeutics

Osteoarthritis (OA) is considered one of the most common arthritic diseases characterized by progressive degradation and abnormal remodeling of articular cartilage. Potential therapeutics for OA aim at restoring proper chondrocyte functioning and inhibiting apoptosis. Previous studies have demonstrated that tauroursodeoxycholic acid (TUDCA) showed anti-inflammatory and anti-apoptotic activity in many models of various diseases, acting mainly via alleviation of endoplasmic reticulum (ER) stress. However, little is known about cytoprotective effects of TUDCA on chondrocyte cells. The present study was designed to evaluate potential effects of TUDCA on interleukin-1β (IL-1β) and tunicamycin (TNC)-stimulated NHAC-kn chondrocytes cultured in normoxic and hypoxic conditions. Our results showed that TUDCA alleviated ER stress in TNC-treated chondrocytes, as demonstrated by reduced CHOP expression; however, it was not effective enough to prevent apoptosis of NHAC-kn cells in either normoxia nor hypoxia. However, co-treatment with TUDCA alleviated inflammatory response induced by IL-1β, as shown by down regulation of Il-1β, Il-6, Il-8 and Cox2, and increased the expression of antioxidant enzyme Sod2. Additionally, TUDCA enhanced Col IIα expression in IL-1β- and TNC-stimulated cells, but only in normoxic conditions. Altogether, these results suggest that although TUDCA may display chondoprotective potential in ER-stressed cells, further analyses are still necessary to fully confirm its possible recommendation as potential candidate in OA therapy.

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