scholarly journals Effect of NaHS on carbonic anhydrase activity of human erythrocyte

2016 ◽  
Vol 7 (3) ◽  
pp. 23-27 ◽  
Author(s):  
Abhijit Bhakta ◽  
Maitreyi Bandyopadhyay ◽  
Sayantan Dasgupta ◽  
Santanu Sen ◽  
Arun Kumar ◽  
...  
Keyword(s):  
Carbonic Anhydrase ◽  
Normal Saline ◽  
Carbonic Anhydrase Activity ◽  
Experimental Models ◽  
Test Tube ◽  
Dependent Manner ◽  
Carbonic Anhydrases ◽  
Medical Sciences ◽  
First Time

Background: In contrast to its role as poison, hydrogen sulfide (H2S) is recently considered as a gaso-transmitter which mediates important physiologic functions in humans. Evidence is accumulating to demonstrate that inhibitors of H2S production or therapeutic H2S donor compounds exert significant effects in various experimental models. Carbonic anhydrases (CA) are a group of zinc-containing metalloenzymes that catalyse the reversible hydration of carbon dioxide. CAs activity in erythrocytes (CAI and CAII) has recently been observed to be associated with various pathological conditions especially in diabetes mellitus, hypertension and lipid disorders. Alteration of this enzyme activity has been reported by the effect of advanced glycation end products methylglyoxal and reduced glutathione.   Aims and Objectives: As H2S, being a mediator of many physiological functions and synthesized in vivo, may affect functions of many intracellular proteins like carbonic anhydrase, the objective of this study is to find out if there is any change in the carbonic anhydrase activity under the effect of H2S- donor NaHS in dose dependant manner using RBC model in vitro.Materials and Methods: Blood sample was collected from forty (40) numbers of healthy volunteers of 18-40 years of in heparin containing vials and packed cells were prepared immediately by centrifugation  The packed erythrocytes were washed three times with normal saline and  diluted (1:10) with the normal saline. One ml each of diluted packed cells was taken in eight test tubes. Serial dilutions of NaHS (1to 250 µMol/L) was added to all the test tubes except for the first test tube where only normal saline was added and   incubated at room temperature for one hour. Haemolysates was prepared from the erythrocytes with equal volume of distilled water in each tube and the CA activity was determined in the haemolysates using standardized method.Results: There is significant increase of CA activity in dose dependent manner under the effect of NaHS and also compared to the activity of hemolysate prepared without NaHS.  Conclusions:Our study for the first time demonstrated that the Carbonic Anhydrase activity of erythrocytes is significantly increases by the effect of NaHS and this study reveals some important biological role of H2S and carbonic anhydrase.Asian Journal of Medical Sciences Vol. 7(3) 2016 23-27

scholarly journals Functional involvement of carbonic anhydrase in calcium transport of the chick chorioallantoic membrane

1978 ◽  
Vol 176 (1) ◽  
pp. 67-74 ◽  
Author(s):  
R S Tuan ◽  
J Zrike
Keyword(s):  
Carbonic Anhydrase ◽  
Chorioallantoic Membrane ◽  
Carbonic Anhydrase Activity ◽  
Calcium Deposition ◽  
Dependent Manner ◽  
Transport Activity ◽  
In Ovo ◽  
Chick Chorioallantoic Membrane ◽  
Age Dependent

Carbonic anhydrase activity was demonstrated in the chick-embryonic chorioallantoic membrane and was correlated with the Ca2+-transport activity of the membrane. It is inhibited by sulphonamides and is expressed in the chorioallantoic membrane in an age-dependent fashion during embryonic development. Ca2+ uptake by the chorioallantoic membrane in vivo also increases in a similar age-dependent manner. The temporal increase in these activities is coincident with calcium deposition in the embryonic skeleton. Incubation of the chorioallantoic membrane in ovo with sulphonamides specifically inhibits both the carbonic anhydrase and the Ca2+ uptake activities of the membrane in vivo. Enzyme histochemistry revealed the carbonic anhydrase activity is localized in the Ca2+-transporting ectodermal cells of the chorioallantoic membrane. These results, taken together, indicate that carbonic anhydrase may be functionally important in the Ca2+-transport activity of the chorioallantoic membrane.

scholarly journals Flow-dependent regulation of endothelial Tie2 by GATA3 in vivo

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Temitayo O. Idowu ◽  
Valerie Etzrodt ◽  
Thorben Pape ◽  
Joerg Heineke ◽  
Klaus Stahl ◽  
...  
Keyword(s):  
Gene Expression ◽  
Regulation Of Gene Expression ◽  
Experimental Models ◽  
Common Denominator ◽  
Dependent Manner ◽  
Pulmonary Endothelium ◽  
Delivery Platform ◽  
Transient Overexpression ◽  
Plasmid Delivery

Abstract Background Reduced endothelial Tie2 expression occurs in diverse experimental models of critical illness, and experimental Tie2 suppression is sufficient to increase spontaneous vascular permeability. Looking for a common denominator among different critical illnesses that could drive the same Tie2 suppressive (thereby leak inducing) phenotype, we identified “circulatory shock” as a shared feature and postulated a flow-dependency of Tie2 gene expression in a GATA3 dependent manner. Here, we analyzed if this mechanism of flow-regulation of gene expression exists in vivo in the absence of inflammation. Results To experimentally mimic a shock-like situation, we developed a murine model of clonidine-induced hypotension by targeting a reduced mean arterial pressure (MAP) of approximately 50% over 4 h. We found that hypotension-induced reduction of flow in the absence of confounding disease factors (i.e., inflammation, injury, among others) is sufficient to suppress GATA3 and Tie2 transcription. Conditional endothelial-specific GATA3 knockdown (B6-Gata3tm1-Jfz VE-Cadherin(PAC)-cerERT2) led to baseline Tie2 suppression inducing spontaneous vascular leak. On the contrary, the transient overexpression of GATA3 in the pulmonary endothelium (jet-PEI plasmid delivery platform) was sufficient to increase Tie2 at baseline and completely block its hypotension-induced acute drop. On the functional level, the Tie2 protection by GATA3 overexpression abrogated the development of pulmonary capillary leakage. Conclusions The data suggest that the GATA3–Tie2 signaling pathway might play a pivotal role in controlling vascular barrier function and that it is affected in diverse critical illnesses with shock as a consequence of a flow-regulated gene response. Targeting this novel mechanism might offer therapeutic opportunities to treat vascular leakage of diverse etiologies.

scholarly journals Secreted KIAA1199 promotes the progression of rheumatoid arthritis by mediating hyaluronic acid degradation in an ANXA1-dependent manner

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Wei Zhang ◽  
Guoyu Yin ◽  
Heping Zhao ◽  
Hanzhi Ling ◽  
Zhen Xie ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Hyaluronic Acid ◽  
Dependent Manner ◽  
Collagen Induced Arthritis ◽  
Intracellular Degradation ◽  
Main Pathway ◽  
First Time

AbstractIn inflamed joints, enhanced hyaluronic acid (HA) degradation is closely related to the pathogenesis of rheumatoid arthritis (RA). KIAA1199 has been identified as a hyaladherin that mediates the intracellular degradation of HA, but its extracellular function remains unclear. In this study, we found that the serum and synovial levels of secreted KIAA1199 (sKIAA1199) and low-molecular-weight HA (LMW-HA, MW < 100 kDa) in RA patients were significantly increased, and the positive correlation between them was shown for the first time. Of note, treatment with anti-KIAA1199 mAb effectively alleviated the severity of arthritis and reduced serum LMW-HA levels and cytokine secretion in collagen-induced arthritis (CIA) mice. In vitro, sKIAA1199 was shown to mediate exogenous HA degradation by attaching to the cell membrane of RA fibroblast-like synoviosytes (RA FLS). Furthermore, the HA-degrading activity of sKIAA1199 depended largely on its adhesion to the membrane, which was achieved by its G8 domain binding to ANXA1. In vivo, kiaa1199-KO mice exhibited greater resistance to collagen-induced arthritis. Interestingly, this resistance could be partially reversed by intra-articular injection of vectors encoding full-length KIAA1199 instead of G8-deleted KIAA119 mutant, which further confirmed the indispensable role of G8 domain in KIAA1199 involvement in RA pathological processes. Mechanically, the activation of NF-κB by interleukin-6 (IL-6) through PI3K/Akt signaling is suggested to be the main pathway to induce KIAA1199 expression in RA FLS. In conclusion, our study supported the contribution of sKIAA1199 to RA pathogenesis, providing a new therapeutic target for RA by blocking sKIAA1199-mediated HA degradation.

scholarly journals Polymorphisms in Brucella Carbonic anhydrase II mediate CO2 dependence and fitness in vivo

2019 ◽  
Author(s):  
JM García-Lobo ◽  
Y Ortiz ◽  
C González-Riancho ◽  
A Seoane ◽  
B Arellano-Reynoso ◽  
...  
Keyword(s):  
Carbonic Anhydrase ◽  
Primary Cultures ◽  
Low Frequency ◽  
Carbonic Anhydrase Ii ◽  
Carbonic Anhydrases ◽  
Significant Difference ◽  
Dependent Strain

AbstractSome Brucella isolates are known to require an increased concentration of CO2 for growth, especially in the case of primary cultures obtained directly from infected animals. Moreover, the different Brucella species and biovars show a characteristic pattern of CO2 requirement, and this trait has been included among the routine typing tests used for species and biovar differentiation. By comparing the differences in gene content among different CO2-dependent and CO2-independent Brucella strains we have confirmed that carbonic anhydrase II (CA II), is the enzyme responsible for this phenotype in all the Brucella strains tested. Brucella species contain two carbonic anhydrases of the β family, CA I and CA II; genetic polymorphisms exist for both of them in different isolates, but only those putatively affecting the activity of CA II correlate with the CO2 requirement of the corresponding isolate. Analysis of these polymorphisms does not allow the determination of CA I functionality, while the polymorphisms in CA II consist of small deletions that cause a frameshift that changes the C-terminus of the protein, probably affecting its dimerization status, essential for the activity.CO2-independent mutants arise easily in vitro, although with a low frequency ranging from 10−6 to 10−10 depending on the strain. These mutants carry compensatory mutations that produce a full length CA II. At the same time, no change was observed in the sequence coding for CA I. A competitive index assay designed to evaluate the fitness of a CO2-dependent strain compared to its corresponding CO2-independent strain revealed that while there is no significant difference when the bacteria are grown in culture plates, growth in vivo in a mouse model of infection provides a significant advantage to the CO2-dependent strain. This could explain why some Brucella isolates are CO2-dependent in primary isolation. The polymorphism described here also allows the in silico determination of the CO2 requirement status of any Brucella strain.

scholarly journals INTEGRINS MEDIATE PLACENTAL EXTRACELLULAR VESICLE TRAFFICKING TO LUNG AND LIVER IN VIVO

2020 ◽  
Author(s):  
Sean L. Nguyen ◽  
Soo Hyun Ahn ◽  
Jacob W. Greenberg ◽  
Benjamin W. Collaer ◽  
Dalen W. Agnew ◽  
...  
Keyword(s):  
Immune Cells ◽  
Extracellular Vesicle ◽  
Dependent Manner ◽  
Cellular Phenotype ◽  
Reporter Mouse ◽  
Membrane Bound ◽  
First Time

ABSTRACTMembrane-bound extracellular vesicles (EVs) mediate intercellular communication in all organisms, and those produced by placental mammals have become increasingly recognized as significant mediators of fetal-maternal communication. Here, we aimed to identify maternal cells targeted by placental EVs and elucidate the mechanisms by which they traffic to these cells. Exogenously administered pregnancy-associated EVs traffic specifically to the lung; further, placental EVs associate with lung interstitial macrophages and liver Kupffer cells in an integrin-dependent manner. Localization of EV to maternal lungs was confirmed in unmanipulated pregnancy using a transgenic reporter mouse model, which also provided in situ and in vitro evidence that fetally-derived EVs, rarely, may cause genetic alteration of maternal cells. These results provide for the first time direct in vivo evidence for targeting of placental EVs to maternal immune cells, and further, evidence that EVs can alter cellular phenotype.

Carbonic anhydrase in the midgut of larvalAedes aegypti: cloning, localization and inhibition

2002 ◽  
Vol 205 (5) ◽  
pp. 591-602 ◽  
Author(s):  
Maria del Pilar Corena ◽  
Theresa J. Seron ◽  
Herm K. Lehman ◽  
Judith D. Ochrietor ◽  
Andrea Kohn ◽  
...  
Keyword(s):  
Carbonic Anhydrase ◽  
Aedes Aegypti ◽  
Fruit Fly ◽  
Cellular Heterogeneity ◽  
Carbonic Anhydrases ◽  
Larval Midgut ◽  
Posterior Midgut

SUMMARYThe larval mosquito midgut exhibits one of the highest pH values known in a biological system. While the pH inside the posterior midgut and gastric caeca ranges between 7.0 and 8.0, the pH inside the anterior midgut is close to 11.0. Alkalization is likely to involve bicarbonate/carbonate ions. These ions are produced in vivo by the enzymatic action of carbonic anhydrase. The purpose of this study was to investigate the role of this enzyme in the alkalization mechanism, to establish its presence and localization in the midgut of larval Aedes aegypti and to clone and characterize its cDNA. Here, we report the physiological demonstration of the involvement of carbonic anhydrase in midgut alkalization. Histochemistry and in situ hybridization showed that the enzyme appears to be localized throughout the midgut, although preferentially in the gastric caeca and posterior regions with specific cellular heterogeneity. Furthermore, we report the cloning and localization of the first carbonic anhydrase from mosquito larval midgut. A cDNA clone from Aedes aegypti larval midgut revealed sequence homology to α-carbonic anhydrases from vertebrates. Bioinformatics indicates the presence of at least six carbonic anhydrases or closely related genes in the genome of another dipteran, the fruit fly Drosophila melanogaster. Molecular analyses suggest that the larval mosquito may also possess multiple forms.

scholarly journals Inhibition of FGF2-Mediated Signaling in GIST—Promising Approach for Overcoming Resistance to Imatinib

Cancers ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1674
Author(s):  
Sergei Boichuk ◽  
Aigul Galembikova ◽  
Ekaterina Mikheeva ◽  
Firuza Bikinieva ◽  
Aida Aukhadieva ◽  
...  
Keyword(s):  
Tumor Response ◽  
Molecular Target ◽  
Compensatory Mechanism ◽  
Dependent Manner ◽  
First Line ◽  
Induced Apoptosis ◽  
First Time ◽  
Malignant Behavior ◽  
First Line Treatment

Inhibition of KIT-signaling is a major molecular target for gastrointestinal stromal tumor (GIST) therapy, and imatinib mesylate (IM) is known as the most effective first-line treatment option for patients with advanced, unresectable, and/or metastatic GISTs. We show here for the first time that the inhibition of KIT-signaling in GISTs induces profound changes in the cellular secretome, leading to the release of multiple chemokines, including FGF-2. IM increased migration, invasion, and colony formation of IM-resistant GISTs in an FGF2-dependent manner, whereas the use of blocking anti-FGF2 antibodies or BGJ398, a selective FGFR inhibitor, abolished these effects, thus suggesting that the activation of FGF2-mediated signaling could serve as a compensatory mechanism of KIT-signaling inhibited in GISTs. Conversely, FGF-2 rescued the growth of IM-naive GISTs treated by IM and protected them from IM-induced apoptosis, consistent with the possible involvement of FGF-2 in tumor response to IM-based therapy. Indeed, increased FGF-2 levels in serum and tumor specimens were found in IM-treated mice bearing IM-resistant GIST xenografts, whereas BGJ398 used in combination with IM effectively inhibited their growth. Similarly, increased FGF-2 expression in tumor specimens from IM-treated patients revealed the activation of FGF2-signaling in GISTs in vivo. Collectively, the continuation of IM-based therapy for IM-resistant GISTs might facilitate disease progression by promoting the malignant behavior of tumors in an FGF2-dependent manner. This provides a rationale to evaluate the effectiveness of the inhibitors of FGF-signaling for IM-resistant GISTs.

scholarly journals The Carbonic Anhydrase Inhibitor Ethoxzolamide Inhibits the Mycobacterium tuberculosis PhoPR Regulon and Esx-1 Secretion and Attenuates Virulence

2015 ◽  
Vol 59 (8) ◽  
pp. 4436-4445 ◽  
Author(s):  
Benjamin K. Johnson ◽  
Christopher J. Colvin ◽  
David B. Needle ◽  
Felix Mba Medie ◽  
Patricia A. DiGiuseppe Champion ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Carbonic Anhydrase ◽  
Regulatory System ◽  
Carbonic Anhydrase Activity ◽  
Carbonic Anhydrase Inhibitor ◽  
Fluorescent Reporter ◽  
Content Type ◽  
Pathogen Virulence ◽  
Mutant Phenotypes

ABSTRACTMycobacterium tuberculosismust sense and adapt to host environmental cues to establish and maintain an infection. The two-component regulatory system PhoPR plays a central role in sensing and responding to acidic pH within the macrophage and is required forM. tuberculosisintracellular replication and growthin vivo. Therefore, the isolation of compounds that inhibit PhoPR-dependent adaptation may identify new antivirulence therapies to treat tuberculosis. Here, we report that the carbonic anhydrase inhibitor ethoxzolamide inhibits the PhoPR regulon and reduces pathogen virulence. We show that treatment ofM. tuberculosiswith ethoxzolamide recapitulatesphoPRmutant phenotypes, including downregulation of the core PhoPR regulon, altered accumulation of virulence-associated lipids, and inhibition of Esx-1 protein secretion. Quantitative single-cell imaging of a PhoPR-dependent fluorescent reporter strain demonstrates that ethoxzolamide inhibits PhoPR-regulated genes in infected macrophages and mouse lungs. Moreover, ethoxzolamide reducesM. tuberculosisgrowth in both macrophages and infected mice. Ethoxzolamide inhibitsM. tuberculosiscarbonic anhydrase activity, supporting a previously unrecognized link between carbonic anhydrase activity and PhoPR signaling. We propose that ethoxzolamide may be pursued as a new class of antivirulence therapy that functions by modulating expression of the PhoPR regulon and Esx-1-dependent virulence.

A phase I clinical study of safingol followed by cisplatin: promising activity in refractory adrenocortical cancer with novel pharmacology

2006 ◽  
Vol 24 (18_suppl) ◽  
pp. 13044-13044 ◽  
Author(s):  
R. D. Carvajal ◽  
A. H. Merrill ◽  
H. Dials ◽  
A. Barbi ◽  
G. K. Schwartz
Keyword(s):  
Phase I ◽  
Sphingosine Kinase ◽  
Competitive Inhibitor ◽  
Fixed Dose ◽  
Dependent Manner ◽  
Adrenocortical Cancer ◽  
Kinase C ◽  
Human Blood Cells ◽  
First Time

13044 Background: Safingol (L-threo-dihydrosphingosine), originally identified as a competitive inhibitor of protein kinase C, has been re-identified as an inhibitor of sphingosine kinase (SK). Inhibition of SK induces apotosis and autophagy by increasing intracellular conversion of sphingosine to ceramide. In vivo, safingol enhances the antitumor activity of cisplatin in a sequence dependent manner (safingol→cisplatin). Methods: We designed a phase I trial of escalating doses of safingol (60→120→240→ 360→480→600 mg/m2) followed 1 hr later by fixed-dose cisplatin 75 mg/m2 given q21 days in pts with advanced solid tumors. Standard phase I eligibility critieria apply. Prior cisplatin is allowed. Results: 13 evaluable pts have been enrolled: 5 male/8 female, median age 54 (range 36–68), median KPS 90% (range 80–100%), mean number of priors 2.8 (range 1–6). 2 dose limiting toxicities (DLT) were observed with escalation of safingol to 240 mg/m2 (gr 3 fatigue, gr 3 hyponatremia), both felt to be due primarily to cisplatin. The protocol was amended to reduce cisplatin to 60 mg/m2, given with 240 mg/m2 of safingol. We observed 1 DLT (persistent gr 3 thrombocytopenia) at this dose level. Pharmacokinetic (PK) analysis by mass spectroscopy shows nearly complete clearance of safingol from circulation within 24 hours of treatment with a 10-fold greater amount of safingol in whole blood than in plasma. An increase in sphingosine and dihydroceramide levels were observed with therapy, and N-acyl- and N-methyl- metabolites of safingol were detected. We observed 1 PR (4+ months) in a pt with cisplatin-refractory adrenocortical cancer metastatic to the liver and lung after only 1 cycle of therapy. 1 additional pt with adrenocortical cancer has SD (2+ months) on therapy. Conclusions: Escalating doses of safingol can be safely administered with a fixed dose of cisplatin. PK data reveal acyl- and methyl-safingol for the first time in human plasma, with a significant fraction of safingol bound to human blood cells. We observed unusual activity in pts with adrenocortical cancer. Further dose escalation of safingol with cisplatin 60 mg/m2 is ongoing, and additional PK data and complete sphingolipid profiles will be presented. (Supported by NCI R21-CA112910). No significant financial relationships to disclose.

scholarly journals Hydroxyl radical induced structural changes of collagen

2007 ◽  
Vol 21 (2) ◽  
pp. 91-103 ◽  
Author(s):  
Helan Xiao ◽  
Guoping Cai ◽  
Mingyao Liu
Keyword(s):  
Free Radical ◽  
Hydroxyl Radicals ◽  
Structural Changes ◽  
Type I Collagen ◽  
Free Radical Scavenger ◽  
Radical Scavenger ◽  
Type I ◽  
Dependent Manner ◽  
First Time

Extracellular matrix (ECM) plays an important role in cell differentiation, growth, migration and apoptosis. Collagen is the most abundant protein familyin vivo, but its function has still not been clearly defined yet. Reactive oxygen species (ROS) have a central role in oxidative cell stress. Electron spin resonance (ESR) spectroscopy indicates that type I collagen could uniquely scavenge hydroxyl radicals in dose- and time-dependent manner; whereas BSA and gelatin (a denatured collagen) have no such an effect. However, the mechanism by which type I collagen scavenges hydroxyl radicals is different from that of GSH, a well-known free radical scavenger. Using a new method, two-dimensional FTIR correlation analysis, for the first time, we show that the order of functional group changes of type I collagen in this process is amide I earlier than amide II than amide III than –CH– thanν(C=O). The results indicates that the structure of the main chain of collagen changed first, followed by more residue groupν(C=O) exposed to hydroxyl radicals. The reaction with the carbonyl group in collagen causes the hydroxyl free radicals to be scavenged. Therefore, ECM can effectively scavenge ROS under normal physiological conditions. When the proteins of ECM were denatured in the same way as gelatin, they lost their function as a free radical scavenger. All of these results provide new insight into therapy or prevention of oxidative stress, apoptosis and ageing.

Sign in / Sign up

Export Citation Format

Share Document