scholarly journals Role of OATP4C1 in Renal Handling of Remdesivir and its Nucleoside Analog GS-441524: The First Approved Drug for Patients with COVID-19

2021 ◽  
Vol 24 ◽  
pp. 227-236
Author(s):  
Toshihiro Sato ◽  
Masamitsu Maekawa ◽  
Nariyasu Mano ◽  
Takaaki Abe ◽  
Hiroaki Yamaguchi
Keyword(s):  
Kidney Injury ◽  
Nucleoside Analog ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Renal Handling ◽  
Mdckii Cells ◽  
Proximal Tubular ◽  
Handling Methods ◽  
Uptake Transporters

Purpose. Remdesivir and its active metabolite are predominantly eliminated via renal route; however, information regarding renal uptake transporters is limited. In the present study, the interaction of remdesivir and its nucleoside analog GS-441524 with OATP4C1 was evaluated to provide the detailed information about its renal handling. Methods. We used HK-2 cells, a proximal tubular cell line derived from normal kidney, to confirm the transport of remdesivir and GS-441524. To assess the involvement of OATP4C1 in handling remdesivir and GS-441524, the uptake study of remdesivir and GS-441524 was performed by using OATP4C1-overexpressing Madin-Darby canine kidney II (MDCKII) cells. Moreover, we also evaluated the IC50 and Ki value of remdesivir. Results. The time-dependent remdesivir uptake in HK-2 cells was observed. The results of inhibition study using OATs and OCT2 inhibitors and OATP4C1 knockdown suggested the involvement of renal drug transporter OATP4C1. Remdesivir was taken up by OATP4C1/MDCKII cells. OATP4C1-mediated uptake of remdesivir increased linearly up to 10 min and reached a steady state at 30 min. Remdesivir inhibited OATP4C1-mediated transport in a concentration-dependent manner with the IC50 and apparent Ki values of 42 ± 7.8 μM and 37 ± 6.9 μM, respectively. Conclusions. We have provided novel information about renal handling of remdesivir. Furthermore, we evaluated the potential drug interaction via OATP4C1 by calculating the Ki value of remdesivir. OATP4C1 may play a pivotal role in remdesivir therapy for COVID-19, particularly in patients with kidney injury.  

scholarly journals Delayed treatment with fenofibrate protects against high-fat diet-induced kidney injury in mice: the possible role of AMPK autophagy

2017 ◽  
Vol 312 (2) ◽  
pp. F323-F334 ◽  
Author(s):  
Minji Sohn ◽  
Keumji Kim ◽  
Md Jamal Uddin ◽  
Gayoung Lee ◽  
Inah Hwang ◽  
...  
Keyword(s):  
High Fat Diet ◽  
Kidney Injury ◽  
Acid Oxidation ◽  
Peroxisome Proliferator ◽  
Dependent Manner ◽  
High Fat ◽  
Concentration Dependent Manner ◽  
Delayed Treatment ◽  
Compound C

Fenofibrate activates not only peroxisome proliferator-activated receptor-α (PPARα) but also adenosine monophosphate-activated protein kinase (AMPK). AMPK-mediated cellular responses protect kidney from high-fat diet (HFD)-induced injury, and autophagy resulting from AMPK activation has been regarded as a stress-response mechanism. Thus the present study examined the role of AMPK and autophagy in the renotherapeutic effects of fenofibrate. C57BL/6J mice were divided into three groups: normal diet (ND), HFD, and HFD + fenofibrate (HFD + FF). Fenofibrate was administered 4 wk after the initiation of the HFD when renal injury was initiated. Mouse proximal tubule cells (mProx24) were used to clarify the role of AMPK. Feeding mice with HFD for 12 wk induced insulin resistance and kidney injury such as albuminuria, glomerulosclerosis, tubular injury, and inflammation, which were effectively inhibited by fenofibrate. In addition, fenofibrate treatment resulted in the activation of renal AMPK, upregulation of fatty acid oxidation (FAO) enzymes and antioxidants, and induction of autophagy in the HFD mice. In mProx24 cells, fenofibrate activated AMPK in a concentration-dependent manner, upregulated FAO enzymes and antioxidants, and induced autophagy, all of which were inhibited by treatment of compound C, an AMPK inhibitor. Fenofibrate-induced autophagy was also significantly blocked by AMPKα1 siRNA but not by PPARα siRNA. Collectively, these results demonstrate that delayed treatment with fenofibrate has a therapeutic effect on HFD-induced kidney injury, at least in part, through the activation of AMPK and induction of subsequent downstream effectors: autophagy, FAO enzymes, and antioxidants.

The P-element-induced silencing effect of KP transposons is dose dependent in Drosophila melanogaster

Genome ◽  
2011 ◽  
Vol 54 (9) ◽  
pp. 752-762 ◽  
Author(s):  
Alireza Sameny ◽  
John Locke
Keyword(s):  
Drosophila Melanogaster ◽  
Critical Role ◽  
Mutagenic Effect ◽  
P Element ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
P Elements ◽  
Single Well ◽  
Dose Dependent

Transposable elements are found in the genomes of all eukaryotes and play a critical role in altering gene expression and genome organization. In Drosophila melanogaster, transposable P elements are responsible for the phenomenon of hybrid dysgenesis. KP elements, a deletion-derivative of the complete P element, can suppress this mutagenic effect. KP elements can also silence the expression of certain other P-element-mediated transgenes in a process called P-element-dependent silencing (PDS), which is thought to involve the recruitment of heterochromatin proteins. To explore the mechanism of this silencing, we have mobilized KP elements to create a series of strains that contain single, well-defined KP insertions that show PDS. To understand the quantitative role of KP elements in PDS, these single inserts were combined in a series of crosses to obtain genotypes with zero, one, or two KP elements, from which we could examine the effect of KP gene dose. The extent of PDS in these genotypes was shown to be dose dependent in a logarithmic rather than linear fashion. A logarithmic dose dependency is consistent with the KP products interacting with heterochromatic proteins in a concentration-dependent manner such that two molecules are needed to induce gene silencing.

Protein kinase C potentiates cAMP-stimulated mouse duodenal mucosal bicarbonate secretion in vitro

2004 ◽  
Vol 286 (5) ◽  
pp. G814-G821 ◽  
Author(s):  
Bi-Guang Tuo ◽  
Jimmy Y. C. Chow ◽  
Kim E. Barrett ◽  
Jon I. Isenberg
Keyword(s):  
Short Circuit ◽  
Short Circuit Current ◽  
Duodenal Mucosa ◽  
Bicarbonate Secretion ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Ussing Chambers ◽  
Duodenal Bicarbonate Secretion

PKC has been shown to regulate epithelial Cl- secretion in a variety of models. However, the role of PKC in duodenal mucosal bicarbonate secretion is less clear. We aimed to investigate the role of PKC in regulation of duodenal mucosal bicarbonate secretion. Bicarbonate secretion by murine duodenal mucosa was examined in vitro in Ussing chambers using a pH-stat technique. PKC isoform expression and activity were assessed by Western blotting and in vitro kinase assays, respectively. PMA (an activator of PKC) alone had no effect on duodenal bicarbonate secretion or short-circuit current ( Isc). When PMA and dibutyryl-cAMP (db-cAMP) were added simultaneously, PMA failed to alter db-cAMP-stimulated duodenal bicarbonate secretion or Isc ( P > 0.05). However, a 1-h preincubation with PMA potentiated db-cAMP-stimulated duodenal bicarbonate secretion and Isc in a concentration-dependent manner (from 10-8 to 10-5M) ( P < 0.05). PMA preincubation had no effects on carbachol- or heat-stable toxin-stimulated bicarbonate secretion. Western blot analysis revealed that PKCα, -γ, -ϵ, -θ, -μ, and -ι/λ were expressed in murine duodenal mucosa. Ro 31–8220 (an inhibitor active against PKCϵ, -α, -β, and -γ), but not Gö 6983 (an inhibitor active against PKCα, -γ, -β, and -δ), reversed the potentiating effect of PMA on db-cAMP-stimulated bicarbonate secretion. PMA also time- and concentration-dependently increased the activity of PKCϵ, an effect that was prevented by Ro 31–8220 but not Gö 6983. These results demonstrate that activation of PKC potentiates cAMP-stimulated duodenal bicarbonate secretion, whereas it does not modify basal secretion. The effect of PKC on cAMP-stimulated bicarbonate secretion is mediated by the PKCϵ isoform.

scholarly journals Sec1p directly stimulates SNARE-mediated membrane fusion in vitro

2004 ◽  
Vol 167 (1) ◽  
pp. 75-85 ◽  
Author(s):  
Brenton L. Scott ◽  
Jeffrey S. Van Komen ◽  
Hassan Irshad ◽  
Song Liu ◽  
Kirilee A. Wilson ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Membrane Fusion ◽  
Membrane Trafficking ◽  
Snare Complex ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Bud Neck ◽  
Precise Role

Sec1 proteins are critical players in membrane trafficking, yet their precise role remains unknown. We have examined the role of Sec1p in the regulation of post-Golgi secretion in Saccharomyces cerevisiae. Indirect immunofluorescence shows that endogenous Sec1p is found primarily at the bud neck in newly budded cells and in patches broadly distributed within the plasma membrane in unbudded cells. Recombinant Sec1p binds strongly to the t-SNARE complex (Sso1p/Sec9c) as well as to the fully assembled ternary SNARE complex (Sso1p/Sec9c;Snc2p), but also binds weakly to free Sso1p. We used recombinant Sec1p to test Sec1p function using a well-characterized SNARE-mediated membrane fusion assay. The addition of Sec1p to a traditional in vitro fusion assay moderately stimulates fusion; however, when Sec1p is allowed to bind to SNAREs before reconstitution, significantly more Sec1p binding is detected and fusion is stimulated in a concentration-dependent manner. These data strongly argue that Sec1p directly stimulates SNARE-mediated membrane fusion.

scholarly journals Renalase and Biomarkers of Contrast-Induced Acute Kidney Injury

2015 ◽  
Vol 6 (1) ◽  
pp. 25-36 ◽  
Author(s):  
Maciej T. Wybraniec ◽  
Katarzyna Mizia-Stec
Keyword(s):  
Acute Kidney Injury ◽  
Renal Injury ◽  
Amine Oxidase ◽  
Kidney Injury ◽  
Cardiorenal Syndrome ◽  
Creatinine Concentration ◽  
Invasive Cardiology ◽  
Proximal Tubular ◽  
Novel Biomarkers

Background: Contrast-induced acute kidney injury (CI-AKI) remains one of the crucial issues related to the development of invasive cardiology. The massive use of contrast media exposes patients to a great risk of contrast-induced nephropathy and chronic kidney disease development, and increases morbidity and mortality rates. The serum creatinine concentration does not allow for a timely and accurate CI-AKI diagnosis; hence numerous other biomarkers of renal injury have been proposed. Renalase, a novel catecholamine-metabolizing amine oxidase, is synthesized mainly in proximal tubular cells and secreted into urine and blood. It is primarily engaged in the degradation of circulating catecholamines. Notwithstanding its key role in blood pressure regulation, renalase remains a potential CI-AKI biomarker, which was shown to be markedly downregulated in the aftermath of renal injury. In this sense, renalase appears to be the first CI-AKI marker revealing an actual loss of renal function and indicating disease severity. Summary: The purpose of this review is to summarize the contemporary knowledge about the application of novel biomarkers of CI-AKI and to highlight the potential role of renalase as a functional marker of contrast-induced renal injury. Key Messages: Renalase may constitute a missing biochemical link in the mutual interplay between kidney and cardiac pathology known as the cardiorenal syndrome.

scholarly journals Effect of Palmitic Acid on Exosome-Mediated Secretion and Invasive Motility in Prostate Cancer Cells

Molecules ◽  
2020 ◽  
Vol 25 (12) ◽  
pp. 2722
Author(s):  
Ivan V. Maly ◽  
Wilma A. Hofmann
Keyword(s):  
Prostate Cancer ◽  
Palmitic Acid ◽  
Cancer Cells ◽  
Dependent Manner ◽  
Prostate Cancer Cells ◽  
Concentration Dependent Manner ◽  
Fat Consumption ◽  
Progression Markers

High fat consumption can enhance metastasis and decrease survival in prostate cancer, but the picture remains incomplete on the epidemiological and cell-biological level, impeding progress toward individualized recommendations in the clinic. Recent work has highlighted the role of exosomes secreted by prostate cancer cells in the progression of the disease, particularly in metastatic invasion, and also the utility of targeting these extracellular vesicles for diagnostics, as carriers of disease progression markers. Here, we investigated the question of a potential impact of the chief nutritional saturated fatty acid on the exosome secretion. Palmitic acid decreased the secretion of exosomes in human prostate cancer cells in vitro in a concentration-dependent manner. At the same time, the content of some prospective metastatic markers in the secreted exosomal fraction was also reduced, as was the ability of the cells to invade across extracellular matrix barriers. While by themselves our in vitro results imply that on the cell level, palmitic acid may be beneficial vis-à-vis the course of the disease, they also suggest that, by virtue of the decreased biomarker secretion, palmitic acid has the potential to cause unjustified deprioritization of treatment in obese and lipidemic men.

The Role Of Calcium In Platelet Microtubule Assembly- Disassembly

1981 ◽  
Author(s):  
M Kikuchi ◽  
Y Ikeda ◽  
M Handa ◽  
S Matsuda ◽  
H Muraki ◽  
...  
Keyword(s):  
Intracellular Calcium ◽  
Dynamic Equilibrium ◽  
Platelet Rich Plasma ◽  
Human Platelets ◽  
Microtubule Assembly ◽  
Base Line ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Transient Decrease

Microtubules exist in a dynamic equilibrium between polymerized and depolymerized forms in human platelets, playing a major role to maintain the discoid shape of platelets. It has been previously shown that the interaction of aggregating agents with platelets leads to a rapid but transient disassembly of microtubules. ( Steiner and Ikeda, J.Clin. Invest. 63:443,1979 ) In this paper, the role of calcium in the equilibrium between assembled and disassembled microtubules was investigated. The respective pools of soluble and polymerized tubulin were “frozen” by addition of a glycerol-dimethyl sulfoxide-containing medium to platelet rich plasma, preincubated with 2 µM A23187 for various time intervals. The two pools of tubulin were estimated by measuring the colchicine binding activities of total and polymerized tubulin according to the method of Wilson.Resting platelets were found to contain 56.2 ± 2.7 µg tubulin per 109 platelets, of which 56.7 % was in polymerized form. Addition of A23187 to platelet rich plasma produced a transient decrease in the pool of polymerized tubulin within 30 sec., followed by a return to base-line values within 2 min.. TMB-8, a known intracellular calcium antagonist, abolished this transient decrease in polymerized tubulin induced by A23187 in a concentration dependent manner, while indomethacin or acetylsalycylic acid did not.These findings may indicate the important role of intracellular calcium in microtubule assembly-disassembly.

Oxidation of ubiquinol by peroxynitrite: implications for protection of mitochondria against nitrosative damage

2000 ◽  
Vol 349 (1) ◽  
pp. 35-42 ◽  
Author(s):  
Francisco SCHÖPFER ◽  
Natalia RIOBÓ ◽  
María Cecilia CARRERAS ◽  
Beatriz ALVAREZ ◽  
Rafael RADI ◽  
...  
Keyword(s):  
Radical Scavenging ◽  
Redox Status ◽  
Experimental Models ◽  
Dependent Manner ◽  
Mitochondrial Membranes ◽  
Concentration Dependent Manner ◽  
Major Pathway ◽  
Membrane Bound ◽  
Spectroscopy Studies

A major pathway of nitric oxide utilization in mitochondria is its conversion to peroxynitrite, a species involved in biomolecule damage via oxidation, hydroxylation and nitration reactions. In the present study the potential role of mitochondrial ubiquinol in protecting against peroxynitrite-mediated damage is examined and the requirements of the mitochondrial redox status that support this function of ubiquinol are established. (1) Absorption and EPR spectroscopy studies revealed that the reactions involved in the ubiquinol/peroxynitrite interaction were first-order in peroxynitrite and zero-order in ubiquinol, in agreement with the rate-limiting formation of a reactive intermediate formed during the isomerization of peroxynitrite to nitrate. Ubiquinol oxidation occurred in one-electron transfer steps as indicated by the formation of ubisemiquinone. (2) Peroxynitrite promoted, in a concentration-dependent manner, the formation of superoxide anion by mitochondrial membranes. (3) Ubiquinol protected against peroxynitrite-mediated nitration of tyrosine residues in albumin and mitochondrial membranes, as suggested by experimental models, entailing either addition of ubiquinol or expansion of the mitochondrial ubiquinol pool caused by selective inhibitors of complexes III and IV. (4) Increase in membrane-bound ubiquinol partially prevented the loss of mitochondrial respiratory function induced by peroxynitrite. These findings are analysed in terms of the redox transitions of ubiquinone linked to both nitrogen-centred radical scavenging and oxygen-centred radical production. It may be concluded that the reaction of mitochondrial ubiquinol with peroxynitrite is part of a complex regulatory mechanism with implications for mitochondrial function and integrity.

scholarly journals Mucin inhibitsPseudomonas aeruginosabiofilm formation by significantly enhancing twitching motility

2014 ◽  
Vol 60 (3) ◽  
pp. 155-166 ◽  
Author(s):  
Cecily L. Haley ◽  
Cassandra Kruczek ◽  
Uzma Qaisar ◽  
Jane A. Colmer-Hamood ◽  
Abdul N. Hamood
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Type Iv Pili ◽  
Dependent Manner ◽  
Twitching Motility ◽  
Strain Pao1 ◽  
Concentration Dependent Manner ◽  
Dependent Effect ◽  
Type Iv ◽  
Biofilm Development

In Pseudomonas aeruginosa, type IV pili (TFP)-dependent twitching motility is required for development of surface-attached biofilm (SABF), yet excessive twitching motility is detrimental once SABF is established. In this study, we show that mucin significantly enhanced twitching motility and decreased SABF formation in strain PAO1 and other P. aeruginosa strains in a concentration-dependent manner. Mucin also disrupted partially established SABF. Our analyses revealed that mucin increased the amount of surface pilin and enhanced transcription of the pilin structural gene pilA. Mucin failed to enhance twitching motility in P. aeruginosa mutants defective in genes within the pilin biogenesis operons pilGHI/pilJK-chpA-E. Furthermore, mucin did not enhance twitching motility nor reduce biofilm development by chelating iron. We also examined the role of the virulence factor regulator Vfr in the effect of mucin. In the presence or absence of mucin, PAOΔvfr produced a significantly reduced SABF. However, mucin partially complemented the twitching motility defect of PAOΔvfr. These results suggest that mucin interferes with SABF formation at specific concentrations by enhancing TFP synthesis and twitching motility, that this effect, which is iron-independent, requires functional Vfr, and only part of the Vfr-dependent effect of mucin on SABF development occurs through twitching motility.

scholarly journals Antioxidant and Wound Healing Property of Gelsolin in 3T3-L1 Cells

2020 ◽  
Vol 2020 ◽  
pp. 1-7 ◽  
Author(s):  
Bhavna Vaid ◽  
Bhupinder Singh Chopra ◽  
Sachin Raut ◽  
Amin Sagar ◽  
Maulik D. Badmalia ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Wound Healing ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Plasma Gelsolin ◽  
Total Antioxidant ◽  
Effective Role ◽  
Healing Property ◽  
Injury Recovery

Delineation of factors which affect wound healing would be of immense value to enable on-time or early healing and reduce comorbidities associated with infections or biochemical stress like diabetes. Plasma gelsolin has been identified earlier to significantly enable injury recovery compared to placebo. This study evaluates the role of rhuGSN for its antioxidant and wound healing properties in murine fibroblasts (3T3-L1 cell line). Total antioxidant capacity of rhuGSN increased in a concentration-dependent manner (0.75-200 μg/mL). Cells pretreated with 0.375 and 0.75 μg/mL rhuGSN for 24 h exhibited a significant increase in viability in a MTT assay. Preincubation of cells with rhuGSN for 24 h followed by oxidative stress induced by exposure to H2O2 for 3 h showed cytoprotective effect. rhuGSN at 12.5 and 25 μg/mL concentration showed an enhanced cell migration after 20 h of injury in a scratch wound healing assay. The proinflammatory cytokine IL-6 levels were elevated in the culture supernatant. These results establish an effective role of rhuGSN against oxidative stress induced by H2O2 and in wound healing of 3T3-L1 fibroblast cells.

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