Modulation of a Cellular Transport Activity by Capsicum Extracts

2018 ◽  
Vol 14 (2) ◽  
pp. 149-152
Author(s):  
Jie Chen ◽  
Vai H. Fong ◽  
Amandio Vieira
Keyword(s):  
Cellular Transport ◽  
Transport Activity

Assessment of extracellular glucose distribution and glucose transport activity in conscious rats

1995 ◽  
Vol 268 (4) ◽  
pp. E712-E721 ◽  
Author(s):  
J. H. Youn ◽  
J. K. Kim ◽  
G. M. Steil
Keyword(s):  
Glucose Transport ◽  
Insulin Infusion ◽  
Compartmental Analysis ◽  
Time Profile ◽  
Cellular Transport ◽  
Transport Activity ◽  
Conscious Rats ◽  
Distribution Kinetics ◽  
Extracellular Glucose

The effects of insulin on extracellular glucose distribution and cellular glucose transport activity were studied by simultaneously analyzing the plasma kinetics of L-[1-14C]glucose and 3-O-[3H]methylglucose after an intravenous injection during saline or insulin infusion (euglycemic glucose clamp) in conscious rats (n = 7 for each). The time profiles of plasma L-glucose were almost superimposable in the two protocols, and compartmental analysis showed that neither distribution volumes nor distribution rate constants were affected with insulin (P > 0.05 for all), suggesting that glucose distribution within the extracellular space was not influenced with insulin. In contrast, the time profile of plasma 3-O-methylglucose (3-MG) was markedly altered with insulin; the initial decrease was much faster during insulin infusion than during saline infusion, indicating stimulation of 3-MG transport into intracellular spaces with insulin. The 3-MG data were analyzed using a comprehensive model separately describing extracellular distribution and cellular transport of 3-MG by incorporating information on extracellular distribution kinetics obtained from L-glucose data. The combined L-glucose and 3-MG kinetic analysis precisely estimated insulin's effect in vivo to stimulate glucose transport into and out of intracellular spaces. We conclude that 1) insulin does not affect extracellular glucose distribution kinetics or volumes in conscious rats and 2) insulin's effects on cellular glucose transport in vivo can be assessed by simultaneous analysis of plasma L-glucose and 3-MG kinetics.

Glucose as regulator of glucose transport activity and glucose-transporter mRNA in hamster beta-cell line

Diabetes ◽  
1992 ◽  
Vol 41 (5) ◽  
pp. 592-597 ◽  
Author(s):  
N. Inagaki ◽  
K. Yasuda ◽  
G. Inoue ◽  
Y. Okamoto ◽  
H. Yano ◽  
...  
Keyword(s):  
Beta Cell ◽  
Cell Line ◽  
Glucose Transport ◽  
Glucose Transporter ◽  
Transport Activity ◽  
Beta Cell Line ◽  
Glucose Transporter Mrna

scholarly journals B0AT1 amino acid transporter complexed with SARS-CoV-2 receptor ACE2 forms a heterodimer functional unit: in situ conformation using radiation inactivation analysis

Function ◽  
2021 ◽  
Author(s):  
Bruce R Stevens ◽  
J Clive Ellory ◽  
Robert L Preston
Keyword(s):  
Amino Acid ◽  
Membrane Trafficking ◽  
Functional Unit ◽  
Membrane Vesicles ◽  
High Energy ◽  
Amino Acid Transporter ◽  
Neutral Amino Acid ◽  
Transport Activity ◽  
Acid Transporter

Abstract The SARS-CoV-2 receptor, Angiotensin Converting Enzyme-2 (ACE2), is expressed at levels of greatest magnitude in the small intestine as compared to all other human tissues. Enterocyte ACE2 is co-expressed as the apical membrane trafficking partner obligatory for expression and activity of the B0AT1 sodium-dependent neutral amino acid transporter. These components are assembled as an [ACE2: B0AT1]2 dimer-of-heterodimers quaternary complex that putatively steers SARS-CoV-2 tropism in the gastrointestinal (GI) tract. GI clinical symptomology is reported in about half of COVID-19 patients, and can be accompanied by gut shedding of virion particles. We hypothesized that within this 4-mer structural complex, each [ACE2: B0AT1] heterodimer pair constitutes a physiological “functional unit.” This was confirmed experimentally by employing purified lyophilized enterocyte brush border membrane vesicles that were exposed to increasing doses of high-energy electron radiation from a 16 MeV linear accelerator. Based on established target theory, the results indicated the presence of Na+-dependent neutral amino acid influx transport activity functional unit with target size mw = 183.7 ± 16.8 kDa in situ in intact apical membranes. Each thermodynamically stabilized [ACE2: B0AT1] heterodimer functional unit manifests the transport activity within the whole ∼345 kDa [ACE2: B0AT1]2 dimer-of-heterodimers quaternary structural complex. The results are consistent with our prior molecular docking modeling and gut-lung axis approaches to understanding COVID-19. These findings advance the understanding of the physiology of B0AT1 interaction with ACE2 in the gut, and thereby potentially contribute to translational developments designed to treat or mitigate COVID-19 variant outbreaks and/or GI symptom persistence in long-haul Post-Acute Sequelae of SARS-CoV-2 (PASC).

scholarly journals L1210/B23.1 cells express equilibrative, inhibitor-sensitive nucleoside transport activity and lack two parental nucleoside transport activities.

1992 ◽  
Vol 267 (24) ◽  
pp. 16951-16956
Author(s):  
D Vijayalakshmi ◽  
L Dagnino ◽  
J.A. Belt ◽  
W.P. Gati ◽  
C.E. Cass ◽  
...  
Keyword(s):  
Nucleoside Transport ◽  
Transport Activity

scholarly journals A Novel Curcumin-Mycophenolic Acid Conjugate Inhibited Hyperproliferation of Tumor Necrosis Factor-Alpha-Induced Human Keratinocyte Cells

Pharmaceutics ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 956
Author(s):  
Yonelian Yuyun ◽  
Pahweenvaj Ratnatilaka Na Bhuket ◽  
Wiwat Supasena ◽  
Piyapan Suwattananuruk ◽  
Kemika Praengam ◽  
...  
Keyword(s):  
Tumor Necrosis Factor ◽  
Tumor Necrosis Factor Alpha ◽  
Mycophenolic Acid ◽  
Tumor Necrosis ◽  
Molecular Mechanisms ◽  
Cellular Transport ◽  
Necrosis Factor Alpha ◽  
Factor Alpha ◽  
Anti Inflammatory ◽  
Necrosis Factor

Curcumin (CUR) has been used as adjuvant therapy for therapeutic application in the treatment of psoriasis through several mechanisms of action. Due to the poor oral bioavailability of CUR, several approaches have been developed to overcome the limitations of CUR, including the prodrug strategy. In this study, CUR was esterified with mycophenolic acid (MPA) as a novel conjugate prodrug. The MPA-CUR conjugate was structurally elucidated using FT-IR, 1H-NMR, 13C-NMR, and MS techniques. Bioavailable fractions (BFs) across Caco-2 cells of CUR, MPA, and MPA-CUR were collected for further biological activity evaluation representing an in vitro cellular transport model for oral administration. The antipsoriatic effect of the BFs was determined using antiproliferation and anti-inflammation assays against hyperproliferation of tumor necrosis factor-alpha (TNF-α)-induced human keratinocytes (HaCaT). The BF of MPA-CUR provided better antiproliferation than that of CUR (p < 0.001). The enhanced hyperproliferation suppression of the BF of MPA-CUR resulted from the reduction of several inflammatory cytokines, including IL-6, IL-8, and IL-1β. The molecular mechanisms of anti-inflammatory activity were mediated by an attenuated signaling cascade of MAPKs protein, i.e., p38, ERK, and JNK. Our results present evidence for the MPA-CUR conjugate as a promising therapeutic agent for treating psoriasis by antiproliferative and anti-inflammatory actions.

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