Purpose: The objective of this research was to investigate the presence of sodium-dependent multivitamin transporter (SMVT) on rabbit corneal epithelial cells.
Methods: Primary cultured rabbit corneal epithelial cells (rPCECs)and freshly excised rabbit corneas were used for characterization of biotin uptake and transport, respectively. Reverse transcription-polymerase chain reaction (RT-PCR) was performed to confirm the molecular identity of SMVT. Liquid chromatography/tandem mass spectrometry (LC-MS/MS) analysis was performed to examine the presence of biotin in rabbit tears.
Results: Uptake of biotin by rPCECs was found to be time and concentration dependent with Km of 32.52 microM and Vmax of 10.43 pmol min- 1 mg protein- 1. Biotin was significantly inhibited in the presence of pantothenic acid and lipoic acid. Biotin uptake was found to be energy and Na+ dependent but H+ and Cl- independent. The uptake was inhibited by valeric acid in a concentration-dependent manner but not much affected in the presence of biotin methyl ester and biocytin with no free carboxyl group. Modulators of both PKC- and PKA-mediated pathways had no effect on biotin uptake, but calcium-calmodulin inhibitor significantly inhibited its uptake. Sodium-dependent multivitamin transporter was identified by RT-PCR in rPCECs. Transport experiments across the rabbit corneas revealed the functional localization of SMVT on the apical side of the cornea, and thereby corroborating with in vitro results with cultured corneal cells. Finally, LC-MS/MS analysis showed the presence of biotin in rabbit tears.
Conclusions: Results obtained from both in vitro and exvivo studies suggest the possible role of SMVT expressed on corneal epithelial cells for the uptake of biotin, which co-transports pantothenic acid and lipoic acid. Further, the presence of biotin in tears suggests the physiological significance of this transporter in rabbit corneal epithelium.
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http://dx.doi.org/10.1080/02713680600900206 | DOI Listing |
Biomolecules
January 2025
Department of Entomology, University of Arizona, Tucson, AZ 85721, USA.
Pantothenate (Pan), or vitamin B5, is essential for the synthesis of co-enzyme A (CoA), acetyl-CoA, and numerous downstream physiological processes. We previously demonstrated that Pan is not only essential for mosquito survival, but also for the development of malaria parasites within the mosquito, suggesting that targeting Pan and CoA biosynthesis may be a novel approach for malaria control. However, little is known about how Pan is acquired and mobilized within the mosquito.
View Article and Find Full Text PDFCarbohydr Polym
March 2025
Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montreal, QC H3A 0B8, Canada; Quebec Centre for Advanced Materials (QCAM) and Pulp and Paper Research Centre, McGill University, 3420 University Street, Montreal, QC H3A 2A7, Canada. Electronic address:
The synergy between nanomaterials as solid supports and supramolecular concepts has resulted in nanomaterials with hierarchical structure and enhanced functionality. Herein, we developed and investigated innovative supramolecular functionalities arising from the synergy between organic moieties and the preexisting nanoscale soft material backbones. Based on these complex molecular nano-architectures, a new nanorod carbohydrate polymer carrier was designed with bifunctional hairy nanocellulose (BHNC) to reveal dual-responsive advanced drug delivery (ADD).
View Article and Find Full Text PDFmBio
January 2025
Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada.
Many bacterial toxins exert their cytotoxic effects by enzymatically inactivating one or more cytosolic targets in host cells. To reach their intracellular targets, these toxins possess functional domains or subdomains that interact with and exploit various host factors and biological processes. Despite great progress in identifying many of the key host factors involved in the uptake of toxins, significant knowledge gaps remain as to how partially characterized and newly discovered microbial toxins exploit host factors or processes to intoxicate target cells.
View Article and Find Full Text PDFACS Omega
December 2024
School of Life Science and Technology, Institute of Science Tokyo, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8501, Japan.
A critical challenge in boron neutron capture therapy (BNCT) is expanding its effectiveness through the development of novel boron agents with different mechanisms of action than the approved drug 4-borono-l-phenylalanine (BPA). In this study, we developed a small molecule boron carrier, biotinyl--dodecaborate conjugate with an iodophenyl moiety (BBC-IP), incorporating biotin as a ligand for biotin receptors overexpressed in various cancer cells, alongside an albumin ligand and boron source. BBC-IP exhibited high water solubility, minimal cytotoxicity, and superior cellular uptake compared to BPA in both human and mouse cancer cells.
View Article and Find Full Text PDFJ Control Release
December 2024
The State Key Laboratory of Pharmaceutical Biotechnology and Department of Neurology of Nanjing Drum Tower Hospital, School of Life Sciences and The Affiliated Hospital of Nanjing University Medical School, Nanjing University, Nanjing 210023, China; Changzhou High-Tech Research Institute of Nanjing University and Jiangsu TargetPharma Laboratories Inc, Changzhou 213164, China.
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