Some nucleoside analogues currently used as antiretroviral agents might promote mutagenesis besides their putative ability to interfere with endogenous nucleotide metabolism and/or inhibit viral transcription. The intracellular concentration of nucleosides and nucleobases is to some extent the result of the metabolic background of the specific cell line used for infection studies, its particular suit of enzymes and transporters. This review focuses on the transporter-mediated pathways implicated in either the uptake or the efflux of nucleoside- and nucleobase-derivatives. From a biochemical point of view, four different types of transport processes for nucleoside-related antiviral drugs have been described: (1) equilibrative uniport, (2) substrate exchange, (3) concentrative Na+- or H+-dependent uptake and finally, (4) substrate export through primary ATP-dependent active efflux pumps. These mechanisms are mainly related to the following set of transporter families: Concentrative Nucleoside Transporter (CNT), Equilibrative Nucleoside Transporter (ENT), Organic Anion Transporter (OAT) and Organic Cation Transporter (OCT), Peptide Transporter (PEPT) and Multidrug Resistance Protein (MRP). The basic properties of these carrier proteins and their respective role in the transport across the plasma membrane of nucleoside-derived antiviral drugs are reviewed.
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http://dx.doi.org/10.1016/j.virusres.2004.11.005 | DOI Listing |
Proc Natl Acad Sci U S A
January 2025
Department of Chemistry, University of California, Berkeley, CA 94720.
Copper is an essential nutrient for sustaining vital cellular processes spanning respiration, metabolism, and proliferation. However, loss of copper homeostasis, particularly misregulation of loosely bound copper ions which are defined as the labile copper pool, occurs in major diseases such as cancer, where tumor growth and metastasis have a heightened requirement for this metal. To help decipher the role of copper in the etiology of cancer, we report a histochemical activity-based sensing approach that enables systematic, high-throughput profiling of labile copper status across many cell lines in parallel.
View Article and Find Full Text PDFACS Chem Biol
January 2025
Department of Chemistry, Binghamton University, the State University of New York, Binghamton, New York 13902, United States.
RNA interference (RNAi) has rapidly matured as a novel therapeutic approach. In this field, chemical modifications have been critical to the clinical success of short interfering RNAs (siRNAs). Notwithstanding the significant advances, achieving robust durability and gene silencing in extrahepatic tissues, as well as reducing off-target effects of siRNA, are areas where chemical modifications can still improve siRNA performance.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Department of Chemistry, University of California, Riverside, California 92521-0403, United States.
Pseudouridine (Ψ) is the most abundant RNA modification in nature; however, not much is known about the biological functions of this modified nucleoside. Employing an unbiased quantitative proteomics method, we identified multiple candidate reader proteins of Ψ in RNA, including a cytoskeletal protein profilin-1 (PFN1). We demonstrated that PFN1 binds directly and selectively to Ψ-containing RNA.
View Article and Find Full Text PDFWorld J Gastroenterol
January 2025
Department of Gastroenterology and Liver Services, Concord Repatriation General Hospital, Sydney 2139, New South Wales, Australia.
Background: Ulcerative colitis (UC) is a chronic inflammatory condition requiring continuous treatment and monitoring. There is limited pharmacokinetic data on vedolizumab during maintenance therapy and the effect of thiopurines on vedolizumab trough concentrations is unknown.
Aim: To investigate the exposure-response relationship of vedolizumab and the impact of thiopurine withdrawal in UC patients who have achieved sustained clinical and endoscopic remission during maintenance therapy.
Sci Rep
January 2025
Department of Pathology, The Second Xiangya Hospital of Central South University, Changsha, China.
MicroRNA (miRNA) dysregulation has been identified in several carcinomas, including non-small cell lung cancer (NSCLC), and is known to play a role in the development and progression of this disease. We initially conducted a miRNA microarray analysis, which revealed that the MNK inhibitor CGP57380 increased the expression of miR-150-3p. A similar analysis was performed using data from The Cancer Genome Atlas (TCGA).
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