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Several adenosine A receptor (AR) radiotracers for positron emission tomography (PET) have been developed to study their neuromodulatory functions and role in brain disorders. While two xanthine-based radiotracers ([C]-MPDX and [F]-CPFPX) have been used in humans, we aimed to improve the metabolic stability and specific binding. Guided by structure-activity relationship (SAR) studies, 10 derivatives were synthesized with binding affinities up to 0.12 nM. Three subnanomolar candidates (, , ) were radiolabeled with C-11 ( = 20.4 min) for evaluation using in vivo PET imaging and ex vivo rodent brain biodistribution. Although [C] demonstrated a higher blood-brain barrier (BBB) permeability, negligible in vivo specific binding was observed. Ex vivo studies indicated that all three compounds are substrates for brain efflux pumps. Despite optimized affinity, BBB permeability and in vivo binding specificity remain challenges. These findings inform development of nonxanthine AR radiotracers and highly potent CNS AR drugs.
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http://dx.doi.org/10.1021/acsmedchemlett.5c00249 | DOI Listing |
Pharm Res
September 2025
Mechanical and Aerospace Engineering Department, University of Texas at Arlington, 500 W First St, Rm 211, Arlington, TX, 76019, USA.
Objective: A fundamental understanding of drug diffusion and binding processes is critical for the design and optimization of a wide variety of drug delivery devices. Most of the past literature assume binding to occur uniformly throughout the tissue, or, at best, in specific layers of a multilayer tissue. However, in many realistic scenarios, such as in cancer-targeting drugs, drug binding occurs in discrete irregularly shaped regions.
View Article and Find Full Text PDFCancer Immunol Immunother
September 2025
Department of Thoracic Surgery, Tangdu Hospital, Fourth Military Medical University, Xi'an, 710038, China.
Objective: CircRNAs are involved in cancer progression. However, their role in immune escape in non-small cell lung cancer (NSCLC) remains poorly understood.
Methods: This study employed RIP-seq for the targeted enrichment of circRNAs, followed by Western blotting and RT-qPCR to confirm their expression.
Nat Aging
September 2025
State Key Laboratory of Conservation and Utilization of Bio-resources in Yunnan and Center for Life Sciences, School of Life Sciences, Yunnan University, Kunming, China.
Membraneless organelles assembled by liquid-liquid phase separation interact with diverse membranous organelles to regulate distinct cellular processes. It remains unknown how membraneless organelles are engaged in mitochondrial homeostasis. Here we demonstrate that mitochondria-associated translation organelles (MATOs) mediate local synthesis of proteins required for structural and functional maintenance of mitochondria.
View Article and Find Full Text PDFNat Commun
September 2025
Department of Biochemistry, University of Illinois, Urbana-Champaign, IL, USA.
Individuals with progressive liver failure risk dying without liver transplantation. However, our understanding of why regenerative responses are disrupted in failing livers is limited. Here, we perform multiomic profiling of healthy and diseased human livers using bulk and single-nucleus RNA- and ATAC-seq.
View Article and Find Full Text PDFRev Med Interne
September 2025
Service d'hématologie biologique, CHU d'Amiens-Picardie, Amiens, France; HEMATIM UR4666, université Picardie Jules-Verne, Amiens, France.
The diagnosis of hemolysis is still based on straightforward biochemical parameters: haptoglobin (the most sensitive), lactate dehydrogenase (LDH), and unconjugated bilirubin. Anemia is not always present. Reticulocyte counts typically exceed 120×10/L, except in cases of associated vitamin deficiency or during the very early phase of acute hemolysis.
View Article and Find Full Text PDF