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Background: A neuropathogenic hallmark of Alzheimer's disease (AD) is loss of neuronal synapses in selective brain regions. Small GTPases Rac1 and Cdc42, critical modulators of synaptic architecture and remodeling, are dysregulated in AD brains and are potential AD therapeutic targets. However, the exact contribution of their signaling to AD is still not clear.
Objective: We intend to investigate the hypothesis that Rac1/Cdc42 activity changes in a spatial and planar dependent manner in relation to AD.
Methods: We applied anti-pRac/Cdc42 (Serine 71 phosphorylation), which recognizes an inactive form of Rac1/Cdc42, and anti-pPAK (Threonine 423 phosphorylation), which detects the active PAK, a positive downstream effector of Rac1/Cdc42 signaling. For this study, triple transgenic mouse model (3xTg-AD) brain and human AD brain samples were used.
Results: pRac/Cdc42 expression was decreased in 3xTg-AD mouse cortex while pPAK expression increased compared to wild-type mouse cortex. Immunostaining of mouse brain serial sections revealed increased pRac/Cdc42 expression in the rostral region, decreased expression in the caudal region, and pPAK showed an overall opposite trend of pRac/Cdc42. There was also a brain plane specific nuclear to cytoplasmic redistribution of pRac/Cdc42. Human non-dementia and AD cortex and cerebellum showed differential expressions for pRac/Cdc42, Rac1, and Cdc42. Mouse whole transcriptome analysis demonstrated spatial dependent expression of Rac1/Cdc42 signaling-associated genes in neuronal and non-neuronal (astrocyte) populations of 3xTg-AD hippocampi.
Conclusions: Rac1/Cdc42 signaling is dysregulated in both 3xTg-AD mouse and AD human brain and Rac1/Cdc42 activity level changes along the spatial and planar dimensions.
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http://dx.doi.org/10.1177/13872877241291076 | DOI Listing |
Light Sci Appl
September 2025
National Laboratory of Solid State Microstructures, Key Laboratory of Intelligent Optical Sensing and Manipulation, College of Engineering and Applied Sciences, Nanjing University, 210023, Nanjing, China.
Planar optical elements incorporating space-varying Pancharatnam-Berry phase have revolutionized the manipulation of light fields by enabling continuous control over amplitude, phase, and polarization. While previous research focusing on linear functionalities using apolar liquid crystals (LCs) has attracted much attention, extending this concept to the nonlinear regime offers unprecedented opportunities for advanced optical processing. Here, we demonstrate the reconfigurable nonlinear Pancharatnam-Berry LC diffractive optics in photopatterned ion-doped ferroelectric nematics.
View Article and Find Full Text PDFJ Synchrotron Radiat
November 2025
Advanced Photon Source, Argonne National Laboratory, Lemont, IL 60439, USA.
Nano-laminography combines the penetrating power of hard X-rays with a tilted rotational geometry to deliver high-resolution, three-dimensional images of laterally extended, flat specimens that are otherwise incompatible with, or difficult to image using, conventional nano-tomography. In this work, we demonstrate a full-field, X-ray nano-laminography system implemented with the transmission X-ray microscope at beamline 32-ID of the upgraded Advanced Photon Source at Argonne National Laboratory, USA. By rotating the sample around an axis inclined by 20° to the incident beam, the technique minimizes the long optical path lengths that would otherwise generate excessive artifacts when planar samples are imaged edge-on.
View Article and Find Full Text PDFJ Magn Reson Imaging
September 2025
School of Biomedical Engineering, Guangdong Provincial Key Laboratory of Medical Image Processing and Guangdong Province Engineering Laboratory for Medical Imaging and Diagnostic Technology, Southern Medical University, Guangzhou, China.
Background: The dynamic progression of gray matter (GM) microstructural alterations following radiotherapy (RT) in patients, and the relationship between these microstructural abnormalities and cortical morphometric changes remains unclear.
Purpose: To longitudinally characterize RT-related GM microstructural changes and assess their potential causal links with classic morphometric alterations in patients with nasopharyngeal carcinoma (NPC).
Study Type: Prospective, longitudinal.
ACS Nano
September 2025
State Key Laboratory of Chemo and Biosensing, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China.
Optical imaging offers high sensitivity and specificity for noninvasive cancer detection, but conventional techniques suffer from limited probe accumulation, tissue autofluorescence, and poor depth resolution. Afterglow luminescence overcomes autofluorescence by emitting persistent light after excitation, yet its utility in vivo remains hindered by weak tumor enrichment and two-dimensional readouts lacking spatial context. Here, we report luminescent-magnetic nanoparticles (LM-NPs) coencapsulating luminescent trianthracene (TA) molecules and iron oxide cores within the amphiphilic polymer pluronic-F127.
View Article and Find Full Text PDFBMC Ecol Evol
September 2025
Lehrstuhl für Zoologie, TUM School of Life Sciences, Technical University of Munich, Liesel-Beckmann Strasse 4, Freising, 85354, Germany.
Accurate three-dimensional localisation of ultrasonic bat calls is essential for advancing behavioural and ecological research. I present a comprehensive, open-source simulation framework-Array WAH-for designing, evaluating, and optimising microphone arrays tailored to bioacoustic tracking. The tool incorporates biologically realistic signal generation, frequency-dependent propagation, and advanced Time Difference of Arrival (TDoA) localisation algorithms, enabling precise quantification of both positional and angular accuracy.
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