✍🏼 Chetan Ahire, Adam Nyul-Toth, Jordan DelFavero, Rafal Gulej, Janet A. Faakye, Stefano Tarantini, Tamas Kiss, Anna Kuan-Celarier, Priya Balasubramanian, Anna Ungvari, Amber Tarantini, Raghavendra Nagaraja, Feng Yan, Qinggong Tang, Peter Mukli, Tamas Csipo, Andriy Yabluchanskiy, Judith Campisi, Zoltan Ungvari, Anna Csiszar

🏠 University of Oklahoma Health Sciences Center, Oklahoma City, OK

📑 Aging Cell (2023)

Abstract
Chemotherapy-induced cognitive impairment (“chemobrain”) is a frequent side-effect in cancer survivors treated with paclitaxel (PTX). The mechanisms responsible for PTX-induced cognitive impairment remain obscure, and there are no effective treatments or prevention strategies. Here, we test the hypothesis that PTX induces endothelial senescence, which impairs microvascular function and contributes to the genesis of cognitive decline. We treated transgenic p16-3MR mice, which allows the detection and selective elimination of senescent cells, with PTX (5 mg/kg/day, 2 cycles; 5 days/cycle). PTX-treated and control mice were tested for spatial memory performance, neurovascular coupling (NVC) responses (whisker-stimulation-induced increases in cerebral blood flow), microvascular density, blood–brain barrier (BBB) permeability and the presence of senescent endothelial cells (by flow cytometry and single-cell transcriptomics) at 6 months post-treatment. PTX induced senescence in endothelial cells, which associated with microvascular rarefaction, NVC dysfunction, BBB disruption, neuroinflammation, and impaired performance on cognitive tasks. To establish a causal relationship between PTX-induced senescence and impaired microvascular functions, senescent cells were depleted from PTX-treated animals (at 3 months post-treatment) by genetic (ganciclovir) or pharmacological (treatment with the senolytic drug ABT263/Navitoclax) means. In PTX treated mice, both treatments effectively eliminated senescent endothelial cells, rescued endothelium-mediated NVC responses and BBB integrity, increased capillarization and improved cognitive performance. Our findings suggest that senolytic treatments can be a promising strategy for preventing chemotherapy-induced cognitive impairment.

How the WOLF was used in this study
The authors utilized the WOLF Cell Sorter to enrich and isolate endothelial cells exhibiting markers of senescence from mouse brain tissue for downstream analysis. After preparing single-cell suspensions from the brains of treated and control mice, they identified cells based on surface markers (including endothelial markers) and senescence-associated fluorescent reporters. This sorting step enabled the researchers to obtain highly purified populations of viable senescent and non-senescent endothelial cells, which were essential for accurately assessing senescence burden and for subsequent molecular and functional assays that linked endothelial senescence with blood–brain barrier dysfunction and cognitive decline in the chemobrain model.