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Povzetek: This study investigated the antitumor efficacy of chemokine CCL5 gene therapy using gene electrotransfer (GET) in combination with radiotherapy (RT) in solid murine tumors CT26 and 4T1. In vitro, CT26 and 4T1 tumor cells transfected with plasmid DNA (pDNA) encoding CCL5 induced migration of RAW264.7 macrophages. In vivo, CCL5 overexpression achieved via GET of pDNA encoding CCL5 led to increased splenocyte infiltration in dorsal window chamber models. When combined with RT, GET of pDNA encoding CCL5 shifted the tumor cytokine profile toward a proinflammatory state, with elevated Ifn-γ, Cxcl9, Cxcl10, and Il-12α. Although CD8 + and CD4 + T cells were reduced post-treatment, due to radiation-induced cell death, the combination of GET of pDNA encoding CCL5 and RT significantly delayed tumor growth in both models. In 4T1 tumors, this delay was also significant compared to the equivalent treatment with GET of control pDNA. These findings support GET of pDNA encoding CCL5 combined with RT as a strategy to enhance immune-mediated tumor control.
Ključne besede: chemokines, gene electrotransfer, gene therapy, mouse, radiotherapy
Objavljeno v DiRROS: 13.02.2026; Ogledov: 430; Prenosov: 102
Celotno besedilo (12,90 MB)

Povzetek: Aim: Parvalbumin (PV) is a primary calcium buffer in mouse fast skeletal musclefibers. Previous work showed that PV ablation has a limited impact on cytosolicCa2+ ([Ca2+]cyto) transients and contractile response, while it enhances mitochon-drial density and mitochondrial matrix-free calcium concentration ([Ca2+]mito).Here, we aimed to quantitatively test the hypothesis that mitochondria act tocompensate for PV deficiency.Methods: We determined the free Ca 2+ redistribution during a 2 s 60 Hz tetanicstimulation in the sarcoplasmic reticulum, cytosol, and mitochondria. Via a re-action–diffusion Ca 2+ model, we quantitatively evaluated mitochondrial uptakeand storage capacity requirements to compensate for PV lack and analyzed pos-sible extracellular export.Results: [Ca 2+]mito during tetanic stimulation is greater in knock-out (KO)(1362 ± 392 nM) than in wild-type (WT) (855 ± 392 nM), p < 0.05. Under the as-sumption of a non-linear intramitochondrial buffering, the model predicts an ac-cumulation of 725 μmoles/Lfiber (buffering ratio 1:11 000) in KO, much higherthan in WT (137 μmoles/Lfiber, ratio 1:4500). The required transport rate via mi-tochondrial calcium uniporter (MCU) reaches 3 mM/s, compatible with availableliterature. TEM images of calcium entry units and Mn2+ quenching showed a greater capacity of store- operated calcium entry in KO compared to WT. However,levels of [Ca 2+]cyto during tetanic stimulation were not modulated to variations ofextracellular calcium.Conclusions: The model-based analysis of experimentally determined calciumdistribution during tetanic stimulation showed that mitochondria can act as abuffer to compensate for the lack of PV. This result contributes to a better under-standing of mitochondria's role in modulating [Ca2+]cyto in skeletal muscle fibers.
Ključne besede: calcium, mitochondria, mouse skeletal muscle fibers, parvalbumin, reaction-diffusion model
Objavljeno v DiRROS: 13.11.2024; Ogledov: 881; Prenosov: 3427
Celotno besedilo (3,97 MB)
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Povzetek: Cationic charge has been widely used to increase polymer adsorption and flocculation of dispersions or to provide antimicrobial activity. In this work, cationization of hydroxyethyl cellulose (HEC) and polyvinyl alcohol (PVA) was achieved by covalently coupling betaine hydrochloride and choline chloride to the polymer backbones through carbonyl diimidazole (CDI) activation. Two approaches for activation were investigated. CDI in excess was used to activate the polymers’ hydroxyls followed by carbonate formation with choline chloride, or CDI was used to activate betaine hydrochloride, followed by ester formation with the polymers’ hydroxyls. The first approach led to a more significant cross-linking of PVA, but not of HEC, and the second approach successfully formed ester bonds. Cationic, nitrogen-bearing materials with varying degrees of substitution were obtained in moderate to high yields. These materials were analyzed by Fourier transform infrared spectroscopy, nuclear magnetic resonance, polyelectrolyte titration, and kaolin flocculation. Their dose-dependent effect on the growth of Staphylococcus aureus and Pseudomonas aeruginosa, and L929 mouse fibroblasts, was investigated. Significant differences were found between the choline- and betaine-containing polymers, and especially, the choline carbonate esters of HEC strongly inhibited the growth of S. aureus in vitro but were also cytotoxic to fibroblasts. Fibroblast cytotoxicity was also observed for betaine esters of PVA but not for those of HEC. The materials could potentially be used as antimicrobial agents for instance by coating surfaces, but more investigations into the interaction between cells and polysaccharides are necessary to clarify why and how bacterial and human cells are inhibited or killed by these derivatives, especially those containing choline.
Ključne besede: hydroxyethyl cellulose, polyvinyl alcohol, antimicrobial, S. aureus, P. aeruginosa, L929 mouse fibroblast, cationic polymer
Objavljeno v DiRROS: 12.07.2024; Ogledov: 1322; Prenosov: 786
Celotno besedilo (3,21 MB)
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