Biology subjects

Dudley, S.

Publications and source records attributed to Dudley, S..

3 recordsLinked to original sources

bioRxiv2025

Enhancement of Therapeutic Transgene Insertion for Murine Phenylketonuria

Low in vivo transgene integration frequency limits the therapeutic efficacy of homology-directed repair (HDR)-mediated gene insertion as a treatment for Mendelian disorders. This study demonstrates improved efficacy of HDR-mediated gene insertion for the treatment of murine phenylalanine hydroxylase (PAH) deficiency, a model of human phenylketonuria (PKU), through pharmacologic inhibition of competing DNA repair pathways. Targeted integration of a Pah-expressing transgene into the hepatocytes of neonatal mice was enhanced with vanillin, a potent inhibitor of non-homologous end joining (NHEJ). This was further improved following combination of vanillin and novobiocin, an inhibitor of microhomology-mediated end joining (MMEJ). Combined NHEJ and MMEJ inhibition yielded PAH-expressing transgene insertions in approximately 10% of targeted alleles and was associated with a 70.6% decrease in serum phenylalanine. Demonstrating that pharmacologic inhibition of DNA repair pathways that compete with HDR can significantly enhance HDR-mediated transgene insertion in vivo.

genomics↗

bioRxiv2024

Macrophage-derived CCL24 promotes fibrosis and worsens cardiac dysfunction during heart failure

Inflammation is a significant risk factor and contributes to cardiovascular disease by driving both adaptive and maladaptive processes. Macrophages are the most abundant immune cells in the heart and play an important role in the remodeling of cardiac tissue. We have previously shown an overall protective function of resident cardiac macrophages after pressure-overloaded injury. However, a subpopulation of resident macrophages also expresses high levels of the profibrotic CC motif chemokine ligand 24 (CCL24), suggesting a dichotomous role in pressure overload-induced cardiac remodeling. Here, we report that following transverse aortic constriction CCL24 knockout (CCL24 KO) mice have improved systolic function, cardiac wall enlargement, as well as increased myocyte surface area and hypertrophy, suggesting that CCL24 disrupts compensatory hypertrophy. TAC-operated CCL24 KO mice also displayed reduced fibrosis and diminished expression of fibrotic genes, implying a pro-fibrotic role for CCL24. Indeed, CCL24 induced the proliferation and activation of primary mouse fibroblasts in a process that required CCR3, the sole G protein-coupled receptor for CCL24. Correspondingly, selective ablation of CCR3 in fibroblasts improved cardiac function and ameliorated fibrosis following pressure overload. Administration of a CCL24 blocking antibody or a CCR3 antagonist both improved cardiac function in pressure-overloaded mice, highlighting the CCL24-CCR3 axis as a potential therapeutic target for heart failure. Finally, CCL24 deficiency improved cardiac function and ameliorated fibrosis during physiological aging. Overall, these results show that macrophage-derived CCL24 aggravates fibrosis via the CCR3 receptor, leading to impaired cardiac function in acute and chronic heart failure.

immunology↗

bioRxiv2021

Slow-oscillatory tACS does not modulate human motor cortical response to repeated plasticity paradigms

Previous history of activity and learning modulates synaptic plasticity and can lead to saturation of synaptic connections. According to the synaptic homeostasis hypothesis, neural oscillations during slow-wave sleep play an important role in restoring plasticity within a functional range. However, it is not known whether slow-wave oscillations - without the concomitant requirement of sleep - play a causal role in human synaptic homeostasis. Here, slow-oscillatory transcranial alternating current stimulation (tACS, 1Hz, 1mA, 18 minutes) was interleaved between two plasticity-inducing interventions: motor learning, and a paradigm known to induce long-term-potentiation-like plasticity in human motor cortex (paired associative stimulation; PAS). The hypothesis tested was that slow-oscillatory tACS would abolish the expected interference between motor learning and PAS, and facilitate plasticity from successive interventions. Thirty-six participants received sham and active fronto-motor tACS in two separate sessions, along with electroencephalography (EEG) recordings. A further 38 participants received tACS through a control (posterior midline) montage. Using neuro-navigated transcranial magnetic stimulation (TMS) over the left motor cortex, motor evoked potentials (MEPs) were recorded throughout the session. Bayesian statistics were used to quantify evidence for or against the hypothesis of an effect of each intervention on MEP amplitude. As expected, there was converging evidence that motor training increased MEPs. Importantly, we found moderate evidence against an effect of active tACS in restoring PAS plasticity, and no evidence of lasting entrainment of slow-oscillations in the EEG. This suggests that, under the conditions tested here, slow-oscillatory tACS does not modulate synaptic homeostasis in the motor system of awake humans.

neuroscience↗