Search bioRxiv⌕ Search
Home/Archive/bioRxiv

bioRxiv · 10.1101/2021.11.20.469396

Characterization of Reactive Oxygen Species Signaling changes in a cell culture model of skeletal muscle ageing, and its application to screening pharmacokinetically-relevant exposures of dietary polyphenols for bioactivity.

Hayes, N.·Fogarty, M.·Sadofsky, L.·Jones, H. S.
View original source ↗Export metadata ↓

Abstract

Age-related frailty is a significant health and social care burden, however treatment options are limited. There is currently a lack of suitable cell culture model for screening large numbers of test compounds to identifying those which can potentially promote healthy skeletal muscle function. This paper describes the characterization of reactive oxygen and nitrogen species (RONS) signalling changes in young and aged myoblasts and myotubes using the C2C12 cell line, and the application of aged myoblast and myotube cultures to assess the effect of dietary polyphenols on RONS signalling. Aged myoblasts and myotubes were observed to have significantly increased reactive oxygen species levels (p<0.01 and p<0.001 respectively), increases in nitric oxide levels (p<0.05 for myoblasts and myotubes), and lipid peroxidation markers (p<0.05 for myoblasts and myotubes). A panel of nine polyphenols were assessed in aged myoblasts and myotubes using concentrations and incubation times consistent with known pharmacokinetic parameters for these compounds. Of these, although several polyphenols were seen to reduce single markers of RONS signalling, only kaempferol and resveratrol consistently reduced multiple markers of RONS signalling with statistical significance in both cell models. Modulation of cellular enzymatic antioxidant activities (superoxide and catalase) was assessed as a possible mechanism of action for these polyphenols, and although both superoxide and catalase activities were significantly reduced in aged (versus young) myotubes (p<0.01 and p<0.05 respectively), no effect of polyphenol treatment on these enzyme activities were observed. Overall, this research has shown the utility of the C2C12 model, as both myoblasts and myotubes, as a suitable cell model for screening compounds for modulating RONS signalling in aged muscle, and that resveratrol and kaempferol (using pharmacokinetically-informed exposures) can modulate RONS signalling in skeletal muscle cells after an acute exposure.

Explore related subjects

pharmacology and toxicologyPreprint

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Hayes, N., Fogarty, M., Sadofsky, L., Jones, H. S.. 2021-11-22. Characterization of Reactive Oxygen Species Signaling changes in a cell culture model of skeletal muscle ageing, and its application to screening pharmacokinetically-relevant exposures of dietary polyphenols for bioactivity.. https://doi.org/10.1101/2021.11.20.469396

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

bioRxiv2026

Peptide Sequence Determines the Efficacy of Single-Dose AAV-Vectorized GLP-1R Agonists in Diet-Induced Obese Mice

Background: Glucagon-like peptide-1 receptor (GLP-1R) agonists such as semaglutide produce substantial weight loss and glycemic improvement, but their long-term efficacy depends on sustained adherence to chronic dosing. Adeno-associated virus (AAV) gene therapy could, in principle, provide durable GLP-1R agonist (GLP-1RA) exposure from a single administration, but the degree of peptide engineering required for a vectorized GLP-1RA transgene to be efficacious in vivo is unknown. Methods: We generated four self-complementary AAV (scAAV) constructs encoding: native human GLP-1(7-36) (GLP-1), a DPP-IV-resistant Gly8-GLP-1(7-36) variant (Gly8), Exendin-4 (Ex4), or an Exendin-4 human IgG4 Fc fusion protein (Ex4-Fc). All four constructs were validated to secrete functional GLP-1R agonists in vitro using a conditioned-media potency assay. Subsequently, these constructs were packaged into PHP.eB capsids and administered as a single intravenous dose (5x1012 vg/kg) to diet-induced obese (DIO) mice alongside a vehicle control. Body weight, body composition, food intake, fasting plasma insulin, and oral glucose tolerance were assessed over a 3-week period. At the end of the study, tissues were harvested for assessments of plasma/liver lipids, tissue transgene transcript and peptide levels. Results: HEK293 cells transfected with the four AAV constructs all secreted active peptides/proteins as assessed by a cell-based GLP-1R activation assay, although the effective concentration of the GLP-1 constructs in the media spanned nearly four orders of magnitude 72 hours after transfection. In diet-induced obese (DIO) mice, Ex4 and Ex4-Fc vectors, but not GLP-1 or Gly8 vectors, produced significant reductions in body weight of up to 22.6% of starting body weight out to 21 days after a single dose. In addition, reductions in food intake, fat mass, and fasting insulin relative to vehicle were also observed for Ex4 and Ex4-Fc. Furthermore, Ex4-Fc improved oral glucose tolerance while reducing plasma cholesterol and liver triglycerides relative to vehicle. Although transcript levels did not differ appreciably among the four constructs in either brain or liver, measurable peptide product in plasma and brain lysate tracked the rank order of the in vitro supernatant screen, with GLP-1 and Gly8 groups indistinguishable from endogenous background. Conclusions: PHP.eB scAAV Ex4 and Ex4-Fc showed robust efficacy on multiple metabolic endpoints including weight loss and glucose tolerance. In contrast, vectorized GLP-1 and Gly8 showed no in vivo efficacy despite comparable levels of viral transcript in the brain and the liver. Vectorized GLP-1 and Gly8 also performed poorly compared to exendin-4-based constructs in vitro, suggesting that conditioned-media potency screening is a valid early filter for construct selection in vectorized-peptide AAV development. Engineering peptides to improve translation and secretion efficiency, in addition to circulating plasma stability, could further optimize vectorized GLP-1RA therapeutics.

pharmacology and toxicology↗
bioRxiv2026

Preclinical Evaluation of a Novel BOC-Modified Triazoloacridinone (TRA-01AR) in Combination with 5-Fluorouracil in Colorectal Cancer

5-Fluorouracil (5-FU) remains a cornerstone of colorectal cancer (CRC) therapy, yet its clinical efficacy is limited by resistance, systemic toxicity, and unfavorable pharmacokinetics. Strategies that enhance tumor sensitivity while maintaining tolerability are therefore of considerable interest. Here, we evaluated 5-FU in combination with two triazoloacridinones, C-1305 and a novel BOC-modified derivative, TRA-01AR, using integrated cellular, transcriptomic, bioenergetic, and in vivo approaches. Both compounds induced cytotoxic effects across cancer cell models and produced overlapping but distinct transcriptional responses, primarily affecting DNA replication and cell cycle pathways. Bioenergetic profiling revealed a shift toward oxidative phosphorylation accompanied by reduced glycolysis, indicating modulation of cellular metabolism relevant to chemotherapy response. Interestingly, TRA-01AR exhibited delayed cytotoxicity relative to C-1305, although the underlying mechanism remains to be defined. In vivo, the combination of 5-FU with C-1305 significantly reduced tumor weight in HT-29 xenografts, whereas 5-FU combined with TRA-01AR did not result in a statistically significant reduction compared to 5-FU alone. TRA-01AR was associated with a more favorable systemic profile and increased intratumoral blood flow compared with C-1305. Collectively, these findings indicate that triazoloacridinones modulate transcriptional and metabolic programs relevant to the 5-FU response. While C-1305 demonstrated greater antitumor activity under the tested conditions, TRA-01AR exhibited distinct biological effects, including improved tolerability and vascular modulation. Further studies are required to clarify TRA-01AR's mechanism of action and assess its potential relevance in CRC-specific therapies.

pharmacology and toxicology↗
bioRxiv2026

Molecular Mechanisms of Quizartinib Resistance in FLT3 Mutants

Quizartinib, a type II FLT3 inhibitor approved for FLT3-ITD-positive acute myeloid leukemia (AML), is frequently limited by acquired resistance, which arises in up to 40% of patients with disease progression and is driven largely by the D835Y and F691L kinase-domain mutations. To define the underlying mechanisms, we performed triplicate 200-ns all-atom molecular dynamics simulations of wild-type FLT3, FLT3-D835Y, and FLT3-F691L in complex with Quizartinib, combining conformational analysis, MM-GBSA binding free-energy calculations, and binding-pocket characterization. Both mutations destabilized the inactive DFG-out conformation required for type II inhibitor binding, with mean binding free-energy reductions of 5 kcal/mol for D835Y and 10 kcal/mol for F691L relative to wild-type. D835Y disrupted the activation-loop electrostatic network and reduced Cys694 hydrogen-bond occupancy from 85% to 45%, whereas F691L abolished key van der Waals contacts and opened a 120 cubic Angstrom hydrophobic void at the gatekeeper position. Both mutants sampled a wider range of conformations and lost 14-17% of binding-pocket volume. These predictions were corroborated by CCK-8 viability assays and Western blotting of p-FLT3 (Y591) in Ba/F3 cells, which reproduced the predicted resistance hierarchy (F691L > D835Y > WT) at the cellular level. Together, these results indicate that D835Y and F691L confer resistance through distinct electrostatic and hydrophobic mechanisms that converge on destabilization of the inactive kinase conformation, providing a structural basis for the design of next-generation FLT3 inhibitors.

pharmacology and toxicology↗