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BackgroundDespite optimizations of coronary stenting technology, a residual risk of in-stent restenosis (ISR) remains. Vessel wall injury has important impact on the development of ISR. While injury can be assessed in histology, there is no injury score available to be used in clinical practice.MethodsSeven rats underwent abdominal aorta stent implantation. At 4 weeks after implantation, animals were euthanized, and strut indentation, defined as the impression of the strut into the vessel wall, as well as neointimal growth were assessed. Established histological injury scores were assessed to confirm associations between indentation and vessel wall injury. In addition, stent strut indentation was assessed by optical coherence tomography (OCT) in an exemplary clinical case.ResultsStent strut indentation was associated with vessel wall injury in histology. Furthermore, indentation was positively correlated with neointimal thickness, both in the per-strut analysis (r=0.5579) and in the per-section analysis (r=0.8620; both p ≤0.001). In a clinical case, indentation quantification in OCT was feasible, enabling assessment of injuryin vivo.ConclusionAssessing stent strut indentation enables periprocedural assessment of stent-induced damagein vivoand therefore allows for optimization of stent implantation. The assessment of stent strut indentation might become a valuable tool in clinical practice.

Extracellular collagen remodeling is one of the central mechanisms responsible for the structural and compositional coherence of myocardium in patients undergoing myocardial infarction (MI). Activated primary cardiac fibroblasts following myocardial infarction are extensively investigated to establish anti-fibrotic therapies to improve left ventricular remodeling. To systematically assess vitamin C functions as a potential modulator involved in collagen fibrillogenesis in an in vitro model mimicking heart tissue healing after MI. Mouse primary cardiac fibroblasts were isolated from wild-type C57BL/6 mice and cultured under normal and profibrotic (hypoxic + transforming growth factor beta 1) conditions on freshly prepared coatings mimicking extracellular matrix (ECM) remodeling during healing after an MI. At 10 μg/mL, vitamin C reprogramed the respiratory mitochondrial metabolism, which is effectively associated with a more increased accumulation of intracellular reactive oxygen species (iROS) than the number of those generated by mitochondrial reactive oxygen species (mROS). The mRNA/protein expression of subtypes I, III collagen, and fibroblasts differentiations markers were upregulated over time, particularly in the presence of vitamin C. The collagen substrate potentiated the modulator role of vitamin C in reinforcing the structure of types I and III collagen synthesis by reducing collagen V expression in a timely manner, which is important in the initiation of fibrillogenesis. Altogether, our study evidenced the synergistic function of vitamin C at an optimum dose on maintaining the equilibrium functionality of radical scavenger and gene transcription, which are important in the initial phases after healing after an MI, while modulating the synthesis of de novo collagen fibrils, which is important in the final stage of tissue healing.

International journal of molecular sciences 23(21), 12842 (2022). doi:10.3390/ijms232112842 special issue: "Special Issue "Novel Biological Molecules for Cancer Treatments" / Special Issue Editor: Lina Sabatino, Guest Editor", Published by Molecular Diversity Preservation International, Basel

International journal of molecular sciences 23(20), 12612 (2022). doi:10.3390/ijms232012612 special issue: "Special Issue "Molecular Study of Cardiac Death" / Special Issue Editor: Sorin Hostiuc, Guest Editor", Published by Molecular Diversity Preservation International, Basel

Skeletal muscles harbour a resident population of stem cells, termed satellite cells (SCs). After trauma, SCs leave their quiescent state to enter the cell cycle and undergo multiple rounds of proliferation, a process regulated by MyoD. To initiate differentiation, fusion and maturation to new skeletal muscle fibres, SCs up-regulate myogenin. However, the regulation of these myogenic factors is not fully understood. In this study we demonstrate that Nrf2, a major regulator of oxidative stress defence, plays a role in the expression of these myogenic factors. In both promoter studies with myoblasts and a mouse model of muscle injury in Nrf2-deficient mice, we show that Nrf2 prolongs SC proliferation by up-regulating MyoD and suppresses SC differentiation by down-regulating myogenin. Moreover, we show that IL-6 and HGF, both factors that facilitate SC activation, induce Nrf2 activity in myoblasts. Thus, Nrf2 activity promotes muscle regeneration by modulating SC proliferation and differentiation and thereby provides implications for tissue regeneration.