This study describes the effect of collagen type I (Col I) oxidation on its physiological remodeling by adipose tissue-derived mesenchymal stem cells (ADMSCs), both mechanical and proteolytic, as an in vitro model for the acute oxidative stress that may occur in vivo upon distinct environmental changes. Morphologically, remodeling was interpreted as the mechanical rearrangement of adsorbed FITC-labelled Col I into a fibril-like pattern. This process was strongly abrogated in cells cultured on oxidized Col I albeit without visible changes in cell morphology. Proteolytic activity was quantified utilizing fluorescence de-quenching (FRET effect). The presence of ADMSCs caused a significant increase in native FITC-Col I fluorescence, which was almost absent in the oxidized samples. Parallel studies in a cell-free system confirmed the enzymatic de-quenching of native FITC-Col I by Clostridial collagenase with statistically significant inhibition occurring in the oxidized samples. Structural changes to the oxidized Col I were further studied by differential scanning calorimetry. In the oxidized samples, an additional endotherm with sustained enthalpy (∆H) was observed at 33.6 °C along with Col I’s typical one at 40.5 °C. Collectively, these data support that the remodeling of Col I by ADMSCs is altered upon oxidation due to intrinsic changes to the protein’s structure, which represents a novel mechanism for the control of stem cell behavior.
Mesenchymal stem cells (MSCs) are involved in the process of extracellular matrix (ECM) remodeling where collagens play a pivotal role. We recently demonstrated that the remodeling of adsorbed collagen type I might be disordered upon oxidation following its fate in the presence of human adipose-derived MSC (ADMSCs). With the present study we intended to learn more about the effect of polyphenolic antioxidant Epigallocatechin-3-gallate (EGCG), attempting to mimic the conditions of oxidative stress in vivo and its putative prevention by antioxidants. Collagen Type I was isolated from mouse tail tendon (MTC) and labelled with FITC before being oxidized according to Fe2+/H2O2 protocol. FITC-collagen remodeling by ADMSC was assessed morphologically before and after EGCG pretreatment and confirmed via detailed morphometric analysis measuring the anisotropy index (AI) and fluorescence intensity (FI) in selected regions of interest (ROI), namely: outside the cells, over the cells, and central (nuclear/perinuclear) region, whereas the pericellular proteolytic activity was measured by de-quenching fluorescent collagen probes (FRET effect). Here we provide morphological evidence that MTC undergoes significant reorganization by the adhering ADMSC and is accompanied by a substantial activation of pericellular proteolysis, and further confirm that both processes are suppressed upon collagen oxidation. An important observation was that this abrogated remodeling cannot be prevented by the EGCG pretreatment. Conversely, the detailed morphometric analysis showed that oxidized FITC-collagen tends to accumulate beneath cells and around cell nuclei, suggesting the activation of alternative routes for its removal, such as internalization and/or transcytosis. Morphometric analysis also revealed that both processes are supported by EGCG pretreatment.
Recent studies have discovered that aryl-substituted pyrido[2,1-a]isoquinolines have the potential to be highly active DPP IV inhibitors. In previous studies, we reported a novel synthetic approach for the construction of their sulfur-containing bioisosteric [1,4]thiazino[3,4-a]isoquinolines analogues, incorporating an additional aryl substituent. The present study aims to investigate the DPP IV inhibitory activity and cytotoxicity of the synthesized molecules by in vitro assay. The geometry optimization and molecular docking of the synthesized compounds were used to determine their binding modes to the active site of DPP IV. The docking analysis revealed that the energy-minimized poses of the studied compounds are close to the most important selectivity cliffs for DPP IV inhibition, forming hydrogen bonds and hydrophobic interactions with them. These results can be considered as a preliminary step towards further structural activity modifications.
This study investigated changes in serum levels of protein glycation products, specifically fructosamine, methylglyoxal, and advanced glycation end products (AGEs), in rats with a chronic experimental model of type 2 diabetes induced by a high-fat diet and low-dose streptozotocin. Anthropometric, metabolic, and biochemical parameters were monitored. We observed an early and sustained increase in fructosamine and methylglyoxal, followed by a progressive accumulation of AGEs over the 28-week follow-up period. This experimental model enables the investigation of glycation products not only as biomarkers of disease development, severity, and complications but also as potential therapeutic targets through inhibition of their formation, enhancement of their clearance, or modulation of their receptor actions.
Background: Cardiovascular complications are a leading cause of death in patients with type 2 diabetes (T2D). The GLP-1 receptor agonist (GLP-1RA) semaglutide has shown cardiometabolic benefits in individual studies, but a comprehensive analysis of its effects in both oral and subcutaneous formulations is lacking. Objective: This study aimed to systematically evaluate the impact of semaglutide, in oral and subcutaneous formulations, on major adverse cardiovascular events (MACE) in patients with T2D. Methods: This review adhered to the PRISMA guidelines and included a comprehensive search of PubMed, MEDLINE, and Google Scholar from November 2016 to June 2025. High-quality randomized controlled trials (RCTs) comparing semaglutide with placebo in patients with T2D were included. The primary endpoint was MACE, defined as cardiovascular death, nonfatal myocardial infarction, and nonfatal stroke. Hazard ratio (HR) and 95% confidence intervals (CIs) were pooled using a random-effects model. Results: Of the 127 articles screened, 3 trials involving 16,130 participants met the inclusion criteria. The pooled HR for MACE across the SOUL, SUSTAIN-6, and PIONEER-6 trials was 0.83 (95% CI: 0.76–0.92; I2 = 25%), indicating a 17% relative risk reduction with low heterogeneity. Adverse event profiles were comparable between the semaglutide and placebo groups. Conclusions: Semaglutide use was associated with a significant and consistent reduction in MACE in patients with T2D, supporting its role as a valuable therapeutic option for combined glycemic control and cardiovascular risk reduction.