Search Results (64)

In the pursuit of novel anticancer therapies, assessing their selectivity and safety profile towards healthy cells is crucial. This study investigated chlorochalcones, derivatives of 2′-hydroxychalcone containing a chlorine atom, for their impact on human breast cancer cells (MCF-7 and MDA-MB-231), healthy blood cells (erythrocytes, peripheral blood mononuclear cells (PBMCs), platelets), and microvascular endothelial cells (HMEC-1). Our findings demonstrated that chlorochalcones did not detrimentally affect erythrocytes, showing no hemolysis or preserving osmotic resistance and transmembrane potential. They also exhibited minimal impact on normal PBMC viability and varying effects on platelet metabolic activity at therapeutic concentrations. Importantly, these derivatives displayed lower toxicity towards HMEC-1 endothelial cells than towards breast cancer cells, indicating a degree of selectivity. Chlorochalcones have high antiproliferative activity against cancer cells, primarily by inducing apoptosis with virtually no significant impact on cell cycle progression. Their mechanism of action involves the modulation of reactive oxygen species (ROS) levels and induction of mitochondrial dysfunction, including membrane depolarization and reduced mitochondrial mass. Biological activity, including toxicity and ROS modulation, is dependent on the position and number of chlorine atoms. In conclusion, this study highlights the ability of chlorochalcones to effectively target malignant cells while sparing normal circulatory and endothelial cells, thus positioning them as a promising class of candidates for further anticancer drug development. Full article

The increasing demand for smart bone substitutes has boosted the implementation of biomaterials possibly endowed with both pro-osteogenic and pro-angiogenic capabilities, among which bioactive glasses hold great potential. Hence, two Poly(ε-caprolactone) (PCL)-based composites were loaded at 10 wt.%, with either pristine (SBA3) or copper-doped (SBA3_Cu) silica-based bioactive glasses, through a solvent casting method with chloroform. Neat PCL was used as a control. Samples produced by 3D printing underwent SEM and EDX analyses, and the following were measured: tensile strength and hardness, surface roughness, ion release through ICP-OES, surface free energy, and optical contact angle. Adipose-derived mesenchymal stem cells (ASCs) and human microvascular endothelial cells (HMEC-1) were used to test the biocompatibility of the materials through cell adhesion, spreading, and viability assays. A significant improvement in tensile strength and hardness was observed especially with Cu-doped composites. Both SBA3 and SBA3_Cu added to the PCL favored the early adhesion and the proliferation of HMEC-1 after 3 and 7 days, while ASCs proliferated significantly the most on the SBA-containing composite, at all the time points. Cellular morphology analysis highlighted interesting adaptation patterns to the samples. Further biological characterizations are needed to understand thoroughly how specific bioactive glasses may interact with different cellular types. Full article

Background/Objectives: Angiogenesis is the multistep process of the formation of new blood vessels. It is beneficial in scenarios that require tissue repair and regeneration, such as wound healing, bone fracture repair, and recovery from ischemic injuries like stroke, where new blood vessel formation restores oxygen and nutrient supply to damaged areas. Extremely low-frequency electromagnetic stimulation (ELF-EMS), which involves electromagnetic fields in the frequency range of 0–300 Hz, have been shown to reduce ischemic stroke volume by improving cerebral blood flow and recovery effects that are dependent on eNOS. Based on previous results, we herein explore the effects of ELF-EMS treatment (13.5 mT/10 and 60 Hz) on the activation of angiogenic processes in vitro in homeostatic conditions. Methods: Using human microvascular endothelial cells (HMEC-1), we studied cell proliferation, migration, and tube formation in vitro, as well as nitric oxide production and the effect of calcium and nitric oxide (NO) on these processes. Moreover, blood vessel formation was studied using a chicken chorioallantoic membrane (CAM) assay. Results: Our results showed that ELF-EMS increases proliferation, tube formation, and both the migration and transmigration of these cells, the latter of which was mediated via NO. In turn, calcium inhibition decreased ELF-EMF-induced NO production. Furthermore, ELF-EMS significantly increased blood vessel formation in the CAM assay. Conclusions: Our results indicated that ELF-EMS exposure (13.5 mT/10 and 60 Hz) significantly induces angiogenesis in vitro and in ovo, underscoring its potential application in the treatment of conditions characterized by insufficient blood supply. Full article

The role of periodontal ligament stem cells (PDLSCs) and dental pulp stem cells (DPSCs) in stimulating angiogenesis has been reported, but their angiogenetic potential has not been directly compared. In this work, paired PDLSCs and DPSCs, i.e., derived from the same donor, were tested for their immunophenotype and multi-differentiation capabilities, with particular emphasis on their pro-angiogenic activity. Flow cytometry was utilized to study the expression of mesenchymal stem cell, pericyte, and endothelial markers, while gene expression was evaluated through real-time PCR. The angiogenic potential was assessed recurring to tubulogenesis assay, co-cultures with Human Microvascular Endothelial Cell (HMEC-1), and VEGF-A quantification. The immunophenotype of DPSCs and PDLSCs was different in CD146+ and CD31+ cell subsets, but both cell types promoted HMEC-1 tubulogenesis in vitro. Consistently, VEGF-A gene expression level and its quantification in cell-conditioned media of PDLSCs and DPSCs was comparable between them, and both promoted the formation of vessel-like structures, when co-cultured with HMEC-1 cells. All together, these results showed the heterogeneity of PDLSCs and DPSCs, which are constituted of different cellular subsets, likely modulated by the microenvironmental cues. PDLSCs and DPSCs showed comparable pro-angiogenic activity, enhanced by the contemporary expression of angiogenic and chemotactic factors. Full article

Recent advances in the clinical extracellular vesicles (EVs) field highlight their potential as biomarkers for diverse diseases and therapeutic applications. This study provides an in-depth characterization of 10k EVs from human microvascular endothelial cells (HMEC-1) exposed to benzo[a]pyrene (B[a]P), a polycyclic aromatic hydrocarbon found in food and smoke. Given EVs’ complexity, with numerous surface and cargo proteins, phenotyping remains challenging. Here, we introduce a multiplex biosensor, in µarray format, for profiling EVs from distinct cellular conditions, employing a multimodal approach that combines surface plasmon resonance imaging (SPRi) and in situ atomic force microscopy (AFM) to decipher EVs’ biochemical and biophysical properties. SPRi experiments showed notable EV capture differences on ligands such as Anti-CD36, Anti-CD81, and Anti-ApoA between treated and control conditions, likely due to B[a]P exposure. A complementary AFM study and statistical analyses revealed size differences between EVs from treated and control samples, with ligands like Annexin-V, Anti-CD36, and Anti-VEGFR1 emerging as ligands specific to potential cytotoxicity biomarkers. Our findings suggest that B[a]P exposure may increase EV size and alter marker expression, indicating phenotypic shifts in EVs under cytotoxic stress. The original combination of SPRi and AFM reveals valuable data on the phenotypical and morphological heterogeneities of EV subsets linked to cytotoxic stresses and highlights the potential of EVs as specific toxicological markers. Full article

Palladium(II) complexes with tris(2-carboxyethyl)phosphine (PdTCEP) show promise for biomedical applications due to their distinct chemical characteristics. This study explored the toxicity of PdTCEP towards normal human cells and examined its interactions with model cell membranes. Two cell types were used to evaluate cytotoxicity: human microvascular endothelial cells (HMEC-1) and red blood cells (RBCs). In HMEC-1 cells, PdTCEP reduced survival to about 80% at 15 µM, with the most significant drop—down to 40%—occurring at 40 µM. The production of reactive oxygen species (ROS) increased in a manner dependent on both dose and time, especially after 72 h of incubation. Despite these effects, PdTCEP caused only minor hemolysis in RBCs, with hemolysis levels staying below 10% even at higher concentrations. Fluorescence anisotropy measurements showed that PdTCEP minimally affects the hydrophobic core of the lipid bilayer, with slight changes observed at concentrations above 40 µM. Generalized polarization (GP) analysis indicated a slight decrease in lipid polar head packing with increasing PdTCEP concentration. Complementary FTIR analysis supported these findings by providing detailed insights into PdTCEP-membrane interactions. This research underscores PdTCEP’s selective cytotoxicity and structural effects on membranes, suggesting its promise for more in-depth biological and pharmacological studies. Full article

Endothelin-1 is a key regulator of vascular tone and blood pressure in health and disease. We have recently found that ET-1 production in human microvascular endothelial cells (HMECs) can be promoted by angiotensin II (Ang II) through a novel mechanism involving octamer-binding transcription factor-1 (Oct-1), NADPH oxidase-2 (NOX2), and superoxide anions. As the formation of bioactive ET-1 also depends on endothelin-converting enzyme-1 (ECE-1), we investigated the transcriptional regulation of the ECE1 gene. We found that exposure of HMECs to Ang II resulted in a concentration- and time-dependent increase in ECE1 mRNA expression. Pharmacological inhibition of ECE-1 reduced Ang II-stimulated ET-1 release to baseline values. The effect of Ang II on ECE1 mRNA expression was associated with Oct-1 binding to the ECE1 promoter, resulting in its increased activity. Consequently, the Ang II-stimulated increase in ECE1 mRNA expression could be prevented by siRNA-mediated Oct-1 inhibition. It could also be abolished by silencing the NOX2 gene and neutralizing superoxide anions with superoxide dismutase. In mice fed a high-fat diet, cardiac expression of Ece1 mRNA increased in wild-type mice but not in Nox2-deficient animals. It can be concluded that Ang II engages Oct-1, NOX2, and superoxide anions to stimulate ECE1 expression in the endothelium. Full article

Vascular complications in Type 2 diabetes mellitus (T2DM) patients increase morbidity and mortality. In T2DM, angiogenesis is impaired and can be enhanced or reduced in different tissues (“angiogenic paradox”). The present study aimed to delineate differences between macrovascular and microvascular endothelial cells that might explain this paradox. In a monoculture system of human macrovascular (EaHy926) or microvascular (HMEC-1) endothelial cell lines and a monocytic cell line (U937), high glucose concentrations (25 mmole/L) increased the secretion of the pro-angiogenic factors CD147/EMMPRIN, VEGF, and MMP-9 from both endothelial cells, but not from monocytes. Co-cultures of EaHy926/HMEC-1 with U937 enhanced EMMPRIN and MMP-9 secretion, even in low glucose concentrations (5.5 mmole/L), while in high glucose HMEC-1 co-cultures enhanced all three factors. EMMPRIN mediated these effects, as the addition of anti-EMMPRIN antibody decreased VEGF and MMP-9 secretion, and inhibited the angiogenic potential assessed through the wound assay. Thus, the minor differences between the macrovascular and microvascular endothelial cells cannot explain the angiogenic paradox. Metformin, a widely used drug for the treatment of T2DM, inhibited EMMPRIN, VEGF, and MMP-9 secretion in high glucose concentration, and the AMPK inhibitor dorsomorphin enhanced it. Thus, AMPK regulates EMMPRIN, a key factor in diabetic angiogenesis, suggesting that targeting EMMPRIN may help in the treatment of diabetic vascular complications. Full article

To better understand radiation-induced organ dysfunction at both high and low doses, it is critical to understand how endothelial cells (ECs) respond to radiation. The impact of irradiation (IR) on ECs varies depending on the dose administered. High doses can directly damage ECs, leading to EC impairment. In contrast, the effects of low doses on ECs are subtle but more complex. Low doses in this study refer to radiation exposure levels that are below those that cause immediate and necrotic damage. Mitochondria are the primary cellular components affected by IR, and this study explored their role in determining the effect of radiation on microvascular endothelial cells. Human dermal microvascular ECs (HMEC-1) were exposed to varying IR doses ranging from 0.1 Gy to 8 Gy (~0.4 Gy/min) in the AFRRI 60-Cobalt facility. Results indicated that high doses led to a dose-dependent reduction in cell survival, which can be attributed to factors such as DNA damage, oxidative stress, cell senescence, and mitochondrial dysfunction. However, low doses induced a small but significant increase in cell survival, and this was achieved without detectable DNA damage, oxidative stress, cell senescence, or mitochondrial dysfunction in HMEC-1. Moreover, the mitochondrial morphology was assessed, revealing that all doses increased the percentage of elongated mitochondria, with low doses (0.25 Gy and 0.5 Gy) having a greater effect than high doses. However, only high doses caused an increase in mitochondrial fragmentation/swelling. The study further revealed that low doses induced mitochondrial elongation, likely via an increase in mitochondrial fusion protein 1 (Mfn1), while high doses caused mitochondrial fragmentation via a decrease in optic atrophy protein 1 (Opa1). In conclusion, the study suggests, for the first time, that changes in mitochondrial morphology are likely involved in the mechanism for the radiation dose-dependent effect on the survival of microvascular endothelial cells. This research, by delineating the specific mechanisms through which radiation affects endothelial cells, offers invaluable insights into the potential impact of radiation exposure on cardiovascular health. Full article

Chronic hyperglycemia and oxidative stress in Type 2 Diabetes Mellitus trigger cellular dysfunction via the formation of Advanced Glycation End Products (AGEs), resulting in dicarbonyl stress. Glyoxalase-1 (Glo-1) is the main defense against dicarbonyl stress. The aim of this study was to explore any cross-talk between Glo-1 and markers of hyperglycemia and oxidative stress. The siRNA-mediated downregulation of Glo-1 was performed in human microvascular endothelial cell line (HMEC-1). A Glo-1 transgenic rat model was developed. Glo-1 activity, as determined spectrophotometrically, and methylglyoxal were quantified using UPLC-MS/MS and the expression of representative markers of hyperglycemia and oxidative stress was performed using quantitative real-time PCR. A significant increase in the expression of Vascular Cell Adhesion Molecule-1 (VCAM-1) was observed in the case of the siRNA-mediated downregulation of Glo-1 in the microvasculature model under hyperglycemic conditions (p-value < 0.001), as well the as overexpression of Glo-1 in the macrovasculature (p-value = 0.0125). The expression of thioredoxin interacting protein (TXNIP) was found to be significantly upregulated in wildtype diabetic conditions vs. Glo-1 transgenic control conditions (p-value = 0.008), whereas the downregulation of Glo-1 had no impact on TXNIP expression. These findings substantiate the role of VCAM as an important marker of dicarbonyl stress (represented by Glo-1 downregulation), as well as of hyperglycemia, in diabetic vascular complications. Our findings also suggest a potential feedback loop that may exist between Glo-1 and TXNIP, as the highest expression of TXNIP is observed in cases of wildtype diabetic conditions, and the lowest expression of TXNIP is observed when Glo-1 transgene is being expressed in absence of dicarbonyl stress. Full article

Green microalgae are single-celled eukaryotic organisms that, in recent years, are becoming increasingly important in the nutraceutical, cosmetic, and pharmaceutical fields because of their high content of bioactive compounds. In this study, a particular green microalga was isolated from freshwater highland lakes of Ecuador and morphologically and molecularly identified as Chlamydomonas agloeformis (ChA), and it was studied for nutritional and nutraceutical properties. The phenolic composition and the fatty acids profile of lyophilized cells were determined. The methanolic extract was analyzed for the phenolic compounds profile and the antioxidant capacity by means of in vitro tests. Finally, Human Microvascular Endothelial Cells (HMEC-1) were exploited to explore the capacity of ChA to reduce the endothelial damage induced by oxidized LDL-mediated oxidative stress. The extract showed a good antioxidant ability thanks to the high content in polyphenolic compounds. The observed decrease in HMEC-1 cells endothelial damage also was probably due to the antioxidant compounds present in the extract. Based on the outcomes of our in vitro assays, ChA demonstrated to be a promising source of bioactive compounds possessing exceptional antioxidant capacities which make it a prospective functional food. Full article

Surgery, radiotherapy, and chemotherapy are essential treatment modalities to target cancer cells, but they frequently cause damage to the normal tissue, potentially leading to side effects. As proton beam radiotherapy (PBT) can precisely spare normal tissue, this therapeutic option is of increasing importance regarding (neo-)adjuvant and definitive anti-cancer therapies. Akin to photon-based radiotherapy, PBT is often combined with systemic treatment, such as doxorubicin (Dox). This study compares the cellular response of human microvascular endothelial cells (HMEC-1) following irradiation with photons (X) or protons (H) alone and also in combination with different sequences of Dox. The cellular survival, cell cycle, apoptosis, proliferation, viability, morphology, and migration were all investigated. Dox monotreatment had minor effects on all endpoints. Both radiation qualities alone and in combination with longer Dox schedules significantly reduced clonogenic survival and proliferation, increased the apoptotic cell fraction, induced a longer G2/M cell cycle arrest, and altered the cell morphology towards endothelial-to-mesenchymal-transition (EndoMT) processes. Radiation quality effects were seen for metabolic viability, proliferation, and motility of HMEC-1 cells. Additive effects were found for longer Dox schedules. Overall, similar effects were found for H/H-Dox and X/X-Dox. Significant alterations between the radiation qualities indicate different but not worse endothelial cell damage by H/H-Dox. Full article

Recently, green microalgae have gained importance due to their nutritional and bioactive compounds, which makes them some of the most promising and innovative functional foods. The aim of this study was to evaluate the chemical profile and the in vitro antioxidant, antimicrobial and antimutagenic activity of an aqueous extract of the green microalga Ettlia pseudoalveolaris, obtained from the freshwater lakes of the Ecuadorian Highlands. Human microvascular endothelial cells (HMEC-1) were used to determine the ability of the microalga to reduce the endothelial damage caused by hydrogen peroxide-induced oxidative stress. Furthermore, the eukaryotic system Saccharomyces cerevisiae was used to evaluate the possible cytotoxic, mutagenic and antimutagenic effect of E. pseudoalveolaris. The extract showed a notable antioxidant capacity and a moderate antibacterial activity mostly due to the high content in polyphenolic compounds. It is likely that the antioxidant compounds present in the extract were also responsible for the observed reduction in endothelial damage of HMEC-1 cells. An antimutagenic effect through a direct antioxidant mechanism was also found. Based on the results of in vitro assays, E. pseudoalveolaris proved to be a good source of bioactive compounds and antioxidant, antibacterial and antimutagenic capacities making it a potential functional food. Full article

Sea urchins have emerged as an important source of bioactive compounds with anti-inflammatory and antioxidant properties relevant to human health. Since inflammation is a crucial pathogenic process in the development and progression of atherosclerosis, we here assessed the potential anti-inflammatory and vasculoprotective effects of coelomic red-cell methanolic extract of the black sea urchin Arbacia lixula in an in vitro model of endothelial cell dysfunction. Human microvascular endothelial cells (HMEC-1) were pretreated with A. lixula red-cell extract (10 and 100 μg/mL) before exposure to the pro-inflammatory cytokine tumor necrosis factor (TNF)-α. The extract was non-toxic after 24 h cell treatment and was characterized by antioxidant power and phenol content. The TNF-α-stimulated expression of adhesion molecules (VCAM-1, ICAM-1) and cytokines/chemokines (MCP-1, CCL-5, IL-6, IL-8, M-CSF) was significantly attenuated by A. lixula red-cell extract. This was functionally accompanied by a reduction in monocyte adhesion and chemotaxis towards activated endothelial cells. At the molecular level, the tested extract significantly counteracted the TNF-α-stimulated activation of the pro-inflammatory transcription factor NF-κB. These results provide evidence of potential anti-atherosclerotic properties of A. lixula red-cell extract, and open avenues in the discovery and development of dietary supplements and/or drugs for the prevention or treatment of cardiovascular diseases. Full article

The oleo–gum resin of Commiphora myrrha (Nees) Engl. has a long history of medicinal use, although many of its constituents are still unknown. In the present investigation, 34 secondary metabolites were isolated from myrrh resin using different chromatographic techniques (silica flash chromatography, CPC, and preparative HPLC) and their structures were elucidated with NMR spectroscopy, HRESIMS, CD spectroscopy, and ECD calculations. Among the isolated substances are seven sesquiterpenes (1–7), one disesquiterpene (8), and two triterpenes (23, 24), which were hitherto unknown, and numerous substances are described here for the first time for C. myrrha or the genus Commiphora. Furthermore, the effects of selected terpenes on cervix cancer cells (HeLa) were studied in an MTT-based in vitro assay. Three triterpenes were observed to be the most toxic with moderate IC₅₀ values of 60.3 (29), 74.5 (33), and 78.9 µM (26). Due to the different activity of the structurally similar triterpenoids, the impact of different structural elements on the cytotoxic effect could be discussed and linked to the presence of a 1,2,3-trihydroxy substructure in the A ring. The influence on TNF-α dependent expression of the intercellular adhesion molecule 1 (ICAM-1) in human microvascular endothelial cells (HMEC-1) was also tested for 4–6, 9–11, 17, 18, 20, and 27 in vitro, but revealed less than 20% ICAM-1 reduction and, therefore, no significant anti-inflammatory activity. Full article