Search Results (698)

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive interstitial lung disease with limited therapeutic options and increasing global incidence, with a median survival of only 2–5 years. The clinical utility of macrophage polarization to regulate the progression of pulmonary fibrosis remains understudied. This study determined the efficacy of nintedanib and pexidartinib (PLX3397) combination therapy for treating IPF. Combination treatment effectively inhibited the progression of radiation-induced pulmonary fibrosis (RIPF) and prolonged survival in bleomycin-treated mice. Micro-CT analysis revealed a significant tissue repair efficacy. The therapy significantly normalized the abnormal vascular structure observed during RIPF and bleomycin-induced pulmonary fibrosis progression and was accompanied by a decrease in the M2 population. Polarized M1 macrophages enhanced normalized tube formation of irradiated endothelial cells (ECs) in vitro; M2 macrophages increased adhesion in irradiated ECs and abnormal tube formation. Single-cell RNA sequencing data from patients with IPF further supports colony stimulating factor (CSF) 1 upregulation in macrophages and downregulation of capillary EC markers. This study highlights a promising combination strategy to overcome the therapeutic limitations of monotherapy with nintedanib for the treatment of IPF. Full article

Fine particulate matter (PM_2.5) exposure has been linked to increased lung damage due to compromised vascular barrier function, while 3-deoxysappanchalcone (3-DSC), a chalcone derived from Caesalpinia sappan, is known for its pharmacological benefits such as anti-cancer, anti-inflammatory, and antioxidant effects; however, its potential role in mitigating PM_2.5-induced pulmonary damage remains unexplored. To confirm the inhibitory effects of 3-DSC on PM_2.5-induced pulmonary injury, this research focused on evaluating how 3-DSC influences PM_2.5-induced disruption of the barrier of the endothelial cells (ECs) in the lungs and the resulting pulmonary inflammation. Permeability, leukocyte migration, proinflammatory protein activation, reactive oxygen species (ROS) generation, and histology were assessed in PM_2.5-treated ECs and mice. This study demonstrated that 3-DSC effectively neutralized the reactive oxygen species (ROS) generated by PM_2.5 exposure in the lung endothelial cells, suppressing ROS-triggered p38 MAPK activation while enhancing Akt signaling pathways critical to preserving vascular barrier function. In animal models, 3-DSC administration markedly decreased vascular permeability, attenuated the influx of immune cells into the lung tissue, and lowered inflammatory mediators like cytokines in the airways of PM_2.5-exposed mice. These data suggest that 3-DSC might exert protective effects on PM_2.5-induced inflammatory lung injury and vascular hyperpermeability. Full article

Estrogens regulate many physiological processes in the human body, including the cardiovascular system. Importantly, Estradiol (E2) exerts its vascular protective actions, in part, by promoting endothelial repair via induction of endothelial cell (EC) proliferation, migration and angiogenesis. Recent evidence that microRNAs (miRNAs) play an important role in vascular health and disease as well as in regulating Estrogen actions in many cell types. We hypothesize that E2 may mediate its vascular protective actions via the regulation of miRNAs. Following initial screening, we found that E2 downregulates the levels of miR-193a-3p in ECs. Moreover, miR-193a-3p downregulation by miR-193a-3p-antimir mimicked the effects as E2 on EC growth, migration, and capillary formation. Restoring miR-193a-3p levels with mimics after E2 treatment abrogated the vasculogenic actions of E2, suggesting a key role of miR-193a-3p in E2-mediated EC-growth-promoting effects. We further investigated the cellular mechanisms involved and found that miR-193a-3p inhibits angiogenesis by blocking phosphoinositide-3-kinase (PI3K)/Akt-vascular endothelial growth factor (VEGF) and Activin receptor-like kinase 1 (ALK1)/SMAD1/5/8 signaling in ECs, both pathways that are important in E2-mediated vascular protection. Additionally, using reverse transcription polymerase chain reaction (RT-PCR), we demonstrate that E2 downregulates miR-193a-3p in ECs via Estrogen Receptor (ER)α, but not ERβ or G protein-coupled estrogen receptor (GPER). Moreover, these actions occur post-transcriptionally, as the expression of pri-miR-193a-3p was not affected. The anti-angiogenic actions of miR-193a-3p were also observed in in vivo Matrigel implant-based capillary formation studies in ovariectomized mice where E2 induced capillary formation, and these effects were abrogated in the presence of miR-193a-3p, but not in the control mimic. Assessment of miR-193a-3p levels in plasma collected from in vitro fertilization (IVF) subjects with low and high E2 levels showed significantly lower miR-193a-3p levels in responders during the high E2 period. Hence, our findings provide the first evidence that miR-193a-3p mimic inhibits angiogenesis whereas its antimir is angiogenic. Importantly, E2 mediates its regenerative actions on ECs/capillary formation by downregulating endogenous miR-193a-3p expression. Both miR-193a-3p mimic or antimir may represent important therapeutic molecules to prevent or to induce endothelial function in treating pathophysiologies associated with capillary growth. Full article

Deposition of intramuscular fat (IM), also known as marbling, is the deciding factor of beef quality grade in the U.S. Defining molecular mechanisms underlying the differential deposition of adipose tissue in distinct anatomical areas in beef cattle is key to the development of strategies for marbling enhancement while limiting the accumulation of excessive subcutaneous adipose tissue (SAT). The objective of this exploratory study was to define the IM and SAT transcriptional heterogeneity at the whole tissue and single-nuclei levels in beef steers. Longissimus dorsi muscle samples (9–11th rib) were collected from two finished beef steers at harvest to dissect matched IM and adjacent SAT (backfat). Total RNA from IM and SAT was isolated and sequenced in an Illumina NovaSeq 6000. Nuclei from the same samples were isolated by dounce homogenization, libraries generated with 10× Genomics, and sequenced in an Illumina NovaSeq 6000, followed by analysis via Cell Ranger pipeline and Seurat in RStudio (v4.3.2) By the expression of signature marker genes, single-nuclei RNA sequencing (snRNAseq) analysis identified mature adipocytes (AD; ADIPOQ, LEP), adipose stromal and progenitor cells (ASPC; PDGFRA), endothelial cells (EC; VWF, PECAM1), smooth muscle cells (SMC; NOTCH3, MYL9) and immune cells (IMC; CD163, MRC1). We detected six cell clusters in SAT and nine in IM. Across IM and SAT, AD was the most abundant cell type, followed by ASPC, SMC, and IMC. In SAT, AD made up 50% of the cellular population, followed by ASPC (31%), EC (14%), IMC (1%), and SMC (4%). In IM depot, AD made up 23% of the cellular population, followed by ASPC at 19% of the population, EC at 28%, IMC at 7% and SMC at 12%. The abundance of ASPC and AD was lower in IM vs. SAT, while IMC was increased, suggesting a potential involvement of immune cells on IM deposition. Accordingly, both bulk RNAseq and snRNAseq analyses identified activated pathways of inflammation and metabolic function in IM. These results demonstrate distinct transcriptional cellular heterogeneity between SAT and IM depots in beef steers, which may underly the mechanisms by which fat deposits in each depot. The identification of depot-specific cell populations in IM and SAT via snRNAseq analysis has the potential to reveal target genes for the modulation of fat deposition in beef cattle. Full article

The endothelial glycocalyx (GCX) plays a crucial role in vascular health and integrity and influences many biochemical activities through mechanotransduction, in which heparan sulfate (HS) plays a major role. Endothelin-1 (ET-1) is a potent vasoregulator that binds to the endothelin B receptor (ETB) on endothelial cells (ECs), stimulating vasodilation, and to the endothelin A receptor on smooth muscle cells, stimulating vasoconstriction. While the shear stress (SS) dependence of ET-1 and HS is well documented, there is limited research documenting the SS dependence of the ETB. Understanding the SS dependence of the ETB is crucial for clarifying the role of hemodynamic forces in the endothelin system. We hypothesize that GCX HS regulates the expression of the ETB on the EC surface in an SS-dependent manner. Human lung microvascular ECs were exposed to SS in a parallel-plate flow chamber for 12 h. Damage to the GCX was simulated by treatment with 15 mU/mL heparinase-III during SS exposure. Immunostaining and qPCR were used to evaluate changes in ET-1, ETB, and HS expression. Results indicate that ETB expression is SS sensitive, with at least a 1.3-fold increase in ETB protein expression and a 0.6 to 0.4-fold-change decrease in ETB mRNA expression under SS. This discrepancy suggests post-translational regulation. In some cases, enzymatic degradation of HS attenuated the SS-induced increase in ETB protein, reducing the fold-change difference to 1.1 relative to static controls. This implies that ETB expression may be partially dependent on HS-mediated mechanotransduction, though inconclusively. Furthermore, ET-1 mRNA levels were elevated two-fold under SS without a corresponding rise in ET-1 protein expression or significant impact from HS degradation, implying that post-translational regulation of ET-1 occurs independently of HS. Full article

Arteriovenous malformations (AVMs) are congenital vascular anomalies defined by abnormal direct connections between arteries and veins due to their complex structure or endovascular approaches. Pharmacological strategies targeting the underlying molecular mechanisms are thus gaining increasing attention in an effort to determine the mechanism involved in AVM regulation. In this study, we examined 30 human tissue samples, comprising 10 vascular samples, 10 human fibroblasts derived from AVM tissue, and 10 vascular samples derived from healthy individuals. The pharmacological agents thalidomide, U0126, and rapamycin were applied to the isolated endothelial cells (ECs). The pharmacological treatments reduced the proliferation of AVM ECs and downregulated miR-135b-5p, a biomarker associated with AVMs. The expression levels of angiogenesis-related genes, including VEGF, ANG2, FSTL1, and MARCKS, decreased; in comparison, CSPG4, a gene related to capillary networks, was upregulated. Following analysis of these findings, skin samples from 10 AVM patients were reprogrammed into induced pluripotent stem cells (iPSCs) to generate AVM blood vessel organoids. Treatment of these AVM blood vessel organoids with thalidomide, U0126, and rapamycin resulted in a reduction in the expression of the EC markers CD31 and α-SMA. The establishment of AVM blood vessel organoids offers a physiologically relevant in vitro model for disease characterization and drug screening. The authors of future studies should aim to refine this model using advanced techniques, such as microfluidic systems, to more efficiently replicate AVMs’ pathology and support the development of personalized therapies. Full article

Atherosclerosis (AS), a progressive inflammatory disease of coronary arteries, the aorta, and the internal carotid artery, is considered one of the main contributors to cardiovascular disorders. Blood flow is restricted by accumulating lipid-rich macrophages (foam cells), calcium, fibrin, and cellular debris into plaques on the intima of arterial walls. Butyrate maintains gut barrier integrity and modulates immune responses. Butyrate regulates G-protein-coupled receptor (GPCR) signaling and activates nuclear factor kappa-B (NF-κB), activator protein-1 (AP-1), and interferon regulatory factors (IFRs) involved in the production of proinflammatory cytokines. Depending on the inflammatory stimuli, butyrate may also inactivate NF-κB, resulting in the suppression of proinflammatory cytokines and the stimulation of anti-inflammatory cytokines. Butyrate modulates mitogen-activated protein kinase (MAPK) to promote or suppress macrophage inflammation, muscle cell growth, apoptosis, and the uptake of oxidized low-density lipoprotein (ox-LDL) in macrophages. Activation of the peroxisome proliferator-activated receptor γ (PPARγ) pathway plays a role in lipid metabolism, inflammation, and cell differentiation. Butyrate inhibits interferon γ (IFN-γ) signaling and suppresses NOD-, LRR-, and pyrin domain-containing protein 3 (NLRP3) involved in inflammation and scar tissue formation. The dual role of butyrate in AS is discussed by addressing the interactions between butyrate, intestinal epithelial cells (IECs), endothelial cells (ECs) of the main arteries, and immune cells. Signals generated from these interactions may be applied in the diagnosis and intervention of AS. Reporters to detect early AS is suggested. This narrative review covers the most recent findings published in PubMed and Crossref databases. Full article

This study aims to investigate the mechanism by which the total flavones of Rhododendron (TFR) protect against cerebral ischemic injury through the endothelial-derived H₂S-mediated regulation of RhoA phosphorylation at the Ser188 and Rho kinase 2 (ROCK₂) phosphorylation at Thr436. For experimental design, mouse or rat cerebrovascular endothelial cells (ECs) were cultured with or without neurons and subjected to hypoxia/reoxygenation (H/R) injury. The vasodilation of the cerebral basilar artery was assessed. Cerebral ischemia/reperfusion (I/R) injury was induced in mice by bilateral carotid artery ligation, followed by Morris water maze and open field behavioral assessments. The protein levels of cystathionine-γ-lyase (CSE), 3-mercaptopyruvate sulfurtransferase (3-MST), RhoA, ROCK₂, p-RhoA (RhoA phosphorylated at Ser188), and p-ROCK₂ (ROCK₂ phosphorylated at Thr436) were quantified. Additionally, the activities of RhoA and ROCK₂ were measured. Notably, TFR significantly inhibited H/R-induced H₂S reduction and suppressed the increased expression and activity of RhoA and ROCK₂ in ECs, effects attenuated by CSE or 3-MST knockout. Moreover, TFR-mediated cerebrovascular dilation was reduced by RhoA or ROCK₂ inhibitors, while the protective effect of TFR against cerebral I/R injury in mice was markedly attenuated by the heterozygous knockout of ROCK₂. In the ECs-co-cultured neurons, the inhibition of TFR on H/R-induced neuronal injury and decrease in H₂S level in the co-culture was attenuated by the knockout of CSE or 3-MST in the ECs. TFR notably inhibited the H/R-induced upregulation of neuronal RhoA, ROCK₂, and p-ROCK₂ protein levels, as well as the activities of RhoA and ROCK₂, while reversing the decrease in p-RhoA. However, the knockout of CSE or 3-MST in the ECs significantly attenuated the inhibition of TFR on these increases. Furthermore, 3-MST knockout in ECs attenuated the TFR-mediated suppression of p-RhoA reduction. Additionally, CSE or 3-MST knockout in ECs exacerbated H/R-induced neuronal injury, reduced H₂S level in the co-culture system, and increased RhoA activity and ROCK₂ expression in neurons. In summary, TFR protected against ischemic cerebral injury by endothelial-derived H₂S promoting the phosphorylation of RhoA at Ser188 but inhibited the phosphorylation of ROCK₂ at Thr436 to inhibit the RhoA-ROCK₂ pathway in neurons. Full article

Background: Intercellular communication, facilitated by exosomes (Exos) derived from endothelial cells (ECs), significantly influences the regulation of angiogenesis. Leech extract significantly reduces ischemia–reperfusion injury, promotes angiogenesis, and improves neurological function in mice with stroke. However, further investigation is required to determine whether leech promotes angiogenesis through EC-Exo. Objective: This study aims to further explore whether leech regulates Exos to promote the establishment of collateral circulation in mice with ischemic stroke (IS) and the specific mechanisms involved. Methods: Here, we utilized an in vitro co-culture system comprising ECs and pericytes to investigate the impact of Leech-EC-Exo on enhancing the proliferation and migration of mouse brain microvascular pericytes (MBVPs). We further established an in vivo mouse model of middle cerebral artery occlusion/reperfusion (MCAO/R) to investigate the effects and underlying mechanisms of leech on collateral circulation establishment. Results: The findings demonstrated that leech significantly enhanced the in vitro cell migration number and migration number of pericytes. Therefore, it can also enhance the effect of EC-Exo on improving the infarct area and gait of mice, as well as modulating the HIFα-VEGF-DLL4-Notch1 signaling pathway to promote cerebral angiogenesis and facilitating the stable maturation of neovascularization in vivo. Conclusions: These results suggest that leech has the potential to enhance collateral circulation establishment, and its mechanism may involve the modulation of miRNA content in Exos and the promotion of signaling pathways associated with angiogenesis and vascular maturation. Full article

Poloxamer (P) 188 attenuates myocardial ischemia/reperfusion injury through cell membrane stabilization. Cell–cell interactions between endothelial cells (ECs) and cardiomyocytes (CMs) further protect CMs: co-cultures showed that, at an optimal density, ECs protected CMs against hypoxia/reoxygenation (HR) injury. The mechanism of interaction with P188 still requires exploration. We examined if N(ω)-nitro-L-arginine methyl ester (LNAME), a non-specific nitric oxide (NO) synthase inhibitor, abolishes protection in the presence or absence of P188 and/or ECs. We co-cultured mouse coronary artery ECs in an insert atop mouse CMs plated at confluency on the bottom of a well. Normoxic controls remained in complete media while HR groups were exposed to 24 h hypoxia at 0.01% O₂ in serum- and glucose-free media, followed by 2 h reoxygenation in complete media. P188 (300 μM), LNAME (40 mM), or vehicle were administered upon reoxygenation. ECs at the used lower density did not decrease HR-triggered lactate dehydrogenase release or calcium overload in CMs by themselves. P188 reduced both indicators after HR by 16/18% without and by 22/25% with ECs, respectively. LNAME abrogated CM protection by P188. Neither intervention had an effect under normoxia. Our co-culture data indicates that P188 requires NO, not necessarily of endothelial origin, to elicit CM protection. Full article

Compelling clinical evidence strongly indicates that anti-angiogenesis therapeutics including Bevacizumab, a humanised anti-VEGF mAb, can alleviate the resistance to immunotherapy. We explored the direct modulation of Bevacizumab on endothelial cell (EC) immune response including surface expression of adhesion and MHC molecules and EC-elicited proliferation of immune cells under inflammatory conditions. Flow cytometry showed that addition of VEGF inhibited TNF-α stimulation of expression of ICAM-1 and VCAM-1 on HUVECs, whereas Bevacizumab enhanced this TNF-α-stimulated expression. The presence of MHC Class I on HUVECs was decreased by VEGF and increased by TNF-α, respectively. Bevacizumab reversed VEGF downregulation and promoted TNF-α upregulation of MHC class I expression, suggesting that anti-VEGF treatment can boost the endothelial immunological reaction, a prerequisite for immune cell trafficking. Functionally, real-time monitoring of the proliferation of human PBMCs co-cultured on HUVEC monolayers over 3 days showed opposing effects on the proliferation of PBMCs between VEGF and TNF-α. Consistently, Bevacizumab antagonised VEGF suppression and sensitized TNF-α activation of PBMC growth over the time course. In line with these findings, Bevacizumab increased the surface expression of CD69 on VEGF-treated T cells collected from PBMCs after 3-day co-cultures with HUVECs. Furthermore, the proliferation of CD3+, CD8+ and CD4+ T cells was promoted via Bevacizumab. Collectively, this study demonstrates that targeting VEGF can enhance the immune response of ECs required for T cell recruitment. Our findings provide insights to a deeper understanding of increased vascular inflammatory response conferred by anti-VEGF treatment in addition to inhibiting angiogenesis, which supports its favourable dual role in the positive immunological synergism with immunotherapy. Full article

The brain actively obtains nutrients through various transporters on brain microvessel endothelial cells (BMECs). Major facilitator superfamily domain–containing protein 2a (MFSD2A) serves as a key transporter of docosahexaenoic acid (DHA) at the blood–brain barrier (BBB) and is exclusively expressed in BMECs. Although brain pericytes (PCs) regulate MFSD2A expression in BMECs, the underlying mechanism remains unclear. To determine whether PDGF-BB/PDGFRβ signaling between endothelial cells (ECs) and PCs affects MFSD2A protein expression and plasma membrane localization in ECs, we examined the impact of AG1296 (a PDGF receptor inhibitor) and Pdgfrb-knockdown PCs on a non-contact coculture BBB model comprising the primary cultures of rat brain ECs and PCs. The effects of PCs on MFSD2A expression, localization, and brain endothelial DHA uptake was assessed using Western blot, immunofluorescence staining, and [¹⁴C]DHA uptake by ECs, respectively. In ECs cocultured with PCs, MFSD2A expression and plasma membrane localization were significantly higher than in EC monolayers. Moreover, conditioned medium derived from PCs failed to enhance MFSD2A expression. The increased expression and membrane localization of MFSD2A were inhibited by AG1296 and Pdgfrb-knockdown PCs. Furthermore, PCs significantly increased [¹⁴C]DHA uptake by ECs. These findings suggest that PCs enhance MFSD2A expression and plasma membrane localization in ECs through PDGF-BB/PDGFRβ signaling. Full article

Magnesium alloy stents exhibit significant potential in the treatment of cardiovascular and cerebrovascular diseases due to their remarkable mechanical support and biodegradability. However, bare magnesium alloy stents often degrade too quickly and exhibit inadequate biocompatibility, which severely restricts their clinical applicability. Herein, a composite coating consisting of an MgF₂ conversion layer, a polydopamine (PDA) layer, fucoidan, and hyaluronic acid was prepared to enhance the corrosion resistance and biocompatibility of ZE21B alloy for a vascular stent application. The modified ZE21B alloy exhibited relatively high surface roughness, moderate wettability, and better corrosion resistance. Moreover, the modified ZE21B alloy with a low hemolysis rate and fibrinogen adsorption level confirmed improved hemocompatibility for medical requirements. Furthermore, the ZE21B alloy modified with fucoidan and hyaluronic acid enhanced the adhesion, proliferation, and NO release of endothelial cells (ECs). Simultaneously, it inhibits the adhesion and proliferation of smooth muscle cells (SMCs), promoting a competitive advantage for ECs over SMCs due to the synergistic effects of fucoidan and hyaluronic acid. The incorporation of fucoidan and hyaluronic acid markedly improved the corrosion resistance and biocompatibility of the ZE21B magnesium alloy. This development presents a straightforward and effective strategy for the advancement of biodegradable vascular stents. Full article

Brain endothelial cells (BECs) constitute the core component of the blood–brain barrier (BBB), regulating substance exchange between blood and the brain parenchyma to maintain central nervous system homeostasis. In pathological states, the BBB exhibits the disruption of tight junctions, endothelial cell (EC) damage, and increased permeability, accompanied by neuroinflammation, oxidative stress, and abnormal molecular signaling pathways, leading to neurotoxic effects in the brain parenchyma and exacerbating neurodegeneration and disease progression. This review systematically summarizes the developmental origin, structural characteristics, and pathological mechanisms of BECs in diseases such as Alzheimer’s disease, multiple sclerosis, stroke, and glioblastoma with a particular focus on the regulatory mechanisms of the Wnt/β-catenin and VEGF signaling pathways. By integrating the latest research advances, this review aims to provide a comprehensive perspective for understanding the role of BECs in physiological and pathological states and to provide a theoretical basis for the development of BBB-based therapeutic approaches for neurological diseases. Full article

Increased levels of reactive oxygen species (ROS) are a hallmark of cardiovascular disease. ROS impact the function of proteins largely through thiol modification leading to redox signalling. Acute, targeted interference with local ROS levels has been difficult. Therefore, how dynamics in redox signalling impact cardiovascular health is still a matter of current research. An inducible, endothelial cell-specific knock-in mouse model expressing a yeast D-amino acid oxidase enzyme was generated (Hipp11-Flox-Stop-Flox-yDAO-Cdh5-CreERT2^+/0 referred to as ecDAO). DAO releases H₂O₂ as a by-product of the conversion of D-amino acids into imino acids. The D-amino acid treatment of DAO-expressing cells therefore increases their intracellular H₂O₂ production. The induction of yDAO in the ecDAO mice was performed with tamoxifen. Subsequently, the mice received D-Alanine (D-Ala, 0.5 M) through drinking water, and the effects on ROS production and vascular and cardiac function were determined. ecDAO induction increased endothelial ROS production as well as ROS production in the lung, which is rich in endothelial cells. The functional consequences of this were, however limited: After minimally invasive myocardial infarction, there was no difference in the outcome between the control (CTL) and ecDAO mice. With respect to vascular function, three days of D-Ala slightly improved vascular function as demonstrated by an increase in the diameter of the carotid artery in vivo and decreased vessel constriction to phenylephrine. Fifty-two days of D-Ala induced cardiac remodelling, increased peripheral resistance, and overoxidation of peroxiredoxins. In conclusion, acute stimulation of endothelial ROS improves cardiovascular function, whereas prolonged ROS exposure deteriorates it. Full article