Lipid emulsion attenuates vasodilation by decreasing intracellular calcium and nitric oxide in vascular endothelial cells.

Lipid emulsion (LE), a widely used parenteral nutrition, exhibits a well-documented ability to reverse the vasodilatory effects induced by acetylcholine in blood vessels. However, the specific mechanisms underlying this action are not yet fully understood. This study aimed to elucidate the mechanism by which LE reverses vasodilation in vitro through dose-response curve experiments, calcium imaging, and fluorescence assays. The results revealed a significant attenuation of acetylcholine (Ach)-induced vasodilation in rat thoracic aortic rings following LE exposure. In human aortic endothelial cells, pretreatment with LE significantly suppressed ATP-induced calcium elevation. This suppression persisted even after elimination of extracellular calcium with a calcium chelator. Moreover, LE pre-exposure reduced the intracellular calcium concentration ([Ca2+]i) elevation in endothelial cells following cyclopiazonic acid (CPA) treatment, suggesting enhanced endoplasmic reticulum (ER) calcium reuptake. Additionally, nitric oxide (NO) fluorescence assays showed a decrease in NO production upon ATP stimulation post-LE pretreatment of endothelial cells. Taken together, these results indicate that the reversal of vasodilation by LE may involve enhanced ER calcium uptake, leading to a reduction in intracellular calcium concentration and suppression of NO (key vasodilatory agent) synthesis.

Immunomodulation by endothelial cells: prospects for cancer therapy.

Growing evidence highlights the importance of tumor endothelial cells (TECs) in the tumor microenvironment (TME) for promoting tumor growth and evading immune responses. Immunomodulatory endothelial cells (IMECs) represent a distinct plastic phenotype of ECs that exerts the ability to modulate immunity in health and disease. This review discusses our current understanding of IMECs in cancer biology, scrutinizing insights from single-cell reports to compare their characteristics and function dynamics across diverse tumor types, conditions, and species. We investigate possible implications of exploiting IMECs in the context of cancer treatment, particularly examining their influence on the efficacy of existing therapies and the potential to leverage them as targets in optimizing immunotherapeutic strategies.

Comprehensive assessment of corneal microstructural changes following V4c implantable collamer lens surgery using in vivo confocal microscopy.

BACKGROUND: Implantable Collamer Lense (ICL) presents a viable alternative to conventional refractive surgeries, but their impact on corneal microstructure remains unclear. By employing in vivo confocal microscopy (IVCM), we examined changes in stromal and endothelial cells following the insertion of V4c ICLs, with the goal of enhancing post-surgical care and outcomes. METHODS: In this longitudinal investigation, we conducted detailed preoperative assessments on 103 eyes from 53 participants. Follow-up evaluations were carried out after surgery at set intervals: one day, one week, one month, three months, six months, and twelve months. We used IVCM to analyze changes in stromal and endothelial cells. To assess differences between pre- and post-surgery variables and to investigate correlations with age, axial length (AL), and spherical equivalent refraction (SER), we applied a repeated measures mixed-effects model, with statistical significance set at P < 0.05. RESULTS: No vision-threatening complications were reported post-surgery. Significant reductions in stromal cell density (SCD) were observed postoperatively, with anterior and mid- SCD reaching their lowest values at 3 months and posterior SCD at 1 month, remaining below baseline at 12 months. endothelial cell density (ECD) and percentage of hexagonal cells (PHC) decreased initially, recovering by 12 months. Conversely, endothelial cellular area (ECA) and coefficient of variation of cell size (CoV) increased postoperatively, with the most significant change at 1 week. Endothelial deposits were detected in 49 of 101 eyes on postoperative day 1, half of them were absorbed within 3 months post-surgery. Changes in posterior SCD were negatively related to AL, while AL, SER, lens thickness showed associated with endothelium changes. CONCLUSION: Our findings elucidate the corneal microstructural changes following V4c ICL implantation, particularly the significant early reductions in stromal and endothelial cell densities. We recommend careful management of viscoelastics during surgery to minimize endothelial deposits that may harm the endothelium. Enhanced early postoperative monitoring and these surgical adjustments can lead to improved surgical and post-surgical care, ultimately supporting better patient recovery.

Decreased levels of L-selectin and platelet-endothelial cell adhesion molecule-1 in children with autism spectrum disorder.

OBJECTIVE: This study aimed to ascertain the serum levels of selectins (E, L, P) and platelet-endothelial adhesion molecule-1 (PECAM-1) in preschool children with autism spectrum disorder (ASD) and to establish a comparison with the levels observed in healthy controls. METHODS: The study included 34 children aged 2-7 years diagnosed with ASD (ASD group) and 34 randomly selected healthy children matched for age and sex to the ASD group. The children were free of any genetic or physical disease, clinically active infection, or medication use. The sociodemographic data form was completed by all parents. The Childhood Autism Rating Scale (CARS) and the Autism Behavior Checklist (ABC) were administered to the patient group, and the Aberrant Behavior Checklist (AbBC) was completed by the families of all children. Serum selectin (E, L, P) and PECAM-1 levels were measured using enzyme-linked immunosorbent assay (ELISA) kits. RESULTS: The results showed that the levels of both L-selectin (p = 0.007) and PECAM-1 (p = 0.019) were significantly lower in the ASD group than in the control group. No significant difference was observed between the groups concerning E-selectin and P-selectin levels (p > 0.05). It was observed that P-selectin variables were statistically significant in predicting the presence of ASD (p = 0.019). A remarkable inverse correlation was found between the AbBC irritability subscale score and L-selectin (r = -0.296, p = 0.014) and PECAM-1 (r = -0.276, p = 0. 023); the AbBC Lethargy-Social Withdrawal subscale score and E-Selectin (r = -0.239, p = 0.049), L-Selectin (r = -0.297, p = 0.014) and PECAM-1 (r = -0.264, p = 0.029); L-Selectin levels and the AbBC stereotypic behavior subscale (r = -0.248, p = 0.042). No statistically significant relationship was observed between selectins (E, L, P) and PECAM-1 levels and CARS scale, ABC subscale or total scores and age variables (p > 0.05). CONCLUSIONS: These study results suggest that L-selectin, P-selectin and PECAM-1 may play a role in the pathophysiology of ASD.

Unveiling the association between fluoroquinolones and aortic diseases using real-world database analysis and pharmacological experiments.

Fluoroquinolones, which are widely used antibiotics, have been linked to aortic disease, which prompted an FDA warning in 2018. Recent reports have challenged the perception that fluoroquinolones pose a significant risk for vascular diseases. This study aimed to investigate whether fluoroquinolones increase the risk of aortic diseases by focusing on the onset of aortic dissection. Levofloxacin (LVFX), a fluoroquinolone, was studied in vitro using cultured vascular cells and in vivo using a mouse model prone to aortic dissection. Risk of adverse drug events was analyzed using VigiBase, a global safety database, and a retrospective cohort analysis was conducted using the JMDC Claims database. LVFX resulted in endothelial cell injury and increased matrix metalloproteinases in vitro. However, in vivo studies showed no significant effect on elastin degradation or aortic dissection incidence. The effect of LVFX on endothelial injury was altered during the onset of dissection, exacerbating injury before onset but inhibiting it afterward. Safety database analysis showed no significant risk signals for aortic dissection associated with fluoroquinolones, which was supported by findings in the receipt database. Inconsistencies were observed in the in vitro and in vivo actions of fluoroquinolones and differences in their effects on aortic dissection and aneurysms. Despite cytotoxicity, the risk of aortic dissection was not significantly increased in clinical scenarios. Based on our findings, concerns regarding aortic diseases do not justify discontinuation of fluoroquinolone use. Further studies are needed to elucidate the conflicting actions of fluoroquinolones, taking into account background pathophysiology such as infection and inflammation.

Role of naringin in the treatment of atherosclerosis.

Atherosclerosis (AS) is a major pathological basis of coronary heart disease. However, the currently available medications are unable to effectively reduce the incidence of cardiovascular events in the majority of patients with AS. Therefore, naringin has been attracting considerable attention owing to its anti-AS effects. Naringin can inhibit the growth, proliferation, invasion, and migration of vascular smooth muscle cells, ameliorate endothelial cell inflammation and apoptosis, lower blood pressure, halt the cell cycle at the G1 phase, and impede growth via its antioxidant and free radical scavenging effects. These activities suggest the potential anti-AS effects of naringin. In this review article, we comprehensively summarized the latest findings on the anti-AS effects of naringin and their underlying mechanisms, providing a crucial reference for future research on the anti-AS potential of this agent.

MCT1-mediated endothelial cell lactate shuttle as a target for promoting axon regeneration after spinal cord injury.

Rationale: Spinal cord injury (SCI)-induced vascular damage causes ischemia and hypoxia at the injury site, which, in turn, leads to profound metabolic disruptions. The effects of these metabolic alterations on neural tissue remodeling and functional recovery have yet to be elucidated. The current study aimed to investigate the consequences of the SCI-induced hypoxic environment at the epicenter of the injury. Methods: This study employed metabolomics to assess changes in energy metabolism after SCI. The use of a lactate sensor identified lactate shuttle between endothelial cells (ECs) and neurons. Reanalysis of single-cell RNA sequencing data demonstrated reduced MCT1 expression in ECs after SCI. Additionally, an adeno-associated virus (AAV) overexpressing MCT1 was utilized to elucidate its role in endothelial-neuronal interactions, tissue repair, and functional recovery. Results: The findings revealed markedly decreased monocarboxylate transporter 1 (MCT1) expression that facilitates lactate delivery to neurons to support their energy metabolism in ECs post-SCI. This decreased expression of MCT1 disrupts lactate transport to neurons, resulting in a metabolic imbalance that impedes axonal regeneration. Strikingly, our results suggested that administering adeno-associated virus specifically to ECs to restore MCT1 expression enhances axonal regeneration and improves functional recovery in SCI mice. These findings indicate a novel link between lactate shuttling from endothelial cells to neurons following SCI and subsequent neural functional recovery. Conclusion: In summary, the current study highlights a novel metabolic pathway for therapeutic interventions in the treatment of SCI. Additionally, our findings indicate the potential benefits of targeting lactate transport mechanisms in recovery from SCI.

Constitutive DAMPs in CNS injury: From preclinical insights to clinical perspectives.

Damage-associated molecular patterns (DAMPs) are endogenous molecules released in tissues upon cellular damage and necrosis, acting to initiate sterile inflammation. Constitutive DAMPs (cDAMPs) have the particularity to be present within the intracellular compartments of healthy cells, where they exert diverse functions such as regulation of gene expression and cellular homeostasis. However, after injury to the central nervous system (CNS), cDAMPs are rapidly released by stressed, damaged or dying neuronal, glial and endothelial cells, and can trigger inflammation without undergoing structural modifications. Several cDAMPs have been described in the injured CNS, such as interleukin (IL)-1α, IL-33, nucleotides (e.g. ATP), and high-mobility group box protein 1. Once in the extracellular milieu, these molecules are recognized by the remaining surviving cells through specific DAMP-sensing receptors, thereby inducing a cascade of molecular events leading to the production and release of proinflammatory cytokines and chemokines, as well as cell adhesion molecules. The ensuing immune response is necessary to eliminate cellular debris caused by the injury, allowing for damage containment. However, seeing as some molecules associated with the inflammatory response are toxic to surviving resident CNS cells, secondary damage occurs, aggravating injury and exacerbating neurological and behavioral deficits. Thus, a better understanding of these cDAMPs, as well as their receptors and downstream signaling pathways, could lead to identification of novel therapeutic targets for treating CNS injuries such as SCI, TBI, and stroke. In this review, we summarize the recent literature on cDAMPs, their specific functions, and the therapeutic potential of interfering with cDAMPs or their signaling pathways.

Pericyte-to-Endothelial Cell Communication via Tunneling Nanotubes Is Disrupted by a Diol of Docosahexaenoic Acid.

The pericyte coverage of microvessels is altered in metabolic diseases, but the mechanisms regulating pericyte-endothelial cell communication remain unclear. This study investigated the formation and function of pericyte tunneling nanotubes (TNTs) and their impact on endothelial cell metabolism. TNTs were analyzed in vitro in retinas and co-cultures of pericytes and endothelial cells. Using mass spectrometry, the influence of pericytes on endothelial cell metabolism was examined. TNTs were present in the murine retina, and although diabetes was associated with a decrease in pericyte coverage, TNTs were longer. In vitro, pericytes formed TNTs in the presence of PDGF, extending toward endothelial cells and facilitating mitochondrial transport from pericytes to endothelial cells. In experiments with mitochondria-depleted endothelial cells displaying defective TCA cycle metabolism, pericytes restored the mitochondrial network and metabolism. 19,20-Dihydroxydocosapentaenoic acid (19,20-DHDP), known to disrupt pericyte-endothelial cell junctions, prevented TNT formation and metabolic rescue in mitochondria-depleted endothelial cells. 19,20-DHDP also caused significant changes in the protein composition of pericyte-endothelial cell junctions and involved pathways related to phosphatidylinositol 3-kinase, PDGF receptor, and RhoA signaling. Pericyte TNTs contact endothelial cells and support mitochondrial transfer, influencing metabolism. This protective mechanism is disrupted by 19,20-DHDP, a fatty acid mediator linked to diabetic retinopathy.

Intracellular bactericidal activity and action mechanism of MDP1 antimicrobial peptide against VRSA and MRSA in human endothelial cells.

Introduction: Staphylococcus aureus is a prominent cause of postoperative infections, often persisting within host cells, leading to chronic infections. Conventional antibiotics struggle to eliminate intracellular S. aureus due to poor cell penetration. Antimicrobial peptides are a new hope for tackling intracellular bacteria. Accordingly, this study examines the antimicrobial peptide MDP1, derived from melittin, for its efficacy against intracellular S. aureus. Methods: In this study, the physiochemical properties (Prediction of three-dimensional structure, circular dichroism and helical wheel projection analysis) were investigated. Extracellular antibacterial activity and cytotoxicity of MDP1 were also assessed. The mechanism of interaction of MDP1 with S. aureus was evaluated by molecular dynamic simulation, atomic force and confocal microscopy. Bacterial internalization into an endothelial cell model was confirmed through culture and transmission electron microscopy. The effect of the peptide on intracellular bacteria was investigated by culture and epi-fluorescence microscopy. Results and discussion: 3D structural prediction proved the conformation of MDP1 as an α-helix peptide. Helical-wheel projection analysis indicated the proper orientation of hydrophobic amino acid residues for membrane interaction. CD spectroscopy of MDP1 showed that MDP1 in SDS 10 and 30 mM adopted 87 and 91% helical conformation. Atomic force and confocal microscopy assessments as well as molecular dynamics studies revealed the peptide-bacterial membrane interaction. MDP1, at the concentration of 0.32 µg mL-1, demonstrated a fold reduction of 21.7 ± 1.8, 1.7 ± 0.2, and 7.3 ± 0.8 in intracellular bacterial load for ATCC, VRSA, and MRSA, respectively. Molecular dynamics results demonstrate a preferential interaction of MDP1 with POPG/POPE membranes, primarily driven by electrostatic forces and hydrogen bonding. In POPC systems, two out of four MDP1 interacted effectively, while all four MDP1 engaged with POPG/POPE membranes. Gathering all data together, MDP1 is efficacious in the reduction of intracellular VRSA and MRSA proved by culture and epi-fluorescent microscopy although further studies should be performed to increase the intracellular activity of MDP1.

Establishment and long-term expansion of adult hepatobiliary organoids co-cultured with liver endothelial cells.

The liver has a unique ability to regenerate in response to injury or disease with hepatocytes and biliary epithelial cells (BECs) driving the regenerative response. Liver progenitor cells (LPCs) also play role in regeneration with the ability to differentiate into either hepatocytes or BECs. However, during chronic liver disease, the regenerative capacity of the liver is impaired. The use of LPCs is a promising therapeutic strategy for patients with chronic liver diseases. LPCs can be expanded in vitro as self-renewing organoids, however, most approaches to LPC organoids do not include critical cells from the LPC niche in 3D organoid cultures. In this study, we highlight the role of liver endothelial cells (LiECs), as a part of LPC niche, in supporting the hepatobiliary organoids in long-term culture even in the absence of defined growth supplements, such as Wnt agonists. Furthermore, LiECs alter the gene expression profile of hepatobiliary organoids involved in inflammation, migration, extracellular matrix organization, and receptor signaling pathway through paracrine manner. Our findings expand the role of LiECs for regulating stemness of LPCs and elucidate a role for niche cells in a LPC organoid co-culture model with a reduction in growth supplements.

The effect of adrenaline and trypan blue used during cataract surgery on anatomical and functional outcomes in pseudoexfoliation syndrome patients.

PURPOSE: To evaluate the effect of the intracameral adrenaline and trypan blue used during cataract surgery on corneal endothelial parameters in pseudoexfoliation syndrome (PEX) patients. METHODS: The patients were divided into four groups according to intraoperative use of agents during cataract surgery: intracameral adrenaline (1/10,000, 0.1 ml) (group 1), trypan blue (0.6 mg/ml, 0.1 ml) (group 2), combination of adrenaline and trypan blue (group 3) and none (group 4). RESULTS: Preoperative ECD, CV, HEX and CCT parameters were similar between the groups. A mean loss of 12.7% in ECD was observed at the postoperative third months compared to the preoperative. In group 3, ECD was found to be lower in the postoperative third months compared to the preoperative (p = 0.014). In the other groups, no statistically significant difference was found in preoperative and postoperative comparisons. CONCLUSION: In conclusion, the utilization of intracameral adrenaline or trypan blue did not cause a significant difference in corneal endothelium in PEX patients. However, their combined use may have a negative effect on endothelial cell density. In a cataract surgery performed in the presence of PEX, the increased likelihood of endothelial damage should be taken into consideration, and appropriate precautions should be taken preoperatively and intraoperatively.

Expression of mRNA for molecules that regulate angiogenesis, endothelial cell survival, and vascular permeability is altered in endothelial cells isolated from db/db mouse hearts.

Metabolic syndrome (MetS) is a condition that includes symptoms, such as obesity, hyperglycemia, and hypertension, which elevate cardiovascular risk. An impaired angiogenic response of endothelial cells (ECs) in heart and peripheral organs has been proposed in MetS, but the mechanisms of this phenomenon have not been thoroughly explored. Results obtained from evaluating the whole myocardium are inconsistent, since different types of cells react differently to MetS environment and a variety of molecular pathways are involved in the angiogenic response. Therefore, the aim of this paper was to study one selected pathway-the VEGF/VEGFR pathway, which regulates the angiogenic response and microvascular permeability in ECs isolated from db/db mouse hearts. The expression of mRNAs for VEGF/VEGFR axis proteins was assessed with RT-PCR in ECs isolated from control and db/db mouse myocardium. The density of CD31-, VEGFR2-, and VE-cadherin-positive cells was examined with confocal microscopy, and the ultrastructure of ECs was analyzed with transmission electron microscopy. The aortic ring assay was used to assess the capacity of ECs to respond to angiogenic stimuli. Our results showed a decreased number of microvessels, diminished expression of VE-cadherin and VEGFR2 and widened gaps between the ECs of microcapillaries. The aortic ring assay showed a diminished number of sprouts in db/db mice. These results may indicate that ECs in MetS enhance the production of mRNA for VEGF/VRGFR axis proteins, yet sprout formation and vascular barrier maintenance are limited. These novel data may provide a foundation for further studies on ECs dysfunction in MetS.

Impaired microvascular function in patients with sickle cell anemia and leg ulcers improved with healing.

Leg Ulcer (LU) pathophysiology is still not well understood in sickle cell anaemia (SCA). We hypothesised that SCA patients with LU would be characterised by lower microvascular reactivity. The aim of the present study was to compare the microcirculatory function (transcutaneous oxygen pressure (TcPO2) on the foot and laser Doppler flowmetry on the arm) and several blood biological parameters between nine SCA patients with active LU (LU+) and 56 SCA patients with no positive history of LU (LU-). We also tested the effects of plasma from LU+ and LU- patients on endothelial cell activation. We observed a reduction of the TcPO2 in LU+ compared to LU- patients. In addition, LU+ patients exhibited lower cutaneous microvascular vasodilatory capacity in response to acetylcholine, current and local heating compared to LU- patients. Inflammation and endothelial cell activation in response to plasma did not differ between the two groups. Among the nine patients from the LU+ group, eight were followed and six achieved healing in 4.4 ± 2.5 months. Among thus achieving healing, microvascular vasodilatory capacity in response to acetylcholine, current and local heating and TcPO2 improved after healing. In conclusion, microcirculatory function is impaired in patients with LU, and improves with healing.

Characterization of the angiomodulatory effects of Interleukin 11 cis- and trans-signaling in the retina.

BACKGROUND: The IL-6 cytokine family, with its crucial and pleiotropic intracellular signaling pathway STAT3, is a promising target for treating vasoproliferative retinal diseases. Previous research has shown that IL-6 cis-signaling (via membrane-bound receptors) and trans-signaling (via soluble receptors) can have distinct effects on target cells, leading to their application in various disease treatments. While IL-6 has been extensively studied, less is known about the angiogenic effects of IL-11, another member of the IL-6 family, in the retina. Therefore, the aim of this study was to characterize the effects of IL-11 on retinal angiogenesis. MAIN TEXT: In vitreous samples from proliferative diabetic retinopathy (PDR) patients, elevated levels of IL-11Rα, but not IL-11, were detected. In vitro studies using vascular endothelial cells revealed distinct effects of cis- and trans-signaling: cis-signaling (IL-11 alone) had antiangiogenic effects, while trans-signaling (IL-11 + sIL-11Rα) had proangiogenic and pro-migratory effects. These differences can be attributed to their individual signaling responses and associated transcriptomic changes. Notably, no differences in cis- and trans-signaling were detected in primary mouse Müller cell cultures. STAT3 and STAT1 siRNA knockdown experiments revealed opposing effects on IL-11 signaling, with STAT3 functioning as an antiproliferative and proapoptotic player while STAT1 acts in opposition to STAT3. In vivo, both IL-11 and IL-11 + sIL-11Rα led to a reduction in retinal neovascularization. Immunohistochemical staining revealed Müller cell activation in response to treatment, suggesting that IL-11 affects multiple retinal cell types in vivo beyond vascular endothelial cells. CONCLUSIONS: Cis- and trans-signaling by IL-11 have contrasting angiomodulatory effects on endothelial cells in vitro. In vivo, cis- and trans-signaling also influence Müller cells, ultimately determining the overall angiomodulatory impact on the retina, highlighting the intricate interplay between vascular and glial cells in the retina.

Role of CD44-Positive Extracellular Vesicles Derived from Highly Metastatic Mouse Mammary Carcinoma Cells in Pre-Metastatic Niche Formation.

Malignant breast cancers pose a notable challenge when it comes to treatment options. Recently, research has implicated extracellular vesicles (EVs) secreted by cancer cells in the formation of a pre-metastatic niche. Small clumps of CD44-positive breast cancer cells are efficiently transferred through CD44-CD44 protein homophilic interaction. This study aims to examine the function of CD44-positive EVs in pre-metastatic niche formation in vitro and to suggest a more efficacious EV formulation. We used mouse mammary carcinoma cells, BJMC3879 Luc2 (Luc2 cells) as the source of CD44-positive EVs and mouse endothelial cells (UV2 cells) as the recipient cells in the niche. Luc2 cells exhibited an enhanced secretion of EVs expressing CD44 and endothelial growth factors (VEGF-A, -C) under 20% O2 (representative of the early stage of tumorigenesis) compared to its expression under 1% O2 (in solid tumor), indicating that pre-metastatic niche formation occurs in the early stage. Furthermore, UV2 endothelial cells expressing CD44 demonstrated a high level of engulfment of EVs that had been supplemented with hyaluronan, and the proliferation of UV2 cells occurred following the engulfment of EVs. These results suggest that anti-VEGF-A and -C encapsulated, CD44-expressing, and hyaluronan-coated EVs are more effective for tumor metastasis.

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OBJECTIVES: To study the effects and mechanisms of tetramethylpyrazine (TMP) on tumor necrosis factor-α (TNF-α)-induced inflammatory injury in human coronary artery endothelial cells (HCAEC). METHODS: HCAEC were randomly divided into four groups: the control group (no treatment), the model group (treated with TNF-α, 50 ng/mL for 24 hours), the TMP group (pre-treated with TMP, 80 µg/mL for 12 hours followed by TNF-α treatment for 24 hours), and the SIRT1 inhibitor group (pre-treated with TMP and the specific SIRT1 inhibitor EX527 for 12 hours followed by TNF-α treatment for 24 hours). Cell viability was assessed using the CCK-8 method, lactate dehydrogenase (LDH) activity was measured using an LDH assay kit, reactive oxygen species (ROS) levels were observed using DCFH-DA staining, expression of pyroptosis-related proteins was detected by Western blot, and SIRT1 expression was analyzed using immunofluorescence staining. RESULTS: Compared to the control group, the model group showed decreased cell viability, increased LDH activity, ROS level and expression of pyroptosis-related proteins, and decreased SIRT1 expression (P<0.05). Compared to the model group, the TMP group exhibited increased cell viability, decreased LDH activity, ROS level and expression of pyroptosis-related proteins, and increased SIRT1 expression (P<0.05). In comparison to the TMP group, the SIRT1 inhibitor group showed decreased cell viability, increased LDH activity, ROS level and expression of pyroptosis-related proteins, and decreased SIRT1 expression (P<0.05). CONCLUSIONS: TMP may attenuate TNF-α-induced inflammatory injury in HCAEC, which is associated with the inhibition of pyroptosis and activation of the SIRT1 signaling pathway.

MEK inhibitor PD0325901 upregulates CD34 expression in endothelial cells via inhibition of ERK phosphorylation.

Introduction: CD34-positive endothelial progenitor cells (EPCs) promote angiogenesis and are a promising tool for regenerative cell therapy of ischemic diseases. However, the number and quality of CD34-positive cells decrease owing to various external and internal factors; thus, an efficient method is needed to establish CD34-positive EPCs. The generation of functional cells by reprogramming, that is, manipulating cell fate via gene transfer and/or treatment with chemical compounds, has recently been reported. Therefore, we aimed to generate CD34-positive cells by the reprogramming of endothelial cells (ECs). Methods: Based on previous reports, seven candidate chemical compounds were selected to reprogram human umbilical vein ECs (HUVECs) to CD34-positive cells. Following stimulation with the chemical compounds, the expression of CD34 was evaluated using quantitative PCR, flow cytometry, and immunocytochemistry. Results: HUVECs treated with the compounds exhibited increased CD34 expression. We cultured cells in alternate media lacking one of the seven compounds and found no CD34 expression in cells treated with PD0325901-free media, suggesting that PD0325901-a MEK inhibitor-mainly contributed to the increase in CD34 expression. We found that 98% of cells were CD34-positive after PD0325901 treatment alone for 7 d. Western blotting revealed that the phosphorylation of ERK was suppressed in PD0325901-treated cells. No upregulation of CD34 was observed in fibroblast cell lines, even after PD0325901 treatment. These results suggested that PD0325901 induces CD34-positive cells by inhibiting ERK phosphorylation in ECs. Conclusions: CD34 expression was strongly induced in ECs by treatment with the MEK inhibitor PD0325901 in vitro. Our study provides a useful reference for the establishment of CD34-positive EPCs and will contribute to the development of regenerative therapies, especially for ischemic diseases.

Advances in pathogenesis and treatment of vascular endothelial injury-related diseases mediated by mitochondrial abnormality.

Vascular endothelial cells, serving as a barrier between blood and the arterial wall, play a crucial role in the early stages of the development of atherosclerosis, cardiovascular diseases (CVDs), and Alzheimer's disease (AD). Mitochondria, known as the powerhouses of the cell, are not only involved in energy production but also regulate key biological processes in vascular endothelial cells, including redox signaling, cellular aging, calcium homeostasis, angiogenesis, apoptosis, and inflammatory responses. The mitochondrial quality control (MQC) system is essential for maintaining mitochondrial homeostasis. Current research indicates that mitochondrial dysfunction is a significant driver of endothelial injury and CVDs. This article provides a comprehensive overview of the causes of endothelial injury in CVDs, ischemic stroke in cerebrovascular diseases, and AD, elucidating the roles and mechanisms of mitochondria in these conditions, and aims to develop more effective therapeutic strategies. Additionally, the article offers treatment strategies for cardiovascular and cerebrovascular diseases, including the use of clinical drugs, antioxidants, stem cell therapy, and specific polyphenols, providing new insights and methods for the clinical diagnosis and treatment of related vascular injuries to improve patient prognosis and quality of life. Future research should delve deeper into the molecular and mechanistic links between mitochondrial abnormalities and endothelial injury, and explore how to regulate mitochondrial function to prevent and treat CVDs.