Endothelial Cell Inflammation Research Articles

Layer-by-layer assembly of quercetin-loaded zein/γPGA/low-molecular-weight chitosan/fucoidan nanosystem for targeting inflamed blood vessels

Chitosan acts as a versatile carrier in polymeric nanoparticle (NP) for diverse drug administration routes. Delivery of antioxidants, such as quercetin (Qu) showcases potent antioxidant and anti-inflammatory properties for reduction of various cardiovascular diseases, but low water solubility limits uptake. To address this, we developed a novel layer-by-layer zein/gamma-polyglutamic acid (γPGA)/low-molecular-weight chitosan (LC)/fucoidan NP for encapsulating Qu and targeting inflamed vessel endothelial cells. We used zein (Z) and γPGA (r) to encapsulate Qu (Qu-Zr NP) exhibited notably higher encapsulation efficiency compared to zein alone. Qu-Zr NP coated with LC (Qu-ZrLC2 NP) shows a lower particle size (193.2 ± 2.9 nm), and a higher zeta potential value (35.2 ± 0.4 mV) by zeta potential and transmission electron microscopy analysis. After coating Qu-ZrLC2 NP with fucoidan, Qu-ZrLC2Fa NP presented particle size (225.16 ± 0.92 nm), zeta potential (−25.66 ± 0.51 mV) and maintained antioxidant activity. Further analysis revealed that Qu-ZrLC2Fa NP were targeted and taken up by HUVEC cells and EA.hy926 endothelial cells. Notably, we observed Qu-ZrLC2Fa NP targeting zebrafish vessels and isoproterenol-induced inflamed vessels of rat. Our layer-by-layer formulated zein/γPGA/LC/fucoidan NP show promise as a targeted delivery system for water-insoluble drugs. Qu-ZrLC2Fa NP exhibit potential as an anti-inflammatory therapeutic for blood vessels.

LncRNA MALAT1 suppresses monocyte-endothelial cell interactions by targeting miR-30b-5p and enhancing ATG5-mediated autophagy

BackgroundMonocyte-endothelial cell (EC) interactions are one of the earliest events in the development of atherosclerosis and play a crucial role in atherosclerotic plaque formation. Although attempts have been made to modulate this interaction, the underlying molecular signalling mechanisms remain unclear. This study aimed to investigate the role of long non-coding RNA MALAT1 in monocyte-EC interactions. MethodsThe expression of MALAT1, ICAM-1, VCAM-1, P-selectin, CCL2 and CXCL1 was evaluated in ApoE-/- mouse aortic tissues and inflamed human umbilical vein endothelial cells (HUVECs). The regulatory impact of MALAT1 on cell adhesion molecules, monocyte-EC adhesion, and autophagy was assessed. The interactions between MALAT1 and microRNAs (miRNAs) were evaluated using dual-luciferase reporter and RNA pull-down assays. ResultsMALAT1 expression decreased in ApoE-/- mouse aortic tissues and inflammatory HUVECs. MALAT1 overexpression suppressed the expression of ICAM-1, VCAM-1 and CXCL1, and reduced the migration and adhesion of monocytes to ECs. Inhibition of MALAT1 promoted cell adhesion molecule expression and monocyte-EC interactions. Mechanistically, MALAT1 binds directly to miR-30b-5p and decreases its effective expression by functioning as an endogenous sponge, thereby increasing the expression of autophagy-related gene 5 (ATG5) and stimulates endothelial autophagy. ConclusionsOur findings suggest that MALAT1 suppresses monocyte-EC interactions by targeting miR-30b-5p and enhancing ATG5-mediated endothelial autophagy. These data imply that MALAT1 may play a protective role at the early stages of the atherosclerotic process.

Current and Future Treatment Options for Cerebral Cavernous Malformations

Cerebral cavernous malformations (CCMs) are vascular lesions associated with seizures, hemorrhage, and neurologic deficits. The familial form of CCM constitutes ≈20% of cases and presents with multifocal lesions in the brain and spinal cord, whereas the more common sporadic form typically involves a single lesion. Treatments of CCM include surgical resection and stereotactic radiosurgery, as well as management of symptoms (eg, seizures). Surgical resection or irradiation of lesions in eloquent areas requires careful consideration because of the potential for morbidity and mortality, and these treatments are not advised for asymptomatic lesions. The purpose of this narrative review is to describe the current state of treatments for CCM, with an emphasis on potential clinically relevant pharmacologic treatments aimed at targeting aberrant molecular signaling associated with CCM. Literature was identified through PubMed using search terms related to treatments of CCMs. In endothelial cells, overactivation of RhoA/Rho‐associated kinase contributes to disruption of cell‐cell junctions and a shift to a senescence‐associated secretory phenotype, which leads to inflammation, migration, and invasiveness of mutant endothelial cells. Specific (NRL‐1049) and nonspecific (fasudil, statins) inhibition of Rho‐associated kinase has shown effectiveness to reduce lesion burden in mouse models of CCM. A phase 1/2 clinical trial is currently underway to investigate the efficacy of atorvastatin in patients with CCM, and a first‐in‐human clinical trial to evaluate safety, tolerability, and pharmacokinetic parameters of NRL‐1049 began in 2023. The β‐blocker propranolol and the superoxide dismutase mimetic REC‐994 have also shown effectiveness in attenuating lesion burden in preclinical studies. Results from a pilot phase 2 clinical trial of propranolol support further investigation in an adequately powered trial, and the safety, pharmacokinetics, and potential efficacy of REC‐994 are currently being evaluated in a phase 2 clinical trial. Additional agents have been used solely in preclinical models and require clinical evaluation.

Anti-inflammatory mechanisms of neutrophil membrane-coated nanoparticles without drug loading

Neutrophil membrane-coated nanoparticles (NM-NPs) are nanomedicines with traits of mimicking the surface properties and functions of neutrophils, which are the most abundant type of white blood cells in the human body. NM-NPs have been widely used as targeted drug delivery systems for various inflammatory diseases, but their intrinsic effects on inflammation are not fully characterized yet. This study found that NM-NPs could modulate inflammation by multiple mechanisms without drug loading. NM-NPs could inhibit the recruitment of neutrophils and macrophages to the inflamed site by capturing chemokines and blocking their adhesion to inflamed endothelial cells. After internalized by macrophages and other phagocytic cells, NM-NPs could alter their phenotype by phosphatidylserine and simultaneously degrade the sequestered and neutralized cytokines and chemokines by lysosomal degradation. Under these effects, NM-NPs exhibited significant anti-inflammatory effects on LPS-induced inflammatory liver injury in vivo without drug loading. Our study unveiled the anti-inflammatory effects and mechanisms of NM-NPs without drug loading, and provided new insights and evidence for understanding their biological effects and safety, as well as developing more effective and safe targeted drug delivery systems.

Saponins from Allium macrostemon Bulbs Attenuate Endothelial Inflammation and Acute Lung Injury via the NF-κB/VCAM-1 Pathway.

Endothelial inflammation is a multifaceted physiological process that plays a pivotal role in the pathogenesis and progression of diverse diseases, encompassing but not limited to acute lung infections like COVID-19, coronary artery disease, stroke, sepsis, metabolic syndrome, certain malignancies, and even psychiatric disorders such as depression. This inflammatory response is characterized by augmented expression of adhesion molecules and secretion of pro-inflammatory cytokines. In this study, we discovered that saponins from Allium macrostemon bulbs (SAMB) effectively inhibited inflammation in human umbilical vein endothelial cells induced by the exogenous inflammatory mediator lipopolysaccharide or the endogenous inflammatory mediator tumor necrosis factor-α, as evidenced by a significant reduction in the expression of pro-inflammatory factors and vascular cell adhesion molecule-1 (VCAM-1) with decreased monocyte adhesion. By employing the NF-κB inhibitor BAY-117082, we demonstrated that the inhibitory effect of SAMB on VCAM-1 expression may be attributed to the NF-κB pathway's inactivation, as characterized by the suppressed IκBα degradation and NF-κB p65 phosphorylation. Subsequently, we employed a murine model of lipopolysaccharide-induced septic acute lung injury to substantiate the potential of SAMB in ameliorating endothelial inflammation and acute lung injury in vivo. These findings provide novel insight into potential preventive and therapeutic strategies for the clinical management of diseases associated with endothelial inflammation.

Mast cell degranulation-triggered by SARS-CoV-2 induces tracheal-bronchial epithelial inflammation and injury

SARS-CoV-2 infection-induced hyper-inflammation is a key pathogenic factor of COVID-19. Our research, along with others', has demonstrated that mast cells (MCs) play a vital role in the initiation of hyper-inflammation caused by SARS-CoV-2. In previous study, we observed that SARS-CoV-2 infection induced the accumulation of MCs in the peri-bronchus and bronchioalveolar-duct junction in humanized mice. Additionally, we found that MC degranulation triggered by the spike protein resulted in inflammation in alveolar epithelial cells and capillary endothelial cells, leading to subsequent lung injury. The trachea and bronchus are the routes for SARS-CoV-2 transmission after virus inhalation, and inflammation in these regions could promote viral spread. MCs are widely distributed throughout the respiratory tract. Thus, in this study, we investigated the role of MCs and their degranulation in the development of inflammation in tracheal-bronchial epithelium. Histological analyses showed the accumulation and degranulation of MCs in the peri-trachea of humanized mice infected with SARS-CoV-2. MC degranulation caused lesions in trachea, and the formation of papillary hyperplasia was observed. Through transcriptome analysis in bronchial epithelial cells, we found that MC degranulation significantly altered multiple cellular signaling, particularly, leading to upregulated immune responses and inflammation. The administration of ebastine or loratadine effectively suppressed the induction of inflammatory factors in bronchial epithelial cells and alleviated tracheal injury in mice. Taken together, our findings confirm the essential role of MC degranulation in SARS-CoV-2-induced hyper-inflammation and the subsequent tissue lesions. Furthermore, our results support the use of ebastine or loratadine to inhibit SARS-CoV-2-triggered degranulation, thereby preventing tissue damage caused by hyper-inflammation.

SirT7-mediated transcription of fascin in hyperglycemic glomerular endothelial cells contributes to EndMT in diabetic nephropathy.

Diabetic nephropathy (DN) is the main cause of end-stage renal disease worldwide. It is reported that the endothelial-to-mesenchymal transition (EndMT) in glomerular endothelial cells plays an important role in DN. As a specific form of epithelial-to-mesenchymal transition, EndMT may involve common regulators of epithelial-to-mesenchymal transition. Fascin has been shown to mediate epithelial-to-mesenchymal transition. In addition, SirT7 has been confir med to contribute to inflammation in hyperglycemic endothelial cells via the modulation of gene transcription. In this study, we speculate that SirT7 modulates fascin transcription and is thus involved in EndMT in hyperglycemic glomerular endothelial cells. Our data indicate that α-smooth muscle actin (α-SMA) and fascin levels are increased, while CD31 levels are decreased in the kidneys of DN rats. Consistently, our cellular experiments reveal that high glucose treatment elevates fascin levels and induces EndMT in human glomerular endothelial cells (HGECs). Moreover, silencing of fascin inhibits EndMT in hyperglycaemic HGECs. In addition, SirT7 is found to be decreased in hyperglycemic cells and in the kidneys of DN mice. Moreover, the inhibition of SirT7 increases fascin level and mediates EndMT. An increase in SirtT7 expression decreases fascin expression, inhibits EndMT, and improves renal function in hyperglycemic cells and DN mice. SirT7 is found to bind to the promoter region of fascin. In summary, the present study indicates that SirT7 transcribes fascin to contribute to hyperglycemia-induced EndMT in DN patients.

Bone mesenchymal stem cell-derived exosomal miR-26a-3p promotes autophagy to attenuate LPS-induced apoptosis and inflammation in pulmonary microvascular endothelial cells.

Acute lung injury (ALI) is a serious lung disease. The apoptosis and inflammation of pulmonary microvascular endothelial cells (PMVECs) are the primary reasons for ALI. This study aimed to explore the treatment effect and regulatory mechanism of bone mesenchymal stem cell-derived exosomes (BMSC-expos) on ALI. PMVECs were stimulated by Lipopolysaccharide (LPS) to imitate ALI environment. Cell viability was determined by CCK-8 assay. Cell apoptosis was evaluated by TUNEL and flow cytometry. ELISA was utilized for testing the contents of TNF-α, IL-1β, IL-6, and IL-17. Western blot was applied for testing the levels of autophagy-related proteins LC3, p62, and Beclin-1. RNA interaction was determined by luciferase reporter assay. The ALI rat model was established by intratracheal injection of LPS. Evans blue staining was utilized for detecting pulmonary vascular permeability. Our results showed that LPS stimulation notably reduced cell viability, increased cell apoptosis rate, and enhanced the contents of inflammatory factors in PMVECs. However, BMSC-exo treatment significantly abolished the promoting effects of LPS on cell injury. In addition, we discovered that BMSC-exo treatment notably activated autophagy in LPS-induced PMVECs. Furthermore, BMSC-expos upregulated miR-26a-3p expression and downregulated PTEN in PMVECs. MiR-26a-3p was directly bound to PTEN. MiR-26a-3p overexpression reduced cell apoptosis, and inflammation and promoted autophagy by silencing PTEN. Animal experiments proved that miR-26a-3p overexpression effectively improved LPS-induced lung injury in rats. The results proved that BMSC-expos promotes autophagy to attenuate LPS-induced apoptosis and inflammation in pulmonary microvascular endothelial cells via miR-26a-3p/PTEN axis.

Abnormal expression of PRKAG2-AS1 in endothelial cells induced inflammation and apoptosis by reducing PRKAG2 expression

PRKAG2 is required for the maintenance of cellular energy balance. PRKAG2-AS1, a long non-coding RNA (lncRNA), was found within the promoter region of PRKAG2. Despite the extensive expression of PRKAG2-AS1 in endothelial cells, the precise function and mechanism of this gene in endothelial cells have yet to be elucidated. The localization of PRKAG2-AS1 was predominantly observed in the nucleus, as revealed using nuclear and cytoplasmic fractionation and fluorescence in situ hybridization. The manipulation of PRKAG2-AS1 by knockdown and overexpression within the nucleus significantly altered PRKAG2 expression in a cis-regulatory manner. The expression of PRKAG2-AS1 and its target genes, PRKAG2b and PRKAG2d, was down-regulated in endothelial cells subjected to oxLDL and Hcy-induced injury. This finding suggests that PRKAG2-AS1 may be involved in the mechanism behind endothelial injury. The suppression of PRKAG2-AS1 specifically in the nucleus led to an upregulation of inflammatory molecules such as cytokines, adhesion molecules, and chemokines in endothelial cells. Additionally, this nuclear suppression of PRKAG2-AS1 facilitated the adherence of THP1 cells to endothelial cells. We confirmed the role of nuclear knockdown PRKAG2-AS1 in the induction of apoptosis and inhibition of cell proliferation, migration, and lumen formation through flow cytometry, TUNEL test, CCK8 assay, and cell scratching. Finally, it was determined that PRKAG2-AS1 exerts direct control over the transcription of PRKAG2 by its binding to their promoters. In conclusion, downregulation of PRKAG2-AS1 suppressed the proliferation and migration, promoted inflammation and apoptosis of endothelial cells, and thus contributed to the development of atherosclerosis resulting from endothelial cell injury.

Endothelial dysfunction of syphilis: Pathogenesis.

Treponema pallidum is the causative factor of syphilis, a sexually transmitted disease (STD) characterized by perivascular infiltration of inflammatory cells, vascular leakage, swelling and proliferation of endothelial cells (ECs). The endothelium lining blood and lymphatic vessels is a key barrier separating body fluids from host tissues and is a major target of T. pallidum. In this review, we focus on how T. pallidum establish intimate interactions with ECs, triggering endothelial dysfunction such as endothelial inflammation, abnormal repairment and damage of ECs. In addition, we summarize that migration and invasion of T. pallidum across vascular ECs may occur through two pathways. These two mechanisms of transendothelial migration are paracellular and cholesterol-dependent, respectively. Herein, clarifying the relationship between T. pallidum and endothelial dysfunction is of great significance to provide novel strategies for diagnosis and prevention of syphilis, and has a great potential prospect of clinical application.

P65/NLRP3 Inflammasome Mediated Endothelial Cells Pyroptosis: A Novel Mechanism of In-Stent Restenosis

Background: In-stent restenosis (ISR) is one of the key causes of ischemic events after coronary stent implantation, and endothelial cell death and inflammation are considered to be important mechanisms. Pyroptosis is a proinflammatory type of programmed cell death, the effects and underlying mechanisms of endothelial cell (EC) pyroptosis in ISR remains unclear. Method: According to our previous work, an ISR rabbit model was established. Rabbits were divided into sham operation group and stent group. Serum was collected at 0, 4, 8, and 12 weeks to detect interleukin (IL)-1β and IL-18 levels. Rabbits' vascular EC was collected to detect NLRP3, Caspase1, GSDMD and P65 expression by western blot. NLRP3 inhibitor (MCC950) and P65 inhibitor (Helenalin) were used to pretreat EC, cell viability, lactate dehydrogenase (LDH) level of supernatant and pyroptosis related protein expression were measured in different groups. Results: The serum levels of IL-1β and IL-18 gradually increased with time, and the levels at the site of stent implantation were higher than the peripheral level. EC viability decreased significantly in the stent group, and protein levels of NLRP3, caspase1 and GSDMD were higher than those in the sham group. MCC950 and P65 inhibitors can reverse these effects. Conclusions: EC pyroptosis mediated by P65/NLRP3 inflammasome axis may promote ISR, our results provide a potential intervention target for the treatment of ISR.

Sevoflurane alleviates inflammation, apoptosis and permeability damage of human umbilical vein endothelial cells induced by lipopolysaccharide by inhibiting endoplasmic reticulum stress via upregulating RORα

Endothelial dysfunction often accompanies sepsis. Sevoflurane (Sev) is a widely used inhaled anesthetic that has a protective effect on sepsis-associated damage. We aimed to elucidate the role of Sev in endothelial dysfunction by using a model of LPS induced HUVECs. Sev increased the viability and decreased the apoptosis of HUVECs exposed to LPS. Inflammation and endothelial cell adhesion were improved after Sev addition. Besides, Sev alleviated LPS-induced endothelial cell permeability damage in HUVECs. RORα served as a potential protein that bound to Sev. Importantly, Sev upregulated RORα expression and inhibited endoplasmic reticulum (ER) stress in LPS-treated HUVECs. RORα silencing reversed the impacts of Sev on ER stress. Moreover, RORα deficiency or tunicamycin (ER stress inducer) treatment restored the effects of Sev on the viability, apoptosis, inflammation and endothelial permeability damage of HUVECs exposed to LPS. Taken together, Sev ameliorated LPS-induced endothelial cell damage by targeting RORα to inhibit ER stress.

Nrf2-mediated redox balance alleviates LPS-induced vascular endothelial cell inflammation by inhibiting endothelial cell ferroptosis

Ferroptosis plays an important role in inflammation and oxidative stress. Whether ferroptosis is involved in the inflammation of vascular endothelial cells and its regulation mechanism remains unclear. We estimated the correlation between serum iron ion levels and the inflammation index of 33 patients with arteriosclerosis. In vitro, HUVECs with or without ferrostatin-1 were exposed to Lipopolysaccharide. Corresponding cell models to verify the target signaling pathway. The results showed that serum iron ion levels had a significant positive correlation with N ratio, N/L, LDL level, and LDL/HDL (P < 0.05), and a negative correlation with L ratio (P < 0.05) in the arteriosclerosis patients. In vitro, ferroptosis is involved in HUVECs inflammation. Ferrostatin-1 can rescue LPS-induced HUVECs inflammation by decreasing HMGB1/IL-6/TNF-α expression. Nrf2 high expression could protect HUVECs against ferroptosis by activating the GPX4/GSH system, inhibiting ferritinophagy, and alleviating inflammation in HUVECs by inhibiting HMGB1/IL-6/TNF-α expression. It also found that Nrf2 is a key adaptive regulatory factor in the oxidative damage of HUVECs induced by NOX4 activation. These findings indicated that ferroptosis contributed to the pathogenesis of vascular endothelial cell damage by mediating endothelial cell inflammation. Nrf2-mediated redox balance in vascular inflammation may be a therapeutic strategy in vascular diseases.

The deubiquitinase USP40 preserves endothelial integrity by targeting the heat shock protein HSP90β

Endothelial cell (EC) barrier disruption and inflammation are the pathological hallmarks of vascular disorders and acute infectious diseases and related conditions, including the coronavirus disease 2019 (COVID-19) and sepsis. Ubiquitination plays a critical role in regulating the stability, intracellular trafficking, and enzymatic activity of proteins and is reversed by deubiquitinating enzymes (DUBs). The role of DUBs in endothelial biology is largely unknown. In this study, we report that USP40, a poorly characterized DUB, prevents EC barrier disruption through reductions in the activation of RhoA and phosphorylation of myosin light chain (MLC) and cofilin. Furthermore, USP40 reduces EC inflammation through the attenuation of NF-ĸB activation, ICAM1 expression, and leukocyte-EC adhesion. We further show that USP40 activity and expression are reduced in response to endotoxin challenge. Global depletion of USP40 and EC-targeted USP40 depletion in mice exacerbated experimental lung injury, whereas lentiviral gene transfer of USP40 protected against endotoxin-induced lung injury. Using an unbiased approach, we discovered that the protective effect of USP40 occurs through the targeting of heat shock protein 90β (HSP90β) for its deubiquitination and inactivation. Together, these data reveal a critical protective role of USP40 in vascular injury, identifying a unique mechanistic pathway that profoundly impacts endothelial function via DUBs.

INFLAMED INTESTINAL ENDOTHELIAL CELLS ESTABLISH SELF-REGULATORY NICHES VIA IL16 DEPENDENT RECRUITMENT OF CD4 EXPRESSING VESSEL-ASSOCIATED MACROPHAGES

Abstract Macrophages, play important roles in initiation and resolution of inflammation. Notably, a subset of tissue macrophages strategically localizes to the blood vessels, exerting essential regulatory functions at the blood-tissue interface, including regulation of vascular permeability and neutrophil (PMN) transendothelial migration (TEM). Although the number of vessel-associated macrophages (VAMs) is increased in inflamed tissue, the underlying mechanisms of VAMs recruitment are unknown. Our current study uncovers a novel mechanism whereby inflamed intestinal vascular endothelial cells (ECs) release IL-16 to selectively recruit CD4+ tissue macrophages to become VAMs. Whole-mount confocal microscopy studies in CX3CR1-EGFP macrophages reporter mice confirmed significant increases in VAMs numbers in several murine models of intestinal inflammation. Surprisingly, the majority of VAMs were found to express a classical T cell marker, CD4 and to be of an inflammatory phenotype, enriched for ICAM-1 and TNFα expression. VAMs-derived TNFα was previously found to prime ECs to form PMN TEM hot spots. Whole genome mRNA sequencing, and flow cytometry protein expression analyses revealed heightened expression of the CD4 ligand, IL-16 by inflamed intestinal lamina propria ECs. In vitro, using transwell assays, recombinant IL-16 and supernatants derived from murine (bEnds.3) endothelial cells induced robust migration of murine, LPS/IFNγ-stimulated bone marrow-derived macrophages. Whereas antibody-mediated IL-16 or CD4 neutralization in cultures and in vivo reduced VAMs recruitment. Collectively, our findings establish CD4 as a novel marker of VAMs and identify the regulatory role of ECs IL-16 and macrophages CD4+ axis in VAMs recruitment in inflamed mucosal tissues.

Single-cell RNA sequencing unveils unique transcriptomic signatures of endothelial cells and role of ENO1 in response to disturbed flow

Flow patterns exert significant effects on vascular endothelial cells (ECs) to lead to the focal nature of atherosclerosis. Using a step flow chamber to investigate the effects of disturbed shear (DS) and pulsatile shear (PS) on ECs in the same flow channel, we conducted single-cell RNA sequencing analyses to explore the distinct transcriptomic profiles regulated by DS vs. PS. Integrated analysis identified eight cell clusters and demonstrated that DS induces EC transition from atheroprotective to proatherogenic phenotypes. Using an automated cell type annotation algorithm (SingleR), we showed that DS promoted endothelial-to-mesenchymal transition (EndMT) by inducing the transcriptional phenotypes for inflammation, hypoxia responses, transforming growth factor-beta (TGF-β) signaling, glycolysis, and fatty acid synthesis. Enolase 1 (ENO1), a key gene in glycolysis, was one of the top-ranked genes in the DS-induced EndMT cluster. Pseudotime trajectory analysis revealed that the kinetic expression of ENO1 was significantly associated with EndMT and that ENO1 silencing repressed the DS- and TGF-β-induced EC inflammation and EndMT. Consistent with these findings, ENO1 was highly expressed in ECs at the inner curvature of the mouse aortic arch (which is exposed to DS) and atherosclerotic lesions, suggesting its proatherogenic role in vivo. In summary, we present a comprehensive single-cell atlas of ECs in response to different flow patterns within the same flow channel. Among the DS-regulated genes, ENO1 plays an important role in DS-induced EC inflammation and EndMT. These results provide insights into how hemodynamic forces regulate vascular endothelium in health and disease.

SMPDL3B is palmitoylated and stabilized by ZDHHC5, and its silencing aggravates diabetic retinopathy of db/db mice: Activation of NLRP3/NF-κB pathway

Abnormal inflammation of vascular endothelial cells occurs frequently in diabetic retinopathy (DR). Sphingomyelin phosphodiesterase acid-like 3B (SMPDL3B) is a lipid raft enzyme and plays an anti-inflammatory role in various diseases but its function in DR-related vascular endothelial dysfunction remains unknown. We first found that SMPDL3B expression was upregulated from week 10 to 18 in the retinal tissues of db/db mice. Particularly, the high expression of SMPDL3B was mainly observed in retinal vascular endothelium of DR mice. To interfere retinal SMPDL3B expression, adeno-associated viruses 2 (AAV-2) containing SMPDL3B specific shRNA (1233–1253 bp) were injected into the vitreous cavity of db/db mice. SMPDL3B silencing exacerbated the spontaneous DR by further activating the NF-κB/NLRP3 pro-inflammatory pathway. In vitro, human retinal microvascular endothelial cells (HRVECs) were infected with SMPDL3B-shRNA lentiviruses and then stimulated with 30 mM glucose (HG) for 24 h. SMPDL3B-silenced HRVECs secreted more interleukin-1β and had enhanced nuclear p65 translocation. Notably, HG treatment induced the palmitoylation of SMPDL3B. Zinc finger DHHC-type palmitoyltransferase 5 (ZDHHC5) is a palmitoyltransferase that catalyzes the palmitoylation of its substrates, HG exposure increased the interaction between ZDHHC5 and SMPDL3B in HRVECs. 2-BP, a palmitoylation inhibitor, accelerated the protein degradation of SMPDL3B, whereas palmostatin B, a depalmitoylation inhibitor, decreased its turnover rate in HRVECs. Collectively, the present study suggests a compensatory increase of SMPDL3B in HG-treated HRVECs and the retinal tissues of DR mice, indicating that SMPDL3B may be a potential target for DR treatment.

Identification of KU-55933 as an anti-atherosclerosis compound by using a hemodynamic-based high-throughput drug screening platform

Several compounds have been used for atherosclerosis treatment, including clinical trials; however, no anti-atherosclerotic drugs based on hemodynamic force-mediated atherogenesis have been discovered. Our previous studies demonstrated that "small mothers against decapentaplegic homolog 1/5" (Smad1/5) is a convergent signaling molecule for chemical [e.g., bone morphogenetic proteins (BMPs)] and mechanical (e.g., disturbed flow) stimulations and hence may serve as a promising hemodynamic-based target for anti-atherosclerosis drug development. The goal of this study was to develop a high-throughput screening (HTS) platform to identify potential compounds that can inhibit disturbed flow- and BMP-induced Smad1/5 activation and atherosclerosis. Through HTS using a Smad1/5 downstream target inhibitor of DNA binding 1 (Id-1) as a luciferase reporter, we demonstrated that KU-55933 and Apicidin suppressed Id-1 expression in AD-293 cells. KU-55933 (10 μM), Apicidin (10 μM), and the combination of half doses of each [1/2(K + A)] inhibited disturbed flow- and BMP4-induced Smad1/5 activation in human vascular endothelial cells (ECs). KU-55933, Apicidin, and 1/2(K + A) treatments caused 50.6%, 47.4%, and 73.3% inhibitions of EC proliferation induced by disturbed flow, respectively, whereas EC inflammation was only suppressed by KU-55933 and 1/2(K + A), but not Apicidin alone. Administrations of KU-55933 and 1/2(K + A) to apolipoprotein E-deficient mice inhibited Smad1/5 activation in ECs in athero-susceptible regions, thereby suppressing endothelial proliferation and inflammation, with the attenuation of atherosclerotic lesions in these mice. A unique drug screening platform has been developed to demonstrate that KU-55933 and its combination with Apicidin are promising therapeutic compounds for atherosclerosis based on hemodynamic considerations.

Spatial multiomics of arterial regions from cardiac allograft vasculopathy rejected grafts reveal novel insights into the pathogenesis of chronic antibody-mediated rejection

Cardiac allograft vasculopathy (CAV) causes late graft failure and mortality after heart transplantation. Donor-specific antibodies (DSAs) lead to chronic endothelial cell injury, inflammation, and arterial intimal thickening. In this study, GeoMx digital spatial profiling was used to analyze arterial areas of interest (AOIs) from CAV+DSA+ rejected cardiac allografts (N = 3; 22 AOIs total). AOIs were categorized based on CAV neointimal thickening and underwent whole transcriptome and protein profiling. By comparing our transcriptomic data with that of healthy control vessels of rapid autopsy myocardial tissue, we pinpointed specific pathways and transcripts indicative of heightened inflammatory profiles in CAV lesions. Moreover, we identified protein and transcriptomic signatures distinguishing CAV lesions exhibiting low and high neointimal lesions. AOIs with low neointima showed increased markers for activated inflammatory infiltrates, endothelial cell activation transcripts, and gene modules involved in metalloproteinase activation and TP53 regulation of caspases. Inflammatory and apoptotic proteins correlated with inflammatory modules in low neointima AOIs. High neointima AOIs exhibited elevated TGFβ-regulated transcripts and modules enriched for platelet activation/aggregation. Proteins associated with growth factors/survival correlated with modules enriched for proliferation/repair in high neointima AOIs. Our findings reveal novel insight into immunological mechanisms mediating CAV pathogenesis.

The pathogenesis and therapeutic strategies of heat stroke-induced myocardial injury.

Heat stroke (HS) is a febrile illness characterized by an elevation in the core body temperature to over 40°C, accompanied by central nervous system impairment and subsequent multi-organ dysfunction syndrome. In recent years, the mortality rate from HS has been increasing as ambient temperatures continue to rise each year. The cardiovascular system plays an important role in the pathogenesis process of HS, as it functions as one of the key system for thermoregulation and its stability is associated with the severity of HS. Systemic inflammatory response and endothelial cell damage constitute pivotal attributes of HS, other factors such as ferroptosis, disturbances in myocardial metabolism and heat shock protein dysregulation are also involved in the damage to myocardial tissue in HS. In this review, a comprehensively detailed description of the pathogenesis of HS-induced myocardial injury is provided. The current treatment strategies and the promising therapeutic targets for HS are also discussed.