Endothelial-mesenchymal Transition Research Articles

Inhibition of cytochrome P450 epoxygenase promotes endothelium-to-mesenchymal transition and exacerbates doxorubicin-induced cardiovascular toxicity

BackgroundDoxorubicin (DOX) is a potent chemotherapy widely used in treating various neoplastic diseases. However, the clinical use of DOX is limited due to its potential toxic effect on the cardiovascular system. Thus, identifying the pathway involved in this toxicity may help minimize chemotherapy risk and improve cancer patients’ quality of life. Recent studies suggest that Endothelial-to-Mesenchymal transition (EndMT) and endothelial toxicity contribute to the pathogenesis of DOX-induced cardiovascular toxicity. However, the molecular mechanism is yet unknown. Given that arachidonic acid and associated cytochrome P450 (CYP) epoxygenase have been involved in endothelial and cardiovascular function, we aimed to examine the effect of suppressing CYP epoxygenases on DOX-induced EndMT and cardiovascular toxicity in vitro and in vivo.Methods and ResultsTo test this, human endothelial cells were treated with DOX, with or without CYP epoxygenase inhibitor, MSPPOH. We also investigated the effect of MSPPOH on the cardiovascular system in our zebrafish model of DOX-induced cardiotoxicity. Our results showed that MSPPOH exacerbated DOX-induced EndMT, inflammation, oxidative stress, and apoptosis in our endothelial cells. Furthermore, we also show that MSPPOH increased cardiac edema, lowered vascular blood flow velocity, and worsened the expression of EndMT and cardiac injury markers in our zebrafish model of DOX-induced cardiotoxicity.ConclusionOur data indicate that a selective CYP epoxygenase inhibitor, MSPPOH, induces EndMT and endothelial toxicity to contribute to DOX-induced cardiovascular toxicity.

Inhibition of endothelial to mesenchymal transition in a large animal preclinical arterio-venous fistula model leads to improved remodeling and reduced stenosis.

Vein grafts are used for many indications, including bypass graft surgery and arterio-venous fistula (AVF) formation. However, patency following vein grafting or AVF formation is suboptimal for various reasons, including thrombosis, neointimal hyperplasia and adverse remodeling. Recently, endothelial to mesenchymal transition (EndMT) was found to contribute to neointimal hyperplasia in mouse vein grafts. We aimed to evaluate the clinical potential of inhibiting EndMT, and developed the first dedicated preclinical model to study the efficacy of local EndMT inhibition immediately prior to AVF creation. We first undertook pilot studies to optimize the creation of a femoral AVF in pigs and verify that EndMT contributes to neointimal formation. We then developed a method to achieve local in vivo SMAD3 knockdown by dwelling a lentiviral construct containing SMAD3 shRNA in the femoral vein prior to AVF creation. Next, in Phase 1, 6 pigs were randomized to SMAD3 knockdown or control lentivirus to evaluate the effectiveness of SMAD3 knockdown and EndMT inhibition 8 days after AVF creation. In Phase 2, 16 pigs were randomized to SMAD3 knockdown or control lentivirus and were evaluated to assess longer-term effects on AVF diameter, patency and related measures at 30 days after AVF creation.In Phase 1, compared to controls, SMAD3 knockdown achieved a 75% reduction in the proportion of CD31+ endothelial cells co-expressing SMAD3 (p<0.001), and also a significant reduction in the extent of EndMT (p<0.05). In Phase 2, compared to controls, SMAD3 knockdown was associated with an increase in the minimum diameter of the venous limb of the AVF (1.56±1.66 versus 4.26±1.71mm, p<0.01) and a reduced degree of stenosis (p<0.01). Consistent with this, neointimal thickness was reduced in the SMAD3 knockdown group (0.88±0.51 versus 0.45±0.19mm, p<0.05). Furthermore, endothelial integrity (the proportion of luminal cells expressing endothelial markers) was improved in the SMAD3 knockdown group (p<0.05). EndMT inhibition in a preclinical AVF model by local SMAD3 knockdown using gene therapy led to reduced neointimal hyperplasia, increased endothelialization and a reduction in the degree of AVF stenosis. This provides important proof-of-concept to pursue this approach as a clinical strategy to improve the patency of AVFs and other vein grafts.

Hyperoxia exposure promotes endothelial-mesenchymal transition and inhibits regulatory T cell function in human pulmonary microvascular endothelial cells.

This study aims to investigate the effects of hyperoxia exposure on TGF-β1-induced endothelial-mesenchymal transition (EndoMT) and regulatory T cell (Treg)-mediated immunomodulation in human pulmonary microvascular endothelial cells (HPMECs), which could provide a theoretical basis for further studies of the pathogenesis of bronchopulmonary dysplasia (BPD). A BPD cell model was established by exposing HPMECs to hyperoxia. Flow cytometry was used to isolate CD4 + CD3 + CD25 + CD127- Tregs from the peripheral blood samples of preterm infants. HPMECs were divided into four groups based on whether they were exposed to hyperoxia and/or co-cultured with Tregs. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and enzyme-linked immunosorbent assay (ELISA) were used to test the expression levels of TGF-β1, α-SMA, Foxp3, IL-10, and reactive oxygen species (ROS). The results showed that the expression levels of TGF-β1 and α-SMA in HPMECs increased at 24 h, 48 h, and 72 h of hyperoxia exposure. In the co-culture group of HPMECs and Tregs, Foxp3 and IL-10 expressions decreased at 48 h and 72 h of hyperoxia exposure. ROS expression increased in the hyperoxia group of HPMECs at 24 h, 48 h, and 72 h of hyperoxia exposure, which were higher than those in the hyperoxia group of HPMECs and Tregs. These findings suggest that hyperoxia exposure promotes EndoMT in HMPECs and inhibits the immunosuppressive effect of Tregs. Despite this, Tregs still seem could protect HPMECs from oxidative stress injury.

Enhanced Migration of Fuchs Corneal Endothelial Cells by Rho Kinase Inhibition: A Novel Ex Vivo Descemet's Stripping Only Model.

Descemet's Stripping Only (DSO) is a surgical technique that utilizes the peripheral corneal endothelial cell (CEnC) migration for wound closure. Ripasudil, a Rho-associated protein kinase (ROCK) inhibitor, has shown potential in DSO treatment; however, its mechanism in promoting CEnC migration remains unclear. We observed that ripasudil-treated immortalized normal and Fuchs endothelial corneal dystrophy (FECD) cells exhibited significantly enhanced migration and wound healing, particularly effective in FECD cells. Ripasudil upregulated mRNA expression of Snail Family Transcriptional Repressor (SNAI1/2) and Vimentin (VIM) while decreasing Cadherin (CDH1), indicating endothelial-to-mesenchymal transition (EMT) activation. Ripasudil activated Rac1, driving the actin-related protein complex (ARPC2) to the leading edge, facilitating enhanced migration. Ex vivo studies on cadaveric and FECD Descemet's membrane (DM) showed increased migration and proliferation of CEnCs after ripasudil treatment. An ex vivo DSO model demonstrated enhanced migration from the DM to the stroma with ripasudil. Coating small incision lenticule extraction (SMILE) tissues with an FNC coating mix and treating the cells in conjunction with ripasudil further improved migration and resulted in a monolayer formation, as detected by the ZO-1 junctional marker, thereby leading to the reduction in EMT. In conclusion, ripasudil effectively enhanced cellular migration, particularly in a novel ex vivo DSO model, when the stromal microenvironment was modulated. This suggests ripasudil as a promising adjuvant for DSO treatment, highlighting its potential clinical significance.

SGLT2 inhibitors attenuate endothelial to mesenchymal transition and cardiac fibroblast activation

Beneficial effects of sodium glucose co-transporter 2 inhibitors (SGLT2is) in cardiovascular diseases have been extensively reported leading to the inclusion of these drugs in the treatment guidelines for heart failure. However, molecular actions especially on non-myocyte cells remain uncertain. We observed dose-dependent inhibitory effects of two SGLT2is, dapagliflozin (DAPA) and empagliflozin (EMPA), on inflammatory signaling in human umbilical vein endothelial cells. Proteomic analyses and subsequent enrichment analyses discovered profound effects of these SGLT2is on proteins involved in mitochondrial respiration and actin cytoskeleton. Validation in functional oxygen consumption measurements as well as tube formation and migration assays revealed strong impacts of DAPA. Considering that most influenced parameters played central roles in endothelial to mesenchymal transition (EndMT), we performed in vitro EndMT assays and identified substantial reduction of mesenchymal and fibrosis marker expression as well as changes in cellular morphology upon treatment with SGLT2is. In line, human cardiac fibroblasts exposed to DAPA showed less proliferation, reduced ATP production, and decelerated migration capacity while less extensive impacts were observed upon EMPA. Mechanistically, sodium proton exchanger 1 (NHE1) as well as sodium-myoinositol cotransporter (SMIT) and sodium-multivitamin cotransporter (SMVT) could be identified as relevant targets of SGLT2is in non-myocyte cardiovascular cells as validated by individual siRNA-knockdown experiments. In summary, we found comprehensive beneficial effects of SGLT2is on human endothelial cells and cardiac fibroblasts. The results of this study therefore support a distinct effect of selected SGLT2i on non-myocyte cardiovascular cells and grant further insights into potential molecular mode of action of these drugs.

CircZNF532 promotes endothelial-to-mesenchymal transition in diabetic retinopathy by recruiting TAF15 to stabilize PIK3CD.

Endothelial-to-mesenchymal transition (EndMT) is a pivotal event in diabetic retinopathy (DR). This study explored the role of circRNA zinc finger protein 532 (circZNF532) in regulating EndMT in DR progression. Human retinal microvascular endothelial cells (HRMECs) were exposed to high glucose (HG) to induce the DR cell model. Actinomycin D-treated HRMECs were used to confirm the mRNA stability of phosphoinositide-3 kinase catalytic subunit δ (PIK3CD). The interaction between TATA-box-binding protein-associated factor 15 (TAF15) and circZNF532/PIK3CD was subsequently analyzed using RNA immunoprecipitation (RIP), RNA pull-down. It was found that HG treatment accelerated EndMT process, facilitated cell migration and angiogenesis, and enhanced PIK3CD and p-AKT levels in HRMECs, whereas si-circZNF532 transfection neutralized these effects. Further data showed that circZNF532 recruited TAF15 to stabilize PIK3CD, thus elevating PIK3CD expression. Following rescue experiments suggested that PIK3CD overexpression partially negated the inhibitory effect of circZNF532 silencing on EndMT, migration, and angiogenesis of HG-treated HRMECs. In conclusion, our results suggest that circZNF532 recruits TAF15 to stabilize PIK3CD, thereby facilitating EndMT in DR.

LncRNAH19 acts as a ceRNA of let-7 g to facilitate endothelial-to-mesenchymal transition in hypoxic pulmonary hypertension via regulating TGF-β signalling pathway

BackgroundHypoxic pulmonary hypertension (HPH) is a challenging lung arterial disorder with remarkably high incidence and mortality rates, and the efficiency of current HPH treatment strategies is unsatisfactory. Endothelial-to-mesenchymal transition (EndMT) in the pulmonary artery plays a crucial role in HPH. Previous studies have shown that lncRNA-H19 (H19) is involved in many cardiovascular diseases by regulating cell proliferation and differentiation but the role of H19 in EndMT in HPH has not been defined.MethodsIn this research, the expression of H19 was investigated in PAH human patients and rat models. Then, we established a hypoxia-induced HPH rat model to evaluate H19 function in HPH by Echocardiography and hemodynamic measurements. Moreover, luciferase reporter gene detection, and western blotting were used to explore the mechanism of H19.ResultsHere, we first found that the expression of H19 was significantly increased in the endodermis of pulmonary arteries and that H19 deficiency obviously ameliorated pulmonary vascular remodelling and right heart failure in HPH rats, and these effects were associated with inhibition of EndMT. Moreover, an analysis of luciferase activity indicated that microRNA-let-7 g (let-7 g) was a direct target of H19. H19 deficiency or let-7 g overexpression can markedly downregulate the expression of TGFβR1, a novel target gene of let-7 g. Furthermore, inhibition of TGFβR1 induced similar effects to H19 deficiency.ConclusionsIn summary, our findings demonstrate that the H19/let-7 g/TGFβR1 axis is crucial in the pathogenesis of HPH by stimulating EndMT. Our study may provide new ideas for further research on HPH therapy in the near future.

Anti-IL-17 Inhibits PINK1/Parkin Autophagy and M1 Macrophage Polarization in Rheumatic Heart Disease.

Rheumatic heart disease (RHD) is an important and preventable cause of cardiovascular death and disability, but the lack of clarity about its exact mechanisms makes it more difficult to find alternative methods or prevention and treatment. We previously demonstrated that increased IL-17 expression plays a crucial role in the development of RHD-related valvular inflammatory injury. Macrophage autophagy/polarization may be a pro-survival strategy in the initiation and resolution of the inflammatory process. This study investigated the mechanism by which IL-17 regulates autophagy/polarization activation in macrophages. A RHD rat model was generated, and the effects of anti-IL-17 and 3-methyladenine (3-MA) were analyzed. The molecular mechanisms underlying IL-17-induced macrophage autophagy/polarization were investigated via in vitro experiments. In our established RHD rat model, the activation of the macrophage PINK1/Parkin autophagic pathway in valve tissue was accompanied by M1 macrophage infiltration, and anti-IL-17 treatment inhibited autophagy and reversed macrophage inflammatory infiltration, thereby attenuating endothelial-mesenchymal transition (EndMT) in the valve tissue. The efficacy of 3-MA treatment was similar to that of anti-IL-17 treatment. Furthermore, in THP-1 cells, the pharmacological promotion of autophagy by IL-17 induced M1-type polarization, whereas the inhibition of autophagy by 3-MA reversed this process. Mechanistically, silencing PINK1 in THP-1 blocked autophagic flux. Moreover, IL-17-induced M1-polarized macrophages promoted EndMT in HUVECs. This study revealed that IL-17 plays an important role in EndMT in RHD via the PINK1/Parkin autophagic pathway and macrophage polarization, providing a potential therapeutic target.

SARS-CoV-2-related peptides induce endothelial-to-mesenchymal transition in endothelial capillary cells derived from different body districts: focus on membrane (M) protein.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), responsible for the COVID-19, may lead to multiple organ dysfunctions and long-term complications. The induction of microvascular dysfunction is regarded as a main player in these pathological processes. To investigate the possible impact of SARS-CoV-2-induced endothelial-to-mesenchymal transition (EndMT) on fibrosis in "long-COVID" syndrome, we used primary cultures of human microvascular cells derived from the lungs, as the main infection target, compared to cells derived from different organs (dermis, heart, kidney, liver, brain) and to the HUVEC cell line. To mimic the virus action, we used mixed SARS-CoV-2 peptide fragments (PepTivator®) of spike (S), nucleocapsid (N), and membrane (M) proteins. TGFβ2 and cytokine mix (IL-1β, IL-6, TNFα) were used as positive controls. The percentage of cells positive to mesenchymal and endothelial markers was quantified by high content screening. We demonstrated that S+N+M mix induces irreversible EndMT in all analyzed endothelial cells via the TGFβ pathway, as demonstrated by ApoA1 treatment. We then tested the contribution of single peptides in lung and brain cells, demonstrating that EndMT is triggered by M peptide. This was confirmed by transfection experiment, inducing the endogenous expression of the glycoprotein M in lung-derived cells. In conclusion, we demonstrated that SARS-CoV-2 peptides induce EndMT in microvascular endothelial cells from multiple body districts. The different peptides play different roles in the induction and maintenance of the virus-mediated effects, which are organ-specific. These results corroborate the hypothesis of the SARS-CoV-2-mediated microvascular damage underlying the multiple organ dysfunctions and the long-COVID syndrome.

Cannabinoid 2 receptor activation protects against diabetic cardiomyopathy through inhibition of AGE/RAGE-induced oxidative stress, fibrosis, and inflammasome activation.

Oxidative stress, fibrosis, and inflammasome activation from AGE-RAGE interaction contribute to diabetic cardiomyopathy (DCM) formation and progression. Our study revealed the impact of β-caryophyllene (BCP) on activating CB2 receptors against diabetes complications and investigated the underlying cell signaling pathways in mice. The murine model of DCM was developed by feeding high-fat diet with streptozotocin injections. After the development of diabetes, the animals received a 12-week oral BCP treatment at a dosage of 50 mg/kg/body weight. BCP treatment showed significant improvement in glucose tolerance, insulin resistance, and enhanced serum insulin levels in diabetic animals. BCP treatment effectively reversed the heart remodeling and restored the phosphorylated troponin I and SERCA2a expression. Ultrastructural examination showed reduced myocardial cell injury in DCM mice treated with BCP. The preserved myocytes were found associated with reduced expression of AGE/RAGE in DCM mice hearts. BCP treatment mitigated oxidative stress by inhibiting expression of NOX4 and activating PI3K/AKT/Nrf2 signaling. BCP suppressed cardiac fibrosis and endothelial-to-mesenchymal transition (EndMT) in DCM mice by inhibiting TGF-β/Smad signaling. Further, BCP treatment suppressed NLRP3 inflammasome activation in DCM mice and alleviated cellular injury to the pancreatic tissues evidenced by significant elevation of the number of insulin-positive cells. To demonstrate CB2 receptor dependent mechanism of BCP, another group of DCM mice were pretreated with AM630, a CB2 receptor antagonist AM630 and AM630 was observed to abrogate the beneficial effects of BCP in DCM mice. Taken together, BCP showed the potential to protect the myocardium and pancreas of DCM mice mediating CB2 receptor dependent mechanisms. Significance Statement 1. β-caryophyllene (BCP), a cannabinoid type 2 receptor (CB2R) agonist. 2. BCP attenuates diabetic cardiomyopathy via activating CB2R in mice 3. CB2R activation by BCP shows strong protection against fibrosis and inflammasome activation 4. It regulates AGE/RAGE and PI3K/Nrf2/Akt signaling in mice.

Mechanistic investigation of wogonin in delaying the progression of endothelial mesenchymal transition by targeting the TGF-β1 pathway in pulmonary hypertension

Pulmonary hypertension (PH) is characterized by pulmonary vascular remodeling, which endothelial-to-mesenchymal transition (EndMT) being its main progressive phase. Wogonin, a flavonoid extracted from the root of Scutellaria baicalensis Georgi, hinders the abnormal proliferation of cells and has been employed in the treatment of several cardiopulmonary diseases. This study was designed to investigate how wogonin affected EndMT during PH. Monocrotaline (MCT) was used to induce PH in rats. Binding capacity of TGF-β1 receptor to wogonin detected by molecular docking and molecular dynamics. EndMT model was established in pulmonary microvascular endothelial cells (PMVECs) by transforming growth factor beta-1 (TGF-β1). The result demonstrated that wogonin (20 mg/kg/day) attenuated right ventricular systolic pressure (RVSP), right ventricular hypertrophy and pulmonary vascular thickness in PH rats. EndMT in the pulmonary vascular was inhibited after wogonin treatment as evidenced by the restored expression of CD31 and decreased expression of α-SMA. Wogonin has strong affinity for both TGFBRI and TGFBRII, and has a better binding stability for TGFBRI. In TGF-β1-treated PMVECs, wogonin (0.3, 1, and 3 μM) exhibited significant inhibitory effects on this transformation process via down-regulating the expression of p-Smad2 and Snail, while up-regulating the expression of p-Smad1/5. Additionally, results of Western blot and fluorescence shown that the expression of α-SMA were decrease with increasing level of CD31 in PMVECs. In conclusion, our research showed that wogonin suppressed EndMT via the TGF-β1/Smad pathway which may lead to its alleviated effect on PH. Wogonin may be a promising drug against PH.

Post-treatment with Resolvin D1 attenuates pulmonary hypertension by inhibiting endothelial-to-mesenchymal transition

Pulmonary hypertension (PH) is a life-threatening disease characterized by pulmonary vascular remodeling. Endothelial-to-mesenchymal transition (EndMT) is an important manifestation and mechanism of pulmonary vascular remodeling. Resolvin D1 (RvD1) is an endogenous lipid mediator promoting the resolution of inflammation. However, the role of RvD1 on EndMT in PH remains unknown. Here, we aimed to investigate the effect and mechanisms of RvD1 on the treatment of PH. We showed that RvD1 and its receptor FPR2 expression were markedly decreased in PH patients and both chronic hypoxia-induced PH (CH-PH) and sugen 5416/hypoxia-induced PH (SuHx-PH) mice models. RvD1 treatment decreased right ventricular systolic pressure (RVSP) and alleviated right ventricular function, and reduced pulmonary vascular remodeling and collagen deposition in the perivascular of both two PH mice models. Then, RvD1 inhibited EndMT in both the lungs of PH mice models and primary cultured human umbilical vein endothelial cells (HUVECs) treated with TGF-β and IL-1β. Moreover, RvD1 inhibited EndMT by downregulating Smad2/3 phosphorylation in vivo and in vitro via FPR2. In conclusion, our date suggest that RvD1/FPR2 axis prevent experimental PH by inhibiting endothelial-mensenchymal-transition and may be a therapeutic target for PH.

Platelets could be key regulators of epithelial/endothelial-to- mesenchymal transition in atherosclerosis and wound healing

Atherosclerosis and wound healing are complex pathophysiological processes involving multiple cell types, including endothelial cells and platelets. Endothelial-to-mesenchymal transition (EndMT) involves the transformation of endothelial cells into mesenchymal cells. This transition serves as a critical mechanism in vascular remodeling, essential for both atherosclerosis pathogenesis and wound healing. On the other hand, epithelial-to-mesenchymal transition (EMT), which involves the transformation of epithelial cells into mesenchymal cells, is crucial for wound healing. Platelets are known to release various growth factors and cytokines which are integral to wound healing and tissue repair, although their direct role in the modulation of EndMT and EMT remains unclear. However, a few studies have shown a potential mechanistic link between platelet activity and these cellular transitions. Since EndMT and EMT play a critical role in vascular remodeling and tissue repair, respectively, it is plausible that these processes are modulated by platelets, which are known for their dynamic and context-dependent release of growth factors and cytokines.Therefore, we postulate that platelets significantly impact the progression of atherosclerosis through the modulation of EndMT, and that of wound healing through the regulation of both EndMT and EMT. The influence of platelets on these processes can have both beneficial and detrimental effects. This hypothesis represents a significant advance in our understanding of the complex interplay between platelets, cellular phenotype, and disease pathophysiology. Elucidating the specific mechanisms by which platelets modulate EMT and EndMT could pave the way for innovative therapeutic strategies that harness the body’s innate capacity for repair and regeneration, thereby enhancing clinical outcomes for these conditions.

Tumor microenvironment characteristics of lipid metabolism reprogramming related to ferroptosis and EndMT influencing prognosis in gastric cancer

BackgroundGastric cancer (GC) is a refractory malignant tumor with high tumor heterogeneity, a low rate of early diagnosis, and poor patient prognosis. Lipid metabolism reprogramming plays a critical role in tumorigenesis and progression, but its prognostic role and regulatory mechanism in GC are rarely studied. Thus, the identification of signatures related to lipid metabolism is necessary and may present a new avenue for improving the overall prognosis of GC. MethodsLipid metabolism-associated genes (LMAGs) with differential expression in tumor and tumor-adjacent tissue were acquired to identify lipid metabolism-associated subtypes. The differentially expressed genes (DEGs) between the two clusters were then utilized for prognostic analysis and signature construction. Additionally, pathway enrichment analysis and immune cell infiltration analysis were employed to identify the characteristics of the prognostic model. Further analyses were conducted at the single-cell level to better understand the model’s prognostic mechanism. Finally, the prediction of immunotherapy response was used to suggest potential treatments. ResultsTwo lipid metabolism-associated subtypes were identified and 9 prognosis-related genes from the DEGs between the two clusters were collected for the construction of the prognostic model named lipid metabolism-associated signature (LMAS). Then we found the low LMAS patients with favorable prognoses were more sensitive to ferroptosis in the Cancer Genome Atlas of Stomach Adenocarcinoma (TCGA-STAD). Meanwhile, the tumor cells exhibiting high levels of lipid peroxidation and accumulation of reactive oxygen species (ROS) in single-cell levels were primarily enriched in the low LMAS group, which was more likely to induce ferroptosis. In addition, endothelial cells and cancer-associated fibroblasts (CAFs) facilitated tumor angiogenesis, proliferation, invasion, and metastasis through endothelial-mesenchymal transition (EndMT), affecting the prognosis of the patients with high LMAS scores. Moreover, CD1C− CD141− dendritic cells (DCs) also secreted pro-tumorigenic cytokines to regulate the function of endothelial cells and CAFs. Finally, the patients with low LMAS scores might have better efficacy in immunotherapy. ConclusionsA LMAS was constructed to guide GC prognosis and therapy. Meanwhile, a novel anti-tumor effect was found in lipid metabolism reprogramming of GC which improved patients’ prognosis by regulating the sensitivity of tumor cells to ferroptosis. Moreover, EndMT may have a negative impact on GC prognosis.

CD163+ Macrophages Induce Endothelial-to-Mesenchymal Transition in Atheroma.

Cell phenotype switching is increasingly being recognized in atherosclerosis. However, our understanding of the exact stimuli for such cellular transformations and their significance for human atherosclerosis is still evolving. Intraplaque hemorrhage is thought to be a major contributor to plaque progression in part by stimulating the influx of CD163+ macrophages. Here, we explored the hypothesis that CD163+ macrophages cause plaque progression through the induction of proapoptotic endothelial-to-mesenchymal transition (EndMT) within the fibrous cap. Human coronary artery sections from CVPath's autopsy registry were selected for pathological analysis. Athero-prone ApoE-/- and ApoE-/-/CD163-/- mice were used for in vivo studies. Human peripheral blood mononuclear cell-induced macrophages and human aortic endothelial cells were used for in vitro experiments. In 107 lesions with acute coronary plaque rupture, 55% had pathological evidence of intraplaque hemorrhage in nonculprit vessels/lesions. Thinner fibrous cap, greater CD163+ macrophage accumulation, and a larger number of CD31/FSP-1 (fibroblast specific protein-1) double-positive cells and TUNEL (terminal deoxynucleotidyl transferase-dUTP nick end labeling) positive cells in the fibrous cap were observed in nonculprit intraplaque hemorrhage lesions, as well as in culprit rupture sections versus nonculprit fibroatheroma sections. Human aortic endothelial cells cultured with supernatants from hemoglobin/haptoglobin-exposed macrophages showed that increased mesenchymal marker proteins (transgelin and FSP-1) while endothelial markers (VE-cadherin and CD31) were reduced, suggesting EndMT induction. Activation of NF-κB (nuclear factor kappa β) signaling by proinflammatory cytokines released from CD163+ macrophages directly regulated the expression of Snail, a critical transcription factor during EndMT induction. Western blot analysis for cleaved caspase-3 and microarray analysis of human aortic endothelial cells indicated that apoptosis was stimulated during CD163+ macrophage-induced EndMT. Additionally, CD163 deletion in athero-prone mice suggested that CD163 is required for EndMT and plaque progression. Using single-cell RNA sequencing from human carotid endarterectomy lesions, a population of EndMT was detected, which demonstrated significant upregulation of apoptosis-related genes. CD163+ macrophages provoke EndMT, which may promote plaque progression through fibrous cap thinning.

Extracellular Vesicles Derived from Type 2 Diabetic Mesenchymal Stem Cells Induce Endothelial Mesenchymal Transition under High Glucose Conditions Through the TGFβ/Smad3 Signaling Pathway.

Type 2 diabetes mellitus (T2DM) is associated with endothelial dysfunction, which results in delayed wound healing. Mesenchymal stem cells (MSCs) play a vital role in supporting endothelial cells (ECs) and promoting wound healing by paracrine effects through their secretome-containing extracellular vesicles. We previously reported the impaired wound healing ability of adipose tissue-derived MSC from T2DM donors; however, whether extracellular vesicles isolated from T2DM adipose tissue-derived MSCs (dEVs) exhibit altered functions in comparison to those derived from healthy donors (nEVs) is still unclear. In this study, we found that nEVs induced EC survival and angiogenesis, whereas dEVs lost these abilities. In addition, under high glucose conditions, nEV protected ECs from endothelial-mesenchymal transition (EndMT), whereas dEV significantly induced EndMT by activating the transforming growth factor-β/Smad3 signaling pathway, which impaired the tube formation and invivo wound healing abilities of ECs. Interestingly, the treatment of dEV-internalized ECs with nEVs rescued the induced EndMT effects. Of note, the internalization of nEV into T2DM adipose tissue-derived MSC resulted in the production of an altered n-dEV, which inhibited EndMT and supported the survival of T2DM db/db mice from severe wounds. Taken together, our findings suggest the role of dEV in endothelial dysfunction and delayed wound healing in T2DM by the promotion of EndMT. Moreover, nEV treatment can be considered a promising candidate for cell-free therapy to protect ECs in T2DM.

Endothelial-to-Mesenchymal Transition in Cardiovascular Pathophysiology.

Under different pathophysiological conditions, endothelial cells lose endothelial phenotype and gain mesenchymal cell-like phenotype via a process known as endothelial-to-mesenchymal transition (EndMT). At the molecular level, endothelial cells lose the expression of endothelial cell-specific markers such as CD31/platelet-endothelial cell adhesion molecule, von Willebrand factor, and vascular-endothelial cadherin and gain the expression of mesenchymal cell markers such as α-smooth muscle actin, N-cadherin, vimentin, fibroblast specific protein-1, and collagens. EndMT is induced by numerous different pathways triggered and modulated by multiple different and often redundant mechanisms in a context-dependent manner depending on the pathophysiological status of the cell. EndMT plays an essential role in embryonic development, particularly in atrioventricular valve development; however, EndMT is also implicated in the pathogenesis of several genetically determined and acquired diseases, including malignant, cardiovascular, inflammatory, and fibrotic disorders. Among cardiovascular diseases, aberrant EndMT is reported in atherosclerosis, pulmonary hypertension, valvular disease, fibroelastosis, and cardiac fibrosis. Accordingly, understanding the mechanisms behind the cause and/or effect of EndMT to eventually target EndMT appears to be a promising strategy for treating aberrant EndMT-associated diseases. However, this approach is limited by a lack of precise functional and molecular pathways, causes and/or effects, and a lack of robust animal models and human data about EndMT in different diseases. Here, we review different mechanisms in EndMT and the role of EndMT in various cardiovascular diseases.

Endothelial-mesenchymal transition, ventricular remodeling after myocardial infarction, and research progress of Chinese medicine intervention

Ventricular remodeling after myocardial infarction(VRAMI) is a pathological phenomenon triggered by the abrupt occlusion of coronary arteries, leading to myocardial ischemia and hypoxia. This intricate process encompasses alterations in the dimensions, composition, and elasticity of the ventricular tissue and reflects pathophysiological reactions and self-repair after cardiomyocytes are damaged. The characteristic pathological manifestation of VRAMI is the presence of myocardial fibrosis(MF), wherein fibrotic cardiac tissue undergoes a loss of contractile and relaxation capacity, ultimately culminating in heart failure(HF) and significantly impacting the patient's prognosis. Endothelial-mesenchymal transition(EndMT) is a biological process in which endothelial cells, in response to diverse pathological stimuli such as ischemia and hypoxia in the embryonic development period, undergo morphological alterations and functional impairment, progressively acquiring mesenchymal cell properties and ultimately differentiating into mesenchymal cells. The ongoing advancement of the EndMT process will result in an excessive buildup of collagen, thereby inducing structural harm to the myocardium and exacerbating the processes of VRAMI and MF. Recent investigations have demonstrated the pivotal involvement of EndMT in the pathological advancement of VRAMI. Consequently, a targeted intervention aimed at effectively impeding VRAMI, safeguarding cardiac function, and potentially serving as a novel therapeutic target for the prevention and treatment of VRAMI. This article provides a comprehensive review of recent Chinese and international literature, focusing on the role and pathophysiological mechanisms of EndMT in VRAMI. Additionally, it discusses the research progress of innovative targeted interventions using both traditional Chinese and Western medicine, so as to offer new insights and a theoretical foundation for the clinical treatment of the disease.

BMP9 attenuates IL-33 signaling and prevents endothelial-to-mesenchymal transition in pulmonary arterial hypertension

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): Dutch Cardiovascular Alliance - PHAEDRA IMPACT Background Pulmonary Arterial hypertension (PAH) is a rare and progressive disease characterized by increased vascular resistance and remodeling of the pulmonary arteries. Disturbed Transforming growth factor (TGF)-β signaling, often associated with mutations in the gene encoding for the bone morphogenic protein receptor type II (BMPR2) and endothelial-to-mesenchymal transition (EndMT), emerges as a central culprit in the pathogenesis of PAH. Interleukin-33 (IL-33) has been identified as an inducer of EndMT, and its soluble receptor ST2 (sST2) has emerged as a potential biomarker for PAH. Bone morphogenic protein (BMP) 9, a BMPR2 ligand, showing a high affinity for endothelial cells, is being explored as a therapeutic approach. Purpose We hypothesize that a crosstalk between the TGF-β pathway and IL-33, a known promoter of vascular remodeling, occurs in PAH. This study aims to unravel the protective role of BMP9 in PAH, with a specific focus on the involvement of EndMT, a key player in the pathogenesis of vascular diseases. Methods The expression of IL-33 protein levels was assessed in Pulmonary Arterial Endothelial Cells (PAEC) and in lung tissues from experimentally induced PH (Sugen/Hypoxia (SuHx)) or control mice. Signal transduction and EndMT were investigated in PAECs exposed to IL-33, BMP9 and sST2, by gene expression analysis (qPCR), western blotting, ELISA and immunostaining. BMP9 and sST2 levels were measured in plasma from PAH patients by ELISA. Results Elevated IL-33 expression was observed in PAEC from PAH patients and lung tissues from SuHx mice compared to healthy controls. In vitro, BMP9 significantly induced the expression of the IL-33 soluble receptor ST2, while concurrently reducing IL-33 target gene expression. IL-33-induced EndoMT in PAEC was effectively mitigated by pre-incubation with BMP9, proving more efficacious than ST2 neutralizing antibody. Furthermore, a correlation between BMP9 and sST2 levels in plasma from PAH patients was identified. Conclusion Our findings demonstrate that BMP9 offers superior protections against IL-33-induced EndMT in PAECs compared to a ST2 neutralizing antibody. BMP9 induces expression of sST2, leading to IL-33 neutralization and subsequent EndMT inhibition. Therefore, targeting the IL-33 pathway in PAH patients presents a promising therapeutic option for preventing EndMT. This study provides novel insights into the pathogenesis of PAH, revealing a potential therapeutic target for this rare disease.BMP9 inhibits IL-33 downstream signalingBMP9 protects from IL-33-induced EndMT

Furin knockdown inhibited EndMT and abnormal proliferation and migration of endothelial cells.

In the pathogenesis of atherosclerotic cardiovascular disorders, vascular endothelium is crucial. A critical step in the development of atherosclerosis is endothelial dysfunction. Furin may play a factor in vascular remodeling, inflammatory cell infiltration, regulation of plaque stability, and atherosclerosis by affecting the adhesion and migration of endothelial cells. It is yet unknown, though, how furin contributes to endothelial dysfunction. We stimulated endothelial cells with oxidized modified lipoprotein (ox-LDL). Endothelial-to-mesenchymal transition (EndMT) was found using immunofluorescence (IF) and western blot (WB). Furin expression level and Hippo/YAP signal activation were found using reverse transcription-quantitative PCR (RT-qPCR) and WB, respectively. To achieve the goal of furin knockdown, we transfected siRNA using the RNA transmate reagent. Following furin knockdown, cell proliferation, and migration were assessed by the CCK-8, scratch assay, and transwell gold assay, respectively. WB and IF both picked up on EndMT. WB and RT-qPCR, respectively, were used to find furin's expression level. We chose the important micrornas that can regulate furin and we then confirmed them using RT-qPCR. EndMT was created by ox-LDL, evidenced by the up-regulation of mesenchymal cell markers and the down-regulation of endothelial cell markers. Furin expression levels in both protein and mRNA were increased, and the Hippo/YAP signaling pathway was turned on. Furin knockdown dramatically reduced the aberrant migration and proliferation of endothelial cells by ox-LDL stimulation. Furin knockdown can also suppress ox-LDL-induced EndMT, up-regulate indicators of endothelial cells, and down-regulate markers of mesenchymal cells. After ox-LDL stimulation and siRNA transfection, furin's expression level was up-regulated and down-regulated. Our study demonstrated that furin knockdown could affect ox-LDL-induced abnormal endothelial cell proliferation, migration, and EndMT. This implies that furin plays an important role in endothelial dysfunction.