Novel evaluation of pulmonary hypertension associated with chronic lung disease using perfusion SPECT/CT: A pilot study.

In pulmonary hypertension (PH) associated with chronic lung disease (CLD), identifying patients who would benefit from pulmonary vasodilators is a significant clinical challenge because the presence of PH is associated with poorer survival. This study evaluated the severity of pulmonary circulation impairment in patients with CLD-PH using pulmonary perfusion single-photon emission computed tomography/computed tomography (SPECT/CT). This single-center, observational study enrolled patients with CLD-PH who had a mean pulmonary arterial pressure (PAP) ≥ 25 mmHg, as confirmed by right heart catheterization. The primary outcome was to measure the percentage of pulmonary perfusion defect (%PPD), calculated by dividing the perfusion defect volume from perfusion SPECT images by the lung volume from CT scan images. The secondary outcome was to assess the correlation between %PPD and baseline characteristics. The median %PPD was 52.4% (interquartile range, 42.5%-72.3%) in 22 patients. In multivariate linear regression analysis, both forced vital capacity (ß = 0.58, p = 0.008) and mean PAP (ß = 0.68, p = 0.001) were significantly correlated with %PPD. In conclusion, significant correlation between mean PAP and %PPD in patients with CLD-PH was observed. This noninvasive assessment of %PPD may be useful for evaluating the severity of pulmonary circulation impairment in CLD-PH.

Endothelial specific LAT1 ablation normalizes tumor vasculature.

Some endothelial cells in the tumor vasculature expressed a system L amino acid transporter LAT1. To elucidate the role of LAT1 in tumor related endothelial cells, tumor cells were injected into endothelial specific LAT1 conditional knockout mice (Slc7a5flox/flox; Cdh5-Cre-ERT2) and found that the shape of the tumor vasculature was normalized and that the size and numbers of lung metastasis was reduced. TNFα-induced expression of VCAM1 and E-selectin at the surface of HUVEC, both of which are responsible for enhanced monocyte attachment and pre-metastatic niche formation, was reduced in the presence of LAT1 inhibitor, nanvuranlat. Deprivation of tryptophan, an LAT1 substrate, mimicked LAT1 inhibition, which led to activation of MEK1/2-ERK1/2 pathway and subsequent cystathionine γ lyase (CTH) induction. Increased production of hydrogen sulfide (H2S) by CTH was at least partially responsible for tumor vascular normalization, leading to decreased leakiness and enhanced delivery of chemotherapeutic agents to the tumor.

Macrophages play a crucial role in vascular smooth muscle cell coverage.

The microvascular system consists of two cell types: endothelial and mural (pericytes and vascular smooth muscle cells; VSMCs) cells. Communication between endothelial and mural cells plays a pivotal role in the maintenance of vascular homeostasis; however, in vivo molecular and cellular mechanisms underlying mural cell development remain unclear. In this study, we found that macrophages played a crucial role in TGFß-dependent pericyte-to-VSMC differentiation during retinal vasculature development. In mice with constitutively-active Foxo1-overexpression, substantial accumulation of TGFß1-producing macrophages and pericytes around the angiogenic front region was observed. Additionally, the TGFß-SMAD pathway was activated in pericytes adjacent to macrophages, resulting in an excess ectopic α-smooth muscle actin-positive VSMCs. Furthermore, we identified endothelial SEMA3C as an attractant for macrophages. In vivo neutralization of SEMA3C rescued macrophage accumulation and ectopic VSMC phenotypes in the mice, as well as drug-induced macrophage depletion. Therefore, macrophages play an important physiological role in VSMC development via the FOXO1-SEMA3C pathway.

Impact of polypharmacy on 3-year mortality in patients with heart failure: a retrospective study.

BACKGROUND: Guideline-directed medical therapy (GDMT) is important in heart failure management; however, polypharmacy itself may impact heart failure. Although measures against polypharmacy are needed, current discussion on unilateral drug tapering (including the drugs that should be tapered) is insufficient. In this study, we investigated the relationship between the number of prescribed GDMT drugs and prognosis in patients with heart failure. METHODS: In this single-centre retrospective study, 3,146 eligible patients with heart failure were included and divided into four groups based on the median number of prescribed GDMT drugs and the median number of drugs not included in the GDMT (ni-GDMT) at the time of hospital discharge. The definition of GDMT was based on various Japanese guidelines. The primary outcome was all-cause mortality within 3 years of hospital discharge. RESULTS: A total of 252 deaths were observed during the 3-year follow-up period. Kaplan-Meier analysis revealed that groups with GDMT drug count ≥ 5 and ni-GDMT drug count < 4 had the lowest mortality, and those with GDMT drug count < 5 and ni-GDMT drug count ≥ 4 had the highest mortality (log-rank, P < 0.001). Cox regression analysis revealed a significant association between ni-GDMT drug count and all-cause mortality, even after adjustment for number of GDMT medications, age, male, left ventricular ejection function < 40%, hemoglobin, albumin levels, and estimated glomerular filtration rate [HR = 1.06 (95% CI: 1.01-1.11), P = 0.020]. Conversely, the GDMT drug count was not associated with increased mortality rates. CONCLUSIONS: The ni-GDMT drug count was significantly associated with 3-year mortality in patients with heart failure. Conversely, the GDMT drug count did not worsen the prognosis. Polypharmacy measures should consider ni-GDMT drug quantity to improve the prognosis and outcomes in patients with heart failure.

Proposed Clinical Algorithm for Pleuroparenchymal Fibroelastosis (PPFE).

Pleuroparenchymal fibroelastosis (PPFE) is characterized by fibrosis involving the pleura and subpleural lung parenchyma, predominantly in the upper lobes. As PPFE appears to occur in patients with heterogeneous etiologies, the disease course is thus also heterogenous, with some patients showing rapid progression while others have slow progression. Therefore, it is very difficult to predict prognosis with PPFE. Needless to say, this problematic matter has influenced the treatment strategy of PPFE patients. In fact, until now no evidence has been shown for use in creating an appropriate management algorithm for PPFE. We speculate that "uncoordinated breathing" is the most important reason for dyspnea in PPFE patients. Because monitoring of physique and not just pulmonary function and radiological evaluation is also very important, particularly in PPFE patients, this review focused on the characteristics of PPFE through an overview of previous studies in this field, and we proposed an algorithm as precision medicine based on the current evidence. Multiple views by the pulmonologist are needed to standardize a clinical algorithm that is necessary to correctly assess PPFE patients under the premise of maintenance of physique by providing appropriate nutritional care and pulmonary rehabilitation.

Vaccine Therapy for Heart Failure Targeting the Inflammatory Cytokine Igfbp7.

BACKGROUND: The heart comprises many types of cells such as cardiomyocytes, endothelial cells (ECs), fibroblasts, smooth muscle cells, pericytes, and blood cells. Every cell type responds to various stressors (eg, hemodynamic overload and ischemia) and changes its properties and interrelationships among cells. To date, heart failure research has focused mainly on cardiomyocytes; however, other types of cells and their cell-to-cell interactions might also be important in the pathogenesis of heart failure. METHODS: Pressure overload was imposed on mice by transverse aortic constriction and the vascular structure of the heart was examined using a tissue transparency technique. Functional and molecular analyses including single-cell RNA sequencing were performed on the hearts of wild-type mice and EC-specific gene knockout mice. Metabolites in heart tissue were measured by capillary electrophoresis-time of flight-mass spectrometry system. The vaccine was prepared by conjugating the synthesized epitope peptides with keyhole limpet hemocyanin and administered to mice with aluminum hydroxide as an adjuvant. Tissue samples from heart failure patients were used for single-nucleus RNA sequencing to examine gene expression in ECs and perform pathway analysis in cardiomyocytes. RESULTS: Pressure overload induced the development of intricately entwined blood vessels in murine hearts, leading to the accumulation of replication stress and DNA damage in cardiac ECs. Inhibition of cell proliferation by a cyclin-dependent kinase inhibitor reduced DNA damage in ECs and ameliorated transverse aortic constriction-induced cardiac dysfunction. Single-cell RNA sequencing analysis revealed upregulation of Igfbp7 (insulin-like growth factor-binding protein 7) expression in the senescent ECs and downregulation of insulin signaling and oxidative phosphorylation in cardiomyocytes of murine and human failing hearts. Overexpression of Igfbp7 in the murine heart using AAV9 (adeno-associated virus serotype 9) exacerbated cardiac dysfunction, while EC-specific deletion of Igfbp7 and the vaccine targeting Igfbp7 ameliorated cardiac dysfunction with increased oxidative phosphorylation in cardiomyocytes under pressure overload. CONCLUSIONS: Igfbp7 produced by senescent ECs causes cardiac dysfunction and vaccine therapy targeting Igfbp7 may be useful to prevent the development of heart failure.

Circulating KLRG1+ long-lived effector memory T cells retain the flexibility to become tissue resident.

KLRG1+ CD8 T cells persist for months after clearance of acute infections and maintain high levels of effector molecules, contributing protective immunity against systemic pathogens. Upon secondary infection, these long-lived effector cells (LLECs) are incapable of forming other circulating KLRG1- memory subsets such as central and effector memory T cells. Thus, KLRG1+ memory T cells are frequently referred to as a terminally differentiated population that is relatively short lived. Here, we show that after viral infection of mice, effector cells derived from LLECs rapidly enter nonlymphoid tissues and reduce pathogen burden but are largely dependent on receiving antigen cues from vascular endothelial cells. Single-cell RNA sequencing reveals that secondary memory cells in nonlymphoid tissues arising from either KLRG1+ or KLRG1- memory precursors develop a similar resident memory transcriptional signature. Thus, although LLECs cannot differentiate into other circulating memory populations, they still retain the flexibility to enter tissues and establish residency.

Hepatic function markers as prognostic factors in patients with acute kidney injury undergoing continuous renal replacement therapy.

Acute kidney injury (AKI) requiring continuous renal replacement therapy (CRRT), secondary to cardiovascular disease and sepsis, is associated with high in-hospital mortality. Although studies have examined cardiovascular disease and sepsis in AKI, the association between AKI and hepatic functional impairment remains unclear. We hypothesized that hepatic function markers would predict mortality in patients undergoing CRRT. We included 1,899 CRRT patients from a multi-centre database. In Phase 1, participants were classified according to the total bilirubin (T-Bil) levels on the day of, and 3 days after, CRRT initiation: T-Bil < 1.2, 1.2 ≤ T-Bil < 2, and T-Bil ≥ 2 mg/dL. In Phase 2, propensity score matching (PSM) was performed to examine the effect of a T-Bil cutoff of 1.2 mg/dL (supported by the Sequential Organ Failure Assessment score); creating two groups based on a T-Bil cutoff of 1.2 mg/dL 3 days after CRRT initiation. The primary endpoint was total mortality 90 days after CRRT initiation, which was 34.7% (n = 571). In Phase 1, the T-Bil, aspartate transaminase (AST), alanine transaminase (ALT), and AST/ALT (De Ritis ratio) levels at CRRT initiation were not associated with the prognosis, while T-Bil, AST, and the De Ritis ratio 3 days after CRRT initiation were independent factors. In Phase 2, T-Bil ≥1.2 mg/dL on day 3 was a significant independent prognostic factor, even after PSM [hazard ratio: 2.41 (95% CI; 1.84-3.17), p < 0.001]. T-Bil ≥1.2 mg/dL 3 days after CRRT initiation predicted 90-day mortality. Changes in hepatic function markers in acute renal failure may enable stratification of high-risk patients.

Prognostic impact of plasma volume status during hospital admission in patients with acute decompensated heart failure.

AIMS: Plasma volume status (PVS), a measure of plasma volume, has been evaluated as a prognostic marker for chronic heart failure. Although the prognostic value of PVS has been reported, its significance in patients with acute decompensated heart failure (ADHF) admitted to the cardiovascular intensive care unit (CICU) remains unclear. In this study, we examined the relationship between PVS and long-term mortality in patients with ADHF admitted to the CICU. METHODS: Between January 2018 and December 2020, 363 consecutive patients with ADHF were admitted to the Nippon Medical School Hospital CICU. Of the 363 patients, 206 (mean age, 74.9 ± 12.9 years; men, 64.6%) were enrolled in this study. Patients who received red blood cell transfusions, underwent dialysis, were discharged from the CICU or died in the hospital were excluded from the study. We measured the PVS of the patients at admission, transfer to the general ward (GW) and discharge using the Kaplan-Hakim formula. The patients were assigned to four groups according to the quartiles of their PVS measured at each of the three abovementioned timepoints. We examined the association between PVS and all-cause mortality during the observation period (1134 days). The primary endpoint of this study was all-cause mortality. RESULTS: The Kaplan-Meier analysis showed that the high PVS group had a significantly higher mortality rate at admission, transfer to the GW and discharge than the other groups (log-rank test: P = 0.016, P = 0.005 and P < 0.001, respectively). Univariate Cox regression analysis showed that age, body mass index, history of heart failure, use of beta-blockers, albumin level, blood urea nitrogen level, N-terminal pro-brain natriuretic peptide level and left ventricular ejection fraction were significantly different among the PVS groups and thus were not significant prognostic factors for ADHF. Furthermore, the multivariate analysis revealed that PVS at discharge [hazard ratio (HR) = 1.06 (1.00-1.12), P = 0.048] was an independent poor prognostic factor for ADHF. CONCLUSIONS: This study highlights the effect of PVS measured at different timepoints on the prognoses of ADHF patients. Regular assessment of PVS, particularly at discharge, is crucial for optimising patient management and achieving favourable outcomes in cases of ADHF.

Reinforcement of pimobendan with guideline-directed medical therapy may reduce the rehospitalization rates in patients with heart failure: retrospective cohort study.

BACKGROUND: Pimobendan reportedly improves the subjective symptoms of heart failure. However, evidence of improved prognosis is lacking. This study aimed to determine whether reinforcing guideline-directed medical therapy (GDMT) improved rehospitalization rates for worsening heart failure in patients administered pimobendan. METHODS: A total of 175 patients with heart failure who were urgently admitted to our hospital for worsening heart failure and who received pimobendan between January 2015 and February 2022 were included. Of the 175 patients, 44 were excluded because of in-hospital death at the time of pimobendan induction. The remaining 131 patients were divided into two groups, the reduced ejection fraction (rEF) (n = 93) and non-rEF (n = 38) groups, and further divided into the GDMT-reinforced and non-reinforced groups. RESULTS: In patients with rEF, the rate of rehospitalization for heart failure was significantly lower in the GDMT-reinforced group than in the non-reinforced group (log-rank test, P = .04). However, the same trend was not observed in the non-rEF group. CONCLUSIONS: Reinforcing GDMT may reduce the heart failure rehospitalization rate in patients with pimobendan administration and rEF. However, multicenter collaborative research is needed. TRIAL REGISTRATION: IRB Approval by the Nippon Medical School Hospital Ethics Committee B-2021-433 (April 10, 2023).

Predicting heart failure symptoms from the apnoea-hypopnoea index determined by full- night polysomnography.

AIMS: Sleep-disordered breathing (SDB) is closely related to cardiovascular diseases. The higher the apnoea-hypopnoea index (AHI), the higher the prevalence of cardiovascular diseases. Despite these findings suggesting a close link between SDB and heart failure, the relationship between the severity of SDB and the onset of heart failure symptoms in individuals without apparent heart failure symptoms (Heart Failure Stage A + B) remains poorly understood. METHODS AND RESULTS: Between December 2010 and June 2017, we conducted full-night polysomnography (PSG) at the Nippon Medical School Chiba Hokusoh Hospital, extracting patients who were at risk of heart failure (Stage A or B in the Heart Failure Guidelines). Using a median cut-off of AHI ≥ 41.6 events/hour, we divided the patients into two groups and examined the composite endpoint of all-cause mortality plus hospitalization due to heart failure as the primary endpoint. We included 230 patients (mean age 63.0 ± 12.5 years, 78.3% males) meeting the selection criteria. When comparing the two groups, those with AHI < 41.6 events/hour (L group, n = 115) and those with AHI ≥ 41.6 events/hour (H group, n = 115), the H group had higher body mass index and higher serum triglyceride, and lower the frequency of acute coronary syndrome and lower estimated glomerular filtration rate than did the L group, but no other patient characteristics differed significantly. The H group had a significantly higher incidence of the composite endpoint than did the L group (10.6% vs. 2.6%, P = 0.027). Factors associated with the composite endpoint were identified through multivariate analyses, with AHI, haemoglobin, and left atrial dimension emerging as significant factors (hazard ratio [HR] = 1.02, 95% confidence interval [CI] = 1.00-1.04, P = 0.024; HR = 0.71, 95% CI = 0.54-0.94, P = 0.017; and HR = 1.10, 95% CI = 1.03-1.18, P = 0.006, respectively). Conversely, the minimum SpO2 during PSG (<80%) was not associated with the composite endpoint. CONCLUSIONS: In patients with SDB who are at risk of heart failure, severe SDB is associated with a high risk of all-cause mortality and the development of heart failure. Additionally, combining cardiac echocardiography and PSG data may improve risk stratification, offering potential assistance for early intervention. Further examination with a validation cohort is necessary.

IL-6/gp130 signaling in CD4+ T cells drives the pathogenesis of pulmonary hypertension.

Pulmonary arterial hypertension (PAH) is characterized by stenosis and occlusions of small pulmonary arteries, leading to elevated pulmonary arterial pressure and right heart failure. Although accumulating evidence shows the importance of interleukin (IL)-6 in the pathogenesis of PAH, the target cells of IL-6 are poorly understood. Using mice harboring the floxed allele of gp130, a subunit of the IL-6 receptor, we found substantial Cre recombination in all hematopoietic cell lineages from the primitive hematopoietic stem cell level in SM22α-Cre mice. We also revealed that a CD4+ cell-specific gp130 deletion ameliorated the phenotype of hypoxia-induced pulmonary hypertension in mice. Disruption of IL-6 signaling via deletion of gp130 in CD4+ T cells inhibited phosphorylation of signal transducer and activator of transcription 3 (STAT3) and suppressed the hypoxia-induced increase in T helper 17 cells. To further examine the role of IL-6/gp130 signaling in more severe PH models, we developed Il6 knockout (KO) rats using the CRISPR/Cas9 system and showed that IL-6 deficiency could improve the pathophysiology in hypoxia-, monocrotaline-, and Sugen5416/hypoxia (SuHx)-induced rat PH models. Phosphorylation of STAT3 in CD4+ cells was also observed around the vascular lesions in the lungs of the SuHx rat model, but not in Il6 KO rats. Blockade of IL-6 signaling had an additive effect on conventional PAH therapeutics, such as endothelin receptor antagonist (macitentan) and soluble guanylyl cyclase stimulator (BAY41-2272). These findings suggest that IL-6/gp130 signaling in CD4+ cells plays a critical role in the pathogenesis of PAH.

Fractional excretion of urea nitrogen can identify true worsening renal function in patients with heart failure.

AIMS: Fractional excretion of urea nitrogen (FEUN), used to differentiate the cause of acute kidney injury, has emerged as a useful fluid index in patients with heart failure (HF). We hypothesized that FEUN could be useful in identifying worsening renal function (WRF) associated with poor outcomes in patients with acute HF (AHF). METHODS AND RESULTS: Overall, 1103 patients with AHF (median age, 78 years; male proportion, 60%) were categorized into six groups according to the presence of WRF and FEUN values (low, ≤32.1%; medium, >32.1% and ≤38.0%; and high, >38.0%) at discharge. WRF was defined as an increase of ≥0.3 mg/dL in the serum creatinine level from admission to discharge. FEUN was calculated by the following formula: (urinary urea × serum creatinine) × 100/(serum urea × urinary creatinine). The cut-off values for low, medium, and high FEUN were based on a previous study. The primary outcome of this study was HF readmission after hospital discharge. During the 1 year follow-up, 170 HF readmissions occurred. Kaplan-Meier analysis revealed significantly higher HF readmission rates in patients with WRF than in those without WRF (log-rank test, P < 0.001). Additionally, among patients with WRF, HF readmission rates were lowest in those with medium FEUN values, followed by those with low FEUN values and those with high FEUN values. On multivariable analysis, the presence of WRF with low or high FEUN values was independently associated with increased HF readmission, as compared with the absence of WRF with medium FEUN values. Notably, no association was noted between WRF with medium FEUN values and HF readmission. CONCLUSIONS: The prognostic impact of WRF was significantly mediated by the FEUN values and was associated with worse outcomes only when the FEUN values were either low or high. Our study suggests that FEUN can identify prognostically relevant WRF in patients with AHF.

Endothelial cells regulate alveolar morphogenesis by constructing basement membranes acting as a scaffold for myofibroblasts.

Alveologenesis is a spatially coordinated morphogenetic event, during which alveolar myofibroblasts surround the terminal sacs constructed by epithelial cells and endothelial cells (ECs), then contract to form secondary septa to generate alveoli in the lungs. Recent studies have demonstrated the important role of alveolar ECs in this morphogenetic event. However, the mechanisms underlying EC-mediated alveologenesis remain unknown. Herein, we show that ECs regulate alveologenesis by constructing basement membranes (BMs) acting as a scaffold for myofibroblasts to induce septa formation through activating mechanical signaling. Rap1, a small GTPase of the Ras superfamily, is known to stimulate integrin-mediated cell adhesions. EC-specific Rap1-deficient (Rap1iECKO) mice exhibit impaired septa formation and hypo-alveolarization due to the decreased mechanical signaling in myofibroblasts. In Rap1iECKO mice, ECs fail to stimulate integrin ß1 to recruit Collagen type IV (Col-4) into BMs required for myofibroblast-mediated septa formation. Consistently, EC-specific integrin ß1-deficient mice show hypo-alveolarization, defective mechanical signaling in myofibroblasts, and disorganized BMs. These data demonstrate that alveolar ECs promote integrin ß1-mediated Col-4 recruitment in a Rap1-dependent manner, thereby constructing BMs acting as a scaffold for myofibroblasts to induce mechanical signal-mediated alveologenesis. Thus, this study unveils a mechanism of organ morphogenesis mediated by ECs through intrinsic functions.

Impact of Red Blood Cell Transfusion on Subsequent Cardiovascular Events in Patients with Acute Heart Failure and Anemia.

Red blood cell (RBC) transfusion therapy is often performed in patients with acute heart failure (AHF) and anemia; however, its impact on subsequent cardiovascular events is unclear. We examined whether RBC transfusion influences major adverse cardiovascular events (MACE) after discharge in patients with AHF and anemia.We classified patients with AHF and anemia (nadir hemoglobin level < 10 g/dL) according to whether they received RBC transfusion during hospitalization. The endpoint was MACE (composite of all-cause death, non-fatal acute coronary syndrome/stroke, or heart failure readmission) 180 days after discharge. For survival analysis, we used propensity score matching analysis with the log-rank test. As sensitivity analysis, we performed inverse probability weighting analysis and multivariable Cox regression analysis.Among 448 patients with AHF and anemia (median age, 81 years; male, 55%), 155 received RBC transfusion and 293 did not. The transfused patients had worse clinical features than the non-transfused patients, with lower levels of nadir hemoglobin and serum albumin and a lower estimated glomerular filtration rate. In the propensity-matched cohort of 87 pairs, there was no significant difference in the MACE-free survival rate between the 2 groups (transfused, 73.8% vs. non-transfused, 65.3%; P = 0.317). This result was consistent in the inverse probability weighting analysis (transfused, 76.0% vs. non-transfused, 68.7%; P = 0.512), and RBC transfusion was not significantly associated with post-discharge MACE in the multivariable Cox regression analysis (adjusted hazard ratio: 1.468, 95% confidence interval: 0.976-2.207; P = 0.065).In conclusion, this study suggests that RBC transfusions for anemia may not improve clinical outcomes in patients with AHF.

The efficacy and safety of ivabradine hydrochloride in hemodialysis patients with chronic heart failure.

INTRODUCTION: There is little evidence for ivabradine hydrochloride in patients undergoing hemodialysis. METHODS: In this open-label prospective interventional trial of hemodialysis patients with chronic heart failure, during 12 weeks of treatment, changes in Heart rate (HR), frequency of dialysis-related hypotension were examined, and we investigated health-related quality of life (HR-QOL) and adverse effects. RESULTS: 18 patients from 6 facilities were enrolled in the study. HR significantly decreased over time, from 87 ± 12.61/min at baseline to 75.85 ± 8.91/min (p = 0.0003), and systolic blood pressure also increased significantly (p < 0.0001). The frequency of dialysis-related hypotension was markedly reduced (p = 0.0001). The HR-QOL survey showed significant improvements in Social Functioning among others (p = 0.0178). No specific adverse events occurred. CONCLUSION: Ivabradine hydrochloride improved dialysis-related hypotension. Furthermore, the HR-QOL improvement effect were suggested. These results demonstrated the safety and effectiveness of ivabradine hydrochloride.

CD40 is expressed in the subsets of endothelial cells undergoing partial endothelial-mesenchymal transition in tumor microenvironment.

Tumor progression and metastasis are regulated by endothelial cells undergoing endothelial-mesenchymal transition (EndoMT), a cellular differentiation process in which endothelial cells lose their properties and differentiate into mesenchymal cells. The cells undergoing EndoMT differentiate through a spectrum of intermediate phases, suggesting that some cells remain in a partial EndoMT state and exhibit an endothelial/mesenchymal phenotype. However, detailed analysis of partial EndoMT has been hampered by the lack of specific markers. Transforming growth factor-ß (TGF-ß) plays a central role in the induction of EndoMT. Here, we showed that inhibition of TGF-ß signaling suppressed EndoMT in a human oral cancer cell xenograft mouse model. By using genetic labeling of endothelial cell lineage, we also established a novel EndoMT reporter cell system, the EndoMT reporter endothelial cells (EMRECs), which allow visualization of sequential changes during TGF-ß-induced EndoMT. Using EMRECs, we characterized the gene profiles of multiple EndoMT stages and identified CD40 as a novel partial EndoMT-specific marker. CD40 expression was upregulated in the cells undergoing partial EndoMT, but decreased in the full EndoMT cells. Furthermore, single-cell RNA sequencing analysis of human tumors revealed that CD40 expression was enriched in the population of cells expressing both endothelial and mesenchymal cell markers. Moreover, decreased expression of CD40 in EMRECs enhanced TGF-ß-induced EndoMT, suggesting that CD40 expressed during partial EndoMT inhibits transition to full EndoMT. The present findings provide a better understanding of the mechanisms underlying TGF-ß-induced EndoMT and will facilitate the development of novel therapeutic strategies targeting EndoMT-driven cancer progression and metastasis.

Impact of proteinuria on long-term prognosis in patients with coronary artery disease.

BACKGROUND: This study aimed to investigate the association between proteinuria and long-term prognosis in patients with coronary artery disease. METHODS: This was a single-center observational study. A total of 1351 patients were identified who underwent percutaneous coronary intervention, and whose urine data were available. Patients were divided into two groups according to the presence (n = 245) or absence (n = 1106) of proteinuria. All-cause and cardiovascular deaths were primarily evaluated. RESULTS: The prevalence rates of hypertension and diabetes were significantly higher, and the baseline estimated glomerular filtration rate (eGFR) was lower in patients with proteinuria than in those without proteinuria. During the median follow-up of 4.1 years (interquartile range, 1.7-6.8 years), the occurrences of all-cause and cardiovascular deaths were significantly higher in patients with proteinuria. Multivariable Cox regression analysis indicated that the presence of proteinuria was a significant predictor of cardiovascular death as well as age, BMI, reduced eGFR, and left ventricular ejection fraction. When stratified into four groups based on eGFR category (eGFR <60 or ≥60 ml/min/1.73 m2) and absence or presence of proteinuria, the incidence rates of all-cause and cardiovascular deaths were highest in patients with proteinuria and eGFR less than 60 ml/min/1.73 m2. Furthermore, the incidence rates of all-cause and cardiovascular deaths were significantly higher in patients with proteinuria among both diabetic and nondiabetic patients. CONCLUSION: Proteinuria is associated with the long-term prognosis, and all-cause and cardiovascular deaths in patients with coronary artery disease, regardless of eGFR and the presence or absence of diabetes mellitus.

Rap1 small GTPase is essential for maintaining pulmonary endothelial barrier function in mice.

Vascular permeability is dynamically but tightly controlled by vascular endothelial (VE)-cadherin-mediated endothelial cell-cell junctions to maintain homeostasis. Thus, impairments of VE-cadherin-mediated cell adhesions lead to hyperpermeability, promoting the development and progression of various disease processes. Notably, the lungs are a highly vulnerable organ wherein pulmonary inflammation and infection result in vascular leakage. Herein, we showed that Rap1, a small GTPase, plays an essential role for maintaining pulmonary endothelial barrier function in mice. Endothelial cell-specific Rap1a/Rap1b double knockout mice exhibited severe pulmonary edema. They also showed vascular leakage in the hearts, but not in the brains. En face analyses of the pulmonary arteries and 3D-immunofluorescence analyses of the lungs revealed that Rap1 potentiates VE-cadherin-mediated endothelial cell-cell junctions through dynamic actin cytoskeleton reorganization. Rap1 inhibits formation of cytoplasmic actin bundles perpendicularly binding VE-cadherin adhesions through inhibition of a Rho-ROCK pathway-induced activation of cytoplasmic nonmuscle myosin II (NM-II). Simultaneously, Rap1 induces junctional NM-II activation to create circumferential actin bundles, which anchor and stabilize VE-cadherin at cell-cell junctions. We also showed that the mice carrying only one allele of either Rap1a or Rap1b out of the two Rap1 genes are more vulnerable to lipopolysaccharide (LPS)-induced pulmonary vascular leakage than wild-type mice, while activation of Rap1 by administration of 007, an activator for Epac, attenuates LPS-induced increase in pulmonary endothelial permeability in wild-type mice. Thus, we demonstrate that Rap1 plays an essential role for maintaining pulmonary endothelial barrier functions under physiological conditions and provides protection against inflammation-induced pulmonary vascular leakage.

Spatial heterogeneity of bone marrow endothelial cells unveils a distinct subtype in the epiphysis.

Bone marrow endothelial cells (BMECs) play a key role in bone formation and haematopoiesis. Although recent studies uncovered the cellular taxonomy of stromal compartments in the bone marrow (BM), the complexity of BMECs is not fully characterized. In the present study, using single-cell RNA sequencing, we defined a spatial heterogeneity of BMECs and identified a capillary subtype, termed type S (secondary ossification) endothelial cells (ECs), exclusively existing in the epiphysis. Type S ECs possessed unique phenotypic characteristics in terms of structure, plasticity and gene expression profiles. Genetic experiments showed that type S ECs atypically contributed to the acquisition of bone strength by secreting type I collagen, the most abundant bone matrix component. Moreover, these cells formed a distinct reservoir for haematopoietic stem cells. These findings provide the landscape for the cellular architecture in the BM vasculature and underscore the importance of epiphyseal ECs during bone and haematopoietic development.