Important Role of Endogenous Nerve Growth Factor Receptor in the Pathogenesis of Hypoxia-Induced Pulmonary Hypertension in Mice.

Pulmonary arterial hypertension (PAH) remains a disease with poor prognosis; thus, a new mechanism for PAH treatment is necessary. Circulating nerve growth factor receptor (Ngfr)-positive cells in peripheral blood mononuclear cells are associated with disease severity and the prognosis of PAH patients; however, the role of Ngfr in PAH is unknown. In this study, we evaluated the function of Ngfr using Ngfr gene-deletion (Ngfr-/-) mice. To elucidate the role of Ngfr in pulmonary hypertension (PH), we used Ngfr-/- mice that were exposed to chronic hypoxic conditions (10% O2) for 3 weeks. The development of hypoxia-induced PH was accelerated in Ngfr-/- mice compared to littermate controls. In contrast, the reconstitution of bone marrow (BM) in Ngfr-/- mice transplanted with wild-type BM cells improved PH. Notably, the exacerbation of PH in Ngfr-/- mice was accompanied by the upregulation of pulmonary vascular remodeling-related genes in lung tissue. In a hypoxia-induced PH model, Ngfr gene deletion resulted in PH exacerbation. This suggests that Ngfr may be a key molecule involved in the pathogenesis of PAH.

Effect of pulmonary vein isolation on the relationship between left atrial reverse remodeling and sympathetic nerve activity in patients with atrial fibrillation.

PURPOSE: Catheter ablation (CA) to isolate the pulmonary vein, which is an established treatment for atrial fibrillation (AF), is associated with left atrium reverse remodeling (LARR). The intrinsic cardiac autonomic nervous system includes the ganglion plexi adjacent to the pulmonary vein in the left atrium (LA). However, little is known about the effect of CA on the relationship between LARR and sympathetic nerve activity in patients with AF. METHODS: This study enrolled 22 AF patients with a normal left ventricular ejection fraction (LVEF) aged 64.6 ± 12.9 years who were scheduled for CA. Sympathetic nerve activity was evaluated by direct recording of muscle sympathetic nerve activity (MSNA) before and 12 weeks after CA. Blood pressure, heart rate (HR), HR variability, and echocardiography were also measured. RESULTS: The heart rate increased significantly after CA (63 ± 10.9 vs. 70.6 ± 7.7 beats/min, p < 0.01), but blood pressure did not change. A high frequency (HF) and low frequency (LF) of HR variability decreased significantly after ablation, but no significant change in LF/HF was observed. CA significantly decreased MSNA (38.9 ± 9.9 vs. 28 ± 9.1 bursts/min, p < 0.01). Moreover, regression analysis revealed a positive correlation between the percentage change in MSNA and the LA volume index (r = 0.442, p < 0.05). CONCLUSIONS: Our results show that CA for AF reduced MSNA and the decrease was associated with the LA volume index in AF patients with a normal LVEF. These findings suggest that LARR induced by CA for AF decrease sympathetic nerve activity.

Diabetes impairs the angiogenic capacity of human adipose-derived stem cells by reducing the CD271+ subpopulation in adipose tissue.

Type 2 diabetes mellitus is an important risk factor for cardiovascular diseases (CVDs). Therapeutic angiogenesis using adipose-derived stem cells (ADSCs) is attractive for CVD therapy. However, although it would be critical for ADSC application on CVD therapy, whether and how diabetes impairs human ADSC therapeutic potential is still uncertain. In this study, we aimed to investigate the impact of diabetes on the angiogenic potential of ADSCs in patients with CVDs, with special focus on stemness-related genes and cellular alteration of ADSCs. We established cultured ADSCs from diabetic (DM-ADSCs) and non-diabetic patients (nonDM-ADSCs) with CVDs. DM-ADSCs demonstrated limited proliferative capacity and reduced paracrine capacity of VEGF, with lower expression of the stemness gene SOX2. Angiogenic capacity and ADSC engraftment were assessed using xenograft experiments in a hindlimb ischemia model of athymic nude mice. Consistent with the results of in vitro assays, DM-ADSCs did not rescue limb ischemia. In contrast, nonDM-ADSCs induced neovascularization with enhanced engraftment. To elucidate the mechanism underlying these ADSC changes, we compared the surface marker profiles of freshly isolated ADSCs obtained from diabetic and non-diabetic patients by flow cytometry. Among studied subsets, the CD34+CD31-CD271+ subpopulation was reduced in the adipose tissues of diabetic patients. In addition, SOX2 expression and proliferative capacity were considerably reduced in nonDM-ADSCs derived from the stromal vascular fraction (SVF) with depletion of CD271+ cells (p < 0.01). Our observations elucidated that reduced CD271+ subpopulation is critical for the impairment of ADSCs in diabetic patients. Further investigations on the CD271+ subset of ADSCs might provide novel insights into the mechanisms and solutions for diabetes-related ADSC dysfunction in cell therapy.

Sphigosine-1-phosphate receptor 1 promotes neointimal hyperplasia in a mouse model of carotid artery injury.

Vascular remodeling, resulting from proliferation and migration of vascular smooth muscle cells (VSMCs), is a major cause of atherosclerosis and restenosis. The lysophospholipid mediator sphingosine-1-phosphate (S1P) regulates proliferation and migration of VSMCs via S1P-specific G protein-coupled receptors, including S1P receptor 1 (S1PR1) to S1PR3. However, the role of S1PR1 in vascular remodeling is not well understood. Therefore, in this study, we aimed to investigate the effect of S1PR1 on neointimal hyperplasia in a carotid artery ligation mouse model using transgenic C57Bl/6 mice that overexpressed S1PR1 (Tg-S1PR1) under the control of α-smooth muscle actin promoter. We found that S1PR1 expression in carotid artery was upregulated after carotid artery ligation in non-transgenic (nTg) mice. Tg-S1PR1 mice showed enhanced ligation-induced neointimal hyperplasia with increased neointimal cell proliferation, compared with control nTg mice. VSMCs isolated from Tg-S1PR1 mice showed enhanced proliferation and migration in response to S1P stimulation. VSMCs from Tg-S1PR1 mice showed greater expression of interleukin-6 (IL-6) compared with nTg mouse-derived VSMCs, and administration of IL-6-neutralizing antibody into Tg-S1PR1 mice suppressed neointimal hyperplasia. These results suggest that S1P-S1PR1 signaling plays an important role in neointimal hyperplasia after vascular injury via IL-6 production.

Occult constrictive pericardial disease emerging 40 years after chest radiation therapy: a case report.

BACKGROUND: The main etiology of constrictive pericarditis (CP) has changed from tuberculosis to therapeutic mediastinal radiation and cardiac surgery. Occult constrictive pericardial disease (OCPD) is a covert disease in which CP is manifested in a condition of volume overload. CASE PRESENTATION: A 60-year-old patient with a history of thoracic radiation therapy for non-Hodgkin's lymphoma (40 years earlier) was transferred to our hospital for treatment of repeated congestive heart failure. For a preoperative hemodynamic study, pre-hydration with intravenous normal saline (50 mL/hour) was used to manifest the pericardial disease and prevent contrast-induced nephropathy. The hemodynamic study showed a right ventricular dip-plateau pattern and discordance of right and left ventricular systolic pressures during inspiration, which was not seen in the volume-controlled state. These responses were concordant with OCPD. A pericardiectomy, aortic valve replacement, and mitral and tricuspid valve repair were performed. Postoperatively, the heart failure was controlled with standard medication. CONCLUSIONS: This case revealed a volume-induced change in hemodynamics in OCPD with severe combined valvular heart disease, which suggests the importance of considering OCPD in patients who had undergone radiation therapy 40 years before.

Effects of medical therapy and age on cardiac output changes following balloon pulmonary angioplasty: Implications for combination therapy in chronic thromboembolic pulmonary hypertension.

BACKGROUND: Some patients with chronic thromboembolic pulmonary hypertension (CTEPH) exhibit exercise intolerance due to reduced cardiac output (CO) even after successful balloon pulmonary angioplasty (BPA). Medical therapy is a potential option for such cases; however, it is unclear which patients necessitate it even after BPA. METHODS: This study included 286 patients with CTEPH who underwent BPA and right heart catheterization 1 year after the final BPA and classified them into no-medication and withdrawal groups. The no-medication group comprised patients without pulmonary hypertension (PH) medications before and after BPA, while the withdrawal group included patients who received PH medications before BPA and discontinued them after BPA. We assessed differences in the changes in CO after BPA from baseline (ΔCO) between the 2 groups. Additionally, we evaluated the ΔCO among different age categories within each group: younger (<60 years), middle-aged (60-70 years), and older adults (≥70 years). RESULTS: After adjusting baseline covariates, overall CO did not differ significantly. However, ΔCO was significantly positive in the no-medication group but negative in the withdrawal group (0.32 and -0.33, difference in ΔCO: -0.65, 95% confidence intervals: -0.90 to -0.40). A significantly positive effect on ΔCO was observed in younger and middle-aged individuals, with a significant interaction between age and ΔCO in no-medication groups. CONCLUSIONS: Increasing CO with BPA alone may be challenging with age in patients with CTEPH. Given that discontinuation of PH medication after BPA decreased CO more than the effect of BPA, medical therapy might be necessary even after successful BPA.

Single cell transcriptomics identifies adipose tissue CD271+ progenitors for enhanced angiogenesis in limb ischemia.

Therapeutic angiogenesis using mesenchymal stem/stromal cell grafts have shown modest and controversial effects in preventing amputation for patients with critical limb ischemia. Through single-cell transcriptomic analysis of human tissues, we identified CD271 + progenitors specifically from subcutaneous adipose tissue (AT) as having the most prominent pro-angiogenic gene profile distinct from other stem cell populations. AT-CD271 + progenitors demonstrated robust in vivo angiogenic capacity, over conventional adipose stromal cell grafts, characterized by long-term engraftment, augmented tissue regeneration, and significant recovery of blood flow in a xenograft model of limb ischemia. Mechanistically, the angiogenic capacity of CD271 + progenitors is dependent on functional CD271 and mTOR signaling. Notably, the number and angiogenic capacity of CD271 + progenitors was strikingly reduced in insulin resistant donors. Our study highlights the identification of AT-CD271 + progenitors with in vivo superior efficacy for limb ischemia. Furthermore, we showcase comprehensive single-cell transcriptomics strategies for identification of suitable grafts for cell therapy. HIGHLIGHTS: Adipose tissue stromal cells have a distinct angiogenic gene profile among human cell sources. CD271 + progenitors in adipose tissue have a prominent angiogenic gene profile. CD271 + progenitors show superior therapeutic capacities for limb ischemia. CD271 + progenitors are reduced and functionally impaired in insulin resistant donors.

Single-cell transcriptomics identifies adipose tissue CD271+ progenitors for enhanced angiogenesis in limb ischemia.

Therapeutic angiogenesis using mesenchymal stem/stromal cell grafts have shown modest and controversial effects in preventing amputation for patients with critical limb ischemia. Through single-cell transcriptomic analysis of human tissues, we identify CD271+ progenitors specifically from subcutaneous adipose tissue (AT) as having the most prominent pro-angiogenic gene profile distinct from other stem cell populations. AT-CD271+ progenitors demonstrate robust in vivo angiogenic capacity over conventional adipose stromal cell grafts, characterized by long-term engraftment, augmented tissue regeneration, and significant recovery of blood flow in a xenograft model of limb ischemia. Mechanistically, the angiogenic capacity of CD271+ progenitors is dependent on functional CD271 and mTOR signaling. Notably, the number and angiogenic capacity of CD271+ progenitors are strikingly reduced in insulin-resistant donors. Our study highlights the identification of AT-CD271+ progenitors with in vivo superior efficacy for limb ischemia. Furthermore, we showcase comprehensive single-cell transcriptomics strategies for identification of suitable grafts for cell therapy.

Circulating nerve growth factor receptor positive cells are associated with severity and prognosis of pulmonary arterial hypertension.

Pulmonary arterial hypertension (PAH) remains a disease with a poor prognosis, so early detection and treatment are very important. Sensitive and non-invasive markers for PAH are urgently required. This study was performed to identify sensitive markers of the clinical severity and prognosis of PAH. Patients diagnosed with PAH (n = 30) and control participants (n = 15) were enrolled in this observational study. Major EPC and MSC markers (including CD34, CD133, VEGFR2, CD90, PDGFRα, and NGFR) in peripheral blood mononuclear cells (PBMNCs) were assessed by flow cytometry. Associations of these markers with hemodynamic parameters (e.g. mean pulmonary arterial pressure, pulmonary vascular resistance, and cardiac index) were assessed. Patients with PAH were followed up for 12 months to assess the incidence of major adverse events, defined as death or lung transplantation. Levels of circulating EPC and MSC markers in PBMNCs were higher in patients with PAH than in control participants. Among the studied markers, nerve growth factor receptor (NGFR) was significantly positively correlated with hemodynamic parameters. During the 12-month follow-up period, major-event-free survival was significantly higher in patients with PAH who had relatively low frequencies of NGFR positive cells than patients who had higher frequencies. These results suggested that the presence of circulating NGFR positive cells among PBMNCs may be a novel biomarker for the severity and prognosis of PAH.

Myocyte-specific enhancer factor 2c triggers transdifferentiation of adipose tissue-derived stromal cells into spontaneously beating cardiomyocyte-like cells.

Cardiomyocyte regeneration is limited in adults. The adipose tissue-derived stromal vascular fraction (Ad-SVF) contains pluripotent stem cells that rarely transdifferentiate into spontaneously beating cardiomyocyte-like cells (beating CMs). However, the characteristics of beating CMs and the factors that regulate the differentiation of Ad-SVF toward the cardiac lineage are unknown. We developed a simple culture protocol under which the adult murine inguinal Ad-SVF reproducibly transdifferentiates into beating CMs without induction. The beating CMs showed the striated ventricular phenotype of cardiomyocytes and synchronised oscillation of the intracellular calcium concentration among cells on day 28 of Ad-SVF primary culture. We also identified beating CM-fated progenitors (CFPs) and performed single-cell transcriptome analysis of these CFPs. Among 491 transcription factors that were differentially expressed (≥ 1.75-fold) in CFPs and the beating CMs, myocyte-specific enhancer 2c (Mef2c) was key. Transduction of Ad-SVF cells with Mef2c using a lentiviral vector yielded CFPs and beating CMs with ~ tenfold higher cardiac troponin T expression, which was abolished by silencing of Mef2c. Thus, we identified the master gene required for transdifferentiation of Ad-SVF into beating CMs. These findings will facilitate the development of novel cardiac regeneration therapies based on gene-modified, cardiac lineage-directed Ad-SVF cells.

A case of pulmonary arterial hypertension with chronic hepatitis that resulted in hepatosplenomegaly after administration of prostaglandin I2.

The prognosis of pulmonary arterial hypertension (PAH) has significantly improved over the past two decades due to advances in medications, including pulmonary vasodilators. However, the side effects of these drugs remain problematic in some patients. A 51-year-old woman with chronic hepatitis C was diagnosed with PAH 7 years before presenting to our hospital. She was unable to continue her treatment with pulmonary vasodilators due to various side effects. She had a World Health Organization functional class of IV and was started on continuous infusion of prostaglandin I2 (PGI2). This therapy improved her symptoms, including dyspnea and fatigue. However, she began to complain of abdominal distension after 4 months of PGI2 therapy. Computed tomography showed significant hepatosplenomegaly. Her abdominal distension improved slightly after decreasing PGI2 treatment, but her dyspnea on exertion was exacerbated. She died 12 years after diagnosis of PAH due to uncontrollable heart failure. Here, we describe a rare case of PAH with hepatosplenomegaly after administration of PGI2. .