Effects of tafamidis on the left ventricular and left atrial strain in patients with wild-type transthyretin cardiac amyloidosis.

AIMS: Although tafamidis is used in patients with wild-type transthyretin cardiac amyloidosis (ATTRwt-CA), its specific effect on cardiac function is unclear. Thus, this study aimed to investigate the effect of tafamidis on left atrial (LA) and left ventricular function using speckle-tracking echocardiography for 1 year of treatment in patients with ATTRwt-CA. METHODS AND RESULTS: We included 23 patients (mean age, 76 years) with ATTRwt-CA confirmed via biopsy. We analysed the left ventricular and LA strain using 2D speckle-tracking echocardiography and compared these parameters before and 1 year after starting treatment with tafamidis between 16 patients with sinus rhythm (SR) and 7 patients with atrial fibrillation (AF). In ATTRwt-CA patients with SR, LA reservoir strain significantly improved by 1-year tafamidis treatment (10.5 ± 5.0% to 11.9 ± 5.3%, P = 0.0307) although global longitudinal strain (GLS) did not (-10.6 ± 3.1% to -11.3 ± 3.0%, P = 0.0608). In contrast, LA reservoir strain was not significantly changed (5.4 ± 2.9% to 4.9 ± 1.7%, P = 0.4571), and GLS deteriorated (-8.4 ± 2.3% to -6.8 ± 1.4%, P = 0.0267) in ATTRwt-CA patients with AF. CONCLUSION: LA function improved with tafamidis treatment in ATTRwt-CA patients with SR but not left ventricular function. However, these cardiac functions did not improve with tafamidis treatment in ATTRwt-CA patients with AF.

Real-world Safety and Effectiveness of Edoxaban in Patients with Venous Thromboembolism with or without Preceding Parenteral Anticoagulants: A Single-center Retrospective Study.

Objective Edoxaban is an anticoagulant used for venous thromboembolism (VTE) treatment and requires pretreatment with parenteral anticoagulants. However, pretreatment is not always performed in the clinical setting. In this study, we investigated the safety and effectiveness of edoxaban treatment in patients with VTE with or without pretreatment. Methods We retrospectively enrolled 364 patients who received edoxaban for VTE treatment between September 2014 and March 2020 and investigated patient demographics, VTE recurrence, and major bleeding as clinical outcomes in patients with or without pretreatment. Furthermore, the factors contributing to pretreatment decisions were assessed. Results Patients without pretreatment (n=208) had more active cancer cases and fewer pulmonary embolism complications than those with pretreatment (n=156). Lower levels of hemoglobin and higher levels of white blood cell counts, C-reactive protein, and D-dimer at the diagnosis were found in patients who received pretreatment than in those without pretreatment. No symptomatic VTE recurrence was observed. After propensity score matching, the cumulative incidence of major bleeding was not significantly higher in patients with pretreatment than in those without it (log-rank test, p=0.136). The incidence of deteriorated VTE on imaging did not significantly differ between patients with and without pretreatment, even after propensity matching (log-rank test, p=0.414). Conclusion In a real-world clinical setting, where physicians determined the use of parenteral anticoagulant lead-in according to their experience, patient demographics, and VTE characteristics, no significant differences were found regarding safety and effectiveness in edoxaban-treated VTE patients with or without pretreatment with parenteral anticoagulants.

Regeneration of the ureter using a scaffold-free live-cell structure created with the bio-three-dimensional printing technique.

Ureteral strictures, which can be caused by ureteral injury, radiation therapy, ureterolithiasis, urinary tract infections, and ureteral endometriosis, typically require ureteral reconstruction. Although tissue engineering, autologous alternative tissue transplantation, and surgical techniques applying various flaps have been carried out for ureteral regeneration, all with some success, each method has its advantages and disadvantages. As an alternative, we created the first artificial ureter structures using only live cells and grafted them into healthy rat ureters. Spheroids were created using normal human dermal fibroblasts and human umbilical vein endothelial cells and subsequently laminated using a bio-three-dimensional printer. After molding the laminated spheroids into tubular structures, the artificial ureters were transplanted into live rats. After 2-12 weeks, the animals were sacrificed and their gross and pathological features were examined. In the artificial ureteral lumen of rats with Grade 0-1 hydronephrosis, regeneration of the ureteral epithelium was observed, the thickness of which increased over the course of the experiment. Regeneration of the muscular layer was also observed, extending from the normal ureteral side toward the artificial ureter structure over time. However, complete regeneration was not observed at the end of 12 weeks. Although ureteral peristalsis was noted in all cases, it was weaker than expected. Therefore, we achieved short-segment ureteral regeneration using a cell-only structure. This finding suggests that by applying alternative strategies to this method, such as changing the cell type and composition, regeneration over the entire length of the ureter may be possible in the future. STATEMENT OF SIGNIFICANCE: Until now, ureteral regeneration techniques have been dominated by the use of high-molecular-weight compounds and autologous tissues, and there have been no reports of regeneration using structures made entirely of cells. This is the first report of ureteral regeneration using a tubular structure made from stacked spheroids. Although this study only attained short-segment ureteral regeneration, regeneration of the ureter over a much longer proportion of its length can be achieved in the future by applying other strategies, such as changing the cell type. This study provides a foundation to achieve the future goal of complete regeneration.

Pathological features of biopsied myocardium in patients clinically diagnosed with peripartum cardiomyopathy.

The etiology of peripartum cardiomyopathy (PPCM) is unknown. Therefore, we evaluated the etiology of patients clinically diagnosed with PPCM using endomyocardial biopsy. We studied five patients diagnosed with PPCM following endomyocardial biopsy (age, 28-42 years; mean age, 35 years). Biopsied samples were evaluated using microscopy, including immunostaining and electron microscopy. The pathological findings were as follows: myocardial hypertrophy, myocardial fibrosis, and cell infiltration. Two patients were diagnosed with lymphocytic myocarditis, one with eosinophilic myocarditis, one with hypertensive heart disease, and one with a combination of hypertension and myocarditis. Endomyocardial biopsy suggested that the causes of PPCM were varied and related to myocarditis and myocardial overload due to hypertension.

Comparison of Effectiveness and Safety Among 3 Direct Oral Anticoagulants in Patients With Venous Thromboembolism　- A Single-Center Retrospective Study.

Background: Direct oral anticoagulants (DOACs), including edoxaban, rivaroxaban, and apixaban, are administered for the treatment of venous thromboembolism (VTE) in Japan. However, only a few reports have compared the effectiveness and safety of these DOACs. Methods and Results: We retrospectively enrolled 702 patients who received DOACs for VTE treatment between September 2014 and March 2020. We investigated patient demographics, VTE recurrence, major bleeding, and mortality until March 2021, and compared them among the 3 DOACs. Most patients (~70%; n=496) were prescribed edoxaban, followed by apixaban (n=107) and rivaroxaban (n=99). Age, body mass index, renal function, and the proportion of cancer patients did not differ significantly among the DOACs. Edoxaban was administered relatively more in women with low body weight and anemia. The rate of pulmonary embolism was significantly lower among patients receiving edoxaban than apixaban or rivaroxaban (24.4% vs. 41.1% and 53.5%, respectively). VTE reoccurred in 2 patients administered apixaban and 1 patient administered edoxaban. The cumulative incidence of major bleeding at 1 year was 11.7%, 18.5%, and 9.0% in the edoxaban, apixaban, and rivaroxaban groups, respectively. There were no significant differences in the cumulative incidence of major bleeding and all-cause death, estimated by Kaplan-Meier analysis, among the DOACs (log-rank P=0.316 and 0.722, respectively). Conclusions: The safety of the 3 DOACs did not differ significantly in clinical settings, despite differences in patient demographics.

Comparison of Dasatinib- and Imatinib-Related Cardiotoxic Adverse Events in Japanese Patients With Chronic Myeloid Leukemia and Gastrointestinal Stromal Tumor.

Background: Despite the beneficial effects of BCR-ABL1 tyrosine kinase inhibitors (TKIs) in the treatment of chronic myeloid leukemia (CML), they may also cause adverse events (AEs), especially cardiovascular toxicity. The incidence of TKI-induced AEs may vary among ethnic groups, and there is little specific information for Japanese patients. Methods and Results: Sixty-nine consecutive patients who were started on treatment with dasatinib (n=25) or imatinib (n=44) for CML or gastrointestinal stromal tumor (GIST) between December 2008 and December 2019 were retrospectively recruited to the study. We determined the prevalence of AEs through October 2020 and compared the incidence of AEs between the 2 drugs. Baseline characteristics were comparable between the 2 groups. However, compared with the imatinib-treated group, the dasatinib-treated group had a higher incidence of congestive heart failure (CHF; 20.0% vs. 2.3%; P=0.04), pleural effusion (48% vs. 20.5%; P=0.03), pericardial effusion (24% vs. 4.6%; P=0.02), QT prolongation (4 vs. 0 patients; P=0.02), and pulmonary hypertension (3 vs. 0 patients; P=0.04). In the dasatinib-treated group, CHF tended to be associated with tricuspid valve regurgitation pressure gradient, and pleural effusion was observed in all patients. All-cause mortality and other cardiovascular events did not differ significantly between the 2 groups. Conclusions: Cardiotoxic AEs occurred more frequently in Japanese patients with CML and GIST treated with dasatinib than imatinib.

Febuxostat, a Xanthine Oxidase Inhibitor, Decreased Macrophage Matrix Metalloproteinase Expression in Hypoxia.

Macrophages in the atheroma region produce matrix metalloproteinases (MMPs) and decrease plaque stability. Tissue oxygen tension decreases in the arterial wall of the atherosclerotic region. Hypoxia inducible factor (HIF)-1α plays a critical role in the transcriptional activation of hypoxia inducible genes. However, the precise roles of HIF-1α independent pathways in hypoxic responses are largely unknown. Xanthine oxidase (XO) is an enzyme that utilizes molecular oxygen and produces reactive oxygen species (ROS). Here, we show that ROS derived from XO increases MMP-3, -10, and -13 expression in murine macrophages. We found that the transcript levels of macrophage MMP-3, -10, and -13 were increased in hypoxic conditions. Hypoxia induced MMP expression in HIF-1α deficient macrophages. N-acetylcysteine (NAC) or febuxostat, an XO inhibitor, suppressed MMP expression in murine macrophages. Febuxostat decreased the incidence of plaque rupture in apolipoprotein-E-deficient mice. Our results indicate that febuxostat stabilized atherosclerotic plaque via suppressing the activities of macrophage MMP-9 and -13. Febuxostat administration is a potential therapeutic option in the management of atherosclerotic patients.

Effectiveness and safety of oral direct factor Xa inhibitors for the treatment of venous thromboembolism in patients with cancer and/or older age.

Venous thromboembolism (VTE) is a multifactorial disease. Cancer and older age are risk factors for both recurrent VTE and bleeding under anticoagulant therapy. Oral direct factor Xa inhibitors (Xa inhibitors) have been widely used to treat VTE. However, their effectiveness and safety in cancer and elderly patients have not been fully elucidated. A total of 187 consecutive patients who started Xa inhibitors for VTE therapy between September 2014 and September 2016 were recruited. Patients' demographics, changes in VTE amount, VTE recurrence, clinically relevant bleeding, and death until February 2017 were compared between 92 cancer and 95 non-cancer patients, and 57 elderly (≥ 75 years) and 130 non-elderly patients. Compared with non-cancer patients, cancer patients had a significantly higher incidence of deep vein thrombosis (DVT) in the proximal legs, superior vena cava, and upper extremities (p = 0.034), although the patients' demographics and incidence of pulmonary thromboembolism (PE) were similar between the two groups. There were no significant differences in VTE recurrence (p = 0.328) and clinically relevant bleeding (p = 0.078) between the two groups. Death occurred in 29 cancer patients, 23 of whom died of cancer, while there were no deaths among the non-cancer patients. Elderly patients had a lower body weight and creatinine clearance than non-elderly patients. No significant differences between the two groups were found in relation to PE (p = 0.544), DVT site (p = 0.054), recurrent VTE (p = 0.194), clinically relevant bleeding (p = 0.130) and death (p = 0.241). In comparisons among the four groups (elderly and non-elderly patients with and without cancer), recurrent VTE and clinically relevant bleeding were comparable (p = 0.493 and 0.227, respectively), while death was more frequent in cancer patients regardless of age (p < 0.001). The efficacy and safety of Xa inhibitors as VTE treatment were comparable between cancer and non-cancer patients, and in elderly and non-elderly patients. This suggests that Xa inhibitors may be promising drugs for VTE treatment, irrespective of age and comorbid cancer.

Comparison of the effects of edoxaban, an oral direct factor Xa inhibitor, on venous thromboembolism between patients with and without cancer.

BACKGROUND: Venous thromboembolism (VTE) is a frequent and serious complication of cancer. The current guidelines in the USA and Europe recommend low-molecular weight heparin (LMWH) for the treatment of cancer-associated VTE. In Japan, LMWH is not given for the treatment of VTE; instead edoxaban, an oral direct factor Xa inhibitor, was approved for the treatment of VTE in September 2014. However, the efficacy and safety of the factor Xa inhibitor in cancer patients have not been fully elucidated. METHODS: Patients' charts were reviewed retrospectively, and 125 VTE patients (61 cancer patients) in whom edoxaban therapy was started between September 2014 and September 2016 were included in this study. Patients' demographics, changes in VTE amount, VTE recurrence, clinically relevant bleeding, and outcomes until February 2017 were examined. RESULTS: Patients' characteristics, including age, sex, weight, creatinine clearance, and duration of administration of edoxaban were comparable between cancer and non-cancer patients. No parenteral anticoagulant pretreatment before edoxaban was given in 37.5% and 55.7% of non-cancer and cancer patients, respectively. The incidence of pulmonary embolism was also similar in the two groups. The amount of thrombosis decreased ("improved") or disappeared ("normalized") in 89.6% and 94.1%, respectively, of non-cancer and cancer patients who underwent at least two imaging tests. The frequencies of recurrence of VTE and clinically relevant bleeding were not significantly different between the two groups (p=0.414 and 0.516, respectively). However, 21 cancer patients died, 17 of whom died of cancer, while none of the non-cancer patients died. CONCLUSION: The present study showed that the efficacy and safety of edoxaban for the treatment of VTE is comparable between cancer and non-cancer patients. Edoxaban may be a clinically useful therapy for VTE in Japanese cancer patients.

Jagged-1 Signaling in the Bone Marrow Microenvironment Promotes Endothelial Progenitor Cell Expansion and Commitment of CD133+ Human Cord Blood Cells for Postnatal Vasculogenesis.

Notch signaling is involved in cell fate decisions during murine vascular development and hematopoiesis in the microenvironment of bone marrow. To investigate the close relationship between hematopoietic stem cells and human endothelial progenitor cells (EPCs) in the bone marrow niche, we examined the effects of Notch signals [Jagged-1 and Delta-like ligand (Dll)-1] on the proliferation and differentiation of human CD133+ cell-derived EPCs. We established stromal systems using HESS-5 murine bone marrow cells transfected with human Jagged-1 (hJagged-1) or human Dll-1 (hDll-1). CD133+ cord blood cells were co-cultured with the stromal cells for 7 days, and then their proliferation, differentiation, and EPC colony formation was evaluated. We found that hJagged-1 induced the proliferation and differentiation of CD133+ cord blood EPCs. In contrast, hDll-1 had little effect. CD133+ cells stimulated by hJagged-1 differentiated into CD31+/KDR+ cells, expressed vascular endothelial growth factor-A, and showed enhanced EPC colony formation compared with CD133+ cells stimulated by hDll-1. To evaluate the angiogenic properties of hJagged-1- and hDll-1-stimulated EPCs in vivo, we transplanted these cells into the ischemic hindlimbs of nude mice. Transplantation of EPCs stimulated by hJagged-1, but not hDll-1, increased regional blood flow and capillary density in ischemic hindlimb muscles. This is the first study to show that human Notch signaling influences EPC proliferation and differentiation in the bone marrow microenvironment. Human Jagged-1 induced the proliferation and differentiation of CD133+ cord blood progenitors compared with hDll-1. Thus, hJagged-1 signaling in the bone marrow niche may be used to expand EPCs for therapeutic angiogenesis.

Adipose-derived regenerative cell therapy inhibits the progression of monocrotaline-induced pulmonary hypertension in rats.

AIMS: Functional and structural changes in pulmonary vasculature characterize pulmonary arterial hypertension (PAH) and the prognosis of advanced PAH remains poor despite progress in pharmacotherapy. Adipose-derived regenerative cells (ADRCs) promote cell regeneration at pathological sites and comprise a novel therapy for ailments of various organs. We investigated the effects of ADRC therapy in rat models of monocrotaline (MCT)-induced pulmonary hypertension (PH) and the underlying mechanisms. MAIN METHODS: Rats were assigned to Control and MCT groups without and with (M/A) intravenous transfusion of seven million ADRCs on day 7. We echocardiographically evaluated pulmonary hypertension as pulmonary artery flow acceleration time (PAAT) and deceleration (PADc). Right ventricular (RV) systolic pressure was measured by catheterization on day 28 and then pathological changes in pulmonary vessels were assessed. We analyzed PAH-associated gene expression on day 14 using real-time RT-PCR. KEY FINDINGS: Echocardiography and RV catheterization showed that ADRC therapy inhibited PH development (assessed as PAAT, PADc, and RV systolic pressure) at day 28 (MCT vs. M/A, P<0.05). Pulmonary vascular remodeling was also inhibited (vessel wall thickness: MCT vs. M/A, P<0.01). Messenger RNA levels of endothelin (ET) A and B receptors, ET-1 and transforming growth factor (TGF)-ß increased in the lungs by MCT were suppressed by ADRCs (MCT vs. M/A, P<0.05). SIGNIFICANCE: The development of PH was inhibited by ADRCs through suppressing changes in the expression of genes associated with ET and TGF-ß systems. We believe that ADRC therapy could serve as a novel strategy for treating PH.

Cyclophosphamide-induced cardiotoxicity with a prolonged clinical course diagnosed on an endomyocardial biopsy.

A 31-year-old woman with primary mediastinal large B-cell lymphoma refractory to conventional chemotherapy was treated with high-dose chemotherapy containing cyclophosphamide (CY). Subsequently, she was treated with auto peripheral blood stem cell transplantation. Although a complete remission was obtained, heart failure developed two months later. Echocardiography showed an impaired systolic function with pericardial effusion. A biopsy of the endomyocardial region from the left ventricle demonstrated spotty myocardial hemorrhage and myocardial fibrosis with disruption and aggregation of mitochondrial cristae. Based on these findings, CY-induced cardiotoxicity was diagnosed. The patient was treated with conventional therapy for heart failure, which required approximately one year to improve her condition.

Pivotal role of lnk adaptor protein in endothelial progenitor cell biology for vascular regeneration.

Despite the fact that endothelial progenitor cells (EPCs) are important for postnatal neovascularization, their origins, differentiation, and modulators are not clear. Here, we demonstrate that Lnk, a negative regulator of hematopoietic stem cell proliferation, controls endothelial commitment of c-kit(+)/Sca-1(+)/Lineage(-) (KSL) subpopulations of bone marrow cells. The results of EPC colony-forming assays reveal that small (primitive) EPC colony formation by CD34(-) KSLs and large (definitive) EPC colony formation by CD34((dim)) KSLs are more robust in lnk(-/-) mice. In hindlimb ischemia, perfusion recovery is augmented in lnk(-/-) mice through enhanced proliferation and mobilization of EPCs via c-Kit/stem cell factor. We found that Lnk-deficient EPCs are more potent actors than resident cells in hindlimb perfusion recovery and ischemic neovascularization, mainly via the activity of bone marrow-EPCs. Similarly, lnk(-/-) mice show augmented retinal neovascularization and astrocyte network maturation without an increase in indicators of pathogenic angiogenesis in an in vivo model of retinopathy. Taken together, our results provide strong evidence that Lnk regulates bone marrow-EPC kinetics in vascular regeneration. Selective targeting of Lnk may be a safe and effective strategy to augment therapeutic neovascularization by EPC transplantation.

Lesion-targeted thrombopoietin potentiates vasculogenesis by enhancing motility and enlivenment of transplanted endothelial progenitor cells via activation of Akt/mTOR/p70S6kinase signaling pathway.

Thrombopoietin (TPO), a physiological regulator of megakaryocyte and platelet development, is a multifunctional positive regulator in early hematopoiesis by hematopoietic stem cells. In this study, we investigated the effect of TPO on endothelial progenitor cells (EPCs) for therapeutic vasculogenesis in vitro and in vivo, and the intracellular signaling mechanism exerting the activity of EPCs. 7-day culture-expanded EPCs derived from human peripheral blood mononuclear cells were applied to each assay. Flow cytometry demonstrated the expression of c-Mpl, the receptor of TPO, in cultured EPCs. In vitro experiments revealed enhanced migration and survival of cultured EPCs by TPO. In vivo, TPO was intramuscularly administered into the foci of ischemic hindlimbs in athymic nude mice, immediately followed by intravenous injection of cultured EPCs, to assess the booster effect of TPO on vascular regeneration. At day 4 post-transplantation, transplanted EPCs were 1.7-fold higher in TPO-treated animals compared to control. At day 28, blood perfusion was recovered in the TPO-treated group, accompanied by an increase in microvascular density. The signaling transduction pathway underlying TPO-mediated activities of cultured EPCs was assessed by Western blotting. TPO induced sequential phosphorylations of Akt to p70S6kinase through mTOR. Inhibition of the PI3-kinase/Akt/mTOR/p70S6kinase signaling pathway negated the biological functions of cultured EPCs, either migration (by LY294002 for PI3-kinase and Rapamycin for mTOR) or survival and tubulogenesis (by Rapamycin). These findings provide evidence that TPO possesses booster potential for therapeutic vasculogenesis, by activating the PI3-kinase/Akt/mTOR/p70S6kinase pathway crucial to the biological activities of EPCs.

Specific Jagged-1 signal from bone marrow microenvironment is required for endothelial progenitor cell development for neovascularization.

BACKGROUND: Despite accumulating evidence that proves the pivotal role of endothelial progenitor cells (EPCs) in ischemic neovascularization, the key signaling cascade that regulates functional EPC kinetics remains unclear. METHODS AND RESULTS: In this report, we show that inactivation of specific Jagged-1 (Jag-1)-mediated Notch signals leads to inhibition of postnatal vasculogenesis in hindlimb ischemia via impairment of proliferation, survival, differentiation, and mobilization of bone marrow-derived EPCs. Bone marrow-derived EPCs obtained from Jag-1-/- mice, but not Delta-like (Dll)-1-/- mice, demonstrated less therapeutic potential for ischemic neovascularization than EPCs from the wild type. In contrast, a gain-of-function study using 3T3 stromal cells overexpressing Notch ligand revealed that Jag-1-mediated Notch signals promoted EPC commitment, which resulted in enhanced neovascularization. The impaired neovascularization in Jag-1-/- mice was profoundly rescued by transplantation of Jag-1-stimulated EPCs. CONCLUSIONS: These data indicate that specific Jag-1-derived Notch signals from the bone marrow microenvironment are critical for EPC-mediated vasculogenesis, thus providing an important clue for modulation of strategies for therapeutic neovascularization.

Nicotine enlivenment of blood flow recovery following endothelial progenitor cell transplantation into ischemic hindlimb.

Nicotine has been demonstrated to stimulate postnatal angiogenesis, having an antiapoptotic effect on endothelial cells. Given the extent of this angiogenesis-promoting effect, we hypothesized that nicotine may also stimulate postnatal vasculogenesis on endothelial progenitor cells (EPCs). Our analyses reveal some intriguing results using an in vitro assay with 2 x 10(-6) M of nicotine (smoker's average nicotine concentration and the dose of nicotine replacement therapy). The proliferation and migration activities of human EPCs cultured from peripheral blood mononuclear cells of non-smoking healthy volunteers were not affected by nicotine. The effect of nicotine on EPC survival was significantly enhanced under serum starvation on the ratio of Hoechest 33342-stained pyknotic nuclear cells as well as Annexin-V-stained cells to total cells. Furthermore, the antiapoptotic effect of nicotine was blocked completely by nicotinic acetylcholine receptor (nAChR) antagonist hexamethonium. Next, we verified how nicotine acts in vivo. Nicotine (100 ng/ml) was administered orally for 7 days before and 4 weeks after injection of cultured EPCs (1 x 10(5) /mouse) into the tail veins of 8-week-old athymic nude mice with ischemic hindlimbs. Laser doppler imaging analysis indicated that blood perfusion in the ischemic hindlimb was significantly enhanced in EPCs plus nicotine, as compared with EPCs alone. These findings suggest nicotine improves blood flow following EPC transplantation in patients with ischemic diseases.

Estrogen-mediated endothelial progenitor cell biology and kinetics for physiological postnatal vasculogenesis.

Estrogen has been demonstrated to promote therapeutic reendothelialization after vascular injury by bone marrow (BM)-derived endothelial progenitor cell (EPC) mobilization and phenotypic modulation. We investigated the primary hypothesis that estrogen regulates physiological postnatal vasculogenesis by modulating bioactivity of BM-derived EPCs through the estrogen receptor (ER), in cyclic hormonally regulated endometrial neovascularization. Cultured human EPCs from peripheral blood mononuclear cells (PB-MNCs) disclosed consistent gene expression of ER alpha as well as downregulated gene expressions of ER beta. Under the physiological concentrations of estrogen (17beta-estradiol, E2), proliferation and migration were stimulated, whereas apoptosis was inhibited on day 7 cultured EPCs. These estrogen-induced activities were blocked by the receptor antagonist, ICI182,780 (ICI). In BM transplanted (BMT) mice with ovariectomy (OVX) from transgenic mice overexpressing beta-galactosidase (lacZ) regulated by an endothelial specific Tie-2 promoter (Tie-2/lacZ/BM), the uterus demonstrated a significant increase in BM-derived EPCs (lacZ expressing cells) incorporated into neovasculatures detected by CD31 immunohistochemistry after E2 administration. The BM-derived EPCs that were incorporated into the uterus dominantly expressed ER alpha, rather than ER beta in BMT mice from BM of transgenic mice overexpressing EGFP regulated by Tie-2 promoter with OVX (Tie-2/EGFP/BMT/OVX) by ERs fluorescence immunohistochemistry. An in vitro assay for colony forming activity as well as flow cytometry for CD133, CD34, KDR, and VE-cadherin, using human PB-MNCs at 5 stages of the female menstrual-cycle (early-proliferative, pre-ovulatory, post-ovulatory, mid-luteal, late-luteal), revealed cycle-specific regulation of EPC kinetics. These findings demonstrate that physiological postnatal vasculogenesis involves cyclic, E2-regulated bioactivity of BM-derived EPCs, predominantly through the ER alpha.

Endothelial progenitor cells for postnatal vasculogenesis.

Bone marrow-derived endothelial progenitor cells (EPCs) are present in the systemic circulation, are augmented in response to certain cytokines and/or tissue ischemia, and are home to--as well as incorporate into--sites of neovascularization. On the basis of these aspects, EPCs have attractive potential therapeutic applications for cardiovascular ischemic diseases as a novel cell-based strategy, mainly via a vasculogenesis mechanism. This review provides an update of the biology of EPCs, as well as highlighting the potential use of these cells for therapeutic regeneration.

Establishment of a functionally active collagen-binding vascular endothelial growth factor fusion protein in situ.

OBJECTIVE: Tissue regeneration requires both growth factor and extracellular matrix such as collagen, serving as a scaffold for cell growth. We established FNCBD-VEGF121, consisting of the fibronectin collagen-binding domain (FNCBD) and vascular endothelial growth factor (VEGF) 121, and investigated its properties. METHODS AND RESULTS: FNCBD-VEGF121 specifically bound to gelatin and type I, II, III, IV, and V collagen. This collagen-bound FNCBD-VEGF121 captured soluble VEGF receptor 2 (VEGFR-2)/Fc chimeric protein. Cell growth-promoting activity of FNCBD-VEGF121 was almost identical to that of VEGF121. The VEGF fusion protein significantly enhanced the expression of VEGFR-2 (71.6+/-0.8%) on endothelial progenitor cells (EPCs) derived from umbilical cord blood. Expectably, the collagen-bound VEGF fusion protein not only promoted the growth of endothelial cells (ECs) but also induced the expression of VEGFR-2 (63.7+/-0.8%) on non-adherent cells expanded from bone marrow CD34+ cells. Moreover, the VEGF fusion protein enhanced sprout formation of ECs in a matrigel model. In vivo experiments revealed that FNCBD-VEGF121 had local effects but not systemic effect on EPC mobilization. CONCLUSIONS: These results suggest that FNCBD-VEGF121 stably maintains an optimally high and local concentration of VEGF with collagen matrix and stimulates both ECs and EPCs in situ, supplying a vascular regeneration niche.