Background Circadian rhythm disorders, often seen in modern lifestyles, are a major social health concern. The aim of this study was to examine whether circadian rhythm disorders would influence angiogenesis and blood perfusion recovery in a mouse model of hind limb ischemia. Methods and Results A jet‐lag model was established in C57BL/6J mice using a light‐controlled isolation box. Control mice were kept at a light/dark 12:12 (12‐hour light and 12‐hour dark) condition. Concentrations of plasma vascular endothelial growth factor and circulating endothelial progenitor cells in control mice formed a circadian rhythm, which was diminished in the jet‐lag model ( P <0.05). The jet‐lag condition deteriorated tissue capillary formation ( P <0.001) and tissue blood perfusion recovery ( P <0.01) in hind limb ischemia, which was associated with downregulation of vascular endothelial growth factor expression in local ischemic tissue and in the plasma. Although the expression of clock genes (ie, Clock , Bmal1 , and Cry ) in local tissues was upregulated after ischemic injury, the expression levels of cryptochrome (Cry) 1 and Cry2 were inhibited by the jet‐lag condition. Next, Cry1 and Cry2 double‐knockout mice were examined for blood perfusion recoveries and a reparative angiogenesis. Cry1 and Cry2 double‐knockout mice revealed suppressed capillary density ( P <0.001) and suppressed tissue blood perfusion recovery ( P <0.05) in the hind limb ischemia model. Moreover, knockdown of CRY1/2 in human umbilical vein endothelial cells was accompanied by increased expression of WEE1 and decreased expression of HOXC5 . This was associated with decreased proliferative capacity, migration ability, and tube formation ability of human umbilical vein endothelial cells, respectively, leading to impairment of angiogenesis. Conclusions Our data suggest that circadian rhythm disorder deteriorates reparative ischemia‐induced angiogenesis and that maintenance of circadian rhythm plays an important role in angiogenesis.
MiRNA expression was determined in both proliferating and differentiated cardiac stem cells (CSCs) through a comprehensive miRNA microarray analysis. We selected miR218 for functional follow-up studies to examine its significance in CSCs. First, we observed that the expression of miR218 was altered in CSCs during differentiation into cardiomyocytes, and transfection of an miR218 mimic or miR218 inhibitor affected the myocardial differentiation of CSCs. Furthermore, we observed that a negative regulator of Wnt signaling, sFRP2, was a direct target of miR218, and the protein levels of sFRP2 were increased in cells transfected with the synthetic miR218 inhibitor. In contrast, transfection with the miR218 mimic decreased the expression of sFRP2 and potentiated Wnt signaling. The subsequent down-regulation of sFRP2 by shRNA potentiated Wnt signaling, contributing to a gene expression program that is important for CSC proliferation and cardiac differentiation. Specifically, canonical Wnt signaling induced miR218 transcription. Thus, miR218 and Wnt signaling were coupled through a feed-forward positive feedback loop, forming a biological regulatory circuit. Together, these results provide the first evidence that miR218 plays an important role in CSC proliferation and differentiation through the canonical Wnt signaling pathway.
Objective: Lymphatic vessels are distributed throughout the body and tightly collaborate with blood vessels to maintain tissue homeostasis. However, the functional roles of lymphangiogenesis in the process of reparative angiogenesis in ischemic tissues are largely unknown. Accordingly, we investigated potential roles of lymphangiogenesis using a mouse model of ischemia-induced angiogenesis. Approach and Results: Male C57BL/6J mice were subjected to unilateral hindlimb ischemia, in which not only angiogenesis but also lymphangiogenesis was induced. Next, the excessive and prolonged tissue edema model significantly deteriorated reparative angiogenesis and blood perfusion recovery in ischemic limbs. Finally, implantation of adipose-derived regenerative cells augmented ischemia-induced lymphangiogenesis, which was accompanied by reduced tissue edema and inflammation, resulting in improving reparative angiogenesis and blood perfusion recovery. In addition, inhibition of lymphangiogenesis by MAZ51, a specific VEGFR3 (vascular endothelial cell growth factor receptor 3) inhibitor, resulted in enhanced inflammatory cell infiltration, gene expression of TNF (tumor necrosis factor)-α, IL (interleukin)-1β, IL-6, TGF (transforming growth factor)-β, angiostatin, vasohibin, and endostatin, and tissue edema, resulting in reduced angiogenesis. Conclusions: The lymphatic system may have a clearance role of tissue edema and inflammation, which contribute to functional reparative angiogenesis in response to tissue ischemia. Modulation of lymphangiogenesis would become a novel therapeutic strategy for severe ischemic disease in addition to ordinary vascular intervention and therapeutic angiogenesis.
Plaque rupture followed by intracoronary thrombus formation is recognized as the most common pathophysiological mechanism in acute coronary syndromes (ACS). The second most common underlying substrate for ACS is plaque erosion whose hallmark is thrombus formation without cap disruption. Invasive and non-invasive methods have emerged as a promising tool for evaluation of plaque features that either predict or detect plaque erosion. Optical coherence tomography (OCT), high-definition intravascular ultrasound (IVUS), nearinfrared spectroscopy (NIRS), and near-infrared autofluorescence (NIRF) have been used to study plaque erosion. The detection of plaque erosion in the clinical setting, mainly facilitated by OCT, has shed light upon the complex pathophysiology underlying ACS not related to plaque rupture. Coronary computed tomography angiography (CCTA), which is to date the most commonly used non-invasive technique for coronary plaque evaluation, may also have a role in the evaluation of patients predisposed to erosion. Also, computational models enabling quantification of endothelial shear stress may pave the way to new research in coronary plaque pathophysiology. This review focuses on the recent imaging techniques for the evaluation of plaque erosion including invasive and non-invasive assessment.
BackgroundMicroRNAs (miRNAs) have emerged as crucial factors that regulate proliferation and apoptosis of cardiac c-kit+ cells. Although much is known about their role in maintaining cardiac c-kit+ cell pluripotency, the mechanisms by which they affect cell fate decisions that are an essential part of the repair of heart failure remain poorly understood.MethodsCardiac c-kit+ cells were obtained from Balb/c mice and cultured in vitro. Lentiviral vectors of miR199a-3p, its corresponding anti-miRNA, or short hairpin RNA against Cables1 were transfected into cells. The proliferation of cardiac c-kit+ cells was evaluated using EdU and flow cytometry. Furthermore, we examined cell apoptosis by flow cytometry under treatment with 200nM angiotensin II for 48 h. The levels of miR199a-3p and Cables1 mRNA were measured by quantitative real-time polymerase chain reaction (qRT-PCR). Western blot was performed to examine the expression of Cables1 and P53 proteins.ResultsWe demonstrated a significantly decreased expression of miR199a-3p in heart failure samples compared with healthy donors. Meanwhile, we identified miR199a-3p as a proliferation- and apoptosis-associated regulator impacted through Cdk5 and Abl enzyme substrate 1 (CABLES1) targeting, and also attributed their repression to P53 protein expression. We further demonstrated that P53 induced miR199a-3p expression and, in turn, miR199-3p decreased P53 activity.ConclusionCollectively, our findings uncover one new mechanism by which P53 induced miR199a-3p expression and, in turn, miR199-3p decreased P53 activity. Therefore, miR199a-3p and P53 are coupled through CABLES1 and comprise a novel negative feedback loop that likely contributes to cardiac c-kit+ cell proliferation and apoptosis.
Therapeutic angiogenesis with autologous stem/progenitor cells is a promising novel strategy for treatment of severe ischemic diseases. Human clinical trials utilizing autologous adipose-derived regenerative cells (ADRCs) have not reported treatment-related critical adverse effects thus far. However, there is still a large knowledge gap whether treatment of ischemic diseases with angiogenic therapy using ADRCs would promote unfavorable angiogenesis associated with tumors in vivo. Herein, we addressed this clinical question using a mouse hind limb ischemia (HLI) and simultaneous remote tumor implantation model. C57BL/6J background wild-type mice were injected with murine B16F10 melanoma cells on their back, one day before ischemic surgery. These mice were subjected to surgical unilateral hindlimb ischemia, followed by ADRCs implantation or PBS injection into the hindlimb ischemic muscles on the next day. Intramuscular implantation of ADRCs enhanced tissue capillary density and blood flow examined by a laser Doppler blood perfusion analysis in hind limb. However, this therapeutic regimen for ischemic limb using ADRCs did not affect remote melanoma growth nor the density of its feeder artery, angiogenesis and lymphatic vessels compared to the PBS group. In addition, no distant metastases were detected in any of the mice regardless the group. In conclusion, local implantation of ADRCs promotes angiogenesis in response to tissue ischemia in the hind limb without promoting remote tumor growth and related angio/lymphangiogenesis. Therapeutic angiogenesis to the ischemic hind limb using ADRCs seems to be safe regarding remote tumor growth.
Cables1 (Cdk5 and Abl enzyme substrate 1) is a vital cell cycle regulator and a candidate tumor suppressor that negatively regulates cell growth by inhibiting cyclin-dependent kinases. Here, we report on the critical role of the Cables1/p21 pathway, which inhibits cell proliferation and induces cell senescence in human umbilical vein endothelial cells. Moreover, we confirmed that silencing of Cables1 promoted cell proliferation as well as increased resistance to angiotensin II-induced senescence, at least in part, by altering Cables1 activation. We further demonstrated that knockdown of p21 reverses Cables1-mediated cell growth inhibition and cell senescence. Taken together, these results suggest that the Cables1/p21 pathway has a strong effect on the induction of cell senescence and inhibition of cell growth, and acts as a novel regulatory mechanism in which p21 is probably one of several downstream effector molecules to mediate Cables1.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.