[Show abstract][Hide abstract] ABSTRACT: Peripheral artery disease (PAD), which is caused by atherosclerosis, results in progressive narrowing and occlusion of the peripheral arteries and inhibits blood flow to the lower extremities. Therapeutic angiogenesis is a promising strategy for treating ischemia caused by PAD. Nitric oxide (NO) has been shown to be a key mediator of angiogenesis. It has been demonstrated that β-cyclodextrincan stimulate vessel growth in rabbit corneas. In this study, we assessed the mechanism of action and therapeutic potential of a new angiogenic molecule, (2-hydroxypropyl)-β-cyclodextrin (2HP-β-CD).
2HP-β-CD significantly increased vascular endothelial growth factor A (VEGF-A) and platelet-derived growth factor BB (PDGF-BB) peptides in human umbilical vein endothelial cells (HUVECs) and also increased basic fibroblast growth factor (bFGF) peptide in human aortic smooth muscle cells (HASMCs). 2HP-β-CD stimulated both proliferation and migration of HUVECs in an endothelial nitric oxide synthase (eNOS)/NO-dependent manner, whereas NO was found to be involved in proliferation, but not migration, of HASMCs. In a unilateral hindlimb ischemia model in mice, 2HP-β-CD injections not only promoted blood flow recovery and increased microvessel densities in ischemic muscle, but also promoted coverage of the vessels with smooth muscle cells, thus stabilizing the vessels. Administration of 2HP-β-CD increased the expression of several angiogenic factors, including VEGF-A, PDGF-BB and transforming growth factor beta-1 (TGF-β1) in ischemic muscle. Injections of 2HP-β-CD also stimulated protein kinase B and extracellular regulated protein kinases (ERK), leading to an increase in phosphorylation of eNOS in ischemic muscle. Treatment with the NOS inhibitor, Nω-nitro-L-arginine methyl ester (L-NAME), showed that stimulation of blood flow induced by 2HP-β-CD was partially dependent on NO.
Therapeutic angiogenesis by 2HP-β-CD may be beneficial to patients with PAD.
PLoS ONE 05/2015; 10(5):e0125323. DOI:10.1371/journal.pone.0125323 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Self-healing phenomenon was found in the periarterial elastase-induced abdominal aortic aneurysm (AAA) in rabbit. This kind of aneurysm model does not progress and heals spontaneously in the long term, which is quite different from the performance of AAA disease in human. In order to better mimic human AAA and overcome this shortcoming of traditional AAA model in rabbit, we studied the pathogenesis of cerebral aneurysm (CA) model in small animal, which shows an excellent long-term patency and progressive enlargement. We found that hemodynamic conditions, such as turbulence flow, high blood flow, and shear stress, play an important role in the formation and progression of CA. So, we hypothesize that hemodynamic change may also play an essential role in the initiation and progression of rabbit AAA, and self-healing will be overcome if hemodynamic condition changes by coarctation of infra-renal aorta after elastase incubation.
[Show abstract][Hide abstract] ABSTRACT: This study tested the hypothesis that an experimental model of abdominal aortic aneurysm in rabbits results in progressive enlargement when induced by a combination of periaortic elastase administration and aortic coarctation.
Male New Zealand white rabbits were randomly divided into four groups: (A) stenosis (n = 12), (B) elastase (n = 12), (C) aneurysm (n = 15), and (D) control (n = 12). The stenosis group received an extrinsic coarctation below the right renal artery, the elastase group received a 10-minute administration of 60 μL elastase (1 U/μL) in a 1.5-cm aortic segment, the aneurysm group received stenosis and elastase, and a sham operation was performed in the control group. The aortic diameter was measured after 1, 2, 4, 8, and 16 weeks, and animals were subsequently euthanized for histopathologic and immunohistochemical studies.
All animals in the aneurysm group developed aneurysm by 2 weeks after treatment, with average diameters of 5.21 ± 0.74 mm by 2 weeks, 6.23 ± 1.10 mm by 4 weeks, 7.87 ± 0.50 mm by 8 weeks, and 9.40 ± 0.36 mm by 16 weeks. Aortic diameter dilated progressively, and all aneurysms developed by 4 weeks in the stenosis group (4.17 ± 0.22 mm). Only one aneurysm was seen in the elastase group by week 1 (3.60 ± 0.64 mm), and no aneurysm formed in the control group by week 8 (2.47 ± 0.38 mm). The aneurysm group exhibited less media thickness, elastin content, and endothelial recovery, but stronger expression of matrix metalloproteinase 2 and 9 and rabbit macrophage compared with the control group.
This novel rabbit abdominal aortic aneurysm model with a gradually enlarging diameter is simply and reliably induced, appropriately mimicking human aortic aneurysm disease.
Journal of vascular surgery: official publication, the Society for Vascular Surgery [and] International Society for Cardiovascular Surgery, North American Chapter 04/2014; DOI:10.1016/j.jvs.2014.02.062 · 2.98 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Clinical Relevance
Experimental abdominal aortic aneurysm (AAA) models can be useful to investigate its pathogenesis and to mimic human AAA disease. Medial injury aneurysms induced by elastase or calcium chloride are popular models. Unfortunately, the elastase-induced aneurysm dilates <70% and heals spontaneously. Periaortic calcium chloride application does not always induce reliable AAA formation. In this study, a novel AAA model was induced in rabbits by periaortic elastase incubation and aortic coarctation. Elastase incubation and turbulent flow caused by coarctation could work in concert to develop AAA progressively to overcome the self-healing phenomenon and to better mimic human AAA disease.
[Show abstract][Hide abstract] ABSTRACT: The overall prognosis for malignant glioma is extremely poor, and treatment options are limited in part because of multidrug resistant proteins. Our previous findings suggest low intensity ultrasound (LIUS) can induce apoptosis of glioma cells. Given this finding, we were interested in determining if LIUS could help treat glioma by inhibiting multidrug resistant proteins, and if so, which pathways are involved. In this study, the toxicity sensitivity and multidrug resistance proteins of glioma induced by LIUS were investigated using CCK-8, immunohistochemistry, immunofluorency, and RT-PCR in tissue samples and cultured cells. LIUS inhibited increase of C6 cells in an intensity- and time-dependent manner. The toxicity sensitivity of C6 cells increased significantly after LIUS sonication (intensity of 142.0 mW/cm(2)) or Doxorubicin (DOX) at different concentration, particularly by the combination of LIUS sonication and DOX. The expressions of P-gp and MRP1 decreased significantly post-sonication at intensity of 142.0 mW/cm(2) both in vitro and in vivo. The expressions of p110 delta (PI3K), NF-κB-p65, Akt/PKB, and p-Akt/PKB were downregulated by LIUS sonication and DOX treatment separately or in combination at the same parameters in rat glioma. These results indicate that LIUS could increase the toxicity sensitivity of glioma by down-regulating the expressions of P-gp and MRP1, which might be mediated by the PI3K/Akt/NF-κB pathway.
PLoS ONE 08/2013; 8(8):e70685. DOI:10.1371/journal.pone.0070685 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The purpose of this study was to introduce a novel, simple and effective technique for creating a reliable rabbit model of abdominal aortic aneurysm (AAA) via a combination of periaortic calcium chloride (CaCl2) and elastase incubation.
Forty-eight New Zealand white rabbits were divided into four groups. The AAA model was developed via a 20-minute periaortic incubation of CaCl2 (0.5 mol/L) and elastase (1 Unit/µL) in a 1.5-cm aortic segment (Group CE). A single incubation of CaCl2 (Group C) or elastase (Group E) and a sham operation group (Sham Group) were used for the controls. Diameter was measured by serial digital subtraction angiography imaging on days 5, 15 and 30. Animals were sacrificed on day 5 and day 30 for histopathological and immunohistochemical studies.
All animals in Group CE developed aneurysm, with an average dilation ratio of 65.3%±8.9% on day 5, 86.5%±28.7% on day 15 and 203.6%±39.1% on day 30. No aneurysm was found in Group C, and only one aneurysm was seen on day 5 in Group E. Group CE exhibited less intima-media thickness, endothelial recovery, elastin and smooth muscle cell (SMC) content, but stronger expression of matrix metalloproteinase-2, matrix metalloproteinase-9 and RAM11 compared to the controls.
The novel rabbit model of AAA created by using a combination of periaortic CaCl2 and elastase incubation is simple and effective to perform and is valuable for elucidating AAA mechanisms and therapeutic interventions in experimental studies.
PLoS ONE 07/2013; 8(7):e68476. DOI:10.1371/journal.pone.0068476 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The objective of this study was to determine the possibility of creating a novel animal model of abdominal aortic aneurysm (AAA) in rabbits by the periarterial application of papain.
Twelve New Zealand white rabbits were randomized into two groups: (1) the papain group, which received 2mg of papain (n=8) and (2) the control group, which received physiologic saline solution (n=4). A 1-cm aortic segment proximal to the bifurcation was isolated, and its adventitia was incubated with papain for 20 minutes. The rabbits underwent intravenous digital subtraction angiography (IVDSA) 5 and 21 days after the operation. The animals were then humanely killed for histomorphometric and immunohistochemical studies.
All animals in the papain group developed AAA, with an average aneurysm diameter of 4.0±0.6 and 4.1±0.4mm on days 5 and 21, respectively. No aneurysms were seen in the control group. On day 5, the papain-incubated aortas exhibited thinned and disorganized aortic walls, with decreased smooth muscle cells (SMCs) and fragmented and almost nonexistent elastic lamella. Media thickening, intimal hyperplasia, and smooth muscle cell regeneration were obvious on day 21. Immunostaining of matrix metalloproteinase (MMP)-9 and RAM11 showed strong expression in the papain group. On the contrary, the control group did not present histologic alterations and showed almost no expression of MMP-9 and RAM11.
A novel in vivo rabbit model of AAA can be induced through periarterial application of papain for 20 minutes. This model is similar to an elastase-induced aneurysm model and could be useful to clarify AAA pathogenesis and endovascular treatment intervention.
Journal of vascular and interventional radiology: JVIR 11/2012; 23(11):1529-36. DOI:10.1016/j.jvir.2012.08.007 · 2.15 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Low frequency and intensity ultrasound (LFU) sonication can selectively induce brain tumor cell apoptosis without damaging neural cells, while also enhancing drug delivery to brain tumors. To explore the underlying mechanisms of related pathways in LFU-induced apoptosis, we investigated the expression of proteins associated with LFU-induced apoptosis. C6 cells were used for in vitro experiments and C6 tumor-bearing rats were used during in vivo experiments. 3-[4.5-Dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide; thiazolyl blue (MTT) assay was used to detect C6 cell viability in vitro. Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) analysis was used to check the apoptotic cells, and they were counted and analyzed both in vitro and in vivo. Transmission electron microscopy (TEM) was used to illustrate the ultrastructure of apoptotic nuclei of cancer cells in vivo. The expressions of caspase-3, Bcl-2, and survivin proteins were assessed by immunofluorescence, immunohistochemistry and Western blot analysis in vivo. C6 cell viability decrease was statistically significant; the numbers of apoptotic C6 cells in the LFU sonication groups were higher than those in the control group both in vitro and in vivo. The expression of caspase-3 increased, yet the expressions of Bcl-2 and survivin decreased significantly 6h after LFU sonication, compared with the control group in vivo. This study suggests that LFU can induce apoptosis in vitro and in vivo, and that three signaling proteins, caspase-3, Bcl-2, and survivin, might be involved in LFU-induced apoptosis.
Brain research 07/2012; 1473:25-34. DOI:10.1016/j.brainres.2012.06.047 · 2.83 Impact Factor