Macroporous methacrylated hyaluronic acid hydrogel with different pore sizes for in vitro and in vivo evaluation of vascularization

Author(s):  
Daohuan Lu ◽  
Zhiwen Zeng ◽  
Zhijie Geng ◽  
Cuiping Guo ◽  
Dating Pei ◽  
...  

Abstract Vascularization of thick hydrogel scaffolds is still a big challenge, because the submicron- or nano-sized pores seriously restrict endothelial cells adhesion, proliferation and migration. Therefore, porous hydrogels have been fabricated as a kind of promising hydrous scaffolds for enhancing vascularization during tissue repairing. In order to investigate the effects of pore size on vascularization, macroporous methacrylated hyaluronic acid (HAMA) hydrogels with different pore sizes were fabricated by a gelatin microspheres (GMS) template method. After leaching out GMS templates, uniform and highly interconnected macropores were formed in hydrogels, which provided an ideal physical microenvironment to induce human umbilical vein endothelial cells (HUVECs) migration and tissue vascularization. In vitro results revealed that macroporous hydrogels facilitated cells proliferation and migration compared with non-macroporous hydrogels. Hydrogels with middle pore size of 200-250 μm (HAMA250 hydrogels) supported the best cell proliferation and furthest 3D migration of HUVECs. The influences of pore sizes on vascularization were then evaluated with subcutaneous embedding. In vivo results illustrated that HAMA250 hydrogels exhibited optimum vascularization behavior. Highest number of newly formed blood vessels and expression of CD31 could be found in HAMA250 hydrogels rather than in other hydrogels. In summary, our results concluded that the best pore size for endothelial cells migration and tissue vascularization was 200-250 μm. This research provides a new insight into the engineering vascularized tissues and may find utility in designing regenerative biomaterial scaffolds

2015 ◽  
Vol 113 (02) ◽  
pp. 319-328 ◽  
Author(s):  
Abdurazzag Abusnina ◽  
Thérèse Keravis ◽  
Qingwei Zhou ◽  
Hélène Justiniano ◽  
Annelise Lobstein ◽  
...  

SummaryVascular endothelial growth factor (VEGF) plays a major role in angiogenesis by stimulating endothelial cells. Increase in cyclic AMP (cAMP) level inhibits VEGF-induced endothelial cell proliferation and migration. Cyclic nucleotide phosphodiesterases (PDEs), which specifically hydrolyse cyclic nucleotides, are critical in the regulation of this signal transduction. We have previously reported that PDE2 and PDE4 up-regulations in human umbilical vein endothelial cells (HUVECs) are implicated in VEGF-induced angiogenesis and that inhibition of PDE2 and PDE4 activities prevents the development of the in vitro angiogenesis by increasing cAMP level, as well as the in vivo chicken embryo angiogenesis. We have also shown that polyphenols are able to inhibit PDEs. The curcumin having anti-cancer properties, the present study investigated whether PDE2 and PDE4 inhibitors and curcumin could have similar in vivo anti-tumour properties and whether the anti-angiogenic effects of curcumin are mediated by PDEs. Both PDE2/PDE4 inhibitor association and curcumin significantly inhibited in vivo tumour growth in C57BL/6N mice. In vitro, curcumin inhibited basal and VEGF-stimulated HUVEC proliferation and migration and delayed cell cycle progression at G0/G1, similarly to the combination of selective PDE2 and PDE4 inhibitors. cAMP levels in HUVECs were significantly increased by curcumin, similarly to rolipram (PDE4 inhibitor) and BAY-60–550 (PDE2 inhibitor) association, indicating cAMP-PDE inhibitions. Moreover, curcumin was able to inhibit VEGF-induced cAMP-PDE activity without acting on cGMP-PDE activity and to modulate PDE2 and PDE4 expressions in HUVECs. The present results suggest that curcumin exerts its in vitro anti-angiogenic and in vivo antitumour properties through combined PDE2 and PDE4 inhibition.


Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Michelle LeBlanc ◽  
Weiwen Wang ◽  
Feiye Guo ◽  
Chen Shen ◽  
Rui Chen ◽  
...  

Background: Endothelial ligands extrinsically regulate a broad spectrum of vascular functions with therapeutic potentials, but are traditionally identified on a case-by-case basis with technical challenges. We recently developed open reading frame phage display (OPD) for unbiased identification of phagocytosis ligands. In this study, we identified hepatoma-derived growth factor related protein-3 (HRP-3) as a putative endothelial ligand by OPD. We hypothesized that HRP-3 is a novel endothelial growth factor, capable of promoting endothelial cell (EC) growth and migration. Methods and Results: We performed 3 rounds of in vivo phage binding selection in mice with an OPD library, screened enriched phage clones by next generation DNA sequencing, and identified HRP-3 as one of the putative endothelial ligands. To confirm the finding, clonal phages displaying HRP-3, VEGF and GFP were generated and analyzed for their binding to human umbilical vein endothelial cells (HUVECs). The results show that HRP-3-Phage and VEGF-Phage had significantly higher binding to HUVECs than GFP-Phage. Functional analysis showed that purified recombinant HRP-3 significantly increased the proliferation of HUVECs at 24 and 48 h, whereas VEGF induced significant growth only at 48 h. Consistent with these findings, HRP-3 significantly stimulated cell proliferation by MTT assay. In vitro wound-healing assay indicated that both HRP-3 (500 ng/ml) and VEGF (50 ng/ml) significantly promoted the migration of HUVECs into the denuded area. To dissect the downstream signaling pathway, we demonstrated that HRP-3 significantly induced ERK1/2 phosphorylation in HUVECs after 10 min treatment. Similar effects of HRP-3 and VEGF on EC growth, migration, and ERK activation were also verified using human aorta endothelial cells. Conclusions: Our findings demonstrate that HRP-3 is a novel ligand, capable of promoting proliferation and migration of ECs. The pro-growth effect of HRP-3 is at least partially mediated through ERK pathway activation. These results in turn support the broad applicability of OPD for the systematic discovery of endothelial ligands.


2017 ◽  
Vol 95 (6) ◽  
pp. 697-707 ◽  
Author(s):  
In-Chul Lee ◽  
Jongdoo Kim ◽  
Jong-Sup Bae

The screening of bioactive compound libraries can be an effective approach for repositioning FDA-approved drugs or discovering new treatments for human diseases (drug repositioning). Drug repositioning refers to the development of existing drugs for new indications. Dabrafenib (DAB) is a B-Raf inhibitor and initially used for the treatment of metastatic melanoma therapy. Here, we tested the possible use of DAB in the treatment of lipopolysaccharide (LPS)-mediated vascular inflammatory responses. The anti-inflammatory activities of DAB were determined by measuring permeability, neutrophils adhesion and migration, and activation of pro-inflammatory proteins in LPS-activated human umbilical vein endothelial cells (HUVECs) and mice. We found that DAB inhibited LPS-induced barrier disruption, expression of cell adhesion molecules (CAMs), and adhesion and transendothelial migration of neutrophils to human endothelial cells. DAB also suppressed LPS-induced hyperpermeability and leukocytes migration in vivo. Furthermore, DAB suppressed the production of tumor necrosis factor-α (TNF-α) or interleukin (IL)-6 and the activation of nuclear factor-κB (NF-κB) or extracellular regulated kinases (ERK) 1/2 by LPS. Moreover, treatment with DAB resulted in reduced LPS-induced lethal endotoxemia. These results suggest that DAB possesses anti-inflammatory functions by inhibiting hyperpermeability, expression of CAMs, and adhesion and migration of leukocytes, thereby endorsing its usefulness as a therapy for vascular inflammatory diseases.


1997 ◽  
Vol 77 (05) ◽  
pp. 0975-0980 ◽  
Author(s):  
Angel Gálvez ◽  
Goretti Gómez-Ortiz ◽  
Maribel Díaz-Ricart ◽  
Ginés Escolar ◽  
Rogelio González-Sarmiento ◽  
...  

SummaryThe effect of desmopressin (DDAVP) on thrombogenicity, expression of tissue factor and procoagulant activity (PCA) of extracellular matrix (ECM) generated by human umbilical vein endothelial cells cultures (HUVEC), was studied under different experimental conditions. HUVEC were incubated with DDAVP (1, 5 and 30 ng/ml) and then detached from their ECM. The reactivity towards platelets of this ECM was tested in a perfusion system. Coverslips covered with DD A VP-treated ECMs were inserted in a parallel-plate chamber and exposed to normal blood anticoagulated with low molecular weight heparin (Fragmin®, 20 U/ml). Perfusions were run for 5 min at a shear rate of 800 s1. Deposition of platelets on ECMs was significantly increased with respect to control ECMs when DDAVP was used at 5 and 30 ng/ml (p <0.05 and p <0.01 respectively). The increase in platelet deposition was prevented by incubation of ECMs with an antibody against human tissue factor prior to perfusion. Immunofluorescence studies positively detected tissue factor antigen on DDAVP derived ECMs. A chromogenic assay performed under standardized conditions revealed a statistically significant increase in the procoagulant activity of the ECMs produced by ECs incubated with 30 ng/ml DDAVP (p <0.01 vs. control samples). Northern blot analysis revealed increased levels of tissue factor mRNA in extracts from ECs exposed to DDAVP. Our data indicate that DDAVP in vitro enhances platelet adhesion to the ECMs through increased expression of tissue factor. A similar increase in the expression of tissue factor might contribute to the in vivo hemostatic effect of DDAVP.


1997 ◽  
Vol 77 (06) ◽  
pp. 1182-1188 ◽  
Author(s):  
Ulrich M Vischer ◽  
Claes B Wollheinn

Summaryvon Willebrand factor (vWf) is released from endothelial cell storage granules after stimulation with thrombin, histamine and several other agents that induce an increase in cytosolic free calcium ([Ca2+]i). In vivo, epinephrine and the vasopressin analog DDAVP increase vWf plasma levels, although they are thought not to induce vWf release from endothelial cells in vitro. Since these agents act via a cAMP-dependent pathway in responsive cells, we examined the role of cAMP in vWf secretion from cultured human umbilical vein endothelial cells. vWf release increased by 50% in response to forskolin, which activates adenylate cyclase. The response to forskolin was much stronger when cAMP degradation was blocked with IBMX, an inhibitor of phosphodiesterases (+200%), whereas IBMX alone had no effect. vWf release could also be induced by the cAMP analogs dibutyryl-cAMP (+40%) and 8-bromo-cAMP (+25%); although their effect was weak, they clearly potentiated the response to thrombin. Epinephrine (together with IBMX) caused a small, dose-dependent increase in vWf release, maximal at 10-6 M (+50%), and also potentiated the response to thrombin. This effect is mediated by adenylate cyclase-coupled β-adrenergic receptors, since it is inhibited by propranolol and mimicked by isoproterenol. In contrast to thrombin, neither forskolin nor epinephrine caused an increase in [Ca2+]j as measured by fura-2 fluorescence. In addition, the effects of forskolin and thrombin were additive, suggesting that they act through distinct signaling pathways. We found a close correlation between cellular cAMP content and vWf release after stimulation with epinephrine and forskolin. These results demonstrate that cAMP-dependent signaling events are involved in the control of exocytosis from endothelial cells (an effect not mediated by an increase in [Ca2+]i) and provide an explanation for epinephrine-induced vWf release.


2019 ◽  
Vol 17 (4) ◽  
pp. 379-387 ◽  
Author(s):  
Yan Sun ◽  
Xiao-li Liu ◽  
Dai Zhang ◽  
Fang Liu ◽  
Yu-jing Cheng ◽  
...  

Background:Intraplaque angiogenesis, the process of generating new blood vessels mediated by endothelial cells, contributes to plaque growth, intraplaque hemorrhage, and thromboembolic events. Platelet-derived Exosomes (PLT-EXOs) affect angiogenesis in multiple ways. The ability of miR-126, one of the best-characterized miRNAs that regulates angiogenesis, carried by PLT-EXOs to influence angiogenesis via the regulation of the proliferation and migration of endothelial cells is unknown. In this study, we aimed to investigate the effects of PLT-EXOs on angiogenesis by Human Umbilical Vein Endothelial Cells (HUVECs).Methods:We evaluated the levels of miR-126 and angiogenic factors in PLT-EXOs from Acute Coronary Syndrome (ACS) patients and healthy donors by real-time Polymerase Chain Reaction (PCR) and western blotting. We incubated HUVECs with PLT-EXOs and measured cell proliferation and migration with the Cell Counting Kit-8 assay and scratch assay, respectively. We also investigated the expression of miR-126 and angiogenic factors in HUVECs after exposure to PLT-EXOs by western blotting and real-time PCR.Results:PLT-EXOs from ACS patients contained higher levels of miR-126 and angiogenic factors, including Vascular Endothelial Growth Factor (VEGF), basic Fibroblast Growth Factor (bFGF), and Transforming Growth Factor Beta 1 (TGF-β1), than those from healthy donors (p<0.05). Moreover, the levels of exosomal miR-126 and angiogenic factors were increased after stimulation with thrombin (p<0.01). HUVEC proliferation and migration were promoted by treatment with activated PLT-EXOs (p<0.01); they were accompanied by the over-expression of miR-126 and angiogenic factors, including VEGF, bFGF, and TGF-β1 (p<0.01).Conclusion:Activated PLT-EXOs promoted the proliferation and migration of HUVECs, and the overexpression of miR-126 and angiogenic factors, thereby elucidating potential new therapeutic targets for intraplaque angiogenesis.


2021 ◽  
Vol 12 (4) ◽  
Author(s):  
Jianye Xu ◽  
Jian Zhang ◽  
Zongpu Zhang ◽  
Zijie Gao ◽  
Yanhua Qi ◽  
...  

AbstractExosomes participate in intercellular communication and glioma microenvironment modulation, but the exact mechanisms by which glioma-derived exosomes (GDEs) promote the generation of the immunosuppressive microenvironment are still unclear. Here, we investigated the effects of GDEs on autophagy, the polarization of tumor-associated macrophages (TAMs), and glioma progression. Compared with normoxic glioma-derived exosomes (N-GDEs), hypoxic glioma-derived exosomes (H-GDEs) markedly facilitated autophagy and M2-like macrophage polarization, which subsequently promoted glioma proliferation and migration in vitro and in vivo. Western blot and qRT-PCR analyses indicated that interleukin 6 (IL-6) and miR-155-3p were highly expressed in H-GDEs. Further experiments showed that IL-6 and miR-155-3p induced M2-like macrophage polarization via the IL-6-pSTAT3-miR-155-3p-autophagy-pSTAT3 positive feedback loop, which promotes glioma progression. Our study clarifies a mechanism by which hypoxia and glioma influence autophagy and M2-like macrophage polarization via exosomes, which could advance the formation of the immunosuppressive microenvironment. Our findings suggest that IL-6 and miR-155-3p may be novel biomarkers for diagnosing glioma and that treatments targeting autophagy and the STAT3 pathway may contribute to antitumor immunotherapy.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Zhenghui Cheng ◽  
Yawen Zhang ◽  
Yinchao Tian ◽  
Yuhan Chen ◽  
Fei Ding ◽  
...  

Abstract Background Schwann cells (SCs) play a crucial role in the repair of peripheral nerves. This is due to their ability to proliferate, migrate, and provide trophic support to axon regrowth. During peripheral nerve injury, SCs de-differentiate and reprogram to gain the ability to repair nerves. Cysteine-rich 61 (Cyr61/CCN1) is a member of the CCN family of matrix cell proteins and have been reported to be abundant in the secretome of repair mediating SCs. In this study we investigate the function of Cyr61 in SCs. Results We observed Cyr61 was expressed both in vivo and in vitro. The promoting effect of Cyr61 on SC proliferation and migration was through autocrine and paracrine mechanisms. SCs expressed αvβ3 integrin and the effect of Cyr61 on SC proliferation and migration could be blocked via αvβ3 integrin. Cyr61 could influence c-Jun protein expression in cultured SCs. Conclusions In this study, we found that Cyr61 promotes SC proliferation and migration via αvβ3 integrin and regulates c-Jun expression. Our study contributes to the understanding of cellular and molecular mechanisms underlying SC’s function during nerve injury, and thus, may facilitate the regeneration of peripheral nerves after injury.


Author(s):  
Susan Gallogly ◽  
Takeshi Fujisawa ◽  
John D. Hung ◽  
Mairi Brittan ◽  
Elizabeth M. Skinner ◽  
...  

Abstract Purpose Endothelial dysfunction is central to the pathogenesis of acute coronary syndrome. The study of diseased endothelium is very challenging due to inherent difficulties in isolating endothelial cells from the coronary vascular bed. We sought to isolate and characterise coronary endothelial cells from patients undergoing thrombectomy for myocardial infarction to develop a patient-specific in vitro model of endothelial dysfunction. Methods In a prospective cohort study, 49 patients underwent percutaneous coronary intervention with thrombus aspiration. Specimens were cultured, and coronary endothelial outgrowth (CEO) cells were isolated. CEO cells, endothelial cells isolated from peripheral blood, explanted coronary arteries, and umbilical veins were phenotyped and assessed functionally in vitro and in vivo. Results CEO cells were obtained from 27/37 (73%) atherothrombotic specimens and gave rise to cells with cobblestone morphology expressing CD146 (94 ± 6%), CD31 (87 ± 14%), and von Willebrand factor (100 ± 1%). Proliferation of CEO cells was impaired compared to both coronary artery and umbilical vein endothelial cells (population doubling time, 2.5 ± 1.0 versus 1.6 ± 0.3 and 1.2 ± 0.3 days, respectively). Cell migration was also reduced compared to umbilical vein endothelial cells (29 ± 20% versus 85±19%). Importantly, unlike control endothelial cells, dysfunctional CEO cells did not incorporate into new vessels or promote angiogenesis in vivo. Conclusions CEO cells can be reliably isolated and cultured from thrombectomy specimens in patients with acute coronary syndrome. Compared to controls, patient-derived coronary endothelial cells had impaired capacity to proliferate, migrate, and contribute to angiogenesis. CEO cells could be used to identify novel therapeutic targets to enhance endothelial function and prevent acute coronary syndromes.


2021 ◽  
Vol 12 (5) ◽  
Author(s):  
Chenjing Zhang ◽  
Xiaolu Zhou ◽  
Xiaoge Geng ◽  
Yu Zhang ◽  
Jingya Wang ◽  
...  

AbstractDysregulation of circular RNA (circRNA) expression is involved in the progression of cancer. Here, we aimed to study the potential function of hsa_circ_0006401 in colorectal cancer (CRC). CircRNA hsa_circ_0006401 expression levels in CRC and adjacent nontumor tissues were analyzed by real-time quantitative PCR (qRT-PCR) and circRNA in situ hybridization (RNA-ISH). Then, CRC cell proliferation was assessed by cell counting. Wound-healing and transwell assays were utilized to detect the effect of hsa_circ_0006401 on CRC migration. A circRNA-ORF construct was created, and a specific antibody against the splice junction of hsa_circ_0006401 was prepared. Finally, the proteins directly binding to hsa_circ_0006401 peptides were identified by immunoprecipitation combined with mass spectrometry. In our study, we found hsa_circ_0006401 was closely related to CRC metastasis and exhibited upregulated expression in metastatic CRC tissue samples. Proliferation and migration were inhibited in vitro when hsa_circ_0006401 expression was silenced. Downregulation of hsa_circ_0006401 expression decreased CRC proliferation and liver metastasis in vivo. A 198-aa peptide was encoded by sequences of the splice junction absent from col6a3. Hsa_circ_0006401 promoted CRC proliferation and migration by encoding the hsa_circ_0006401 peptide. Hsa_circ_0006401 peptides decreased the mRNA and protein level of the host gene col6a3 by promoting col6a3 mRNA stabilation. In conclusion, our study revealed that circRNAs generated from col6a3 that contain an open-reading frame (ORF) encode a novel 198-aa functional peptide and hsa_circ_0006401 peptides promote stability of the host gene col6a3 mRNA to promote CRC proliferation and metastasis.


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