Non-Specific Endothelial Cell Interactions With the Substrate Result in Cell Activation and Angiogenesis In Vitro

Author(s):  
Hongkwan Cho ◽  
Abdul Sheikh ◽  
Daria A. Narmoneva

Vascularization is critical for success of tissue engineering applications. Previous studies by us and others have shown that self-assembling peptide nanoscaffold RAD16-II promotes de novo capillary formation (angiogenesis) in vitro and neovascularization in vivo, and is a promising material for tissue engineering applications [1, 2]. However, the molecular mechanisms for cell interactions with this material are not known. Angiogenesis is mediated via interactions between integrins, which are expressed on the surface of activated endothelial cells (ECs), and extracellular matrix proteins. Among several integrins, αvβ3 is the most abundant and influential receptor regulating angiogenesis [3]. The αvβ3 integrin binds to its ligands via Arg-Gly-Asp (RGD) biding motif. However, there are no RGD motifs on RAD 16-II peptide. Instead, it contains three RAD motifs. Studies have shown that non-specific binding of αvβ3 with RAD can be retained through R and D sides [4]. The objective of this study, therefore, is to elucidate the underlying molecular mechanisms of RAD16-II nanoscaffold interactions with microvascular endothelial cells. We hypothesize that non-specific interactions between RAD16-II peptide nanoscaffold and αvβ3 integrin result in phosphorylations of β3 cytoplasmic domain, which then activate downstream angiogenic signaling pathways and promote angiogenesis.

Blood ◽  
1994 ◽  
Vol 83 (5) ◽  
pp. 1174-1178 ◽  
Author(s):  
NW Lukacs ◽  
RM Strieter ◽  
VM Elner ◽  
HL Evanoff ◽  
M Burdick ◽  
...  

Abstract The extravasation of leukocytes from the lumen of the vessel to a site of inflammation initially requires a specific binding event followed by migration of the cells through the endothelial cell layer into the inflammatory foci. The interaction of leukocytes with the endothelium via specific receptors may provide intracellular signals that activate the cells. In the present study we have investigated the production of MIP-1 alpha, a mononuclear cell chemotactic protein, during monocyte:endothelial cell interactions. Neither unstimulated nor interferon (IFN)-stimulated human umbilical vein endothelial cells (HUVECs) produced substantial MIP-1 alpha protein. However, the addition of enriched monocyte populations with unstimulated HUVECs resulted in the production of MIP-1 alpha. Monocytes cultured with IFN- gamma-activated HUVECs showed an additional increase in MIP-1 alpha production. Immunohistochemical analysis demonstrated that the monocyte was the cellular source of MIP-1 alpha production in this coculture system. The mechanism of MIP-1 alpha expression was further assessed by determining the role of adhesion molecules in the regulation of MIP-1 alpha production during monocyte:HUVEC interactions. To attenuate the increased production of MIP-1 alpha by the monocyte:HUVEC interaction, anti-adhesion molecule monoclonal antibodies (MoAbs) were added to the cultures. Addition of anti-ICAM-1 neutralizing MoAbs significantly inhibited the production of MIP-1 alpha, whereas neutralizing anti-VCAM- 1 MoAbs failed to block MIP-1 alpha production. Furthermore, MIP-1 alpha production was induced in monocytes cultured on ICAM-1-coated plates. These results indicate an intimate relationship between leukocyte-endothelial cells, adhesion molecule, and the expression of the monocyte-derived chemokine MIP-1 alpha during cellular adhesion. This mechanism may serve an important role in cell activation and recruitment of leukocytes during the initiation of an inflammatory response.


Blood ◽  
1994 ◽  
Vol 83 (5) ◽  
pp. 1174-1178
Author(s):  
NW Lukacs ◽  
RM Strieter ◽  
VM Elner ◽  
HL Evanoff ◽  
M Burdick ◽  
...  

The extravasation of leukocytes from the lumen of the vessel to a site of inflammation initially requires a specific binding event followed by migration of the cells through the endothelial cell layer into the inflammatory foci. The interaction of leukocytes with the endothelium via specific receptors may provide intracellular signals that activate the cells. In the present study we have investigated the production of MIP-1 alpha, a mononuclear cell chemotactic protein, during monocyte:endothelial cell interactions. Neither unstimulated nor interferon (IFN)-stimulated human umbilical vein endothelial cells (HUVECs) produced substantial MIP-1 alpha protein. However, the addition of enriched monocyte populations with unstimulated HUVECs resulted in the production of MIP-1 alpha. Monocytes cultured with IFN- gamma-activated HUVECs showed an additional increase in MIP-1 alpha production. Immunohistochemical analysis demonstrated that the monocyte was the cellular source of MIP-1 alpha production in this coculture system. The mechanism of MIP-1 alpha expression was further assessed by determining the role of adhesion molecules in the regulation of MIP-1 alpha production during monocyte:HUVEC interactions. To attenuate the increased production of MIP-1 alpha by the monocyte:HUVEC interaction, anti-adhesion molecule monoclonal antibodies (MoAbs) were added to the cultures. Addition of anti-ICAM-1 neutralizing MoAbs significantly inhibited the production of MIP-1 alpha, whereas neutralizing anti-VCAM- 1 MoAbs failed to block MIP-1 alpha production. Furthermore, MIP-1 alpha production was induced in monocytes cultured on ICAM-1-coated plates. These results indicate an intimate relationship between leukocyte-endothelial cells, adhesion molecule, and the expression of the monocyte-derived chemokine MIP-1 alpha during cellular adhesion. This mechanism may serve an important role in cell activation and recruitment of leukocytes during the initiation of an inflammatory response.


Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1374 ◽  
Author(s):  
Mahboobeh Rezaeeyazdi ◽  
Thibault Colombani ◽  
Adnan Memic ◽  
Sidi Bencherif

Polymeric scaffolds such as hydrogels can be engineered to restore, maintain, or improve impaired tissues and organs. However, most hydrogels require surgical implantation that can cause several complications such as infection and damage to adjacent tissues. Therefore, developing minimally invasive strategies is of critical importance for these purposes. Herein, we developed several injectable cryogels made out of hyaluronic acid and gelatin for tissue-engineering applications. The physicochemical properties of hyaluronic acid combined with the intrinsic cell-adhesion properties of gelatin can provide suitable physical support for the attachment, survival, and spreading of cells. The physical characteristics of pure gelatin cryogels, such as mechanics and injectability, were enhanced once copolymerized with hyaluronic acid. Reciprocally, the adhesion of 3T3 cells cultured in hyaluronic acid cryogels was enhanced when formulated with gelatin. Furthermore, cryogels had a minimal effect on bone marrow dendritic cell activation, suggesting their cytocompatibility. Finally, in vitro studies revealed that copolymerizing gelatin with hyaluronic acid did not significantly alter their respective intrinsic biological properties. These findings suggest that hyaluronic acid-co-gelatin cryogels combined the favorable inherent properties of each biopolymer, providing a mechanically robust, cell-responsive, macroporous, and injectable platform for tissue-engineering applications.


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.


2010 ◽  
Vol 19 (4) ◽  
pp. 096369351001900 ◽  
Author(s):  
A. Hamlekhan ◽  
M. Mozafari ◽  
N. Nezafati ◽  
M. Azami ◽  
H. Hadipour

In this study, poly(∊-caprolactone) (PCL), gelatin (GEL) and nanocrystalline hydroxyapatite (HAp) was applied to fabricate novel PCL-GEL-HAp nanaocomposite scaffolds through a new fabrication method. With the aim of finding the best fabrication method, after testing different methods and solvents, the best method and solvents were found, and the nanocomposites were prepared through layer solvent casting combined with freeze-drying. Acetone and distillated water were used as the PCL and GEL solvents, respectively. The mechanical test showed that the increasing of the PCL weight through the scaffolds caused the improvement of the final nanocomposite mechanical behavior due to the increasing of the ultimate stress, stiffness and elastic modulus (8 MPa for 0% wt PCL to 23.5 MPa for 50% wt PCL). The biomineralization investigation of the scaffolds revealed the formation of bone-like apatite layers after immersion in simulated body fluid (SBF). In addition, the in vitro cytotoxity of the scaffolds using L929 mouse fibroblast cell line (ATCC) indicated no sign of toxicity. These results indicated that the fabricated scaffold possesses the prerequisites for bone tissue engineering applications.


Marine Drugs ◽  
2021 ◽  
Vol 19 (2) ◽  
pp. 85 ◽  
Author(s):  
Truc Cong Ho ◽  
Jin-Seok Park ◽  
Sung-Yeoul Kim ◽  
Hoyeol Lee ◽  
Ju-Sop Lim ◽  
...  

For tissue engineering applications, biodegradable scaffolds containing high molecular weights (MW) of collagen and sodium alginate have been developed and characterized. However, the properties of low MW collagen-based scaffolds have not been studied in previous research. This work examined the distinctive properties of low MW collagen-based scaffolds with alginate unmodified and modified by subcritical water. Besides, we developed a facile method to cross-link water-soluble scaffolds using glutaraldehyde in an aqueous ethanol solution. The prepared cross-linked scaffolds showed good structural properties with high porosity (~93%) and high cross-linking degree (50–60%). Compared with collagen (6000 Da)-based scaffolds, collagen (25,000 Da)-based scaffolds exhibited higher stability against collagenase degradation and lower weight loss in phosphate buffer pH 7.4. Collagen (25,000 Da)-based scaffolds with modified alginate tended to improve antioxidant capacity compared with scaffolds containing unmodified alginate. Interestingly, in vitro coagulant activity assay demonstrated that collagen (25,000 Da)-based scaffolds with modified alginate (C25-A63 and C25-A21) significantly reduced the clotting time of human plasma compared with scaffolds consisting of unmodified alginate. Although some further investigations need to be done, collagen (25,000 Da)-based scaffolds with modified alginate should be considered as a potential candidate for tissue engineering applications.


Author(s):  
Kivilcim Buyukhatipoglu ◽  
Robert Chang ◽  
Wei Sun ◽  
Alisa Morss Clyne

Tissue engineering may require precise patterning of cells and bioactive components to recreate the complex, 3D architecture of native tissue. However, it is difficult to image and track cells and bioactive factors once they are incorporated into the tissue engineered construct. These bioactive factors and cells may also need to be moved during tissue growth in vitro or after implantation in vivo to achieve the desired tissue properties, or they may need to be removed entirely prior to implantation for biosafety concerns.


2017 ◽  
Vol 14 (2) ◽  
pp. 128-135 ◽  
Author(s):  
Yongsong Liu ◽  
Hong Sun ◽  
Min Hu ◽  
Min Zhu ◽  
Sean Tighe ◽  
...  

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