scholarly journals A new microcirculation culture method with a self-organized capillary network

2020 ◽  
Author(s):  
Kei Sugihara ◽  
Yoshimi Yamaguchi ◽  
Shiori Usui ◽  
Yuji Nashimoto ◽  
Sanshiro Hanada ◽  
...  

AbstractA lack of microcirculation has been one of the most significant obstacles for three-dimensional culture systems of organoids and embryonic tissues. Here, we developed a simple and reliable method to implement a perfusable capillary network in vitro. The method employed the self-organization of endothelial cells to generate a capillary network and a static pressure difference for culture medium circulation, which can be easily introduced to standard biological laboratories and enables long-term cultivation of vascular structures. Using this culture system, we perfused the lumen of the self-organized capillary network and observed a flow-induced vascular remodeling process, cell shape changes, and collective cell migration. We also observed an increase in cell proliferation around the synthetic vasculature induced by flow, indicating functional perfusion of the culture medium. We also reconstructed extravasation of tumor and inflammatory cells, and circulation inside spheroids including endothelial cells and human lung fibroblasts. In conclusion, this system is a promising tool to elucidate the mechanisms of various biological processes related to vascular flow.

2008 ◽  
Vol 295 (1) ◽  
pp. H174-H184 ◽  
Author(s):  
Katherine A. Radek ◽  
Elizabeth J. Kovacs ◽  
Richard L. Gallo ◽  
Luisa A. DiPietro

Physiological angiogenesis is regulated by various factors, including signaling through vascular endothelial growth factor (VEGF) receptors. We previously reported that a single dose of ethanol (1.4 g/kg), yielding a blood alcohol concentration of 100 mg/dl, significantly impairs angiogenesis in murine wounds, despite adequate levels of VEGF, suggesting direct effects of ethanol on endothelial cell signaling (40). To examine the mechanism by which ethanol influences angiogenesis in wounds, we employed two different in vitro angiogenesis assays to determine whether acute ethanol exposure (100 mg/dl) would have long-lasting effects on VEGF-induced capillary network formation. Ethanol exposure resulted in reduced VEGF-induced cord formation on collagen and reduced capillary network structure on Matrigel in vitro. In addition, ethanol exposure decreased expression of endothelial VEGF receptor-2, as well as VEGF receptor-2 phosphorylation in vitro. Inhibition of ethanol metabolism by 4-methylpyrazole partially abrogated the effect of ethanol on endothelial cell cord formation. However, mice treated with t-butanol, an alcohol not metabolized by alcohol dehydrogenase, exhibited no change in wound vascularity. These results suggest that products of ethanol metabolism are important factors in the development of ethanol-induced changes in endothelial cell responsiveness to VEGF. In vivo, ethanol exposure caused both decreased angiogenesis and increased hypoxia in wounds. Moreover, in vitro experiments demonstrated a direct effect of ethanol on the response to hypoxia in endothelial cells, as ethanol diminished nuclear hypoxia-inducible factor-1α protein levels. Together, the data establish that acute ethanol exposure significantly impairs angiogenesis and suggest that this effect is mediated by changes in endothelial cell responsiveness to both VEGF and hypoxia.


Viruses ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2355
Author(s):  
Alexis Aguiar ◽  
Melissa Galinato ◽  
Maite’ Bradley Silva ◽  
Bryant Toth ◽  
Michael A. McVoy ◽  
...  

Only a handful of cell types, including fibroblasts, epithelial, and endothelial cells, can support human cytomegalovirus (CMV) replication in vitro, in striking contrast to the situation in vivo. While the susceptibility of epithelial and endothelial cells to CMV infection is strongly modulated by their anatomical site of origin, multiple CMV strains have been successfully isolated and propagated on fibroblasts derived from different organs. As oral mucosal cells are likely involved in CMV acquisition, we sought to evaluate the ability of infant labial fibroblasts to support CMV replication, compared to that of commonly used foreskin and fetal lung fibroblasts. No differences were found in the proportion of cells initiating infection, or in the amounts of viral progeny produced after exposure to the fibroblast-adapted CMV strain AD169 or to the endothelial cell-adapted strain TB40/E. Syncytia formation was, however, significantly enhanced in infected labial and lung fibroblasts compared to foreskin-derived cells, and did not occur after infection with AD169. Together, these data indicate that fibroblast populations derived from different tissues are uniformly permissive to CMV infection but retain phenotypic differences of potential importance for infection-induced cell–cell fusion, and ensuing viral spread and pathogenesis in different organs.


1979 ◽  
Author(s):  
W.E. Laug

Cloned endothelial cells obtained from the aorta of 1-2 day old calves produced high fibrinolytic activity, which was 90% dependent upon the presence of plasminogen when grown on 125 I fibrin coated dishes. High plasminogen-dependent proteolytic activity was also demonstrated in the cell lysate and in the culture medium of the cells. The production and secretion of this prtitease were found to increase during the log phase of cell growth and to reach a maximum at con fluency. Thereafter they remained constantly high. This protease, partially purified from the culture medium of confluent endothelial cell cultures, is aiginine specific and activates plasminogen by piOteolytic cleavage to plasmin. Its proteolytic activity which is highest in the pH range of 7.5 to 8.0 is irreversibly inhibited by diisopropyl fluorophosphate, suggesting that it is a serine protease. The molecular weight of this protease is approximately S2000.


2019 ◽  
Vol 31 (1) ◽  
pp. 172
Author(s):  
T. Yamanouchi ◽  
H. Matsuda ◽  
K. Ogata ◽  
Y. Hashiyada

In vitro-produced (IVP) embryos are more easily damaged by cryopreservation than in vivo-derived embryos. Therefore, transportation of fresh IVP embryos in a manner that can maintain viability is necessary. This study was conducted to determine the preferable culture conditions for transport of embryos at 5 days post-insemination (dpi) in 1.5-mL microtubes. Cumulus-oocyte complexes derived from an abattoir were matured and then inseminated with frozen-thawed semen. Presumptive zygotes were cultured in mCR1aa (CR1)+5% calf serum (CS) until use. In Exp. 1, embryos with 5 blastomeres at 5 dpi were randomly assigned to 1 of 3 groups: 25mM Hepes-CR1aa (H-CR1)+5% CS or 25mM Hepes-M199 (H-M199)+5% CS in air, or CR1 in 5% CO2. Embryos were cultured in microdrops overlaid with liquid paraffin in a petri dish for 48h at 38.5°C. In Exp. 2, the optimal number of embryos to culture per microtube was assessed. Presumptive zygotes were cultured in groups of 20, 40, or 80 in 1mL of CR1 covered with liquid paraffin in microtubes in an incubator at 38.5°C in 5% CO2 until 7 dpi. For Exp. 3, culture of embryos in microtubes in a portable incubator was tested. At 5 dpi, 5-cell embryos (n=17 to 36 per microtube) were statically cultured in 1mL of CR1 or H-CR1 in microtubes in a portable incubator set at 38.5°C for 48h. The CR1 was pre-equilibrated in an incubator in 5% CO2 for 24h before use. Embryos were harvested from microtubes after 48h and were then cultured in microdrops of CR1 overlaid with liquid paraffin in a petri dish in an incubator at 38.5°C in 5% CO2 until 8 dpi. In Exp. 4, embryos (n=29 to 39 five-cell embryos per microtube) were transported in a portable incubator by land for 1000km over a period of 44h using the same conditions as in Exp. 3. Control embryos were statically cultured in microdrops of CR1 in an incubator in 5% CO2. Statistical analyses were carried out by ANOVA (Exp. 1 and 2), t-test (Exp. 3), or Fisher’s exact test (Exp. 4). In Exp. 1, there was no effect (P>0.05) of culture medium on blastocyst development at 7 dpi (27.6±2.3, 25.7±7.2, and 17.3±2.9% for CR1, H-CR1, and H-M199, respectively). In Exp. 2, blastocyst development at 7 dpi was not affected (P>0.05) by the number of presumptive zygotes cultured per microtube (43.6±8.3, 42.4±4.0, and 39.9±2.9% for 20, 40, and 80 presumptive zygotes, respectively). In Exp. 3, blastocyst development at 8 dpi was not affected (P>0.05) by culture medium (60.7±7.4 and 53.1±4.4% for CR1 and H-CR1, respectively); however, the pH of CR1 changed from 7.5 to 8.1 at 48h after culture. In Exp. 4, blastocyst development at 8 dpi was not affected (P>0.05) by transport (57.1, 64.4, and 75.5% for CR1, H-CR1, and control, respectively). These results indicate that IVP embryos harvested at 5 dpi can be transported by portable incubator with no effect on embryo development to the blastocyst stage. This work was supported by grants from the Project of the Bio-oriented Technology Research Advancement Institution, NARO (the special scheme project on advanced research and the development for next-generation technology).


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Takafumi Matsumura ◽  
Takuya Sato ◽  
Takeru Abe ◽  
Hiroyuki Sanjo ◽  
Kumiko Katagiri ◽  
...  

AbstractIn vitro spermatogenesis (IVS) using air–liquid interphase organ culture method is possible with mouse testis tissues. The same method, however, has been hardly applicable to animals other than mice, only producing no or limited progression of spermatogenesis. In the present study, we challenged IVS of rats with modifications of culture medium, by supplementing chemical substances, including hormones, antioxidants, and lysophospholipids. In addition, reducing oxygen tension by placing tissues in an incubator of lower oxygen concentration and/or applying silicone cover ceiling on top of the tissue were effective for improving the spermatogenic efficiency. Through these modifications of the culture condition, rat spermatogenesis up to round spermatids was maintained over 70 days in the cultured tissue. Present results demonstrated a significant progress in rat IVS, revealing conditions commonly favorable for mice and rats as well as finding rat-specific optimizations. This is an important step towards successful IVS in many animal species, including humans.


Author(s):  
Ogechi Ogoke ◽  
Osama Yousef ◽  
Cortney Ott ◽  
Allison Kalinousky ◽  
Wayne Lin ◽  
...  

Three-dimensional (3D) collective cell migration (CCM) is critical for improving liver cell therapies, eliciting mechanisms of liver disease, and modeling human liver development and organogenesis. Mechanisms of CCM differ in 2D vs. 3D systems, and existing models are limited to 2D or transwell-based systems, suggesting there is a need for improved 3D models of CCM. To recreate liver 3D CCM, we engineered in vitro 3D models based upon a morphogenetic transition that occurs during liver organogenesis, which occurs rapidly between E8.5 and E9.5 (mouse). During this morphogenetic transition, 3D CCM exhibits co-migration (multiple cell types), thick-strand interactions with surrounding septum transversum mesenchyme (STM), branching morphogenesis, and 3D interstitial migration. Here, we engineer several 3D in vitro culture systems, each of which mimics one of these processes in vitro. In mixed spheroids bearing both liver cells and uniquely MRC-5 (fetal lung) fibroblasts, we observed evidence of co-migration, and a significant increase in length and number of liver spheroid protrusions, which was highly sensitive to transforming growth factor beta 1 (TGFβ1) stimulation. In MRC-5-conditioned medium (M-CM) experiments, we observed dose-dependent branching morphogenesis associated with an upregulation of Twist1, which was inhibited by a broad TGFβ inhibitor. In models in which liver spheroids and MRC-5 spheroids were co-cultured, we observed complex strand morphogenesis, whereby thin, linear, 3D liver cell strands attach to the MRC-5 spheroid, anchor and thicken to form permanent and thick anchoring contacts between the two spheroids. In these spheroid co-culture models, we also observed spheroid fusion and strong evidence for interstitial migration. In conclusion, we present several novel cultivation systems that recreate distinct features of liver 3D CCM. These methodologies will greatly improve our molecular, cellular, and tissue-scale understanding of liver organogenesis, liver diseases like cancer, and liver cell therapy, and will also serve as a tool to bridge conventional 2D studies and preclinical in vivo studies.


2013 ◽  
Vol 6 (273) ◽  
pp. ec99-ec99 ◽  
Author(s):  
Nancy R. Gough

New blood vessels form from existing ones through a process called angiogenesis. Excessive or impaired angiogenesis contribute to various diseases, including cancer and diabetic retinopathy (excessive angiogenesis) or diabetic foot ulcers and impaired wound healing (impaired angiogenesis). Thus, drugs that can influence this morphogenetic process are clinically important; however, the currently available methods to assay the effects of such drugs are limited. Nguyen et al. developed a three-dimensional platform consisting of two cylindrical channels in a collagen matrix. Into one channel, endothelial cells were injected and formed a “parent” vessel through which medium was perfused; into the other channel, various pro- or anti-angiogenic cocktails were perfused, creating a gradient through the intervening matrix. Introduction individually of vascular endothelial growth factor (VEGF), hepatocyte growth factor (HGF), basic fibroblast growth factor (bFGF), or monocyte chemotactic protein-1 (MCP-1) failed to stimulate invasion of endothelial cells into the matrix, but introduction of sphingosine 1-phosphate (S1P) or the phorbol ester PMA stimulated migration of single cells (S1P) or collective cell migration (PMA). Two different cocktails containing combinations of these factors stimulated angiogenic sprouting that ultimately resulted in an endothelial lining of the factor-delivery channel and microvessels connecting the two channels. The integrity of the connected vessels was confirmed by tracking beads introduced into the vessels. Analysis of the morphological characteristics of the newly sprouting vessels confirmed that they recapitulated in vivo events, such as the formation of filopodia-extending tip cells and polarized stalk cells. Although introduction of either a VEGF inhibitor or an inhibitor of the S1P receptor blocked angiogenesis, examination of the morphological characteristics revealed differential effects on sprouting that depended on the inhibitor and the growth factor cocktail into which the inhibitor was introduced. Thus, this system could be useful in exploring mechanisms that regulate various steps in the angiogenic process and in screening for factors or drugs that alter this complex process.D.-H. T. Nguyen, S. C. Stapleton, M. T. Yang, S. S. Cha, C. K. Choi, P. A. Galie, C. S. Chen, Biomimetic model to reconstitute angiogenic sprouting morphogenesis in vitro. Proc. Natl. Acad. Sci. U.S.A.110, 6712–6717 (2013). [Abstract][Full Text]


Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 2614-2614
Author(s):  
Gunter Schuch ◽  
Suleyman Erguen ◽  
Shay Soker ◽  
Dieter K. Hossfeld ◽  
Walter Fiedler

Abstract INTRODUCTION: Acute lung injury is a severe condition developing in patients with acute sepsis characterized by lung edema with extravasation of plasma proteins, infiltration by inflammatory cells and pulmonary hemorrhage. Vascular endothelial growth factor (VEGF), also known as vascular permeability factor, is known to not only promote angiogenesis but also increase vascular permeability and has been linked to pathological conditions like retinopathy and acute lung injury. Patients with sepsis and acute lung injury have increased VEGF levels in their plasma. As shown recently, mice treated with VEGF develop histological changes comparable to acute lung injury in septic patients. Endostatin (ES), a endogenous inhibitor of angiogenesis, has been shown to inhibit tumor growth in various models. The mechanisms by which ES inhibits endothelial cell proliferation and function are not clear, yet. It was proposed that one mechanism is the inhibition of VEGF-induced activation of VEGF receptor 2 (VEGFR-2). This study was performed in order to examine whether ES may antagonize VEGF-induced effects leading to increased permeability and lung injury. METHODS: We established an in vitro permeability model using transwell chambers with human dermal microvascular endothelial cells (HDMEC) seeded in the upper chamber on a porous membrane. VEGF-induced permeability was determined by measuring methylene blue to the lower chamber. In order to test the effect of ES on VEGFR-2 activation porcine aortic endothelial cells expressing human VEGFR-2 were incubated with 50 ng/ml VEGF with or without 5 ug/ml ES for 30 min ice. Cell lysate was precipitated with conacavalin A, separated by SDS-PAGE, blotted and analyzed for KDR phosphorylation using phosphotyrosine specific and KDR antibodies. We generated cells with strong expresssion of either VEGF or mouse ES. The cells were encapsulated in alginate beads and injected s.c. to SCID mice divided in the following groups: A) control, B) VEGF, C) ES, D) VEGF + ES with 5 animals per group. After 5 days lungs were harvested and analyzed by H&E staining of tissue sections. RESULTS: In an in vitro permeability assay VEGF enhanced permeation of dye through a monolayer of endothelial cells. ES significantly inhibited VEGF induced permeability (fig.1). ES alone had no effect compared to controls. On the molecular level VEGF causes phosphorylation of its receptor VEGFR-2 as seen in VEGFR-2 expressing cells (fig.2). This effect was abolished by coincubation with ES showing a direct antagonism of VEGF signalling by ES. In a SCID mouse model animals were treated with VEGF, ES or the combination of both (fig.3). Animals in the VEGF group developed general edema and lung injury resembling acute lung injury with extravasation, accumulation of inflammatory cells and hemorrhage. The animals treated with a combination of VEGF and ES had less generalized edema. The lung sections showed alterations less pronounced than in the VEGF group. ES alone had no effect. CONCLUSIONS: Our results demonstrate that ES inhibits VEGF-induced permeability by blocking VEGFR-2 activation. ES treatment partially restored VEGF-induced lung injury in vivo. The incomplete inhibition may be due to excess VEGF protein levels. Taken together, VEGF blocking with ES may serve as a useful new treatment option for conditions with increased vascular permeability like acute lung injury.


Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 696-696
Author(s):  
Anna Missiou ◽  
Natascha Köstlin ◽  
Christian Münkel ◽  
Dietmar Pfeifer ◽  
Katja Zirlik ◽  
...  

Abstract Members of the tumor necrosis factor (TNF) interleukin/toll-like receptor superfamily such as CD40L, TNFa, and IL-1b potently promote atherogenesis in mice and likely also in humans. TNF receptor associated factors (TRAFs) are cytoplasmic adaptor proteins for this group of cytokines. We recently reported over-expression of TRAFs in murine and human atheromata and demonstrated dependency of classic inflammatory functions on TRAFs in endothelial cells and macrophages. Here we test the hypothesis that TRAF-1 modulates atherogenesis in vivo. TRAF-1--/LDLR--mice fed a high cholesterol diet for 18 weeks developed significantly smaller atherosclerotic lesions compared with LDLR--controls. Intimal lesion size decreased by up to 56±6% and 33±5% in sections of the aortic arch and aortic root, respectively (n>10 per group, P<0.01 each). Plaques of TRAF-1-deficient animals contained up to 46±9% and 55±4% fewer macrophages while smooth muscle cell content increased by up to 32±6 and 36±7%, characteristics associated with non disrupted plaques in humans. Lipid content, collagen content, and lymphocyte content remained unchanged. In vitro, gene expression profiling revealed reduced expression of adhesion molecules (VCAM-1, ICAM-1), chemokines (CCL2, CXCL2), and growth factors (M-CSF) in TRAF-1-deficient endothelial cells as well as of integrins (CD29, CD11b) and chemokines/chemokine receptors (CXCL2, CCR1) in TRAF-1-deficient macrophages, verified by siRNA studies in human cells. Finally, both deficiency of TRAF-1 in endothelial cells and neutrophils/monocytes reduced adhesion of inflammatory cells to the endothelium in static and dynamic adhesion assays. We present the novel finding that TRAF 1 deficiency attenuates atherogenesis in mice, an effect most likely mediated by impaired monocyte recruitment to the vessel wall. These data identify TRAF-1 as potential treatment target for chronic inflammatory diseases such as atherosclerosis.


1988 ◽  
Vol 255 (3) ◽  
pp. H554-H562 ◽  
Author(s):  
C. J. Meininger ◽  
M. E. Schelling ◽  
H. J. Granger

The proliferation of bovine aortic or coronary venular endothelial cells (EC) in vitro was stimulated by the addition of adenosine (0.5 or 5.0 microM) to the culture medium. Cell counts of adenosine-treated aortic EC were 23–76% and coronary venular EC 19–52% greater than nontreated controls. Because adenosine is known to be released by hypoxic tissues, cell proliferation was quantitated when aortic EC were grown at 2% O2. Cell counts were 41–102% greater under hypoxic conditions than when cells were grown at standard tissue culture conditions (approximately 20% O2). When culture medium conditioned by coronary EC grown at 2% O2 was added to EC growing at standard conditions, cell counts were 24–69% greater than controls with medium conditioned by coronary EC grown at 20% O2. This suggests that hypoxia causes endothelial cells to release a factor(s) into the medium that can stimulate cell proliferation. The addition of the adenosine receptor blocker 8-phenyltheophylline (10(-5) M) prevented the stimulation of proliferation caused by hypoxia-conditioned medium, 2% O2 or 5.0 microM adenosine, suggesting that adenosine mediates its effect via an external membrane receptor. Adenosine also stimulated EC chemotaxis. Taken together, these results suggest that adenosine, released as a result of tissue hypoxia, may act as an angiogenic stimulus for the growth of new blood vessels.


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