scholarly journals Transcription factor Krüppel-like factor 2 plays a vital role in endothelial colony forming cells differentiation

2013 ◽  
Vol 99 (3) ◽  
pp. 514-524 ◽  
Author(s):  
Yimeng Song ◽  
Xiaoxia Li ◽  
Dawei Wang ◽  
Chenglai Fu ◽  
Zhenjiu Zhu ◽  
...  

Abstract Aims Endothelial colony forming cells (ECFCs) participate in post-natal vasculogenesis. We previously reported that vascular endothelial growth factor (VEGF) promotes human ECFC differentiation through AMP-activated protein kinase (AMPK) activation. However, the mechanisms underlying transcriptional regulation of ECFC differentiation still remain largely elusive. Here, we investigated the role of transcription factor Krüppel-like factor 2 (KLF2) in the regulation of ECFC function. Methods and results Human ECFCs were isolated from cord blood and cultured. Treatment with VEGF significantly increased endothelial markers in ECFCs and their capacity for migration and tube formation. The mRNA and protein levels of KLF2 were also significantly up-regulated. This up-regulation was abrogated by AMPK inhibition or by knockdown of KLF2 with siRNA. Furthermore, adenovirus-mediated overexpression of KLF2 promoted ECFC differentiation by enhancing expression of endothelial cell markers, reducing expression of progenitor cell markers, and increasing the capacity for tube formation in vitro, indicating the important role of KLF2 in ECFC-mediated angiogenesis. Histone deacetylase 5 (HDAC5) was phosphorylated by AMPK activity induced by VEGF and the AMPK agonist AICAR (5-amino-1-β-d-ribofuranosyl-imidazole-4-carboxamide). In vivo angiogenesis assay revealed that overexpression of KLF2 in bone-marrow-derived pro-angiogenic progenitor cells promoted vessel formation when the cells were implanted in C57BL/6 mice. Conclusion Up-regulation of KLF2 by AMPK activation constitutes a novel mechanism of ECFC differentiation, and may have therapeutic value in the treatment of ischaemic heart disease.

Author(s):  
Alessio Biagioni ◽  
Anna Laurenzana ◽  
Beatrice Menicacci ◽  
Silvia Peppicelli ◽  
Elena Andreucci ◽  
...  

AbstractExosomes (Exos) have been reported to promote pre-metastatic niche formation, proliferation, angiogenesis and metastasis. We have investigated the role of uPAR in melanoma cell lines-derived Exos and their pro-angiogenic effects on human microvascular endothelial cells (HMVECs) and endothelial colony-forming cells (ECFCs). Melanoma Exos were isolated from conditioned media of A375 and M6 cells by differential centrifugation and filtration. Tunable Resistive Pulse Sensing (TRPS) and Nanoparticle tracking analysis were performed to analyze dimension and concentration of Exos. The CRISPR–Cas 9 technology was exploited to obtain a robust uPAR knockout. uPAR is expressed in melanoma Exos that are internalized by HMVECs and ECFCs, enhancing VE-Cadherin, EGFR and uPAR expression in endothelial cells that undergo a complete angiogenic program, including proliferation, migration and tube formation. uPAR loss reduced the pro-angiogenic effects of melanoma Exos in vitro and in vivo by inhibition of VE-Cadherin, EGFR and uPAR expression and of ERK1,2 signaling in endothelial cells. A similar effect was obtained with a peptide that inhibits uPAR–EGFR interaction and with the EGFR inhibitor Gefitinib, which also inhibited melanoma Exos-dependent EGFR phosphorylation. This study suggests that uPAR is required for the pro-angiogenic activity of melanoma Exos. We propose the identification of uPAR-expressing Exos as a potentially useful biomarker for assessing pro-angiogenic propensity and eventually monitoring the response to treatment in metastatic melanoma patients.


Blood ◽  
2006 ◽  
Vol 109 (4) ◽  
pp. 1479-1489 ◽  
Author(s):  
Hugo Caldas ◽  
Jason R. Fangusaro ◽  
Daniel R. Boué ◽  
Michael P. Holloway ◽  
Rachel A. Altura

Abstract The identification of alternative splice variants of Survivin that possess distinct functions from those originally identified for the main Survivin isoform has greatly increased the complexity of our understanding of the role of Survivin in different cells. Previous functional studies of the Survivin splice variants have been performed almost exclusively in cancer cells. However, Survivin has increasingly been implicated in other normal physiologic and pathophysiologic processes, including angiogenesis. In this study, we dissect the involvement of Survivin ΔEx3 in angiogenesis. We show by confocal microscopy that a pool of endothelial Survivin ΔEx3 is localized to membrane ruffles. We also demonstrate that Survivin ΔEx3 is the Survivin splice variant responsible for modulating angiogenesis in vitro, in tube formation assays, and in vivo, in an in vivo angiogenesis assay. Our data indicate that Survivin ΔEx3 may regulate angiogenesis via several mechanisms including cell invasion, migration, and Rac1 activation. Our findings identify a novel pathway regulating angiogenesis through Survivin ΔEx3 and a novel mechanism for Rac1 activation during angiogenesis. In conclusion, our results provide new insights into the regulation of endothelial cell homeostasis and angiogenesis by the Survivin proteins.


2021 ◽  
Vol 9 (2) ◽  
pp. e001364
Author(s):  
Yan Zhang ◽  
Hui Yang ◽  
Jun Zhao ◽  
Ping Wan ◽  
Ye Hu ◽  
...  

BackgroundThe activation of tumor-associated macrophages (TAMs) facilitates the progression of gastric cancer (GC). Cell metabolism reprogramming has been shown to play a vital role in the polarization of TAMs. However, the role of methionine metabolism in function of TAMs remains to be explored.MethodsMonocytes/macrophages were isolated from peripheral blood, tumor tissues or normal tissues from healthy donors or patients with GC. The role of methionine metabolism in the activation of TAMs was evaluated with both in vivo analyses and in vitro experiments. Pharmacological inhibition of the methionine cycle and modulation of key metabolic genes was employed, where molecular and biological analyses were performed.ResultsTAMs have increased methionine cycle activity that are mainly attributed to elevated methionine adenosyltransferase II alpha (MAT2A) levels. MAT2A modulates the activation and maintenance of the phenotype of TAMs and mediates the upregulation of RIP1 by increasing the histone H3K4 methylation (H3K4me3) at its promoter regions.ConclusionsOur data cast light on a novel mechanism by which methionine metabolism regulates the anti-inflammatory functions of monocytes in GC. MAT2A might be a potential therapeutic target for cancer cells as well as TAMs in GC.


Cells ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1870
Author(s):  
Klaudia Skrzypek ◽  
Grażyna Adamek ◽  
Marta Kot ◽  
Bogna Badyra ◽  
Marcin Majka

Rhabdomyosarcoma (RMS), is the most frequent soft tissue tumor in children that originates from disturbances in differentiation process. Mechanisms leading to the development of RMS are still poorly understood. Therefore, by analysis of two RMS RH30 cell line subclones, one subclone PAX7 negative, while the second one PAX7 positive, and comparison with other RMS cell lines we aimed at identifying new mechanisms crucial for RMS progression. RH30 subclones were characterized by the same STR profile, but different morphology, rate of proliferation, migration activity and chemotactic abilities in vitro, as well as differences in tumor morphology and growth in vivo. Our analysis indicated a different level of expression of adhesion molecules (e.g., from VLA and ICAM families), myogenic microRNAs, such as miR-206 and transcription factors, such as MYOD, MYOG, SIX1, and ID. Silencing of PAX7 transcription factor with siRNA confirmed the crucial role of PAX7 transcription factor in proliferation, differentiation and migration of RMS cells. To conclude, our results suggest that tumor cell lines with the same STR profile can produce subclones that differ in many features and indicate crucial roles of PAX7 and ID proteins in the development of RMS.


2015 ◽  
Vol 35 (3) ◽  
pp. 875-884 ◽  
Author(s):  
Hongyuan Song ◽  
Dongyan Pan ◽  
Weifeng Sun ◽  
Cao Gu ◽  
Yuelu Zhang ◽  
...  

Background/Aims: Annexin II receptor (AXIIR) is able to mediate Annexin II signal and induce apoptosis, but its role in angiogenesis remains unclear. This study tries to investigate the role of AXIIR in angiogenesis and the plausible molecular mechanism. Methods/Results: RNA interference technology was used to silence AXIIR, and the subsequent effects in vitro and in vivo were evaluated thereafter. Our data indicated that human umbilical vein endothelial cells (HUVECs) expressed AXIIR and knockdown of AXIIR significantly inhibited HUVECs proliferation, adhesion, migration, and tube formation in vitro and suppressed angiogenesis in vivo. Furthermore, AXIIR siRNA induced cell arrest in the S/G2 phase while had no effect on cell apoptosis. We found that these subsequent effects might be via suppressing the expression of matrix metalloproteinase 2and matrix metalloproteinase 9. Conclusion: AXIIR participates in angiogenesis, and may be a potential therapeutic target for angiogenesis related diseases.


Author(s):  
Jelena Damm ◽  
Joachim Roth ◽  
Rüdiger Gerstberger ◽  
Christoph Rummel

AbstractBackground:Studies with NF-IL6-deficient mice indicate that this transcription factor plays a dual role during systemic inflammation with pro- and anti-inflammatory capacities. Here, we aimed to characterize the role of NF-IL6 specifically within the brain.Methods:In this study, we tested the capacity of short interfering (si) RNA to silence the inflammatory transcription factor nuclear factor-interleukin 6 (NF-IL6) in brain cells underResults:In cells of a mixed neuronal and glial primary culture from the ratConclusions:This approach was, thus, not suitable to characterize the role NF-IL6 in the brain


2021 ◽  
Vol 8 ◽  
Author(s):  
Yilu Zhou ◽  
Weimin Tao ◽  
Fuyi Shen ◽  
Weijia Du ◽  
Zhendong Xu ◽  
...  

Neutrophils play a vital role in the formation of arterial, venous and cancer-related thrombosis. Recent studies have shown that in a process known as NETosis, neutrophils release proteins and enzymes complexed to DNA fibers, collectively called neutrophil extracellular traps (NETs). Although NETs were originally described as a way for the host to capture and kill bacteria, current knowledge indicates that NETs also play an important role in thrombosis. According to recent studies, the destruction of vascular microenvironmental homeostasis and excessive NET formation lead to pathological thrombosis. In vitro experiments have found that NETs provide skeletal support for platelets, red blood cells and procoagulant molecules to promote thrombosis. The protein components contained in NETs activate the endogenous coagulation pathway to promote thrombosis. Therefore, NETs play an important role in the formation of arterial thrombosis, venous thrombosis and cancer-related thrombosis. This review will systematically summarize and explain the study of NETs in thrombosis in animal models and in vivo experiments to provide new targets for thrombosis prevention and treatment.


2002 ◽  
Vol 159 (5) ◽  
pp. 867-880 ◽  
Author(s):  
Lisette Hari ◽  
Véronique Brault ◽  
Maurice Kléber ◽  
Hye-Youn Lee ◽  
Fabian Ille ◽  
...  

β-Catenin plays a pivotal role in cadherin-mediated cell adhesion. Moreover, it is a downstream signaling component of Wnt that controls multiple developmental processes such as cell proliferation, apoptosis, and fate decisions. To study the role of β-catenin in neural crest development, we used the Cre/loxP system to ablate β-catenin specifically in neural crest stem cells. Although several neural crest–derived structures develop normally, mutant animals lack melanocytes and dorsal root ganglia (DRG). In vivo and in vitro analyses revealed that mutant neural crest cells emigrate but fail to generate an early wave of sensory neurogenesis that is normally marked by the transcription factor neurogenin (ngn) 2. This indicates a role of β-catenin in premigratory or early migratory neural crest and points to heterogeneity of neural crest cells at the earliest stages of crest development. In addition, migratory neural crest cells lateral to the neural tube do not aggregate to form DRG and are unable to produce a later wave of sensory neurogenesis usually marked by the transcription factor ngn1. We propose that the requirement of β-catenin for the specification of melanocytes and sensory neuronal lineages reflects roles of β-catenin both in Wnt signaling and in mediating cell–cell interactions.


Blood ◽  
2012 ◽  
Vol 119 (5) ◽  
pp. 1302-1313 ◽  
Author(s):  
Cheng-Hsiang Kuo ◽  
Po-Ku Chen ◽  
Bi-Ing Chang ◽  
Meng-Chen Sung ◽  
Chung-Sheng Shi ◽  
...  

AbstractLewis Y Ag (LeY) is a cell-surface tetrasaccharide that participates in angiogenesis. Recently, we demonstrated that LeY is a specific ligand of the recombinant lectin-like domain of thrombomodulin (TM). However, the biologic function of interaction between LeY and TM in endothelial cells has never been investigated. Therefore, the role of LeY in tube formation and the role of the recombinant lectin-like domain of TM—TM domain 1 (rTMD1)—in antiangiogenesis were investigated. The recombinant TM ectodomain exhibited lower angiogenic activity than did the recombinant TM domains 2 and 3. rTMD1 interacted with soluble LeY and membrane-bound LeY and inhibited soluble LeY-mediated chemotaxis of endothelial cells. LeY was highly expressed on membrane ruffles and protrusions during tube formation on Matrigel. Blockade of LeY with rTMD1 or Ab against LeY inhibited endothelial tube formation in vitro. Epidermal growth factor (EGF) receptor in HUVECs was LeY modified. rTMD1 inhibited EGF receptor signaling, chemotaxis, and tube formation in vitro, and EGF-mediated angiogenesis and tumor angiogenesis in vivo. We concluded that LeY is involved in vascular endothelial tube formation and rTMD1 inhibits angiogenesis via interaction with LeY. Administration of rTMD1 or recombinant adeno-associated virus vector carrying TMD1 could be a promising antiangiogenesis strategy.


Blood ◽  
2000 ◽  
Vol 96 (1) ◽  
pp. 176-181 ◽  
Author(s):  
Daisy W. J. van der Schaft ◽  
Elly A. H. Toebes ◽  
Judith R. Haseman ◽  
Kevin H. Mayo ◽  
Arjan W. Griffioen

Abstract Bactericidal/permeability-increasing protein (BPI) has been known for some time to function in killing bacteria and in neutralizing the effects of bacterial endotoxin lipopolysaccharide. In the present study, BPI is found to be a novel endogenous inhibitor of angiogenesis. Within the sub-μM range, BPI shows a concentration-dependent inhibition of endothelial cell (EC) proliferation that is mediated by cell detachment and subsequent induction of apoptosis. As measured by flow cytometric analysis of the percentage of subdiploid cells, apoptosis induction was half-maximal at about 250 nmol/L BPI. Apoptosis was confirmed by quantification of cells with nuclear fragmentation. Apoptosis was found to be EC specific. In an in vitro collagen gel-based angiogenesis assay, BPI at 1.8 μmol/L inhibited tube formation by 81% after only 24 hours. Evidence for in vivo inhibition of angiogenesis was obtained, using the chorioallantoic membrane assay in which BPI was seen to be significantly effective at concentrations as low as 180 nmol/L. This newly discovered function of BPI might provide a possible therapeutic modality for the treatment of various pathologic disorders that depend on angiogenesis.


Sign in / Sign up

Export Citation Format

Share Document