A Novel Physiological Glycosaminoglycan-Deficient Splice Variant of Neuropilin-1 Is Anti-Tumorigenic In Vitro and In Vivo
; ; Brohée, Laura et al
in PLoS ONE (2016)
Neuropilin-1 (NRP1) is a transmembrane protein acting as a co-receptor for several growth factors and interacting with other proteins such as integrins and plexins/semaphorins. It is involved in axonal ... [more ▼]
Neuropilin-1 (NRP1) is a transmembrane protein acting as a co-receptor for several growth factors and interacting with other proteins such as integrins and plexins/semaphorins. It is involved in axonal development, angiogenesis and cancer progression. Its primary mRNA is subjected to alternative splicing mechanisms generating different isoforms, some of which lack the transmembrane domain and display antagonist properties to NRP1 full size (FS). NRP1 is further post-translationally modified by the addition of glycosaminoglycans (GAG) side chains through an O-glycosylation site at serine612. Here, we characterized a novel splice variant which has never been investigated, NRP1-Δ7, differing from the NRP1-FS by a deletion of 7 amino acids occurring two residues downstream of the O-glycosylation site. This short sequence contains two aspartic residues critical for efficient glycosylation. As expected, the high molecular weight products appearing as a smear in SDS-PAGE and reflecting the presence of GAG in NRP1-FS were undetectable in the NRP1-Δ7 protein. NRP1-Δ7 mRNA was found expressed at an appreciable level, between 10 and 30% of the total NRP1, by various cells lines and tissues from human and murine origin. To investigate the biological properties of this isoform, we generated prostatic (PC3) and breast (MDA-MB-231) cancer cells able to express recombinant NRP1-FS or NRP1-Δ7 in a doxycycline-inducible manner. Cells with increased expression of NRP1-Δ7 were characterized in vitro by a significant reduction of proliferation, migration and anchorage-independent growth, while NRP1-FS had the expected opposite “pro-tumoral” effects. Upon VEGF-A165 treatment, a lower internalization rate was observed for NRP1-Δ7 than for NRP1-FS. Finally, we showed that NRP1-Δ7 inhibited growth of prostatic tumors and their vascularization in vivo. This report identifies NRP1-Δ7 as a splice variant displaying anti-tumorigenic properties in vitro and in vivo, emphasizing the need to consider this isoform in future studies. [less ▲]Detailed reference viewed: 16 (4 ULg)
ADAMTS3 activity is mandatory for embryonic lymphangiogenesis and regulates placental angiogenesis.
Dupont, Laura ; ; et al
Conference (2016, June)Detailed reference viewed: 19 (4 ULg)
Chitosan-based nanofibers mats for tissue engineering
Aqil, Abdelhafid ; Croisier, Florence ; Colige, Alain et al
Conference (2016, May)
Polymer hydrogels resemble the natural living tissue due to their high water content and soft consistency. They find many applications in the design and production of contact and intraocular lenses ... [more ▼]
Polymer hydrogels resemble the natural living tissue due to their high water content and soft consistency. They find many applications in the design and production of contact and intraocular lenses, biosensors membranes, matrices for repairing and regenerating a wide diversity of tissues and organs. Polysaccharides such as chitosan and hyaluronic acid based hydrogels have shown a great potential for biomedical and pharmaceutical applications, on account of their remarkable compatibility with physiological medium. Besides, it is degraded in a physiological environment into non-toxic products, which make them outstanding candidates for short- to medium-term applications, especially for tissue engineering. In this respect, the preparation of nanometric fibers mats based on this polysaccharide are highly interesting as such structure mimics the one of skin extracellular matrix. Such nanofibrous materials can be prepared by electrospinning (Figure 1). This technique uses a high voltage to create an electrically charged jet of polymer solution to obtain polymer fibers ranging from nanometers to a few microns in diameter. We thus have investigated strategies allowing to generate chitosan based nanofiber mats exhibiting a mechanical resistance strong enough to be easily handled while keeping the peculiar features of chitosan hydrogels favoring the interaction with cells and soft tissues to provide efficient tissue reconstruction. In a first strategy, polysaccharide-based nanofibers with a multilayered structure were prepared by combining electrospinning (ESP) and layer-by-layer (LBL) deposition techniques. Elastic nanofibers bearing charges at their surface were firstly prepared by electrospinning poly(ε-caprolactone) (PCL) with a polyelectrolyte precursor. After activation by adjusting the pH, the layer-by-layer deposition of chitosan and hyaluronic acid, can be used to coat the electrospun fibers. A multilayered structure is then achieved by alternating the deposition of the positively charged chitosan with the deposition of a negatively charged polyelectrolyte. These novel polysaccharide-coated PCL fiber mats remarkably combine the mechanical resistance typical of the core material (PCL) – particularly in the hydrated state –, with the surface properties of chitosan. Besides, crosslinked nanofibrous mats of chitosan and polyethylene oxide blends, were successfully prepared via electrospinning technique followed by heat mediated chemical crosslinking. This chemical cross-linking allows adjusting the mechanical resistance of the mats while preserving their biocompatibility. In both cases, the control of the nanofiber structure offered by the electrospinning technology, makes the developed processes very promising to precisely design biomaterials for tissue engineering. Preliminary cell culture tests corroborate the potential use of such systems in wound healing applications. [less ▲]Detailed reference viewed: 533 (12 ULg)
Determination of the substrate repertoire of ADAMTS2, 3 and 14 significantly broadens their functions and identifies extracellular matrix organization and TGF-beta signaling as primary targets.
Bekhouche, Mourad ; Leduc, Cédric ; et al
in FASEB Journal (2016)Detailed reference viewed: 43 (13 ULg)
Expanding the clinical and mutational spectrum of the Ehlers-Danlos syndrome Dermatosparaxis.
; Colige, Alain ; et al
in Genetics in Medicine : Official Journal of the American College of Medical Genetics (2016)Detailed reference viewed: 129 (4 ULg)
Lipin-1 regulates cancer cell phenotype and is a potential target to potentiate rapamycin treatment
Brohée, Laura ; ; Willems, Jérôme et al
in Oncotarget (2015), 6(13), 11264-11280
Lipogenesis inhibition was reported to induce apoptosis and repress proliferation of cancer cells while barely affecting normal cells. Lipins exhibit dual function as enzymes catalyzing the ... [more ▼]
Lipogenesis inhibition was reported to induce apoptosis and repress proliferation of cancer cells while barely affecting normal cells. Lipins exhibit dual function as enzymes catalyzing the dephosphorylation of phosphatidic acid to diacylglycerol and as co-transcriptional regulators. Thus, they are able to regulate lipid homeostasis at several nodal points. Here, we show that lipin-1 is up-regulated in several cancer cell lines and overexpressed in 50 % of high grade prostate cancers. The proliferation of prostate and breast cancer cells, but not of non-tumorigenic cells, was repressed upon lipin-1 knock-down. Lipin-1 depletion also decreased cancer cell migration through RhoA activation. Lipin-1 silencing did not significantly affect global lipid synthesis but enhanced the cellular concentration of phosphatidic acid. In parallel, autophagy was induced while AKT and ribosomal protein S6 phosphorylation were repressed. We also observed a compensatory regulation between lipin-1 and lipin-2 and demonstrated that their co-silencing aggravates the phenotype induced by lipin-1 silencing alone. Most interestingly, lipin-1 depletion or lipins inhibition with propranolol sensitized cancer cells to rapamycin. These data indicate that lipin-1 controls main cellular processes involved in cancer progression and that its targeting, alone or in combination with other treatments, could open new avenues in anticancer therapy. [less ▲]Detailed reference viewed: 45 (20 ULg)
Study of a new splice variant of Neuropilin-1: antagonistic functions in the regulation of cancer progression?
Hendricks, Céline ; ; et al
Poster (2015, April 22)
Neuropilin-1 (NRP1) is a transmembrane glycoprotein and a co-receptor for several growth factors, for example some variants of the Vascular Endothelial Growth Factor A (VEGF-A). It largely contributes to ... [more ▼]
Neuropilin-1 (NRP1) is a transmembrane glycoprotein and a co-receptor for several growth factors, for example some variants of the Vascular Endothelial Growth Factor A (VEGF-A). It largely contributes to the regulation of angiogenesis but also to cancer formation. NRP1 can be considered as a proteoglycan as glycosaminoglycans side chains can be added on serine 612. Currently, six splice variants of NRP1 have been described. An additional form was recently identified in our laboratory. Depending upon the cell types, it represents 20-30% of the total amount of NRP1. As compared to the full size NRP1 (NRP1-FS), 7 amino acids are deleted. As the missing sequence is located 2 amino acids downstream of the Ser612 required for glycosaminoglycans addition, this process could be somehow affected and the function of the protein could be modified. The glycosylation of NRP1-FS and -Δ7 was analyzed in different cells overexpressing each isoform. Western blotting analyses suggested that NRP1-Δ7 was less glycosylated than NRP1-FS. Prostate cancer cells (PC3) were engineered to express NRP1-FS or –Δ7 only in the presence of doxycycline. The migration of these cells was analyzed by scratch assay, with or without doxycycline in the medium. As compared to controls and to NRP1-FS-expressing cells, production of NRP1-Δ7 was linked to a reduction of cell migration. A DNA dosage showed that NRP1-FS enhanced cell proliferation, while NRP1-Δ7 reduced it. Tumor growth was assessed in vitro by a culture in soft agar. As compared to control conditions, expression of NRP1-FS by doxycycline increased colonies formation. By contrast, NRP1-Δ7 inhibited colonies number, suggesting an inhibition of tumorigenesis by this variant. As PC3 cells express basal level of endogenous NRP1, this suggests some competitive inhibition of NRP1 functions by NRP1-Δ7. Finally, the function of each variant was investigated in vivo in a model of injection in the flanks of nude mice of PC3 cells conditionally expressing NRP1-FS or -Δ7. As compared to the control, NRP1-FS increased tumor size and weight. By sharp contrast, the expression of NRP1-Δ7 was associated with a reduction of tumorigenicity. Cells with forced expression of NRP1-Δ7 also developed fewer blood vessels as compared to the control. These results suggest that NRP1-Δ7 have an antagonistic action on cancer formation and angiogenesis. [less ▲]Detailed reference viewed: 74 (4 ULg)
Gene Expression Study in Positron Emission Tomography–Positive Abdominal Aortic Aneurysms Identifies CCL18 as a Potential Biomarker for Rupture Risk
Courtois, Audrey ; Nusgens-Richelle, Betty ; HUSTINX, Roland et al
in Molecular Medicine (2015)
Rupture of abdominal aortic aneurysm (AAA) is a cause of significant mortality and morbidity in ageing populations. Uptake of 18-fluorodeoxyglucose (FDG) detected by positron emission tomography (PET) is ... [more ▼]
Rupture of abdominal aortic aneurysm (AAA) is a cause of significant mortality and morbidity in ageing populations. Uptake of 18-fluorodeoxyglucose (FDG) detected by positron emission tomography (PET) is observed in the wall of 12% of AAA (A+), most of them being symptomatic. We previously showed that the metabolically active areas displayed adventitial inflammation, medial degeneration and molecular alterations prefacing wall rupture. The aim of this study was to identify new factors predictive of rupture.Transcriptomic analyses were performed in the media and adventitia layers from three types of samples: AAA without (A0) and with FDG uptake (A+), both at the positive spot (A+Pos) and at a paired distant negative site (A+Neg) of the same aneurysm. Follow-up studies included RT-PCR, immunohistochemical staining and ELISA. A large number of genes, including matrix metalloproteinases, collagens and cytokines as well as genes involved in osteochondral development, were differentially expressed in the A+Pos as compared to A+Neg. Moreover, a series of genes, notably CCL18, was differentially expressed both in the A+Neg and A+Pos as compared to the A0. A significant increase of CCL18 was also found at the protein level in the aortic wall and in peripheral blood of A+ patients as compared to A0.In conclusion, new factors, including CCL18, involved in the progression of AAA and, potentially, in their rupture were identified by a genome-wide analysis of PET-positive and negative human aortic tissue samples. Further work is needed to study their role in AAA destabilization and weakening. [less ▲]Detailed reference viewed: 59 (15 ULg)
Role of the splicing factor SRSF4 in cisplatin-induced modifications of pre-mRNA splicing and apoptosis.
Gabriel, Maude ; Delforge, Yves ; Deward, Adeline et al
in BMC Cancer (2015), 15Detailed reference viewed: 49 (8 ULg)
The procollagen N-proteinases ADAMTS2, 3 and 14 in pathophysiology.
Bekhouche, Mourad ; Colige, Alain
in Matrix Biology (2015), 44-46Detailed reference viewed: 16 (1 ULg)
New biomarkers for primary mitral regurgitation.
Deroyer, Céline ; ; Moonen, Marie et al
in Clinical proteomics (2015), 12
BACKGROUND: Mitral regurgitation is a frequent valvular heart disease affecting around 2.5 % of the population with prevalence directly related to aging. Degeneration of mitral valve is broadly considered ... [more ▼]
BACKGROUND: Mitral regurgitation is a frequent valvular heart disease affecting around 2.5 % of the population with prevalence directly related to aging. Degeneration of mitral valve is broadly considered as a passive ongoing pathophysiological process and little is known about its physiological deregulation. The purpose of this study was to highlight new biomarkers of mitral regurgitation in order to decipher the underlying pathological mechanism as well as to allow the diagnosis and the monitoring of the disease. RESULTS: Modulation of various blood proteins expression was examined in patients suffering from different grades of mitral regurgitation (mild, moderate and severe) compared to healthy controls. To this end, several routine clinical assays and the multi analyte profile technology targeting 184 proteins were used. High-density lipoprotein, apolipoprotein-A1, haptoglobin and haptoglobin-alpha2 chain levels significantly decreased proportionally to the degree of mitral regurgitation when compared to controls. High-density lipoprotein and apolipoprotein-A1 levels were associated with effective regurgitant orifice area and regurgitant volume. Apolipoprotein-A1 was an independent predictor of severe mitral regurgitation. Moreover, with ordinal logistic regression, apolipoprotein-A1 remained the only independent factor associated with mitral regurgitation. In addition, myxomatous mitral valves were studied by immunocytochemistry. We observed an increase of LC3, the marker of autophagy, in myxomatous mitral valves compared with healthy mitral valves. CONCLUSION: These potential biomarkers of mitral regurgitation highlighted different cellular processes that could be modified in myxomatous degenerescence: reverse cholesterol transport, antioxidant properties and autophagy. [less ▲]Detailed reference viewed: 85 (17 ULg)
ADAMTS3 activity is mandatory for embryonic lymphangiogenesis and regulates placental angiogenesis.
; ; Bekhouche, Mourad et al
in Angiogenesis (2015)
The only documented activity of a subclass of ADAMTS proteases comprising ADAMTS2, 3 and 14 is the cleavage of the aminopropeptide of fibrillar procollagens. A limited number of in vitro studies suggested ... [more ▼]
The only documented activity of a subclass of ADAMTS proteases comprising ADAMTS2, 3 and 14 is the cleavage of the aminopropeptide of fibrillar procollagens. A limited number of in vitro studies suggested that ADAMTS3 is mainly responsible for procollagen II processing in cartilage. Here, we created an ADAMTS3 knockout mouse (Adamts3-/-) model to determine in vivo the actual functions of ADAMTS3. Heterozygous Adamts3+/- mice were viable and fertile, but their intercrosses demonstrated lethality of Adamts3-/- embryos after 15 days of gestation. Procollagens I, II and III processing was unaffected in these embryos. However, a massive lymphedema caused by the lack of lymphatics development, an abnormal blood vessel structure in the placenta and a progressive liver destruction were observed. These phenotypes are most probably linked to dysregulation of the VEGF-C pathways. This study is the first demonstration that an aminoprocollagen peptidase is crucial for developmental processes independently of its primary role in collagen biology and has physiological functions potentially involved in several human diseases related to angiogenesis and lymphangiogenesis. [less ▲]Detailed reference viewed: 44 (22 ULg)
Skin physiology in microgravity: a 3-month stay aboard ISS induces dermal atrophy and affects cutaneous muscle and hair follicles cylcing in mice.
; Nusgens-Richelle, Betty ; et al
in NPJ Microgravity (2015)Detailed reference viewed: 18 (1 ULg)
Preparation and characterizations of EGDE crosslinked chitosan electrospun membranes
Aqil, Abdelhafid ; ; Colige, Alain et al
in Clinical Hemorheology and Microcirculation (2015), 60(1), 39-50
Composite Crosslinked nanofibrous membranes of chitosan, ethylene glycol diglycidyl ether (EGDE) and polyethy- 10 lene oxide was successfully prepared with bead free morphology via electrospinning ... [more ▼]
Composite Crosslinked nanofibrous membranes of chitosan, ethylene glycol diglycidyl ether (EGDE) and polyethy- 10 lene oxide was successfully prepared with bead free morphology via electrospinning technique followed by heat mediated 11 chemical crosslinking. Architectural stability of nanofiber mat in aqueous medium was achieved by chemical crosslinking of 12 only 1% EGDE, and tensile strength tests revealed that increasing EGDE content has considerably enhance the elastic modu- 13 lus of nanofibers. The structure, morphology and mechanical properties of nanofibers were characterized by Attenuated Total 14 Reflection-Fourier Transform Infrared spectroscopy (ATR–FTIR), scanning electron microscopy (SEM) and Instron machine, 15 respectively. Skin fibroblasts and endothelial cells showedgood attachment, proliferation and viability on crosslinked electrospun 16 membranes. The results indicate a good biocompatibility and non-toxic nature of the resulted membrane. [less ▲]Detailed reference viewed: 71 (19 ULg)
Circulating miRNA signature of PET-positive abdominal aortic aneurysms: new potential predictors of rupture
Courtois, Audrey ; Nusgens-Richelle, Betty ; HUSTINX, Roland et al
in Atherosclerosis, Thrombosis and Vascular Biology (2015)Detailed reference viewed: 36 (12 ULg)
Plasma riche en plaquettes et lésions tendineuses
KAUX, Jean-François ; Drion, Pierre ; Croisier, Jean-Louis et al
in Revue Médicale de Liège (2014), 69(Synthèse 2014), 72-77
Platelets contain growth factors released during their degranulation following activation. These growth factors promote tissue remodeling, wound healing and angiogenesis. Currently, the clinical effect of ... [more ▼]
Platelets contain growth factors released during their degranulation following activation. These growth factors promote tissue remodeling, wound healing and angiogenesis. Currently, the clinical effect of Platelet-Rich Plasma (PRP) is still discussed or even controversial. Our researches have evaluated the effectiveness of PRP on the healing of animal tendons and human suffering from chronic jumper's knee. [less ▲]Detailed reference viewed: 151 (27 ULg)
Rac1 GTPase silencing counteracts microgravity-induced effects on osteoblastic cells.
; ; et al
in FASEB Journal (2014), 28(9), 4077-4087
Bone cells exposed to real microgravity display alterations of their cytoskeleton and focal adhesions, two major mechanosensitive structures. These structures are controlled by small GTPases of the Ras ... [more ▼]
Bone cells exposed to real microgravity display alterations of their cytoskeleton and focal adhesions, two major mechanosensitive structures. These structures are controlled by small GTPases of the Ras homology (Rho) family. We investigated the effects of RhoA, Rac1, and Cdc42 modulation of osteoblastic cells under microgravity conditions. Human MG-63 osteoblast-like cells silenced for RhoGTPases were cultured in the automated Biobox bioreactor (European Space Agency) aboard the Foton M3 satellite and compared to replicate ground-based controls. The cells were fixed after 69 h of microgravity exposure for postflight analysis of focal contacts, F-actin polymerization, vascular endothelial growth factor (VEGF) expression, and matrix targeting. We found that RhoA silencing did not affect sensitivity to microgravity but that Rac1 and, to a lesser extent, Cdc42 abrogation was particularly efficient in counteracting the spaceflight-related reduction of the number of focal contacts [-50% in silenced, scrambled (SiScr) controls vs. -15% for SiRac1], the number of F-actin fibers (-60% in SiScr controls vs. -10% for SiRac1), and the depletion of matrix-bound VEGF (-40% in SiScr controls vs. -8% for SiRac1). Collectively, these data point out the role of the VEGF/Rho GTPase axis in mechanosensing and validate Rac1-mediated signaling pathways as potential targets for counteracting microgravity effects [less ▲]Detailed reference viewed: 30 (9 ULg)
Ovarian tissue recovery in SCID and NOD-SCID mice after VEGF111 or VEGF165 graft treatment
Fransolet, Maïté ; HENRY, Laurie ; Blacher, Silvia et al
Poster (2014, May 19)Detailed reference viewed: 10 (0 ULg)
Impact of mice strains in ovarian tissue recovery after VEGF111 or VEGF165 graft treatment
Fransolet, Maïté ; HENRY, Laurie ; Blacher, Silvia et al
Poster (2014, May 15)Detailed reference viewed: 14 (1 ULg)