Platelet-Rich Plasma Promotes the Expansion of Human Myoblasts and Favors the In Vitro Generation of Human Muscle Reserve Cells in a Deeper State of Quiescence.

Stem cell therapy holds significant potential for skeletal muscle repair, with in vitro-generated human muscle reserve cells (MuRCs) emerging as a source of quiescent myogenic stem cells that can be injected to enhance muscle regeneration. However, the clinical translation of such therapies is hampered by the need for fetal bovine serum (FBS) during the in vitro generation of human MuRCs. This study aimed to determine whether fresh allogeneic human platelet-rich plasma (PRP) combined or not with hyaluronic acid (PRP-HA) could effectively replace xenogeneic FBS for the ex vivo expansion and differentiation of human primary myoblasts. Cells were cultured in media supplemented with either PRP or PRP-HA and their proliferation rate, cytotoxicity and myogenic differentiation potential were compared with those cultured in media supplemented with FBS. The results showed similar proliferation rates among human myoblasts cultured in PRP, PRP-HA or FBS supplemented media, with no cytotoxic effects. Human myoblasts cultured in PRP or PRP-HA showed reduced fusion ability upon differentiation. Nevertheless, we also observed that human MuRCs generated from PRP or PRP-HA myogenic cultures, exhibited increased Pax7 expression and delayed re-entry into the cell cycle upon reactivation, indicating a deeper quiescent state of human MuRCs. These results suggest that allogeneic human PRP effectively replaces FBS for the ex vivo expansion and differentiation of human myoblasts and favors the in vitro generation of Pax7High human MuRCs, with important implications for the advancement of stem cell-based muscle repair strategies.

Autologous Platelet-Rich Plasma in Clitoral Reconstructive Surgery After Female Genital Mutilation/Cutting: A Pilot Case Study.

BACKGROUND: Postoperative healing after clitoral reconstruction (CR) for female genital mutilation/cutting can be long and painful due to prolonged clitoral re-epithelialization time (up to 3 months). Autologous platelet-rich plasma (A-PRP) might reduce postoperative clitoral epithelialization time and pain. OBJECTIVES: The authors assessed postoperative clitoral re-epithelialization time and pain after intraoperative clitoral administration of A-PRP. METHODS: Five consecutive women underwent CR (Foldès technique) followed by the administration of A-PRP Regen Lab SA (Le Mont-sur-Lausanne, Switzerland) plasma and glue, injected inside and applied above the re-exposed clitoris, respectively. We recorded surgical complications, postoperative clitoral pain (visual analogue scale), painkiller intake, time to complete re-epithelialization, and the experienced subjective changes in sexual response and perception of their own body image referred by women. RESULTS: Sexual distress/dysfunction as well as the desire to be physically and symbolically "repaired" were the reasons behind women's requests for surgery. None of the women suffered from chronic vulvar or non-vulvar pain. All women achieved complete clitoral epithelialization by day 80, 3 women between day 54 and 70, and only 1 woman was still taking 1 g of paracetamol twice a day at 2 months postoperative. She had stopped it before the 3-month control. There were no short- or long-term complications. All women described easier access and stimulation of their clitoris as well as improved sexual arousal, lubrication, and pleasure and claimed to be satisfied with their restored body image. CONCLUSIONS: A-PRP could expedite postoperative clitoral epithelialization and reduce postoperative pain after CR after female genital mutilation/cutting.

Use of Autologous Platelet Rich Plasma (A-PRP) for Postpartum Perineal Repair Failure: A Case Report.

Perineal wound dehiscence is an uncommon but important postpartum complication. In many cases, it leads to extreme pain and urinary and defecation problems. For up to several weeks, it can interfere with the mother's daily activity, affecting psychosexual health and body image. The best way to manage perineal wound breakdown (resuturing vs. spontaneous closure) after childbirth remains controversial. A-PRP is the autologous human plasma containing an increased platelet concentration, rich in growth factors, and mediators with hemostatic, anti-inflammatory, and antimicrobial properties. It accelerates the natural healing process. Even though A-PRP is widely used in orthopedics and dermatology, its use in gynecological injuries is limited. We describe here a case of a woman with postpartum perineal dehiscence treated with A-PRP with positive outcomes.

Swiss Medical Devices for Autologous Regenerative Medicine: From Innovation to Clinical Validation.

Regenerative medicine, based on the use of autologous tissues and embryonic, stem or differentiated cells, is gaining growing interest. However, their preparation, in a manner compliant with good practices and health regulations, is a technical challenge. The aim of this manuscript is to present the design of reliable CE marked medical devices for the preparation of standardized platelet-rich plasma (PRP) and other autologous biologics intended for therapeutic uses. There are numerous PRP isolation processes. Depending on the methodology used, PRP composition varies greatly in terms of platelet concentration, platelet quality, and level of contamination with red and white blood cells. This variability in PRP composition might affect the clinical outcomes. The devices presented here are based on a specific technology, patented all over the world, that allows the precise separation of blood components as a function of their density using thixotropic separator gels in closed systems. This allows the preparation, in an automated manner, of leukocyte poor PRP with a standardized composition. Production of different forms of PRP is a clinical asset to suit various therapeutic needs. Therefore, we are offering solutions to prepare PRP either in liquid or gel form, and PRP combined with hyaluronic acid. These biologics have been successfully used in many different therapeutic domains, resulting in more than 150 published clinical studies. We also developed the CuteCell technology platform for cell culture expansion for further autologous cell therapies. This technology enables the safe and rapid in vitro expansion of cells intended for therapeutic use in good manufacturing practices (GMP) and autologous conditions, using blood-derived products as culture media supplementation. We summarize in this article our 20 years' experience of research and development for the design of PRP devices and, more recently, for PRP combined with hyaluronic acid.

Amphetamine-Type Stimulant Dependence and Association with Concurrent Use of Cocaine, Alcohol, and Cannabis: A Cross-Sectional Study.

INTRODUCTION: Amphetamine-type stimulants (ATSs) are the second most commonly used class of illegal substances in Europe. Although concurrent substance use has been subject to research, little is known about associations between concurrent use of cocaine, alcohol, or cannabis and ATS dependence. We expect that the concurrent use of any of the substance, especially cannabis and cocaine, is associated with ATS dependence. METHODS: Cross-sectional data were gathered within the European ATTUNE study in 2018/2019. Participants (N = 721) were asked about their consumption patterns and social, psychological, and economic situation. Multivariate logistic regressions were carried out for associations between ATS dependence and use combinations of frequent cocaine, alcohol, or cannabis, with the reference group of no frequent concurrent use (model 1). Model 2 calculated associations for ATS dependence with lifetime methamphetamine use for respective use combinations. RESULTS: The study population was on average 28.9 years old (SD = 7.7), with the majority being male (63.5%). In model 1, the adjusted odds ratio (aOR) for frequent alcohol use was 0.70 (confidence interval [CI] 0.41-1.20). Similar results were shown for model 2 (aOR 0.82, CI 0.42-1.62). Frequent cannabis use significantly reduced the chance for ATS dependence by 50% in adjusted model 1 (aOR 0.50, CI 0.28-0.89) and by 62% in model 2 (aOR 0.38, CI 0.18-0.82). For frequent cocaine use, models 1 and 2 report an aOR at 1.37 (CI 0.58-3.25) and 2.39 (CI 0.77-7.43), although not statistically significant. Frequent users of all 3 substances had a significant 3-fold chance for ATS dependence (model 1: aOR 2.98, CI 1.16-7.63; model 2: aOR 2.95, CI 1.02-8.58). DISCUSSION: Against initial hypotheses, frequent concurrent use of alcohol or cannabis generally decreased chances for ATS dependence. An explanation could be the study population, which consists of many irregular users of ATS, who mainly consume alcohol or cannabis. Cocaine generally increased chances, although results were not significant. The frequent use of all 3 substances together with ATS in the last year was significantly associated with dependence, thus reporting important information for treatment services. Further research is needed for disentangling causal relationships underlying these associations and for pinpointing consequences for relapse prevention and retention success.

Autologous Platelet-Rich Plasma for Clitoral Reconstruction: A Case Study.

Clitoral reconstruction after female genital mutilation/cutting (FGM/C) is associated with significant post-operative pain and months-long recovery. Autologous platelet-rich plasma (A-PRP) reduces the time of healing and pain in orthopedic and burn patients and could also do so in clitoral reconstruction. In the present case, a 35-year-old Guinean woman who had undergone FGM/C Type IIb presented to our clinic for clitoral reconstruction. Her request was motivated by low sexual satisfaction and body image. We surgically reconstructed the clitoris using the Foldès method and applied plasma and glue of A-PRP. The patient was highly satisfied with the procedure. Two months post-operatively, her pain had ceased entirely and re-epithelialization was complete. We conclude that A-PRP may improve pain and healing after clitoral reconstruction. Extensive studies investigating long-term outcomes are needed.

Angiogenesis Is Differentially Modulated by Platelet-Derived Products.

Platelet-derived preparations are being used in clinic for their role in tissue repair and regenerative processes. The release of platelet-derived products such as autologous growth factors, cytokines and chemokines can trigger therapeutic angiogenesis. In this in vitro study, we evaluated and compared the ability of three platelet-derived preparations: platelet-rich-plasma (PRP), PRP-hyaluronic acid (PRP-HA) and platelet lysates (PL) at various concentrations (5-40%) to modulate human umbilical vein endothelial cells (HUVEC) biological effects on metabolism, viability, senescence, angiogenic factors secretion and angiogenic capacities in 2D (endothelial tube formation assay or EFTA) and in 3D (fibrin bead assay or FBA). HUVEC exocytosis was stimulated with PRP and PRP-HA. Cell viability was strongly increased by PRP and PRP-HA but mildly by PL. The three preparations inhibit HUVEC tube formation on Matrigel, while PRP enhanced the complexity of the network. In the fibrin bead assay (FBA), PRP and PRP-HA stimulated all steps of the angiogenic process resulting in massive sprouting of a branched microvessel network, while PL showed a weaker angiogenic response. Secretome profiling revealed modulation of 26 human angiogenic proteins upon treatment with the platelet derived preparations. These in vitro experiments suggest that PRP and PRP-HA are effective biological therapeutic tools when sustained therapeutic angiogenesis is needed.

Production of Autologous Platelet-Rich Plasma for Boosting In Vitro Human Fibroblast Expansion.

There is currently great clinical interest in the use of autologous fibroblasts for skin repair. In most cases, culture of skin cells in vitro is required. However, cell culture using xenogenic or allogenic culture media has some disadvantages (i.e., risk of infectious agent transmission or slow cell expansion). Here, an autologous culture system is developed for the expansion of human skin fibroblast cells in vitro using a patient's own platelet-rich plasma (PRP). Human dermal fibroblasts are isolated from the patient while undergoing abdominoplasty. Cultures are followed for up to 7 days using a medium supplemented with either fetal bovine serum (FBS) or PRP. Blood cell content in PRP preparations, proliferation, and fibroblast differentiation are assessed. This protocol describes the method for obtaining a standardized, non-activated preparation of PRP using a dedicated medical device. The preparation requires only a medical device (CuteCell-PRP) and centrifuge. This device is suitable under sufficient medical practice conditions and is a one-step, apyrogenic, and sterile closed system that requires a single, soft spin centrifugation of 1,500 x g for 5 min. After centrifugation, the blood components are separated, and the platelet-rich plasma is easily collected. This device allows a quick, consistent, and standardized preparation of PRP that can be used as a cell culture supplement for in vitro expansion of human cells. The PRP obtained here contains a 1.5-fold platelet concentration compared to whole blood together, with a preferential removal of red and white blood cells. It is shown that PRP presents a boosting effect in cell proliferation compared to FBS (7.7x) and that fibroblasts are activated upon PRP treatment.

Angiogenesis Analyzer for ImageJ - A comparative morphometric analysis of "Endothelial Tube Formation Assay" and "Fibrin Bead Assay".

Angiogenesis assays based on in vitro capillary-like growth of endothelial cells (EC) are widely used, either to evaluate the effect of anti- and pro-angiogenesis drugs of interest, or to test and compare the functional capacities of various types of EC and progenitor cells. Among the different methods applied to study angiogenesis, the most commonly used is the "Endothelial Tube Formation Assay" (ETFA). In suitable culture conditions, EC form two-dimensional (2D) branched structures that can lead to a meshed pseudo-capillary network. An alternative approach to ETFA is the "Fibrin Bead Assay" (FBA), based on the use of Cytodex 3 microspheres, which promote the growth of 3D capillary-like patterns from coated EC, suitable for high throughput in vitro angiogenesis studies. The analytical evaluation of these two widely used assays still remains challenging in terms of observation method and image analysis. We previously developed the "Angiogenesis Analyzer" for ImageJ (AA), a tool allowing analysis of ETFA-derived images, according to characteristics of the pseudo-capillary networks. In this work, we developed and implemented a new algorithm for AA able to recognize microspheres and to analyze the attached capillary-like structures from the FBA model. Such a method is presented for the first time in fully automated mode and using non-destructive image acquisition. We detailed these two algorithms and used the new AA version to compare both methods (i.e. ETFA and FBA) in their efficiency, accuracy and statistical relevance to model angiogenesis patterns of Human Umbilical Vein EC (HUVEC). Although the two methods do not assess the same biological step, our data suggest that they display specific and complementary information on the angiogenesis processes analysis.

Platelet Transforming Growth Factor-ß1 Induces Liver Sinusoidal Endothelial Cells to Secrete Interleukin-6.

The roles and interactions of platelets and liver sinusoidal endothelial cells in liver regeneration are unclear, and the trigger that initiates hepatocyte proliferation is unknown. We aimed to identify the key factors released by activated platelets that induce liver sinusoidal endothelial cells to produce interleukin-6 (IL-6), a cytokine implicated in the early phase of liver regeneration. We characterized the releasate of activated platelets inducing the in vitro production of IL-6 by mouse liver sinusoidal endothelial cells and observed that the stimulating factor was a thermolabile protein. Following gel filtration, a single fraction of activated platelet releasate induced a maximal IL-6 secretion by liver sinusoidal endothelial cells (90.2 ± 13.9 versus control with buffer, 9.0 ± 0.8 pg/mL, p < 0.05). Mass spectroscopy analysis of this fraction, followed by in silico processing, resulted in a reduced list of 18 candidates. Several proteins from the list were tested, and only recombinant transforming growth factor ß1 (TGF-ß1) resulted in an increased IL-6 production up to 242.7 ± 30.5 pg/mL, which was comparable to non-fractionated platelet releasate effect. Using neutralizing anti-TGF-ß1 antibody or a TGF-ß1 receptor inhibitor, IL-6 production by liver sinusoidal endothelial cells was dramatically reduced. These results support a role of platelet TGF-ß1 ß1 in the priming phase of liver regeneration.

Autologous Platelet-Rich Plasma (CuteCell PRP) Safely Boosts In Vitro Human Fibroblast Expansion.

Nowadays autologous fibroblast application for skin repair presents an important clinical interest. In most cases, in vitro skin cell culture is mandatory. However, cell expansion using xenogeneic or allogenic culture media presents some disadvantages, such as the risk of infection transmission or slow cell expansion. In this study, we investigated an autologous culture system to expand human skin fibroblast cells in vitro with the patient's own platelet-rich plasma (PRP). Human dermal fibroblasts were isolated from patients undergoing abdominoplasty, and blood was collected to prepare nonactivated PRP using the CuteCell™ PRP medical device. Cultures were followed up to 7 days using a medium supplemented with either fetal bovine serum (FBS) or PRP. Fibroblasts cultured in medium supplemented with PRP showed dose-dependently significantly higher proliferation rates (up to 7.7 times with 20% of PRP) and initiated a faster migration in the in vitro wound healing assay compared with FBS, while chromosomal stability was maintained. At high concentrations, PRP changed fibroblast morphology, inducing cytoskeleton rearrangement and an increase of alpha-smooth muscle actin and vimentin expression. Our findings show that autologous PRP is an efficient and cost-effective supplement for fibroblast culture, and should be considered as a safe alternative to xenogeneic/allogenic blood derivatives for in vitro cell expansion. Impact Statement Autologous dermal fibroblast graft is an important therapy in skin defect repair, but in vitro skin cell culture is mandatory in most cases. However, cell expansion using xenogeneic/allogenic culture media presents some disadvantages, such as the risk of infection transmission. We demonstrated that an autologous culture system with the patient's own platelet-rich plasma is an efficient, cost-effective, and safe supplement for fibroblast culture. As it respects the good manufacturing practices and regulatory agencies standards, it should be considered as a potent alternative and substitute to xenogeneic or allogenic blood derivatives for the validation of future clinical protocols using in vitro cell expansion.

NF-κB and Angiogenesis Inhibitors from the Aerial Parts of Chresta martii.

The ethyl acetate extract of the aerial parts of Chresta martii showed significant in vitro NF-κB inhibition. Bioactivity-guided isolation was undertaken using HPLC microfractionation to localize the active compounds. Different zones of the HPLC chromatogram were linked to NF-κB inhibition. In parallel to this HPLC-based activity profiling, HPLC-PDA-ESI-MS and UHPLC-TOF-HRMS were used for the early identification of some of the compounds present in the extract and to get a complete phytochemical overview. The isolation of the compounds was performed by high-speed counter-current chromatography and further semipreparative HPLC. Using this approach, 14 compounds were isolated, two of them being new sesquiterpene lactones. The structures of the isolated compounds were elucidated by spectroscopic methods including UV, ECD, NMR, and HRMS. All isolated compounds were evaluated for their inhibitory activity of NF-κB and angiogenesis, and compound 2 showed promising NF-κB inhibition activity with an IC50 of 0.7 µM. The isolated compounds 1, 2, 5, 7, and 8 caused a significant reduction in angiogenesis when evaluated by an original 3D in vitro angiogenesis assay.

A Bivalent Role of Genistein in Sprouting Angiogenesis.

The effects of genistein on angiogenesis remain poorly understood. Some studies claim an antiangiogenic effect and others claim a pro-angiogenic one. Thus, the aim of this study was to determine if genistein may exhibit bivalent angiogenic effects. To address this question, genistein angiogenic modulatory effects were examined using an in vitro 3D angiogenesis model using human umbilical vein endothelial cells. In this model, a bivalent effect of genistein was demonstrated on sprouting angiogenesis, with angiogenic stimulation at low concentrations (0.001 - 1 µM) and inhibition at higher ones (25 - 100 µM). Enhancement of the endothelial tube formation correlated with an increase in human umbilical vein endothelial cell metabolic activity and proliferation. Inhibition of angiogenesis correlated with a decreased metabolic activity, proliferation, and migration. Moreover, high concentrations of genistein influenced human umbilical vein endothelial cell morphology. Expression of genes involved in the angiogenic process in response to genistein was measured to study the mechanism of action. Secretome profiling revealed that angiogenic regulators were modulated with genistein treatment. These results suggested a bivalent effect of genistein on human umbilical vein endothelial cell growth and angiogenesis, and further investigations on the benefit of genistein for cancer chemoprevention, cancer treatment, or pro-angiogenic therapies have to be carefully considered.

* Microcomputed Tomography Technique for In Vivo Three-Dimensional Fat Tissue Volume Evaluation After Polymer Injection.

Tissue engineering technologies are new and promising techniques in fat tissue reconstruction. However, to assess their efficacy before any clinical application, in vivo experiments are mandatory. This study assesses whether microcomputed tomography (CT) scan imaging is suitable to analyze in vivo the behavior of injected engineered polymer and changes in fat tissue. The volume of mice inguinal fat pads and the resorption rate of different polymers were analyzed by CT scan for up to 3 months. Different biomaterials were used, including our innovative microspheres loaded with oleic acid. We were able to follow in vivo the polymer and the fat volume of the same animals during a long-term follow-up of 90 days. Semiautomatic three-dimensional quantification allowed to determine the fat volume enhancement after injection, as well as the resorption rate of our product compared to other biomaterials (i.e., polylactic and hyaluronic acid) until 90 days. Our results demonstrate the encouraging proof-of-principle evidence for the application of micro-CT scan technology to follow in vivo biodegradable polymers in a fat tissue engineering approach. This noninvasive technique offers the advantages of the long-term follow-up of fat tissue and synthetic materials in the same animals, which allows both a scientific evaluation of the measurements and the reduction of the number of animals used in in vivo protocols in accordance with the 3 "R" principles governing the use of animals in science.

Bruceantin inhibits multiple myeloma cancer stem cell proliferation.

Multiple myeloma (MM) continues to claim the lives of a majority of patients. MM cancer stem cells (CSCs) have been demonstrated to sustain tumor growth. Due to their ability to self-renew and to express detoxifying enzymes and efflux transporters, MM-CSCs are rendered highly resistant to conventional therapies. Therefore, managing MM-CSCs characteristics could have profound clinical implications. Bruceantin (BCT) is a natural product previously demonstrated to inhibit the growth of MM in RPMI 8226 cells-inoculated mouse xenograft models, and to cause regression in already established tumors. The objectives of the present study were to test the inhibitory effects of BCT on MM-CSCs growth derived from a human primary tumor, and to explore a mechanism of action underlying these effects. BCT exhibited potent antiproliferative activity in MM-CSCs starting at 25 nM. BCT induced cell cycle arrest, cell death and apoptosis in MM-CSCs as well as inhibited cell migration and angiogenesis in vitro. Using a qPCR screen, it was found that the gene expression of a number of Notch pathway members was altered. Pretreatment of MM-CSCs with the γ-secretase inhibitor RO4929097, a Notch pathway inhibitor, reversed BCT-induced effects on MM-CSCs proliferation. In this study, BCT was shown to be an effective agent in controlling the proliferation, viability and migration of MM-CSCs as well as angiogenesis in vitro. The effect on MM-CSCs proliferation may be mediated by the Notch pathway. These results warrant further investigation of BCT in a broader set of human-derived MM-CSCs and with in vivo models representative of MM.

Detection and Quantification of ADP-Ribosylated RhoA/B by Monoclonal Antibody.

Clostridium botulinum exoenzyme C3 is the prototype of C3-like ADP-ribosyltransferases that modify the GTPases RhoA, B, and C. C3 catalyzes the transfer of an ADP-ribose moiety from the co-substrate nicotinamide adenine dinucleotide (NAD) to asparagine-41 of Rho-GTPases. Although C3 does not possess cell-binding/-translocation domains, C3 is able to efficiently enter intact cells, including neuronal and macrophage-like cells. Conventionally, the detection of C3 uptake into cells is carried out via the gel-shift assay of modified RhoA. Since this gel-shift assay does not always provide clear, evaluable results an additional method to confirm the ADP-ribosylation of RhoA is necessary. Therefore, a new monoclonal antibody has been generated that specifically detects ADP-ribosylated RhoA/B, but not RhoC, in Western blot and immunohistochemical assay. The scFv antibody fragment was selected by phage display using the human naive antibody gene libraries HAL9/10. Subsequently, the antibody was produced as scFv-Fc and was found to be as sensitive as a commercially available RhoA antibody providing reproducible and specific results. We demonstrate that this specific antibody can be successfully applied for the analysis of ADP-ribosylated RhoA/B in C3-treated Chinese hamster ovary (CHO) and HT22 cells. Moreover, ADP-ribosylation of RhoA was detected within 10 min in C3-treated CHO wild-type cells, indicative of C3 cell entry.

Priming Dental Pulp Stem Cells With Fibroblast Growth Factor-2 Increases Angiogenesis of Implanted Tissue-Engineered Constructs Through Hepatocyte Growth Factor and Vascular Endothelial Growth Factor Secretion.

Tissue engineering strategies based on implanting cellularized biomaterials are promising therapeutic approaches for the reconstruction of large tissue defects. A major hurdle for the reliable establishment of such therapeutic approaches is the lack of rapid blood perfusion of the tissue construct to provide oxygen and nutrients. Numerous sources of mesenchymal stem cells (MSCs) displaying angiogenic potential have been characterized in the past years, including the adult dental pulp. Establishment of efficient strategies for improving angiogenesis in tissue constructs is nevertheless still an important challenge. Hypoxia was proposed as a priming treatment owing to its capacity to enhance the angiogenic potential of stem cells through vascular endothelial growth factor (VEGF) release. The present study aimed to characterize additional key factors regulating the angiogenic capacity of such MSCs, namely, dental pulp stem cells derived from deciduous teeth (SHED). We identified fibroblast growth factor-2 (FGF-2) as a potent inducer of the release of VEGF and hepatocyte growth factor (HGF) by SHED. We found that FGF-2 limited hypoxia-induced downregulation of HGF release. Using three-dimensional culture models of angiogenesis, we demonstrated that VEGF and HGF were both responsible for the high angiogenic potential of SHED through direct targeting of endothelial cells. In addition, FGF-2 treatment increased the fraction of Stro-1+/CD146+ progenitor cells. We then applied in vitro FGF-2 priming to SHED before encapsulation in hydrogels and in vivo subcutaneous implantation. Our results showed that FGF-2 priming is more efficient than hypoxia at increasing SHED-induced vascularization compared with nonprimed controls. Altogether, these data demonstrate that FGF-2 priming enhances the angiogenic potential of SHED through the secretion of both HGF and VEGF.

The interaction of heparan sulfate proteoglycans with endothelial transglutaminase-2 limits VEGF165-induced angiogenesis.

Sprouting angiogenesis is stimulated by vascular endothelial growth factor (VEGF165) that is localized in the extracellular matrix (ECM) and binds to heparan sulfate (HS)-bearing proteins known as heparan sulfate proteoglycans (HSPGs). VEGF165 presentation by HSPGs enhances VEGF receptor-2 (VEGFR2) signaling. We investigated the effect of TG2, which binds to HSPGs, on the interaction between VEGF165 and HS and angiogenesis. Mice with tg2 deficiency showed transiently enhanced retina vessel formation and increased vascularization of VEGF165-containing Matrigel implants. In addition, endothelial cells in which TG2 was knocked down exhibited enhanced VEGF165-induced sprouting and migration, which was associated with increased phosphorylation of VEGFR2 at Tyr(951) and its targets Src and Akt. TG2 knockdown did not affect the phosphorylation of VEGFR2 at Tyr(1175) or cell proliferation in response to VEGF165 and sprouting or signaling in response to VEGF121. Decreased phosphorylation of VEGFR2 at Tyr(951) was due to ECM-localized TG2, which reduced the binding of VEGF165 to endothelial ECM in a manner that required its ability to bind to HS but not its catalytic activity. Surface plasmon resonance assays demonstrated that TG2 impeded the interaction between VEGF165 and HS. These results show that TG2 controls the formation of VEGF165-HSPG complexes and suggest that this regulation could be pharmacologically targeted to modulate developmental and therapeutic angiogenesis.

Transcriptome analysis of PPARγ target genes reveals the involvement of lysyl oxidase in human placental cytotrophoblast invasion.

Human placental development is characterized by invasion of extravillous cytotrophoblasts (EVCTs) into the uterine wall during the first trimester of pregnancy. Peroxisome proliferator-activated receptor γ (PPARγ) plays a major role in placental development, and activation of PPARγ by its agonists results in inhibition of EVCT invasion in vitro. To identify PPARγ target genes, microarray analysis was performed using GeneChip technology on EVCT primary cultures obtained from first-trimester human placentas. Gene expression was compared in EVCTs treated with the PPARγ agonist rosiglitazone versus control. A total of 139 differentially regulated genes were identified, and changes in the expression of the following 8 genes were confirmed by reverse transcription-quantitative polymerase chain reaction: a disintegrin and metalloproteinase domain12 (ADAM12), connexin 43 (CX43), deleted in liver cancer 1 (DLC1), dipeptidyl peptidase 4 (DPP4), heme oxygenase 1 (HMOX-1), lysyl oxidase (LOX), plasminogen activator inhibitor 1 (PAI-1) and PPARγ. Among the upregulated genes, lysyl oxidase (LOX) was further analyzed. In the LOX family, only LOX, LOXL1 and LOXL2 mRNA expression was significantly upregulated in rosiglitazone-treated EVCTs. RNA and protein expression of the subfamily members LOX, LOXL1 and LOXL2 were analyzed by absolute RT-qPCR and western blotting, and localized by immunohistochemistry and immunofluorescence-confocal microscopy. LOX protein was immunodetected in the EVCT cytoplasm, while LOXL1 was found in the nucleus and nucleolus. No signal was detected for LOXL2 protein. Specific inhibition of LOX activity by ß-aminopropionitrile in cell invasion assays led to an increase in EVCT invasiveness. These results suggest that LOX, LOXL1 and LOXL2 are downstream PPARγ targets and that LOX activity is a negative regulator of trophoblastic cell invasion.

Evidence for cross-talk between the LH receptor and LH during implantation in mice.

The present study investigated the first interaction that occurs between the blastocyst and endometrium during implantation. Given the ethical objections to studying implantation in humans, a mouse model was used to study the dialogue between luteinising hormone (LH) and luteinising hormone receptor (LHCGR). Several studies performed on LHCGR-knockout mice have generated controversy regarding the importance of the dialogue between LH and LHCGR during implantation. There has been no demonstration of a bioactive LH-like signal produced by the murine blastocyst. The first aim of the present study was to examine and quantify, using radioimmunoassay, the generation of a bioactive LH signal by the murine blastocyst. We went on to examine and quantify endometrial Lhcgr expression to validate the mouse model. Expression of LHCGR in mouse uteri was demonstrated using immunohistochemistry and western blot analysis. To quantify the expression of Lh in the mouse blastocyst and Lhcgr in the endometrium, reverse transcription-polymerase chain reaction (RT-PCR) and real-time quantitative (q) RT-PCR were performed. The results demonstrate that Lhcgr expression in BALB/c mouse endometrial epithelium is increased at the time of implantation and indicate that LHCGR may contribute to the implantation process. In support of this hypothesis, we identified a bioactive LH signal at the time of murine blastocyst implantation.