[show abstract][hide abstract] ABSTRACT: Expression of the urokinase plasminogen activator (uPA) and urokinase plasminogen activator receptor (uPAR) has recently been shown to be directly regulated by the Wnt/β-catenin signaling pathway in colon cancer cells, through β-catenin binding to T-cell factor binding element motifs present in their gene promoters. In our study, we present evidence that inhibition of β-catenin causes upregulation of uPA/uPAR gene expression enhancing invasive potential. Using MCF-7, MDA-MB-231 (breast cancer cells) and SW480 (colon cancer cells), we found that siRNA-mediated silencing of β-catenin increased uPA, uPAR and plasminogen activator inhibitor-1 (PAI-1) expression at the mRNA and protein levels. This increase was responsible for the observed enhanced invasive capacity of MDA-MB-231 and SW480 cancer cells. In addition, β-catenin stabilization and accumulation by lithium chloride treatment, a well-known inhibitor of glycogen synthase kinase-3β (GSK-3β), or by β-catenin/T-cell factor-4 expression vectors transfection led to a decrease in uPA, uPAR and PAI-1 mRNA expression in the studied cancer models. Treatment of β-catenin siRNA-transfected cells with a specific inhibitor of nuclear factor-kappaB (NF-κB), SN50, significantly reduced enhancement of uPA, uPAR and PAI-1 expression and cancer cell invasion, observed in β-catenin siRNA-transfected cells. Furthermore, β-catenin siRNA-treated cells exhibited NF-κB nuclear accumulation. These data suggest that β-catenin regulates the uPA/uPAR system in cooperation with NF-κB transcription factor, which constitutes a novel mechanism of regulation.
International Journal of Cancer 03/2011; 128(6):1280-92. · 6.20 Impact Factor
[show abstract][hide abstract] ABSTRACT: Extracellular matrix metalloproteinase inducer (EMMPRIN/CD147) is thought to promote tumor angiogenesis mostly through its protease-inducing function and more recently by its ability to increase tumor cell expression of vascular endothelial growth factor (VEGF). In this study, we present evidence that EMMPRIN can promote angiogenesis by a direct effect on endothelial cells through a paracrine regulation of the VEGF/VEGF-receptor (VEGFR) system. Using human microvascular endothelial cell line-1 endothelial cells, we show that EMMPRIN selectively increased the soluble VEGF isoforms (121 and 165), but not the matrix-bound VEGF 189 form. In addition, EMMPRIN up-regulated the expression of VEGFR-2 without an effect on VEGFR-1. This increase in VEGFR-2 was responsible for the observed EMMPRIN stimulation of the migratory and tube formation capacity of endothelial cells. EMMPRIN's effects, which were matrix metalloproteinase and urokinase-type plasminogen activator independent, were mediated primarily through hypoxia-inducible factor-2alpha expression, also up-regulated by EMMPRIN. VEGFR-2 increase was also observed in vivo in a mouse model of xenograph tumors overexpressing EMMPRIN. These results suggest that in addition to increasing protease production, EMMPRIN may contribute to the formation of a reactive stroma also through the up-regulation of hypoxia-inducible factor-2alpha, VEGFR-2, and the soluble forms of VEGF in endothelial cells, thus directly regulating the angiogenic process.
[show abstract][hide abstract] ABSTRACT: Tumor angiogenesis is a dynamic process that plays a major role in cancer progression. Vascular endothelial growth factor (VEGF) and its receptors play a pivotal role in angiogenesis. The expression of VEGF and its receptors VEGFR-1 and VEGFR-2 in renal cell carcinoma (RCC) was investigated in the perspective of anti-VEGF treatments.
Total VEGF protein levels were quantified by enzyme-linked immunosorbent assay (ELISA) in tumor tissue samples from surgical specimens of 65 patients with clear cell RCC. At the cellular level the VEGF isoforms VEGFR-1 and VEGFR-2 mRNA were quantified by real-time quantitative reverse-transcriptase polymerase chain reaction (RT-PCR) in laser-microdissected tumoral epithelial as stromal cells and in corresponding normal tissue compartments. Colocalization of VEGF and VEGFR-1 proteins was studied by triple immunofluorescent labeling.
Protein VEGF in cytosolic extracts was significantly higher in tumoral than in nontumoral tissue (P< .0001). Event-free survival was significantly longer for patients with cytosolic VEGF lower than the cutoff (75th percentile of VEGF protein levels, P= .02). In laser-microdissected epithelial cells, VEGF(121) and VEGFR-1 mRNA expressions were higher in RCC than in corresponding nontumoral kidney (P= .007 and P= .002, respectively); they were also higher in stromal cells of RCC compared with nontumoral kidney (P= .02 and P= .003, respectively). There was no differential VEGFR-2 expression in epithelial or in stromal cells of tumoral or nontumoral kidney. By immunofluorescent labeling VEGF and VEGFR-1 colocalized on RCC tumor epithelial and stromal cells.
Combined laser microdissection and quantitative RT-PCR, as triple immunofluorescent labeling, underlined the preferential expression of the most soluble VEGF isoform, VEGF(121), and its receptor VEGFR-1, but not VEGFR-2, in epithelial and stromal cells of RCC.
Cancer 01/2008; 112(2):433-42. · 5.20 Impact Factor
[show abstract][hide abstract] ABSTRACT: Our aim was to obtain a viable and easily available dermal substitute (DS) for the definitive coverage of full-thickness burns. A DS composed of a collagen-glycosaminoglycan-chitosan dermal matrix (DM) colonized with foreskin fibroblasts (FF) is described. FF-colonized DS were compared to the DM seeded with adult dermal fibroblasts (DF). FF-colonized DS expressed more fibrillin and tropoelastin than that with DF. Reconstructed skin obtained with both FF- and DF-colonized DS similarly expressed laminin-5 and collagen VII at the dermal-epidermal junction. Both FF- and DF-colonized DS produced cutaneous wound healing mediators in a dose-dependent manner in the presence of platelet lysate. After freeze-thawing, the FF-colonized DS were recovered in culture and retained their ability to produce vascular endothelial growth factor. Grafting of DS into nude rats achieved a complete healing of a dermal-epidermal lesion with a good epidermalization.
Biochemical and Biophysical Research Communications 12/2007; 363(3):472-8. · 2.41 Impact Factor
[show abstract][hide abstract] ABSTRACT: During cutaneous wound repair, platelets, dermal fibroblasts (DF) and endothelial cells all cooperate. We have presently investigated the regulation of endothelial cell tubulogenesis by human platelet thrombospondin-1 (TSP-1), in comparison to transforming growth factor-beta1 (TGF-beta1) and total platelet lysates (PL), in a fibrin matrix cell culture system incorporating DF. TSP-1, TGF-beta1 and PL all stimulated VEGF expression in DF dose dependently at mRNA and protein level. TSP-1- and PL-treated DF supernatants significantly stimulated capillary-like structure formation (tubulogenesis) by dermal microvascular endothelial cells (HMEC-1 and HDMEC), in part via VEGF, as confirmed with neutralizing anti-VEGF antibodies. In contrast, TGF-beta1-treated DF supernatants did not induce tubulogenesis. This apparent discrepancy could be explained by the differential expression regulation in HMEC-1 of fibrinolysis and metalloproteinase mediators by TSP-1 and TGF-beta1. TSP-1 potently reduced the expression of plasminogen activator inhibitor-1 (PAI-1) (mRNA and protein), whereas TGF-beta1 enhanced it. The crucial role of PAI-1 in tubulogenesis was confirmed via the addition of active recombinant PAI-1, which abrogated tubulogenesis. In contrast, neutralizing PAI-1 antibodies enhanced tubulogenesis. Our results suggest that platelet TSP-1 released in a wound stimulates endothelial cell tubulogenesis through an upregulation of DF VEGF expression and a downregulation of endothelial cell PAI-1 expression.
Experimental Cell Research 03/2007; 313(3):486-99. · 3.56 Impact Factor
[show abstract][hide abstract] ABSTRACT: Relations of mediators of inflammation and hemostasis with preclinical atherosclerosis have been poorly analyzed. The aim of this study was to test potential associations of these blood markers with indicators of cardiovascular risk and atherosclerotic burden in asymptomatic, nonsmoking, hypercholesterolemic men.
A total of 87 men underwent cardiovascular risk assessment by means of 10-year Framingham risk calculation (median 9%) and atherosclerotic burden evaluation by means of ultrasonographic measurement of common carotid intima-media thickness and assessment of atherosclerotic plaques at three arterial sites (three-site plaques).
Of the markers C-reactive protein, tumor necrosis factor-alpha, interleukin-10, factor VIIc, fibrinogen, plasminogen activator inhibitor-activator, soluble intercellular adhesion molecule-1, soluble P-selectin (sP-selectin), and von Willebrand factor, only sP-selectin was positively and independently associated with high Framingham risk score (>9%) (71.7 +/- 3.6 ng/mL, n = 33 v 59.6 +/- 2.8, n = 54; mean +/- SEM; P < .05) and with three-site plaques (75.4 +/- 5.7 ng/mL, n = 14 v 62.0 +/- 2.5, n = 73; P < .05). After adjustment for all of the above markers and for cardiovascular risk factors, odd ratios of having high Framingham risk and three-site plaques were 3.38 (1.43 to 10.21) and 5.23 (1.74 to 23.52) respectively, per 1-standard deviation increase in sP-selectin.
These results confirm that among several hemostasis and inflammation mediators, only sP-selectin blood level was associated with preclinical atherosclerosis. It might confer to sP-selectin measurement a clinical usefulness for detecting and managing high cardiovascular risk in primary prevention.
American Journal of Hypertension 10/2006; 19(10):1025-31. · 3.67 Impact Factor
[show abstract][hide abstract] ABSTRACT: In order to gain further insight on the role of Kaposi's sarcoma-associated herpesvirus (KSHV) in classic and endemic Kaposi's sarcoma (KS) pathogenesis, we aimed to determine (i) whether KSHV is detectable in peripheral blood mononuclear cells (PBMCs), (ii) which PBMCs subpopulation harbor the virus, (iii) which clinical, histologic, and immunologic parameters are associated with KSHV viremia in a population of classic and endemic KS. KSHV viremia and various immunologic parameters were screened on 81 patients. KSHV viremia was positive in 58% of the patients. KSHV was detected in B cells, T cells, and monocytes. CD34+ cells depleted in circulating endothelial cells (CECs) were never infected and 50% of the patients tested had CECs infected by KSHV. We observed a significant increase of IL-2 and IFN-gamma production by CD4 T cells and an increase of IFN-gamma production by CD8 T cells compared to control patients. KS progression (P = 0.001) and KS staging (P = 0.03) were significantly and independently associated with positive KSHV viremia. Our results show that there is no specific immunosuppression in classic or endemic KS. We showed that KSHV can be detected within CECs and that KSHV viremia could be an indicator of circulating mature or precursor spindle cells.
Journal of Investigative Dermatology 04/2006; 126(3):621-7. · 6.19 Impact Factor
[show abstract][hide abstract] ABSTRACT: Red cell (RBC) depletion is needed to bypass ABO mismatch in allogeneic bone marrow transplantation (BMT). Technical and clinical data obtained after bone marrow (BM) processing with a continuous-flow cell separator (Cobe Spectra, Gambro BCT) are reported.
RBC depletion and recovery of nucleated cells, CD3+ cells, CD34+ cells, and colony-forming unit-granulocyte-macrophage were calculated. Bacteriologic contaminations, side effects of graft infusion, and hematopoietic recovery were analyzed.
A total of 114 BM samples were processed. The mean volume collected was 1099 mL (range, 390-2450 mL). Initial and residual mean RBCs volumes were 309.9 and 4.0 mL corresponding to a depletion of 98.6 +/- 0.78 percent. Before processing, the mean numbers of nucleated cells, granulocytes, CD3+ cells, CD34+ cells, and CFU-GM were 20.28 x 10(9), 12.79 x 10(9), 1.96 x 10(9), 356.7 x 10(6), and 195.6 x 10(5), respectively. The mean corresponding recoveries after processing were 33.66, 48.98, 82.02, 82.2, and 93.9 percent. Limited side effects were observed in 14 patients without correlation with residual RBCs volume. All but two patients engrafted.
BM processing with the Cobe Spectra cell separator provides high rates of RBC depletion without significant side effects after BMT.
[show abstract][hide abstract] ABSTRACT: Although platelet-rich plasma and platelet concentrates have been used to promote bone healing in orthopaedic and maxillofacial surgery, the underlying cellular-level mechanisms remain poorly understood. The present in vitro study investigated the effects of human platelet lysate (PL) on selected functions of cultured bone cells. Cells from 18-day-old fetal rat calvaria were isolated by a collagenase digestion procedure. PL was added at different concentrations on pre- or post-confluent cell stage. After 1 day, bone cell proliferation was maximal and half-maximal in the presence of PL from 3 x 10(8) and 0.5 x 10(8) platelets/ml, respectively. During 17 h, the number of bone cells traversing the scrape border of a scrape wound model increased by 16-fold in the presence of PL from 3 x 10(8) platelets/ml. The presence of PL from 3 x 10(8) platelets/ml in pre-confluent bone cell cultures for 48 h resulted in a threefold decrease of alkaline phosphatase (ALP) specific activity. In the case of confluent bone cells, the presence of PL (from 1 x 10(6) to 3 x 10(8) platelets/ml) for 11 days, the ALP specific activity and total calcium content decreased in a PL dose-dependent manner and reached a minimum in the presence of PL from 3 x 10(8) platelets/ml. In summary, short-term PL exposure (up to 24 h) promotes the proliferative and chemotactic bone cell functions while long-term PL exposure results in a decrease of both ALP activity and mineral formation. These data show that the soluble components contained in PL may affect the bone healing process by modulating differently bone cell functions.
Clinical Oral Implants Research 11/2004; 15(5):581-8. · 3.43 Impact Factor
[show abstract][hide abstract] ABSTRACT: Pharmacological concentrations of arsenic trioxide (ATO) and organic arsenic melarsoprol induce apoptosis in malignant plasma cells. In an attempt to further document the interest of the arsenic in vivo, we treated severe combined immunodeficient (SCID) mice transplanted with human myeloma cells by ATO or melarsoprol.
Fifty-two SCID mice were irradiated before intraperitoneal (i.p.) injection of plasma cells from five myeloma patients. Engraftment was assessed by serial measurement of the human monoclonal immunoglobulin G (HuMIgG) concentration in mouse serum. Treatment with ATO (10 microg/g i.p. 5 d a week), melarsoprol (30 microg/g i.p. 5 d a week) or phosphate buffer saline was started when a sustained growth of the tumor cells was demonstrated.
Seventeen mice developed the human tumor. A significant decrease in HuMIgG amounts was observed in three of five mice of the ATO group, including two that achieved an apparent complete remission persisting up to 5 months after ATO discontinuation. In these mice, no human plasma cells were detected in tissue samples collected postmortem. Soluble human interleukin-6 receptor amount, measured in mice sera as a surrogate marker of the plasma cell proliferation, varied in parallel with HuMIgG concentration. A significant difference in survival was observed between control and ATO treated mice (113 and 158 d, respectively; P = 0.01) whereas no difference could be evidenced in control and melarsoprol groups.
Present study confirms in vivo the in vitro effects of ATO on myeloma cells. Delayed relapses were observed suggesting that prolonged or maintenance therapy has to be considered in future clinical trials. Whether or not this will translate into clinically relevant effect of the drug in myeloma patients deserves further consideration.
European Journal Of Haematology 04/2004; 72(3):166-71. · 2.55 Impact Factor
[show abstract][hide abstract] ABSTRACT: Platelet products have been proposed as adjuvant therapy for wound healing. We undertook this study to determine the healing effect of topically applied frozen autologous platelets (FAP) on chronic venous ulcers, compared with effect of placebo, and whether use of topical FAP modifies local expression of vascular endothelial growth factor (VEGF), keratinocyte growth factor (KGF), interleukin 8 (IL-8), and tissue inhibitor of metalloproteinase-1 (TIMP-1) in wound fluid.
This randomized, placebo-controlled, double-blind trial was carried out in institutional practice, with ambulatory patients with proved chronic venous leg ulcers. In all patients, whole venous blood was drawn for preparation of FAP. FAP or normal saline solution was applied three times per week for up to 12 weeks, together with hydrocolloids and standardized compression bandages. Leg ulcer surface was assessed with numerical pictures. IL-8, VEGF, KGF, and TIMP-1 levels were determined (enzyme-linked immunosorbent assay) in wound fluid after each 4 weeks of treatment.
Fifteen patients were randomized into two groups with comparable leg ulcer characteristics. Mean percent reduction in ulcer area was 26.2% in the FAP group versus 15.2% in the placebo group (P =.94). One ulcer in each group was completely healed at study end. Levels of TIMP-1 increased significantly during FAP treatment. IL-8 concentration was significantly lower in wound fluid of healing ulcers than in the fluid of nonhealing ulcers, in both FAP and placebo groups. Growth factor levels were not modified with FAP treatment.
Topical autologous platelets have no significant adjuvant effect on healing of chronic venous leg ulcers and increased wound fluid TIMP-1 concentration. Ulcer healing is associated with a decrease in wound fluid IL-8.
Journal of Vascular Surgery 01/2004; 38(6):1342-8. · 2.88 Impact Factor
[show abstract][hide abstract] ABSTRACT: Cell and tissue therapy applications in humans are being used increasingly, particularly for tissue repair. Several reconstructed skin models have been proposed. Wound healing involves overlapping steps of inflammation, cell migration and proliferation, neovascularisation, extracellular matrix production and remodelling. This is regulated by numerous cytokines and other soluble mediators. We have prepared dermal substitutes (DS) consisting of a collagen-GAG, three-dimensional matrix colonized by human dermal fibroblasts (HDF), isolated by skin explant or enzymatic digestion of the skin for potential therapeutic use in humans. To test the functionality of these DS, we measured (ELISA) the stimulatory effect on HDF in the matrix, of serial dilutions of human serum (HS) on the production of wound healing mediators: interleukin-8 (IL-8), vascular endothelial growth factor (VEGF), keratinocyte growth factor (KGF) and tissue inhibitor of metalloproteinase-1 (TIMP-1). We observed: 1). a stimulatory effect of HS on HDF production of the different mediators tested, with a dose-dependent effect in the case of IL-8 and VEGF. 2). A matrix-potentiating effect on the production of the different mediators by HDF. 3). A decrease in the production of IL-8 and VEGF when HDF isolated by enzymatic digestion was used to colonize the matrix as compared with HDF isolated by skin explant. We conclude: 1). that the production by HDF, in a collagen-GAG matrix, of mediators involved in cutaneous wound healing is decreased when HDF are isolated by enzymatic skin digestion rather than by skin explant. 2). That measurement of the production of cytokines or other mediators could be a useful quality control to test the functionality of tissue-engineered DS for tissue repair therapy in humans and more generally of cells prepared for cell therapy.
European cytokine network 01/2003; 14(1):60-4. · 1.90 Impact Factor
[show abstract][hide abstract] ABSTRACT: BACKGROUND: The mechanism of HPC mobilization in humans is unclear. In this study, the relationship between PBPC mobilization and blood levels of G-CSF, endogenous cytokines (IL-8, SCF, thrombopoietin [TPO]), and the vascular cell adhesion molecule-1 (VCAM-1) was analyzed in patients with malignancy who were undergoing a PBPC mobilization regimen.STUDY DESIGN AND METHODS: Fifty-four patients with multiple myeloma (MM) and 29 with breast cancer (BC) underwent a mobilization regimen combining conventional chemotherapy and G-CSF up to the last day of PBPC collection. The CD34+ cell count was determined on each day when leukapheresis was scheduled. Venous blood samples (n = 117) were drawn before apheresis for CD34+ cell count (flow cytometry) and cytokine (G-CSF, IL-8, SCF, TPO) and VCAM-1 measurements (ELISA).RESULTS: In multiple regression analysis, SCF was a significant determinant of CD34+ cell levels in BC patients (R = 0.50, p = 0.03) and of VCAM-1 levels in MM patients (R = 0.32, p = 0.02). SCF was negatively correlated with CD34+ cell count in patients with BC. SCF and VCAM-1 blood levels were correlated in MM and BC patients.CONCLUSION: SCF and VCAM-1 could play a role in PBPC mobilization in patients and could be useful measures by which to study patients undergoing a mobilization regimen.
[show abstract][hide abstract] ABSTRACT: We tested the immunosuppressive effect of cord blood (CB) natural killer (NK) cells using highly purified CB NK cells in mixed lymphocyte cultures (MLC) containing autologous CB T cells as responders. Control cultures were done without NK cells. Our findings revealed that CB NK cells induced a dose-dependent inhibition of T lymphocyte proliferation as evidenced by decreased 3H-thymidine incorporation in MLC. The T cell alloproliferation was significantly decreased in the presence of an NK cell to responder cell ratio of 0.1, 0.2 or 0.4 compared with control cultures done without NK cells (p=0.02, 0.003 and 0.0002, respectively). T lymphocyte inhibition was also achieved using irradiated CB NK cells and still demonstrable on addition of disparate CB NK and T cells to the MLC. In agreement with previous reports, adult blood NK cells inhibited the alloreactive T cells in the MLC using adult T lymphocytes as responders. Compared to control cultures done without NK cells, statistically significant inhibition of 3H-thymidine incorporation in MLC was observed at a ratio of NK cells to responder cells ratio of 0.2 or 0.4 (p=0.02). To investigate the mechanism whereby CB NK cells can interfere with the development of alloreactive T cells in MLC, we measured the tumour necrosis factor-alpha (TNF-alpha) concentrations in MLC supernatants using NK cell-depleted or unseparated CB mononuclear cells (MNC) as responders. The results revealed significantly high levels of TNF-alpha in the absence of NK cells (p=0.007). We conclude that CB NK cells suppress alloreactive T lymphocytes as do their counterparts in adult blood. However, the high NK to T cell ratio in CB could contribute to a more marked suppressive potential compared to that in adult blood. The mechanism of NK-mediated inhibition is likely related to disruption of the TNF-alpha pathway of T-lymphocyte activation.
European Journal Of Haematology 05/2001; 66(4):215-20. · 2.55 Impact Factor
[show abstract][hide abstract] ABSTRACT: Angiogenesis plays an important role in the growth, progression, and metastasis of solid tumors. Among angiogenic factors, basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF) appear to be useful markers in adults with cancer. The aim of this pilot study was to determine the levels of VEGF in serum and bFGF in serum and urine of children with solid tumor at diagnosis (as measured by ELISA), and to investigate whether these parameters provide prognostic information. Forty consecutive patients with different types of cancer were prospectively included in this study. Median values of all studied angiogenic factors were higher in patients than in controls (n = 40), and the differences were statistically significant for bFGF in serum and urine: 10 versus 3 pg/ml (P = 0.0004) and 6406 versus 0 pg/g of creatinine (P < 0.0001), respectively. Among patients, median serum values of bFGF and VEGF were higher in children with metastatic disease (n = 14) than in those with localized disease (n = 26). The difference was statistically significant for serum bFGF: 17.5 versus 6 pg/ml (P = 0.02). Serum angiogenic factor levels correlated with outcome. The estimated event-free survival at 3 years was 79% for patients with normal bFGF values (n = 13) versus 42% (n = 26; P = 0.02) for those with high levels, and 71% in case of normal VEGF values (n = 20) versus 38% (n = 19; P = 0.04) for those with high levels. No benefit of normal urinary bFGF values was observed. Our results provide a rationale for exploring the clinical interest of bFGF and VEGF measurements in body fluids of a larger group of children with cancer.
Clinical Cancer Research 03/2001; 7(3):538-43. · 7.84 Impact Factor
[show abstract][hide abstract] ABSTRACT: The mechanism of HPC mobilization in humans is unclear. In this study, the relationship between PBPC mobilization and blood levels of G-CSF, endogenous cytokines (IL-8, SCF, thrombopoietin [TPO]), and the vascular cell adhesion molecule-1 (VCAM-1) was analyzed in patients with malignancy who were undergoing a PBPC mobilization regimen.
Fifty-four patients with multiple myeloma (MM) and 29 with breast cancer (BC) underwent a mobilization regimen combining conventional chemotherapy and G-CSF up to the last day of PBPC collection. The CD34+ cell count was determined on each day when leukapheresis was scheduled. Venous blood samples (n = 117) were drawn before apheresis for CD34+ cell count (flow cytometry) and cytokine (G-CSF, IL-8, SCF, TPO) and VCAM-1 measurements (ELISA).
In multiple regression analysis, SCF was a significant determinant of CD34+ cell levels in BC patients (R = 0.50, p = 0.03) and of VCAM-1 levels in MM patients (R = 0.32, p = 0.02). SCF was negatively correlated with CD34+ cell count in patients with BC. SCF and VCAM-1 blood levels were correlated in MM and BC patients.
SCF and VCAM-1 could play a role in PBPC mobilization in patients and could be useful measures by which to study patients undergoing a mobilization regimen.
[show abstract][hide abstract] ABSTRACT: To characterize the cellular and molecular mechanisms underlying the efficacy of autologous platelet suspension adjuvant therapy in the treatment of macular hole.
Platelet suspensions were: paid from whole blood samples obtained from informed volunteers. For proliferation assays, platelet suspensions or purified growth factors were added to semi-confluent cultures of porcine real glial cells for 24 hours, followed by [3H]thymidine for 15 hours, after which time cells were washed, solubilized, and counted for uptake of radioactive tracer. For cell migration assays, confluent glial cultures were scrape wounded and maintained in the presence or absence of platelet suspension or identified platelet constituents. Cell migration into the denuded area was scored as a function of time. In certain cases, specific pharmacologic inhibitors of growth factor action were added at the same time as platelet adjuvant or growth factors.
Platelet suspension adjuvant induced strong mitogenic and chemotactic responses in cultured glia, in a dose-dependent manner. Maximal incorporation of thymidine was two- to threefold that of control levels, with an ED50 approximately 5 x 10(6) platelets/ml, and migration was enhanced up to 80-fold after 48 hours. Platelet suspension-induced proliferation was completely blocked by addition of 25 microM genistein, a tyrosine kinase receptor inhibitor. However, the same concentration only partially blocked the cell migration response. Addition of any single growth factor or protein identified from ELISA analysis, or a combination of all factors, did not significantly stimulate proliferation or cell migration.
Human platelet suspensions exert both proliferative and chemotactic influences on retinal glial cells in vitro, suggesting that the same responses may occur in platelet-induced macular hole repair in humans. Growth factors or proteins that have been identified within the suspensions do not mimic these responses in vitro, implying that additional currently unidentified trophic activities are also present.
[show abstract][hide abstract] ABSTRACT: To evaluate prospectively the efficacy and safety of autologous platelet concentrate (APC) as an adjuvant in surgery for idiopathic macular hole.
Multicenter, double-masked, randomized clinical trial.
Four university-based ophthalmology clinics.
One hundred ten patients with stage 3 or 4 idiopathic full-thickness macular holes of less than 3 years' duration were randomized (53 eyes to the platelet group and 57 eyes to the control group).
Standardized macular hole surgery versus surgery combined with injection of an APC. In all cases, the procedure consisted of three-port pars plana vitrectomy, posterior hyaloid separation, and nonexpansile fluid-gas exchange. After the fluid-gas exchange, patients were randomized to receive either injection of an APC or no adjunctive treatment. After surgery, patients were positioned face down for 12 days. Platelet counts showed that the concentrates contained a mean of 96.106 platelets (range, 82-102).
Anatomic and functional evaluations were performed at 1, 3, and 6 months after surgery in a double-masked fashion by an independent observer. The main outcome was reapposition of the edge of the macular hole 1 month after surgery. Secondary outcomes were anatomic status at 3 and 6 months, changes in Early Treatment Diabetic Retinopathy Study score, and complications.
One month after surgery, the anatomic success rate in the platelet group was 52 of 53 (98%; 95% confidence interval, 0.90-1.00) versus 47 of 57 (82%; 95% confidence interval, 0.70-0.91) in the control group (P = 0.009, Fisher's exact test; relative risk, 0.11; 95% confidence interval, 0.01-0.81). Visual acuity was not significantly different between the two groups at any timepoint. There were no complications specifically attributable to the platelet injection.
Injection of APC improved significantly the anatomic success rate of surgery for idiopathic macular holes of less than 3 years' duration, but postoperative visual acuity of the platelet group was not statistically different from the control group.