Stromal Cell-derived Growth Factor Research Articles

Combinatorial Use of Therapeutic ELP-Based Micelle Particles in Tissue Engineering.

Elastin-like peptides (ELPs) are a versatile platform for tissue engineering and drug delivery. Here, micelle forming ELP chains are genetically fused to three therapeutic molecules, keratinocyte growth factor (KGF), stromal cell-derived growth factor 1 (SDF1), and cathelicidin (LL37), to be used in wound healing. Chronic wounds represent a growing problem worldwide. A combinatorial therapy approach targeting different aspects of wound healing would be beneficial, providing a controlled and sustained release of active molecules, while simultaneously protecting these therapeutics from the surrounding harsh wound environment. The results of this study demonstrate that the conjugation of the growth factors KGF and SDF1 and the antimicrobial peptide LL37 to ELPs does not affect the micelle structure and that all three therapeutic moieties retain their bioactivity in vitro. Importantly, when the combination of these micelle ELP nanoparticles are applied to wounds in diabetic mice, over 90 % wound closure is observed, which is significantly higher than when the therapeutics are applied in their naked forms. The application of the nanoparticles designed here is the first report of targeting different aspect of wound healing synergistically.

Influence of anaesthetics on the production of cancer cell motogens, stromal cell‑derived factor‑1 and hepatocyte growth factor by fibroblasts

Anaesthetics have been implicated to influence cancer cells and progression. Similarly, crosstalk between cancer cells and stromal components within the microenvironment is also an important factor driving progression. Stromal cell-derived factor-1 (SDF-1) and hepatocyte growth factor (HGF) are key chemokines/cytokines produced by fibroblasts which have been established as influential factors in cancer progression. The present study explored the capacity of anaesthetics to influence the expression of these key molecules in fibroblasts. The anaesthetics rocuronium bromide (RB), vecuronium bromide (VB), suxamethonium chloride CRS (SCC), dexmedetomidine hydrochloride (DH) and lidocaine were used to treat MRC-5 fibroblasts over a range of concentrations. Following treatment, transcript expression of SDF-1 and HGF was quantified using quantitative PCR. Treatment of MRC-5 cells with RB brought about a reduction of SDF-1 expression which was found to be significant in the 45 µg/ml treatment group. Treatment with the other anaesthetics brought about some alterations in SDF-1 expression but these were not found to be statistically significant. Treatment with the tested anaesthetics did not have any significant effect on HGF transcript expression within MRC-5 cells, although again some alterations were observed. The results indicated that anaesthetics may have an impact on the fibroblast component of the tumour microenvironment, potentially influencing SDF-1 and HGF expression which in turn could influence tumour progression.

The Serine Protease Matriptase Acts As a Tumour Suppressor in Multiple Myeloma

Both in newly diagnosed multiple myeloma (MM) and during progression of the disease, malignant plasma cells are found circulating in peripheral blood as well as in the bone marrow (BM). The disseminated nature of MM is strongly dependent on the interplay between the cancer cells and the BM microenvironment, promoting myeloma cell migration in the BM. Matriptase (ST14), a type-II transmembrane serine protease primarily found in epithelial tissues, is overexpressed in a variety of human malignancies and is sufficient to induce tumour formation in mice. Frequently, a concomitant reduction in the levels of its cognate inhibitor hepatocyte growth factor activator inhibitor (HAI)-1 (SPINT1) is observed in carcinomas, while expression and function of the related inhibitor HAI-2 (SPINT2) is yet to be clarified. Dysregulated expression causing increased matriptase proteolytic activity has been associated with cancer growth, survival and metastasis. Here, we show for the first time a role of matriptase as a possible tumour suppressor in myeloma pathogenesis. Gene expression analysis of primary cells from MM patients (n=24) and human myeloma cell lines (n=8) revealed highly variable levels of matriptase, HAI-1 and HAI-2. This observation prompted us to investigate the functional role of matriptase in vitro. We showed that stable overexpression of matriptase in INA-6, a MM cell line with no endogenous ST14 expression, reduced migration by more than 50% in response to the combination of the pro-migratory cytokines stromal cell-derived factor-1 alpha (SDF-1α) and hepatocyte growth factor (HGF, Fig. 1A). Conversely, stable knockdown of matriptase in two MM cell lines with high endogenous matriptase expression (RPMI-8226 and JJN-3) significantly enhanced migration in vitro. Mechanistically, matriptase overexpression blocked activation of Src kinase (Fig. 1B), well-known as a critical player in metastasis formation promoting cancer cell motility, invasiveness and angiogenesis. In agreement with our result, previous studies have demonstrated the activation of Src family kinases (SFK) downstream SDF-1/CXCR4-signaling. Finally, we performed survival analyses in the public available MMRF CoMMpass trial database (release version IA14). Low ST14 expression was associated with significant worse overall survival (P=0.05, Fig. 1C) and progression-free survival (P=0.02, Fig. 1D). Altogether, our data are in marked contrast to the role ascribed to matriptase in epithelial and certain non-epithelial tumours as an oncogenic protein and an unfavourable prognostic marker. In conclusion, these findings suggest a novel role of matriptase as a tumour suppressor in MM pathogenesis. Disclosures Slørdahl: Celgene: Consultancy; Janssen and Celgene: Honoraria.

605-P: Endothelial-Specific Overexpression of Metallothionein Prevents Diabetes Mellitus–Induced Impairment in Ischemia Angiogenesis via Preservation of HIF-1a/SDF-1/VEGF Signaling in Endothelial Progenitor Cells

Diabetes-induced oxidative stress contributes to endothelial progenitor cells (EPCs) dysfunction and impairs endothelial regeneration. Thus, we tested whether increasing antioxidant protein metallothionein (MT) in EPCs promotes angiogenesis in a hind limb ischemia (HLI) model in endothelial-specific MT transgenic (JTMT) mice with high fat diet and streptozocin (HFD/STZ)-induced diabetes. Compared with littermate wild type (WT) diabetic mice, JTMT mice had improved blood flow recovery and angiogenesis after HLI. Similarly, transplantation of JTMT bone marrow-derived mononuclear cells (BM-MNCs) stimulated greater blood flow recovery in db/db mice with HLI than did WT BM-MNCs. The improved recovery was associated with augmented EPC function: mobilization and infiltration in JTMT mice; and, enhanced capillary EPC incorporation in db/db mice. Further, cultured JTMT-EPCs had enhanced cell survival, migration, and capillary tube formation in hypoxia/hyperglycemic conditions compared with WT-EPCs. Mechanistically, MT overexpression enhanced hypoxia-inducible factor 1α (HIF-1α), stromal cell-derived factor (SDF-1) and vascular endothelial growth factor (VEGF) expression, and reduced oxidative stress in ischemic tissues. MT’s pro-EPC effects were abrogated by siRNA knockdown of HIF-1α without affecting MT’s anti-oxidant action. These results indicate that endothelial-specific MT overexpression is sufficient to protect against diabetes-induced impairment of angiogenesis by promoting EPC functions though upregulation of HIF-1α/SDF-1/VEGF signaling and reducing oxidative stress. Disclosure K. Wang: None. X. Dai: None. J. Chen: None. F. Shen: None. K.A. Wintergerst: None. P.N. Epstein: None. L. Cai: None. Y. Tan: None. Funding American Diabetes Association (1-11-BS-017, 1-15-BS-018 to L.C.)

In Situ Support of ILC Precursors

Innate lymphoid cells (ILCs) are tissue-resident lymphocytes that promote immunity to pathogens at mucosal barriers, but the mechanisms regulating their development within tissues remain poorly understood. In this issue of Immunity, Oherle etal. identify a niche in the neonatal airway where stromal cell-derived insulin-like growth factor 1 (IGF1) supports the proliferation of ILC precursors and protects from infection.

Platelet‑derived growth factor‑BB promotes proliferation and migration of retinal microvascular pericytes by up‑regulating the expression of C‑X‑C chemokine receptor types 4

Stromal cell-derived growth factor (SDF)-1α acts as a ligand to C-X-C chemokine receptors 4 (CXCR4) and 7 (CXCR7), which are involved in the formation of choroidal neovascularization. Previous studies have demonstrated crosstalk between the platelet-derived growth factor (PDGF)-BB/PDGF receptor (PDGFR)-β and SDF-1α/CXCR4 axes during tumor neovascularization by increasing the recruitment of pericytes. However, the effects of interactions between these two signaling pathways in retinal microvascular pericytes remain poorly understood. Western blotting and reverse transcription-quantitative PCR were used to measure CXCR4 and CXCR7 expression in PDGF-BB-treated pericytes, whilst Cell Counting Kit-8 and Transwell migration assays were used to investigate cell viability and migration following PDGF-BB pretreatment on SDF-1α-treated pericytes. Exogenous PDGF-BB enhanced CXCR4 and CXCR7 expression through PDGFR-β in a dose- and time-dependent manners. In addition, PDGF-BB increased cell viability and migration in SDF-1α-treated pericytes, which were inhibited by AMD3100 and niclosamide, inhibitors for CXCR4 and STAT3 respectively. Crosstalk between PDGF-BB/PDGFR-β and SDF-1α/CXCR4/CXCR7 were involved in the JAK2/STAT3 signaling pathway. PDGF-BB treatment enhanced CXCR4, CXCR7 and PDGFR-βexpression, which may be associated with the phosphorylation of STAT3. siRNA-PDGFR-β transfection reduced CXCR4 and CXCR7 expression in pericytes. Therefore, PDGF-BB directly targets PDGFR-β and serves an important role in regulating CXCR4 and CXCR7 expression, ultimately affecting viability and migration in SDF-1α-treated pericytes. Therefore, targeting CXCR4/CXCR7 may serve as a potential therapeutic strategy for fundus diseases.

Valproic acid stimulates in vitro migration of the placenta-derived mesenchymal stem/stromal cell line CMSC29.

The placenta is an abundant source of mesenchymal stem/stromal cells (MSC), but our understanding of their functional properties remains limited. We previously created a placental-derived chorionic MSC (CMSC) cell line to overcome the difficulties associated with conducting extensive ex vivo optimization and experimental work on primary cells. The aim of this study was to characterize the migratory behavior of the CMSC29 cell line in vitro. Stimulators of MSC migration, including two cytokines, stromal cell-derived factor-1α (SDF-1α) and hepatocyte growth factor (HGF), and a pharmacological agent, valproic acid (VPA), were tested for their ability to stimulate CMSC29 cell migration. Assessment of cell migration was performed using the xCELLigence Real-Time Cell Analyzer (RTCA). There was no significant increase in CMSC29 cell migration towards serum free medium with increasing concentration gradients of SDF-1α or HGF. In contrast, treating CMSC29 cells with VPA alone significantly increased their migration towards serum free medium. Immortalized CMSC29 cells retain important properties of primary CMSC, but their migratory properties are altered. CMSC29 cells do not migrate in response to factors that reportedly stimulate primary MSC/CMSC migration. However, CMSC29 increase their migration in response to VPA treatment alone. Further studies are needed to determine the mechanism by which VPA acts alone to stimulate CMSC29 migration. Still, this study provides evidence that VPA pre-treatment may improve the benefits of cell-based therapies that employ certain MSC sub-types.

Effects of bone marrow mesenchymal stem cell transplantation on the expression of stromal cell-derived factor-1α and vascular endothelial growth factor in rats with acute hepatic failure

Objective: To investigate the curative effect of bone marrow mesenchymal stem cells (BMSCs) transplantation on the expression of stromal cell-derived growth factor (SDF-1 α) and vascular endothelial growth factor (VEGF) in rats with acute hepatic failure, and to compare the effects of two transplantation pathways. Methods: Eighty-four rats with acute liver failure (ALF) induced by D-galactosamine combined with lipopolysaccharide were randomly divided into control group, tail vein and portal vein transplantation group. The latter two groups were injected allogenic BMSCs into the tail vein and portal vein. Blood samples and liver tissue samples were collected at 24, 72, 120, and 168h after transplantation to detect serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST). The improvement of liver function before and after BMSCs transplantation was compared. The expression of VEGF and SDF-1a in liver tissue was detected by immunofluorescence and Western blot. Data measurement between two groups was performed by analysis of variance and the correlation analysis was performed by Spearman's rank correlation coefficient. Results: Serum ALT and AST levels in the tail vein and portal vein transplantation group peaked at 24 h after transplantation, which were (134.60 ± 58.08 IU/L), (179.20 ± 86.68 IU/L), and (131.00 ± 54.47 IU/L), (173.50 ± 93.10 IU/L). In addition, 168h after transplantation it decreased to (46.10 ± 8.40 IU/L), (95.67 ± 13.80 IU/L) and (19.30 ± 1.30 IU/L), (54.30 ± 6.00 IU/L). After 120 and 168 hours of BMSCs transplantation, the levels of serum ALT and AST in tail vein and portal vein transplantation group were significantly higher than control group (F ≥ 12.51, P < 0.01). The results of western blot and immunofluorescence showed that the expression levels of SDF-1α and VEGF protein in the two BMSCs transplantation groups increased with the improvement of liver function, and the difference was statistically significant at 120 and 168 hours after transplantation (F ≥ 9.069, P < 0.05). There was no significant difference in the expression of SDF-1a and VEGF between the tail vein and portal vein transplantation groups (P > 0.05). Correlation analysis showed that the expression levels of SDF-1α and VEGF in liver tissues were positively correlated (r = 0.923, P < 0.05). Conclusion: BMSCs transplantation can promote the secretion of VEGF for recovery of liver function to reduce the degree of inflammation and necrosis in rats with ALF.

Cigarette Smoking Impairs Adipose Stromal Cell Vasculogenic Activity and Abrogates Potency to Ameliorate Ischemia.

Cigarette smoking (CS) adversely affects the physiologic function of endothelial progenitor, hematopoietic stem and progenitor cells. However, the effect of CS on the ability of adipose stem/stromal cells (ASC) to promote vasculogenesis and rescue perfusion in the context of ischemia is unknown. To evaluate this, ASC from nonsmokers (nCS-ASC) and smokers (CS-ASC), and their activity to promote perfusion in hindlimb ischemia models, as well as endothelial cell (EC) survival and vascular morphogenesis in vitro were assessed. While nCS-ASC improved perfusion in ischemic limbs, CS-ASC completely lost this therapeutic effect. In vitro vasculogenesis assays revealed that human CS-ASC and ASC from CS-exposed mice showed compromised support of EC morphogenesis into vascular tubes, and the CS-ASC secretome was less potent in supporting EC survival/proliferation. Comparative secretome analysis revealed that CS-ASC produced lower amounts of hepatocyte growth factor (HGF) and stromal cell-derived growth factor 1 (SDF-1). Conversely, CS-ASC secreted the angiostatic/pro-inflammatory factor Activin A, which was not detected in nCS-ASC conditioned media (CM). Furthermore, higher Activin A levels were measured in EC/CS-ASC cocultures than in EC/nCS-ASC cocultures. CS-ASC also responded to inflammatory cytokines with 5.2-fold increase in Activin A secretion, whereas nCS-ASC showed minimal Activin A induction. Supplementation of EC/CS-ASC cocultures with nCS-ASC CM or with recombinant vascular endothelial growth factor, HGF, or SDF-1 did not rescue vasculogenesis, whereas inhibition of Activin A expression or activity improved network formation up to the level found in EC/nCS-ASC cocultures. In conclusion, ASC of CS individuals manifest compromised in vitro vasculogenic activity as well as in vivo therapeutic activity. Stem Cells 2018;36:856-867.

Stromal Cell-Derived Growth Factor-1 Alpha-Elastin Like Peptide Fusion Protein Promotes Cell Migration and Revascularization of Experimental Wounds in Diabetic Mice.

Objective: In previous work, we demonstrated the development of a novel fusion protein containing stromal cell-derived growth factor-1 alpha juxtaposed to an elastin-like peptide (SDF1-ELP), which has similar bioactivity, but is more stable in elastase than SDF1. Herein, we compare the ability of a single topical application of SDF1-ELP to that of SDF1 in healing 1 × 1 cm excisional wounds in diabetic mice. Approach: Human Leukemia-60 cells were used to demonstrate the chemotactic potential of SDF1-ELP versus SDF1 in vitro. Human umbilical vascular endothelial cells were used to demonstrate the angiogenic potential of SDF1-ELP versus SDF1 in vitro. The bioactivity of SDF1-ELP versus SDF1 after incubation in ex-vivo diabetic wound fluid was compared. The in-vivo effectiveness of SDF1-ELP versus SDF1 was compared in diabetic mice wound model by monitoring for the number of CD31+ cells in harvested wound tissues. Results: SDF1-ELP promotes the migration of cells and induces vascularization similar to SDF1 in vitro. SDF1-ELP is more stable in wound fluids compared to SDF1. In vivo, SDF1-ELP induced a higher number of vascular endothelial cells (CD31+ cells) compared to SDF1 and other controls, suggesting increased vascularization. Innovation: While growth factors have been shown to improve wound healing, this strategy is largely ineffective in chronic wounds. In this work, we show that SDF1-ELP is a promising agent for the treatment of chronic skin wounds. Conclusion: The superior in vivo performance and stability of SDF1-ELP makes it a promising agent for the treatment of chronic skin wounds.

The development and characterization of SDF1α-elastin-like-peptide nanoparticles for wound healing

Chronic skin wounds are characterized by poor re-epithelialization, angiogenesis and granulation. Previous work has demonstrated that topical stromal cell-derived growth factor-1 (SDF1) promotes neovascularization, resulting in faster re-epithelialization of skin wounds in diabetic mice. However, the clinical usefulness of such bioactive peptides is limited because they are rapidly degraded in the wound environment due to high levels of proteases. Here, we describe the development of a recombinant fusion protein comprised of SDF1 and an elastin-like peptide that confers the ability to self-assemble into nanoparticles. The fusion protein and recombinant human SDF1 showed similar binding characteristics, as indicated by the measured equilibrium dissociation constant (Kd) for the binding of free SDF1 or the fusion protein to the CXCR4 receptor. The biological activity of SDF1-ELP, as measured by intracellular calcium release in HL60 cells was dose dependent, and also very similar to that of free SDF1. In contrast, the biological activity of SDF1-ELP in vivo was significantly superior to that of free SDF1. When applied to full thickness skin wounds in diabetic mice, wounds treated with SDF1-ELP nanoparticles were 95% closed by day 21, and fully closed by day 28, while wounds treated with free SDF1, ELP alone, or vehicle were only 80% closed by day 21, and took 42days to fully close. In addition, the SDF1-ELP nanoparticles significantly increased the epidermal and dermal layer of the healed wound, as compared to the other groups. These results indicate that SDF1-ELP fusion protein nanoparticles are promising agents for the treatment of chronic skin wounds.

Therapeutic Delivery of Stromal Cell-Derived Factor-1 for Injury Repair

Stromal cell-derived growth factor-1 (SDF1) is a chemokine that is over-expressed at sites of injury and is believed to play an important role in wound repair. At the cellular level, SDF1 regulates the mobilization and trafficking of endothelial progenitors that originate in the bone marrow and functionally contribute to neovascularization and angiogenesis in the wound. Consequently, SDF1 is a potentially interesting therapeutic with the potential to enhance these processes in acute and chronic injuries that otherwise tend to heal poorly, such as spinal cord injury, stroke, myocardial infarction, diabetic skin wounds and acute burns. However, the therapeutic usefulness of SDF1, as many other similar peptide-based growth factors and chemokines, is severely limited due to its short in vivo half-life, as it is rapidly degraded by proteases, which are typically very abundant at the wound site. Several studies have reported methodologies to increase SDF1 in vivo stability by mutating the protease cleavage sites of the molecule. Another approach has been to incorporate the chemokine into biomaterials that shield it from degradation. Yet another approach would be to develop a system that is inherently stable and could be combined with these aforementioned strategies. For example, self-assembled nanoparticles could shield SDF1 (or one of its forms engineered to be more resistant to proteolysis) from proteolysis and then be incorporated into suitable biomaterials. Nanotechnology-based delivery systems have however been used to a very limited extent for SDF1. This paper aims to provide a summary of the various stabilization and delivery methods available for SDF1, some of which have been already used, as well as others that have been used with other bioactive peptides, but would be potentially applicable to SDF1.

Compound K attenuates stromal cell-derived growth factor 1 (SDF-1)-induced migration of C6 glioma cells

BACKGROUND/OBJECTIVESStromal cell-derived growth factor 1 (SDF-1), also known as chemokine ligand 12, and chemokine receptor type 4 are involved in cancer cell migration. Compound K (CK), a metabolite of protopanaxadiol-type ginsenoside by gut microbiota, is reported to have therapeutic potential in cancer therapy. However, the inhibitory effect of CK on SDF-1 pathway-induced migration of glioma has not yet been established.MATERIALS/METHODSCytotoxicity of CK in C6 glioma cells was determined using an EZ-Cytox cell viability assay kit. Cell migration was tested using the wound healing and Boyden chamber assay. Phosphorylation levels of protein kinase C (PKC)α and extracellular signal-regulated kinase (ERK) were measured by western blot assay, and matrix metallopeptidases (MMP) were measured by gelatin-zymography analysis.RESULTSCK significantly reduced the phosphorylation of PKCα and ERK1/2, expression of MMP9 and MMP2, and inhibited the migration of C6 glioma cells under SDF-1-stimulated conditions.CONCLUSIONSCK is a cell migration inhibitor that inhibits C6 glioma cell migration by regulating its downstream signaling molecules including PKCα, ERK1/2, and MMPs.

FRI-024 - Splenectomy Amplify the Therapeutic Potential of Adipose Tissue-Derived Mesenchymal Stem Cells via Stromal Cell-Derived Factor-1 and Hepatocyte Growth Factor

FRI-024 - Splenectomy Amplify the Therapeutic Potential of Adipose Tissue-Derived Mesenchymal Stem Cells via Stromal Cell-Derived Factor-1 and Hepatocyte Growth Factor

Therapeutic Delivery of Stromal Cell-Derived Factor-1 for Injury Repair

Stromal cell-derived growth factor-1 (SDF1) is a chemokine that is over-expressed at sites of injury and is believed to play an important role in wound repair. At the cellular level, SDF1 regulates the mobilization and trafficking of endothelial progenitors that originate in the bone marrow and functionally contribute to neovascularization and angiogenesis in the wound. Consequently, SDF1 is a potentially interesting therapeutic with the potential to enhance these processes in acute and chronic injuries that otherwise tend to heal poorly, such as spinal cord injury, stroke, myocardial infarction, diabetic skin wounds and acute burns. However, the therapeutic usefulness of SDF1, as many other similar peptide-based growth factors and chemokines, is severely limited due to its short in vivo half-life, as it is rapidly degraded by proteases, which are typically very abundant at the wound site. Several studies have reported methodologies to increase SDF1 in vivo stability by mutating the protease cleavage site...

Splenectomy enhances the therapeutic effect of adipose tissue-derived mesenchymal stem cell infusion on cirrhosis rats.

Clinical studies suggest that splenectomy improves liver function in cirrhotic patients, but the influence of splenectomy on stem cell transplantation is poorly understood. This study investigated the effect ofsplenectomy on stem cell infusion and elucidated its mechanism. Rat adipose tissue-derived mesenchymal stem cells were infused into cirrhosis rats with or without splenectomy, followed by the assessment of the invivo distribution of stem cells and pathological changes. Stromal cell-derived factor-1 and hepatocyte growth factor expression were also investigated in splenectomized cirrhosis patients and rats. Splenectomy, prior to cell infusion, improved liver function and suppressed fibrosis progression more efficiently than cell infusion alone in the experimental cirrhosis model. Stromal cell-derived factor-1 and hepatocyte growth factor levels after splenectomy were increased in patients and rats. These upregulated cytokines significantly facilitated stem cell motility, migration and proliferation invitro. C-X-C chemokine receptor type 4 neutralization weakened the promotion of cell migration by these cytokines. The infused cells integrated into liver fibrosis septa and participated in regeneration more efficiently in splenectomized rats. Direct coculture with stem cells led to inhibition of hepatic stellate cell proliferation. In addition, hepatocyte growth factor induced hepatic stellate cell apoptosis via the c-jun N-terminal kinase-p53 pathway. Splenectomy prior to cell infusion enhanced the therapeutic effect of stem cells on cirrhosis, which involved upregulation of stromal cell-derived factor-1 and hepatocyte growth factor after splenectomy.

CSF biomarkers of monocyte activation and chemotaxis correlate with magnetic resonance spectroscopy metabolites during chronic HIV disease.

Human immunodeficiency virus (HIV)-associated neurocognitive disorders (HAND) persist despite combination antiretroviral therapy (cART), supporting the need to better understand HIV neuropathogenesis. Magnetic resonance spectroscopy (MRS) of the brain has demonstrated abnormalities in HIV-infected individuals despite cART. We examined the associations between MRS metabolites and selected cerebrospinal fluid (CSF) biomarkers reflecting monocyte/macrophage activation and chemotaxis. A multicenter cross-sectional study involving five sites in the USA was conducted. The following CSF biomarkers were measured: soluble CD14 (sCD14), monocyte chemotactic protein-1 (MCP-1), interferon inducible protein 10 (IP-10), and stromal cell-derived growth factor 1 alpha (SDF-1α). The following MRS metabolites were measured from basal ganglia (BG), frontal white matter (FWM), and frontal gray matter (FGM): N-acetylaspartate (NAA), myo-inositol (MI), choline (Cho), and creatine (Cr). CSF biomarkers were compared to absolute MRS metabolites as well as metabolite/Cr ratios using linear regression. Eighty-three HIV-infected individuals were included, 78 % on cART and 37 % with HAND. The most robust positive correlations were between MCP-1 and Cho in BG (R (2) 0.179, p < 0.001) as well as MCP-1 and MI in FWM (R (2) 0.137, p = 0.002). Higher Cr levels in FWM were associated with MCP-1 (R (2) 0. 075, p = 0.01) and IP-10 (R (2) 0.106, p = 0.003). Comparing biomarkers to MRS metabolite/Cr ratios impacted some relationships, e.g., higher sCD14 levels were associated with lower Cho/Cr ratios in FGM (R (2) 0.224, p < 0.001), although higher MCP-1 levels remained associated with Cho/Cr in BG. These findings provide evidence that monocyte activation and chemotaxis continue to contribute to HIV-associated brain abnormalities in cART-treated individuals.

Combined treatment with paclitaxel and suramin prevents the development of metastasis by inhibiting metastatic colonization of circulating tumor cells.

Metastatic disease accounts for most deaths due to breast cancer and thus identification of novel ways to prevent this complication remains a key goal. A frequently employed preclinical model of breast cancer metastasis relies on xenografted human MDA-MB-231 cells, since these reliably produce both soft tissue and osseous metastases when introduced into the arterial circulation of athymic mice. Herein, we explored the ability of suramin (SA), an agent shown to antagonize the effects of various stromal cell-derived growth factors relevant to bone marrow colonization of tumor cells, administered both with and without paclitaxel (PTX), to inhibit the development of MDA-MB-231 metastases. Treatment with SA, PTX, or PTX plus SA (PTX/SA) was begun either at day-1, or 7days after intra-arterial inoculation of luciferase-expressing MDA-MB-231-luc2 cells. Using in vivo and ex vivo bioluminescence imaging to detect macro-metastases, we found that PTX/SA treatment initiated on day-1 was able to dramatically reduce the frequency of bone metastases. PTX/SA and PTX administration commenced at day 7, in contrast, had no significant effect on the frequency of bone metastases, but exerted a relatively modest inhibitory effect on growth of metastases. Interestingly, reminiscent of what is seen clinically in anti-HER2 treated individuals, several of the PTX/SA-treated long term survivors went on to develop late onset CNS metastasis. Our results suggest that combining SA with PTX either in an adjuvant setting or during medical interventions that can increase the numbers of circulating tumour cells might be an effective way to prevent the development of metastases.

Differential expressions of stromal cell-derived factor-1α and vascular endothelial growth factor in the placental bed of pregnancies complicated by preeclampsia

Objective: The aim of this study is to examine the differential expression of stromal cell-derived factor-1α (SDF-1α)/CXCR4 and vascular endothelial growth factor (VEGF) in the third trimester placental bed of normotensive controls and preeclamptic patients. Methods: Placental bed tissues were collected from 15 patients with preeclampsia (PE) and 15 gestational-matched normotensive controls at the time of their cesarean delivery. Placental bed expressions of SDF-1α, CXCR4 and VEGF were evaluated by reverse transcriptase-polymerase chain reaction (RT-PCR), real-time PCR and immunohistochemical staining. Results: No statistical difference was found between the PE and the normotensive control group with respect to their age and parity, gravidity and body mass index. The placental bed expressions of SDF-1α/CXCR4 and VEGF were significantly decreased in the PE group compared with the normotensive control group. Conclusions: This study showed decreased expressions of SDF-1α/CXCR4 and VEGF in the third trimester placental bed of pregnancies with PE. This result suggests that decreased expressions of SDF-1α/CXCR4 and VEGF in the placental bed could be associated with the pathogenesis of PE.

Paracrine activation of hepatic stellate cells in platelet‐derived growth factor C transgenic mice: Evidence for stromal induction of hepatocellular carcinoma

Cirrhosis is the primary risk factor for the development of hepatocellular carcinoma (HCC), yet the mechanisms by which cirrhosis predisposes to carcinogenesis are poorly understood. Using a mouse model that recapitulates many aspects of the pathophysiology of human liver disease, we explored the mechanisms by which changes in the liver microenvironment induce dysplasia and HCC. Hepatic expression of platelet-derived growth factor C (PDGF-C) induces progressive fibrosis, chronic inflammation, neoangiogenesis and sinusoidal congestion, as well as global changes in gene expression. Using reporter mice, immunofluorescence, immunohistochemistry and liver cell isolation, we demonstrate that receptors for PDGF-CC are localized on hepatic stellate cells (HSCs), which proliferate, and transform into myofibroblast-like cells that deposit extracellular matrix and lead to production of growth factors and cytokines. We demonstrate induction of cytokine genes at 2 months, and stromal cell-derived hepatocyte growth factors that coincide with the onset of dysplasia at 4 months. Our results support a paracrine signaling model wherein hepatocyte-derived PDGF-C stimulates widespread HSC activation throughout the liver leading to chronic inflammation, liver injury and architectural changes. These complex changes to the liver microenvironment precede the development of HCC. Further, increased PDGF-CC levels were observed in livers of patients with nonalcoholic fatty steatohepatitis and correlate with the stage of disease, suggesting a role for this growth factor in chronic liver disease in humans. PDGF-C transgenic mice provide a unique model for the in vivo study of tumor-stromal interactions in the liver.