Microfluidic Cards Research Articles

MiRNA Signature of Hepatocellular Carcinoma Vascularization: How the Controls Can Influence the Signature.

miRNA deregulation and vascular modifications constitute promising predictors in the study of hepatocellular carcinoma (HCC). In the literature, the relative miRNA abundance in HCC is usually determined using as control non-matched tumoral tissue, healthy liver, or cirrhotic liver. However, a common standard RNA control for the normalization toward the tissue gene expression was not settled yet. To assess the differences existing in the quantitative miRNA gene expression in HCC on tissue according to two different liver controls. A wide array of miRNAs was analyzed on 22 HCCs arisen in cirrhotic and non-cirrhotic livers by means of microfluidic cards. Control samples included total RNA extracted from healthy and cirrhotic livers. Immunohistochemistry for CD34 and Nestin was performed to assess the pattern of intratumoral vascular modifications. Six miRNAs were deregulated in HCCs using either controls: miR-532, miR-34a, miR-93, miR-149#, miR-7f-2#, and miR-30a-5p. Notably, the miRNA expression changed significantly between HCCs arisen in cirrhotic and non-cirrhotic livers, according to the control used for normalization. Different miRNA profiles were found also in HCCs with different vascular patterns, according to the control used for normalization. Our data confirm that the choice of the methodology, and particularly the control used for normalization, represents the main concern in miRNA evaluation, particularly in a heterogeneous model such as liver pathology. Still we observed the deregulation of some common miRNAs as promising in HCC cancerogenesis and progression. A standardized control will be a crucial achievement to compare miRNA expression among different laboratories.

Analysis of miRNA expression profile induced by short term starvation in breast cancer cells treated with doxorubicin.

Recent studies showed that dietary approaches restricting food intake can be helpful to hinder tumor progression. To date, the molecular mechanisms are unclear and a key role seems to be exerted by nutrient-related signaling pathways. Since several evidences showed that non-coding small RNAs, including microRNAs, are correlated to cancer progression and antiblastic treatment response, our work aims to study their involvement in a triple negative breast cancer (TNBC) cell line treated with doxorubicin under Short Term Starvation (STS) condition.Human TNBC cell line MDA-MB-231 and healthy breast cell line MCF10A were treated with 1 μM doxorubicin for 24 h under STS condition for 48 h and miRNA expression profiles were analyzed using Taqman® Low Density Array A human microRNA microfluidic cards. In addition, the expression of specific mRNAs and miRNAs differentially expressed under STS was analyzed using Real-time PCR analyses.MiRNA expression profile analysis in MDA-MB-231 and MCF10A cells treated with doxorubicin under STS for 48 h could explain the molecular mechanisms underlying anticancer effects associated to STS. Among deregulated miRNAs, a subset, including miR-15b, miR-23a, miR-26a, miR-29a, miR-106b, miR-128, miR-149, miR-181a, miR-192, miR-193b, miR-195, miR-324-3p and miR-494, has been shown to be involved in pathways related to drug sensitivity/resistance.The obtained data from our study suggest a potential involvement of some miRNAs in molecular pathways mediating the anticancer effects of STS in doxorubicin-treated breast cancer cells. Preliminary results seem to be encouraging and, in future, could allow the discovery of new potential targets useful for the development of new therapeutic approaches.

Microfluidic Extreme PCR: <1 Minute DNA Amplification in a Thin Film Disposable

Point-of-care diagnostic testing using PCR requires a device that is fast, economical, and practical. Sub-minute amplification has been demonstrated using high concentrations of primers and polymerase in glass capillaries, but its platform is limited to research use. A system using heated copper blocks to clamp a microfluidic flow-through PCR card fabricated from thin film polycarbonate was modeled, fabricated, and tested. Models show that fluid flowing through a thin-film device clamped between temperature-controlled copper blocks equilibrates to a temperature change in 250 milliseconds. A 2-step, 35 cycle PCR with 1.06 second cycles specifically amplified a 69-base pair fragment from a 450-base pair synthetic DNA template of random sequence with the same performance as the glass capillary system. This system demonstrates the feasibility of <1 minute PCR in an inexpensive, disposable sample container.

Extracellular Vesicles Play an Important Role in Intercellular Communication Between Bone Marrow Stroma and Hematopoietic Progenitor Cells in Myeloproliferative Neoplasms

The complex interplay between bone marrow-derived mesenchymal stromal cells (BM-MSC) and neoplastic hematopoietic cells is involved in the progression of myeloproliferative neoplastic (MPN) diseases. Extracellular vesicles (EV) have emerged as a complex cell-to-cell communication system within the neoplastic microenvironment. EV are able to reprogram recipient cells by transferring proteins, mRNA and microRNA from their cell of origin. We aimed to analyze the microRNA content of EV obtained from MPN BM-MSC, as well as the changes induced when these EV are incorporated into hematopoietic progenitor cells (HPC).EV were isolated from BM-MSC of MPN patients (n=22) and healthy donors (HD) (n=19) by ultracentrifugation. Characterization of EV by transmission electron microscopy (TEM), immunoblot, multiparametric flow cytometry (MFC) and NanoSight analysis revealed vesicles with a typical bilayer-membrane characteristic morphology with a size inferior to 500 nm, which were positive for various EV markers as CD63 and CD81, and for MSC markers as CD73, CD90 and CD44 (Figure 1). MicroRNA profiling by 384-well microfluidic cards (TaqMan® MicroRNA Array A) showed an overall increase in the microRNA expression in the MPN-MSC-derived EV, when compared to EV from donor MSC. Using RT-PCR, we observed that miR-155 was selectively enriched in EV released by MPN-MSC. An overexpression of this microRNA was observed in EV (p=0.032), while a downregulation was observed in BM-MSC (p=0.0078) (Figure 2).EV incorporation was demonstrated by fluorescence microscopy and MFC, where HPC (CD34+ cells obtained by immunomagnetic selection) were co-cultured with Vybrant Dil-labeled EV. For functional studies apoptosis and clonogenic assays (CFU-GM) were performed. We observed an increase in CD34+ cell viability after incorporating EV from BM-MSC (HD and MPN). Moreover, an increase (p=0.04) in miR-155 expression was observed when HD HPC incorporated EV from MPN-MSC. When neoplastic CD34+ cells incorporated the EV derived from MPN-MSC an increase of CFU-GM number was also observed.We suggest that EV released from MPN-MSC represent a mechanism of intercellular communication between malignant stromal and hematopoietic cells, through the transfer of genetic information that may be relevant in the pathophysiology of these diseases.Funding: GRS 1034/A/14 (C. Sanidad, JCYL) and FCT (SFRH/BD/86451/2012) [Display omitted] [Display omitted] DisclosuresSánchez-Guijo:Bristol-Myers-Squib: Consultancy, Honoraria; Novartis: Consultancy, Honoraria; Pfizer: Consultancy, Honoraria; Incyte: Consultancy, Honoraria. Del Cañizo:Celgene: Membership on an entity’s Board of Directors or advisory committees, Research Funding; Jansen-Cilag: Membership on an entity’s Board of Directors or advisory committees, Research Funding; Arry: Membership on an entity’s Board of Directors or advisory committees, Research Funding; Novartis: Membership on an entity’s Board of Directors or advisory committees, Research Funding.

Determination of equilibrium dissociation constants for recombinant antibodies by high-throughput affinity electrophoresis.

High-quality immunoreagents enhance the performance and reproducibility of immunoassays and, in turn, the quality of both biological and clinical measurements. High quality recombinant immunoreagents are generated using antibody-phage display. One metric of antibody quality – the binding affinity – is quantified through the dissociation constant (KD) of each recombinant antibody and the target antigen. To characterize the KD of recombinant antibodies and target antigen, we introduce affinity electrophoretic mobility shift assays (EMSAs) in a high-throughput format suitable for small volume samples. A microfluidic card comprised of free-standing polyacrylamide gel (fsPAG) separation lanes supports 384 concurrent EMSAs in 30 s using a single power source. Sample is dispensed onto the microfluidic EMSA card by acoustic droplet ejection (ADE), which reduces EMSA variability compared to sample dispensing using manual or pin tools. The KD for each of a six-member fragment antigen-binding fragment library is reported using ~25-fold less sample mass and ~5-fold less time than conventional heterogeneous assays. Given the form factor and performance of this micro- and mesofluidic workflow, we have developed a sample-sparing, high-throughput, solution-phase alternative for biomolecular affinity characterization.

Persistent Alterations in Microglial Enhancers in a Model of Chronic Pain.

Chronic pain is a common and devastating condition that induces well-characterized changes in neurons and microglia. One major unanswered question is why these changes should persist long after the precipitating injury has healed. Here, we suggest that some of the longer-lasting consequences of nerve injury may be hidden in the epigenome. Cell sorting and sequencing techniques were used to characterize the spinal cord immune response in a mouse model of chronic neuropathic pain. Infiltration of peripheral myeloid cells was found to be absent, and RNA sequencing (RNA-seq) of central microglia revealed transient gene expression changes in response to nerve ligation. Conversely, examination of microglial enhancers revealed persistent, post-injury alterations in close proximity to transcriptionally regulated genes. Enhancers are regions of open chromatin that define a cell's transcription factor binding profile. We hypothesize that changes at enhancers may constitute a mechanism by which painful experiences are recorded at a molecular level.

Increased microRNA-323-3p in IL-22/IL-17-producing T cells and asthma: a role in the regulation of the TGF-β pathway and IL-22 production.

IL-22- and IL-17-producing T cells have important roles in allergic diseases. MicroRNAs (miRNAs) are posttranscriptional regulators of gene expression and modulate numerous biological processes. Little is known about the functions of miRNAs in IL-22/IL-17-producing T cells. IL-22- and IL-17-positive T cells were sorted from human peripheral blood mononuclear cells (PBMCs) by intracellular staining and dual-secretion assay. miRNA expression profiles were detected with TaqMan array microfluidic cards. T cells were transfected with miRNA mimics. Gene expression was analyzed using RT-qPCR and/or enzyme-linked immunosorbent assay in T-cell subsets and PBMCs from patients with asthma and atopic dermatitis. The increased expression of miR-323-3p and noncoding RNA nc886 and reduced expression of miR-93, miR-181a, miR-26a, and miR-874 were detected in IL-22-producing T cells. The pathway analysis of the putative targets suggested that these differentially expressed miRNAs could impact the proliferation, differentiation, and effector functions of T cells. Further analyses showed the highest expression for miR-323-3p in IL-22- and IL-17-double-positive T cells and its capacity to suppress multiple genes from the transforming growth factor-β pathway and the production of IL-22 in T cells. An increased expression of miR-323-3p in PBMCs from patients with asthma and reverse correlation between miR-323-3p levels and IL-22 production in PBMCs cultured in T-cell growth conditions was observed. Our data suggest that miR-323-3p acts in a negative feedback loop to control the production of IL-22 in IL-22/IL-17-producing T cells and might thus impact the T-cell responses in asthma.

A Rapid, Self-confirming Assay for HIV: Simultaneous Detection of Anti- HIV Antibodies and Viral RNA

ObjectiveWe developed a microfluidic system to simultaneously detect host anti-HIV antibodies and viral RNA in the same specimen in order to satisfy two important diagnostic criteria, especially within resource-limited settings. First, the system can detect acute HIV infection and allow immediate confirmation of a seropositive screening result by detection of HIV RNA. It also addresses the well-known "seroconversion window" during early HIV infection when antibodies are not yet detectable and viral loads are at their highest.MethodsWe first developed and optimized two separate manual assays for the detection of host anti-HIV antibodies and viral RNA and then converted them to the microfluidic system. We optimized a commercially available serologic assay to run within the microfluidic device while we incorporated the isothermal LAMP assay to detect the presence of viral RNA. The microfluidic device and instrumentation were developed to simultaneously perform both assays without any user intervention.ResultsThe finalized system consists of a disposable injection molded and film-laminated microfluidic CARD disposable device and a portable, software controlled instrument, which together can automatically perform all steps of both assays without any user intervention after the initial loading of samples and reagents. The microfluidic CARD cartridge has multiple microchannels, valves, pumps and reservoirs, which perform the immunoassay, isolates viral RNA for detection by magnetic bead based purification, and Reverse Transcriptase loop-mediated isothermal amplification (RT-LAMP). The microfluidic system was able to detect host anti-HIV antibodies and viral RNA in either a blood or saliva sample.ConclusionThe ability to detect antibodies and simultaneously confirm a seropositive HIV-RNA result provides healthcare workers with a complete and accurate appraisal of a patient's infection status in the earliest stages of the disease and represents an important tool for the "Test and Treat" and "Treatment as Prevention" approaches for controlling the HIV epidemic.

T-Cell Defect in Diffuse Large B-Cell Lymphomas Involves Expansion of Myeloid Derived Suppressor Cells Expressing IL-10, PD-L1, and S100A12

Introduction: In diffuse large B-cell lymphoma (DLBCL), the number of circulating monocytes and neutrophils represents an independent prognostic factor. These cells include monocytic and granulocytic myeloid derived suppressor cells (M- and G-MDSCs) defined by their ability to suppress T-cell responses. MDSCs are a heterogeneous population described in inflammatory or infectious diseases as well as in numerous tumors including multiple myeloma, chronic lymphocytic leukemia and DLBCL. However, their mechanisms of action in DLBCL remain unclear. The aim of the study was to investigate the presence and mechanisms of suppression of MDSC subsets in DLBCL.Methods: Whole blood from 56 DLBCL at diagnosis and 45 healthy donors (HD) were analyzed by flow cytometry. Quantitative Real Time PCR were analyzed on Taqman@ array microfluidic cards. Cytokine levels in plasma and culture supernatants were measured by Luminex and Elisa. T-cell proliferation after monocyte depletion or treatment with inhibitors, was analyzed by CFSE assay.Results: By flow cytometry, we identified an expansion of G-MDSC (Linneg HLA-DRneg CD33pos CD11bpos) and M-MDSC (CD14pos HLA-DRlow) in DLBCL compared to HD (p<0.001). Interestingly, only M-MDSC number was correlated with the International Prognostic Index (IPI), the event-free survival (EFS), and the number of circulating Treg. Furthermore, T-cell proliferation was restored after monocyte depletion. To identify the mechanism of suppression involved, we evaluated the gene expression of key enzymes (ARG1, IDO1, NOS2, HO-1 and PTGS2) or immunomodulatory molecules (IL10, TGF β1, CD274/PD-L1, S100A8, S100A9, S100A12) involved in MDSC biology. ARG1, IDO1, IL10, CD274/PD-L1 and S100A12 were significantly up-regulated in DLBCL (p<0.05). At the protein level arginase 1, IL-10 and S100A12 were increased in DLBCL plasma, whereas PD-L1 expression on monocyte was increased in DLBCL compared to HD (p=0.03). Arginase 1 and IDO activities where increased in DLBCL patients. In DLBCL, IL-10 and S100A12 were detected in culture supernatants from stimulated PBMC and these molecules were decreased after CD14pos depletion (p<0.05). Finally, we defined 2 groups of DLBCL depending on M-MDSC content and analyzed the percentage of proliferating T cells after CD3/CD28 stimulation in the presence of various inhibitors or blocking antibodies (L-1MT, nor-NOHA, anti-IL-10, anti-PD-1 and anti-S100A12). In the group of patients with circulating MDSC, neutralizing IL-10, PDL-1 and S100A12 resulted in an increase of CD4 and/or CD8 T-cell proliferation.Conclusion: In summary, we identified MDSC subsets expanded in DLBCL as well as new mechanisms of immunosuppression in DLBCL. Myeloid-dependent T-cell suppression is attributed to a release of IL-10 and S100A12 and an increase of PD-L1 expression. DisclosuresCartron:Roche: Consultancy, Honoraria; GSK: Honoraria; Celgene: Honoraria; Sanofi: Honoraria; Gilead: Honoraria.

The expression of gingival epithelial junctions in response to subgingival biofilms

Periodontitis is an infectious inflammatory disease that destroys the tooth-supporting tissues. It is caused by the formation of subgingival biofilms on the surface of the tooth. Characteristic bacteria associated with subgingival biofilms are the Gram-negative anaerobes Porphyromonas gingivalis, Tannerella forsythia and Treponema denticola, collectively known as the “red complex” species. Inter-epithelial junctions ensure the barrier integrity of the gingival epithelium. This may however be disrupted by the biofilm challenge. The aim of this in vitro study was to investigate the effect of subgingival biofilms on the expression of inter-epithelial junctions by gingival epithelia, and evaluate the relative role of the red complex. Multi-layered human gingival epithelial cultures were challenged with a 10-species in vitro subgingival biofilm model, or its variant without the red complex, for 3 h and 24 h. A low-density array microfluidic card platform was then used for analyzing the expression of 62 genes encoding for tight junctions, gap junctions, adherens junctions, and desmosomes. Although there was a limited effect of the biofilms on the expression of tight, adherens and gap junctions, the expression of a number of desmosomal components was affected. In particular, Desmoglein-1 displayed a limited and transient up-regulation in response to the biofilm. In contrast, Desmocollin-2, Desmoplakin and Plakoglobin were down-regulated equally by both biofilm variants, after 24 h. In conclusion, this subgingival biofilm model may down-regulate selected desmosomal junctions in the gingival epithelium, irrespective of the presence of the “red complex.” In turn, this could compromise the structural integrity of the gingival tissue, favoring bacterial invasion and chronic infection.

Thrombospondin-1, -2 and -5 have differential effects on vascular smooth muscle cell physiology

IntroductionThe thrombospondins (TSPs) are matricellular proteins that exert multifunctional effects by binding cytokines, cell-surface receptors and other proteins. TSPs play important roles in vascular pathobiology and are all expressed in arterial lesions. The differential effects of TSP-1, -2, and -5 represent a gap in knowledge in vascular smooth muscle cell (VSMC) physiology. Our objective is to determine if structural differences of the TSPs imparted different effects on VSMC functions critical to the formation of neointimal hyperplasia. We hypothesize that TSP-1 and -2 induce similar patterns of migration, proliferation and gene expression, while the effects of TSP-5 are different. MethodsHuman aortic VSMC chemotaxis was tested for TSP-2 and TSP-5 (1–40 μg/mL), and compared to TSP-1 and serum-free media (SFM) using a modified Boyden chamber. Next, VSMCs were exposed to TSP-1, TSP-2 or TSP-5 (0.2–40 μg/mL). Proliferation was assessed by MTS assay. Finally, VSMCs were exposed to TSP-1, TSP-2, TSP-5 or SFM for 3, 6 or 24 h. Quantitative real-time PCR was performed on 96 genes using a microfluidic card. Statistical analysis was performed by ANOVA or t-test, with p < 0.05 being significant. ResultsTSP-1, TSP-2 and TSP-5 at 20 μg/mL all induce chemotaxis 3.1 fold compared to serum-free media. TSP-1 and TSP-2 induced proliferation 53% and 54% respectively, whereas TSP-5 did not. In the gene analysis, overall, cardiovascular system development and function is the canonical pathway most influenced by TSP treatment, and includes multiple growth factors, cytokines and proteases implicated in cellular migration, proliferation, vasculogenesis, apoptosis and inflammation pathways. Conclusions and relevanceThe results of this study indicate TSP-1, -2, and -5 play active roles in VSMC physiology and gene expression. Similarly to TSP-1, VSMC chemotaxis to TSP-2 and -5 is dose-dependent. TSP-1 and -2 induces VSMC proliferation, but TSP-5 does not, likely due conservation of N-terminal domains in TSP-1 and -2. In addition, TSP-1, -2 and -5 significantly affect VSMC gene expression; however, little overlap exists in the specific genes altered. This study further delineates TSP-1, -2 and -5's contributions to processes related to VSMC physiology.

Impact of genetic polymorphisms on paediatric atopic dermatitis.

In order to investigate whether polymorphisms of genes encoding some factors of innate and adaptive immunity play a role in the development of, or protection against atopic dermatitis (AD) and condition its severity, we genotyped 33 candidate genes and 47 single nucleotide polymorphisms (SNPs) using Custom TaqMan Array Microfluidic Cards and an ABI 7900HT analyser (Applied Biosystems, Foster City, CA, USA). The study involved 104 children with AD (29 with mild-to-moderate and 75 with severe disease; 42 girls; mean age ± SD, 5.8 ± 3.3 years) and 119 healthy controls (49 girls; mean age, 4.8 ± 3.0 years). IL10-rs1800872T, TG and MBL2-rs500737AG were all significantly more frequent among the children with AD (P = 0.015, P = 0.004 and P = 0.030), whereas IL10-rs1800896C and TC were more frequent in those without AD (P = 0.028 and P = 0.032). The VEGFA-rs2146326A and CTLA4-rs3087243AG SNPs were significantly more frequent in the children with mild/moderate AD than in those with severe AD (P = 0.048 andP = 0.036). IL10-rs1800872T and TG were significantly more frequent in the children with AD and other allergic diseases than in the controls (P = 0.014 and P = 0.007), whereas IL10-rs1800896TC and C were more frequent in the controls than in the children with AD and other allergic diseases (P = 0.0055 and P = 0.0034). These findings show that some of the polymorphisms involved in the immune response are also involved in some aspects of the development and course of AD and, although not conclusive, support the immunological hypothesis of the origin of the inflammatory lesions.

Gene expression in conjunctival melanoma cell lines treated with the histone deacetylase (HDAC) inhibitor valproic acid (VPA)

AbstractPurpose To investigate the differential regulation of genes in conjunctival melanoma cell lines (CRMM1 and CM2005.1) treated with valproic acid (VPA), a class I and II histone deacetylase (HDAC) inhibitor.Methods Based on previous viability assays, cell lines were treated with VPA (CRMM1: 3mM, CM2005.1: 5mM). At 24 and 72 h post‐treatment, RNA was extracted and processed for RT‐PCR using defined gene‐array microfluidic cards. Gene functions chosen for investigation related to HDACs, cell cycle (cyclins e.g. CCND2, CCNA1) cell death (caspases), melanocyte function (PAX6), increased susceptibility to malignant transformation (BAP1, GNAQ) and DNA damage (GADD45A).Results Upregulation of HDACs 1,2,3,4 6, SIRT2 and GADD45A occurred in CRMM1 cells by 24h but only after 24h for CM2005.1. Both CRMM1 and CM2005.1 showed increased CCND2 after VPA treatment, albeit higher in CM2005.1 (&gt;700‐fold by 72h, compared to 22‐fold in CRMM1). CCNA1 was increased at 24 and 72 h in CRMM1 (&gt;200 fold 24h). For CM2005.1 cells, CCNA1 was initially downregulated and upregulated by 72h (~30‐fold).Conclusion The delayed increase in GADD45A (DNA damage gene) in CM2005.1 cells compared with CRMM1 cells, is consistent with our toxicity assays showing CRMM1 more responsive to VPA than CM2005.1. The differences of CCND2 and CCNA1 fold‐changes (which are partially regulated by HDACs) between the two cell lines, may explain their dissimilar responses to VPA. Funding – NFMRI

Multiparametric diagnostics of cardiomyopathies by microRNA signatures

The diagnosis of cardiomyopathies by endomyocardial biopsy analysis is the gold standard for confirmation of causative reasons but is failing if a sample does not contain the area of interest due to focal pathology. Biopsies are revealing an extract of the current situation of the heart muscle only, and the need for global organ-specific or systemic markers is obvious in order to minimize sampling errors. Global markers like specific gene expression signatures in myocardial tissue may therefore reflect the focal situation or condition of the whole myocardium. Besides gene expression profiles, microRNAs (miRNAs) represent a new group of stable biomarkers that are detectable both in tissue and body fluids. Such miRNAs may serve as cardiological biomarkers to characterize inflammatory processes, to confirm viral infections, and to differentiate various forms of infection. The predictive power of single miRNAs for diagnosis of complex diseases may be further increased if several distinctly deregulated candidates are combined to form a specific miRNA signature. Diagnostic systems that generate disease-related miRNA profiles are based on microarrays, bead-based oligo sorbent assays, or on assays based on real-time polymerase chain reactions and placed on microfluidic cards or nanowell plates. Multiparametric diagnostic systems that can measure differentially expressed miRNAs may become the diagnostic tool of the future due to their predictive value with respect to clinical course, therapeutic decisions, and therapy monitoring. We discuss here specific merits, limitations and the potential of currently available analytical platforms for diagnostics of heart muscle diseases based on miRNA profiling. Contains 34 references.

Expression patterning reveals retinal inflammation as a minor factor in experimental retinopathy of ZDF rats

Obese Zucker diabetic fatty (ZDF) rats are used as a type-2 diabetes model for microvascular complications. In order to study retinopathy in this model, changes in retinal vasculature were analyzed by quantitative morphometry and related to retinal expression of 46 selected genes that were analyzed by microfluidic card PCR technology. At 3 months of age, obese animals had developed stable hyperglycemia (20.7 ± 1.3 mmol/L plasma glucose vs. 6.5 ± 0.1 mmol/L in lean). Hyperinsulinemia initially presented in obese rats at 2 months (10.5 ± 0.7 μg/L plasma insulin vs. 0.2 ± 0.04 μg/L in lean) and decreased at 3 months (3.9 ± 0.6 vs. 0.5 ± 0.09 μg/ml in lean). At 8 months of age, animals had developed microvascular complications. An increased number of acellular capillaries in obese (24 ± 5/mm2) versus lean (15 ± 4/mm2) and a decreased number of retinal pericytes in obese (2,270 ± 250/mm2) versus lean animals (1,620 ± 243/mm2) could be observed. VEGFa, MIF, and HIF-1α were the most abundantly expressed and inflammatory genes such as TNFα and IL-6 are the least abundantly expressed genes. None of these genes were differentially regulated. Surprisingly, specific growth factors such as bFGF (FGF2) and placental growth factor, and adhesion molecules such as ICAM-1 were abundantly expressed and up-regulated in diabetic versus non-diabetic ZDF rats. In summary, we observed in type-2 diabetic ZDF rats retinopathy with retinal vasoregression along with a simultaneous up-regulation of specific growth factors such as bFGF and adhesion molecules, but only minor changes in key inflammatory genes.Electronic supplementary materialThe online version of this article (doi:10.1007/s00592-013-0550-2) contains supplementary material, which is available to authorized users.

Measuring microRNA expression in mouse hematopoietic stem cells.

MicroRNAs (miRNAs) are important regulators of diverse biologic processes. In the hematopoietic system, miRNAs have been shown to regulate lineage fate decisions, mature immune effector cell function, apoptosis, and cell cycling, and a more limited number of miRNAs has been shown to regulate hematopoietic stem cell (HSC) self-renewal. Many of these miRNAs were initially identified as candidate regulators of HSC function by comparing miRNA expression in hematopoietic stem and progenitors cells (HSPCs) to their mature progeny. While the measurement of miRNA expression in rare cell populations such as HSCs poses practical challenges due to the low amount of RNA present, a number of techniques have been developed to measure miRNAs in small numbers of cells. Here, we describe our protocol for measuring miRNAs in purified mouse HSCs using a highly sensitive real-time quantitative PCR strategy that utilizes microfluidic array cards containing pre-spotted TaqMan probes that allows the detection of mature miRNAs in small reaction volumes. We also describe a simple data analysis method to evaluate miRNA expression profiling data using an open-source software package (HTqPCR) using mouse HSC miRNA profiling data generated in our lab.

Bone Marrow Mesenchymal Stem Cell (BM-MSC) Release Microvesicles/Exosomes That Incorporate Into Hematopoietic Cells From MDS Patients and May Modify Their Behaviour

A new mechanism of intercellular communication has been proposed consisting in the secretion of exosomes/ microvesicles (MVs). Such mechanism has been shown to modify the functional properties of recipient cells by the transfer of proteins, mRNA, or micro-RNAs. The hypothesis of the present work was that MSC from MDS patients could differentially modify the HPC properties throughout the shedding of MVs when compared with those from controls due to their different content. Material and methods: MVs were isolated from MSC from bone marrow (BM) samples 18 patients diagnosed with ‘de novo' and untreated low risk MDS and from MSC from 12 healthy BM. BM-MSC at third passage were cultured in DMEM deprived of FCS, and supernatants were collected after 6 or 24 hours. MVs purification was performed in the majority of the experiments (16 MDS/ 9 Controls) using the ExoQuick-TC exosome precipitation solution (ExoQuick; System Biosiences). To confirm the isolation of MVs by exosome precipitation solution, in some cases (2 MDS/3 Controls) the MVs were obtained by ultracentrifugation; MVs identification was done by transmission electron microscopy (TEM) as well as by flow cytometry (FC). To evaluate if the micro-RNA content into MSC-MVs from patients and controls was different, expression analysis of miRNAs was done using Megaplex™ RT Primers pool (Applied Biosystems) and 384-well microfluidic cards (TaqMan® MicroRNA Array A) were loaded with retro-transcription product and PCR runs were performed on a 7900HT Fast Real-time PCR system (eight MVs from MDS and 4 from HD).To demonstrate the incorporation of MVs from MSC into human hematopoietic progenitors (HPC: CD34+ cells obtained by immunomagnetic selection) HPC were co-cultured with MVs from MSC. Incorporation of Vybrant Dil-labelled MVs into HPC was evaluated at 1, 3, 6, and 24 h. by FC. To detect the incorporation of MVs by confocal microscopy (CM) an intracellular primary Ab for CD90 (Santa Cruz, Biotechnology) was used as MVs marker and anti-CD45 to detect HPC. A Zeiss LSM 510 CM connected to a digital camera (Leica DC 100) were used to obtain confocal images. Apoptotic rate of CD34+ cells that had the MVs-MSC from MDS and controls were evaluated by FC by using APC H7 Annexin V DY634 (Immunostep) and 7AAD (BD Biosciences). Results: More than 95% of MVs isolated by ExoKit system from supernatants of cultured MSC from 6 HD and 6 MDS patients showed scatter intensities lower than of 6µm beads. We observed, in all cases, the same FC pattern. Also, MVs/exosomes isolated by ultracentrifugation (3 MDS/ 5 HD) showed the same FC pattern. MVs from MDS and controls isolated by ultracentrifugation were identified by TEM (fig1). When co-cultures of CD34+ HPC and MVs were studied in both HD and MDS, MVs were incorporated into HPC in all cases (fig2). When the content of miRNAS in the MVs from MDS and HD were compared significant differences were observed between both groups. Twenty-one out of 384 evaluated miRNAs were over-expressed in the MVs from patients compared with the controls. To confirm these results, the expression of miR10a and miR-132 was analyzed by RT-PCR. In both cases their expression was significantly increased in MVs from patients. Recently, it has been suggested that the cargo of these structures are bioactive molecules, therefore we explored the possibility that MVs could modify the behavior of the target cell. For this purpose we searched in which pathways the overexpressed miRNAs could be involved and apoptosis was among them. Since it is considered a very important process in MDS pathophysiology we compared apoptosis by FC, after co-culturing CD34+ cells with MVs from MSC of MDS and HD. Interestingly, preliminary results show that the MVs from MDS protected better from apoptosis CD34+ cells than MVs obtained from controls. In summary, in the present study we show that BM-MSC produce MVs/exosomes with different microRNAs content according to their origin, MDS or HD. These structures can be incorporated into HPC and can modify their properties.Funding: Instituto de Salud Carlos III. PI12/01775. Junta de Castilla y León.GRS 873/A/13. Portuguese FST Grant. SFRH/BD/86451/2012 Disclosures:Diez-Campelo:Celgene: Honoraria, Research Funding; Novartis: Honoraria, Research Funding. San Miguel:Jansen, Celgene, Onyx, Novartis, Millenium: Membership on an entity's Board of Directors or advisory committees. del Cañizo:Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Jansen-Cilag: Membership on an entity's Board of Directors or advisory committees, Research Funding; Arry: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding. [Display omitted] [Display omitted]

Abstract A56: Identification of a micro RNA profile to predict response to therapy and improve patient survival in ovarian cancer

Abstract Introduction &amp; Objectives: Ovarian cancer (OC) is the leading cause of death among gynecological malignancies in developed countries. The standard treatment is surgery plus platinum-paclitaxel (CP/TX) chemotherapy. Nevertheless, 70% of these patients are diagnosed in advanced stages, and, among those, 75% will recur, become resistant to therapies and die. We believe that an improvement in OC survival might be related with an early identification of those patients, since long survival (SV) is related to chemosensitivity. Our aim is to identify an expression profile of micro RNAs (miRNAs) associated with SV of patients with advanced OC. Material &amp; Methods: Formalin-fixed paraffin-embedded (FFPE) primary tumor tissues from late stage (III/IV) OC patients were collected at the time of surgery for the study. All patients were treated with optimal surgery and standard chemotherapy (CP/TX; after surgery). Samples were divided into two groups; (a) patients with “long SV” (SV&amp;gt;10 years after diagnosis) and (b) patients with “short SV”. The identification of miRNAs associated with each profile of SV was performed using TaqMan Array MicroRNA microfluidic cards in 30 patients. Results: The identification phase has shown that the majority of the miRNAs appeared to be down-regulated in the group of “short SV” versus the “long SV”. A validation phase in a new group of tumor tissue samples is ready to validate the promising miRNA candidates that seem to be associated with the resistant (short SV) and the sensitive (long SV) profiles. Conclusions: The ability to identify markers associated with “long SV” in patients with advanced OC could allow transforming the impact of the disease through the reduction of chemotherapy treatments and the reduction of unnecessary health care costs. Moreover, it could permit the generation of knowledge applicable to the future development of new therapies for the “short SV” since they are supposed to be resistant to the therapy. Citation Format: Marina Rigau, Blanca Majem, Tatiana Altadill, Lucia Lanau, José-Luis Sánchez-Iglesias, Josep Castellví, Assumpció Pérez-Benavente, Silvia Cabrera, Angel García, Jordi Xercavins, Francesc Alameda, Xavier Matias-Guiu, Antonio Gil-Moreno, Josep-Maria Del Campo, Marta Llauradó, Jaume Reventós. Identification of a micro RNA profile to predict response to therapy and improve patient survival in ovarian cancer. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research: From Concept to Clinic; Sep 18-21, 2013; Miami, FL. Philadelphia (PA): AACR; Clin Cancer Res 2013;19(19 Suppl):Abstract nr A56.

Renal Heparan Sulfate Proteoglycans Modulate Fibroblast Growth Factor 2 Signaling in Experimental Chronic Transplant Dysfunction

Depending on the glycan structure, proteoglycans can act as coreceptors for growth factors. We hypothesized that proteoglycans and their growth factor ligands orchestrate tissue remodeling in chronic transplant dysfunction. We have previously shown perlecan to be selectively up-regulated in the glomeruli and arteries in a rat renal transplantation model. Using the same model, here we present quantitative RT-PCR profiling data on proteoglycans and growth factors from laser-microdissected glomeruli, arterial tunicae mediae, and neointimae at 12 weeks after transplantation. In glomeruli and neointimae of allografts, selective induction of the matrix heparan sulfate proteoglycan perlecan was observed, along with massive accumulation of fibroblast growth factor 2 (FGF2). Profiling the heparan sulfate polysaccharide side chains revealed conversion from a non-FGF2-binding heparan sulfate phenotype in control and isografted kidneys toward a FGF2-binding phenotype in allografts. In vitro experiments with perlecan-positive rat mesangial cells showed that FGF2-induced proliferation is dependent on sulfation and can be inhibited by exogenously added heparan sulfate. These findings indicate that matrix proteoglycans such as perlecan serve as functional docking platforms for FGF2 in chronic transplant dysfunction. We speculate that heparin-like glycomimetics could be a promising intervention to retard development of glomerulosclerosis and neointima formation in chronic transplant dysfunction.

Impact of bone marrow stromal cells on Bcl-2 family members in chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) is the most common form of adult leukemia in the Western world. High levels of Bcl-2 family anti-apoptotic proteins are responsible for apoptosis resistance. Besides anti-apoptotic proteins, the microenvironment provides substantial survival signals to CLL leukemic cells. However, in-depth knowledge on the role of individual Bcl-2 family members in the context of the microenvironment is still limited. We performed a comprehensive analysis of transcripts and proteins of 18 Bcl-2 family members using an “apoptosis array microfluidic card” in primary cells before and after stromal co-cultures. Our data showed that five of six anti-apoptotic members (excluding Bcl-b), two of three pro-apoptotic members (excluding Bok) and six of nine BH3-only members were present at detectable mRNA levels in CLL cells. Importantly, stromal-mediated extended survival of CLL cells was strongly associated with elevated global transcription. Upon co-culturing with stromal cells, there was an early response of an increase in anti- (2/5) and pro-apoptotic protein (3/8) transcripts on day 1, while an increase in anti-apoptotic proteins was observed on day 3, with no significant change in pro-apoptotic proteins. Our study revealed a differential pattern of expression of both transcripts and proteins following stromal co-cultures, proposing a significance of Bcl-2 family members in the stromal microenvironment.