568 research outputs found

    TIMP3 interplays with apelin to regulate cardiovascular metabolism in hypercholesterolemic mice

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    Tissue inhibitor of metalloproteinase 3 (TIMP3) is an extracellular matrix (ECM) bound protein, which has been shown to be downregulated in human subjects and experimental models with cardiometabolic disorders, including type 2 diabetes mellitus, hypertension and atherosclerosis. The aim of this study was to investigate the effects of TIMP3 on cardiac energy homeostasis during increased metabolic stress conditions

    Evaluation of tolerance to lentiviral LV-RPE65 gene therapy vector after subretinal delivery in non-human primates.

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    Several approaches have been developed for gene therapy in RPE65-related Leber congenital amaurosis. To date, strategies that have reached the clinical stages rely on adeno-associated viral vectors and two of them documented limited long-term effect. We have developed a lentiviral-based strategy of RPE65 gene transfer that efficiently restored protein expression and cone function in RPE65-deficient mice. In this study, we evaluated the ocular and systemic tolerances of this lentiviral-based therapy (LV-RPE65) on healthy nonhuman primates (NHPs), without adjuvant systemic anti-inflammatory prophylaxis. For the first time, we describe the early kinetics of retinal detachment at 2, 4, and 7 days after subretinal injection using multimodal imaging in 5 NHPs. We revealed prolonged reattachment times in LV-RPE65-injected eyes compared to vehicle-injected eyes. Low- (n = 2) and high-dose (n = 2) LV-RPE65-injected eyes presented a reduction of the outer nuclear and photoreceptor outer segment layer thickness in the macula, that was more pronounced than in vehicle-injected eyes (n = 4). All LV-RPE65-injected eyes showed an initial perivascular reaction that resolved spontaneously within 14 days. Despite foveal structural changes, full-field electroretinography indicated that the overall retinal function was preserved over time and immunohistochemistry identified no difference in glial, microglial, or leucocyte ocular activation between low-dose, high-dose, and vehicle-injected eyes. Moreover, LV-RPE65-injected animals did not show signs of vector shedding or extraocular targeting, confirming the safe ocular restriction of the vector. Our results evidence a limited ocular tolerance to LV-RPE65 after subretinal injection without adjuvant anti-inflammatory prophylaxis, with complications linked to this route of administration necessitating to block this transient inflammatory event

    Full-length soluble urokinase plasminogen activator receptor down-modulates nephrin expression in podocytes

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    Increased plasma level of soluble urokinase-type plasminogen activator receptor (suPAR) was associated recently with focal segmental glomerulosclerosis (FSGS). In addition, different clinical studies observed increased concentration of suPAR in various glomerular diseases and in other human pathologies with nephrotic syndromes such as HIV and Hantavirus infection, diabetes and cardiovascular disorders. Here, we show that suPAR induces nephrin down-modulation in human podocytes. This phenomenon is mediated only by full-length suPAR, is time-and dose-dependent and is associated with the suppression of Wilms' tumor 1 (WT-1) transcription factor expression. Moreover, an antagonist of alpha v beta 3 integrin RGDfv blocked suPAR-induced suppression of nephrin. These in vitro data were confirmed in an in vivo uPAR knock out Plaur(-/-) mice model by demonstrating that the infusion of suPAR inhibits expression of nephrin and WT-1 in podocytes and induces proteinuria. This study unveiled that interaction of full-length suPAR with alpha v beta 3 integrin expressed on podocytes results in down-modulation of nephrin that may affect kidney functionality in different human pathologies characterized by increased concentration of suPAR

    Full-length soluble urokinase plasminogen activator receptor down-modulates nephrin expression in podocytes

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    Increased plasma level of soluble urokinase-type plasminogen activator receptor (suPAR) was associated recently with focal segmental glomerulosclerosis (FSGS). In addition, different clinical studies observed increased concentration of suPAR in various glomerular diseases and in other human pathologies with nephrotic syndromes such as HIV and Hantavirus infection, diabetes and cardiovascular disorders. Here, we show that suPAR induces nephrin down-modulation in human podocytes. This phenomenon is mediated only by full-length suPAR, is time-and dose-dependent and is associated with the suppression of Wilms' tumor 1 (WT-1) transcription factor expression. Moreover, an antagonist of alpha v beta 3 integrin RGDfv blocked suPAR-induced suppression of nephrin. These in vitro data were confirmed in an in vivo uPAR knock out Plaur(-/-) mice model by demonstrating that the infusion of suPAR inhibits expression of nephrin and WT-1 in podocytes and induces proteinuria. This study unveiled that interaction of full-length suPAR with alpha v beta 3 integrin expressed on podocytes results in down-modulation of nephrin that may affect kidney functionality in different human pathologies characterized by increased concentration of suPAR

    Tumour-derived PGD2 and NKp30-B7H6 engagement drives an immunosuppressive ILC2-MDSC axis.

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    Group 2 innate lymphoid cells (ILC2s) are involved in human diseases, such as allergy, atopic dermatitis and nasal polyposis, but their function in human cancer remains unclear. Here we show that, in acute promyelocytic leukaemia (APL), ILC2s are increased and hyper-activated through the interaction of CRTH2 and NKp30 with elevated tumour-derived PGD2 and B7H6, respectively. ILC2s, in turn, activate monocytic myeloid-derived suppressor cells (M-MDSCs) via IL-13 secretion. Upon treating APL with all-trans retinoic acid and achieving complete remission, the levels of PGD2, NKp30, ILC2s, IL-13 and M-MDSCs are restored. Similarly, disruption of this tumour immunosuppressive axis by specifically blocking PGD2, IL-13 and NKp30 partially restores ILC2 and M-MDSC levels and results in increased survival. Thus, using APL as a model, we uncover a tolerogenic pathway that may represent a relevant immunosuppressive, therapeutic targetable, mechanism operating in various human tumour types, as supported by our observations in prostate cancer.Group 2 innate lymphoid cells (ILC2s) modulate inflammatory and allergic responses, but their function in cancer immunity is still unclear. Here the authors show that, in acute promyelocytic leukaemia, tumour-activated ILC2s secrete IL-13 to induce myeloid-derived suppressor cells and support tumour growth

    Identification, isolation and in vitro expansion of human and nonhuman primate T stem cell memory cell

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    The T cell compartment is phenotypically and functionally heterogeneous; subsets of naive and memory cells have different functional properties, and also differ with respect to homeostatic potential and the ability to persist in vivo. Human stem cell memory T (TSCM) cells, which possess superior immune reconstitution and antitumor response capabilities, can be identified by polychromatic flow cytometry on the basis of the simultaneous expression of several naive markers together with the memory marker CD95. We describe here a protocol based on the minimum set of markers required for optimal identification of human and nonhuman primate (NHP) TSCM cells with commonly available flow cytometers. By using flow sorters, TSCM cells can thereby be isolated efficiently at high yield and purity. With the use of the 5.5-h isolation procedure, depending on the number of cells needed, the sorting procedure can last for 2-15 h. We also indicate multiple strategies for their efficient expansion in vitro at consistent numbers for functional characterization or adoptive transfer experiments

    Effect of deprescribing in elderly patients with type 2 diabetes: iDegLira might improve quality of life

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    Older people with type 2 diabetes (T2D) often have several comorbidities and take multiple drugs. This study tested a deprescribing strategy in older T2D patients, replacing a hypoglycemic therapeutic scheme with a single drug combination (iDegLira). In this 6-month, real-world, single-arm, open interventional study, we enrolled patients >= 75 years with T2D taking >= 2 medications for diabetes. Patients on a basal-bolus insulin regimen (n = 13), on a basal-insulin regimen plus oral glucose-lowering drugs (n = 9), and those on oral glucose-lowering drugs (n = 18) were switched to daily iDegLira. The primary clinical endpoint of the study was an improvement in CASP-19 and/or DTSQ score after 6 months. We also evaluated changes in glucose metabolism, depression, cognitive function, level of independence, and markers of inflammation. Thirty-five patients (12 women, mean age=81.4 y) completed the protocol. Results shown here are given as estimated mean difference (95%CI). DTSQ score improved [11.08 (7.13/15.02); p = 0.0001], whereas CASP-19 did not after 6 months of iDegLira treatment. We observed reductions in BMI [- 0.81 (- 1.27/0.35); p < 0.001], fasting glucose [- 52.07 (- 77.26/26.88); p < 0.001], HbA1c [- 0.58 (- 1.08/0.08); p < 0.05], and TNF-alpha [- 1.83 (- 3.12/- 0.54); p = 0.007]. Activities of daily living and cognitive function score increased [p = 0.006 and p = 0.02], whereas depression score significantly decreased [p = 0.02]. Notably, no patient reported episodes of severe hypoglycemia after initiation of iDegLira treatment. Among older patients with T2D, deprescribing using a single dose of iDegLira resulted in a greater likelihood of improving health and quality of life. Although our data indicate the effectiveness and safety of this approach, it must be confirmed in larger studies

    Design and Characterization of a Human Monoclonal Antibody that Modulates Mutant Connexin 26 Hemichannels Implicated in Deafness and Skin Disorders

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    Background: Mutations leading to changes in properties, regulation, or expression of connexin-made channels have been implicated in 28 distinct human hereditary diseases. Eight of these result from variants of connexin 26 (Cx26), a protein critically involved in cell-cell signaling in the inner ear and skin. Lack of non-toxic drugs with defined mechanisms of action poses a serious obstacle to therapeutic interventions for diseases caused by mutant connexins. In particular, molecules that specifically modulate connexin hemichannel function without affecting gap junction channels are considered of primary importance for the study of connexin hemichannel role in physiological as well as pathological conditions. Monoclonal antibodies developed in the last three decades have become the most important class of therapeutic biologicals. Recombinant methods permit rapid selection and improvement of monoclonal antibodies from libraries with large diversity.Methods: By screening a combinatorial library of human single-chain fragment variable (scFv) antibodies expressed in phage, we identified a candidate that binds an extracellular epitope of Cx26. We characterized antibody action using a variety of biochemical and biophysical assays in HeLa cells, organotypic cultures of mouse cochlea and human keratinocyte-derived cells.Results: We determined that the antibody is a remarkably efficient, non-toxic, and completely reversible inhibitor of hemichannels formed by connexin 26 and does not affect direct cell-cell communication via gap junction channels. Importantly, we also demonstrate that the antibody efficiently inhibits hyperative mutant Cx26 hemichannels implicated in autosomal dominant non-syndromic hearing impairment accompanied by keratitis and hystrix-like ichthyosis-deafness (KID/HID) syndrome. We solved the crystal structure of the antibody, identified residues that are critical for binding and used molecular dynamics to uncover its mechanism of action.Conclusions: Although further studies will be necessary to validate the effect of the antibody in vivo, the methodology described here can be extended to select antibodies against hemichannels composed by other connexin isoforms and, consequently, to target other pathologies associated with hyperactive hemichannels. Our study highlights the potential of this approach and identifies connexins as therapeutic targets addressable by screening phage display libraries expressing human randomized antibodies

    826. Transduction of Human Hematopoietic Stem Cells by RD114-TR-Pseudotyped Lentiviral Vectors

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    HIV-1-derived lentiviral vectors are efficiently pseudotyped by a chimeric envelope (RD114-TR) encoding the extracellular and transmembrane domains of the FLV RD114 glycoprotein fused to cytoplasmic tail (TR) of the MLV 4070A amphotropic glycoprotein. RD114-TR pseudotyped vectors may be concentrated by centrifugation, are resistant to complement inactivation, and are of particular interest for both ex vivo and in vivo gene therapy applications. We carried out a comparative analysis of VSV-G and RD114-TR-pseudotyped lentiviral vectors in transducing human cord blood-derived CD34+ hematopoietic stem/progenitor cells. Transduction efficiency was comparatively analysed in CD34+ cells in liquid culture, in the progeny of CD34+ clonogenic progenitors in semi-solid culture, and in the progeny of CD34+ repopulating stem cells after xeno-transplantation in NOD-SCID mice. In all cases, RD114-TR-pseudotyped vectors transduced hematopoietic cells at lower m.o.i., resulting in lower toxicity and more efficient stable transduction at comparable vector copy number per genome. Potential changes in CD34+ cells transcription profile and phenotype upon transduction with RD114-TR or VSV-G-pseudotyped vectors was investigated by Affymetrix Gene Chips microarray analysis. We found no significant difference in gene expression patterns between mock-RD114-TR and VSV-G-transduced cells. Our study show that the biology of repopulating hematopoietic stem cells and their progeny is not affected by transduction with RD114-TR-pseudotyped lentiviral vectors
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