scholarly journals Insulin inhibits inflammation-induced cone death in retinal detachment

2020 ◽  
Vol 17 (1) ◽  
Author(s):  
Jean-Baptiste Conart ◽  
Guillaume Blot ◽  
Sébastien Augustin ◽  
Géraldine Millet-Puel ◽  
Christophe Roubeix ◽  
...  
Keyword(s):  
Retinal Detachment ◽  
Inflammatory Response ◽  
Immune Cell ◽  
Visual Outcome ◽  
Inflammatory Cells ◽  
Cell Loss ◽  
Link Type ◽  
Insulin Sensitizers ◽  
Retinal Explants

Abstract Background Rhegmatogenous retinal detachment (RD) involving the macula is a major cause of visual impairment despite high surgical success rate, mainly because of cone death. RD causes the infiltration of activated immune cells, but it is not clear whether and how infiltrating inflammatory cells contribute to cone cell loss. Methods Vitreous samples from patients with RD and from control patients with macular hole were analyzed to characterize the inflammatory response to RD. A mouse model of RD and retinal explants culture were then used to explore the mechanisms leading to cone death. Results Analysis of vitreous samples confirms that RD induces a marked inflammatory response with increased cytokine and chemokine expression in humans, which is closely mimicked by experimental murine RD. In this model, we corroborate that myeloid cells and T-lymphocytes contribute to cone loss, as the inhibition of their accumulation by Thrombospondin 1 (TSP1) increased cone survival. Using monocyte/retinal co-cultures and TSP1 treatment in RD, we demonstrate that immune cell infiltration downregulates rod-derived cone viability factor (RdCVF), which physiologically regulates glucose uptake in cones. Insulin and the insulin sensitizers rosiglitazone and metformin prevent in part the RD-induced cone loss in vivo, despite the persistence of inflammation Conclusion Our results describe a new mechanism by which inflammation induces cone death in RD, likely through cone starvation due to the downregulation of RdCVF that could be reversed by insulin. Therapeutic inhibition of inflammation and stimulation of glucose availability in cones by insulin signaling might prevent RD-associated cone death until the RD can be surgically repaired and improve visual outcome after RD. Trial registration ClinicalTrials.govNCT03318588

scholarly journals Stimulation of Insulin Signaling Reverses Inflammation-Induced Cone Death in Retinal Detachment

2020 ◽  
Author(s):  
Jean-Baptiste CONART ◽  
Guillaume Blot ◽  
Sébastien Augustin ◽  
Christophe Roubeix ◽  
Fanny Beguier ◽  
...  
Keyword(s):  
Retinal Detachment ◽  
Inflammatory Response ◽  
Insulin Signaling ◽  
Visual Outcome ◽  
Age Related Macular Degeneration ◽  
Age Related ◽  
Retinal Explants ◽  
Stimulation Of

Abstract Background Rhegmatogenous retinal detachment (RD) involving the macula is a major cause of visual impairment despite high surgical success rate, mainly because of cone death. We and others have shown that cone loss occurs secondary to chronic inflammation in many retinal diseases, including age-related macular degeneration and retinitis pigmentosa. We here investigated the yet unknown mechanisms of inflammation-induced cone death in RD.Methods Vitreous samples from patients with RD and from control patients with macular hole were analyzed to characterize the inflammatory response to RD. A mouse model of RD and retinal explants culture were then used to explore the mechanisms leading to cone death.Results Analysis of vitreous samples shows that RD induces a marked inflammatory response with increased cytokine and chemokine expression in humans, which is closely mimicked by experimental murine RD. In this model, we demonstrate that myeloid cells and T-lymphocytes directly contribute to cone loss, as the inhibition of their accumulation by Thrombospondin 1 increased cone survival. We show that cones are highly dependent on glucose and insulin signaling for survival in vitro and that insulin, and the insulin sensitizers rosiglitazone and metformin, prevent RD-induced cone loss in vivo, despite the persistence of inflammation.Conclusion Our results describe a new mechanism by which inflammation, likely through a combination of competition for glucose and the inhibition of insulin signaling, promotes cone death in RD. Therapeutic inhibition of inflammation and stimulation of insulin signaling might prevent RD-associated cone death until the RD can be surgically repaired and improve visual outcome after RD.Trial registration: ClinicalTrials.gov Identifier NCT03318588

scholarly journals Deregulated immune cell recruitment orchestrated by FOXM1 impairs human diabetic wound healing

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Andrew P. Sawaya ◽  
Rivka C. Stone ◽  
Stephen R. Brooks ◽  
Irena Pastar ◽  
Ivan Jozic ◽  
...  
Keyword(s):  
Wound Healing ◽  
Inflammatory Response ◽  
Molecular Mechanisms ◽  
Immune Cell ◽  
Diabetic Mouse ◽  
Transcriptional Networks ◽  
Life Threatening ◽  
Diabetic Wound Healing ◽  
Diabetic Wounds

Abstract Diabetic foot ulcers (DFUs) are a life-threatening disease that often result in lower limb amputations and a shortened lifespan. However, molecular mechanisms contributing to the pathogenesis of DFUs remain poorly understood. We use next-generation sequencing to generate a human dataset of pathogenic DFUs to compare to transcriptional profiles of human skin and oral acute wounds, oral as a model of “ideal” adult tissue repair due to accelerated closure without scarring. Here we identify major transcriptional networks deregulated in DFUs that result in decreased neutrophils and macrophages recruitment and overall poorly controlled inflammatory response. Transcription factors FOXM1 and STAT3, which function to activate and promote survival of immune cells, are inhibited in DFUs. Moreover, inhibition of FOXM1 in diabetic mouse models (STZ-induced and db/db) results in delayed wound healing and decreased neutrophil and macrophage recruitment in diabetic wounds in vivo. Our data underscore the role of a perturbed, ineffective inflammatory response as a major contributor to the pathogenesis of DFUs, which is facilitated by FOXM1-mediated deregulation of recruitment of neutrophils and macrophages, revealing a potential therapeutic strategy.

scholarly journals GPRC5b Modulates Inflammatory Response in Glomerular Diseases via NF-κB Pathway

2019 ◽  
Vol 30 (9) ◽  
pp. 1573-1586 ◽  
Author(s):  
Sonia Zambrano ◽  
Katja Möller-Hackbarth ◽  
Xidan Li ◽  
Patricia Q. Rodriguez ◽  
Emmanuelle Charrin ◽  
...  
Keyword(s):  
Inflammatory Response ◽  
Knockout Mice ◽  
Large Scale ◽  
Molecular Mechanisms ◽  
Inflammatory Cells ◽  
Data Sets ◽  
Glomerular Diseases ◽  
Filtration Barrier ◽  
Inflammatory Processes

BackgroundInflammatory processes play an important role in the pathogenesis of glomerulopathies. Finding novel ways to suppress glomerular inflammation may offer a new way to stop disease progression. However, the molecular mechanisms that initiate and drive inflammation in the glomerulus are still poorly understood.MethodsWe performed large-scale gene expression profiling of glomerulus-associated G protein–coupled receptors (GPCRs) to identify new potential therapeutic targets for glomerulopathies. The expression of Gprc5b in disease was analyzed using quantitative PCR and immunofluorescence, and by analyzing published microarray data sets. In vivo studies were carried out in a podocyte-specific Gprc5b knockout mouse line. Mechanistic studies were performed in cultured human podocytes.ResultsWe identified an orphan GPCR, Gprc5b, as a novel gene highly enriched in podocytes that was significantly upregulated in common human glomerulopathies, including diabetic nephropathy, IgA nephropathy, and lupus nephritis. Similar upregulation of Gprc5b was detected in LPS-induced nephropathy in mice. Studies in podocyte-specific Gprc5b knockout mice showed that Gprc5b was not essential for normal development of the glomerular filtration barrier. However, knockout mice were partially protected from LPS-induced proteinuria and recruitment of inflammatory cells. Mechanistically, RNA sequencing in Gprc5b knockouts mice and experiments in cultured human podocytes showed that Gpr5cb regulated inflammatory response in podocytes via NF-κB signaling.ConclusionsGPRC5b is a novel podocyte-specific receptor that regulates inflammatory response in the glomerulus by modulating the NF-κB signaling pathway. Upregulation of Gprc5b in human glomerulopathies suggests that it may play a role in their pathogenesis.

scholarly journals Intrinsic Abnormalities of Cystic Fibrosis Airway Connective Tissue Revealed by an In Vitro 3D Stromal Model

Cells ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 1371
Author(s):  
Claudia Mazio ◽  
Laura S. Scognamiglio ◽  
Rossella De Cegli ◽  
Luis J. V. Galietta ◽  
Diego Di Bernardo ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Inflammatory Response ◽  
Bacterial Infections ◽  
Inflammatory Cells ◽  
Lung Model ◽  
Lung Dysfunction ◽  
Novel Therapeutic Strategies ◽  
And Function

Cystic fibrosis is characterized by lung dysfunction involving mucus hypersecretion, bacterial infections, and inflammatory response. Inflammation triggers pro-fibrotic signals that compromise lung structure and function. At present, several in vitro cystic fibrosis models have been developed to study epithelial dysfunction but none of these focuses on stromal alterations. Here we show a new cystic fibrosis 3D stromal lung model made up of primary fibroblasts embedded in their own extracellular matrix and investigate its morphological and transcriptomic features. Cystic fibrosis fibroblasts showed a high proliferation rate and produced an abundant and chaotic matrix with increased protein content and elastic modulus. More interesting, they had enhanced pro-fibrotic markers and genes involved in epithelial function and inflammatory response. In conclusion, our study reveals that cystic fibrosis fibroblasts maintain in vitro an activated pro-fibrotic state. This abnormality may play in vivo a role in the modulation of epithelial and inflammatory cell behavior and lung remodeling. We argue that the proposed bioengineered model may provide new insights on epithelial/stromal/inflammatory cells crosstalk in cystic fibrosis, paving the way for novel therapeutic strategies.

scholarly journals Heparan Sulfate Structure Affects Autophagy, Lifespan, Responses to Oxidative Stress, and Cell Degeneration in Drosophila parkin Mutants

2019 ◽  
Vol 10 (1) ◽  
pp. 129-141 ◽  
Author(s):  
Claire Reynolds-Peterson ◽  
Jie Xu ◽  
Na Zhao ◽  
Casey Cruse ◽  
Brandon Yonel ◽  
...  
Keyword(s):  
Heparan Sulfate ◽  
Flight Muscle ◽  
Cell Loss ◽  
Building Blocks ◽  
Cell Types ◽  
Cell Degeneration ◽  
Link Type ◽  
Molecular Building Blocks ◽  
Modified Proteins

Autophagy is a catabolic process that provides cells with energy and molecular building blocks during nutritional stress. Autophagy also removes misfolded proteins and damaged organelles, a critical mechanism for cellular repair. Earlier work demonstrated that heparan sulfate proteoglycans, an abundant class of carbohydrate-modified proteins found on cell surfaces and in the extracellular matrix, suppress basal levels of autophagy in several cell types during development in Drosophila melanogaster. In studies reported here, we examined the capacity of heparan sulfate synthesis to influence events affected by autophagy, including lifespan, resistance to reactive oxygen species (ROS) stress, and accumulation of ubiquitin-modified proteins in the brain. Compromising heparan sulfate synthesis increased autophagy-dependent processes, evident by extended lifespan, increased resistance to ROS, and reduced accumulation of ubiquitin-modified proteins in the brains of ROS exposed adults. The capacity of altering heparan sulfate biosynthesis to protect cells from injury was also evaluated in two different models of neurodegeneration, overexpression of Presenilin and parkin mutants. Presenilin overexpression in the retina produces cell loss, and compromising heparan sulfate biosynthesis rescued retinal patterning and size abnormalities in these animals. parkin is the fly homolog of human PARK2, one of the genes responsible for juvenile onset Parkinson’s Disease. Parkin is involved in mitochondrial surveillance and compromising parkin function results in degeneration of both flight muscle and dopaminergic neurons in Drosophila. Altering heparan sulfate biosynthesis suppressed flight muscle degeneration and mitochondrial dysmorphology, indicating that activation of autophagy-mediated removal of mitochondria (mitophagy) is potentiated in these animals. These findings provide in vivo evidence that altering the levels of heparan sulfate synthesis activates autophagy and can provide protection from a variety of cellular stressors.

scholarly journals Effect of Prolonged Fluconazole Treatment on Candida albicans in Diffusion Chambers Implanted into Mice

2002 ◽  
Vol 46 (10) ◽  
pp. 3175-3179
Author(s):  
Peter G. Sohnle ◽  
Beth L. Hahn
Keyword(s):  
Candida Albicans ◽  
Inflammatory Response ◽  
Inflammatory Cells ◽  
Model System ◽  
Antifungal Drugs ◽  
Yeast Cells ◽  
In Vitro Susceptibility ◽  
Bonferroni Test

ABSTRACT Fluconazole is an azole agent with primarily fungistatic activity in standard in vitro susceptibility tests. The present study was undertaken to develop a diffusion chamber model system in mice in order to study the in vivo effects of prolonged fluconazole treatment on Candida albicans. Chambers containing 100 C. albicans yeast cells were implanted subcutaneously on the flanks of C57BL/6 mice and were then retrieved 6 or 14 weeks later (after fluconazole treatment for 4 or 12 weeks, respectively). Leukocyte counts demonstrated that implantation of the chambers did elicit an inflammatory response but that only small numbers of inflammatory cells were able to enter the chamber interior. Treatment with fluconazole at 10 mg/kg of body weight/day for 12 weeks not only reduced the numbers of viable organisms within the chambers compared to those in untreated mice (mean ± standard deviation of log10 CFU of 0.7 ± 1.2 versus 2.3 ± 2.0; P < 0.001 by the Bonferroni test) but also increased the numbers of chambers that became sterile over the treatment period (14 of 16 versus 6 of 19; P = 0.0009 by the chi-square test). However, treatment for only 4 weeks had minimal effects on the numbers of chamber CFU, and none of the chambers became sterile during this period. Distribution of retrieved organisms between interior fluid and the chamber filters was approximately equal in all the treatment groups. This model system appears to be useful for evaluating the effects of antifungal drugs over prolonged periods in vivo. Its use in the present study demonstrates that fluconazole can increase the rate of sterilization of C. albicans foci that are protected from the host's inflammatory response.

scholarly journals Modulation of Immune Complex–induced Inflammation In Vivo by the Coordinate Expression of Activation and Inhibitory Fc Receptors

1999 ◽  
Vol 189 (1) ◽  
pp. 179-186 ◽  
Author(s):  
Raphael Clynes ◽  
Jay S. Maizes ◽  
Rodolphe Guinamard ◽  
Masao Ono ◽  
Toshiyuki Takai ◽  
...  
Keyword(s):  
Inflammatory Response ◽  
Immune Complexes ◽  
Inflammatory Responses ◽  
Fc Receptors ◽  
Inflammatory Cells ◽  
Neutrophil Infiltration ◽  
Calcium Flux ◽  
Deficient Mice

Autoantibodies and immune complexes are major pathogenic factors in autoimmune injury, responsible for initiation of the inflammatory cascade and its resulting tissue damage. This activation results from the interaction of immunoglobulin (Ig)G Fc receptors containing an activation motif (ITAM) with immune complexes (ICs) and cytotoxic autoantibodies which initiates and propagates an inflammatory response. In vitro, this pathway can be interrupted by coligation to FcγRIIB, an IgG Fc receptor containing an inhibitory motif (ITIM). In this report, we describe the in vivo consequences of FcγRII deficiency in the inflammatory response using a mouse model of IC alveolitis. At subthreshold concentrations of ICs that fail to elicit inflammatory responses in wild-type mice, FcγRII-deficient mice developed robust inflammatory responses characterized by increased hemorrhage, edema, and neutrophil infiltration. Bronchoalveolar fluids from FcγRII−/− stimulated mice contain higher levels of tumor necrosis factor and chemotactic activity, suggesting that FcγRII deficiency lowers the threshold of IC stimulation of resident cells such as the alveolar macrophage. In contrast, complement- and complement receptor–deficient mice develop normal inflammatory responses to suprathreshold levels of ICs, while FcRγ−/− mice are completely protected from inflammatory injury. An inhibitory role for FcγRII on macrophages is demonstrated by analysis of FcγRII−/− macrophages which show greater phagocytic and calcium flux responses upon FcγRIII engagement. These data reveal contrasting roles for the cellular receptors for IgG on inflammatory cells, providing a regulatory mechanism for setting thresholds for IC sensitivity based on the ratio of ITIM to ITAM FcγR expression. Exploiting the FcγRII inhibitory pathway could thus provide a new therapeutic approach for modulating antibody-triggered inflammation.

scholarly journals OX40L blockade protects against inflammation-driven fibrosis

2016 ◽  
Vol 113 (27) ◽  
pp. E3901-E3910 ◽  
Author(s):  
Muriel Elhai ◽  
Jérôme Avouac ◽  
Anna Maria Hoffmann-Vold ◽  
Nadira Ruzehaji ◽  
Olivia Amiar ◽  
...  
Keyword(s):  
Cell Activation ◽  
Immune Cell ◽  
Unmet Need ◽  
Inflammatory Cells ◽  
Industrialized Countries ◽  
Immune Cell Activation ◽  
Proinflammatory Mediators ◽  
Vessel Injury ◽  
Fibrotic Process

Treatment for fibrosis represents a critical unmet need, because fibrosis is the leading cause of death in industrialized countries, and there is no effective therapy to counteract the fibrotic process. The development of fibrosis relates to the interplay between vessel injury, immune cell activation, and fibroblast stimulation, which can occur in various tissues. Immunotherapies have provided a breakthrough in the treatment of immune diseases. The glycoprotein OX40–OX40 ligand (OX40L) axis offers the advantage of a targeted approach to costimulatory signals with limited impact on the whole immune response. Using systemic sclerosis (SSc) as a prototypic disease, we report compelling evidence that blockade of OX40L is a promising strategy for the treatment of inflammation-driven fibrosis. OX40L is overexpressed in the fibrotic skin and serum of patients with SSc, particularly in patients with diffuse cutaneous forms. Soluble OX40L was identified as a promising serum biomarker to predict the worsening of lung and skin fibrosis, highlighting the role of this pathway in fibrosis. In vivo, OX40L blockade prevents inflammation-driven skin, lung, and vessel fibrosis and induces the regression of established dermal fibrosis in different complementary mouse models. OX40L exerts potent profibrotic effects by promoting the infiltration of inflammatory cells into lesional tissues and therefore the release of proinflammatory mediators, thereafter leading to fibroblast activation.

scholarly journals Crocetin Inhibits Lipopolysaccharide-Induced Inflammatory Response in Human Umbilical Vein Endothelial Cells

2016 ◽  
Vol 40 (3-4) ◽  
pp. 443-452 ◽  
Author(s):  
Lei Song ◽  
Chen Kang ◽  
Yuan Sun ◽  
Wenrui Huang ◽  
Wei Liu ◽  
...  
Keyword(s):  
Inflammatory Response ◽  
Immune Cell ◽  
Umbilical Vein ◽  
Vascular Inflammation ◽  
Bioactive Compound ◽  
Human Umbilical Vein ◽  
Umbilical Vein Endothelial Cells ◽  
Natural Herb

Background/Aim: Crocetin is a readily bioavailable and bioactive compound extracted from Saffron. Previous studies indicated its various biomedical properties including antioxidant and anti-coagulation potencies. However, its effect on inflammation, notably within the cardiovascular system, has not been investigated yet. In the present study, we utilized human umbilical vein endothelial cell (HUVEC) to elucidate the effect of Crocetin on vascular inflammation. Methods: Cell viability and toxicity were evaluated by MTT and Lactate dehydrogenase (LDH) assay, respectively. Pro-inflammatory chemokine <under>M</under>onocyte Chemoattractant <under>P</under>rotein-1 (MCP-1) and <under>I</under>nter<under>l</under>eukin-8 (IL-8) expressions were determined by RT-PCR and ELISA. With fluorescence labeled U937 cells, we examined immune cell adhesion to the inflamed HUVEC in vitro, which was further confirmed by the H&amp;E staining in the murine subcutaneous endothelium in vivo. Results: Upon Lipopolysaccharide (LPS)-induced inflammatory response in HUVECs, Crocetin ameliorated cell cytotoxicity, suppressed MCP-1 and IL-8 expressions through blocking NF-κB p65 signaling transduction. Moreover, Crocetin inhibited immune cells adhesion and infiltration to inflamed endothelium, which is a key step in inflammatory vascular injury. Conclusions: These findings suggest that Crocetin, a natural herb extract, is a potent suppressor of vascular endothelial inflammation.

scholarly journals The role of Leishmania GP63 in the modulation of innate inflammatory response to Leishmania major infection

PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0262158
Author(s):  
Aretha Chan ◽  
Jose-Mauricio Ayala ◽  
Fernando Alvarez ◽  
Ciriaco Piccirillo ◽  
George Dong ◽  
...  
Keyword(s):  
Inflammatory Response ◽  
Leishmania Major ◽  
Critical Role ◽  
Protozoan Parasite ◽  
Inflammatory Cells ◽  
Host Cells ◽  
Cell Infection ◽  
Zinc Metalloprotease

Leishmaniasis is a disease caused by the protozoan parasite Leishmania and is known to affect millions of individuals worldwide. In recent years, we have established the critical role played by Leishmania zinc-metalloprotease GP63 in the modulation of host macrophage signalling and functions, favouring its survival and progression within its host. Leishmania major lacking GP63 was reported to cause limited infection in mice, however, it is still unclear how GP63 may influence the innate inflammatory response and parasite survival in an in vivo context. Therefore, we were interested in analyzing the early innate inflammatory events upon Leishmania inoculation within mice and establish whether Leishmania GP63 influences this initial inflammatory response. Experimentally, L. major WT (L. majorWT), L. major GP63 knockout (L. majorKO), or L. major GP63 rescue (L. majorR) were intraperitoneally inoculated in mice and the inflammatory cells recruited were characterized microscopically and by flow cytometry (number and cell type), and their infection determined. Pro-inflammatory markers such as cytokines, chemokines, and extracellular vesicles (EVs, e.g. exosomes) were monitored and proteomic analysis was performed on exosome contents. Data obtained from this study suggest that Leishmania GP63 does not significantly influence the pathogen-induced inflammatory cell recruitment, but rather their activation status and effector function. Concordantly, internalization of promastigotes during early infection could be influenced by GP63 as fewer L. majorKO amastigotes were found within host cells and appear to maintain in host cells over time. Collectively this study provides a clear analysis of innate inflammatory events occurring during L. major infection and further establish the prominent role of the virulence factor GP63 to provide favourable conditions for host cell infection.

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