CLIC1 regulates dendritic cell antigen processing and presentation by modulating phagosome acidification and proteolysis

© 2016, Company of Biologists Ltd. All rights reserved. Intracellular chloride channel protein 1 (CLIC1) participates in inflammatory processes by regulating macrophage phagosomal functions such as pH and proteolysis. Here, we sought to determine if CLIC1 can regulate adaptive immunity by actions on dendritic cells (DCs), the key professional antigen presenting cells. To do this, we first generated bone marrow-derived DCs (BMDCs) from germline CLIC1 gene-deleted (CLIC1-/-) and wild-type (CLIC1+/+) mice, then studied them in vitro and in vivo. We found phagocytosis triggered cytoplasmic CLIC1 translocation to the phagosomal membrane where it regulated phagosomal pH and proteolysis. Phagosomes from CLIC1-/- BMDCs displayed impaired acidification and proteolysis, which could be reproduced if CLIC1+/+, but not CLIC1-/- cells, were treated with IAA94, a CLIC family ion channel blocker. CLIC1-/- BMDC displayed reduced in vitro antigen processing and presentation of full-length myelin oligodendrocyte glycoprotein (MOG) and reduced MOG-induced experimental autoimmune encephalomyelitis. These data suggest that CLIC1 regulates DC phagosomal pH to ensure optimal processing of antigen for presentation to antigen-specific T-cells. Further, they indicate that CLIC1 is a novel therapeutic target to help reduce the adaptive immune response in autoimmune diseases

TGF-b Superfamily Cytokine MIC-1/GDF15 Is a Physiological Appetite and Body Weight Regulator

The TGF-b superfamily cytokine MIC-1/GDF15 circulates in all humans and when overproduced in cancer leads to anorexia/cachexia, by direct action on brain feeding centres. In these studies we have examined the role of physiologically relevant levels of MIC-1/GDF15 in the regulation of appetite, body weight and basal metabolic rate. MIC-1/GDF15 gene knockout mice (MIC-1−/−) weighed more and had increased adiposity, which was associated with increased spontaneous food intake. Female MIC-1−/− mice exhibited some additional alterations in reduced basal energy expenditure and physical activity, possibly owing to the associated decrease in total lean mass. Further, infusion of human recombinant MIC-1/GDF15 sufficient to raise serum levels in MIC-1−/− mice to within the normal human range reduced body weight and food intake. Taken together, our findings suggest that MIC-1/GDF15 is involved in the physiological regulation of appetite and energy storage

Facile control of nanoporosity in Cellulose Acetate using Nickel(II) nitrate additive and water pressure treatment for highly efficient battery gel separators

We succeed in fabricating nearly straight nanopores in cellulose acetate (CA) polymers for use as battery gel separators by utilizing an inorganic hexahydrate (Ni(NO3)2??6H2O) complex and isostatic water pressure treatment. The continuous nanopores are generated when the polymer film is exposed to isostatic water pressure after complexing the nickel(II) nitrate hexahydrate (Ni(NO3)2??6H2O) with the CA. These results can be attributed to the manner in which the polymer chains are weakened because of the plasticization effect of the Ni(NO3)2??6H2O that is incorporated into the CA. Furthermore, we performed extensive molecular dynamics simulation for confirming the interaction between electrolyte and CA separator. The well controlled CA membrane after water pressure treatment enables fabrication of highly reliable cell by utilizing 2032-type coin cell structure. The resulting cell performance exhibits not only the effect of the physical morphology of CA separator, but also the chemical interaction of electrolyte with CA polymer which facilitates the Li-ion in the cell.ope

The MIC-1/GDF15-GFRAL Pathway in Energy Homeostasis: Implications for Obesity, Cachexia, and Other Associated Diseases

MIC-1/GDF15 is a stress response cytokine and a distant member of the transforming growth factor beta (TGFb) superfamily, with no close relatives. It acts via a recently identified receptor called glial-derived neurotrophic factor (GDNF) receptor alpha-like (GFRAL), which is a distant orphan member of the GDNF receptor family that signals through the tyrosine kinase receptor Ret. MIC-1/GDF15 expression and serum levels rise in response to many stimuli that initiate cell stress and as part of a wide variety of disease processes, most prominently cancer and cardiovascular disease. The best documented actions of MIC-1/GDF15 are on regulation of energy homeostasis. When MIC-1/GDF15 serum levels are substantially elevated in diseases like cancer, it subverts a physiological pathway of appetite regulation to induce an anorexia/cachexia syndrome initiated by its actions on hindbrain neurons. These effects make it a potential target for the treatment of both obesity and anorexia/cachexia syndromes, disorders lacking any highly effective, readily accessible therapies. MIC-1/GDF15 and its hindbrain receptor GFRAL can mediate disease-associated anorexia/cachexia syndrome and play an important role in energy homeostasis. They are also involved in the biology of inflammatory diseases and cancer. We comprehensively review the biology, disease associations, and potential diagnostic and therapeutic application of this cytokine

Anorexia/cachexia of chronic diseases: a role for the TGF-beta family cytokine MIC-1/GDF15

Anorexia/cachexia is a common and currently mostly untreatable complication of advanced cancer. It is also a feature of a number of chronic diseases and can also occur as part of the normal ageing process. Over recent years, two different, but sometimes overlapping, processes have been identified to mediate anorexia/cachexia: those that act primarily on muscle reducing its mass and function, and processes that decrease nutrition leading to loss of both fat and muscle. In the case of at least some cancers, the latter process is sometimes driven by marked overexpression of macrophage inhibitory cytokine-1/growth differentiation factor 15 (MIC-1/GDF15). MIC-1/GDF15 is a transforming growth factor beta (TGF-beta) family cytokine that is found in the serum of all normal individuals at an average concentration of about 0.6 ng/ml. Its increased expression in both cancers and other diseases can result in 10-100-fold or more elevation of its serum levels. In experimental animals, serum MIC-1/GDF15 levels at the lower end of this range induce anorexia by direct actions of the circulating cytokine on feeding centres in the brain. Mice with tumours overexpressing MIC-1/GDF15 display decreased food intake, loss of lean and fat mass and cachexia. That this process also mediates anorexia/cachexia in humans is suggested by the fact that there is a direct correlation between the degree of serum MIC-1/GDF15 elevation and the amount of cancer-related weight loss, the first such relationship demonstrated. Further, in experimental animals, weight loss can be reversed by neutralisation of tumour-produced MIC-1/GDF15 with a specific monoclonal antibody, suggesting the possibility of effective therapy of patients with the devastating complication of anorexia/cachexia

The anorectic actions of the TGFβ cytokine MIC-1/GDF15 require an intact brainstem area postrema and nucleus of the solitary tract

Macrophage inhibitory cytokine-1 (MIC-1/GDF15) modulates food intake and body weight under physiological and pathological conditions by acting on the hypothalamus and brainstem. When overexpressed in disease, such as in advanced cancer, elevated serum MIC-1/GDF15 levels lead to an anorexia/cachexia syndrome. To gain a better understanding of its actions in the brainstem we studied MIC-1/GDF15 induced neuronal activation identified by induction of Fos protein. Intraperitoneal injection of human MIC-1/GDF15 in mice activated brainstem neurons in the area postrema (AP) and the medial (m) portion of the nucleus of the solitary tract (NTS), which did not stain with tyrosine hydroxylase (TH). To determine the importance of these brainstem nuclei in the anorexigenic effect of MIC-1/GDF15, we ablated the AP alone or the AP and the NTS. The latter combined lesion completely reversed the anorexigenic effects of MIC-1/GDF15. Altogether, this study identified neurons in the AP and/or NTS, as being critical for the regulation of food intake and body weight by MIC-1/GDF15. © 2014 Tsai et al

Macrophage inhibitory cytokine-1/growth differentiation factor-15 as a predictor of colonic neoplasia

Background: Serum macrophage inhibitory cytokine-1 (MIC-1/GDF15) concentration has been associated with colonic adenomas and carcinoma. Aims: To determine whether circulating MIC-1/GDF15 serum concentrations are higher in the presence of adenomas and whether the level decreases after excision. Methods: Patients were recruited prospectively from a single centre and stratified into five groups: no polyps (NP); hyperplastic polyps (HP); sessile serrated ademona (SSA); adenomas (AP); and colorectal carcinoma (CRC). Blood samples were collected immediately before and 4 weeks after colonoscopy. MIC-1/GDF15 serum levels were quantified using ELISA. Results: Participants (n=301) were stratified as: NP; n=116 (52%), HP; n=37 (12%), SSA; n=19 (7%), AP; n=68 (23%); and CRC; n=3 (1%). Patients were excluded from the study due to nondiagnostic pathology (n=9, 3%) and exclusion criteria (n=20, 6%). In the 272 remaining subjects (M=149; F=123), age (P=.005), history of colonic polyps (P=.003) and family history of colonic polyps (P=.002) were associated with presence of adenomas. Baseline median MIC-1/GDF15 serum levels increased significantly from NP 609 (460-797) pg/mL, HP 582 (466-852) pg/mL, SSA 561 (446-837) pg/mL to AP 723 (602-1122) pg/mL and CRC 1107 (897-1107) pg/mL; (P<.001). In the pre- and postpolypectomy paired adenoma samples median MIC-1/GDF15 reduced significantly from 722 (603-1164) pg/mL to 685 (561-944) pg/mL (P=.002). A ROC analysis for serum MIC-1/GDF15 to identify adenomatous polyps indicated an area under the curve of 0.71. Conclusions: Our data suggest that serum MIC-1/GDF15 has the diagnostic characteristics to increase the detection of colonic neoplasia and improve screening

TGF-b Superfamily Cytokine MIC-1/GDF15 Is a Physiological Appetite and Body Weight Regulator

The TGF-b superfamily cytokine MIC-1/GDF15 circulates in all humans and when overproduced in cancer leads to anorexia/cachexia, by direct action on brain feeding centres. In these studies we have examined the role of physiologically relevant levels of MIC-1/GDF15 in the regulation of appetite, body weight and basal metabolic rate. MIC-1/GDF15 gene knockout mice (MIC-1&#8722;/&#8722;) weighed more and had increased adiposity, which was associated with increased spontaneous food intake. Female MIC-1&#8722;/&#8722; mice exhibited some additional alterations in reduced basal energy expenditure and physical activity, possibly owing to the associated decrease in total lean mass. Further, infusion of human recombinant MIC-1/GDF15 sufficient to raise serum levels in MIC-1&#8722;/&#8722; mice to within the normal human range reduced body weight and food intake. Taken together, our findings suggest that MIC-1/GDF15 is involved in the physiological regulation of appetite and energy storage

Hydroxychloroquine plus personal protective equipment versus standard personal protective equipment alone for the prevention of COVID-19 infections among frontline healthcare workers: The HydrOxychloroquine Prophylaxis Evaluation(HOPE) trial: A structured summary of a study protocol for a randomized controlled trial

Objectives: To evaluate the effect of the combination of hydroxychloroquine (HCQ) and standard personal protective equipment (PPE) compared to the use of standard personal protective equipment alone on the proportion of laboratory confirmed COVID-19 infections among frontline healthcare workers(HCWs) in India Trial design: HOPE is an investigator initiated multi-centre open-label parallel group randomized controlled trial. Participants: All HCWs currently working in an environment with direct exposure to patients with confirmed COVID-19 infection are eligible to participate in the trial. The trial aims to be conducted across 20-30 centres (public and private hospitals) in India. HCWs who decline consent, who have a confirmed COVID-19 infection, those who are already on chloroquine/HCQ for any indication, or if pregnant or breast-feeding, or have known QT prolongation or are on medications that when taken with HCQ can prolong the QTc will be excluded. Intervention and comparator: The interventions to be compared in this trial are standard practice (use of recommended PPE) and HCQ plus standard practice. In the standard practice arm, HCWs will use recommended PPE as per institutional guidelines and based on their roles. They will be discouraged from taking HCQ to prevent contamination and contacted every week for the duration of the study to ascertain if they have taken any HCQ. Any such use will be reported as a protocol violation. In the intervention arm, HCWs will be administered 800mg of HCQ as a loading dose on the day of randomization (as two 400mg doses 12hrs apart) and subsequently continued on 400mg once a week for 12 weeks. This will be in addition to the use of recommended PPE as per institutional guidelines and based on their roles. HCWs will collect the drug once every week from designated research and pharmacy staff at site. A weekly phone reminder will be provided to participants in this arm to ensure compliance. An ECG will be performed between 4-6 weeks in this arm and if the QTc is prolonged (greater than 450milliseconds), the drug will be stopped. Follow-up will however continue. Participants in both arms will receive a weekly phone call for evaluation of the primary outcome, to monitor protocol compliance and development of any adverse events (in the HCQ group). Main outcomes: Participants will be followed on a weekly basis. The primary outcome is the proportion of HCWs developing laboratory confirmed COVID-19 infection within 6 months of randomization. We will also evaluate a number of secondary outcomes, including hospitalization related to suspected/confirmed COVID-19 infection, intensive care unit or high-dependency unit admission due to suspected/confirmed COVID-19 infection, all-cause mortality, need for organ support (non-invasive or invasive ventilation, vasopressors and renal replacement therapy), ICU and hospital length of stay, readmission, days off work and treatment-related adverse events. Randomisation: Randomisation will be conducted through a password-protected, secure website using a central, computer-based randomisation program. Randomisation will be stratified by participating institutions and by the role of HCW - nursing, medical and other. Participants will be randomised 1:1 to either standard practice only or HCQ plus standard practice. Allocation concealment is maintained by central web-based randomisation Blinding (masking): This is an unblinded study: study assigned treatment will be known to the research team and participant. Bias will be mitigated through an objective end point (laboratory confirmed COVID-19 infection). Numbers to be randomised (sample size): A total of 6,950 HCWs will be enrolled (3475 to the intervention) and (3475 to the standard practice group) to detect a 25% relative reduction, or 2.5% absolute reduction, in the infection rate from an estimated baseline infection rate of 10%, with 80% statistical power using a two-sided test at 5% level of significance. Available data from China and Italy indicate that the rate of infection among frontline healthcare workers varies between 4% to 12%. We therefore assumed a baseline infection rate of 10% among HCWs. This sample size allows for a potential loss to follow-up rate of 10% and a potential non-compliance rate of 10% in both the treatment and control arms. Trial Status: HOPE protocol version 3.0 dated June 3rd 2020. Recruitment started on 29th June 2020 and currently 56 participants have been enrolled. Planned completion of enrolment is January 31st 2021. Trial registration: Clinical Trials Registry of India: CTRI/2020/05/025067 (prospectively registered) Date of registration: 6th May 2020 Full protocol: The full protocol is attached as an additional file, accessible from the Trials website (Additional file 1). In the interest of expedited dissemination of this material, the familiar formatting has been eliminated; this Letter serves as a summary of the key elements of the full protocol. The study protocol has been reported in accordance with the Standard Protocol Items: Recommendations for Clinical Interventional Trials (SPIRIT) guidelines (Additional file 2)