Both innate and adaptive immune cells are critical players in autoimmune destruction of insulin-producing β-cells in type 1 diabetes. However, the early pathogenic events triggering the recruitment and activation of innate immune cells in islets remain obscure. Here we show that circulating fatty acid binding protein 4 (FABP4) level is significantly elevated in type1 diabetes patients and their first-degree relatives, and positively correlates with the titers of several islet autoantibodies. In non-obese diabetic (NOD) mice, increased FABP4 expression in islet macrophages starts from the neonatal period, well before the occurrence of overt diabetes. Furthermore, the spontaneous development of autoimmune diabetes in NOD mice is markedly reduced by pharmacological inhibition or genetic ablation of FABP4, or adoptive transfer of FABP4-deficient bone marrow cells. Mechanistically, FABP4 activates innate immune responses in islets by enhancing the infiltration and polarization of macrophages to pro-inflammatory M1 subtype, thus creating an inflammatory milieu required for activation of diabetogenic CD8+ T cells and shift of CD4+ helper T cells towards the Th1 subtypes. These findings demonstrate FABP4 as an early mediator for β-cell autoimmunity by facilitating crosstalk between innate and adaptive immune cells, suggesting that pharmacological inhibition of FABP4 may represent a promising therapeutic strategy for autoimmune diabetes.
Yang Xiao, Lingling Shu, Xiaoping Wu, Yang Liu, Lai Yee Cheong, Boya Liao, Xiaoyu Xiao, Ruby L.C. Hoo, Zhiguang Zhou, Aimin Xu
AbstractMillions of people are affected by hearing loss. When hearing loss is caused by noise or aging, it is often associated with breakdown of the barrier between the cochlea and its blood vessels. Pericytes populate many small vessels in the adult inner ear, however, their role in different forms of hearing loss is largely unknown. Using an inducible and conditional pericyte depletion mouse model, we show that loss of pericytes leads to marked changes in vascular structure, resulting in poor blood circulation and hearing loss. In vitro, using advanced tissue explants from pericyte fluorescence reporter models in combination with exogenous donor pericytes, we show pericytes, signaled by endothelial growth factor isoform A165 (VEGF-A165), vigorously drives new vessel growth in both adult and neonatal mouse inner ear tissue. In vivo, the delivery of an adeno-associated virus serotype 1 (AAV1)-mediated VEGF-A165 viral vector to pericyte depleted animals regenerated lost pericytes, improved blood supply, reduced loss of sensory hair cells, and attenuated hearing loss. These studies provide the first clear-cut evidence that pericytes are critical for adult hearing and can regenerate cochlear vasculature. The restoration of vascular function in the damaged inner ear with AAV1-mediated VEGF-A165 gene therapy is a new strategy for ameliorating vascular associated hearing disorders, including common forms of age-related hearing loss.
Jinhui Zhang, Zhiqiang Hou, Xiaohan Wang, Han Jiang, Lingling Neng, Yunpei Zhang, Qing Yu, George W. S. Burwood, Junha Song, Manfred Auer, Anders Fridberger, Michael Hoa, Xiaorui Shi
Liver regeneration is critical to survival after traumatic injuries, exposure to hepatotoxins, or surgical interventions, yet the underlying signaling and metabolic pathways remain unclear. Here we show that hepatocyte-specific loss of the mitochondrial deacetylase SIRT3 drastically impairs regeneration and worsens mitochondrial function after partial hepatectomy. Sirtuins, including SIRT3, require nicotinamide adenine dinucleotide (NAD) as a cosubstrate. We previously showed that the NAD precursor nicotinamide riboside (NR) promotes liver regeneration, but whether this involves sirtuins has not been tested. Here we show that despite their NAD-dependence and critical roles in regeneration, neither SIRT3 nor its nuclear counterpart SIRT1 is required for NR to enhance liver regeneration. NR improves mitochondrial respiration in regenerating wild type or mutant livers and rapidly increases oxygen consumption and glucose output in cultured hepatocytes. Our data support a direct enhancement of mitochondrial redox metabolism as the mechanism mediating improved liver regeneration after NAD supplementation and exclude signaling via SIRT1 and SIRT3. Thus, we provide the first evidence for an essential role for a mitochondrial sirtuin during liver regeneration and insight into the beneficial effects of NR.
Sarmistha Mukherjee, James Mo, Lauren M. Paolella, Caroline E. Perry, Jade Toth, Mindy M. Hugo, Qingwei Chu, Qiang Tong, Karthikeyani Chellappa, Joseph A. Baur
ORM1-like 3 (ORMDL3) has strong genetic linkage to childhood onset asthma. To determine whether ORMDL3 selective expression in airway smooth muscle (ASM) influences ASM function we used cre/lox techniques to generate transgenic mice (hORMDL3Myh11eGFP-cre) which express human ORMDL3 selectively in smooth muscle cells. In vitro studies of ASM cells isolated from the bronchi of hORMDL3Myh11eGFP-cre mice demonstrated that they developed hypertrophy (quantitated by FACS and image analysis), hyperplasia (assessed by BrdU incorporation), and expressed increased levels of tropomysin proteins TPM1 and TPM4. siRNA knockdown of TPM1 or TPM4 demonstrated their importance to ORMDL3 mediated ASM proliferation but not hypertrophy. In addition, ASM derived from hORMDL3Myh11eGFP-cre mice had increased contractility to histamine in vitro which was associated with increased levels of intracellular Ca2+, increased cell surface membrane Orai1 Ca2+ channels which mediate influx of Ca2+ into the cytoplasm, and increased expression of ASM contractile genes Serca2b and Sm22. In vivo studies of hORMDL3Myh11eGFP-cre mice demonstrated that they had a spontaneous increase in ASM and AHR. ORMDL3 expression in ASM thus induces changes in ASM (hypertrophy, hyperplasia, increased contractility) which may explain the contribution of ORMDL3 to the development of AHR in childhood onset asthma which is highly linked to ORMDL3 on chromosome 17q12-21.
Alexa K. Pham, Marina Miller, Peter Rosenthal, Sudipta Das, Ning Weng, Sunghoon Jang, Richard C. Kurten, Jana Badrani, Taylor A. Doherty, Brian G. Oliver, David H. Broide
During denervation induced muscle atrophy, the loss of neuro-muscular junction (NMJ) integrity and the consequent cessation of nerve signal transmission to muscle, lead to a decline in myofiber size mass and contractile activity. However, the identity of the cell types implicated in the muscle response to nerve injury has not been clearly defined. Here, we describe a subpopulation of muscle resident glial cells activated by loss of NMJ integrity. Gene expression analysis at bulk and single cell level revealed the existence of a population of Itga7-expressing cells, which are distinct from muscle satellite cells and are selectively activated upon nerve injury. Upon nerve lesion, these cells expanded and activated a neurotrophic gene program, including the expression of a prospective selection marker – Ngfr – and a number of neurotrophic genes as well as ECM components. Among them, we observed that Tenascin C (Tnc) was specifically produced by muscle glial cells activated by nerve injury and preferentially localized to NMJ. Activation of muscle-resident glial cells by nerve injury induced a neurotrophic phenotype, which was reversible upon recovery of NMJ integrity; by contrast, muscle-resident glial cells in skeletal muscles of a mouse model of Amyotrophic Lateral Sclerosis (ALS) steadily increased over the course of the disease and exhibited an impaired neurotrophic activity, suggesting that pathogenic activation of glial cells may be implicated in ALS progression.
Daisy Proietti, Lorenzo Giordani, Marco De Bardi, Chiara D'Ercole, Biliana Lozanoska-Ochser, Susanna Amadio, Cinzia Volontè, Sara Marinelli, Antoine Muchir, Marina Bouchè, Giovanna Borsellino, Alessandra Sacco, Pier Lorenzo Puri, Luca Madaro
Secretory protein misfolding has been linked to ER stress and cell death. We expressed a TGrdw transgene encoding TG-G(2298)R, a misfolded mutant thyroglobulin reported to be linked to thyroid cell death. When the TGrdw transgene was expressed at low-level in thyrocytes of TGcog/cog mice that experience severe ER stress, we observed increased thyrocyte cell death and increased expression of CIDE-A (Cell death-inducing DFFA-like effector-A, a protein of lipid droplets) in whole thyroid gland. Here we demonstrate that acute ER stress in cultured PCCL3 thyrocytes increases Cidea mRNA levels, maintained at least in part by increased mRNA stability, while being negatively regulated by ATF6 — with similar observations other cell types. CIDE-A protein is sensitive to proteasomal degradation yet is stabilized by ER stress, and elevated expression levels accompany increased cell death. Unlike acute ER stress, PCCL3 cells adapted and surviving chronic ER stress maintain a disproportionately lower relative mRNA level of Cidea compared to that of other, classical ER stress markers, as well as a blunted Cidea mRNA response to a new, unrelated acute ER stress challenge. We suggest that CIDE-A is a novel marker linked to a non-canonical ER stress-response program, with implications for cell death and survival.
Yoshiaki Morishita, Aaron P. Kellogg, Dennis Larkin, Wei Chen, Suryakiran Vadrevu, Leslie S. Satin, Ming Liu, Peter Arvan
Gene replacement for Duchenne muscular dystrophy (DMD) with micro-dystrophins has entered clinical trials, but efficacy on preventing heart failure is unknown. Although most DMD patients die from heart failure, cardiomyopathy is undetectable until the teens so efficacy from trials in young boys will be unknown for a decade. Available DMD animal models were sufficient to demonstrate micro-dystrophin efficacy on earlier onset skeletal muscle pathology underlying loss of ambulation and respiratory insufficiency in patients. However, no mouse models progressed into heart failure and dog models show highly variable progression insufficient to evaluate efficacy of micro-dystrophin or other therapies on DMD heart failure. To overcome this barrier, we have generated the first DMD mouse model that reproducibly progresses into heart failure. This model shows cardiac inflammation and fibrosis occur prior to reduced function. Fibrosis does not continue to accumulate, but inflammation persists after function declines. We used this model to test micro-dystrophin gene therapy efficacy on heart failure prevention for the first time. Micro-dystrophin prevents declines in cardiac function and prohibits onset of inflammation and fibrosis. This model will allow identification of committed pathogenic steps to heart failure and testing of genetic and non-genetic therapies to optimize cardiac care for DMD patients.
Zachary M. Howard, Lisa E. Dorn, Jeovanna Lowe, Megan D. Gertzen, Pierce C. Ciccone, Neha Rastogi, Guy L. Odom, Federica Accornero, Jeffrey S. Chamberlain, Jill A. Rafael-Fortney
There are approximately 44,000 cases of human papilloma virus (HPV)‒associated cancer each year in the United States, most commonly caused by HPV16/18. Prophylactic vaccines successfully prevent healthy people from acquiring HPV infections via HPV-specific antibodies. To treat established HPV-associated malignancies, however, new therapies are necessary. Multiple recombinant gorilla adenovirus HPV vaccine constructs were evaluated in NSG β2m-/- peripheral blood mononuclear cell–humanized mice bearing SiHa, a human HPV16+ cervical tumor, and/or in the syngeneic HPV16+ TC-1 model. PRGN-2009 is a new therapeutic gorilla adenovirus HPV vaccine containing multiple cytotoxic T-cell epitopes of the viral oncoproteins HPV 16/18 E6 and E7, including T-cell enhancer agonist epitopes. PRGN-2009 treatment reduced tumor volume and increased CD8 and CD4 T cells in the tumor microenvironment of humanized mice bearing the human cervical tumor SiHa. PRGN-2009 monotherapy in the syngeneic TC-1 model also reduced tumor volumes and weights, generated high levels of HPV16 E6-specific T cells, and increased multifunctional CD8 and CD4 T cells in the tumor microenvironment. These studies provide the first evaluation of a therapeutic gorilla adenovirus HPV vaccine, PRGN-2009, showing promising preclinical anti-tumor efficacy and induction of HPV-specific T cells, and the rationale for its evaluation in clinical trials.
Samuel T. Pellom, Claire Smalley Rumfield, Y. Maurice Morillon II, Nicholas Roller, Lisa K. Poppe, Douglas E. Brough, Helen Sabzevari, Jeffrey Schlom, Caroline Jochems
Chronic inflammation and immune dysfunction play a key role in the development of non-AIDS related comorbidities. The aim of our study was to characterize the functional phenotype of immune cells in people living with HIV (PLHIV). We enrolled a cross-sectional cohort study of PLHIV on stable antiretroviral therapy and healthy controls. We assessed ex vivo cytokine production capacity and transcriptomics of monocytes and T-cells upon bacterial, fungal and viral stimulation. PLHIV exhibited an exacerbated pro-inflammatory profile in monocyte-derived cytokines, but not in lymphocyte-derived cytokines. Particularly, the production of the IL-1β to imiquimod, E. coli LPS and Mycobacterium tuberculosis was increased, and this production correlated with plasma concentrations of hsCRP and sCD14. This increase in monocyte responsiveness remained stable over time in subsequent blood sampling after >1year. Transcriptome analyses confirmed priming of the monocyte IL-1β pathway, consistent with a monocyte trained immunity phenotype. Increased plasma concentrations of β-glucan, a well-known inducer of trained immunity, were associated with increased innate cytokine responses. Monocytes of PLHIV exhibit a sustained pro-inflammatory immune phenotype with priming of the IL-1β pathway. Training of the innate immune system in PLHIV likely plays a role in long-term HIV complications and provides a promising therapeutic target for inflammation-related comorbidities.
Wouter A. van der Heijden, Lisa van de Wijer, Farid Keramati, Wim Trypsteen, Sofie Rutsaert, Rob ter Horst, Martin Jaeger, Hans J.P.M. Koenen, Hendrik G. Stunnenberg, Irma Joosten, Paul E. Verweij, Jan van Lunzen, Charles A. Dinarello, Leo A.B. Joosten, Linos Vandekerckhove, Mihai G. Netea, André J. van der Ven, Quirijn de Mast
Primary Graft Dysfunction (PGD) is the predominant cause of early graft loss following lung transplantation. We recently demonstrated that donor pulmonary intravascular non-classical monocytes (NCM) initiate neutrophil recruitment. Simultaneously, host-origin classical monocytes (CM) permeabilize the vascular endothelium to allow neutrophil extravasation necessary for PGD. Here, we show that a CCL2-CCR2 axis is necessary for CM recruitment. Surprisingly, although intravital imaging and multichannel flowcytometry revealed that depletion of donor NCM abrogated CM recruitment, single-cell RNA-seq identified donor alveolar macrophages (AM) as predominant CCL2 secretors. Unbiased transcriptomic analysis of murine tissues combined with murine knockouts and chimeras indicated that IL1β production by donor NCM was responsible for the early activation of AM and CCL2 release. IL1β production by NCM was NLRP3 inflammasome-dependent and inhibited by treatment with a clinically approved sulphonylurea. Production of CCL2 in the donor AM occurred through IL1R-dependent activation of the PKC and NFκB-pathway. Accordingly, we show that IL1β-dependent paracrine interaction between donor NCM and AM leads to recruitment of recipient CM necessary for PGD. Since depletion of donor NCM, IL1β or IL1R antagonism, and inflammasome inhibition, abrogated recruitment of CM as well as PGD, and are feasible using FDA-approved compounds, our findings may have potential for clinical translation.
Chitaru Kurihara, Emilia Lecuona, Qiang Wu, Wenbin Yang, Felix L. Nunez-Santana, Mahzad Akbarpour, Xianpeng Liu, Ziyou Ren, Wenjun Li, Melissa Querrey, Sowmya Ravi, Megan L. Anderson, Emily Cerier, Haiying Sun, Megan E. Kelly, Hiam Abdala-Valencia, Ali Shilatifard, Thalachallour Mohanakumar, G.R. Scott Budinger, Daniel Kreisel, Ankit Bharat
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