The pathogenesis of Chronic Obstructive Pulmonary Disease (COPD) involves aberrant responses to cellular stress caused by chronic cigarette smoke (CS) exposure. However, not all smokers develop COPD and the critical mechanisms that regulate cellular stress responses to increase COPD susceptibility are not understood. Because microRNAs are well-known regulators of cellular stress responses, we evaluated microRNA expression arrays performed on distal parenchymal lung tissue samples from 172 subjects with and without COPD. We identified miR-24-3p as the microRNA that best correlated with radiographic emphysema (ρ=-0.353, P=1.3e-04), and validated this finding in multiple cohorts. In a CS-exposure mouse model, inhibition of miR-24-3p increased susceptibility to apoptosis, including alveolar type II epithelial cell (AECII) apoptosis, and emphysema severity. In lung epithelial cells, miR-24-3p suppressed apoptosis through the BH3-only protein BIM and suppressed homology-directed DNA repair and the DNA repair protein BRCA1. Finally, we found BIM and BRCA1 are increased in COPD lung tissue, and BIM and BRCA1 expression inversely correlate with miR-24-3p. We concluded that miR-24-3p, a regulator of the cellular response to DNA damage, is decreased in COPD, and decreased miR-24-3p increases susceptibility to emphysema through increased BIM and apoptosis.
Jessica Nouws, Feng Wan, Eric Finnemore, Willy Roque, So-Jin Kim, Isabel S. Bazan, Chuan-Xing Li, C. Magnus Sköld, Qile Dai, Xiting Yan, Maurizio Chioccioli, Veronique Neumeister, Clemente J. Britto, Joann Sweasy, Ranjit S. Bindra, Åsa M. Wheelock, Jose L. Gomez, Naftali Kaminski, Patty J. Lee, Maor Sauler
Activation of Farnesoid-X-Receptor (FXR) by obeticholic acid (OCA) reduces hepatic inflammation and fibrosis in patients with primary biliary cholangitis (PBC), a life-threatening cholestatic liver failure. Inhibition of bromodomain-containing protein-4 (BRD4) also has anti-inflammatory, anti-fibrotic effects in mice. We determined the role of BRD4 in FXR function in bile acid (BA) regulation and examined whether the known beneficial effects of OCA are enhanced by inhibiting BRD4 in cholestatic mice. Liver-specific downregulation of BRD4 disrupted BA homeostasis in mice, and FXR-mediated regulation of BA-related genes, including Shp and Cyp7a1, was BRD4-dependent. In cholestatic mice, JQ1 or OCA treatment ameliorated hepatotoxicity, inflammation, and fibrosis, but surprisingly, was antagonistic in combination. Mechanistically, OCA increased binding of FXR and the corepressor SMRT, decreased NF-κB binding at inflammatory genes, and repressed the genes in a BRD4-dependent manner. In PBC patients, hepatic expression of FXR and BRD4 was significantly reduced. In conclusion, BRD4 is a novel cofactor of FXR for maintaining BA homeostasis and hepatoprotection. While BRD4 promotes hepatic inflammation and fibrosis in cholestasis, paradoxically, BRD4 is required for the anti-inflammatory, anti-fibrotic actions of OCA-activated FXR. Co-treatment with OCA and JQ1, individually beneficial, may be antagonistic in treatment of liver disease patients with inflammation and fibrosis complications.
Hyunkyung Jung, Jinjing Chen, Xiangming Hu, Hao Sun, Shwu-Yuan Wu, Cheng-Ming Chiang, Byron Kemper, Lin-Feng Chen, Jongsook Kemper
Background. Neuronal hyper-excitability characterizes the early stages of Alzheimer’s disease (AD). In animals, early misfolded tau and amyloid-beta (Aβ) protein accumulation, both central to AD neuropathology, promote cortical excitability and neuronal network dysfunction. In healthy humans, misfolded tau and Aβ aggregates are first detected, respectively, in the brainstem and frontomedial and temporobasal cortices, decades prior to the onset of AD cognitive symptoms. Whether cortical excitability is related to early brainstem tau, and its associated neuroinflammation, and cortical Aβ aggregations remains unknown. Methods. We probed frontal cortex excitability, using transcranial magnetic stimulation combined with electroencephalography, in a sample of 64 healthy late middle-aged individuals (50-69 y; 45 women). We assessed whole-brain [18F]THK5351 positron emission tomography (PET) uptake as a proxy measure of tau/neuroinflammation, and whole-brain Aβ burden with [18F]Flutemetamol or [18F]Florbetapir radiotracers. Results. We find that higher [18F]THK5351 uptake in a brainstem monoaminergic compartment is associated with increased cortical excitability (r = .29, p = .02). By contrast, [18F]THK5351 PET signal in the hippocampal formation, although strongly correlated with brainstem signal in whole-brain voxel-based quantification analyses (pFWE-corrected < .001), was not significantly associated with cortical excitability (r = .14, p = .25). Importantly, no significant association was found between early Aβ cortical deposits and cortical excitability (r = -.20, p = .11). Conclusion. These findings reveal potential brain substrates for increased cortical excitability in preclinical AD and may constitute functional in vivo correlates of early brainstem tau accumulation and neuroinflammation in humans. Trial registration. EudraCT 2016-001436-35. Funding. F.R.S.-FNRS Belgium, Wallonie-Bruxelles International, ULiège, Fondation Simone et Pierre Clerdent, European Regional Development Fund.
Maxime Van Egroo, Daphne O. Chylinski, Justinas Narbutas, Gabriel Besson, Vincenzo Muto, Christina Schmidt, Davide Marzoli, Paolo Cardone, Nora Vandeleene, Martin Grignard, André Luxen, Eric Salmon, Christian Lambert, Christine Bastin, Fabienne Collette, Christophe Phillips, Pierre Maquet, Mohamed Ali Bahri, Evelyne Balteau, Gilles Vandewalle
Idiopathic pulmonary fibrosis (IPF) is a progressive, irreversible fibrotic disease of the distal lung alveoli that culminates in respiratory failure and reduced lifespan. Unlike normal lung repair in response to injury, IPF is associated with the accumulation and persistence of fibroblasts and myofibroblasts and continued production of collagen and other extracellular matrix (ECM) components. Prior in vitro studies have led to the hypothesis that the development of resistance to Fas-induced apoptosis by lung fibroblasts and myofibroblasts contibributes to their accumulation in the distal lung tissues of IPF patients. Here, we test this hypothesis in vivo in the resolving model of bleomycin-induced pulmonary fibrosis in mice. Using genetic loss-of-function approaches to inhibit Fas signaling in fibroblasts, novel flow cytometry strategies to quantify lung fibroblast subsets and transcriptional profiling of lung fibroblasts by bulk and single cell RNA-sequencing, we show that Fas is necessary for lung fibroblast apoptosis during homeostatic resolution of bleomycin-induced pulmonary fibrosis in vivo. Furthermore, we show that loss of Fas signaling leads to the persistence and continued pro-fibrotic functions of lung fibroblasts. Our studies provide novel insights into the mechanisms that contribute to fibroblast survival, persistence and continued ECM deposition in the context of IPF and how failure to undergo Fas-induced apoptosis prevents fibrosis resolution.
Elizabeth F. Redente, Sangeeta Chakraborty, Satria P. Sajuthi, Bart P. Black, Ben L. Edelman, Max A. Seibold, David W.H. Riches
Current treatments for pneumonia (PNA) are focused on the pathogens. Mortality from PNA-induced acute lung injury (PNA-ALI) remains high, underscoring the need for additional therapeutic targets. Clinical and experimental evidence exists for potential sex differences in PNA survival, with males having higher mortality. In a model of severe pneumococcal PNA, when compared to males, age-matched female mice exhibited enhanced resolution characterized with decreased alveolar and lung inflammation and increased numbers of Regulatory T cells (Tregs). Recognizing the critical role of Tregs in lung injury resolution, we evaluated if improved outcomes in females were due to estradiol (E2) effects on Treg biology. E2 promoted Treg suppressive phenotype in vitro and resolution of PNA in vivo. Systemic rescue administration of E2 promoted resolution of PNA in males independent of lung bacterial clearance. E2 augmented Treg expression of Foxp3, CD25 and GATA3, an effect that required ERb, and not ERa signaling. Importantly, the in vivo therapeutic effects of E2 were lost in Treg depleted mice (Foxp3DTR). Adoptive transfer of ex vivo E2-treated Tregs rescued S. pneumoniae-induce PNA-ALI, a salutary effect that required Treg ERβ expression. E2-ERβ was required for Tregs to control macrophage pro-inflammatory responses. Our findings support the therapeutic role for E2 in promoting resolution of lung inflammation after PNA via ERβ Tregs.
Ye Xiong, Qiong Zhong, Tsvi Palmer, Alison Benner, Lan Wang, Karthik Suresh, Rachel Damico, Franco R. D'Alessio
Esophageal Adenocarcinoma (EAC) develops from Barrett’s Esophagus (BE), a chronic inflammatory state that can progress through a series of transformative dysplastic states before tumor development. While molecular and genetic changes of EAC tumors have been studied, immune microenvironment changes during Barrett’s progression to EAC remain poorly understood. In this study, we identify potential immunologic changes which can occur during BE to EAC progression. RNA Sequencing (RNA-Seq) analysis on tissue samples from EAC patients undergoing surgical resection demonstrated that a subset of chemokines and cytokines, most notably IL-6 and IL-8, increased during BE progression to EAC. xCell deconvolution analysis investigating immune cell population changes demonstrated that the largest changes in expression during BE progression occurred in M2 macrophages, pro B-cells, and eosinophils. Multiplex immunohistochemical staining of tissue microarrays showed increased immune cell populations during Barrett’s progression to high grade dysplasia. In contrast, EAC tumor sections were relatively immune poor, with a rise in PD-L1 expression and loss of CD8+ T-cells. These data demonstrate the EAC microenvironment is characterized by poor cytotoxic effector cell infiltration and increased immune inhibitory signaling. These findings suggest an immune suppressive microenvironment, highlighting the need for further studies to explore immune modulatory therapy in EAC.
Kiran H. Lagisetty, Dyke P. McEwen, Derek J. Nancarrow, Johnathon G. Schiebel, Daysha Ferrer-Torres, Dipankar Ray, Timothy L. Frankel, Jules Lin, Andrew C. Chang, Laura A. Kresty, David G. Beer
Extra-pulmonary manifestations of COVID-19 are associated with a much higher mortality rate. Yet, little is known about the pathogenesis of systemic complications of COVID-19. Here, we create a murine model of SARS-CoV-2 induced severe systemic toxicity and multi-organ involvement by expressing the human ACE2 transgene in multiple tissues via viral delivery followed by systemic administration of SARS-CoV-2. The animals develop a profound phenotype within 7 days with severe weight loss, morbidity and failure to thrive. We demonstrate there is metabolic suppression of oxidative phosphorylation and the tri-carboxylic acid (TCA) cycle in multiple organs with neutrophilia, lymphopenia and splenic atrophy mirroring human COVID-19 phenotypes. Animals had a significantly lower heart rate and electron microscopy demonstrated myofibrillar disarray and myocardial edema, a common pathogenic cardiac phenotype in human COVID-19. We perform metabolomic profiling of peripheral blood and identify a panel of TCA cycle metabolites that serve as biomarkers of depressed oxidative phosphorylation. Finally, we observed that SARS-CoV-2 induces epigenetic changes of DNA methylation, that affects expression of immune response genes and could in part contribute to COVID-19 pathogenesis. Our model suggests that SARS-CoV-2 induced metabolic reprogramming and epigenetic changes in internal organs could contribute to systemic toxicity and lethality in COVID-19.
Shen Li, Feiyang Ma, Tomohiro Yokota, Gustavo Garcia Jr., Amelia Palermo, Yijie Wang, Colin Farrell, Yu-Chen Wang, Rimao Wu, Zhiqiang Zhou, Calvin Pan, Marco Morselli, Michael A. Teitell, Sergey Ryazantsev, Gregory A. Fishbein, Johanna ten Hoeve, Valerie A. Arboleda, Joshua Bloom, Barbara J. Dillon, Matteo Pellegrini, Aldons J. Lusis, Thomas G. Graeber, Vaithilingaraja Arumugaswami, Arjun Deb
Those under the age of 6 months are at significant risk from influenza virus infection; however, there is currently no vaccine approved for this age group. Influenza virus neuraminidase has emerged as a potential additional target for vaccine strategies. In this study, we sought to understand the ability of newborns to mount an antibody response to neuraminidase. Here we employed a nonhuman primate model given the similarities to humans in the immune system and development. We measured antibody to neuraminidase following infection with an H1N1 virus or following vaccination and challenge. Administration of an inactivated virus vaccine was not capable of eliciting detectable NA-specific antibody, even in the presence of adjuvants previously shown to increase total virus-specific IgG. However, both naïve and vaccinated newborns generated a neuraminidase-specific antibody response following virus infection. Interestingly, the presence of the vaccine-induced response did not prevent generation of systemic antibody to neuraminidase following challenge, although the respiratory response was reduced in a significant portion of newborns. These findings are the first, to our knowledge, to evaluate the newborn response to the influenza neuraminidase protein as well as the impact of previous vaccination on generation of these antibodies following virus infection.
Patrick K. Shultz, Kali F. Crofts, Beth C. Holbrook, Martha A. Alexander-Miller
In this work, we have explored natural unmodified low- and high-density lipoproteins (LDL and HDL) as selective delivery vectors in colorectal cancer therapy. We show in vitro in cultured cells and in vivo (NanoSPECT/CT) in the CT-26 mice colorectal cancer model that LDLs are mainly taken up by cancer cells, while HDLs are preferentially taken up by macrophages. We loaded LDLs with cisplatin and HDLs with the heat shock protein-70 inhibitor AC1LINNC, turning them into a pair of “Trojan horses” delivering drugs selectively to their target cells as demonstrated in vitro in human colorectal cancer cells and macrophages, and in vivo. Coupling of the drugs to lipoproteins and stability was assessed by mass and raman spectrometry analysis. Cisplatin vectorized in LDLs led to better tumor growth suppression with strongly reduced adverse effects such as a renal or liver toxicity. AC1LINNC vectorized into HDLs induced a strong oxidative burst in macrophages and innate anti-cancer immune response. Cumulative anti-tumor effect was observed for both drug-loaded lipoproteins. Altogether, our data show that lipoproteins from patient’s blood can be used as natural nanocarriers allowing cell specific targeting, paving the way toward more efficient, safer and personalized use of chemo-and immunotherapeutic drugs in cancer.
Tarik Hadi, Christophe Ramseyer, Thomas Gautier, Pierre-Simon Bellaye, Tatiana Lopez, Antonin Schmitt, Foley Sarah, Semen Yesylevskyy, Thibault Minervini, Romain Douhard, Lucile Dondaine, Lil Proukhnitzky, Samir Messaoudi, Maeva Wendremaire, Mathieu Moreau, Fabrice Neiers, Bertrand Collin, Franck Denat, Laurent Lagrost, Carmen Garrido, Frederic Lirussi
Inflammatory damage contributes to β-cell failure in type 1 and 2 diabetes (T1D and T2D). Mitochondria are damaged by inflammatory signaling in β-cells, resulting in impaired bioenergetics and initiation of pro-apoptotic machinery. Hence, the identification of protective responses to inflammation could lead to new therapeutic targets. Here we report that mitophagy serves as a protective response to inflammatory stress in both human and rodent β-cells. Utilizing in vivo mitophagy reporters, we observed that diabetogenic pro-inflammatory cytokines induced mitophagy in response to nitrosative/oxidative mitochondrial damage. Mitophagy-deficient β-cells were sensitized to inflammatory stress, leading to the accumulation of fragmented dysfunctional mitochondria, increased β-cell death, and hyperglycemia. Overexpression of CLEC16A, a T1D gene and mitophagy regulator whose expression in islets is protective against T1D, ameliorated cytokine-induced human β-cell apoptosis. Thus, mitophagy promotes β-cell survival and prevents diabetes by countering inflammatory injury. Targeting this pathway has the potential to prevent β-cell failure in diabetes and may be beneficial in other inflammatory conditions.
Vaibhav Sidarala, Gemma L. Pearson, Vishal S. Parekh, Benjamin Thompson, Lisa Christen, Morgan A. Gingerich, Jie Zhu, Tracy Stromer, Jianhua Ren, Emma C. Reck, Biaoxin Chai, John A. Corbett, Thomas Mandrup-Poulsen, Leslie S. Satin, Scott A. Soleimanpour
No posts were found with this tag.