Acute respiratory distress syndrome (ARDS), the most severe form of acute lung injury, is associated with reduced lung compliance and hypoxemia. Curcumin exhibits potent anti-inflammatory properties but has poor solubility and rapid plasma clearance. To overcome these physiochemical limitations and uncover the full therapeutic potential of curcumin in lung inflammation, in this study we utilized a novel water-soluble curcumin formulation (CDC) and delivered it directly into the lungs of C57BL/6 mice inoculated with a lethal dose of Klebsiella pneumoniae (KP). Administration of CDC led to a significant reduction in mortality, in bacterial presence within blood and lungs, as well as in lung injury, inflammation, and oxidative stress. The expression of Klebsiella hemolysin gene; TNF-a; IFN-b; nucleotide-binding domain, leucine-rich-containing family, pyrin domaincontaining-3; hypoxia-inducible factor 1/2a; and NF-kB were also decreased following CDC treatment, suggesting modulation of the inflammasome complex and hypoxia signaling pathways as an underlying mechanism by which CDC reduces the severity of pneumonia. On a cellular level, CDC led to diminished cell death, improved viability, and protection of human lung epithelial cells in vitro. Overall, our studies demonstrate that CDC administration improves cell survival and reduces injury, inflammation, and mortality in a murine model of lethal gram-negative pneumonia. CDC, therefore, has promising anti-inflammatory potential in pneumonia and likely other inflammatory lung diseases, demonstrating the importance of optimizing the physicochemical properties of active natural products to optimize their clinical application.

Objectives Lung contusion (LC) is a major risk factor for the development of acute respiratory distress syndrome (ARDS). We set to determine the role of TLR3 and the binding of dsRNA in the pathogenesis of sterile injury following lung contusion. Methods TLR3 expression was analyzed in post-mortem lung samples from patients with LC. Unilateral LC was induced in TLR3 (−/−), TRIF (−/−), and WT mice; subsequently, lung injury and inflammation were evaluated. Apoptotic indices, phagocytic activity and phenotypic characterization of the macrophages were determined. Double stranded (ds) RNA in BAL and serum samples following LC were measured. A TLR3/dsRNA ligand inhibitor was injected into WT mice prior to LC. Measurements and Main Results TLR3 expression was higher in patients and WT mice with LC. The degree of lung injury, inflammation, and macrophage apoptosis was reduced in TLR3 (−/−), TRIF (−/−), and WT mice with TLR3 antibody neutralization. Alveolar macrophages from TLR3 (−/−) mice had a lower early apoptotic index, a predominant M2 phenotype and increased surface translocation of TLR3 from the endosome to the surface. When compared to viral activation pathways, lung injury in LC demonstrated increased p38 MAPK, ERK1/2 phosphorylation with inflammasome activation without a corresponding increase in NF-kB or Type-1 Interferon production. Additionally, pretreatment with TLR3/dsRNA ligand inhibitor led to a reduction in injury, inflammation, and macrophage apoptosis. Conclusions We conclude that the interaction of dsRNA from injured cells with TLR3 drives the acute inflammatory response following LC.

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Objective To understand the fate and regulation of hypoxic type II alveolar epithelial cells (AECs) after lung contusion (LC). Background LC due to thoracic trauma is a major risk factor for the development of acute respiratory distress syndrome. AECs have recently been implicated as a primary driver of inflammation in LC. The main pathological consequence of LC is hypoxia, and a key mediator of adaptation to hypoxia is hypoxia-inducible factor (HIF)-1. We have recently published that HIF-1α is a major driver of acute inflammation after LC through type II AEC. Methods LC was induced in wild-type mice (C57BL/6), luciferase-based hypoxia reporter mice (ODD-Luc), and HIF-1α conditional knockout mice. The degree of hypoxia was assessed using hypoxyprobe and in vivo imaging system. The fate of hypoxic AEC was evaluated by luciferase dual staining with caspases-3 and Ki-67, terminal deoxynucleotidyl transferase dUTP nick end labeling, and flow cytometry with ApoStat. NLRP-3 expression was determined by western blot. Laser capture microdissection was used to isolate AECs in vivo, and collected RNA was analyzed by Q-PCR for HIF-related pathways. Results Global hypoxia was present after LC, but hypoxic foci were not uniform. Hypoxic AECs preferentially undergo apoptosis. There were significant reductions in NLRP-3 in HIF-1α conditional knockout mice. The expression of proteins involved in HIF-related pathways and inflammasome activation were significantly increased in hypoxic AECs. Conclusions These are the first in vivo data to identify, isolate, and characterize hypoxic AECs. HIF-1α regulation through hypoxic AECs is critical to the initiation of acute inflammation after LC.

Malaria, the disease caused by Plasmodium parasites, remains a major global health burden. The liver stage of Plasmodium falciparum infection is a leading target for immunological and pharmacological interventions. Therefore, novel approaches providing specific detection and isolation of live P. falciparum exoerythrocytic forms (EEFs) are warranted. Utilizing a recently generated parasite strain expressing green fluorescent protein (GFP) we established a method which, allows for detection and isolation of developing live P. falciparum liver stages by flow cytometry. Using this technique we compared the susceptibility of five immortalized human hepatocyte cell lines and primary hepatocyte cultures from three donors to infection by P. falciparum sporozoites. Here, we show that EEFs can be detected and isolated from in vitro infected cultures of the HC-04 cell line and primary human hepatocytes. We confirmed the presence of developing parasites in sorted live human hepatocytes and characterized their morphology by fluorescence microscopy. Finally, we validated the practical applications of our approach by re-examining the importance of host ligand CD81 for hepatocyte infection by P. falciparum sporozoites in vitro and assessment of the inhibitory activity of anti-sporozoite antibodies. This methodology provides us with the tools to study both, the basic biology of the P. falciparum liver stage and the effects of host-derived factors on the development of P. falciparum EEFs.

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BACKGROUND AND PURPOSERilpivirine and etravirine are second-generation non-nucleoside reverse transcriptase inhibitors (NNRTIs) indicated for the treatment of HIV/AIDS. The constitutive androstane receptor (CAR) regulates the expression of genes involved in various biological processes, including the transport and biotransformation of drugs. We investigated the effect of rilpivirine and etravirine on the activity of the wild-type human CAR (hCAR-WT) and its hCAR-SV23 and hCAR-SV24 splice variants, and compared it with first-generation NNRTIs (efavirenz, nevirapine, and delavirdine). EXPERIMENTAL APPROACHReceptor activation, ligand-binding domain (LBD) transactivation, and co-activator recruitment were investigated in transiently transfected, NNRTI-treated HepG2 cells. Nuclear translocation of green fluorescent protein-tagged hCAR-WT and CYP2B6 gene expression were assessed in NNRTI-treated human hepatocytes. KEY RESULTSRilpivirine and etravirine activated hCAR-WT, but not hCAR-SV23 or hCAR-SV24, and without transactivating the LBD or recruiting steroid receptor coactivators SRC-1, SRC-2, or SRC-3. Among the first-generation NNRTIs investigated, only efavirenz activated hCAR-WT, hCAR-SV23, and hCAR-SV24, but none of them transactivated the LBD of these receptors or substantively recruited SRC-1, SRC-2, or SRC-3. Rilpivirine, etravirine, and efavirenz triggered nuclear translocation of hCAR-WT and increased hCAR target gene (CYP2B6) expression. CONCLUSION AND IMPLICATIONSNNRTIs activate hCAR-WT, hCAR-SV23, and hCAR-SV24 in a drug-specific and isoform-selective manner. The activation occurs by a mechanism that does not appear to involve binding to the LBD or recruitment of SRC-1, SRC-2, or SRC-3. AbbreviationsCAR, constitutive androstane receptor; CAS, Chemical Abstracts Service; CITCO, 6-(4-chlorophenyl)imidazo [2,1-b] [1,3]

ObjectiveAutoantibodies recognizing specificity protein 4 (Sp4) were recently discovered in adults with idiopathic inflammatory myopathies (IIM). Anti‐Sp4 autoantibodies co‐occurred in patients with anti–transcription intermediary factor 1 (anti‐TIF1) autoantibody‐positive dermatomyositis (DM) and were associated with a reduced risk of cancer. In the present study, the prevalence and clinical features associated with anti‐Sp4 autoantibodies in juvenile‐onset IIM were investigated.MethodsSerum samples from 336 patients with juvenile myositis in a cross‐sectional cohort and 91 healthy controls were screened for anti‐Sp4 autoantibodies using enzyme‐linked immunosorbent assay. Clinical characteristics, outcomes, and HLA alleles of those with and those without anti‐Sp4 autoantibodies were compared.ResultsAnti‐Sp4 autoantibodies were present in 23 patients (7%) with juvenile myositis and were not present in any of the controls. Anti‐Sp4 autoantibodies were found among each clinical myositis subgroup. The frequency of TIF1 autoantibody positivity was significantly higher among those with anti‐Sp4 autoantibodies (21 [91%] versus 92 [30%], P < 0.001). In the anti‐TIF1 autoantibody–positive subgroup, Raynaud's phenomenon (8 [38%] versus 2 [2%], P < 0.001) was more common and peak aspartate aminotransferase was significantly lower in those with anti‐Sp4 autoantibodies. None of the patients with anti‐Sp4 autoantibodies required a wheelchair. Among White patients, DQA1*04 and DRB1*08 were associated with anti‐Sp4 autoantibodies.ConclusionAnti‐Sp4 autoantibodies were found in patients with juvenile‐onset IIM, predominantly those with coexisting anti‐TIF1 autoantibodies. Patients with anti‐Sp4 autoantibodies represent a phenotypic subset of anti‐TIF1 autoantibody–positive myositis characterized by frequent Raynaud's phenomenon and less pronounced muscle involvement, similar to adults with these autoantibodies. Novel immunogenetic risk factors for White patients with IIM were identified among juveniles with anti‐Sp4 autoantibodies.