Inhibition of Class I Histone Deacetylase Activity Blocks the Induction of TNFAIP3 Both Directly and Indirectly via the Suppression of Endogenous TNF-α

Histone deacetylase inhibitors (HDIs) are promising drugs for the treatment of inflammatory diseases. However, their therapeutical exploitation is slowed down by severe adverse manifestations that can hardly be foreseen, mainly due to incomplete knowledge of how HDIs impact the delicate balance of inflammatory mediators. In this work, we characterized the effects of the HDI trichostatin A (TSA) on the expression of TNFAIP3, which is a crucial inhibitor of the classical NF-kB pathway and an LPS-induced negative feedback regulator. The accumulation of TNFAIP3 mRNA after LPS stimulation showed biphasic behavior, with one wave within the first hour of stimulation and a second wave several hours later, which were both reduced by TSA. By using inhibition and knockdown approaches, we identified two temporally and mechanistically distinct modes of action. The first wave of TNAIP3 accumulation was directly blunted by the histone deacetylase (HDAC) blockade. By contrast, the second wave was decreased mainly because of the lack of endogenous TNF-α induction, which, in turn, depended on the intact HDAC activity. In both cases, class I HDACs appeared to play a nonredundant role, with HDAC3 required, but not sufficient, for TNF-α and TNFAIP3 induction. In addition to TNFAIP3, TNF-α is known to induce many response genes that orchestrate the inflammatory cascade. Thus, suppression of TNF-α may represent a general mechanism through which HDIs regulate a selected set of target genes

The PDE4 Inhibitor Tanimilast Restrains the Tissue-Damaging Properties of Human Neutrophils

: Neutrophils, the most abundant subset of leukocytes in the blood, play a pivotal role in host response against invading pathogens. However, in respiratory diseases, excessive infiltration and activation of neutrophils can lead to tissue damage. Tanimilast-international non-proprietary name of CHF6001-is a novel inhaled phosphodiesterase 4 (PDE4) inhibitor in advanced clinical development for the treatment of chronic obstructive pulmonary disease (COPD), a chronic inflammatory lung disease where neutrophilic inflammation plays a key pathological role. Human neutrophils from healthy donors were exposed to pro-inflammatory stimuli in the presence or absence of tanimilast and budesonide-a typical inhaled corticosteroid drug-to investigate the modulation of effector functions including adherence to endothelial cells, granule protein exocytosis, release of extracellular DNA traps, cytokine secretion, and cell survival. Tanimilast significantly decreased neutrophil-endothelium adhesion, degranulation, extracellular DNA traps casting, and cytokine secretion. In contrast, it promoted neutrophil survival by decreasing both spontaneous apoptosis and cell death in the presence of pro-survival factors. The present work suggests that tanimilast can alleviate the severe tissue damage caused by massive recruitment and activation of neutrophils in inflammatory diseases such as COPD

Insights into isoform-specific mineralocorticoid receptor action in the hippocampus

The mineralocorticoid receptor (MR) plays a critical role in the mammalian brain as a mediator of appropriate cellular and behavioural responses under both baseline and stressful conditions. In the hippocampus, the MR has been implicated in several processes, such as neuronal maintenance, adult neurogenesis, inhibitory control of the hypothalamic-pituitary-adrenal axis, and learning and memory. Because of its high affinity for endogenous glucocorticoid hormones, the MR has long been postulated to mediate tonic actions in the brain, but more recent data have expanded on this view, indicating that the MR elicits dynamic responses as well. The complexity of the diverse molecular, cellular, and physiological functions fulfilled by the human, rat and mouse MR could at least partially be explained by the existence of different isoforms of the receptor. The structural and functional characteristics of these isoforms, however, have remained largely unexplored. The present article will review the current knowledge concerning human, rat, and mouse MR isoforms and evaluate seminal studies concerning the roles of the brain MR, with the intent to shed light on the function of its specific isoforms.</p

The PDE4 inhibitor tanimilast shows distinct immunomodulatory properties associated with a type 2 endotype and CD141 upregulation

Tanimilast is a novel and selective inhaled inhibitor of phosphodiesterase-4 in advanced clinical development for chronic obstructive pulmonary disease (COPD). Tanimilast is known to exert prominent anti-inflammatory activity when tested in preclinical experimental models as well as in human clinical studies. Recently, we have demonstrated that it also finely tunes, rather than suppressing, the cytokine network secreted by activated dendritic cells (DCs). This study was designed to characterize the effects of tanimilast on T-cell polarizing properties of DCs and to investigate additional functional and phenotypical features induced by tanimilast

Introduction of direct oral anticoagulant within 7\ua0days of stroke onset: a nomogram to predict the probability of 3-month modified Rankin Scale score\u2009>\ua02

In clinical practice, direct oral anticoagulants (DOACs) are often started earlier ( 64\u20097\ua0days) than in randomized clinical trials after stroke. We aimed to develop a nomogram model incorporating time of DOAC introduction\u2009 64\u20097\ua0days of stroke onset in combination with different degrees of stroke radiological/neurological severity at the time of treatment to predict the probability of unfavorable outcome. We conducted a multicenter prospective study including 344 patients who started DOAC 1-7\ua0days after atrial fibrillation-related stroke onset. Computed tomography scan 24-36\ua0h after stroke onset was performed in all patients before starting DOAC. Unfavorable outcome was defined as modified Rankin Scale (mRS) score\u2009>\u20092\ua0at 3\ua0months. Based on multivariate logistic model, the nomogram was generated. We assessed the discriminative performance by using the area under the receiver operating characteristic curve (AUC-ROC) and calibration of risk prediction model by using the Hosmer-Lemeshow test. Onset-to-treatment time for DOAC (OR: 1.21, p\u2009=\u20090.030), NIH Stroke Scale (NIHSS) score at the time of treatment (OR: 1.00 for NIHSS\u2009=\u20090-5; OR: 2.67, p\u2009=\u20090.016 for NIHSS\u2009=\u20096-9; OR: 26.70, p\u2009<\u20090.001 for NIHSS\u2009=\u200910-14; OR: 57.48, p\u2009<\u20090.001 for NIHSS\u2009 65\u200915), size infarct (OR: 1.00 for small infarct; OR: 2.26, p\u2009=\u20090.023 for medium infarct; OR: 3.40, p\u2009=\u20090.005 for large infarct), and age\u2009 65\u200980\ua0years (OR: 1.96, p\u2009=\u20090.028) remained independent predictors of unfavorable outcome to compose the nomogram. The AUC-ROC of nomogram was 0.858. Calibration was good (p\u2009=\u20092.889 for the Hosmer-Lemeshow test). The combination of onset-to-treatment time of DOAC with stroke radiological/neurological severity at the time of treatment and old age may predict the probability of unfavorable outcome

SARS-CoV-2–associated ssRNAs activate inflammation and immunity via TLR7/8

The inflammatory and IFN pathways of innate immunity play a key role in the resistance and pathogenesis of coronavirus disease 2019 (COVID-19). Innate sensors and SARS-CoV-2–associated molecular patterns (SAMPs) remain to be completely defined. Here, we identified single-stranded RNA (ssRNA) fragments from the SARS-CoV-2 genome as direct activators of endosomal TLR7/8 and MyD88 pathway. The same sequences induced human DC activation in terms of phenotype and function, such as IFN and cytokine production and Th1 polarization. A bioinformatic scan of the viral genome identified several hundreds of fragments potentially activating TLR7/8, suggesting that products of virus endosomal processing potently activate the IFN and inflammatory responses downstream of these receptors. In vivo, SAMPs induced MyD88-dependent lung inflammation characterized by accumulation of proinflammatory and cytotoxic mediators and immune cell infiltration, as well as splenic DC phenotypical maturation. These results identified TLR7/8 as a crucial cellular sensor of ssRNAs encoded by SARS-CoV-2 involved in host resistance and the disease pathogenesis of COVID-19

SARS-CoV-2-associated ssRNAs activate inflammation and immunity via TLR7/8

The inflammatory and IFN pathways of innate immunity play a key role in both resistance and pathogenesis of Coronavirus Disease 2019 (COVID-19). Innate sensors and SARS-CoV-2-Associated Molecular Patterns (SAMPs) remain to be completely defined. Here we identify single-stranded RNA (ssRNA) fragments from SARS-CoV-2 genome as direct activators of endosomal TLR7/8 and MyD88 pathway. The same sequences induced human DC activation in terms of phenotype and functions, such as IFN and cytokine production and Th1 polarization. A bioinformatic scan of the viral genome identified several hundreds of fragments potentially activating TLR7/8, suggesting that products of virus endosomal processing potently activate the IFN and inflammatory responses downstream these receptors. In vivo, SAMPs induced MyD88-dependent lung inflammation characterized by accumulation of proinflammatory and cytotoxic mediators and immune cell infiltration, as well as splenic DC phenotypical maturation. These results identify TLR7/8 as crucial cellular sensors of ssRNAs encoded by SARS-CoV-2 involved in host resistance and disease pathogenesis of COVID-19