Piezo1 channels restrain ILC2s and regulate the development of airway hyperreactivity

Mechanosensitive ion channels sense force and pressure in immune cells to drive the inflammatory response in highly mechanical organs. Here, we report that Piezo1 channels repress group 2 innate lymphoid cell (ILC2)-driven type 2 inflammation in the lungs. Piezo1 is induced on lung ILC2s upon activation, as genetic ablation of Piezo1 in ILC2s increases their function and exacerbates the development of airway hyperreactivity (AHR). Conversely, Piezo1 agonist Yoda1 reduces ILC2-driven lung inflammation. Mechanistically, Yoda1 inhibits ILC2 cytokine secretion and proliferation in a KLF2-dependent manner, as we found that Piezo1 engagement reduces ILC2 oxidative metabolism. Consequently, in vivo Yoda1 treatment reduces the development of AHR in experimental models of ILC2-driven allergic asthma. Human-circulating ILC2s express and induce Piezo1 upon activation, as Yoda1 treatment of humanized mice reduces human ILC2-driven AHR. Our studies define Piezo1 as a critical regulator of ILC2s, and we propose the potential of Piezo1 activation as a novel therapeutic approach for the treatment of ILC2-driven allergic asthma.

LAIR-1 limits macrophage activation in acute inflammatory lung injury

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are serious health problems that manifest as acute respiratory failure in response to different conditions, including viral respiratory infections. Recently, the inhibitory properties of leukocyte-associated immunoglobulin-like receptor-1 (LAIR-1) were demonstrated in allergic and viral airway inflammation. In this study, we investigate the implication of LAIR-1 in ALI/ARDS and explore the underlying mechanisms. Polyinosinic:polycytidylic acid, a synthetic analog of double-stranded RNA, was used to mimic acute inflammation in viral infections. We demonstrate that LAIR-1 is predominantly expressed on macrophages and regulates their recruitment to the lungs as well as their activation in response to polyinosinic:polycytidylic acid. Interestingly, LAIR-1 deficiency increases neutrophil recruitment as well as lung resistance and permeability. In particular, we highlight the capacity of LAIR-1 to regulate the secretion of CXCL10, considered a key marker of macrophage overactivation in acute lung inflammation. We also reveal in COVID-19-induced lung inflammation that LAIR1 is upregulated on lung macrophages in correlation with relevant immune regulatory genes. Altogether, our findings demonstrate the implication of LAIR-1 in the pathogenesis of ALI/ARDS by means of the regulation of macrophages, thereby providing the basis of a novel therapeutic target.

Enhancing autophagy in CD11c+ antigen-presenting cells as a therapeutic strategy for acute respiratory distress syndrome

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are severe clinical disorders that mainly develop from viral respiratory infections, sepsis, and chest injury. Antigen-presenting cells play a pivotal role in propagating uncontrolled inflammation and injury through the excess secretion of pro-inflammatory cytokines and recruitment of immune cells. Autophagy, a homeostatic process that involves the degradation of cellular components, is involved in many processes including lung inflammation. Here, we use a polyinosinic-polycytidylic acid (poly(I:C))-induced lung injury mouse model to mimic viral-induced ALI/ARDS and show that disruption of autophagy in macrophages exacerbates lung inflammation and injury, whereas autophagy induction attenuates this process. Therefore, induction of autophagy in macrophages can be a promising therapeutic strategy in ALI/ARDS.

Human PD-1 agonist treatment alleviates neutrophilic asthma by reprogramming T cells

BACKGROUND

Neutrophilic asthma is associated with disease severity and corticosteroid insensitivity. Novel therapies are required to manage this life-threatening asthma phenotype. Programmed cell death protein-1 (PD-1) is a key homeostatic modulator of the immune response for T-cell effector functions.

OBJECTIVE

We sought to investigate the role of PD-1 in the regulation of acute neutrophilic inflammation in a murine model of airway hyperreactivity (AHR).

METHODS

House dust mite was used to induce and compare neutrophilic AHR in wild-type and PD-1 knockout mice. Then, the therapeutic potential of a human PD-1 agonist was tested in a humanized mouse model in which the PD-1 extracellular domain is entirely humanized. Single-cell RNA sequencing and flow cytometry were mainly used to investigate molecular and cellular mechanisms.

RESULTS

PD-1 was highly induced on pulmonary T cells in our inflammatory model. PD-1 deficiency was associated with an increased neutrophilic AHR and high recruitment of inflammatory cells to the lungs. Consistently, PD-1 agonist treatment dampened AHR, decreased neutrophil recruitment, and modulated cytokine production in a humanized PD-1 mouse model. Mechanistically, we demonstrated at the transcriptional and protein levels that the inhibitory effect of PD-1 agonist is associated with the reprogramming of pulmonary effector T cells that showed decreased number and activation.

CONCLUSIONS

PD-1 agonist treatment is efficient in dampening neutrophilic AHR and lung inflammation in a preclinical humanized mouse model.

Impact of the COVID-19 pandemic on maternal mental health during pregnancy: The CONCEPTION study – Phase I

Introduction

Mental health regional differences during pregnancy through the COVID-19 pandemic is understudied.

Objectives

We aimed to quantify the impact of the COVID-19 pandemic on maternal mental health during pregnancy.

Methods

A cohort study with a web-based recruitment strategy and electronic data collection was initiated in 06/2020. Although Canadian women, >18 years were primarily targeted, pregnant women worldwide were eligible. The current analysis includes data on women enrolled 06/2020-11/2020. Self-reported data included mental health measures (Edinburgh Perinatal Depression Scale (EPDS), Generalized Anxiety Disorders (GAD-7)), stress. We compared maternal mental health stratifying on country/continents of residence, and identified determinants of mental health using multivariable regression models.

Results

Of 2,109 pregnant women recruited, 1,932 were from Canada, 48 the United States (US), 73 Europe, 35 Africa, and 21 Asia/Oceania. Mean depressive symptom scores were lower in Canada (EPDS 8.2, SD 5.2) compared to the US (EPDS 10.5, SD 4.8) and Europe (EPDS 10.4, SD 6.5) (p<0.05), regardless of being infected or not. Maternal anxiety, stress, decreased income and access to health care due to the pandemic were increasing maternal depression. The prevalence of severe anxiety was similar across country/continents. Maternal depression, stress, and earlier recruitment during the pandemic (June/July) were associated with increased maternal anxiety.

Conclusions

In this first international study on the impact of the COVID-19 pandemic, CONCEPTION has shown significant country/continent-specific variations in depressive symptoms during pregnancy, whereas severe anxiety was similar regardless of place of residence. Strategies are needed to reduce COVID-19’s mental health burden in pregnancy.

Disclosure

No significant relationships.

CB2 engagement enhances group 2 innate lymphoid cell expansion and induction of airway hyperreactivity

Cannabinoids modulate the activation of immune cells and physiological processes in the lungs. Group 2 innate lymphoid cells (ILC2)s are central players in type-2 asthma, but how cannabinoids modulate ILC2 activation remains to be elucidated. Using a combination of cannabinoid receptor (CB)2 KO mice, a CB2 antagonist and agonist, we here provide evidence that CB2 signaling in ILC2s is important for the development of ILC2-driven airway inflammation in both mice and human. We show that both naïve and activated murine pulmonary ILC2s express CB2. CB2 signaling did not affect ILC2 homeostasis at steady state, but strikingly stimulated ILC2 proliferation and function upon activation using various models of airway inflammation including IL-33, IL-25 and Alternaria alternata. As a result, ILC2s lacking CB2 induced lower lung inflammation, as we made similar observations using a CB2 antagonist. Conversely, CB2 agonism remarkably exacerbated ILC2-driven airway hyperreactivity and lung inflammation. Mechanistically, transcriptomic and protein analysis revealed that CB2 signaling induced CREB phosphorylation in ILC2s. Human ILC2s expressed CB2, as CB2 antagonism and agonism showed opposing effects on ILC2 effector function and development of airway hyperreactivity in humanized mice. Collectively, our results define CB2 signaling in ILC2s as an important modulator of airway inflammation. Furthermore, our findings highlight the stimulatory capacity of cannabinoids on ILC2s and offer new therapeutic avenues, including the use of substances or pathways able to modulate CB2 and capable of alleviating lung function in patients with lung inflammation.

Cannabinoid receptor 2 engagement promotes group 2 innate lymphoid cell expansion and enhances airway hyperreactivity

BACKGROUND

Cannabinoids modulate the activation of immune cells and physiologic processes in the lungs. Group 2 innate lymphoid cells (ILC2s) are central players in type 2 asthma, but how cannabinoids modulate ILC2 activation remains to be elucidated.

OBJECTIVE

Our goal was to investigate the effects of cannabinoids on ILC2s and their role in asthma.

METHODS

A combination of cannabinoid receptor (CB)2 knockout (KO) mice, CB2 antagonist and agonist were used in the mouse models of IL-33, IL-25, and Alternaria alternata ILC2-dependent airway inflammation. RNA sequencing was performed to assess transcriptomic changes in ILC2s, and humanized mice were used to assess the role of CB2 signaling in human ILC2s.

RESULTS

We provide evidence that CB2 signaling in ILC2s is important for the development of ILC2-driven airway inflammation in both mice and human. We showed that both naive and activated murine pulmonary ILC2s express CB2. CB2 signaling did not affect ILC2 homeostasis at steady state, but strikingly it stimulated ILC2 proliferation and function upon activation. As a result, ILC2s lacking CB2 induced lower lung inflammation, as we made similar observations using a CB2 antagonist. Conversely, CB2 agonism remarkably exacerbated ILC2-driven airway hyperreactivity and lung inflammation. Mechanistically, transcriptomic and protein analysis revealed that CB2 signaling induced cyclic adenosine monophosphate-response element binding protein (CREB) phosphorylation in ILC2s. Human ILC2s expressed CB2, as CB2 antagonism and agonism showed opposing effects on ILC2 effector function and development of airway hyperreactivity in humanized mice.

CONCLUSION

Collectively, our results define CB2 signaling in ILC2s as an important modulator of airway inflammation.

PD-1 inhibition on pulmonary ILC2s promotes TNF-α production and restricts progression of metastatic melanoma tumor growth

Pulmonary metastatic melanoma is an aggressive form of cancer that is highly resistant to treatment and research efforts targeting this cancer are severely lacking. While pulmonary Group 2 Innate lymphoid cells (ILC2s) represent one of the major tissue-resident innate lymphoid cell populations at steady state and are key drivers of cytokine secretion in their occupational niche, their role in pulmonary cancer progression remains unclear. As the programmed cell death protein-1 (PD-1) plays a major role in cancer immunotherapy and immunoregulatory properties, here we investigated the specific effect of PD-1 inhibition on ILC2s during a pulmonary murine model of melanoma cancer metastasis. We demonstrate that murine models of B16 tumor growth upregulate PD-1 expression on pulmonary ILC2s and that this expression severely promotes tumor growth. Conversely, utilizing targeted murine adoptive transfers we demonstrate that PD-1 inhibition on ILC2s specifically and significantly inhibits tumor growth. Furthermore, the results revealed that PD-1 inhibition upregulated both murine and human ILC2 TNF-α production and secretion, a cytotoxic cytokine that we demonstrate has the ability to directly induce tumor cell death and apoptosis independent of adaptive immunity. Together, the results of these studies may lead to a better understanding of ILC2s and their role in metastatic melanoma, as well as providing a foundation for further elucidation of their anti-tumor mechanisms in cancer progression.

Supported by grants from NIH (R01 ES025786, R01 ES021801, R01 HL144790, R01 HL151493, R01 AI145813 and R01 HL151769)

LAIR-1 acts as an immune checkpoint on activated ILC2s and regulates the induction of airway hyperreactivity

BACKGROUND

Type 2 innate lymphoid cells (ILC2s) are relevant players in type 2 asthma. They initiate eosinophil infiltration and airway hyperreactivity (AHR) through cytokine secretion. Leukocyte-associated immunoglobulin-like receptor 1 (LAIR-1) is an inhibitory receptor considered to be an immune checkpoint in different inflammatory diseases.

OBJECTIVE

Our aim here was to investigate the expression of LAIR-1 and assess its role in human and murine ILC2s.

METHODS

Wild-type and LAIR-1 knockout mice were intranasally challenged with IL-33, and pulmonary ILC2s were sorted to perform an ex vivo comparative study based on RNA sequencing and flow cytometry. We next studied the impact of LAIR-1 deficiency on AHR and lung inflammation by using knockout mice and adoptive transfer experiments in Rag2-/-Il2rg-/- mice. Knockdown antisense strategies and humanized mice were used to assess the role of LAIR-1 in human ILC2s.

RESULTS

We have demonstrated that LAIR-1 is inducible on activated ILC2s and downregulates cytokine secretion and effector function. LAIR-1 signaling in ILC2s was mediated via inhibitory pathways, including SHP1/PI3K/AKT, and LAIR-1 deficiency led to exacerbated ILC2-dependent AHR in IL-33 and Alternaria alternata models. In adoptive transfer experiments, we confirmed the LAIR-1-mediated regulation of ILC2s in vivo. Interestingly, LAIR-1 was expressed and inducible in human ILC2s, and knockdown approaches of Lair1 resulted in higher cytokine production. Finally, engagement of LAIR-1 by physiologic ligand C1q significantly reduced ILC2-dependent AHR in a humanized ILC2 murine model.

CONCLUSION

Our results unravel a novel regulatory axis in ILC2s with the capacity to reduce allergic AHR and lung inflammation.

HAND HYGIENE COMPLIANCE IN THE PREVENTION OF HOSPITAL ACQUIRED INFECTIONS: A SYSTEMATIC REVIEW

BACKGROUND

Healthcare worker's (HCW) hands are known to be a primary source of transmission of hospital-acquired infections (HAIs). Thus, practicing hand hygiene (HH) and adhering to HH guidelines are both expected to decrease the risk of transmission but there is no consensus on the optimal hand hygiene compliance (HHC) rate that HCWs should aim for.

AIM

The objective of this study was to systematically review the published literature to determine an optimal threshold of HCW HHC rate associated with the lowest incidence rate of HAIs.

METHODS

This systematic review was performed according to the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines. We searched online databases using a comprehensive search criterion for randomized controlled trials and non-randomized controlled studies, investigating the impact of HCW's HHC rate on HAI rates in patients of all ages, within healthcare facilities in high income countries.

FINDINGS

Of the 8,093 articles citations and abstracts screened, 35 articles were included in the review. Most studies reported overall HAIs per 1000 patient-days and device-associated HAIs per 1000 device-days. Most studies reported HHC rates between 60%-70%. Lower incidence HAI rates seemed to be achieved with HHC rates of approximately 60%. Studies included were not originally designed to assess the impact of HHC on HAI rates but risk of bias was assessed as per our predetermined exposure and outcome criterion. 11 (31%) of studies were deemed at low risk of bias.

CONCLUSIONS

Although HHC is part of HCW's code of conduct, very high HHC rates were difficult to reach. In observational studies, HHC and HAI followed a negative relationship up to about 60%. Due to flaws in study design, causality could not be inferred; only general trends could be discussed. Given the limitations, there is a need for high-quality evidence to support the implementation of specified targets of HHC rates.

PD-1 Blockade on Tumor Microenvironment-Resident ILC2s Promotes TNF-α Production and Restricts Progression of Metastatic Melanoma

While pulmonary ILC2s represent one of the major tissue-resident innate lymphoid cell populations at steady state and are key drivers of cytokine secretion in their occupational niche, their role in pulmonary cancer progression remains unclear. As the programmed cell death protein-1 (PD-1) plays a major role in cancer immunotherapy and immunoregulatory properties, here we investigate the specific effect of PD-1 inhibition on ILC2s during pulmonary B16 melanoma cancer metastasis. We demonstrate that PD-1 inhibition on ILC2s suppresses B16 tumor growth. Further, PD-1 inhibition upregulates pulmonary ILC2-derived TNF-α production, a cytotoxic cytokine that directly induces cell death in B16 cells, independent of adaptive immunity. Together, these results highlight the importance of ILC2s and their anti-tumor role in pulmonary B16 cancer progression during PD-1 inhibitory immunotherapy.

MDM2 induces EMT via the B‑Raf signaling pathway through 14‑3‑3

MDM2 proto-oncogene, E3 ubiquitin protein ligase (MDM2) is a well-known oncogene and has been reported to be closely associated with epithelial-to-mesenchymal transition (EMT). The present study first demonstrated that the expression levels of MDM2 were markedly increased in TGF-β-induced EMT using quantitative PCR and western blotting. In addition, MDM2 was demonstrated to be associated with pathological grade in clinical glioma samples by immunohistochemical staining. Furthermore, overexpression of MDM2 promoted EMT in glioma, lung cancer and breast cancer cell lines using a scratch wound migration assay. Subsequently, the present study explored the mechanism by which MDM2 promoted EMT and revealed that MDM2 induced EMT by upregulating EMT-related transcription factors via activation of the B-Raf signaling pathway through tyrosine 3-monooxygenase activation protein ε using RNA sequencing and western blotting. This mechanism depended on the p53 gene. Furthermore, in vivo experiments and the colony formation experiment demonstrated that MDM2 could promote tumor progression and induce EMT via the B-Raf signaling pathway. Since EMT contributes to increased drug resistance in tumor cells, the present study also explored the relationship between MDM2 and drug sensitivity using an MTT assay, and identified that MDM2 promoted cell insensitivity to silibinin treatment in an EMT-dependent manner. This finding is crucial for the development of cancer therapies and can also provide novel research avenues for future biological and clinical studies.

UVRAG in autophagy, inflammation, and cancer

Macroautophagy/autophagy deregulation has been observed in perpetuated inflammation and the proliferation of tumor cells. However, the mechanisms underlying these changes have yet to be well-identified. UVRAG is one of the key players of autophagy, but its role in vivo remained puzzling. Our recent study utilized a mouse model with inducible expression of a cancer-derived frameshift (FS) mutation in UVRAG that dominant-negatively inhibits wild-type UVRAG, resulting in impaired stimulus-induced autophagy. The systemically compromised autophagy, particularly mitophagy, notably increases inflammation and associated pathologies. Furthermore, our discovery indicates that time-dependent autophagy suppression and ensuing CTNNB1/β-catenin activation may serve as one tumor-promoting mechanism underpinning age-related cancer susceptibility.

A truncating mutation in the autophagy gene UVRAG drives inflammation and tumorigenesis in mice

Aberrant autophagy is a major risk factor for inflammatory diseases and cancer. However, the genetic basis and underlying mechanisms are less established. UVRAG is a tumor suppressor candidate involved in autophagy, which is truncated in cancers by a frameshift (FS) mutation and expressed as a shortened UVRAGFS. To investigate the role of UVRAGFS in vivo, we generated mutant mice that inducibly express UVRAGFS (iUVRAGFS). These mice are normal in basal autophagy but deficient in starvation- and LPS-induced autophagy by disruption of the UVRAG-autophagy complex. iUVRAGFS mice display increased inflammatory response in sepsis, intestinal colitis, and colitis-associated cancer development through NLRP3-inflammasome hyperactivation. Moreover, iUVRAGFS mice show enhanced spontaneous tumorigenesis related to age-related autophagy suppression, resultant β-catenin stabilization, and centrosome amplification. Thus, UVRAG is a crucial autophagy regulator in vivo, and autophagy promotion may help prevent/treat inflammatory disease and cancer in susceptible individuals.

Safety and patient-reported outcomes of atezolizumab, carboplatin, and etoposide in extensive-stage small-cell lung cancer (IMpower133): a randomized phase I/III trial

BACKGROUND

The addition of atezolizumab to carboplatin and etoposide (CP/ET) significantly improved progression-free and overall survival for patients with extensive-stage small-cell lung cancer (ES-SCLC) in the IMpower133 study (NCT02763579). We have evaluated adverse events (AEs) and patient-reported outcomes in IMpower133 to assess the benefit-risk profile of this regimen.

PATIENTS AND METHODS

Patients received four 21-day cycles of CP/ET plus intravenous atezolizumab 1200 mg or placebo (induction phase), followed by atezolizumab or placebo (maintenance phase) until progression or loss of benefit. AEs were assessed and patient-reported outcomes were evaluated every 3 weeks during treatment using the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire - Core 30 (QLQ-C30) and QLQ-LC13.

RESULTS

Overall, 394 patients were assessable for safety in the induction phase and 318 in the maintenance phase. The frequency of AEs, grade 3-4 AEs, and serious AEs was similar between arms in both phases. Immune-related AEs were more frequent in the atezolizumab arm during both induction (28% versus 17%; leading to atezolizumab/placebo interruption 9% versus 5%, leading to withdrawal 4% versus 0%) and maintenance (26% versus 15%; leading to atezolizumab/placebo interruption, 3% versus 2%, leading to withdrawal 1% versus 1%), most commonly rash (induction 11% versus 9%, maintenance 14% versus 4%), and hypothyroidism (induction 4.0% versus 0%, maintenance 10% versus 1%). Changes in patient-reported treatment-related symptoms commonly associated with quality of life impairment were generally similar during induction and most of the maintenance phase. Patient-reported function and health-related quality of life (HRQoL) improved in both arms after initiating treatment, with more pronounced and persistent HRQoL improvements in the atezolizumab arm.

CONCLUSIONS

In patients with ES-SCLC, atezolizumab plus CP/ET has a comparable safety profile to placebo plus CP/ET, and the addition of atezolizumab did not adversely impact patient-reported HRQoL. These data demonstrate the positive benefit-risk profile of first-line atezolizumab plus CP/ET in ES-SCLC and further support this regimen as a new standard of care in this setting.

CLINICAL TRIALS NUMBER

NCT02763579.

Epidemiology of Clostridioides difficile infection in Canada: A six-year review to support vaccine decision-making

BACKGROUND

Two vaccines against Clostridioides difficile infections (CDI) are currently in phase III trials. To enable decision-making on their use in public health programs, national disease epidemiology is necessary.

OBJECTIVES

To determine the epidemiology of hospital-acquired CDI (HA-CDI) and community-associated CDI (CA-CDI) in Canada using provincial surveillance data and document discrepancies in CDI-related definitions among provincial surveillance programs.

METHODS

Publicly-available CDI provincial surveillance data from 2011 to 2016 that distinguished between HA-CDI and CA-CDI were included and the most common surveillance definitions for each province were used. The HA-, CA-CDI incidence rates and CA-CDI proportions (%) were calculated for each province. Both HA- and CA-CDI incidence rates were examined for trends. Types of disparities were summarized and detailed discrepancies were documented.

RESULTS

Canadian data were analyzed from nine provinces. The HA-CDI rates ranged from 2.1/10,000 to 6.5/10,000 inpatient-days, with a decreasing trend over time. Available data on CA-CDI showed that both rates and proportions have been increasing over time. Discrepancies among provincial surveillance definitions were documented in CDI case classifications, surveillance populations and rate calculations.

CONCLUSION

In Canada overall, the rate of HA-CDI has been decreasing and the rate of CA-CDI has been increasing, although this calculation was impeded by discrepancies in CDI-related definitions among provincial surveillance programs. Nationally-adopted common definitions for CDI would enable better comparisons of CDI rates between provinces and a calculation of the pan-Canadian burden of illness to support vaccine decision-making.

Revisiting the role of autophagy in melanoma

Although alterations of the macroautophagy/autophagy-lysosome pathway have been observed in cancer for many years, the mechanisms underlying these changes and the importance of autophagic and lysosomal reprogramming by cancer have yet to be well identified. Our recent study demonstrates that oncogenic BRAF signaling promotes melanoma growth and resistance to BRAF-targeted therapy through phosphorylation and functional inactivation of TFEB (transcription factor EB) and consequent suppression of the autophagy-lysosome gene network. This is by no means the first time that this pathway has been directly linked to oncogenic BRAF-driven melanoma. The key observations revealed in this study also leads to a complex but growing convergence of our understanding of the biology of the autophagy-lysosome pathway and the mechanisms underlying cancer prevention and treatment.

Transcriptional regulation of autophagy-lysosomal function in BRAF-driven melanoma progression and chemoresistance

Autophagy maintains homeostasis and is induced upon stress. Yet, its mechanistic interaction with oncogenic signaling remains elusive. Here, we show that in BRAFV600E-melanoma, autophagy is induced by BRAF inhibitor (BRAFi), as part of a transcriptional program coordinating lysosome biogenesis/function, mediated by the TFEB transcription factor. TFEB is phosphorylated and thus inactivated by BRAFV600E via its downstream ERK independently of mTORC1. BRAFi disrupts TFEB phosphorylation, allowing its nuclear translocation, which is synergized by increased phosphorylation/inactivation of the ZKSCAN3 transcriptional repressor by JNK2/p38-MAPK. Blockade of BRAFi-induced transcriptional activation of autophagy-lysosomal function in melanoma xenografts causes enhanced tumor progression, EMT-transdifferentiation, metastatic dissemination, and chemoresistance, which is associated with elevated TGF-β levels and enhanced TGF-β signaling. Inhibition of TGF-β signaling restores tumor differentiation and drug responsiveness in melanoma cells. Thus, the "BRAF-TFEB-autophagy-lysosome" axis represents an intrinsic regulatory pathway in BRAF-mutant melanoma, coupling BRAF signaling with TGF-β signaling to drive tumor progression and chemoresistance.

Darkening with UVRAG

Ultraviolet radiation (UVR)-induced skin pigmentation, afforded by the dark organelles termed melanosomes, accounts for the first-line protection against environmental UVR that increases the risk of developing skin cancers including melanoma. We have recently discovered that UVRAG, originally identified as a BECN1-binding macroautophagy/autophagy protein, appears to have a specialized function in melanosome biogenesis beyond autophagy through its interaction with the biogenesis of lysosome-related organelles complex 1 (BLOC-1). This melanogenic function of UVRAG is controlled by the melanocyte-specific transcription factor MITF as a downstream effector of the α-melanocyte-stimulating hormone (α-MSH)-cAMP signaling in the suntan response, which is compromised in BRAF mutant melanoma. Thus we propose a new mode of UVRAG activity and regulation in melanocyte biology that may affect melanoma predisposition.

Safety and effectiveness of neuraminidase inhibitors for influenza treatment, prophylaxis, and outbreak control: a systematic review of systematic reviews and/or meta-analyses

Objectives

To review evidence from systematic reviews and/or meta-analyses (SR/MAs) regarding neuraminidase inhibitor (NI) safety and effectiveness.

Methods

We conducted an SR of SR/MAs of randomized control and/or observational studies. We searched eight electronic databases for SR/MAs that examined the effectiveness or safety of NIs administered for influenza (i.e. influenza-like illness or lab-confirmed) treatment or prophylaxis.

Results

We identified 27 (0.7%) eligible SR/MAs of 3723 articles reviewed. NI (n = 2) or oseltamivir (n = 1) versus no treatment were consistently associated with a decrease in mortality odds among the hospitalized, general population (OR range 0.2 - 0.8). Oseltamivir versus no treatment was associated with a decrease in hospitalization and pneumonia risk/odds in 2/4 SR/MAs. Oseltamivir (n = 4) and zanamivir (n = 3) were consistently associated with a 0.5 - 1 day decrease in symptom duration. Oseltamivir (n = 4) or zanamivir (n = 4) versus no prophylaxis were consistently associated with a decrease in the odds/risk of symptomatic secondary transmission (OR/RR range 0.1 - 0.5). Oseltamivir versus no treatment was consistently associated with a 1.5- to 2.5-fold increase in the odds/risk of nausea (n = 4) and vomiting (n = 5).

Conclusions

NI treatment is likely to be effective at reducing mortality among hospitalized patients, and symptom duration by up to 1 day in the general population. Oseltamivir or zanamivir prophylaxis are likely to be effective at reducing secondary symptomatic influenza transmission. Increased nausea and vomiting are likely associated with oseltamivir use. We recommend that decisions regarding NI use are made in consideration of potential adverse events, particularly for the general population at low risk of complications. Among hospitalized patients, NI administration seems warranted to reduce mortality risk.

Safety and effectiveness of neuraminidase inhibitors in situations of pandemic and/or novel/variant influenza: a systematic review of the literature, 2009-15

Objectives

To review systematically the published literature evaluating neuraminidase inhibitor (NI) safety and effectiveness in situations of pandemic and novel/variant influenza.

Methods

We searched six online databases using comprehensive search criteria for observational studies and randomized controlled trials investigating the effects of NI treatment, prophylaxis or outbreak control in patients of all ages.

Results

Overall, 165 studies were included (95% observational), which were generally of low methodological quality due to lack of adjustment for confounding variables. In studies reporting adjusted estimates in general populations, NI treatment appeared likely to be effective against mortality (primarily if administered within 48 h of symptom onset) and potentially effective in reducing pneumonia. NIs appeared effective in reducing secondary transmission when indicated for prophylaxis. Limited, low-quality data suggest NIs are likely safe in general populations and may be safe in pregnant women and children. Data are scarce regarding safety of NIs in adults and high-risk individuals.

Conclusions

Most included studies were observational, statistically underpowered and at high risk of reporting biased and/or confounded effect estimates. NI treatment appeared likely effective in reducing mortality (cause unspecified) and pneumonia in general populations, with increasing benefit when administered with 48 h of symptom onset. NI pre- or post-exposure prophylaxis is likely effective in reducing secondary transmission of influenza in a general population. Our evidence suggests NIs are likely safe to use in the general population; however, data for children and pregnant women are limited. Knowledge gaps persist in specific populations such as Aboriginals, high-risk individuals and the elderly.

Comparative effectiveness of linezolid versus vancomycin as definitive antibiotic therapy for heterogeneously resistant vancomycin-intermediate coagulase-negative staphylococcal central-line-associated bloodstream infections in a neonatal intensive care unit

Objectives

Heterogeneously resistant vancomycin-intermediate coagulase-negative staphylococci (hVICoNS) are emerging pathogens causing central-line-associated bloodstream infections (CLABSIs) in neonatal intensive care unit (NICU) patients. Given the burden of disease associated with CLABSI and the current lack of therapeutic guidelines, we aimed to compare the effectiveness of linezolid versus vancomycin used as the definitive antibiotic therapy for hVICoNS CLABSI.

Methods

We performed a retrospective cohort study of infants with hVICoNS CLABSI from a single NICU between 2009 and 2014, treated with either linezolid or vancomycin as definitive antibiotic therapy. CLABSI duration, early and late recurrence and in-hospital mortality were compared using propensity score-adjusted proportional hazards and logistic regression models.

Results

Of 89 infants with hVICoNS CLABSI, 33 (37.1%) treated with linezolid were compared with 56 (62.9%) treated with vancomycin. The median duration of CLABSI was 5 (range 1-12) versus 4 days (range 0-14) ( P  =   0.11), early recurrences were 3.0% versus 7.1% ( P  =   0.42), late recurrences 0% versus 14.3% ( P  =   0.02) and mortality 27.3% versus 28.6% ( P  =   0.90), when treated with linezolid versus vancomycin, respectively. When adjusting using a continuous propensity score, linezolid had an HR of 0.78 (95% CI 0.48-1.27) for CLABSI duration, an OR of 0.23 (95% CI 0.02-2.56) for early recurrence and an OR of 0.9 (95% CI 0.3-2.67) for mortality, relative to vancomycin.

Conclusions

There was no statistically significant difference between linezolid and vancomycin when used as definitive treatment for hVICoNS CLABSI in NICU patients, in terms of CLABSI duration, recurrence or all-cause mortality.

Autophagy modulator plays a part in UV protection

Ultraviolet (UV)-induced DNA damage is a major risk factor for skin cancers including melanoma. UVRAG, originally identified to complement UV sensitivity in xeroderma pigmentosum (XP), has since been implicated in modulating macroautophagy/autophagy, in coordinating different intracellular trafficking pathways, and in maintaining chromosomal stability. Intriguingly, our recent study has demonstrated that UVRAG plays an essential role in protecting cells from UV-induced DNA damage by activating the nucleotide excision repair (NER) pathway. Since NER is the major mechanism by which cells maintain DNA integrity against UV insult, the inactivation of UVRAG seen in some melanoma may impart these cells with an ability to accumulate high-load UV mutagenesis, leading to cancer progression. Thus, this property of UVRAG has untapped potential to be of fundamental importance in understanding the genetics and pathogenesis of human skin cancer.

EP3/FP dual receptor agonist ONO-9054 administered morning or evening to patients with open-angle glaucoma or ocular hypertension: results of a randomised crossover study

Background/aims

The novel prostaglandin E (EP) 3 and prostaglandin F (FP) receptor agonist ONO-9054 is effective in lowering intraocular pressure (IOP) in patients with ocular hypertension and open-angle glaucoma when administered once daily. This study compares the effects of morning (AM) versus evening (PM) dosing of ONO-9054 on tolerability and IOP lowering.

Methods

This was a single-centre, randomised, double-masked, two-sequence, placebo-controlled crossover study in 12 subjects with bilateral primary open-angle glaucoma or ocular hypertension. Two 14-day crossover regimens were separated by a 2-week washout: ONO-9054 (1 drop to each eye) in the morning (07:00) and vehicle in the evening (19:00) and vice versa. IOP was measured multiple times during select days. Ocular examinations also evaluated safety and tolerability.

Results

Mild ocular hyperaemia, reported by six subjects with PM dosing, was the most frequent adverse event. Mild to moderate dryness was also slightly more frequent after PM dosing. Maximum IOP reduction from baseline occurred on day 2 with decreases from baseline of −7.4 mm Hg (−30.8%) for AM dosing and −9.1 mm Hg, (−38.0%) for PM dosing; after 14 days, mean reduction in IOP was −6.8 mm Hg (−28.6%) for AM dosing and −7.5 mm Hg (−31.0%) for PM dosing.

Conclusions

PM dosing of ONO-0954 was associated with a slightly increased frequency of mild hyperaemia and mild to moderate dryness. Both dosing schedules provided sustained reduction in IOP.

Trial registration number

NCT01670266.

Summary of the National Advisory Committee on Immunization's Statement on the re-immunization with polysaccharide 23-valent pneumococcal vaccine

BACKGROUND

Individuals who are 2 years of age and over and at high risk for invasive pneumococcal disease (IPD) (defined as those with functional or anatomic asplenia or sickle cell disease; hepatic cirrhosis; chronic renal failure or nephrotic syndrome; HIV infection; and immunosuppression related to disease or therapy) are recommended to receive one lifetime booster dose of polysaccharide 23-valent pneumococcal vaccine (Pneu-P-23) vaccine, in addition to age- and risk-specific recommendations for the conjugate 13-valent pneumococcal vaccine (Pneu-C-13). Adults aged 65 years and over are also considered at high risk for invasive pneumococcal disease (IPD).

OBJECTIVE

To determine the optimal time between initial vaccination with Pneu-P-23 and subsequent booster doses to protect against IPD in those at high risk for IPD.

METHODS

The National Advisory Committee on Immunization (NACI) conducted a systematic review of the literature on booster doses of pneumococcal vaccine for individuals at high risk for IPD disease. NACI reviewed the evidence considering the target population, safety, immunogenicity, efficacy, effectiveness of the vaccines, vaccine schedules, and other aspects of the overall immunization strategy, and then approved three specific recommendations.

RESULTS

For all individuals aged 2 years and over who are at high risk for IPD and who have received a dose of Pneu-P-23, re-vaccination with a second dose of Pneu-P-23 should be provided five years after the initial dose of Pneu-P-23. They should also have previously received age-appropriate doses of 13-valent conjugate pneumococcal vaccine. There is currently insufficient evidence to determine the optimal timing and number of Pneu-P-23 boosters in high-risk adults. One lifetime booster of Pneu-P-23 is currently recommended for individuals at high risk for IPD, five years after the previous dose. Given the increased risk of IPD in adults aged 65 years and older and the rapid decline in antibodies following Pneu-P-23, all individuals should receive one dose of Pneu-P-23 at age 65 years-as long as five years have passed since the previous Pneu-P-23 dose. No additional booster dose is currently recommended for this age group, if they have no medical conditions that put them at high risk for IPD.

CONCLUSION

The new and complete set of current recommendations for pneumococcal vaccines will be published in the updated "Pneumococcal" chapter in the Canadian Immunization Guide in the near future.

Determinants Of Oral corticosteroid Responsiveness in Wheezing Asthmatic Youth (DOORWAY): protocol for a prospective multicentre cohort study of children with acute moderate-to-severe asthma exacerbations

INTRODUCTION

Oral corticosteroids are the cornerstone of acute asthma management in the emergency department. Recent evidence has raised doubts about the efficacy of this treatment in preschool-aged children with viral-induced wheezing and in smoking adults. The aims of the study were to: (1) document the magnitude of response to oral corticosteroids in children presenting to the emergency department with moderate or severe asthma; (2) quantify potential determinants of response to corticosteroids and (3) explore the role of gene polymorphisms associated with the responsiveness to corticosteroids.

METHODS AND ANALYSIS

The design is a prospective cohort study of 1008 children aged 1-17 years meeting a strict definition of asthma and presenting with a clinical score of ≥4 on the validated Pediatric Respiratory Assessment Measure. All children will receive standardised severity-specific treatment with prednisone/prednisolone and cointerventions (salbutamol with/without ipratropium bromide). Determinants, namely viral aetiology, environmental tobacco smoke and single nucleotide polymorphism, will be objectively documented. The primary efficacy endpoint is the failure of emergency department (ED) management within 72 h of the ED visit. Secondary endpoints include other measures of asthma severity and time to recovery within 7 days of the index visit. The study has 80% power for detecting a risk difference of 7.5% associated with each determinant from a baseline risk of 21%, at an α of 0.05.

ETHICS AND DISSEMINATION

Ethical approval has been obtained from all participating institutions. An impaired response to systemic steroids in certain subgroups will challenge the current standard of practice and call for the immediate search for better approaches. A potential host-environment interaction will broaden our understanding of corticosteroid responsiveness in children. Documentation of similar effectiveness of corticosteroids across determinants will provide the needed reassurance regarding current treatment recommendations.

RESULTS

Results will be disseminated at international conferences and manuscripts targeted at emergency physicians, paediatricians, geneticists and respirologists.

TRIAL REGISTRATION NUMBER

This study is registered at Clinicaltrials.gov (NCT02013076).

In vitro activity of a novel ketolide ABT-773 against invasive strains of Streptococcus pneumoniae

New ketolides such as ABT-773 are a promising group of antibiotics in an era of increasing antibiotic resistance. We tested 704 invasive strains of Streptococcus pneumoniae collected from 1990 to 1998. Overall resistance was 8.3, 4.6, 4.5 and 3.6% for penicillin, cefuroxime, erythromycin and clarithromycin, respectively. By using a recommended breakpoint for susceptibility of <0.5 mg/L, no strains showed reduced susceptibility to ABT-773. ABT-773 was very active against all penicillin-resistant strains (MIC > 2 mg/L, with a mean geometric mean <0.06 mg/L), and against all 33 erythromycin-resistant strains, irrespective of the mode of resistance [mef- or erm(B)-mediated]. ABT-773 is a very active and promising agent against invasive strains of S. pneumoniae, including multiresistant strains.