Negative Cross-Talk between TLR2/4-Independent AMPKα1 and TLR2/4-Dependent JNK Regulates S. pneumoniae-Induced Mucosal Innate Immune Response.

Streptococcus pneumoniae is major cause of otitis media (OM) and life-threatening pneumonia. Overproduction of mucin, the major component of mucus, plays a critical role in the pathogenesis of both OM and pneumonia. However, the molecular mechanisms underlying the tight regulation of mucin upregulation in the mucosal epithelium by S. pneumoniae infection remain largely unknown. In this study, we show that S. pneumoniae pneumolysin (PLY) activates AMP-activated protein kinase α1 (AMPKα1), the master regulator of energy homeostasis, which is required for S. pneumoniae-induced mucin MUC5AC upregulation in vitro and in vivo. Moreover, we found that PLY activates AMPKα1 via cholesterol-dependent membrane binding of PLY and subsequent activation of the Ca2+- Ca2+/calmodulin-dependent kinase kinase ß (CaMKKß) and Cdc42-mixed-lineage protein kinase 3 (MLK3) signaling axis in a TLR2/4-independent manner. AMPKα1 positively regulates PLY-induced MUC5AC expression via negative cross-talk with TLR2/4-dependent activation of MAPK JNK, the negative regulator of MUC5AC expression. Moreover, pharmacological inhibition of AMPKα1 suppressed MUC5AC induction in the S. pneumoniae-induced OM mouse model, thereby demonstrating its therapeutic potential in suppressing mucus overproduction in OM. Taken together, our data unveil a novel mechanism by which negative cross-talk between TLR2/4-independent activation of AMPKα1 and TLR2/4-dependent activation of JNK tightly regulates the S. pneumoniae PLY-induced host mucosal innate immune response.

Cost-effectiveness analysis of dupilumab among patients with oral corticosteroid-dependent uncontrolled severe asthma in Japan.

BACKGROUND: Asthma is a common, chronic inflammatory airway disorder, with up to 1,177,000 people receiving asthma treatment in Japan. Dupilumab is a first-in-class, monoclonal antibody for the treatment of atopic diseases, including persistent asthma. The objective of this study was to assess the cost-effectiveness of dupilumab, compared with other biologics, as add-on treatment to background therapy in patients aged ≥12 years with uncontrolled, persistent asthma in Japan. METHODS: A life-time Markov cohort model was used to conduct cost-effectiveness analysis from the Japanese healthcare payer perspective with an annual discount rate of 2%. Dupilumab was compared with benralizumab and mepolizumab, and against omalizumab (as a hypothetical scenario). Inputs were informed by dupilumab clinical trials (VENTURE [NCT02528214] and QUEST [NCT02414854] trials), the literature, official Japanese sources and expert opinions. RESULTS: The base case results suggest that treatment with dupilumab leads to fewer severe exacerbations and increased life-years (LYs) and quality-adjusted LYs (QALYs) than benralizumab and mepolizumab. At a willingness-to-pay (WTP) threshold of ¥5,000,000 per QALY gained, dupilumab was the dominant strategy (lower cost, increased QALYs) versus benralizumab, and cost-effective versus mepolizumab with an incremental cost-effectiveness ratio (ICER) of ¥1,010,921 (US$9,190, US$1 = ¥110). Versus omalizumab, dupilumab was not cost-effective (ICER of ¥10,802,368 [US$98,203]). CONCLUSIONS: In Japan, dupilumab, as an add-on to background therapy, is economically dominant compared with benralizumab, and cost-effective versus mepolizumab.

Dupilumab efficacy and safety in Japanese patients with uncontrolled, moderate-to-severe asthma in the phase 3 LIBERTY ASTHMA QUEST study.

BACKGROUND: In the LIBERTY ASTHMA QUEST (ClinicalTrials.gov: NCT02414854) study, dupilumab 200 mg and 300 mg every 2 weeks vs matched-volume placebo reduced severe asthma exacerbations and improved lung function (FEV1), asthma control, and quality of life in patients with uncontrolled, moderate-to-severe asthma (N = 1902). Here, we examine the safety and efficacy of dupilumab in the subpopulation of Japanese patients who participated in QUEST (n = 114; 6%). METHODS: Endpoints assessed were annualized severe exacerbation rates and the effect of treatment over the 52-week treatment period on FEV1, asthma control, asthma-related quality of life, and markers of type 2 inflammation. RESULTS: In Japanese patients, dupilumab 200 and 300 mg every 2 weeks vs matched placebo reduced severe asthma exacerbation rates by 44% (P = 0.33) and 75% (P = 0.03), respectively, and improved FEV1 at Week 12 by 0.20 L (P = 0.05) and 0.17 L (P = 0.12). FEV1 improvements were rapid (by Week 2) and sustained throughout treatment. Significant and/or numerical improvements vs placebo in asthma control and quality of life were also observed throughout treatment. For each endpoint, greater efficacy was observed in patients with elevated baseline levels of type 2 inflammatory biomarkers (blood eosinophils or FeNO). Dupilumab treatment significantly reduced levels of FeNO and total IgE, but not blood eosinophils. CONCLUSIONS: In this subanalysis of QUEST, the efficacy and safety of dupilumab in Japanese patients was comparable to that observed in the overall intention-to-treat population, suggesting no variability in efficacy on the basis of Japanese ethnicity. (Funded by Sanofi and Regeneron Pharmaceuticals, Inc.; ClinicalTrials.gov number: NCT02414854).

Chaperone-Independent Peripheral Quality Control of CFTR by RFFL E3 Ligase.

The peripheral protein quality control (QC) system removes non-native membrane proteins, including ΔF508-CFTR, the most common CFTR mutant in cystic fibrosis (CF), from the plasma membrane (PM) for lysosomal degradation by ubiquitination. It remains unclear how unfolded membrane proteins are recognized and targeted for ubiquitination and how they are removed from the apical PM. Using comprehensive siRNA screens, we identified RFFL, an E3 ubiquitin (Ub) ligase that directly and selectively recognizes unfolded ΔF508-CFTR through its disordered regions. RFFL retrieves the unfolded CFTR from the PM for lysosomal degradation by chaperone-independent K63-linked poly-ubiquitination. RFFL ablation enhanced the functional expression of cell-surface ΔF508-CFTR in the presence of folding corrector molecules, and this effect was further improved by inhibiting the Hsc70-dependent ubiquitination machinery. We propose that multiple peripheral QC mechanisms evolved to dispose of non-native PM proteins and to preserve cellular proteostasis, even at the cost of eliminating partially functional polypeptides.

Questionnaire about Snoring and Daytime Sleepiness Due to Springtime Hay Fever.

Bothersome symptoms of hay fever impair not only patients' quality of life but also their labor productivity and learning efficiency. Excessive daytime sleepiness (EDS) caused by hay fever is thought to be one of the reasons for these impairments. The purpose of this study was to investigate the relationship between the severity of springtime hay fever and EDS by using a questionnaire. The questionnaire included information about age, sex, height, weight, severity of hay fever, treatment for hay fever, smoking and alcohol consumption habit, history of drug use for sleeping, existence of snoring, and Japanese version of the Epworth Sleepiness Scale. After excluding responses containing insufficient data, responses from 1,734 patients were considered as eligible. By performing logistic regression analysis, we analyzed the effect of the aforementioned parameters on the comorbidity of EDS and snoring. The odds ratio (OR) to comorbid EDS was significantly higher in the moderate and severe hay fever groups than in the asymptomatic hay fever group (moderate: OR=1.76, p=0.014, severe: OR=2.53, p<0.001). Also, OR to comorbid snoring was significantly higher in the severe hay fever group than in the asymptomatic hay fever group (severe: OR=1.90, p=0.001).

Deubiquitinase CYLD acts as a negative regulator for bacterium NTHi-induced inflammation by suppressing K63-linked ubiquitination of MyD88.

Myeloid differentiation factor 88 (MyD88) acts as a crucial adaptor molecule for Toll-like receptors (TLRs) and interleukin (IL)-1 receptor signaling. In contrast to the well-studied positive regulation of MyD88 signaling, how MyD88 signaling is negatively regulated still remains largely unknown. Here, we demonstrate for the first time to our knowledge that MyD88 protein undergoes lysine 63 (K63)-linked polyubiquitination, which is functionally critical for mediating TLR-MyD88-dependent signaling. Deubiquitinase CYLD negatively regulates MyD88-mediated signaling by directly interacting with MyD88 and deubiquitinating nontypeable Haemophilus influenzae (NTHi)-induced K63-linked polyubiquitination of MyD88 at lysine 231. Importantly, we further confirmed this finding in the lungs of mice in vivo by using MyD88(-/-)CYLD(-/-) mice. Understanding how CYLD deubiquitinates K63-linked polyubiquitination of MyD88 may not only bring insights into the negative regulation of TLR-MyD88-dependent signaling, but may also lead to the development of a previously unidentified therapeutic strategy for uncontrolled inflammation.

Nontypeable Haemophilus influenzae-Induced MyD88 Short Expression Is Regulated by Positive IKKß and CREB Pathways and Negative ERK1/2 Pathway.

Airway diseases such as asthma and chronic obstructive pulmonary disease (COPD) are characterized by excessive inflammation and are exacerbated by nontypeable Haemophilus influenzae (NTHi). Airway epithelial cells mount the initial innate immune responses to invading pathogens and thus modulate inflammation. While inflammation is necessary to eliminate a pathogen, excessive inflammation can cause damage to the host tissue. Therefore, the inflammatory response must be tightly regulated and deciphering the signaling pathways involved in this response will enhance our understanding of the regulation of the host inflammatory response. NTHi binds to TLR2 and signal propagation requires the adaptor molecule myeloid differentiation factor 88 (MyD88). An alternative spliced form of MyD88 is called MyD88 short (MyD88s) and has been identified in macrophages and embryonic cell lines as a negative regulator of inflammation. However, the role of MyD88s in NTHi-induced inflammation in airway epithelial cells remains unknown. Here we show that NTHi induces MyD88s expression and MyD88s is a negative regulator of inflammation in airway epithelial cells. We further demonstrate that MyD88s is positively regulated by IKKß and CREB and negatively regulated by ERK1/2 signaling pathways. Taken together these data indicate that airway inflammation is controlled in a negative feedback manner involving MyD88s and suggest that airway epithelial cells are essential to maintain immune homeostasis.

A structure-activity relationship of non-peptide macrocyclic histone deacetylase inhibitors and their anti-proliferative and anti-inflammatory activities.

Inhibition of the enzymatic activity of histone deacetylase (HDAC) is a promising therapeutic strategy for cancer treatment and several distinct small molecule histone deacetylase inhibitors (HDACi) have been reported. We have previously identified a new class of non-peptide macrocyclic HDACi derived from 14- and 15-membered macrolide skeletons. In these HDACi, the macrocyclic ring is linked to the zinc chelating hydroxamate moiety through a para-substituted aryl-triazole cap group. To further delineate the depth of the SAR of this class of HDACi, we have synthesized series of analogous compounds and investigated the influence of various substitution patterns on their HDAC inhibitory, anti-proliferative and anti-inflammatory activities. We identified compounds 25b and 38f with robust anti-proliferative activities and compound 26f (IC50 47.2 nM) with superior anti-inflammatory (IC50 88 nM) activity relative to SAHA.

Vinpocetine inhibits Streptococcus pneumoniae-induced upregulation of mucin MUC5AC expression via induction of MKP-1 phosphatase in the pathogenesis of otitis media.

Mucin overproduction is a hallmark of otitis media (OM). Streptococcus pneumoniae is one of the most common bacterial pathogens causing OM. Mucin MUC5AC plays an important role in mucociliary clearance of bacterial pathogens. However, if uncontrolled, excessive mucus contributes significantly to conductive hearing loss. Currently, there is a lack of effective therapeutic agents that suppress mucus overproduction. In this study, we show that a currently existing antistroke drug, vinpocetine, a derivative of the alkaloid vincamine, inhibited S. pneumoniae-induced mucin MUC5AC upregulation in cultured middle ear epithelial cells and in the middle ear of mice. Moreover, vinpocetine inhibited MUC5AC upregulation by inhibiting the MAPK ERK pathway in an MKP-1-dependent manner. Importantly, ototopical administration of vinpocetine postinfection inhibited MUC5AC expression and middle ear inflammation induced by S. pneumoniae and reduced hearing loss and pneumococcal loads in a well-established mouse model of OM. Thus, these studies identified vinpocetine as a potential therapeutic agent for inhibiting mucus production in the pathogenesis of OM.

Cross-talk between PKA-Cß and p65 mediates synergistic induction of PDE4B by roflumilast and NTHi.

Phosphodiesterase 4B (PDE4B) plays a key role in regulating inflammation. Roflumilast, a phosphodiesterase (PDE)4-selective inhibitor, has recently been approved for treating severe chronic obstructive pulmonary disease (COPD) patients with exacerbation. However, there is also clinical evidence suggesting the development of tachyphylaxis or tolerance on repeated dosing of roflumilast and the possible contribution of PDE4B up-regulation, which could be counterproductive for suppressing inflammation. Thus, understanding how PDE4B is up-regulated in the context of the complex pathogenesis and medications of COPD may help improve the efficacy and possibly ameliorate the tolerance of roflumilast. Here we show that roflumilast synergizes with nontypeable Haemophilus influenzae (NTHi), a major bacterial cause of COPD exacerbation, to up-regulate PDE4B2 expression in human airway epithelial cells in vitro and in vivo. Up-regulated PDE4B2 contributes to the induction of certain important chemokines in both enzymatic activity-dependent and activity-independent manners. We also found that protein kinase A catalytic subunit ß (PKA-Cß) and nuclear factor-κB (NF-κB) p65 subunit were required for the synergistic induction of PDE4B2. PKA-Cß phosphorylates p65 in a cAMP-dependent manner. Moreover, Ser276 of p65 is critical for mediating the PKA-Cß-induced p65 phosphorylation and the synergistic induction of PDE4B2. Collectively, our data unveil a previously unidentified mechanism underlying synergistic up-regulation of PDE4B2 via a cross-talk between PKA-Cß and p65 and may help develop new therapeutic strategies to improve the efficacy of PDE4 inhibitor.

Glucocorticoids suppress inflammation via the upregulation of negative regulator IRAK-M.

Glucocorticoids are among the most commonly used anti-inflammatory agents. Despite the enormous efforts in elucidating the glucocorticoid-mediated anti-inflammatory actions, how glucocorticoids tightly control overactive inflammatory response is not fully understood. Here we show that glucocorticoids suppress bacteria-induced inflammation by enhancing IRAK-M, a central negative regulator of Toll-like receptor signalling. The ability of glucocorticoids to suppress pulmonary inflammation induced by non-typeable Haemophilus influenzae is significantly attenuated in IRAK-M-deficient mice. Glucocorticoids improve the survival rate after a lethal non-typeable Haemophilus influenzae infection in wild-type mice, but not in IRAK-M-deficient mice. Moreover, we show that glucocorticoids and non-typeable Haemophilus influenzae synergistically upregulate IRAK-M expression via mutually and synergistically enhancing p65 and glucocorticoid receptor binding to the IRAK-M promoter. Together, our studies unveil a mechanism by which glucocorticoids tightly control the inflammatory response and host defense via the induction of IRAK-M and may lead to further development of anti-inflammatory therapeutic strategies.

CYLD negatively regulates nontypeable Haemophilus influenzae-induced IL-8 expression via phosphatase MKP-1-dependent inhibition of ERK.

Nontypeable Haemophilus influenzae (NTHi), a Gram-negative bacterium, is the primary cause of otitis media in children and the exacerbation of chronic obstructive pulmonary disease in adults. A hallmark of both diseases is an overactive inflammatory response, including the upregulation of chemokines, such as interleukin-8 (IL-8). An appropriate inflammatory response is essential for eradicating pathogens. However, excessive inflammation can cause host tissue damage. Therefore, expression of IL-8 must be tightly regulated. We previously reported that NTHi induces IL-8 expression in an ERK-dependent manner. We also have shown that the deubiquitinase cylindromatosis (CYLD) suppresses NTHi-induced inflammation. However, the underlying molecular mechanism of how CYLD negatively regulates ERK-mediated IL-8 production is largely unknown. Here, we examine both human lung epithelial A549 cells and lung of Cyld-/- mice to show that CYLD specifically targets the activation of ERK. Interestingly, CYLD enhances NTHi-induced upregulation of another negative regulator, MAP Kinase Phosphatase-1 (MKP-1), which, in turn, leads to reduced ERK activation and subsequent suppression of IL-8. Taken together, the CYLD suppression of ERK-dependent IL-8 via MKP-1 may bring novel insights into the tight regulation of inflammatory responses and also lead to innovative therapeutic strategies for controlling these responses by targeting key negative regulators of inflammation.

Inhibition of PDE4B suppresses inflammation by increasing expression of the deubiquitinase CYLD.

The deubiquitinase CYLD acts as a key negative regulator to tightly control overactive inflammation. Most anti-inflammatory strategies have focused on directly targeting the positive regulator, which often results in significant side effects such as suppression of the host defence response. Here, we show that inhibition of phosphodiesterase 4B (PDE4B) markedly enhances upregulation of CYLD expression in response to bacteria, thereby suggesting that PDE4B acts as a negative regulator for CYLD. Interestingly, in Cyld-deficient mice, inhibition of PDE4B no longer suppresses inflammation. Moreover, PDE4B negatively regulates CYLD via specific activation of JNK2 but not JNK1. Importantly, ototopical post-inoculation administration of a PDE4 inhibitor suppresses inflammation in this animal model, thus demonstrating the therapeutic potential of targeting PDE4. These studies provide insights into how inflammation is tightly regulated via the inhibition of its negative regulator and may also lead to the development of new anti-inflammatory therapeutics that upregulate CYLD expression.

STT3B-dependent posttranslational N-glycosylation as a surveillance system for secretory protein.

Nascent secretory proteins are extensively scrutinized at the endoplasmic reticulum (ER). Various signatures of client proteins, including exposure of hydrophobic patches or unpaired sulfhydryls, are coordinately utilized to reduce nonnative proteins in the ER. We report here the cryptic N-glycosylation site as a recognition signal for unfolding of a natively nonglycosylated protein, transthyretin (TTR), involved in familial amyloidosis. Folding and ER-associated degradation (ERAD) perturbation analyses revealed that prolonged TTR unfolding induces externalization of cryptic N-glycosylation site and triggers STT3B-dependent posttranslational N-glycosylation. Inhibition of posttranslational N-glycosylation increases detergent-insoluble TTR aggregates and decreases cell proliferation of mutant TTR-expressing cells. Moreover, this modification provides an alternative pathway for degradation, which is EDEM3-mediated N-glycan-dependent ERAD, distinct from the major pathway of Herp-mediated N-glycan-independent ERAD. Hence we postulate that STT3B-dependent posttranslational N-glycosylation is part of a triage-salvage system recognizing cryptic N-glycosylation sites of secretory proteins to preserve protein homeostasis.

CYLD negatively regulates transforming growth factor-ß-signalling via deubiquitinating Akt.

Lung injury, whether induced by infection or caustic chemicals, initiates a series of complex wound-healing responses. If uncontrolled, these responses may lead to fibrotic lung diseases and loss of function. Thus, resolution of lung injury must be tightly regulated. The key regulatory proteins required for tightly controlling the resolution of lung injury have yet to be identified. Here we show that loss of deubiquitinase CYLD led to the development of lung fibrosis in mice after infection with Streptococcus pneumoniae. CYLD inhibited transforming growth factor-ß-signalling and prevented lung fibrosis by decreasing the stability of Smad3 in an E3 ligase carboxy terminus of Hsc70-interacting protein-dependent manner. Moreover, CYLD decreases Smad3 stability by deubiquitinating K63-polyubiquitinated Akt. Together, our results unveil a role for CYLD in tightly regulating the resolution of lung injury and preventing fibrosis by deubiquitinating Akt. These studies may help develop new therapeutic strategies for preventing lung fibrosis.

Fine-needle aspiration biopsy of low-grade cribriform cystadenocarcinoma of the salivary gland.

Low-grade cribriform cystadenocarcinoma (LGCCC) is a rare tumor, defined in the 2005 WHO classification as a primary salivary duct tumor. Previously, the neoplasm had been recognized as a variant of salivary duct carcinomas. A 56-year-old Japanese woman noticed a mass in the left subaural region. On radiological examinations, a multicystic tumor was seen in the left parotid gland. Fine-needle aspiration biopsy was performed. The smears revealed several characteristic cytologic features. The tumor cells were arranged in irregular overlapping and showed inconspicuous nuclear atypia with variable-sized and irregularly shaped cytoplasmic vacuoles. Based on these findings, a cystic tumor with uncertain malignancy was diagnosed. A parotidectomy was performed, because the tumor was slowly growing and contained solid components on the radiological images. Based on the histologic findings, along with immunohistochemistry, LGCCC was diagnosed based on resemblance to breast low-grade ductal carcinoma in situ and intraductal proliferation of tumor cells. This is the first report of the cytomorphological findings of LGCCC.

The crystal structure of the green tea polyphenol (-)-epigallocatechin gallate-transthyretin complex reveals a novel binding site distinct from the thyroxine binding site.

Amyloid fibril formation is associated with protein misfolding disorders, including neurodegenerative diseases such as Alzheimer's, Parkinson's, and Huntington's diseases. Familial amyloid polyneuropathy (FAP) is a hereditary disease caused by a point mutation of the human plasma protein, transthyretin (TTR), which binds and transports thyroxine (T(4)). TTR variants contribute to the pathogenesis of amyloidosis by forming amyloid fibrils in the extracellular environment. A recent report showed that epigallocatechin 3-gallate (EGCG), the major polyphenol component of green tea, binds to TTR and suppresses TTR amyloid fibril formation. However, structural analysis of EGCG binding to TTR has not yet been conducted. Here we first investigated the crystal structure of the EGCG-V30M TTR complex and found novel binding sites distinct from the thyroxine binding site, suggesting that EGCG has a mode of action different from those of previous chemical compounds that were shown to bind and stabilize the TTR tetramer structure. Furthermore, EGCG induced the oligomerization and monomer suppression in the cellular system of clinically reported TTR variants. Taken together, these findings suggest the possibility that EGCG may be a candidate compound for FAP therapy.

TGF-beta signaling may play a role in the development of goblet cell hyperplasia in a mouse model of allergic rhinitis.

BACKGROUND: Transforming growth factor-beta (TGF-beta) levels are elevated in the nasal mucosa in allergic rhinitis. However, because TGF-beta is secreted extracellulary in latent complexes, it remains unclear whether the local TGF-beta expression actually drives active signaling and affects the pathophysiology of allergic rhinitis. The objective of this study is to investigate whether TGF-beta signaling is activated in allergic rhinitis and plays a role in the pathophysiology of allergic rhinitis. METHODS: An ovabumin (OVA)-sensitized and -nasally challenged mouse model of allergic rhinitis was established and phosphorylation of Smad2 in the nasal mucosa was examined by immunohistochemistry. In addition, the effects of the pharmacological inhibition of endogenous TGF-beta signaling on the allergic rhinitis model were histologically examined. Furthermore, phosphorylation of Smad2 in the nasal mucosa samples obtained from patients with allergic rhinitis was also evaluated. RESULTS: In the mouse model of allergic rhinitis, OVA challenge induced phosphorylation of Smad2 predominantly in epithelial cells in the nasal mucosa. In addition, the administration of an inhibitor of TGF-beta type I receptor kinase activity during OVA challenge suppressed goblet cell hyperplasia in the nasal mucosa. Furthermore, phosphorylated Smad2 expression increased in nasal epithelial cells in patients with allergic rhinitis. CONCLUSIONS: These results suggest that TGF-beta signaling is activated in epithelial cells in the nasal mucosa in allergic rhinitis and may contribute to the development of goblet cell hyperplasia.

Asthma: Chronopharmacotherapy and the molecular clock.

Bronchial asthma is characterized by chronic airways inflammation and reversible airflow limitation. In patients with asthma, symptoms generally worsen during the early hours of the morning, and pulmonary function often deteriorates at the same time, suggesting a role for chronopharmacotherapy. Several drugs for asthma have been developed based on chronopharmacology. Most medications employed for the chronotherapy of asthma are administered once at night with the goal of preventing chronic airway inflammation or development of airflow limitation. In addition to bronchodilators, the inhaled glucocorticosteroid ciclesonide is now available with once-daily dosing, which also improves patients' compliance. Numerous investigations have demonstrated the usefulness of chronotherapy for asthma, especially for patients with nocturnal asthma. This review focuses on chronotherapy of asthma, and also provides a molecular biological explanation for the influence of asthma medications on the clock genes.