Innate Immune Landscape in Early Lung Adenocarcinoma by Paired Single-Cell Analyses.

To guide the design of immunotherapy strategies for patients with early stage lung tumors, we developed a multiscale immune profiling strategy to map the immune landscape of early lung adenocarcinoma lesions to search for tumor-driven immune changes. Utilizing a barcoding method that allows a simultaneous single-cell analysis of the tumor, non-involved lung, and blood cells, we provide a detailed immune cell atlas of early lung tumors. We show that stage I lung adenocarcinoma lesions already harbor significantly altered T cell and NK cell compartments. Moreover, we identified changes in tumor-infiltrating myeloid cell (TIM) subsets that likely compromise anti-tumor T cell immunity. Paired single-cell analyses thus offer valuable knowledge of tumor-driven immune changes, providing a powerful tool for the rational design of immune therapies. VIDEO ABSTRACT.

Hexokinase Is an Innate Immune Receptor for the Detection of Bacterial Peptidoglycan.

Degradation of Gram-positive bacterial cell wall peptidoglycan in macrophage and dendritic cell phagosomes leads to activation of the NLRP3 inflammasome, a cytosolic complex that regulates processing and secretion of interleukin (IL)-1ß and IL-18. While many inflammatory responses to peptidoglycan are mediated by detection of its muramyl dipeptide component in the cytosol by NOD2, we report here that NLRP3 inflammasome activation is caused by release of N-acetylglucosamine that is detected in the cytosol by the glycolytic enzyme hexokinase. Inhibition of hexokinase by N-acetylglucosamine causes its dissociation from mitochondria outer membranes, and we found that this is sufficient to activate the NLRP3 inflammasome. In addition, we observed that glycolytic inhibitors and metabolic conditions affecting hexokinase function and localization induce inflammasome activation. While previous studies have demonstrated that signaling by pattern recognition receptors can regulate metabolic processes, this study shows that a metabolic enzyme can act as a pattern recognition receptor. PAPERCLIP.

A conserved dendritic-cell regulatory program limits antitumour immunity.

Checkpoint blockade therapies have improved cancer treatment, but such immunotherapy regimens fail in a large subset of patients. Conventional type 1 dendritic cells (DC1s) control the response to checkpoint blockade in preclinical models and are associated with better overall survival in patients with cancer, reflecting the specialized ability of these cells to prime the responses of CD8+ T cells1-3. Paradoxically, however, DC1s can be found in tumours that resist checkpoint blockade, suggesting that the functions of these cells may be altered in some lesions. Here, using single-cell RNA sequencing in human and mouse non-small-cell lung cancers, we identify a cluster of dendritic cells (DCs) that we name 'mature DCs enriched in immunoregulatory molecules' (mregDCs), owing to their coexpression of immunoregulatory genes (Cd274, Pdcd1lg2 and Cd200) and maturation genes (Cd40, Ccr7 and Il12b). We find that the mregDC program is expressed by canonical DC1s and DC2s upon uptake of tumour antigens. We further find that upregulation of the programmed death ligand 1 protein-a key checkpoint molecule-in mregDCs is induced by the receptor tyrosine kinase AXL, while upregulation of interleukin (IL)-12 depends strictly on interferon-γ and is controlled negatively by IL-4 signalling. Blocking IL-4 enhances IL-12 production by tumour-antigen-bearing mregDC1s, expands the pool of tumour-infiltrating effector T cells and reduces tumour burden. We have therefore uncovered a regulatory module associated with tumour-antigen uptake that reduces DC1 functionality in human and mouse cancers.

Author Correction: A conserved dendritic-cell regulatory program limits antitumour immunity.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Genetic coding variant in complement factor B (CFB) is associated with increased risk for perianal Crohn's disease and leads to impaired CFB cleavage and phagocytosis.

OBJECTIVE: Perianal Crohn's disease (pCD) occurs in up to 40% of patients with CD and is associated with poor quality of life, limited treatment responses and poorly understood aetiology. We performed a genetic association study comparing CD subjects with and without perianal disease and subsequently performed functional follow-up studies for a pCD associated SNP in Complement Factor B (CFB). DESIGN: Immunochip-based meta-analysis on 4056 pCD and 11 088 patients with CD from three independent cohorts was performed. Serological and clinical variables were analysed by regression analyses. Risk allele of rs4151651 was introduced into human CFB plasmid by site-directed mutagenesis. Binding of recombinant G252 or S252 CFB to C3b and its cleavage was determined in cell-free assays. Macrophage phagocytosis in presence of recombinant CFB or serum from CFB risk, or protective CD or healthy subjects was assessed by flow cytometry. RESULTS: Perianal complications were associated with colonic involvement, OmpC and ASCA serology, and serology quartile sum score. We identified a genetic association for pCD (rs4151651), a non-synonymous SNP (G252S) in CFB, in all three cohorts. Recombinant S252 CFB had reduced binding to C3b, its cleavage was impaired, and complement-driven phagocytosis and cytokine secretion were reduced compared with G252 CFB. Serine 252 generates a de novo glycosylation site in CFB. Serum from homozygous risk patients displayed significantly decreased macrophage phagocytosis compared with non-risk serum. CONCLUSION: pCD-associated rs4151651 in CFB is a loss-of-function mutation that impairs its cleavage, activation of alternative complement pathway, and pathogen phagocytosis thus implicating the alternative complement pathway and CFB in pCD aetiology.

Malignant pleural mesothelioma characteristics and outcomes: A SEER-Medicare analysis.

BACKGROUND: Pleural mesothelioma is rare cancer linked to asbestos exposure. Previous research has indicated that female individuals have better survival than male individuals, but this has never been examined in the Surveillance, Epidemiology, and End Results (SEER)-Medicare database. MATERIALS AND METHODS: Malignant pleural mesothelioma cases diagnosed from 1992 to 2015 were queried from the linked SEER-Medicare database. Multivariable logistic regression was used to assess the clinical and demographic factors associated with sex. A multivariable Cox proportional hazards model and propensity matching methods were used to assess sex differences in overall survival (OS) while accounting for potential confounders. RESULTS: Among 4201 patients included in the analysis, 3340 (79.5%) were males and 861 (20.5%) females. Females were significantly older, with more epithelial histology than males were, and had significantly better OS, adjusted for confounders (adjusted hazard ratio, 0.83, 95% confidence interval: 0.76-0.90). Other variables independently associated with improved survival included younger age at diagnosis, having a spouse/domestic partner, epithelial histology, lower comorbidity score, and receipt of surgery or chemotherapy. CONCLUSIONS: The study describes sex differences in mesothelioma occurrence, treatment, and survival and is the first to examine SEER-Medicare. It provides directions for future research into potential therapeutic targets.

Biomarkers for checkpoint inhibitor therapy in mucinous epithelial ovarian cancer.

OBJECTIVE: The prognosis of patients with advanced stage mucinous epithelial ovarian cancer remains poor due to a modest response to platinum-based chemotherapy and the absence of therapeutic alternatives. As targeted approaches may help to overcome these limitations, the present study evaluates biomarkers indicative of potential immune-checkpoint inhibitor therapy response. METHODS: All patients who underwent primary cytoreductive surgery from January 2001 to December 2020 and for whom formalin-fixed paraffin-embedded tissue samples were available were included (n=35; 12 International Federation of Gynecology and Obstetrics (FIGO) stage ≥IIb). To define sub-groups potentially suitable for checkpoint inhibition, expression of programmed death-ligand 1 (PD-L1), tumor-infiltrating lymphocytes (CD3+, CD8+, CD20+, CD45+, CD68+, FoxP3+), and AT-rich interactive domain-containing protein 1A (ARID1A) immunostaining were evaluated in whole tissue sections and compared with clinicopathologic parameters and next-generation sequencing results, where available (n=11). Survival analyses were performed to assess whether identified sub-groups were associated with specific clinical outcomes. RESULTS: In total, 34.3% (n=12/35) of tumors were PD-L1 positive. PD-L1 expression was associated with infiltrative histotype (p=0.027) and correlated with higher CD8+ (r=0.577, p<0.001) and CD45+ (r=0.424, p=0.011), but reduced ARID1A expression (r=-4.39, p=0.008). CD8+ expression was associated with longer progression-free survival (hazard ratio (HR) 0.85 (95% CI 0.72 to 0.99), p=0.047) and disease-specific survival (HR 0.85 (95% CI 0.73 to 1.00), p=0.044) in the sub-group with FIGO stage ≥IIb. Three (8.6%) samples demonstrated high PD-L1 expression at a combined positive score of >10, which was associated with increased CD8+ expression (p=0.010) and loss of ARID1A expression (p=0.034). Next-generation sequencing, which was available for all samples with a combined positive score of >10, showed KRAS mutations, BRCA wild-type status, and mismatch repair proficiency in all cases, but did not reveal genetic alterations potentially associated with a pro-immunogenic tumor environment. CONCLUSIONS: A sub-group of mucinous ovarian cancers appear to demonstrate a pro-immunogenic tumor environment with high PD-L1 expression, decreased ARID1A expression, and characteristic tumor-infiltrating lymphocyte infiltration patterns. Further clinical validation of anti-PD-L1/PD-1 targeting in selected mucinous ovarian cancers appears promising.

Evolution of treatment patterns and survival outcomes in patients with advanced non-small cell lung cancer treated at Frankfurt University Hospital in 2012-2018.

BACKGROUND: Immune checkpoint inhibitors (ICIs) have improved outcomes for patients with advanced non-small cell lung cancer (NSCLC) versus chemotherapy in clinical trials. In Germany, ICIs have been used clinically since 2015 for patients with advanced/metastatic NSCLC without epidermal growth factor receptor (EGFR)/anaplastic lymphoma kinase (ALK) aberrations. As part of I-O Optimise, a multinational research program utilizing real-world data on thoracic malignancies, we describe real-world treatment patterns and survival following reimbursement of ICIs for advanced NSCLC in Germany. METHODS: This retrospective cohort study included patients with locally advanced/metastatic NSCLC without known EGFR/ALK aberrations who received a first line of therapy at Frankfurt University Hospital between January 2012 and December 2018, with follow-up to December 2019 or death, whichever occurred first. Using electronic medical records, treatment patterns and survival outcomes were described by histology (squamous cell [SQ]; non-squamous cell [NSQ]/other) and time period (pre- and post-ICI approval). RESULTS: Among eligible patients who started first-line treatment, 136 (pre-ICI) and 126 (post-ICI) had NSQ/other histology, and 32 (pre-ICI) and 38 (post-ICI) had SQ histology. Use of an ICI in the NSQ/other cohort increased from 5.9% (all second- or third-line) in the pre-ICI period to 57.1% (22.2% in first-line, including 13.5% as monotherapy and 8.7% combined with chemotherapy) in the post-ICI period. This was paralleled by a significant (P < 0.0001) prolongation of median (95% CI) OS from 9.4 (7.1-11.1) to 14.8 (12.7-20.5) months between the pre-ICI and post-ICI periods. A similar increase in the uptake of ICI was observed for the SQ cohort (from 3.1% pre-ICI [fourth-line] to 52.6% post-ICI [28.9% as first-line, including 15.8% as monotherapy and 13.2% combined with chemotherapy]); however, analysis of survival outcomes was limited by small group sizes. CONCLUSION: These real-world data complement clinical trial evidence on the effectiveness of ICIs in patients with advanced NSCLC and NSQ/other histology in Germany.

Measuring the margin distance in pulmonary wedge resection.

BACKGROUND: Margin distance contributes to survival and recurrence during wedge resections for early-stage non-small cell lung cancer. The Initiative for Early Lung Cancer Research on Treatment sought to standardize a surgeon-measured margin intraoperatively. METHODS: Lung cancer patients who underwent wedge resection were reviewed. Margins were measured by the surgeon twice as per a standardized protocol. Intraobserver variability as well as surgeon-pathologist variability were compared. RESULTS: Forty-five patients underwent wedge resection. Same-surgeon measurement analysis indicated good reliability with a small mean difference and narrow limit of agreement for the two measures. The median surgeon-measured margin was 18.0 mm, median pathologist-measured margin was 16.0 mm and the median difference between the surgeon-pathologist margin was -1.0 mm, ranging from -18.0 to 12.0 mm. Bland-Altman analysis for margin measurements demonstrated a mean difference of 0.65 mm. The limit of agreement for the two approaches were wide, with the difference lying between -16.25 and 14.96 mm. CONCLUSIONS: A novel protocol of surgeon-measured margin was evaluated and compared with pathologist-measured margin. High intraobserver agreement for repeat surgeon measurements yet low-to-moderate correlation or directionality between surgeon and pathologic measurements were found. DISCUSSION: A standardized protocol may reduce variability in pathologic assessment. These findings have critical implications considering the impact of margin distance on outcomes.

Oxidized mitochondrial DNA activates the NLRP3 inflammasome during apoptosis.

We report that in the presence of signal 1 (NF-κB), the NLRP3 inflammasome was activated by mitochondrial apoptotic signaling that licensed production of interleukin-1ß (IL-1ß). NLRP3 secondary signal activators such as ATP induced mitochondrial dysfunction and apoptosis, resulting in release of oxidized mitochondrial DNA (mtDNA) into the cytosol, where it bound to and activated the NLRP3 inflammasome. The antiapoptotic protein Bcl-2 inversely regulated mitochondrial dysfunction and NLRP3 inflammasome activation. Mitochondrial DNA directly induced NLRP3 inflammasome activation, because macrophages lacking mtDNA had severely attenuated IL-1ß production, yet still underwent apoptosis. Both binding of oxidized mtDNA to the NLRP3 inflammasome and IL-1ß secretion could be competitively inhibited by the oxidized nucleoside 8-OH-dG. Thus, our data reveal that oxidized mtDNA released during programmed cell death causes activation of the NLRP3 inflammasome. These results provide a missing link between apoptosis and inflammasome activation, via binding of cytosolic oxidized mtDNA to the NLRP3 inflammasome.

Major modifications to minimize thoracic esophago-gastric leak and eradicate esophageal stricture after Ivor Lewis esophagectomy.

BACKGROUND: The Ivor Lewis esophagectomy (ILE) remains the procedure of choice for localized middle or lower esophageal carcinoma. Nevertheless, anastomotic leak remains a common complication with rates from 3% to 25% and a stricture rate as high as 40%. The frequency of these complications suggests that the procedure itself may have inherent limitations including the use of potentially ischemic tissue for the esophagogastric anastomosis. We introduce a modified technique that reduces operative steps, preserves blood supply, and uses a modified esophagogastric anastomosis. METHODS: All consecutive patients undergoing ILE with the described modified technique were identified. An esophagram was performed on postoperative day six or seven. To ensure that all cases were identified, anastomotic leaks were defined as any radiographic evidence of contrast extravasation. RESULTS: A total of 110 patients underwent the modified esophagectomy with 2 anastomotic leaks (1.82%) and zero strictures. There was 1 late death but no early deaths (<30 or 90 days) or early re-admissions (<30 days). The average number of risk factors was 2.12, and 98 patients (90%) had at least 1 risk factor in their medical history. CONCLUSIONS: The modifications proposed simplify procedural steps, limit unnecessary dissection and introduce a technique that ends the practice of connecting ischemic tissue. We believe this technique contributes to surgical durability and reduces the rate of postoperative leak and eliminates stricture.

Preoperative tranexamic acid does not reduce transfusion rates in major oncologic surgery: Results of a randomized, double-blind, and placebo-controlled trial.

BACKGROUND AND OBJECTIVES: Allogeneic blood transfusions are associated with worse postoperative outcomes in oncologic surgery. The aim of this study was to introduce a preoperative intervention to reduce transfusion rates in this population. METHODS: Adult patients undergoing major oncologic surgery in five categories with similar transfusion rates were recruited. Enrollees received a single preoperative intravenous dose of placebo or tranexamic acid (1000 mg). The primary outcome measure was perioperative transfusion rate. Secondary outcome measures included: estimated blood loss, thromboembolic events, morbidity, hospital length of stay, and readmission rate. RESULTS: Seventy-six patients were enrolled, 39 in the tranexamic acid group and 37 in the placebo group, respectively. Demographics and surgery type were equivalent between groups. The transfusion rates were 8 out of 39 (20.5%) in the tranexamic acid group and 5 out of 37 (13.5%) in the placebo group, respectively (P = .418). Median estimated blood loss was 400 mL (interquartile range [IQR] = 150-600) in the tranexamic acid group compared with 300 mL (IQR = 150-800) in the placebo group (P = .983). There was one pulmonary embolism in each arm and no deep venous thrombosis (P > .999). CONCLUSION: Preoperative administration of tranexamic acid at a 1000 mg intravenous dose does not decrease transfusion rates or estimated blood loss in patients undergoing major oncologic surgery.

Prognostic factors of survival in patients with malignant pleural mesothelioma: an analysis of the National Cancer Database.

Malignant pleural mesothelioma (MPM) is a rare disease with a very poor prognosis. Previous studies have indicated that women experience longer survival compared with men. We analyzed 16 267 eligible patients (21.3% females) in the National Cancer Database to evaluate which clinical factors are independently predictive of longer survival. After adjusting for all covariates, survival was significantly better in females compared with males [HRadj: 0.81, 95% confidence interval (CI): 0.77-0.85]. Other factors significantly associated with better survival were younger age at diagnosis, higher income, lower comorbidity score, epithelial histology, earlier stage and receipt of surgical or medical treatment. After propensity matching, survival was significantly better for females compared with males [hazard ratio (HR): 0.86, 95% CI: 0.80-0.94]. After propensity matching within the epithelial group, survival remained significantly better for females compared with males (HR: 0.85, 95% CI: 0.74-0.97). This study adds information to the known significant gender survival difference in MPM by disentangling the effect of gender from the effect of age and histology, two known independent factors affecting survival. Circulating estrogen, present in young but not older women, and higher expression of the estrogen receptor beta in epithelial mesothelioma have been suggested to play a role in gender survival differences. These findings may lead to exploring new therapeutic options, such as targeting estrogen receptor beta, and considering hormonal therapy including estrogens for patients with otherwise limited prognosis.

Mechanistic Basis of Cabotegravir-Glucuronide Disposition in Humans.

Cabotegravir, a novel integrase inhibitor under development for treatment and prevention of HIV, is primarily metabolized by UDP-glucuronosyltransferase (UGT)1A1 and UGT1A9 to a direct ether glucuronide metabolite. The aim of these studies was to elucidate the mechanistic basis of cabotegravir-glucuronide disposition in humans. Cabotegravir glucuronidation was predominantly hepatic (>95%) with minimal intestinal and renal contribution. Rat liver perfusions demonstrated that cabotegravir-glucuronide formed in the liver undergoes comparable biliary and sinusoidal excretion, consistent with high concentrations of the glucuronide in human bile and urine. Cabotegravir-glucuronide biliary excretion was mediated by multidrug resistance-associated protein (MRP)2 (not transported by breast cancer resistance protein or P-glycoprotein), whereas hepatic basolateral excretion into sinusoidal blood was via both MRP3 [fraction transport (Ft) = 0.81] and MRP4 (Ft = 0.19). Surprisingly, despite high urinary recovery of hepatically-formed cabotegravir-glucuronide, metabolite levels in circulation were negligible, a phenomenon consistent with rapid metabolite clearance. Cabotegravir-glucuronide was transported by hepatic uptake transporters organic anion-transporting (OAT) polypeptide (OATP)1B1 and OATP1B3; however, metabolite clearance by hepatic uptake from circulation was low (2.7% of hepatic blood flow) and unable to explain the minimal systemic exposure. Instead, circulating cabotegravir-glucuronide undergoes efficient renal clearance, where uptake into the proximal tubule would be mediated by OAT3 (not transported by OAT1), and subsequent secretion into urine by MRP2 (Ft = 0.66) and MRP4 (Ft = 0.34). These studies provide mechanistic insight into the disposition of cabotegravir-glucuronide, a hepatically-formed metabolite with appreciable urinary recovery and minimal systemic exposure, including fractional contribution of redundant transporters to any given process based on quantitative proteomics. SIGNIFICANCE STATEMENT: The role of membrane transporters in metabolite disposition, especially glucuronides, and as sites of unexpected drug-drug interactions, which alter drug efficacy and safety, has been established. Cabotegravir-glucuronide, formed predominantly by direct glucuronidation of parent drug in liver, was the major metabolite recovered in human urine (27% of oral dose) but was surprisingly not detected in systemic circulation. To our knowledge, this is the first mechanistic description of this phenomenon for a major hepatically-formed metabolite to be excreted in the urine to a large extent, but not circulate at detectable levels. The present study elucidates the mechanistic basis of cabotegravir-glucuronide disposition in humans. Specific hepatic and renal transporters involved in the disposition of cabotegravir-glucuronide, with their fractional contribution, have been provided.

Direct Antimicrobial Activity of IFN-ß.

Type I IFNs are a cytokine family essential for antiviral defense. More recently, type I IFNs were shown to be important during bacterial infections. In this article, we show that, in addition to known cytokine functions, IFN-ß is antimicrobial. Parts of the IFN-ß molecular surface (especially helix 4) are cationic and amphipathic, both classic characteristics of antimicrobial peptides, and we observed that IFN-ß can directly kill Staphylococcus aureus Further, a mutant S. aureus that is more sensitive to antimicrobial peptides was killed more efficiently by IFN-ß than was the wild-type S. aureus, and immunoblotting showed that IFN-ß interacts with the bacterial cell surface. To determine whether specific parts of IFN-ß are antimicrobial, we synthesized IFN-ß helix 4 and found that it is sufficient to permeate model prokaryotic membranes using synchrotron x-ray diffraction and that it is sufficient to kill S. aureus These results suggest that, in addition to its well-known signaling activity, IFN-ß may be directly antimicrobial and be part of a growing family of cytokines and chemokines, called kinocidins, that also have antimicrobial properties.

Systematic review of quality of life following pleurectomy decortication and extrapleural pneumonectomy for malignant pleural mesothelioma.

BACKGROUND: Few studies have focused on quality of life (QoL) after treatment of malignant pleural mesothelioma (MPM). There are still questions as to which surgical procedure, extrapleural pneumonectomy (EPP) or pleurectomy decortication (P/D) is most effective and results in better survival outcomes, involves fewer complications, and results in better QoL. Here we performed a literature review on MPM patients to assess and compare QoL changes after P/D and EPP. METHODS: Research articles concerning QoL after mesothelioma surgery were identified through May 2018 in Medline. For inclusion, studies were 1) cohort or randomized controlled trials (RCT) design, 2) included standardized QoL instruments, 3) reported QoL measurement after surgery, 4) described the type of surgery performed (EPP or P/D), 5) were written in English. Measures of lung function (FEV1, FVC) and measures from the EORTC-C30 were compared 6 months following surgery with preoperative values. RESULTS: QoL data was extracted from 17 articles (14 datasets), encompassing 659 patients (102 EPP, 432 P/D); the available evidence was of low quality. While two studies directly compared QoL between the two surgical procedures, additional data was available from one arm of two RCTs, as the RCTs were not comparing EPP and P/D. The remaining data was reported from observational studies. While QoL was still compromised 6 months following surgery, from the limited and low quality data available it would appear that P/D patients had better QoL than EPP patients across all measures. Physical function, social function and global health were better at follow-up for P/D than for EPP, while other indicators such as pain and cough were similar. Forced Expiratory Volume (FEV1) and Forced Vital Capacity (FVC) were reported in one study only, and were higher at follow-up for P/D compared to EPP. CONCLUSIONS: Although the existing evidence is limited and of low quality, it suggests that P/D patients have better QoL than EPP patients following surgery. QoL outcomes should be factored into the choice of surgical procedure for MPM patients, and the possible effects on lung function and QoL should be discussed with patients when presenting surgical treatment options.

The concerted amyloid-beta clearance of LRP1 and ABCB1/P-gp across the blood-brain barrier is linked by PICALM.

The accumulation of neurotoxic amyloid-beta (Aß) in the brain is a characteristic hallmark of Alzheimer's disease (AD). The blood-brain barrier (BBB) provides a large surface area and has been shown to be an important mediator for removal of brain Aß. Both, the ABC transporter P-glycoprotein (ABCB1/P-gp) and the receptor low-density lipoprotein receptor-related protein 1 (LRP1) have been implicated to play crucial roles in Aß efflux from brain. Here, with immunoprecipitation experiments, co-immunostainings and dual inhibition of ABCB1/P-gp and LRP1, we show that both proteins are functionally linked, mediating a concerted transcytosis of Aß through endothelial cells. Late-onset AD risk factor Phosphatidylinositol binding clathrin assembly protein (PICALM) is associated with both ABCB1/P-gp and LRP1 representing a functional link and guiding both proteins through the brain endothelium. Together, our results give more mechanistic insight on Aß transport across the BBB and show that the functional interplay of different clearance proteins is needed for the rapid removal of Aß from the brain.

Short-term outcomes of pleurectomy decortication and extrapleural pneumonectomy in mesothelioma.

BACKGROUND/OBJECTIVES: We evaluated postoperative mortality and complications after extrapleural pneumonectomy (EPP) and pleurectomy decortication (P/D) to better understand their effectiveness in malignant pleural mesothelioma (MPM). METHODS: A meta-analysis was done to evaluate 30-day mortality and postoperative complications. In addition, in-patients data of 500 eligible patients with MPM who underwent EPP or P/D was extracted from the New York Statewide Planning and Research Cooperative System (SPARCS). Multivariate analyses and propensity matching were used to compare in-hospital mortality and postoperative complications in EPP vs P/D. RESULTS: The meta-analysis showed a statistically significant difference in 30-day mortality (5% [95% CI: 4-6] vs P/D 2% [95% CI: 1-3]), proportion of complications (46% [95% CI: 36-56] vs 24% [95% CI: 15-34]) and postoperative arrhythmias (20% [95% CI: 12-31] vs 5% [95% CI: 2-8]) for EPP vs P/D. In-hospital mortality (OR adj : 2.6; 95% CI: 0.86-7.75) and postoperative complications (OR adj : 1.1; 95% CI: 0.68-1.86) were not different in EPP compared with P/D while supraventricular arrhythmia was significantly more frequent after EPP vs P/D (OR adj : 5.2; 95% CI: 2.34-11.33). CONCLUSIONS: Postoperative mortality, postoperative complications, and particularly supraventricular arrhythmia are less frequent after P/D vs EPP. P/D, a less invasive surgery, may provide a better option when technically feasible for patients with MPM.

Aß40 Reduces P-Glycoprotein at the Blood-Brain Barrier through the Ubiquitin-Proteasome Pathway.

Failure to clear amyloid-ß (Aß) from the brain is in part responsible for Aß brain accumulation in Alzheimer's disease (AD). A critical protein for clearing Aß across the blood-brain barrier is the efflux transporter P-glycoprotein (P-gp) in the luminal plasma membrane of the brain capillary endothelium. P-gp is reduced at the blood-brain barrier in AD, which has been shown to be associated with Aß brain accumulation. However, the mechanism responsible for P-gp reduction in AD is not well understood. Here we focused on identifying critical mechanistic steps involved in reducing P-gp in AD. We exposed isolated rat brain capillaries to 100 nm Aß40, Aß40, aggregated Aß40, and Aß42. We observed that only Aß40 triggered reduction of P-gp protein expression and transport activity levels; this occurred in a dose- and time-dependent manner. To identify the steps involved in Aß-mediated P-gp reduction, we inhibited protein ubiquitination, protein trafficking, and the ubiquitin-proteasome system, and monitored P-gp protein expression, transport activity, and P-gp-ubiquitin levels. Thus, exposing brain capillaries to Aß40 triggers ubiquitination, internalization, and proteasomal degradation of P-gp. These findings may provide potential therapeutic targets within the blood-brain barrier to limit P-gp degradation in AD and improve Aß brain clearance. SIGNIFICANCE STATEMENT: The mechanism reducing blood-brain barrier P-glycoprotein (P-gp) in Alzheimer's disease is poorly understood. In the present study, we focused on defining this mechanism. We demonstrate that Aß40 drives P-gp ubiquitination, internalization, and proteasome-dependent degradation, reducing P-gp protein expression and transport activity in isolated brain capillaries. These findings may provide potential therapeutic avenues within the blood-brain barrier to limit P-gp degradation in Alzheimer's disease and improve Aß brain clearance.

Activation of the innate immune receptor Dectin-1 upon formation of a 'phagocytic synapse'.

Innate immune cells must be able to distinguish between direct binding to microbes and detection of components shed from the surface of microbes located at a distance. Dectin-1 (also known as CLEC7A) is a pattern-recognition receptor expressed by myeloid phagocytes (macrophages, dendritic cells and neutrophils) that detects ß-glucans in fungal cell walls and triggers direct cellular antimicrobial activity, including phagocytosis and production of reactive oxygen species (ROS). In contrast to inflammatory responses stimulated upon detection of soluble ligands by other pattern-recognition receptors, such as Toll-like receptors (TLRs), these responses are only useful when a cell comes into direct contact with a microbe and must not be spuriously activated by soluble stimuli. In this study we show that, despite its ability to bind both soluble and particulate ß-glucan polymers, Dectin-1 signalling is only activated by particulate ß-glucans, which cluster the receptor in synapse-like structures from which regulatory tyrosine phosphatases CD45 and CD148 (also known as PTPRC and PTPRJ, respectively) are excluded (Supplementary Fig. 1). The 'phagocytic synapse' now provides a model mechanism by which innate immune receptors can distinguish direct microbial contact from detection of microbes at a distance, thereby initiating direct cellular antimicrobial responses only when they are required.