Mutated Toll-like receptor 9 increases Alzheimer's disease risk by compromising innate immunity protection.

The development of Alzheimer's disease (AD) involves central and peripheral immune deregulation. Gene identification and studies of AD genetic variants of peripheral immune components may aid understanding of peripheral-central immune crosstalk and facilitate new opportunities for therapeutic intervention. In this study, we have identified in a Flanders-Belgian family a novel variant p.E317D in the Toll-like receptor 9 gene (TLR9), co-segregating with EOAD in an autosomal dominant manner. In human, TLR9 is an essential innate and adaptive immune component predominantly expressed in peripheral immune cells. The p.E317D variant caused 50% reduction in TLR9 activation in the NF-κB luciferase assay suggesting that p.E317D is a loss-of-function mutation. Cytokine profiling of human PBMCs upon TLR9 activation revealed a predominantly anti-inflammatory response in contrast to the inflammatory responses from TLR7/8 activation. The cytokines released upon TLR9 activation suppressed inflammation and promoted phagocytosis of Aß42 oligomers in human iPSC-derived microglia. Transcriptome analysis identified upregulation of AXL, RUBICON and associated signaling pathways, which may underline the effects of TLR9 signaling-induced cytokines in regulating the inflammatory status and phagocytic property of microglia. Our data suggest a protective role of TLR9 signaling in AD pathogenesis, and we propose that TLR9 loss-of-function may disrupt a peripheral-central immune crosstalk that promotes dampening of inflammation and clearance of toxic protein species, leading to the build-up of neuroinflammation and pathogenic protein aggregates in AD development.

Role of imbalanced gut microbiota in promoting CRC metastasis: from theory to clinical application.

Metastasis poses a major challenge in colorectal cancer (CRC) treatment and remains a primary cause of mortality among patients with CRC. Recent investigations have elucidated the involvement of disrupted gut microbiota homeostasis in various facets of CRC metastasis, exerting a pivotal influence in shaping the metastatic microenvironment, triggering epithelial-mesenchymal transition (EMT), and so on. Moreover, therapeutic interventions targeting the gut microbiota demonstrate promise in enhancing the efficacy of conventional treatments for metastatic CRC (mCRC), presenting novel avenues for mCRC clinical management. Grounded in the "seed and soil" hypothesis, this review consolidates insights into the mechanisms by which imbalanced gut microbiota promotes mCRC and highlights recent strides in leveraging gut microbiota modulation for the clinical prevention and treatment of mCRC. Emphasis is placed on the considerable potential of manipulating gut microbiota within clinical settings for managing mCRC.

The value of intratumoral microbiota in the diagnosis and prognosis of tumors.

Intratumoral microbiota (ITM) are microorganisms present in tumor cells. ITM participate in tumor development by affecting tumor cells directly and the tumor microenvironment (TME), indirectly. Alterations in ITM instigate changes in tumor DNA, activate oncogenic pathways, induce tumor inflammatory responses, disrupt normal immune activity, and facilitate the secretion of effectors leading to tumor progression, metastasis, or diminished therapeutic effects. ITM varies significantly in different types of cancer cells and disease states. The presence of certain ITM serves as a predictor of various disease states. Thus, ITM predicts tumorigenesis, tumor grade, treatment efficacy, and prognosis, making it a potential tumor biomarker. The present study aimed to determine the mechanisms by which ITM affects tumor development, especially through the TME; highlight the significant potential of ITM in enhancing tumor diagnosis and prognosis; and outline future directions for ITM research, with a focus on the development of innovative tumor markers.

Single-cell transcriptomic analysis reveals the immune landscape of lung in steroid-resistant asthma exacerbation.

Exaggerated airway hyperresponsiveness and inflammation are hallmarks of asthma, and lipopolysaccharide (LPS) exposure is linked to the severity of the disease and steroid resistance. To investigate the mechanisms underlying asthma exacerbation, we established a mouse model of LPS-induced steroid-resistant exacerbation on the background of house dust mite (HDM)-induced asthma to profile the immune cells in lung by using single-cell RNA deep sequencing. Twenty immune subsets were identified by their molecular and functional properties. Specific cell clusters of basophils, type 2 innate lymphoid cells (ILC2), and CD8+ memory T cells were the predominant sources of interleukin (IL)-4 and IL-13 transcripts whose expressions were dexamethasone resistant. Production of IL-13 by these cells was validated by IL-13-reporter mice. Neutralization of IL-13 abolished HDM/LPS-induced airway hyperresponsiveness, airway inflammation, and decreased mucus hypersecretion. Furthermore, using Ingenuity Pathway Analysis systems, we identified canonical pathways and upstream regulators that regulate the activation of basophils, ILC2, and CD8+ memory T cells. Our study provides mechanistic insights and an important reference resource for further understanding of the immune landscape during asthma exacerbation.

Single-cell transcriptomic analysis reveals key immune cell phenotypes in the lungs of patients with asthma exacerbation.

BACKGROUND: Asthma exacerbations are associated with heightened asthma symptoms, which can result in hospitalization in severe cases. However, the molecular immunologic processes that determine the course of an exacerbation remain poorly understood, impeding the progression of development of effective therapies. OBJECTIVE: Our aim was to identify candidate genes that are strongly associated with asthma exacerbation at a cellular level. METHODS: Subjects with asthma exacerbation and healthy control subjects were recruited, and bronchoalveolar lavage fluid was isolated from these subjects via bronchoscopy. Cells were isolated through fluorescence-activated cell sorting, and single-cell RNA sequencing was performed on enriched cell populations. RESULTS: We showed that the levels of monocytes, CD8+ T cells, and macrophages are significantly elevated in the bronchoalveolar lavage fluid of patients. A set of cytokines and intracellular transduction regulators are associated with asthma exacerbations and are shared across multiple cell clusters, forming a complicated molecular framework. An additional group of core exacerbation-associated modules is activated, including eukaryotic initiation factor 2 signaling, ephrin receptor signaling, and C-X-C chemokine receptor type 4 signaling in the subpopulations of CD8+ T cells (C1-a) and monocyte clusters (C7 clusters), which are associated with infection. CONCLUSION: Our study identified a significant number of severe asthma-associated genes that are differentially expressed by multiple cell clusters.

Research progress of mesenchymal stem cell-derived exosomes on inflammatory response after ischemic stroke.

Ischemic stroke is characterized by cute onset and high mortality. The suppression of neuroinflammation is crucial in the treatment of ischemic stroke. Exosomes derived from mesenchymal stem cell (MSC) have attracted extensive research attention due to their wide origin, small size, and containing large number of active components. Recent studies have shown that MSC-derived exosomes can inhibit the proinflammatory activity of microglia and astrocytes and stimulate their neuroprotective activity; also can inhibit neuroinflammation by regulating immune cells and inflammatory mediators. This article reviews the roles and related mechanism of MSC-derived exosomes in neuroinflammation after ischemic stroke, hoping to provide ideas and references for the development of a novel approach for the treatment of ischemic stroke diseases.

Role of initial chirp and dispersion on Airy pulse propagation in an optical single-mode fiber.

We study numerically the propagation dynamics of an initially finite-energy chirped Airy pulse in an optical single-mode fiber when the group-velocity dispersion parameter ß2 and chirp C have opposite signs. The different chirp parameters of the Airy pulse represent a special spectrum that improves the propagation. For ß2C<0, the chirped Airy pulse forms a weak breakup area. We found the change rule of the main lobe and peak intensity with the pulse propagation distance and the position of the breakup area in order to understand the importance of the initial pulse chirp. The impact of chirp and self-phase modulation to the Airy pulse is discussed.

Impact of erenumab on acute medication usage and health care resource utilization among migraine patients: a US claims database study.

BACKGROUND: Migraine is one of the leading causes of disability worldwide. Erenumab is a fully human monoclonal antibody that targets the calcitonin gene-related peptide (CGRP) receptor. This study aimed to evaluate real-world evidence on the impact of erenumab on acute medication usage and health care resource utilization (HCRU) among migraine patients. METHODS: This retrospective effectiveness study utilized the US Optum's de-identified Clinformatics® Data Mart database to identify migraine patients initiating erenumab between May 1, 2018 and September 30, 2019. Patients had to be at least 18 years old, with a minimum of three doses for erenumab in the 6-month post-index period and continuous medical/pharmacy coverage in the 12-month pre- and 6-month post-index period. The date of the first claim for erenumab served as the index date. Use of acute medications overall and at different drug class level, and HCRU were compared during the 6-month pre- vs. post-index period. Impact of erenumab on a composite endpoint of three possible events: 1) outpatient visit with a diagnosis of migraine and an associated acute medication claim within 7 days of the visit, 2) hospital admission with a primary diagnosis for migraine, or 3) emergency room visit with a primary diagnosis for migraine (any events that occurred ≤3 days apart were counted only once) was also evaluated. RESULTS: The analysis included 3171 identified patients. At 6 months, following initiation of erenumab, acute medication use including the number of types of acute medication, number of claims of each medication and % of patients who received acute medication, and HCRU were significantly decreased. For the composite outcome, the mean number of events decreased from 1.03 to 0.77 (rate ratio: 0.75; 95% CI: 0.71 to 0.79; P < 0.0001). A decrease in the proportion of patients with any of the three events was also observed (52.7% vs. 39.5%, P < 0.0001). CONCLUSION: In this retrospective analysis, erenumab was associated with significantly reduced acute medication use and HCRU in a real-world setting, hence significantly reducing the burden of the disease. A composite endpoint could be used as a proxy to evaluate the burden of migraine attacks; however, further research is needed.

Enantioselective Difunctionalization of Alkenes by a Palladium-Catalyzed Heck/Sonogashira Sequence.

Sonogashira-type cross-couplings are one of the most significant alkynylations in organic chemistry. One of the first palladium-catalyzed intramolecular Heck/Sonogashira reactions of alkenes with terminal alkynes is now reported. With this method, a variety of uniquely substituted chiral benzene-fused heterocycles bearing a propargyl-substituted all-carbon quaternary stereocenter were obtained in a straightforward, high-yielding, and highly stereoselective manner under mild conditions. Salient features of this process include the use of readily available substrates, high selectivities, a broad substrate scope as well as versatile product functionalizations.

Palladium/XuPhos-Catalyzed Enantioselective Carboiodination of Olefin-Tethered Aryl Iodides.

A highly enantioselective palladium-catalyzed iodine atom transfer cycloisomerization of unactivated alkenes has been developed. This represents the first example of highly enantioselective carboiodination of olefin-tethered aryl iodides, which provides a perfect atom economy method to construct a series of optically active 2,3-dihydrobenzofuran, indolines and chromane bearing an alkyl iodide group in moderate to good yields. Moreover, the use of readily available starting materials, a broad substrate scope, high selectivity, mild reaction conditions, as well as versatile transformation of the product make this approach attractive. The mechanism of this Pd(0)-catalyzed asymmetric carboiodination of alkenes has been investigated with density functional theory.

Hospital volume and mortality after transjugular intrahepatic portosystemic shunt creation in the United States.

The link between higher procedure volume and better outcomes for surgical procedures is well established. We aimed to determine whether procedure volume affected inpatient mortality in patients undergoing transjugular intrahepatic portosystemic shunt (TIPS). An epidemiological analysis of an all-payer database recording hospitalizations during 2013 in the United States (Nationwide Readmissions Database) was performed. All patients ≥ 18 years old undergoing TIPS during a hospital admission (n = 5529) without concurrent or prior liver transplantation were selected. All-cause inpatient mortality was assessed. Risk-adjusted mortality was assessed for hospitals categorized into quintiles based on annual TIPS volume (very low, 1-4/year; low, 5-9/year; medium, 10-19/year; high, 20-29/year; and very high, ≥ 30/year). TIPS were placed in all 5529 patients (mean age, 57 years [standard deviation, ± 10.9 years]; women, n = 2071; men, n = 3458). Mortality decreased with rising annual TIPS volume (13% for very low to 6% for very high volume hospitals; P < 0.01). Elective admissions were more common in hospitals with higher annual TIPS volume (20.3% for very low to 30.8% for very high; P < 0.01). On multivariate analysis, compared with hospitals performing ≥30 TIPS per year, only hospitals performing 1-4/year (adjusted odds ratio [aOR], 1.9; 95% confidence interval [CI], 1.21-3.01; P = 0.01), 5-9/year (aOR, 2.0; 95% CI, 1.25-3.17; P < 0.01), and 10-19/year (aOR, 1.9; 95% CI, 1.17-3.00; P = 0.01) had higher inpatient mortality (20-29/year: aOR, 1.4; 95% CI, 0.84-2.84; P = 0.19). The absolute difference between risk-adjusted mortality rate for very low volume and very high volume hospitals was 6.1% (13.9% versus 7.8%). TIPS volume of ≤ 20 TIPS/year, variceal bleeding, and nosocomial infections were independent risk factors for inpatient mortality in patients with both elective and emergent admissions. Conclusion: The risk of inpatient mortality is lower in hospitals performing ≥20 TIPS per year. Future research exploring preventable factors for higher mortality and benefits of patient transfer to higher volume centers is warranted. (Hepatology 2018;67:690-699).

Enantioselective Dicarbofunctionalization of Unactivated Alkenes by Palladium-Catalyzed Tandem Heck/Suzuki Coupling Reaction.

A highly enantioselective dicarbofunctionalization of unactivated alkenes was implemented by a Pd-catalyzed asymmetric tandem Heck/Suzuki coupling reaction. This reaction represents the first example of a highly enantioselective intramolecular cyclization/cross-coupling of olefin-tethered aryl halides with alkyl-, alkenyl- or arylboronic acids, and provides rapid access to a number of chiral compounds, such as dihydrobenzofurans, indolines, chromanes, and indanes bearing a quaternary stereocenter, in good yields with excellent enantioselectivities. The practicality of this reaction was validated in the modification of biologically complex molecules such as peptides, piperitol, CB2 receptor agonists, etc. Moreover, the synthesis of two enantiomers can be easily realized by simple change in the order of the steps in the coupling sequence.

Palladium-Catalyzed Enantioselective Reductive Heck Reactions: Convenient Access to 3,3-Disubstituted 2,3-Dihydrobenzofuran.

The first example of highly enantioselective intramolecular hydroarylation of allyl aryl ethers was realized by palladium-catalyzed reductive heck reactions utilizing a new chiral sulfinamide phosphine ligand (N-Me-XuPhos). N-Me-XuPhos can be easily prepared on gram scale from readily available starting materials in a one-pot synthesis approach. A series of optically active 2,3-dihydrobenzofurans bearing a quaternary stereocenter were obtained in good yields and with excellent enantioselectivities. The practicality of this reaction was validated in the straightforward synthesis of CB2 receptor agonists. Moreover, deuterium was efficiently incorporated into the products.

The Relevance of Readmissions after Common IR Procedures: Readmission Rates and Association with Early Mortality.

PURPOSE: To determine all-cause readmission rates for 12 IR procedures and association of time to readmission with risk-adjusted 90-day mortality. MATERIALS AND METHODS: Patients discharged after 12 inpatient IR procedures at a tertiary-care hospital between June 2008 and May 2013 (N = 4,163) were categorized as no readmission (n = 1,479; 40.5%) or readmission between 0 and 7 (n = 379; 10.4%), 8 and 30 (n = 650; 17.8%), 31 and 60 (n = 378; 10.3%), 61 and 90 (n = 169; 4.6%), or 91 and 180 days (n = 280; 7.7%). Readmission rate ≥ 15% was considered high based on published national readmission rates for procedures. Risk-adjusted 90-day mortality for each interval was calculated for transjugular intrahepatic portosystemic shunt (TIPS), transjugular and percutaneous liver biopsy (TJLB, PLB), ports, inferior vena cava (IVC) filter, lower extremity angioplasty (LEA), arteriovenous fistulagrams, vascular embolization (VE), percutaneous cholecystostomy (PC), percutaneous transhepatic biliary drainage (PTBD), primary urinary drainage, and feeding tube placement. Covariates included age, sex, race, insurance status, and Charlson Comorbidity Index. RESULTS: All procedures had high 30-day readmission rates (15%-50.5%). Readmissions were highest for ports (50.5%), TJLB (43.4%), PTBD (38.5%), PC (31.9%), and TIPS (31.3%). Readmissions occurred most frequently 8-30 days after discharge for all procedures except VE (31-60 d; 10.6%), PC (31-60 d; 23.4%), and LEA (91-180 d; 15.1%). On multivariate analysis, 30-day readmissions for LEA (AOR 3.19; 95% CI, 1.2-8.2; P = .02), VE (AOR 10.01; 95% CI, 3.1-32.9; P < .001), IVC filter (AOR 2.98; 95% CI, 1.3-6.9; P = .01), PLB (AOR 2.86; 95% CI, 1.71-4.79; P < .001), and PCN (AOR 3.09; 95% CI, 1.29-7.37; P = .01) were associated with 90-day mortality. CONCLUSIONS: Inpatient IR procedures have high 30-day all-cause readmission rates, which can be associated with increased 90-day mortality. Further evaluation to determine preventable causes for readmission may impact 90-day mortality.

The mechanism of γ-Secretase dysfunction in familial Alzheimer disease.

The mechanisms by which mutations in the presenilins (PSEN) or the amyloid precursor protein (APP) genes cause familial Alzheimer disease (FAD) are controversial. FAD mutations increase the release of amyloid ß (Aß)42 relative to Aß40 by an unknown, possibly gain-of-toxic-function, mechanism. However, many PSEN mutations paradoxically impair γ-secretase and 'loss-of-function' mechanisms have also been postulated. Here, we use kinetic studies to demonstrate that FAD mutations affect Aß generation via three different mechanisms, resulting in qualitative changes in the Aß profiles, which are not limited to Aß42. Loss of ɛ-cleavage function is not generally observed among FAD mutants. On the other hand, γ-secretase inhibitors used in the clinic appear to block the initial ɛ-cleavage step, but unexpectedly affect more selectively Notch than APP processing, while modulators act as activators of the carboxypeptidase-like (γ) activity. Overall, we provide a coherent explanation for the effect of different FAD mutations, demonstrating the importance of qualitative rather than quantitative changes in the Aß products, and suggest fundamental improvements for current drug development efforts.

Merging Chiral Brønsted Acid/Base Catalysis: An Enantioselective [4 + 2] Cycloaddition of o-Hydroxystyrenes with Azlactones.

An enantioselective [4 + 2] cycloaddition of o-hydroxylstyrenes with azlactones has been established by merging chiral Brønsted acid (chiral phosphoric acid) and base (chiral guanidine) catalysis, which constructed a biologically important dihydrocoumarin scaffold in an efficient and enantioselective style (up to 99% yield, 96:4 er). This approach has not only realized the successful application of o-hydroxylstyrenes as oxa-diene precursors in catalytic asymmetric cycloadditions but also established a new cooperative catalytic system of chiral phosphoric acid and chiral guanidine.

Organocatalytic arylation of 3-indolylmethanols via chemo- and regiospecific C6-functionalization of indoles.

An organocatalytic arylation of 3-indolylmethanols has been established via chemo- and regiospecific C6-functionalization of 2,3-disubstituted indoles, leading to the production of bisindolyloxindoles containing an all-carbon quaternary stereocenter in high yields (up to 99% yield). This reaction not only represents the first catalytic arylation of 3-indolylmethanols using 2,3-disubstituted indoles as aromatic nucleophiles but also serves as a good example of direct catalytic C6-functionalization of indoles, which have been scarcely investigated. Besides, this approach also provides an efficient method to access a biologically important 3,3'-disubstituted oxindole framework and a 3',6-linked bisindole skeleton. Furthermore, the investigation of the activation mode suggested that the dual activation of an ion pair and H-bond between the substrates and the catalyst cooperatively contributed to the success of the reaction.

ADP ribosylation factor 6 (ARF6) controls amyloid precursor protein (APP) processing by mediating the endosomal sorting of BACE1.

Amyloid ß (Aß) peptides, the primary constituents of senile plaques and a hallmark in Alzheimer's disease pathology, are generated through the sequential cleavage of amyloid precursor protein (APP) by ß-site APP cleaving enzyme 1 (BACE1) and γ-secretase. The early endosome is thought to represent a major compartment for APP processing; however, the mechanisms of how BACE1 encounters APP are largely unknown. In contrast to APP internalization, which is clathrin-dependent, we demonstrate that BACE1 is sorted to early endosomes via a route controlled by the small GTPase ADP ribosylation factor 6 (ARF6). Altering ARF6 levels or its activity affects endosomal sorting of BACE1, and consequently results in altered APP processing and Aß production. Furthermore, sorting of newly internalized BACE1 from ARF6-positive towards RAB GTPase 5 (RAB5)-positive early endosomes depends on its carboxyterminal short acidic cluster-dileucine motif. This ARF6-mediated sorting of BACE1 is confined to the somatodendritic compartment of polarized neurons in agreement with Aß peptides being primarily secreted from here. These results demonstrate a spatial separation between APP and BACE1 during surface-to-endosome transport, suggesting subcellular trafficking as a regulatory mechanism for this proteolytic processing step. It thereby provides a novel avenue to interfere with Aß production through a selective modulation of the distinct endosomal transport routes used by BACE1 or APP.

Symbiotic microbial communities in various locations of the lung cancer respiratory tract along with potential host immunological processes affected.

Lung cancer has the highest mortality rate among all cancers worldwide. The 5-year overall survival rate for non-small cell lung cancer (NSCLC) is estimated at around 26%, whereas for small cell lung cancer (SCLC), the survival rate is only approximately 7%. This disease places a significant financial and psychological burden on individuals worldwide. The symbiotic microbiota in the human body has been significantly associated with the occurrence, progression, and prognosis of various diseases, such as asthma, chronic obstructive pulmonary disease (COPD), and cystic fibrosis. Studies have demonstrated that respiratory symbiotic microorganisms and their metabolites play a crucial role in modulating immune function and contributing to the pathophysiology of lung cancer through their interactions with the host. In this review, we provide a comprehensive overview of the microbial characteristics associated with lung cancer, with a focus on the respiratory tract microbiota from different locations, including saliva, sputum, bronchoalveolar lavage fluid (BALF), bronchial brush samples, and tissue. We describe the respiratory tract microbiota's biodiversity characteristics by anatomical region, elucidating distinct pathological features, staging, metastasis, host chromosomal mutations, immune therapies, and the differentiated symbiotic microbiota under the influence of environmental factors. Our exploration investigates the intrinsic mechanisms linking the microbiota and its host. Furthermore, we have also provided a comprehensive review of the immune mechanisms by which microbiota are implicated in the development of lung cancer. Dysbiosis of the respiratory microbiota can promote or inhibit tumor progression through various mechanisms, including DNA damage and genomic instability, activation and regulation of the innate and adaptive immune systems, and stimulation of epithelial cells leading to the upregulation of carcinogenesis-related pathways.

Microbes in the tumor microenvironment: New additions to break the tumor immunotherapy dilemma.

Immunotherapies currently used in clinical practice are unsatisfactory in terms of therapeutic response and toxic side effects, and therefore new immunotherapies need to be explored. Intratumoral microbiota (ITM) exists in the tumor environment (TME) and reacts with its components. On the one hand, ITM promotes antigen delivery to tumor cells or provides cross-antigens to promote immune cells to attack tumors. On the other hand, ITM affects the activity of immune cells and stromal cells. We also summarize the dialog pathways by which ITM crosstalks with components within the TME, particularly the interferon pathway. This interaction between ITM and TME provides new ideas for tumor immunotherapy. By analyzing the bidirectional role of ITM in TME and combining it with its experimental and clinical status, we summarized the adjuvant role of ITM in immunotherapy. We explored the potential applications of using ITM as tumor immunotherapy, such as a healthy diet, fecal transplantation, targeted ITM, antibiotics, and probiotics, to provide a new perspective on the use of ITM in tumor immunotherapy.