Mechanism of an intramembrane chaperone for multipass membrane proteins.

Multipass membrane proteins play numerous roles in biology and include receptors, transporters, ion channels and enzymes1,2. How multipass proteins are co-translationally inserted and folded at the endoplasmic reticulum is not well understood2. The prevailing model posits that each transmembrane domain (TMD) of a multipass protein successively passes into the lipid bilayer through a front-side lateral gate of the Sec61 protein translocation channel3-9. The PAT complex, an intramembrane chaperone comprising Asterix and CCDC47, engages early TMDs of multipass proteins to promote their biogenesis by an unknown mechanism10. Here, biochemical and structural analysis of intermediates during multipass protein biogenesis showed that the nascent chain is not engaged with Sec61, which is occluded and latched closed by CCDC47. Instead, Asterix binds to and redirects the substrate to a location behind Sec61, where the PAT complex contributes to a multipass translocon surrounding a semi-enclosed, lipid-filled cavity11. Detection of multiple TMDs in this cavity after their emergence from the ribosome suggests that multipass proteins insert and fold behind Sec61. Accordingly, biogenesis of several multipass proteins was unimpeded by inhibitors of the Sec61 lateral gate. These findings elucidate the mechanism of an intramembrane chaperone and suggest a new framework for multipass membrane protein biogenesis at the endoplasmic reticulum.

Structural insights into ClpP protease side exit pore-opening by a pH drop coupled with substrate hydrolysis.

The ClpP serine peptidase is a tetradecameric degradation molecular machine involved in many physiological processes. It becomes a competent ATP-dependent protease when coupled with Clp-ATPases. Small chemical compounds, acyldepsipeptides (ADEPs), are known to cause the dysregulation and activation of ClpP without ATPases and have potential as novel antibiotics. Previously, structural studies of ClpP from various species revealed its structural details, conformational changes, and activation mechanism. Although product release through side exit pores has been proposed, the detailed driving force for product release remains elusive. Herein, we report crystal structures of ClpP from Bacillus subtilis (BsClpP) in unforeseen ADEP-bound states. Cryo-electron microscopy structures of BsClpP revealed various conformational states under different pH conditions. To understand the conformational change required for product release, we investigated the relationship between substrate hydrolysis and the pH-lowering process. The production of hydrolyzed peptides from acidic and basic substrates by proteinase K and BsClpP lowered the pH values. Our data, together with those of previous findings, provide insight into the molecular mechanism of product release by the ClpP self-compartmentalizing protease.

Crystal structure of the Ate1 arginyl-tRNA-protein transferase and arginylation of N-degron substrates.

N-degron pathways are proteolytic systems that target proteins bearing N-terminal (Nt) degradation signals (degrons) called N-degrons. Nt-Arg of a protein is among Nt-residues that can be recognized as destabilizing ones by the Arg/N-degron pathway. A proteolytic cleavage of a protein can generate Arg at the N terminus of a resulting C-terminal (Ct) fragment either directly or after Nt-arginylation of that Ct-fragment by the Ate1 arginyl-tRNA-protein transferase (R-transferase), which uses Arg-tRNAArg as a cosubstrate. Ate1 can Nt-arginylate Nt-Asp, Nt-Glu, and oxidized Nt-Cys* (Cys-sulfinate or Cys-sulfonate) of proteins or short peptides. Ate1 genes of fungi, animals, and plants have been cloned decades ago, but a three-dimensional structure of Ate1 remained unknown. A detailed mechanism of arginylation is unknown as well. We describe here the crystal structure of the Ate1 R-transferase from the budding yeast Kluyveromyces lactis. The 58-kDa R-transferase comprises two domains that recognize, together, an acidic Nt-residue of an acceptor substrate, the Arg residue of Arg-tRNAArg, and a 3'-proximal segment of the tRNAArg moiety. The enzyme's active site is located, at least in part, between the two domains. In vitro and in vivo arginylation assays with site-directed Ate1 mutants that were suggested by structural results yielded inferences about specific binding sites of Ate1. We also analyzed the inhibition of Nt-arginylation activity of Ate1 by hemin (Fe3+-heme), and found that hemin induced the previously undescribed disulfide-mediated oligomerization of Ate1. Together, these results advance the understanding of R-transferase and the Arg/N-degron pathway.

Comparison of Outcomes in Bowel Resections by Gynecologic Oncologists Versus General Surgeons During Maximal Cytoreductive Surgery for Advanced Ovarian Cancer: Gynecologic Oncology Research Investigators Collaboration Study (GORILLA-3006).

BACKGROUND: This report describes the oncologic outcomes for patients with advanced ovarian cancer who had bowel surgery performed by gynecologic oncologists (GOs) and compares the outcomes with those for bowel surgery performed by general surgeons (GSs) during maximal cytoreductive surgery. METHODS: Patients from six academic institutions who had FIGO stage III or IV ovarian cancer and underwent any bowel surgeries during maximal cytoreductive surgery were eligible for the study. The patients were divided into two groups according to whether bowel surgery was performed by a GO or a GS. In both groups, the GOs were mainly involved in extra bowel debulking procedures. Perioperative and survival outcomes were compared between the two groups. RESULTS: The 761 patients in this study included 113 patients who underwent bowel surgery by a GO and 648 who had bowel surgery by a GS. No discernible differences were observed in age, American Society of Anesthesiology (ASA) score, FIGO stage, histologic type, timing of cytoreductive surgery (primary or interval debulking surgery), or complications between the two groups. The GO group exhibited a shorter operation time than the GS group. Kaplan-Meier analysis showed no survival differences between the two groups. In the Cox analysis, non-serous cell types and gross residual diseases were associated with adverse effects on overall survival. However, performance of bowel surgery by a GO did not have an impact on survival. CONCLUSION: Performance of bowel surgery by a GO during maximal cytoreductive surgery is both feasible and safe. These results should be reflected in the training system for GOs regarding bowel surgery, and further research is needed to confirm that GOs can play a more leading role in performing extra-uterine procedures.

Polydopamine-Coated Silk Fiber with Controllable Length for Enhanced Hemostatic Application.

The development of highly effective hemostatic materials with high biocompatibility and outstanding performance is vital to the field of biomaterials. In this study, we develop a hemostatic fiber material that exhibits high biocompatibility and excellent performance. By incorporating polydopamine (PDA) into the alkaline treatment of silk fibroin (SF), we achieve PDA-coated SF fibers with lengths that can be controlled by the alkaline concentration. The PDA coating significantly enhances the hemostatic ability of the silk fibers and exhibits superior performance in both in vitro and ex vivo experiments. By performing animal studies involving a mouse liver puncture model and a femoral vein incision model, we demonstrate the remarkable hemostatic capability of the PDA-coated SF fibers, as evidenced by the lower blood loss compared to that of a commercial hemostat powder. These findings highlight the potential of applying a PDA-assisted alkaline treatment to SF fibers to efficiently create hemostatic fibers with controllable lengths, which would be promising candidates for clinical hemostatic applications.

Propensity score matched analysis for the safety and effectiveness of remdesivir in COVID-19 patients with renal impairment.

BACKGROUNDS: Remdesivir (RDV) is an antiviral agent approved for the treatment of coronavirus disease 2019 (COVID-19); however, is not recommended for patients with renal impairment. Due to limitations associated with prospective clinical trials, real-world data on the safety and efficacy of RDV in patients with renal impairment are necessary. METHODS: Propensity score-matched (PSM) retrospective analysis was conducted between March 2020 and September 2022 in COVID-19 patients with an eGFR < 30 mL/min in four Korean hospitals. The RDV treatment group was matched to the untreated control group. The safety and clinical outcomes in patients who received RDV were analyzed. RESULTS: A total of 564 patients were enrolled; 229 patients received RDV either for treatment or prophylaxis. On day 5, no difference in nephrotoxicity was observed between the two groups, and liver enzyme levels were within the normal range. In multivariate analysis for new dialysis, RDV treatment was not a risk factor for new dialysis. Among the 564 patients, 417 were indicated for a 5-day course of RDV treatment and 211 patients were treated with RDV. After PSM, no differences in the clinical outcomes were observed between the two groups. CONCLUSION: RDV use in COVID-19 patients with renal impairment did not result in significant nephrotoxicity or hepatotoxicity.

Association between Tobacco Industry Interference Index (TIII) and MPOWER measures and adult daily smoking prevalence rate in 30 countries.

BACKGROUND: This study aimed to investigate the impact of tobacco industry interference on the implementation and management of tobacco control and the tobacco epidemic using the Tobacco Industry Interference Index (TIII) and MPOWER-a package of measures for tobacco control-and adult daily smoking prevalence in 30 countries. METHODS: The TIII was extracted from the Global Tobacco Industry Interference Index 2019 and Global Center for Good Governance in Tobacco Control (GGTC). MPOWER measures and adult daily smoking prevalence rate were extracted from the World Health Organization (WHO) report on the global tobacco epidemic in 2021. We assessed the ecological cross-lagged association between TIII and MPOWER scores and between TIII and age-standardized prevalence rates for adult daily tobacco users. RESULTS: Tobacco industry interference was inversely correlated with a country's package of tobacco control measures (ß = -0.088, P = 0.035). The TIII was correlated with weaker warnings about the dangers of tobacco (ß = -0.016, P = 0.078) and lack of enforcement of bans on tobacco advertising promotion and sponsorship (ß = -0.023, P = 0.026). In turn, the higher the TIII, the higher the age-standardized prevalence of adult daily tobacco smokers for both sexes (ß = 0.170, P = 0.036). Adult daily smoking prevalence in males (ß = 0.417, P = 0.004) was higher in countries where the tobacco industry received incentives that benefited its business. CONCLUSION: Where the interference of the tobacco industries was high, national compliance with the Framework Convention on Tobacco Control (FCTC) was lower, and the prevalence of adult daily smokers higher. National governments and global society must work together to minimize the tobacco industry's efforts to interfere with tobacco control policies.

Severe mpox requiring colostomy in a patient with advanced HIV disease: a case report and literature review.

This severe monkeypox case described a 23-year-old male with advanced HIV-1 disease presenting perirectal abscess, extensive anal ulcerative lesions requiring colostomy, and tecovirimat resistance. Radiologically non-liquefied perirectal abscess presented diagnostic challenges highlighting the complexity of aggressive monkeypox manifestations in immunocompromised individuals.

Adverse Reactions After Intradermal Vaccination With JYNNEOS for Mpox in Korea.

In response to the Mpox domestic epidemic, South Korea initiated a nationwide vaccination program in May 2023, administering a 0.1 mL intradermal dose of JYNNEOS (Modified Vaccinia Ankara vaccine, Bavarian Nordic) to a high-risk group. To investigate the adverse reactions after intradermal JYNNEOS vaccination, an anonymous online survey was conducted at the National Medical Center from May 22 to July 31, 2023. Overall, 142 individuals responded. Over 80% of the respondents reported local reactions of predominantly mild severity. The predominant local reactions were pruritus, redness, and swelling; their incidence rates after the first dose were 66.2%, 48.1%, and 49.4%, respectively; the corresponding rates after the second dose were 69.2%, 60.6%, and 53.8%. Fewer respondents reported systemic symptoms. The most common systemic symptom was fatigue, the incidence rates of which after the first and second doses were 37.7% and 24.6%, respectively. Overall, the intradermally administered JYNNEOS vaccine appeared well tolerated.

S100 Calcium-Binding Protein A9, a Potential Novel Diagnostic Biomarker for Idiopathic Pulmonary Fibrosis.

BACKGROUND: Neutrophilic inflammation is a characteristic feature of idiopathic pulmonary fibrosis (IPF). S100 calcium-binding protein A9 (S100A9) is a neutrophil-derived protein involved in the development of neutrophil-related chronic inflammatory disorders. However, the role of S100A9 in IPF remains unclear. METHODS: We used enzyme-linked immunosorbent assays to measure S100A9 levels in bronchoalveolar lavage fluid (BALF) and serum obtained from healthy controls (HCs) and patients with IPF, non-specific interstitial pneumonia, hypersensitivity pneumonitis, and sarcoidosis. RESULTS: Compared with HCs, BALF S100A9 levels were significantly higher in IPF patients (P < 0.001), patients with hypersensitivity pneumonitis (P = 0.043), and patients with nonspecific interstitial pneumonia (P < 0.001). The S100A9 level in BALF of 0.093 ng/mL could distinguish IPF patients from HCs, with a specificity of 78.8% and a sensitivity of 81.6%. Similarly, the S100A9 level in BALF of 0.239 ng/mL had a specificity of 64.7% and a sensitivity of 66.7% for distinguishing IPF patients from patients with other interstitial lung diseases. Additionally, BALF S100A9 levels were significantly correlated with neutrophil counts (r = 0.356, P < 0.001) in BALF. IPF patients with S100A9 levels in BALF > 0.533 ng/mL had lower survival rates, compared with patients who had levels ≤ 0.553 ng/mL (n = 49; hazard ratio [HR], 3.62; P = 0.021). Combination analysis revealed that IPF patients with S100A9 levels in BALF> 0.553 ng/mL or neutrophil percentages > 49.1% (n = 43) had significantly lower survival rates than patients with S100A9 levels in BALF ≤ 0.553 ng/mL and neutrophil percentages ≤ 49.1% (n = 41) (HR, 3.91; P = 0.014). Additionally, patients with serum S100A9 levels > 0.077 ng/mL (n = 29) had significantly lower survival rates than patients with levels ≤ 0.077 ng/mL (n = 53, HR, 2.52; P = 0.013). S100A9 was expressed on neutrophils and macrophages in BALF from IPF patients as well as α-smooth muscle actin positive cells in the lung tissues. CONCLUSION: S100A9 is involved in the development and progression of IPF. Moreover, S100A9 levels in BALF and serum may be surrogate markers for IPF diagnosis and survival prediction, particularly when analyzed in combination with neutrophil percentages.

Genomic Analysis of Monkeypox Virus During the 2023 Epidemic in Korea.

We aimed to characterize the genomes of monkeypox virus isolates from the Far East, providing insights into viral transmission and evolution. Genomic analysis was conducted on 8 isolates obtained from patients with monkeypox virus disease in the Republic of Korea between May 2022 and early 2023. These isolates were classified into Clade IIb. Distinct lineages, including B.1.1, A.2.1, and B.1.3, were observed in 2022 and 2023 isolates, with only the B.1.3 lineage detected in six isolates of 2023. These genetic features were specific to Far East isolates (the Republic of Korea, Japan, and Taiwan), distinguishing them from the diverse lineages found in the Americas, Europe, Africa, and Oceania. In early 2023, the prevalence of the B.1.3 lineage of monkeypox virus identified in six patients with no overseas travel history is considered as an indicator of the potential initiation of local transmission in the Republic of Korea.

A Prospective Study of Preemptive Tenofovir Disoproxil Fumarate Therapy in HBsAg-Positive Patients With Diffuse Large B-Cell Lymphoma Receiving Rituximab Plus Cyclophosphamide, Doxorubicin, Vincristine, and Prednisone.

INTRODUCTION: This prospective study aimed to investigate the efficacy and safety of preemptive antiviral therapy with tenofovir disoproxil fumarate (TDF) for HBsAg-positive patients with newly diagnosed diffuse large B-cell lymphoma receiving rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) chemotherapy. METHODS: We enrolled 73 patients from 20 institutions. The primary end point was the absolute risk of hepatitis B virus (HBV)-related hepatitis during preemptive TDF therapy and for 24 weeks after withdrawal from TDF. Hepatitis was defined as a more than 3-fold increase in serum alanine aminotransferase from baseline or an alanine aminotransferase level of ≥100 U/L. HBV-related hepatitis was defined as hepatitis with an increase in serum HBV-DNA to >10 times that of the pre-exacerbation baseline or an absolute increase of ≥20,000 IU/mL compared with the baseline. RESULTS: No patient developed HBV reactivation or HBV-related hepatitis during preemptive antiviral therapy (until 48 weeks after completion of R-CHOP chemotherapy) with TDF. All adverse events were grade 1 or 2. HBV reactivation was reported in 17 (23.3%) patients. All HBV reactivation was developed at a median of 90 days after withdrawal from TDF (range, 37-214 days). Six (8.2%) patients developed HBV-related hepatitis at a median of 88 days after withdrawal from TDF (range, 37-183 days). DISCUSSION: Preemptive TDF therapy in HBsAg-positive patients with diffuse large B-cell lymphoma receiving R-CHOP chemotherapy was safe and effective for preventing HBV-related hepatitis. However, a long-term maintenance strategy of preemptive TDF therapy should be recommended because of the relatively high rate of HBV-related hepatitis after withdrawal from TDF ( ClinicalTrials.gov ID: NCT02354846).

Real-World Effectiveness of Nirmatrelvir-Ritonavir and Its Acceptability in High-Risk COVID-19 Patients.

BACKGROUND: Nirmatrelvir-ritonavir is highly effective in preventing severe coronavirus disease 2019 (COVID-19) in high-risk patients with mild-to-moderate severity. However, real-world performance data are limited, and the drug is not so acceptable to the COVID-19 patients at high risk who need it in Korea. METHODS: To evaluate the effectiveness of nirmatrelvir-ritonavir, we conducted a propensity score-matched retrospective cohort study on patients with mild-to-moderate COVID-19 at high risk for a severe disease who were hospitalized at four hospitals in South Korea from February 2022 to April 2022. A total of 236 patients in the treatment group (administered nirmatrelvir-ritonavir) and 236 in the matched control group (supportive care only) were analyzed for the primary outcome, i.e., the time to oxygen support-free survival. The secondary outcome was a composite result of disease progression. The reason for not prescribing nirmatrelvir-ritonavir to the indicated patients was also investigated. RESULTS: The treatment group showed significantly longer oxygen support-free survival than the matched control group (adjusted hazard ratio [aHR], 0.07; 95% confidence interval [CI], 0.01-0.31; P < 0.001). Multivariate Cox regression analysis showed that age (aHR, 1.03; 95% CI, 1.00-1.07), National Early Warning Score-2 at admission (aHR, 1.36; 95% CI, 1.08-1.71), nirmatrelvir-ritonavir treatment, female sex (aHR, 0.37; 95% CI, 0.15-0.88), and time from symptom onset to admission (aHR, 0.67; 95% CI, 0.48-0.95) were significantly associated with oxygen therapy. However, none of the factors were related to the composite outcome. In the unmatched control group, 19.9% of 376 patients had documented explanations for nirmatrelvir-ritonavir non-prescription, and 44.0% of these were due to contraindication criteria. In the treatment group, 10.9% of patients discontinued the medication primarily because of adverse events (71.4%), with gastrointestinal symptoms being the most common (50.0%). CONCLUSION: Nirmatrelvir-ritonavir treatment significantly reduced oxygen therapy requirements in high-risk patients with COVID-19 during the omicron variant surge in South Korea. Physicians are encouraged to consider the active use of nirmatrelvir-ritonavir and to be watchful for gastrointestinal symptoms during medication.

Short-Term Effectiveness of Oral Nirmatrelvir/Ritonavir Against the SARS-CoV-2 Omicron Variant and Culture-Positive Viral Shedding.

BACKGROUND: Information on the effectiveness of nirmatrelvir/ritonavir against the omicron is limited. The clinical response and viral kinetics to therapy in the real world need to be evaluated. METHODS: Mild to moderate coronavirus disease 2019 (COVID-19) patients with risk factors for severe illness were prospectively enrolled as a treatment group with nirmatrelvir/ritonavir therapy versus a control group with supportive care. Serial viral load and culture from the upper respiratory tract were evaluated for seven days, and clinical responses and adverse reactions were evaluated for 28 days. RESULTS: A total of 51 patients were analyzed including 40 in the treatment group and 11 in the control group. Faster symptom resolution during hospitalization (P = 0.048) was observed in the treatment group. Only minor adverse reactions were reported in 27.5% of patients. The viral load on Day 7 was lower in the treatment group (P = 0.002). The viral culture showed a positivity of 67.6% (25/37) vs. 100% (6/6) on Day 1, 0% (0/37) vs. 16.7 (1/6) on Day 5, and 0% (0/16) vs. 50.0% (2/4) on Day 7 in the treatment and control groups, respectively. CONCLUSIONS: Nirmatrelvir/ritonavir against the omicron was safe and resulted in negative viral culture conversion after Day 5 of treatment with better symptomatic resolution.

Tracking health system performance in times of crisis using routine health data: lessons learned from a multicountry consortium.

COVID-19 has prompted the use of readily available administrative data to track health system performance in times of crisis and to monitor disruptions in essential healthcare services. In this commentary we describe our experience working with these data and lessons learned across countries. Since April 2020, the Quality Evidence for Health System Transformation (QuEST) network has used administrative data and routine health information systems (RHIS) to assess health system performance during COVID-19 in Chile, Ethiopia, Ghana, Haiti, Lao People's Democratic Republic, Mexico, Nepal, South Africa, Republic of Korea and Thailand. We compiled a large set of indicators related to common health conditions for the purpose of multicountry comparisons. The study compiled 73 indicators. A total of 43% of the indicators compiled pertained to reproductive, maternal, newborn and child health (RMNCH). Only 12% of the indicators were related to hypertension, diabetes or cancer care. We also found few indicators related to mental health services and outcomes within these data systems. Moreover, 72% of the indicators compiled were related to volume of services delivered, 18% to health outcomes and only 10% to the quality of processes of care. While several datasets were complete or near-complete censuses of all health facilities in the country, others excluded some facility types or population groups. In some countries, RHIS did not capture services delivered through non-visit or nonconventional care during COVID-19, such as telemedicine. We propose the following recommendations to improve the analysis of administrative and RHIS data to track health system performance in times of crisis: ensure the scope of health conditions covered is aligned with the burden of disease, increase the number of indicators related to quality of care and health outcomes; incorporate data on nonconventional care such as telehealth; continue improving data quality and expand reporting from private sector facilities; move towards collecting patient-level data through electronic health records to facilitate quality-of-care assessment and equity analyses; implement more resilient and standardized health information technologies; reduce delays and loosen restrictions for researchers to access the data; complement routine data with patient-reported data; and employ mixed methods to better understand the underlying causes of service disruptions.

Therapeutic Hydrogel Patch to Treat Atopic Dermatitis by Regulating Oxidative Stress.

Atopic dermatitis (AD) is a chronic inflammatory disease associated with unbalanced immune responses in skin tissue. Although steroid drugs and antihistamines are generally used to treat AD, continuous administration causes multiple side effects. High oxidative stress derived from reactive oxygen species (ROS) has been implicated in the pathogenesis of AD. A high level of ROS promotes the release of pro-inflammatory cytokines and T-cell differentiation, resulting in the onset and deterioration of AD. Here, we report a therapeutic hydrogel patch suppressing the high oxidative stress generated in AD lesions. The hydrogel embedded with ROS-scavenging ceria nanoparticles leads to the decrease of both extracellular and intracellular ROS and exhibits cytoprotective effects in a highly oxidative condition. AD-induced mouse model studies show enhanced therapeutic outcomes, including a decrease in the epidermal thickness and levels of AD-associated immunological biomarkers. These findings indicate that a ROS-scavenging hydrogel could be a promising therapeutic hydrogel patch for treating and managing AD.

The Role of Erythrocyte Membrane Protein Band 4.1-like 3 in Idiopathic Pulmonary Fibrosis.

Novel genetic and epigenetic factors involved in the development and prognosis of idiopathic pulmonary fibrosis (IPF) have been identified. We previously observed that erythrocyte membrane protein band 4.1-like 3 (EPB41L3) increased in the lung fibroblasts of IPF patients. Thus, we investigated the role of EPB41L3 in IPF by comparing the EPB41L3 mRNA and protein expression of lung fibroblast between patients with IPF and controls. We also investigated the regulation of epithelial-mesenchymal transition (EMT) in an epithelial cell line (A549) and fibroblast-to-myofibroblast transition (FMT) in a fibroblast cell line (MRC5) by overexpressing and silencing EPB41L3. EPB41L3 mRNA and protein levels, as measured using RT-PCR, real-time PCR, and Western blot, were significantly higher in fibroblasts derived from 14 IPF patients than in those from 10 controls. The mRNA and protein expression of EPB41L3 was upregulated during transforming growth factor-ß-induced EMT and FMT. Overexpression of EPB41L3 in A549 cells using lenti-EPB41L3 transfection suppressed the mRNA and protein expression of N-cadherin and COL1A1. Treatment with EPB41L3 siRNA upregulated the mRNA and protein expression of N-cadherin. Overexpression of EPB41L3 in MRC5 cells using lenti-EPB41L3 transfection suppressed the mRNA and protein expression of fibronectin and α-SMA. Finally, treatment with EPB41L3 siRNA upregulated the mRNA and protein expression of FN1, COL1A1, and VIM. In conclusion, these data strongly support an inhibitory effect of EPB41L3 on the process of fibrosis and suggest the therapeutic potential of EPB41L3 as an anti-fibrotic mediator.

Calcium transients in intramuscular interstitial cells of Cajal of the murine gastric fundus and their regulation by neuroeffector transmission.

Enteric neurotransmission is critical for coordinating motility throughout the gastrointestinal (GI) tract. However, there is considerable controversy regarding the cells that are responsible for the transduction of these neural inputs. In the present study, utilization of a cell-specific calcium biosensor GCaMP6f, the spontaneous activity and neuroeffector responses of intramuscular ICC (ICC-IM) to motor neural inputs was examined. Simultaneous intracellular microelectrode recordings and high-speed video-imaging during nerve stimulation was used to reveal the temporal relationship between changes in intracellular Ca2+ and post-junctional electrical responses to neural stimulation. ICC-IM were highly active, generating intracellular Ca2+ -transients that occurred stochastically, from multiple independent sites in single ICC-IM. Ca2+ -transients were not entrained in single ICC-IM or between neighbouring ICC-IM. Activation of enteric motor neurons produced a dominant inhibitory response that abolished Ca2+ -transients in ICC-IM. This inhibitory response was often preceded by a summation of Ca2+ -transients that led to a global rise in Ca2+ . Individual ICC-IM responded to nerve stimulation by a global rise in Ca2+ followed by inhibition of Ca2+ -transients. The inhibition of Ca2+ -transients was blocked by the nitric oxide synthase antagonist l-NNA. The global rise in intracellular Ca2+ was inhibited by the muscarinic antagonist, atropine. Simultaneous intracellular microelectrode recordings with video-imaging revealed that the rise in Ca2+ was temporally associated with rapid excitatory junction potentials and the inhibition of Ca2+ -transients with inhibitory junction potentials. These data support the premise of serial innervation of ICC-IM in excitatory and inhibitory neuroeffector transmission in the proximal stomach. KEY POINTS: The cells responsible for mediating enteric neuroeffector transmission remain controversial. In the stomach intramuscular interstitial cells of Cajal (ICC-IM) were the first ICC reported to receive cholinergic and nitrergic neural inputs. Utilization of a cell specific calcium biosensor, GCaMP6f, the activity, and neuroeffector responses of ICC-IM were examined. ICC-IM were highly active, generating stochastic intracellular Ca2+ -transients. Stimulation of enteric motor nerves abolished Ca2+ -transients in ICC-IM. This inhibitory response was preceded by a global rise in intracellular Ca2+ . Individual ICC-IM responded to nerve stimulation with a rise in Ca2+ followed by inhibition of Ca2+ -transients. Inhibition of Ca2+ -transients was blocked by the nitric oxide synthase antagonist l-NNA. The global rise in Ca2+ was inhibited by the muscarinic antagonist atropine. Simultaneous intracellular recordings with video imaging revealed that the global rise in intracellular Ca2+ and inhibition of Ca2+ -transients was temporally associated with rapid excitatory junction potentials followed by more sustained inhibitory junction potentials. The data presented support the premise of serial innervation of ICC-IM in excitatory and inhibitory neuroeffector transmission in the proximal stomach.

Association of ATP8B3 gene polymorphisms with aspirin-exacerbated respiratory disease in asthmatics.

BACKGROUND: Aspirin-exacerbated respiratory disease (AERD), an asthma phenotype, often presents with severe manifestations and it remains widely underdiagnosed because of insufficient awareness of the relationship between the ingestion of nonsteroidal anti-inflammatory drugs, including acetylsalicylic acid (ASA), and asthma exacerbation. Our previous genome-wide association study demonstrated an association between a single nucleotide polymorphism (SNP) of the ATP8B3 gene and the risk of AERD. This study examined AERD-related SNPs of the ATP8B3 gene in a large population. METHODS: Twenty-five SNPs of ATP8B3 were genotyped with the GoldenGate assay using VeraCode microbeads in 141 asthmatics with AERD and 995 Aspirin-tolerant asthma (ATA). The genotype distribution was analyzed using logistic regression models. The declines in forced expiratory volume in 1 second (FEV1)following an ASA challenge were compared among the genotypes and haplotypes using a type III generalized linear model. RESULTS: The minor allele frequencies (MAFs) of rs10421558 A>G in the 5'UTR and rs10403288 G>A in the intron were significantly lower in the AERD than the ATA [34.0% vs. 43.8%, OR = 0.66 (0.62-0.92), Pcorr = 0.03 and 28.4% vs. 35.4%, OR = 0.62 (0.59-0.89), Pcorr = 0.016, respectively]. BL1ht5 was significantly higher in the AERD [7.6% vs. 1.6%, OR = 12.23 (0.2-0.51), P = 4.7 × 10 -4 , Pcorr = 0.001]. Among them, rs10421558 A>G and BL1ht5 were associated with the percent decline in FEV1 on the oral ASA challenge test. CONCLUSION: The minor allele of rs10421558 A>G in the 5'UTR may protect against the development of AERD via the increased production of ATP8B3.

Determination of volatile organic compounds (VOCs) levels from various smoking cessation aids by using gas chromatography-mass spectrometry methodology.

An analytical method was validated and developed to determine the levels of volatile organic compounds (VOCs) including 1,3-butadiene, isoprene, acrylonitrile, benzene, toluene, and styrene from smoking cessation aids using by gas chromatography-mass spectrometry (GC-MS). Seventeen non-ignitable cigarette type of smoking cessation aids, liquid-phase of smoking cessation aids, gas-phase of smoking cessation aids, and ignitable cigarette type of smoking cessation aids were analyzed for levels of six VOCs. The proposed method for six VOCs was validated in satisfactory linearity (R2 > 0.99), recovery (80.38-119.14%). limit of detection (LOD) (0.05-0.19 µg/ml), limit of quantification (LOQ) (0.07-0.18 µg/ml), accuracy (80.47-117.28%), and precision (0.15-7.22%). The mean concentrations of six VOCs were generated in 1,3-butadiene (6.18 µg/cigarette), isoprene (0.34 µg/cigarette), acrylonitrile (0.003 µg/cigarette), benzene (ND = not detected, the lower limit of detection), toluene (0.27 µg/cigarette), styrene (0.13 µg/cigarette). Results showed low levels of VOCs from smoking cessation aid except from liquid-phase of smoking cessation aids. These results are necessary to investigate unintentional hazardous substances generated from smoking cessation aids, and develop accurate analytical method in order to obtain scientific basis for safety management.