Facility wastewater monitoring as an effective tool for pandemic infection control: An experience in COVID-19 pandemic with long-term monitoring.

INTRODUCTION: Since the first report of a novel coronavirus infection caused by SARS-CoV-2 in late 2019, the infection has spread rapidly and had a significant impact on our lives. In the early stages of the COVID-19 pandemic, there was no adequate testing system in place, despite an urgent need for infection control measures in student dormitories. METHODS: We have been monitoring SARS-CoV-2 in wastewater as part of our infection control efforts in the university facilities since fall 2020. In the four dormitories, absorbent cotton was placed in the drains that the facility wastewater passed through, and samples were collected twice a week and processed by RT-PCR for SARS-CoV-2. The dormitory residents were informed of the monitoring results the next morning. RESULTS: The positivity of residents in the dormitories was highly consistent with the positivity of wastewater. Wastewater was positive in 89 % of cases before any residents were tested and found positive. Facility wastewater monitoring showed sensitivities of 80.4 % and specificities of 87.6 %. No traceable resident-to-resident transmission of infection within the facility was confirmed during the study period. CONCLUSION: Sampling a single wastewater outlet in a building for SARS-CoV-2 PCR can effectively indicate the presence or absence of COVID-19 cases and be very useful for infection control of a facility. This simple and effective monitoring is applicable to future outbreaks of both emerging and re-emerging infectious diseases.

Interpretations of SARS-CoV-2 IgM and IgG antibody titers in the seroepidemiological study of asymptomatic healthy volunteers.

INTRODUCTION: The usefulness of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody tests in asymptomatic individuals has not been well validated, although they have satisfied sensitivity and specificity in symptomatic patients. In this study, we investigated the significance of IgM and IgG antibody titers against SARS-CoV-2 in the serum of asymptomatic healthy subjects. METHODS: From June 2020, we recruited 10,039 participants to the project named the University of Tokyo COVID-19 Antibody Titer Survey (UT-CATS), and measured iFlash-SARS-CoV-2 IgM and IgG (YHLO IgM and IgG) titers in the collected serum. For the samples with increased IgM or IgG titers, we performed additional measurements using Elecsys Anti-SARS-CoV-2 Ig (Roche total Ig) and Architect SARS-CoV-2 IgG (Abbott IgG) and investigated the reactivity to N, S1, and receptor binding domain (RBD) proteins. RESULTS: After setting the cutoff value at 5 AU/mL, 61 (0.61%) were positive for YHLO IgM and 104 (1.04%) for YHLO IgG. Few samples with elevated YHLO IgM showed reactivity to S1 or RBD proteins, and IgG titers did not increase during the follow-up in any samples. The samples with elevated YHLO IgG consisted of two groups: one reacted to S1 or RBD proteins and the other did not, which was reflected in the results of Roche total Ig. CONCLUSIONS: In SARS-CoV-2 seroepidemiological studies of asymptomatic participants, sufficient attention should be given to the interpretation of the results of YHLO IgM and IgG, and the combined use of YHLO IgG and Roche total Ig might be more reliable.

Epidemiological study using IgM and IgG antibody titers against SARS-CoV-2 in The University of Tokyo, Japan (UT-CATS).

INTRODUCTION: The worldwide pandemic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has continued to date. Given that some of the patients with coronavirus disease 2019 (COVID-19) are asymptomatic, antibody tests are useful to determine whether there is a previous infection with SARS-CoV-2. In this study, we measured IgM and IgG antibody titers against SARS-CoV-2 in the serum of asymptomatic healthy subjects in The University of Tokyo, Japan. METHODS: From June 2020, we recruited participants, who were students, staff, and faculty members of The University of Tokyo in the project named The University of Tokyo COVID-19 Antibody Titer Survey (UT-CATS). Following blood sample collection, participants were required to answer an online questionnaire about their social and health information. We measured IgG and IgM titers against SARS-CoV-2 using iFlash-SARS-CoV-2 IgM and IgG detection kit which applies a chemiluminescent immunoassay (CLIA) for the qualitative detection. RESULTS: There were 6609 volunteers in this study. After setting the cutoff value at 10 AU/mL, 32 (0.48%) were positive for IgG and 16 (0.24%) for IgM. Of six participants with a history of COVID-19, five were positive for IgG, whereas all were negative for IgM. The median titer of IgG was 0.40 AU/mL and 0.39 AU/mL for IgM. Both IgG and IgM titers were affected by gender, age, smoking status, and comorbidities. CONCLUSIONS: Positive rates of IgG and IgM titers were relatively low in our university. Serum levels of these antibodies were affected by several factors, which might affect the clinical course of COVID-19.

Genome-wide integration of microRNA and transcriptomic profiles of differentiating human alveolar epithelial cells.

The alveolar epithelium is comprised of two cell types, alveolar epithelial type 1 (AT1) and type 2 (AT2) cells, the latter being capable of self-renewal and transdifferentiation into AT1 cells for normal maintenance and restoration of epithelial integrity following injury. MicroRNAs (miRNAs) are critical regulators of several biological processes, including cell differentiation; however, their role in establishment/maintenance of cellular identity in adult alveolar epithelium is not well understood. To investigate this question, we performed genome-wide analysis of sequential changes in miRNA and gene expression profiles using a well-established model in which human AT2 (hAT2) cells transdifferentiate into AT1-like cells over time in culture that recapitulates many aspects of transdifferentiation in vivo. We defined three phases of miRNA expression during the transdifferentiation process as "early," "late," and "consistently" changed, which were further subclassified as up- or downregulated. miRNAs with altered expression at all time points during transdifferentiation were the largest subgroup, suggesting the need for consistent regulation of signaling pathways to mediate this process. Target prediction analysis and integration with previously published gene expression data identified glucocorticoid signaling as the top pathway regulated by miRNAs. Serum/glucocorticoid-regulated kinase 1 (SGK1) emerged as a central regulatory factor, whose downregulation correlated temporally with gain of hsa-miR-424 and hsa-miR-503 expression. Functional validation demonstrated specific targeting of these miRNAs to the 3'-untranslated region of SGK1. These data demonstrate the time-related contribution of miRNAs to the alveolar transdifferentiation process and suggest that inhibition of glucocorticoid signaling is necessary to achieve the AT1-like cell phenotype.

Pleural thickening on screening chest X-rays: a single institutional study.

Although pleural thickening is a common finding on routine chest X-rays, its radiological and clinical features remain poorly characterized. Our investigation of 28,727 chest X-rays obtained from annual health examinations confirmed that pleural thickening was the most common abnormal radiological finding. In most cases (92.2%), pleural thickening involved the apex of the lung, particularly on the right side; thus, it was defined as a pulmonary apical cap. Pleural thickening was more common in males than in females and in current smokers or ex-smokers than in never smokers. The prevalence increased with age, ranging from 1.8% in teenagers to 9.8% in adults aged 60 years and older. Moreover, pleural thickening was clearly associated with greater height and lower body weight and body mass index, suggesting that a tall, thin body shape may predispose to pleural thickening. These observations allowed us to speculate about the causative mechanisms of pleural thickening that are attributable to disproportionate perfusion, ventilation, or mechanical forces in the lungs.

Cross-Species Transcriptome Profiling Identifies New Alveolar Epithelial Type I Cell-Specific Genes.

Diseases involving the distal lung alveolar epithelium include chronic obstructive pulmonary disease, idiopathic pulmonary fibrosis, and lung adenocarcinoma. Accurate labeling of specific cell types is critical for determining the contribution of each to the pathogenesis of these diseases. The distal lung alveolar epithelium is composed of two cell types, alveolar epithelial type 1 (AT1) and type 2 (AT2) cells. Although cell type-specific markers, most prominently surfactant protein C, have allowed detailed lineage tracing studies of AT2 cell differentiation and the cells' roles in disease, studies of AT1 cells have been hampered by a lack of genes with expression unique to AT1 cells. In this study, we performed genome-wide expression profiling of multiple rat organs together with purified rat AT2, AT1, and in vitro differentiated AT1-like cells, resulting in the identification of 54 candidate AT1 cell markers. Cross-referencing with genes up-regulated in human in vitro differentiated AT1-like cells narrowed the potential list to 18 candidate genes. Testing the top four candidate genes at RNA and protein levels revealed GRAM domain 2 (GRAMD2), a protein of unknown function, as highly specific to AT1 cells. RNA sequencing (RNAseq) confirmed that GRAMD2 is transcriptionally silent in human AT2 cells. Immunofluorescence verified that GRAMD2 expression is restricted to the plasma membrane of AT1 cells and is not expressed in bronchial epithelial cells, whereas reverse transcription-polymerase chain reaction confirmed that it is not expressed in endothelial cells. Using GRAMD2 as a new AT1 cell-specific gene will enhance AT1 cell isolation, the investigation of alveolar epithelial cell differentiation potential, and the contribution of AT1 cells to distal lung diseases.

p300/ß-Catenin Interactions Regulate Adult Progenitor Cell Differentiation Downstream of WNT5a/Protein Kinase C (PKC).

Maintenance of stem/progenitor cell-progeny relationships is required for tissue homeostasis during normal turnover and repair. Wnt signaling is implicated in both maintenance and differentiation of adult stem/progenitor cells, yet how this pathway serves these dichotomous roles remains enigmatic. We previously proposed a model suggesting that specific interaction of ß-catenin with either of the homologous Kat3 co-activators, p300 or CREB-binding protein, differentially regulates maintenance versus differentiation of embryonic stem cells. Limited knowledge of endogenous mechanisms driving differential ß-catenin/co-activator interactions and their role in adult somatic stem/progenitor cell maintenance versus differentiation led us to explore this process in defined models of adult progenitor cell differentiation. We focused primarily on alveolar epithelial type II (AT2) cells, progenitors of distal lung epithelium, and identified a novel axis whereby WNT5a/protein kinase C (PKC) signaling regulates specific ß-catenin/co-activator interactions to promote adult progenitor cell differentiation. p300/ß-catenin but not CBP/ß-catenin interaction increases as AT2 cells differentiate to a type I (AT1) cell-like phenotype. Additionally, p300 transcriptionally activates AT1 cell-specific gene Aqp-5. IQ-1, a specific inhibitor of p300/ß-catenin interaction, prevents differentiation of not only primary AT2 cells, but also tracheal epithelial cells, and C2C12 myoblasts. p300 phosphorylation at Ser-89 enhances p300/ß-catenin interaction, concurrent with alveolar epithelial cell differentiation. WNT5a, a traditionally non-canonical WNT ligand regulates Ser-89 phosphorylation and p300/ß-catenin interactions in a PKC-dependent manner, likely involving PKCζ. These studies identify a novel intersection of canonical and non-canonical Wnt signaling in adult progenitor cell differentiation that has important implications for targeting ß-catenin to modulate adult progenitor cell behavior in disease.

Region-specific role for Pten in maintenance of epithelial phenotype and integrity.

Previous studies have demonstrated resistance to naphthalene-induced injury in proximal airways of mice with lung epithelial-specific deletion of the tumor-suppressor gene Pten, attributed to increased proliferation of airway progenitors. We tested effects of Pten loss following bleomycin injury, a model typically used to study distal lung epithelial injury, in conditional PtenSFTPC-cre knockout mice. Pten-deficient airway epithelium exhibited marked hyperplasia, particularly in small bronchioles and at bronchoalveolar duct junctions, with reduced E-cadherin and ß-catenin expression between cells toward the luminal aspect of the hyperplastic epithelium. Bronchiolar epithelial and alveolar epithelial type II (AT2) cells in PtenSFTPC-cre mice showed decreased expression of epithelial markers and increased expression of mesenchymal markers, suggesting at least partial epithelial-mesenchymal transition at baseline. Surprisingly, and in contrast to previous studies, mutant mice were exquisitely sensitive to bleomycin, manifesting rapid weight loss, respiratory distress, increased early mortality (by day 5), and reduced dynamic lung compliance. This was accompanied by sloughing of the hyperplastic airway epithelium with occlusion of small bronchioles by cellular debris, without evidence of increased parenchymal lung injury. Increased airway epithelial cell apoptosis due to loss of antioxidant defenses, reflected by decreased expression of superoxide dismutase 3, in combination with deficient intercellular adhesion, likely predisposed to airway sloughing in knockout mice. These findings demonstrate an important role for Pten in maintenance of airway epithelial phenotype integrity and indicate that responses to Pten deletion in respiratory epithelium following acute lung injury are highly context-dependent and region-specific.

The chimeric transcript RUNX1-GLRX5: a biomarker for good postoperative prognosis in Stage IA non-small-cell lung cancer.

Stage IA non-small-cell lung cancer cases have been recognized as having a low risk of relapse; however, occasionally, relapse may occur. To predict clinical outcome in Stage IA non-small-cell lung cancer patients, we searched for chimeric transcripts that can be used as biomarkers and identified a novel chimeric transcript, RUNX1-GLRX5, comprising RUNX1, a transcription factor, and GLRX5. This chimera was detected in approximately half of the investigated Stage IA non-small-cell lung cancer patients (44/104 cases, 42.3%). Although there was no significant difference in the overall survival rate between RUNX1-GLRX5-positive and -negative cases (P = 0.088), a significantly lower relapse rate was observed in the RUNX1-GLRX5-positive cases (P = 0.039), indicating that this chimera can be used as a biomarker for good prognosis in Stage IA patients. Detection of the RUNX1-GLRX5 chimeric transcript may therefore be useful for the determination of a postoperative treatment plan for Stage IA non-small-cell lung cancer patients.

Oncogenic TPM3-ALK activation requires dimerization through the coiled-coil structure of TPM3.

Inflammatory myofibroblastic tumor (IMT) is a mesenchymal tumor that can arise from anywhere in the body. Anaplastic lymphoma kinase (ALK) gene rearrangements, most often resulting in the tropomyosin 3 (TPM3)-ALK fusion gene, are the main causes of IMT. However, the mechanism of malignant transformation in IMT has yet to be elucidated. The purpose of this study was to clarify the role of the TPM3 region in the transformation of IMT via TPM3-ALK. Lentivirus vectors containing a TPM3-ALK fusion gene lacking various lengths of TPM3 were constructed and expressed in HEK293T and NIH3T3 cell lines. Focus formation assay revealed loss of contact inhibition in NIH3T3 cells transfected with full-length TPM3-ALK, but not with ALK alone. Blue-native polyacrylamide gel electrophoresis (BN-PAGE) revealed that TPM3-ALK dimerization increased in proportion to the length of TPM3. Western blot showed phosphorylation of ALK, ERK1/2, and STAT3 in HEK293T cells transfected with TPM3-ALK. Thus, the coiled-coil structure of TPM3 contributes to the transforming ability of the TPM3-ALK fusion protein, and longer TPM3 region leads to higher dimer formation.

Clinical features of 280 hospitalized patients with lymphangioleiomyomatosis in Japan.

BACKGROUND AND OBJECTIVE: Lymphangioleiomyomatosis (LAM) is rare, but potentially life threatening owing to respiratory failure. However, knowledge is limited about the condition of hospitalized LAM patients. The objectives of this study were to investigate patient characteristics, comorbidities and causes of death among hospitalized LAM patients in Japan. METHODS: Using a national inpatient database in Japan, information on 280 LAM patients hospitalized between July 2010 and March 2013 was retrospectively collected. We divided the 280 patients into three groups according to their status regarding lung transplantation. RESULTS: For the study period, we identified 32 patients who had undergone lung transplantation ('after-transplantation' group), 12 patients admitted for lung transplantation ('for-transplantation') and 236 patients who had not undergone transplantation ('no-transplantation'). Although the clinical features of LAM patients in the 'no-transplantation' group were similar to previously reported findings, patients hospitalized in connection with transplantation showed the following: the activities of daily living score using the Barthel Index in the 'after-transplantation' group (89.4) was significantly higher than in the 'for-transplantation' group (64.6); the mortality rates in the after-transplantation group (3.1%) were significantly lower than in the for-transplantation group (25%). The most frequent comorbidity was pneumothorax, followed by respiratory failure and angiomyolipoma, although there was no significant difference in the prevalence among the three groups. CONCLUSIONS: We determined the clinical features, comorbidities and fatalities in hospitalized LAM patients. Patients with LAM after transplantation had higher activities of daily living scores than those before transplantation, which suggests that lung transplantation may improve activities of daily living.

Factors affecting mortality following emergency admission for chronic obstructive pulmonary disease.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a major cause of mortality worldwide. Patients with COPD frequently have systemic comorbidities that often require unscheduled hospitalization for exacerbation and deterioration of physical conditions, and can have a poor prognosis. We verified factors affecting patients' short-term mortality, using a national inpatient database in Japan. METHODS: We retrospectively collected data for COPD patients (age: >40 years) with emergency admission between July 2010 and March 2013, using the Diagnosis Procedure Combination database. We performed multivariate logistic analyses fitted with a generalized estimating equation to assess factors associated with all-cause in-hospital mortality. RESULTS: A total of 177,207 patients (mean age: 77.5 years; males: 72.9%) were identified. All-cause in-hospital death occurred in 23,614 patients (13.7%). Higher mortality was associated with older age, male sex, lower body mass index, more severe dyspnea, lower level of consciousness, and worse activities of daily life. Higher mortality was also associated with comorbid conditions, including bacterial pneumonia, aspiration pneumonia, interstitial pneumonitis, pulmonary embolism, respiratory failure, lung cancer, heart failure, cerebral infarction, liver cirrhosis, and chronic renal failure. CONCLUSIONS: Our study demonstrated that all-cause in-hospital mortality in patients with COPD who required emergency hospitalization was associated with deteriorated general conditions and comorbidities at admission. Physicians should take into account these prognostic factors to choose better treatment options for COPD patients.

Detection of novel paraja ring finger 2-fer tyrosine kinase mRNA chimeras is associated with poor postoperative prognosis in non-small cell lung cancer.

Previously, we reported that the overexpression of fer tyrosine kinase (FER), a non-receptor tyrosine kinase, is correlated with poor postoperative prognosis and cancer-cell survival in non-small cell lung cancer (NSCLC). In the present study, we further analyzed FER-overexpressed NSCLC cases and identified various patterns of chimeric mRNAs, composed of paraja ring finger 2 (PJA2) and FER. We detected no genomic rearrangements between PJA2 and FER and attributed these chimeric mRNAs to alterations at the transcriptome level: i.e., trans-splicing. Several chimeric patterns were detected concurrently in each patient, and the pattern sets varied among patients, although the pattern in which PJA2 exon 1 was fused to FER exon 3 (designated as Pe1-Fe3 mRNA) was detected constantly. Therefore, in a wide screening for PJA2-FER mRNAs in NSCLC, we focused on this chimeric pattern as a representative chimera. In analyses of 167 NSCLC samples, Pe1-Fe3 mRNA was identified in about 10% of the patients, and the presence of chimeric mRNA was significantly correlated with a high expression level of parental FER mRNA. Furthermore, we found that the detection of Pe1-Fe3 mRNA was correlated with poor postoperative survival periods in NSCLC, consistent with a previous finding in which FER overexpression was correlated with poor postoperative prognosis in NSCLC. This report is the first to suggest a correlation between chimeric mRNA and the expression level of parental mRNA. Furthermore, our findings may be clinically beneficial, suggesting that PJA2-FER mRNAs might serve as a novel prognostic biomarker in NSCLC.

Waning cellular immune responses and predictive factors in maintaining cellular immunity against SARS-CoV-2 six months after BNT162b2 mRNA vaccination.

Several clinical trials have shown that the humoral response produced by anti-spike antibodies elicited by coronavirus disease 2019 (COVID-19) vaccines gradually declines. The kinetics, durability and influence of epidemiological and clinical factors on cellular immunity have not been fully elucidated. We analyzed cellular immune responses elicited by BNT162b2 mRNA vaccines in 321 health care workers using whole blood interferon-gamma (IFN-γ) release assays. IFN-γ, induced by CD4 + and CD8 + T cells stimulated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike epitopes (Ag2), levels were highest at 3 weeks after the second vaccination (6 W) and decreased by 37.4% at 3 months (4 M) and 60.0% at 6 months (7 M), the decline of which seemed slower than that of anti-spike antibody levels. Multiple regression analysis revealed that the levels of IFN-γ induced by Ag2 at 7 M were significantly correlated with age, dyslipidemia, focal adverse reactions to full vaccination, lymphocyte and monocyte counts in whole blood, Ag2 levels before the second vaccination, and Ag2 levels at 6 W. We clarified the dynamics and predictive factors for the long-lasting effects of cellular immune responses. The results emphasize the need for a booster vaccine from the perspective of SARS-CoV-2 vaccine-elicited cellular immunity.

Genome structure-based screening identified epigenetically silenced microRNA associated with invasiveness in non-small-cell lung cancer.

MicroRNA (miRNA) expression is frequently altered in human cancers. To search for epigenetically silenced miRNAs in non-small-cell lung cancer (NSCLC), we mapped human miRNAs on autosomal chromosomes and selected 55 miRNAs in silico. We treated six NSCLC cell lines with the DNA methylation inhibitor 5-aza-2'-deoxycytidine (5-aza-CdR) and determined the expressions of the 55 miRNAs. Fourteen miRNAs were decreased in the cancer cell lines and were induced after 5-aza-CdR treatment. After a detailed DNA methylation analysis, we found that mir-34b and mir-126 were silenced by DNA methylation. Mir-34b was silenced by the DNA methylation of its own promoter, whereas mir-126 was silenced by the DNA methylation of its host gene, EGFL7. A chromatin immunoprecipitation assay revealed H3K9me2 and H3K9me3 in mir-34b and EGFL7, and H3K27me3 in EGFL7. The overexpression of mir-34b and mir-126 decreased the expression of c-Met and Crk, respectively. The 5-aza-CdR treatment of lung cancer cell line resulted in increased mir-34b expression and decreased c-Met protein. We next analyzed the DNA methylation status of these miRNAs using 99 primary NSCLCs. Mir-34b and mir-126 were methylated in 41 and 7% of all the cases, respectively. The DNA methylation of mir-34b was not associated with c-Met expression determined by immunohistochemistry, but both mir-34b methylation (p = 0.007) and c-Met expression (p = 0.005) were significantly associated with lymphatic invasion in a multivariate analysis. The DNA methylation of mir-34b can be used as a biomarker for an invasive phenotype of lung cancer.

Polymerase reaction without primers throughout for the reconstruction of full-length cDNA from products of rapid amplification of cDNA ends (RACE).

Rapid amplification of cDNA ends (RACE) has widely been used to determine both ends of the cDNA from its partial sequence. Conventionally, 5'- and 3'-RACE products were ligated at a restriction site in the overlap region to reconstruct the full-length cDNA; however, reconstruction is difficult if no appropriate restriction enzymes are available. Here, we report a novel method to reconstruct full-length cDNA with DNA polymerase. Instead of usual PCR, chain reactions were avoided and the elongation time was shortened, which enables non-specific products or undesired point mutations to be minimized. We successfully reconstructed and TA-cloned a full-length cDNA of echinoderm microtubule-associated protein-like 4 (EML4)-anaplastic lymphoma kinase (ALK) fusion gene variant 2 from RACE products obtained from a surgically resected lung adenocarcinoma sample. We also evaluated some parameters to provide recommendations for this new method.

Treatment of PCR products with exonuclease I and heat-labile alkaline phosphatase improves the visibility of combined bisulfite restriction analysis.

DNA methylation plays a vital role in the regulation of gene expression. Abnormal promoter hypermethylation is an important mechanism of inactivating tumor suppressor genes in human cancers. Combined bisulfite restriction analysis (COBRA) is a widely used method for identifying the DNA methylation of specific CpG sites. Here, we report that exonuclease I and heat-labile alkaline phosphatase can be used for PCR purification for COBRA, improving the visibility of gel electrophoresis after restriction digestion. This improvement is observed when restriction digestion is performed at a high temperature, such as 60 degrees C or 65 degrees C, with BstUI and TaqI, respectively. This simple method can be applied instead of DNA purification using spin columns or phenol/chloroform extraction. It can also be applied to other situations when PCR products are digested by thermophile-derived restriction enzymes, such as PCR restriction fragment length polymorphism (RFLP) analysis.

[Case of sarcoidosis with squamous cell carcinoma which originated from solitary bronchial papilloma].

A 60-year-old man was given a clinical diagnosis of sarcoidosis, with enlarged mediastinal and hilar lymphadenopathy by chest CT, high levels of angiotensin-converting enzyme, and gallium scintigraphy findings. After 2 years follow-up, chest CT showed that only the right superior lobe bronchial lymph node had enlarged, occluding the right B1 bronchus, but other enlarged lymph nodes had not changed in size. We performed bronchoscopy to evaluate the occlusion of the right B1 bronchus, and recognized a polypoid lesion. Transbronchial tumor biopsy specimens revealed squamous cell lung carcinoma. A right upper lobectomy and drainage of the hilar and mediastinal lymph regions were performed. Histopathological examination revealed the coexistence of squamous cell carcinoma with many non-caseating epithelioid cell granulomas in all hilar and mediastinal drainage lymph nodes, but no metastasis. Non-caseating epithelioid cell granulomas were also seen in the lung interstitium. Histopathological examination suggested that the squamous cell carcinoma originated from a solitary bronchial papilloma. A diagnosis of lung cancer complicated with sarcoidosis was difficult by clinical imaging alone, including FDG-PET/CT. This suggests the importance of bronchoscopic examination, if a clinical course of the disease appears to be different from the usual course. This was a rare case of squamous cell carcinoma which originated from a solitary bronchial papilloma.

Integrated Single-Cell RNA-Sequencing Analysis of Aquaporin 5-Expressing Mouse Lung Epithelial Cells Identifies GPRC5A as a Novel Validated Type I Cell Surface Marker.

Molecular and functional characterization of alveolar epithelial type I (AT1) cells has been challenging due to difficulty in isolating sufficient numbers of viable cells. Here we performed single-cell RNA-sequencing (scRNA-seq) of tdTomato+ cells from lungs of AT1 cell-specific Aqp5-Cre-IRES-DsRed (ACID);R26tdTomato reporter mice. Following enzymatic digestion, CD31-CD45-E-cadherin+tdTomato+ cells were subjected to fluorescence-activated cell sorting (FACS) followed by scRNA-seq. Cell identity was confirmed by immunofluorescence using cell type-specific antibodies. After quality control, 92 cells were analyzed. Most cells expressed 'conventional' AT1 cell markers (Aqp5, Pdpn, Hopx, Ager), with heterogeneous expression within this population. The remaining cells expressed AT2, club, basal or ciliated cell markers. Integration with public datasets identified three robust AT1 cell- and lung-enriched genes, Ager, Rtkn2 and Gprc5a, that were conserved across species. GPRC5A co-localized with HOPX and was not expressed in AT2 or airway cells in mouse, rat and human lung. GPRC5A co-localized with AQP5 but not pro-SPC or CC10 in mouse lung epithelial cell cytospins. We enriched mouse AT1 cells to perform molecular phenotyping using scRNA-seq. Further characterization of putative AT1 cell-enriched genes revealed GPRC5A as a conserved AT1 cell surface marker that may be useful for AT1 cell isolation.

Isolation of Rat and Mouse Alveolar Type II Epithelial Cells.

The gas exchange surface of the lungs is lined by an epithelium consisting of alveolar type (AT) I and ATII cells. ATII cells function to produce surfactant, play a role in host defense and fluid and ion transport, and serve as progenitors. ATI cells are important for gas exchange and fluid and ion transport. Our understanding of the biology of these cells depends on the investigation of isolated cells. Here, we present methods for the isolation of mouse and rat ATII cells.