Airway stem cell reconstitution by the transplantation of primary or pluripotent stem cell-derived basal cells.

Life-long reconstitution of a tissue's resident stem cell compartment with engrafted cells has the potential to durably replenish organ function. Here, we demonstrate the engraftment of the airway epithelial stem cell compartment via intra-airway transplantation of mouse or human primary and pluripotent stem cell (PSC)-derived airway basal cells (BCs). Murine primary or PSC-derived BCs transplanted into polidocanol-injured syngeneic recipients give rise for at least two years to progeny that stably display the morphologic, molecular, and functional phenotypes of airway epithelia. The engrafted basal-like cells retain extensive self-renewal potential, evident by the capacity to reconstitute the tracheal epithelium through seven generations of secondary transplantation. Using the same approach, human primary or PSC-derived BCs transplanted into NOD scid gamma (NSG) recipient mice similarly display multilineage airway epithelial differentiation in vivo. Our results may provide a step toward potential future syngeneic cell-based therapy for patients with diseases resulting from airway epithelial cell damage or dysfunction.

Risk factors for the development of second primary esophageal squamous-cell carcinoma after endoscopic resection for esophageal squamous-cell carcinoma according to genetic polymorphisms related to alcohol and nicotine metabolism.

BACKGROUND: Multiple development of esophageal squamous-cell carcinoma is explained by field cancerization and is associated with alcohol consumption and smoking. We investigated the association between the development of second primary esophageal squamous-cell carcinoma after endoscopic resection for esophageal squamous-cell carcinoma and genetic polymorphisms related to alcohol and nicotine metabolism. METHODS: The study group comprised 56 patients with esophageal squamous-cell carcinoma after endoscopic resection. The main variables were the following: (i) cumulative incidence and total number of second primary esophageal squamous-cell carcinoma according to genetic polymorphisms in alcohol dehydrogenase 1B, aldehyde dehydrogenase 2 and cytochrome P450 2A6; and (ii) risk factors of second primary esophageal squamous-cell carcinoma identified using a multivariate Cox proportional-hazards model. The frequencies of alcohol dehydrogenase 1B, aldehyde dehydrogenase 2 and cytochrome P450 2A6 genetic polymorphisms in the buccal mucosa were analyzed. RESULTS: The median follow-up was 92.8 months (range: 2.7-134.2). Slow-metabolizing alcohol dehydrogenase 1B was associated with a higher 7-year cumulative incidence of second primary esophageal squamous-cell carcinoma (fast-metabolizing alcohol dehydrogenase 1B vs slow-metabolizing alcohol dehydrogenase 1B: 20.5% vs 71.4%, P = 0.006). Slow-metabolizing alcohol dehydrogenase 1B (relative risk [95% confidence interval]: 3.17 [1.49-6.73]), inactive aldehyde dehydrogenase 2 (2.17 [1.01-4.63]) and poorly-metabolizing cytochrome P450 2A6 (4.63 [1.74-12.33]) had a significantly higher total number of second primary esophageal squamous-cell carcinoma per 100 person-years. In the multivariate Cox proportional-hazards model, slow-metabolizing alcohol dehydrogenase 1B was a significant risk factor of the development of second primary esophageal squamous-cell carcinoma (hazard ratio 9.92, 95% confidence interval: 2.35-41.98, P = 0.0018). CONCLUSIONS: Slow-metabolizing alcohol dehydrogenase 1B may be a significant risk factor for the development of second primary esophageal squamous-cell carcinoma. In addition, inactive aldehyde dehydrogenase 2 and poorly-metabolizing cytochrome P450 2A6 may be important factors.

Metachronous primary gastric cancer after endoscopic resection in patients with esophageal squamous cell carcinoma.

BACKGROUND: This study aimed to evaluate the risk factors for developing metachronous primary Gastric Cancer (GC) after Endoscopic Resection (ER) for esophageal Squamous Cell Carcinoma (SCC). METHODS: We studied 283 patients with esophageal SCC who underwent ER. The study outcomes were as follows: (1) incidence of metachronous primary GC after ER; and (2) predictors for the development of metachronous primary GC after ER by the Cox proportional hazards model. RESULTS: The median follow-up was 43.1 months (1.81-79.1), and the 3-year cumulative incidence of metachronous primary GC was 6.5% (95%CI: 4.1-10.4). The incidence of metachronous primary GC during the follow-up period was 2.31 per 100 person-years. The frequencies of severe gastric atrophy and macrocytosis at the timing of ER were significantly higher in patients with than without metachronous primary GC (91.7% vs. 73.2%, p = 0.0422, 20.8% vs. 5.2%, p = 0.0046, respectively). Severe gastric atrophy was associated with the development of metachronous primary GC (sex-and-age adjusted hazard ratio (HR) [95%CI] = 4.12 [0.95-27.78], p = 0.0093). Macrocytosis was associated with the development of metachronous primary GC (sex-and-age adjusted HR = 4.76 [1.75-13.0], p = 0.0012) and found to be an independent predictor for metachronous primary GC by multivariate Cox proportional hazards analysis (HR [95%CI] = 4.35 [1.60-11.84], p = 0.004). CONCLUSIONS: Severe gastric atrophy and macrocytosis should be noted in the development of metachronous primary GC after ER for esophageal SCC. In particular, macrocytosis at the timing of ER was considered an important predictor. CLINICAL TRIALS REGISTRY NUMBER: UMIN000001676.

Risk factors for liver-related mortality of patients with hepatitis C virus after sustained virologic response to direct-acting antiviral agents.

Background and Aim: The aim of this study was to identify the factors associated with liver-related and non-liver-related mortality of patients with hepatitis C virus (HCV) after sustained virologic response (SVR) to direct-acting antiviral agents (DAAs). Methods: We conducted a retrospective, single-center cohort study of HCV patients cured by DAAs. Results: A total of 330 patients with SVR to DAAs were eligible. The median follow-up period was 3.38 years (inter-quartile range: 2.03-4.58). The cumulative liver-related or non-liver-related mortality rates at 1, 3, and 5 years were 0.00 or 1.29%, 2.87 or 3.60%, and 5.10 or 9.46, respectively. Among the liver-related deaths, 9 of the 10 were from liver cancer. Among the non-liver-related deaths, the most common cause was malignancy. Through multivariate analysis using the Cox proportional hazard model, diabetes mellitus (DM, hazard ratio 13.1, 95% confidence interval 2.81-61.3) and a history of hepatocellular carcinoma (HCC, 12.8, 2.76-59.2), independently predicted liver-related death. No variables were associated with non-liver-related death. Conclusion: Our findings suggest that DM and a history of HCC are risk factors for liver-related mortality of HCV patients cured by DAAs. These results indicate that early management of HCV and HCC surveillance of diabetic patients after SVR are important to increase the chance of survival. Further studies are needed to confirm the association of DM and HCC history with survival.

Updates in the Field of Submucosal Endoscopy.

Submucosal endoscopy (third-space endoscopy) can be defined as an endoscopic procedure performed in the submucosal space. This procedure is novel and has been utilized for delivery to the submucosal space in a variety of gastrointestinal diseases, such as a tumor, achalasia, gastroparesis, and subepithelial tumors. The main submucosal endoscopy includes peroral endoscopic myotomy, gastric peroral endoscopic myotomy, Zenker peroral endoscopic myotomy, submucosal tunneling for endoscopic resection, and endoscopic submucosal tunnel dissection. Submucosal endoscopy has been used as a viable alternative to surgical techniques because it is minimally invasive in the treatment and diagnosis of gastrointestinal diseases and disorders. However, there is limited evidence to prove this. This article reviews the current applications and evidence regarding submucosal endoscopy while exploring the possible future clinical applications in this field. As our understanding of these procedures improves, the future of submucosal endoscopy could be promising in the fields of diagnostic and therapeutic endoscopy.

Prediction of esophagogastric varices associated with oxaliplatin administration.

BACKGROUND: Oxaliplatin is a key drug for the chemotherapy of colorectal cancer; however, it is also known to cause non-cirrhotic portal hypertension. We aimed to identify the characteristics of patients who developed esophagogastric varices (EGVs) after treatment with oxaliplatin. METHODS: This study retrospectively analyzed patients with colorectal cancer who were treated with chemotherapy including oxaliplatin between 2010 and 2016. All patients were evaluated by contrast-enhanced computed tomography (CE-CT) every 3 months both during and after treatment; and endoscopy was performed when appearance of portal hypertension was suspected. RESULTS: A total of 106 patients were divided into two groups: EGV formation (n = 6) and EGV non-formation (n = 100). In the EGV group, platelet counts decreased and the size of the spleen calculated by CT (CT spleen index; CT-SI) increased markedly. The highest area under the receiver operating characteristic curve (AUC) for the change in platelet counts was 0.81 (80% sensitivity and 83% specificity) at 3 months post treatment, and the maximum AUC for CT-SI was 0.89 (79% sensitivity and 83% specificity) at 6 months post treatment. CONCLUSIONS: EGV formation could be predicted by the assessment of platelet counts and spleen size. If progressive splenomegaly and thrombocytopenia are observed not only during but also after completion of the oxaliplatin-containing chemotherapy, EGVs should be confirmed by endoscopy for avoiding subsequent rupture.

Successfully combined therapy of Coca-Cola and endoscopic treatment for a giant diospyrobezoar in the duodenum using the electrosurgical endo-knife and ileus tube.

Video 1Successfully combined therapy of Coca-Cola and endoscopic treatment for a giant diospyrobezoar in the duodenum using the electrosurgical endo-knife and ileus tube.

Redox Regulation in Aging Lungs and Therapeutic Implications of Antioxidants in COPD.

Mammals, including humans, are aerobic organisms with a mature respiratory system to intake oxygen as a vital source of cellular energy. Despite the essentiality of reactive oxygen species (ROS) as byproducts of aerobic metabolism for cellular homeostasis, excessive ROS contribute to the development of a wide spectrum of pathological conditions, including chronic lung diseases such as COPD. In particular, epithelial cells in the respiratory system are directly exposed to and challenged by exogenous ROS, including ozone and cigarette smoke, which results in detrimental oxidative stress in the lungs. In addition, the dysfunction of redox regulation due to cellular aging accelerates COPD pathogenesis, such as inflammation, protease anti-protease imbalance and cellular apoptosis. Therefore, various drugs targeting oxidative stress-associated pathways, such as thioredoxin and N-acetylcysteine, have been developed for COPD treatment to precisely regulate the redox system. In this review, we present the current understanding of the roles of redox regulation in the respiratory system and COPD pathogenesis. We address the insufficiency of current COPD treatment as antioxidants and discuss future directions in COPD therapeutics targeting oxidative stress while avoiding side effects such as tumorigenesis.

Airway basal stem cells reutilize the embryonic proliferation regulator, Tgfß-Id2 axis, for tissue regeneration.

During development, quiescent airway basal stem cells are derived from proliferative primordial progenitors through the cell-cycle slowdown. In contrast, basal cells contribute to adult tissue regeneration by shifting from slow cycling to proliferating and subsequently back to slow cycling. Although sustained proliferation results in tumorigenesis, the molecular mechanisms regulating these transitions remain unknown. Using temporal single-cell transcriptomics of developing murine airway progenitors and genetic validation experiments, we found that TGF-ß signaling decelerated cell cycle by inhibiting Id2 and contributed to slow-cycling basal cell specification during development. In adult tissue regeneration, reduced TGF-ß signaling restored Id2 expression and initiated regeneration. Id2 overexpression and Tgfbr2 knockout enhanced epithelial proliferation; however, persistent Id2 expression drove basal cell hyperplasia that resembled a precancerous state. Together, the TGF-ß-Id2 axis commonly regulates the proliferation transitions in basal cells during development and regeneration, and its fine-tuning is critical for normal regeneration while avoiding basal cell hyperplasia.

A novel mask to prevent aerosolized droplet dispersion in endoscopic procedures during the coronavirus disease pandemic.

ABSTRACT: Endoscopic procedures increase the risk of transmission of severe acute respiratory syndrome coronavirus 2 to medical staff, because aerosols are generated during upper gastrointestinal endoscopy. There have been several reported studies on devices for infection prevention; however, few reports have validated them. Therefore, we developed a novel mask to prevent the diffusion of aerosol droplets from patients undergoing endoscopy.We compared microdroplet dispersion during coughing episodes when using the novel mask with microdroplet dispersion when using the conventional mouthpiece alone.The mean number of microdroplets was significantly smaller in the group that used the novel mask (57.9 ±â€Š122.91 vs 933.6 ±â€Š119.80 droplets; P = .01).The novel mask may aid in reducing the degree of exposure of medical personnel to microdroplets and the risk of subsequent infection.

Risk Factors for Late Rebleeding of Colonic Diverticular Bleeding in Elderly Individuals.

OBJECTIVES: This study aimed to examine the clinical characteristics of colonic diverticular bleeding (CDB) in elderly individuals. METHODS: This retrospective case-control study was conducted at a single tertiary center. A total of 519 patients (356 men and 163 women; mean age of 73.1 ± 12.5 years) with CDB and hospitalized between January 2004 and May 2019 were analyzed. The subjects were divided into two groups: the elderly (274 individuals aged ≥75 years; mean age, 82.1 ± 5.3 years) and non-elderly (245 individuals aged <75 years; mean age, 63.0 ± 10.3 years) groups. Primary outcomes were early and late rebleeding rates, and secondary outcomes were the risk factors for late rebleeding in elderly individuals. Rebleeding occurring within 30 days of hospitalization was defined as early rebleeding, whereas rebleeding occurring after 31 days was defined as late rebleeding. RESULTS: The early rebleeding rates were 30.6% and 33.1% (p = 0.557) in the elderly and non-elderly groups, respectively. The late rebleeding rates were 42.3% and 30.6% (p = 0.005) in the elderly and non-elderly groups, respectively. The 3-year recurrence-free survival was 63.6% in the elderly group and 75.6% in the non-elderly group (log-rank test: p < 0.001). Multivariate analysis revealed the use of non-steroidal anti-inflammatory drugs (NSAIDs) [odds ratio (OR), 3.55], chronic kidney disease (OR, 2.89), and presence of bilateral diverticula (OR, 1.83) as the independent risk factors for late rebleeding in elderly individuals. CONCLUSIONS: Elderly individuals with CDB require careful follow-up even after discharge. Furthermore, it is important to consider discontinuing NSAIDs to prevent rebleeding.

Molecular crosstalk in tracheal development and its recurrence in adult tissue regeneration.

The trachea is a rigid air duct with some mobility, which comprises the upper region of the respiratory tract and delivers inhaled air to alveoli for gas exchange. During development, the tracheal primordium is first established at the ventral anterior foregut by interactions between the epithelium and mesenchyme through various signaling pathways, such as Wnt, Bmp, retinoic acid, Shh, and Fgf, and then segregates from digestive organs. Abnormalities in this crosstalk result in lethal congenital diseases, such as tracheal agenesis. Interestingly, these molecular mechanisms also play roles in tissue regeneration in adulthood, although it remains less understood compared with their roles in embryonic development. In this review, we discuss cellular and molecular mechanisms of trachea development that regulate the morphogenesis of this simple tubular structure and identities of individual differentiated cells. We also discuss how the facultative regeneration capacity of the epithelium is established during development and maintained in adulthood.

Risk factors of interventional radiology/surgery for colonic diverticular bleeding.

BACKGROUND AND AIM: Colonic diverticular bleeding (CDB) stops spontaneously, but sometimes, excessive bleeding does not allow hemostasis and requires interventional radiology (IR)/surgery. We examined risk factors in patients who required IR/surgery for CDB and late recurrent bleeding rate after IR/surgery. METHODS: This retrospective case-control study was conducted at a tertiary center. We included 608 patients who required hospitalization for CDB. Patients were investigated for risk factors using logistic regression analysis. We also investigated early and late recurrent bleeding rates following IR/surgery. RESULTS: In 261 patients (42.9%), the bleeding source was identified, and endoscopic hemostasis was performed; 23 (3.8%) required IR/surgery. In multivariate analysis, shock state with a blood pressure of ≤90 mmHg (P < 0.001; odds ratio [OR], 20.1; 95% confidence interval [CI], 5.08-79.5), positive extravasation on contrast-enhanced computed tomography (P < 0.001; OR 9.5, 95% CI 2.85-31.4), two or more early recurrent bleeding episodes (P = 0.002; OR 7.4, 95% CI 2.14-25.4), and right colon as the source of bleeding (P = 0.023; OR 4.1, 95% CI 1.25-14.0) were independent risk factors requiring IR/surgery. Early recurrent bleeding was observed in 0% and 28.0% patients (P < 0.001) in the IR/surgery and no IR/surgery groups, respectively, whereas late recurrent bleeding rate was observed in 43.4% and 30.7% patients (P = 0.203) in the IR/surgery and no IR/surgery groups, respectively. Four patients who required surgery experienced late recurrent bleeding at a site different from the initial CDB. CONCLUSIONS: Although IR/surgery is an effective hemostatic treatment wherein endoscopic treatment is unsuccessful, late recurrent bleeding cannot be prevented.

Human umbilical cord mesenchymal stem cell-derived extracellular vesicles ameliorate airway inflammation in a rat model of chronic obstructive pulmonary disease (COPD).

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is an incurable and debilitating chronic disease characterized by progressive airflow limitation associated with abnormal levels of tissue inflammation. Therefore, stem cell-based approaches to tackle the condition are currently a focus of regenerative therapies for COPD. Extracellular vesicles (EVs) released by all cell types are crucially involved in paracrine, extracellular communication. Recent advances in the field suggest that stem cell-derived EVs possess a therapeutic potential which is comparable to the cells of their origin. METHODS: In this study, we assessed the potential anti-inflammatory effects of human umbilical cord mesenchymal stem cell (hUC-MSC)-derived EVs in a rat model of COPD. EVs were isolated from hUC-MSCs and characterized by the transmission electron microscope, western blotting, and nanoparticle tracking analysis. As a model of COPD, male Sprague-Dawley rats were exposed to cigarette smoke for up to 12 weeks, followed by transplantation of hUC-MSCs or application of hUC-MSC-derived EVs. Lung tissue was subjected to histological analysis using haematoxylin and eosin staining, Alcian blue-periodic acid-Schiff (AB-PAS) staining, and immunofluorescence staining. Gene expression in the lung tissue was assessed using microarray analysis. Statistical analyses were performed using GraphPad Prism 7 version 7.0 (GraphPad Software, USA). Student's t test was used to compare between 2 groups. Comparison among more than 2 groups was done using one-way analysis of variance (ANOVA). Data presented as median ± standard deviation (SD). RESULTS: Both transplantation of hUC-MSCs and application of EVs resulted in a reduction of peribronchial and perivascular inflammation, alveolar septal thickening associated with mononuclear inflammation, and a decreased number of goblet cells. Moreover, hUC-MSCs and EVs ameliorated the loss of alveolar septa in the emphysematous lung of COPD rats and reduced the levels of NF-κB subunit p65 in the tissue. Subsequent microarray analysis revealed that both hUC-MSCs and EVs significantly regulate multiple pathways known to be associated with COPD. CONCLUSIONS: In conclusion, we show that hUC-MSC-derived EVs effectively ameliorate by COPD-induced inflammation. Thus, EVs could serve as a new cell-free-based therapy for the treatment of COPD.

Tip-in endoscopic mucosal resection for large colorectal sessile polyps.

BACKGROUND: Tip-in endoscopic mucosal resection (EMR) is a modified EMR technique using which en bloc resection of large colorectal sessile polyps can be performed; however, its usefulness for colorectal sessile polyps of > 20 mm has not been reported. This study examined treatment outcomes of tip-in and conventional EMR for large colorectal sessile polyps of ≥ 20 mm. METHODS: This was a retrospective case-control study conducted at a single tertiary center in Japan. Subjects included those with large colorectal sessile polyps of ≥ 20 mm, excluding pedunculated-type polyps, who underwent endoscopic resection between January 2010 and January 2019. The primary outcome was endoscopic treatment outcomes when using tip-in and conventional EMR, and the secondary outcome was the local recurrence rate after endoscopic treatment. RESULTS: Forty-three colorectal lesions were treated using tip-in EMR and 83 using conventional EMR. Tip-in EMR had a significantly higher en bloc resection rate (90.7% vs. 69.8.%), and significantly shorter treatment duration (6.64 ± 0.64 min vs. 10.47 ± 0.81 min) than conventional EMR. However, for lesions > 30 mm, en bloc resection rate was 50.0% and 52.6% for tip-in and conventional EMR, respectively, indicating no significant difference. Perforation rates with tip-in and conventional EMR were 4.6% and 3.6%, respectively, indicating no significant difference. Local recurrence was examined in 80 cases who were followed up for > 6 months after endoscopic resection; recurrence rate was 0% and 7.0% in tip-in and conventional EMR cases, respectively, without significance difference. CONCLUSIONS: Tip-in EMR showed high en-block resection rate, particularly in polyps of < 30 mm, and no residual tumor was found. This technique is a potential endoscopic treatment alternative for large colorectal sessile polyps of ≥ 20 mm.

Non-tuberculous Mycobacterial Pseudo-outbreak of an Intestinal Culture Specimen Caused by a Water Tap in an Endoscopy Unit.

Objective Gastrointestinal lesions of non-tuberculous mycobacteria (NTM) are regarded as opportunistic infections. A large number of positive specimens of NTM were identified in an intestinal fluid culture in the endoscopy unit and it was considered to be a pseudo-outbreak. Methods We reviewed the hospital, laboratory, and colonoscopy records of 263 consecutive patients whose intestinal fluids were analyzed for a mycobacterial culture by colonoscopy at St. Marianna University Hospital, between January 2009 and December 2018. The endoscopy reprocessing procedures were reviewed and samples of water used in the endoscopy unit were cultured. Results An intestinal fluid culture of 154 (58.6%) patients tested positive for NTM (M. intracellulare; 125 cases, M. gordonae; 14 cases, M. avium; 4 cases, M. abscessus; 3 cases, and 8 other cases). In 182 cases (69.2%), an intestinal mucosal culture was performed simultaneously with a fluid culture and tested positive for NTM in 2 cases. Next, we examined the endoscopy unit for any possible environmental contamination. NTM were detected in the tap water used to prepare the antifoaming solution in the endoscopy unit. The water faucets in the endoscopy unit were considered to be the source of the contamination of NTMs. Conclusion We observed that a large number of cases tested positive due to contaminated water that had been used in an endoscopy unit, thus leading to a pseudo-outbreak of NTM.

Intra-abdominal bleeding as a rare complication after colonic endoscopic mucosal resection in a patient taking direct oral anticoagulants.

We describe the case of an 84-year old female who was taking rivaroxaban 30 mg/day and had a medical history of atrial fibrillation. She underwent endoscopic mucosal resection of a 5-mm adenoma located in the hepatic flexure of the transverse colon. Following the procedure, she developed gradually intensifying abdominal pain, with the appearance of small amount of blood in the feces. For that reason, she visited our facility on the 5th day post-endoscopic mucosal resection. At the time of the visit, contrast-enhanced abdominal computed tomography revealed no extravasation or free air; however, bloody ascites was confirmed in the peritoneal cavity. Thus, the patient was diagnosed with post-endoscopic mucosal resection intra-abdominal hemorrhage and hospitalized the same day. After admission, rivaroxaban was discontinued and patient condition monitored. Because subsequent abdominal computed tomography revealed no distinct increase in bloody ascites, no interventional radiological or surgical procedure was performed, and the patient was discharged after providing only conservative treatment. While hemorrhage and perforation are the main complications after colonic endoscopic mucosal resection, so far, there have been a few reports on the occurrence of intra-abdominal hemorrhage following endoscopic mucosal resection. Emergency treatment is sometimes required in patients with intra-abdominal hemorrhage. It is important to keep in mind that this complication, although very rare, may occur, particularly in patients taking anticoagulants.

Delayed perforation after endoscopic band ligation for colonic diverticular hemorrhage.

A 77-year-old woman presented with the chief complaint of large amounts of hematochezia. Contrast-enhanced computed tomography (CT) revealed extravasation of contrast medium from the diverticula in the sigmoid colon; therefore, upon diagnosis of sigmoid colonic diverticular hemorrhage, she was immediately admitted to our hospital. Emergency colonoscopy revealed active bleeding from the diverticula in the sigmoid colon; hemostasis was achieved with endoscopic band ligation (EBL). However, 4 days later, she suddenly developed severe abdominal pain while defecation, prompting the requirement for obtaining a CT scan, which revealed intraabdominal free air, and delayed perforation after EBL was diagnosed. Emergency surgery was immediately performed; the perforation site was closed with sutures. EBL is useful in achieving hemostasis for colonic diverticular hemorrhage; however, it carries the risk of serious complications, such as delayed perforation, which require surgery. Although EBL is useful to achieve hemostasis for diverticular hemorrhage in the colon, it is preferable to carefully judge its indication owing to the risk of serious complications.

Notch signaling in the mammalian respiratory system, specifically the trachea and lungs, in development, homeostasis, regeneration, and disease.

The respiratory system has ideal tissue structure and cell types for efficient gas exchange to intake oxygen and release carbon dioxide. This complex system develops through orchestrated intercellular signaling among various cell types, such as club, ciliated, basal, neuroendocrine, AT1, AT2, endothelial, and smooth muscle cells. Notch signaling is a highly conserved cell-cell signaling pathway ideally suited for very short-range cellular communication because Notch signals are transmitted by direct contact with an adjacent cell. Enthusiastic efforts by Notch researchers over the last two decades have led to the identification of critical roles of this signaling pathway during development, homeostasis, and regeneration of the respiratory system. The dysregulation of Notch signaling results in a wide range of respiratory diseases such as pulmonary artery hypertension (PAH), chronic obstructive pulmonary disease (COPD), interstitial pulmonary fibrosis (IPF), and lung cancer. Thus, a deep understanding of the biological functions of Notch signaling will help identify novel treatment targets in various respiratory diseases.

Unique Biological Activity and Potential Role of Monomeric Laminin-γ2 as a Novel Biomarker for Hepatocellular Carcinoma: A Review.

Laminin (Ln)-332 consists of α3, ß3, and γ2 chains, which mediate epithelial cell adhesion to the basement membrane. Ln-γ2, a component of Ln-332, is frequently expressed as a monomer in the invasion front of several types of malignant tissues without simultaneous expression of Ln-α3 and/or Ln-ß3 chains. Moreover, monomeric Ln-γ2 induces tumor cell proliferation and migration in vitro. These unique biological activities indicate that monomeric Ln-γ2 could be a candidate biomarker for early cancer surveillance. However, the present immune method for monomeric Ln-γ2 detection can only predict its expression, since no antibody that specifically reacts with monomeric γ2, but not with heterotrimeric γ2 chain, is commercially available. We have, therefore, developed monoclonal antibodies to specifically detect monomeric Ln-γ2, and devised a highly sensitive method to measure serum monomeric Ln-γ2 levels using a fully automated chemiluminescent immunoassay (CLIA). We evaluated its diagnostic value in sera from patients with several digestive cancers, including hepatocellular carcinoma (HCC), and found serum monomeric Ln-γ2 to be a clinically available biomarker for HCC surveillance. The combination of monomeric Ln-γ2 and prothrombin induced by Vitamin K Absence II (PIVKA-II) may be more sensitive for clinical diagnosis of HCC than any currently used combination.