Involvement of GAT2/Slc6a13 in hypotaurine uptake at fetal-facing plasma membrane of syncytiotrophoblasts at mid-to-late gestation in rats and mice.

INTRODUCTION: Hypotaurine, a precursor to taurine, is known for its antioxidant properties and is prominently present in fetal plasma and the placenta. Our previous research revealed that ezrin-knockout mice experience fetal growth retardation, coinciding with reduced hypotaurine levels in fetal plasma. This study aims to elucidate the expression and role of hypotaurine transporters within the placenta. METHODS: We employed quantitative RT-PCR to measure mRNA expression of GAT transporter family members in the placenta during mid-to-late gestation. LC/MS/MS was used to analyze the distribution of hypotaurine in different placental subregions. Immunohistochemistry was utilized to examine the localization of GAT2 in mice. Placental hypotaurine uptake from fetal circulation was studied via umbilical perfusion in rats. RESULTS: Among hypotaurine transporters, GAT2 exhibited increased mRNA and protein expression in murine placenta during mid-to-late gestation. Notably, GAT2/Slc6a13 mRNA and hypotaurine were most concentrated in the labyrinth of murine placenta. In contrast, enzymes responsible for hypotaurine synthesis, such as cysteine dioxygenase, cysteine sulfinic acid decarboxylase, and 2-aminoethanethiol dioxygenase, showed minimal expression in the labyrinth. These findings suggest that GAT2 is a key determinant of hypotaurine levels in the placental labyrinth. Immunohistochemical examination unveiled that GAT2 was predominantly localized on the fetal-facing plasma membrane within syncytiotrophoblasts, which co-localized with ezrin. In rat umbilical perfusion experiments, the GAT2/3 and TauT inhibitor, SNAP-5114, significantly reduced hypotaurine extraction from fetal circulation to the placenta. DISCUSSION: The results suggest that GAT2 plays a pivotal role in the concentrative uptake of hypotaurine from fetal plasma within syncytiotrophoblasts of the placenta.

Epidemiologic evaluation of pleurisy diagnosed by surgical pleural biopsy using data from a nationwide administrative database.

BACKGROUND: Pleural biopsies for investigating the causes of pleurisy are performed through modalities including needle biopsies, local anesthetic thoracoscopic procedures, and surgery (video-assisted thoracoscopic surgery and open thoracotomy). To date, there have been no large-scale nationwide epidemiological studies regarding pleurisy diagnosed via surgical pleural biopsy. This study examined the epidemiology of pleurisy diagnosed via surgical pleural biopsy in a Japanese nationwide administrative database. METHODS: We evaluated Japanese Diagnosis Procedure Combination data of 24 173 patients who underwent video-assisted thoracoscopic surgery or open thoracotomy and received a diagnosis of pleurisy between April 2014 and March 2020. In addition to pleurisy diagnoses, the patients' clinical information, including age, sex, smoking status (pack-years), dyspnea grade, length of in-hospital stay, and comorbidities, were extracted from the dataset. RESULTS: This study included data from 1699 patients. The most frequent causes of pleurisy were neoplastic diseases (55.9%; malignant mesothelioma 22.5%, lung cancer 15.7%, lymphoma 2.5%), followed by infectious diseases (24.0%; tuberculosis 16.2%, parapneumonic pleural effusion 3.6%, empyema 3.5%, nontuberculous mycobacteriosis 0.5%), collagen vascular diseases (2.8%; rheumatoid arthritis 1.3%, immunoglobulin G4-related diseases 0.7%, systemic lupus erythematosus 0.3%), and paragonimiasis (0.1%). CONCLUSIONS: Neoplastic diseases, including malignant mesothelioma and lung cancer, were frequently and accurately diagnosed as pleurisy via surgical pleural biopsy. The next leading cause was infectious diseases such as mycobacterial infections. Physicians should consider performing surgical biopsy in light of the knowledge regarding the etiology of pleurisy when a definitive diagnosis cannot be made via needle pleural biopsy.

An Autopsy Case of An Acute Exacerbation of Idiopathic Pulmonary Fibrosis Triggered by the Inhalation of a Waterproofing Spray.

An 82-year-old Japanese man with idiopathic pulmonary fibrosis (IPF) experienced dyspnea after using a waterproofing spray in a closed room. He presented with hypoxemia and his chest computed tomography showed additive bilateral diffuse ground-glass attenuation on fibrosis, which was diagnostic of an acute exacerbation of IPF (AE-IPF). Combined treatment with high-dose corticosteroids and immunosuppressants were ineffective, and he later died of respiratory failure. Autopsy findings showed diffuse alveolar damage with honeycombing. His medical history and autopsy histopathology suggested AE-IPF caused by the inhalation of a waterproofing spray.

Combined detection of lymphocyte clonality and MALT1 translocations in bronchoalveolar lavage fluid for diagnosing pulmonary lymphomas.

Diagnosis of pulmonary lymphoma using small tissue samples is difficult and often requires surgical procedures; thus, a less invasive sampling method is desirable. We previously showed that pulmonary mucosa-associated lymphoid tissue (MALT) lymphoma can be diagnosed by detecting MALT lymphoma translocation gene 1 (MALT1) translocations in bronchoalveolar lavage fluid (BALF) cells. Analysis of B-cell clonality based on immunoglobulin heavy chain (IGH) gene rearrangements was also reportedly useful for diagnosing pulmonary lymphoma. The aim of this prospective multicenter study was to evaluate the yet unknown diagnostic potential of combined detection of MALT1 translocations and clonality using BALF. We analyzed B- and T-cell clonality based on IGH and T-cell receptor (TCR) rearrangements together with MALT1 translocations using BALF of patients with clinically suspected pulmonary lymphomas. In total, 39 patients were evaluated and categorized into three groups: B-cell lymphoma, lymphoproliferative disorders, and other diseases. IGH rearrangement detection for B-cell lymphoma diagnosis exhibited sensitivity and specificity of 88.9% and 90.0%, respectively. TCR rearrangements were not observed in patients with B-cell lymphomas. The presence of IGH rearrangements together with the absence of TCR rearrangements indicated 96.0% specificity for the diagnosis of B-cell lymphoma. The sensitivity and specificity of MALT1 translocations for diagnosing MALT lymphoma were 28.6% and 100%, respectively. The combined detection of lymphocyte clonality and MALT1 translocations using BALF is suitable for screening and diagnosis of B-cell lymphomas. Analysis of specific genes such as MALT1 should improve the precision of B-cell lymphoma diagnosis.

Immune checkpoint inhibitors-induced eosinophilic pneumonia: A case report.

A 78-year-old male with renal cell carcinoma was treated with combined immunotherapy of nivolumab and ipilimumab. After four courses of the treatment, a chest computed tomography (CT) revealed newly formed ground-glass opacities (GGOs) in both the lower lung lobes; drug-induced pneumonia was speculated. Eosinophil counts were elevated in both peripheral blood and bronchoalveolar lavage fluid. Both the immune checkpoint inhibitors (ICIs) were discontinued, following which the chest CT findings improved. Based on these findings, a diagnosis of ICI-induced eosinophilic pneumonia was made. Hence, clinicians should be wary of the risk of eosinophilic pneumonia during ICI-anticancer therapy.

Effect of everolimus on the glucose metabolic pathway in mouse skeletal muscle cells (C2C12).

INTRODUCTION: Everolimus selectively inhibits mammalian target of rapamycin complex 1 (mTORC1) and exerts an antineoplastic effect. Metabolic disturbance has emerged as a common and unique side effect of everolimus. OBJECTIVES: We used targeted metabolomic analysis to investigate the effects of everolimus on the intracellular glycometabolic pathway. METHODS: Mouse skeletal muscle cells (C2C12) were exposed to everolimus for 48 h, and changes in intracellular metabolites were determined by capillary electrophoresis time-of-flight mass spectrometry. mRNA abundance, protein expression and activity were measured for enzymes involved in glycometabolism and related pathways. RESULTS: Both extracellular and intracellular glucose levels increased with exposure to everolimus. Most intracellular glycometabolites were decreased by everolimus, including those involved in glycolysis and the pentose phosphate pathway, whereas no changes were observed in the tricarboxylic acid cycle. Everolimus suppressed mRNA expression of enzymes related to glycolysis, downstream of mTOR signaling enzymes and adenosine 5'-monophosphate protein kinases. The activity of key enzymes involved in glycolysis and the pentose phosphate pathway were decreased by everolimus. These results show that everolimus impairs glucose utilization in intracellular metabolism. CONCLUSIONS: The present metabolomic analysis indicates that everolimus impairs glucose metabolism in muscle cells by lowering the activities of glycolysis and the pentose phosphate pathway.

ZEB1 expression is a potential indicator of invasive endometriosis.

INTRODUCTION: Although endometriosis is a benign disease, it shares some features with cancers, such as invasiveness and the potential to metastasize. This study sought to investigate the epithelial-mesenchymal transition status in human endometriotic lesions. MATERIAL AND METHODS: Thirteen endometriosis patients and 10 control women without endometriosis undergoing surgery for benign indications were recruited. We examined the expression of E-cadherin, vimentin, and epithelial-mesenchymal transition-induced transcriptional factors, such as Snail and ZEB1, by immunohistochemistry. We evaluated the expression of each marker in epithelial cells of both endometriotic lesions (ovarian endometrioma, deep infiltrating endometriosis, adenomyosis) and normal endometria. The correlation between ZEB1 expression and serum level of CA125 was also investigated. RESULTS: Immunohistochemical analysis revealed that although E-cadherin, vimentin, and Snail were expressed in epithelia of normal endometria and endometriotic lesions, ZEB1 expression was only expressed in epithelia of endometriotic lesions. Additionally, ZEB1 was most frequently observed in epithelial cells of invasive endometriosis. The endometriosis patients with high serum CA125 level were more likely to have ZEB1-positive lesions. CONCLUSIONS: This is the first observation of ZEB1 expression in epithelial cells of benign disease. The preferential expression of ZEB1 in epithelial cells of endometriotic lesions suggests that these cells may have, at least in part, a higher level of mesenchymal features possibly via ZEB1-driven epithelial-mesenchymal transition than normal endometria and that ZEB1 can be a potential indicator of invasiveness or severity of endometriosis.