iPSC-derived mesenchymal cells that support alveolar organoid development

肺胞オルガノイドをつくることができるヒトiPS細胞由来間葉細胞の作成. 京都大学プレスリリース. 2022-10-12.Mesenchymal cells are necessary for organ development. In the lung, distal tip fibroblasts contribute to alveolar and airway epithelial cell differentiation and homeostasis. Here, we report a method for generating human induced pluripotent stem cell (iPSC)-derived mesenchymal cells (iMESs) that can induce human iPSC-derived alveolar and airway epithelial lineages in organoids via epithelial-mesenchymal interaction, without the use of allogenic fetal lung fibroblasts. Through a transcriptome comparison of dermal and lung fibroblasts with their corresponding reprogrammed iPSC-derived iMESs, we found that iMESs had features of lung mesenchyme with the potential to induce alveolar type 2 (AT2) cells. Particularly, RSPO2 and RSPO3 expressed in iMESs directly contributed to AT2 cell induction during organoid formation. We demonstrated that the total iPSC-derived alveolar organoids were useful for characterizing responses to the influenza A (H1N1) virus and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, demonstrating their utility for disease modeling

On-chip genotoxic bioassay based on bioluminescence reporter system using three-dimensional microfluidic network

Microchip-based genotoxic bioassay using sensing Escherichia coli strains has been performed. In this method, the assay was conducted in three-dimensional microfluidic network constructed by a silicon perforated microwell array chip and two poly(dimethylsiloxane) (PDMS) multi-microchannel chips. The sensing strains having firefly luciferase reporter gene under transcriptional control of umuD as an SOS promoter were put into the channels on one of the PDMS chips and immobilized in the silicon microwells. Samples containing genotoxic substances and substrates for luciferase were into the channels on the other PDMS chip. The optimum conditions of the assay in the on-chip format have been investigated using mitomycin C (MMC) as a genotoxic substance. As a result, the dose-dependence of bioluminescence intensity was obtained at once on the chip. Additionally, the response ratios of the bioluminescence between mutagen- and non-induced strains were successfully enhanced by improving the on-chip assay methods and conditions. Several well-known genotoxic substances were subjected to the on-chip assay, and were detected with the detection limits comparable to those in the conventional method with reduced time

Evaluation of a rapid coliform detection kit from clinical mastitis milk using colloidal gold nanoparticle-based immunochromatographic strips

The accurate identification of mastitis‐causing bacteria assists in effective management by both dairy farmers and veterinarians and can be used to implement the selective use of antimicrobials for treatment. The purpose of this study was to evaluate the ability of our developed anti–ribosomal protein-L7/L12 antibody–coated immunochromatographic strip (ICS) test to detect coliforms in milk by comparing the results with the bacteriological culture method. We investigated the performance of the ICS test as compared with the bacteriological culture method using 308 milk samples from clinical bovine mastitis. First, to determine the optimal ICS test cutoff point for detecting coliform mastitis, we developed a receiver-operating characteristic curve. The result showed that the cutoff point was at 0.5 of our index. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value of the ICS test were 81.3%, 84.8%, 69.2%, and 91.54%, respectively. As the clinical signs increased in severity, the F-measure, a weighted harmonic mean of the sensitivity and overall PPV performance, increased. Because it is especially important to treat clinical mastitis appropriately in the early stages of detection, the ICS test, which can be used by both dairy farmers and veterinarians on dairy farms, is considered to be a useful tool for detecting coliform mastitis, which often presents with severe signs

Serum cystatin C can be used as a marker of renal function even in patients with intestinal urinary diversion

Objective: Recently, serum cystatin C (CysC) has been used as a novel marker of renal function. However, there is a lack of data on CysC levels in patients with intestinal urinary diversion (UD). Here we report CysC levels in such patients. Methods: We prospectively observed 38 patients who were diagnosed with bladder cancer and subsequently treated with radical cystectomy and UD at our institution in 2012 and 2013. Serum creatinine (sCr) and CysC were obtained optionally at the same time at least 1 month after radical cystectomy and UD. Results: The median CysC and sCr concentrations were 1.12 mg/L (range 0.75–2.47 mg/L) and 0.99 mg/dL (range 0.61–2.22 mg/dL), respectively. The median estimated concentrations of glomerular filtration rate (GFR) based on CysC (eGFRcys) and GFR based on creatinine (eGFRcreat) were 61.08 mL/min/1.73 m2 (range 22.64–99.89 mL/min/1.73 m2) and 58.01 mL/min/1.73 m2 (range 23.48–91.82 mL/min/1.73 m2), respectively. CysC had a significant correlation with sCr (r = 0.8607, p < 0.0001) and eGFRcreat (r = −0.8993, p < 0.0001). eGFRcys also had a significant correlation with eGFRcreat (r = 0.8104, p < 0.0001). Conclusion: The correlation between CysC and sCr was strong and the correlation coefficient was equivalent to that in patients without UD. The results suggest that CysC is not affected by UD and can be used as a marker of renal function similarly to sCr in patients with UD