Background: Reactive oxygen species (ROS) and inflammation are reported to have a fundamental role in the pathogenesis of ischemia-reperfusion (IR) injury, a leading cause of acute kidney injury. The present study investigated the role of pyruvate dehydrogenase kinase 4 (PDK4) in ROS production and inflammation following IR injury. Methods: We used a streptozotocin-induced diabetic C57BL6/J mouse model, which was subjected to IR by clamping both renal pedicles. Cellular apoptosis and inflammatory markers were evaluated in NRK-52E cells and mouse primary tubular cells after hypoxia and reoxygenation using a hypoxia work station. Results: Following IR injury in diabetic mice, the expression of PDK4, rather than the other PDK isoforms, was induced with a marked increase in pyruvate dehydrogenase E1α (PDHE1α) phosphorylation. This was accompanied by a pronounced ROS activation, as well as tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-1β (IL-1β), and monocyte chemoattractant protein-1 (MCP-1) production. Notably, sodium dichloroacetate (DCA) attenuated renal IR injury-induced apoptosis which can be attributed to reducing PDK4 expression and PDHE1α phosphorylation levels. DCA or shPdk4 treatment reduced oxidative stress and decreased TNF-α, IL-6, IL-1β, and MCP-1 production after IR or hypoxia-reoxygenation injury. Conclusion PDK4 inhibition alleviated renal injury with decreased ROS production and inflammation, supporting a critical role for PDK4 in IR mediated damage. This result indicates another potential target for reno-protection during IR injury; accordingly, the role of PDK4 inhibition needs to be comprehensively elucidated in terms of mitochondrial function during renal IR injury.

Objective: To investigate whether reader training improves the performance and agreement of radiologists in interpreting unenhanced breast magnetic resonance imaging (MRI) scans using diffusion-weighted imaging (DWI). Materials and Methods: A study of 96 breasts (35 cancers, 24 benign, and 37 negative) in 48 asymptomatic women was performed between June 2019 and October 2020. High-resolution DWI with b-values of 0, 800, and 1200 sec/mm 2 was performed using a 3.0-T system. Sixteen breast radiologists independently reviewed the DWI, apparent diffusion coefficient maps, and T1-weighted MRI scans and recorded the Breast Imaging Reporting and Data System (BI-RADS) category for each breast. After a 2-h training session and a 5-month washout period, they re-evaluated the BI-RADS categories. A BI-RADS category of 4 (lesions with at least two suspicious criteria) or 5 (more than two suspicious criteria) was considered positive.The per-breast diagnostic performance of each reader was compared between the first and second reviews. Inter-reader agreement was evaluated using a multi-rater κ analysis and intraclass correlation coefficient (ICC). Results: Before training, the mean sensitivity, specificity, and accuracy of the 16 readers were 70.7% (95% confidence interval [CI]: 59.4–79.9), 90.8% (95% CI: 85.6–94.2), and 83.5% (95% CI: 78.6–87.4), respectively. After training, significant improvements in specificity (95.2%; 95% CI: 90.8–97.5; P = 0.001) and accuracy (85.9%; 95% CI: 80.9–89.8; P = 0.01) were observed, but no difference in sensitivity (69.8%; 95% CI: 58.1–79.4; P = 0.58) was observed. Regarding inter-reader agreement, the κ values were 0.57 (95% CI: 0.52–0.63) before training and 0.68 (95% CI: 0.62–0.74) after training, with a difference of 0.11 (95% CI: 0.02–0.18; P = 0.01). The ICC was 0.73 (95% CI: 0.69–0.74) before training and 0.79 (95% CI: 0.76–0.80) after training (P = 0.002). Conclusion Brief reader training improved the performance and agreement of interpretations by breast radiologists using unenhanced MRI with DWI.

γδ T cells are a rare and unique prototype of T cells that share properties with natural killer cells in secondary lymphoid organs. Although many studies have revealed the function and importance of adult-derived γδ T cells in cancer biology and regenerative medicine, the low numbers of these cells hamper their application as therapeutic cell sources in the clinic. To solve this problem, pluripotent stem cell-derived γδ T cells are considered alternative cell sources; however, few studies have reported the generation of human pluripotent stem cell-derived γδ T cells. In the present study, we investigated whether lymphoid lineage γδ T cells were successfully generated from human pluripotent stem cells via hemogenic endothelium under defined culture conditions. Our results revealed that pluripotent stem cells successfully generated γδ T cells with an overall increase in transcriptional activity of lymphoid lineage genes and cytolytic factors, indicating the importance of the optimization of culture conditions in generating lymphoid lineage γδ T cells. We uncovered an initial step in differentiating γδ T cells that could be applied to basic and translational investigations in the field of cancer biology. Based on our result, we will develop an appropriate method to purify γδ T cells with functionality and it helpful for the study of basic mechanism of γδ T cells in pathophysiologic condition as well as clinic application.

Purpose: K-MASTER project is a Korean national precision medicine platform that screened actionable mutations by analyzing next-generation sequencing (NGS) of solid tumor patients. We compared gene analyses between NGS panel from the K-MASTER project and orthogonal methods. Materials and Methods: Colorectal, breast, non–small cell lung, and gastric cancer patients were included. We compared NGS results from K-MASTER projects with those of non-NGS orthogonal methods (KRAS, NRAS, and BRAF mutations in colorectal cancer [CRC]; epidermal growth factor receptor [EGFR], anaplastic lymphoma kinase [ALK] fusion, and reactive oxygen species 1 [ROS1] fusion in non–small cell lung cancer [NSCLC], and Erb-B2 receptor tyrosine kinase 2 (ERBB2) positivity in breast and gastric cancers). Results: In the CRC cohort (n=225), the sensitivity and specificity of NGS were 87.4% and 79.3% (KRAS); 88.9% and 98.9% (NRAS); and 77.8% and 100.0% (BRAF), respectively. In the NSCLC cohort (n=109), the sensitivity and specificity of NGS for EGFR were 86.2% and 97.5%, respectively. The concordance rate for ALK fusion was 100%, but ROS1 fusion was positive in only one of three cases that were positive in orthogonal tests. In the breast cancer cohort (n=260), ERBB2 amplification was detected in 45 by NGS. Compared with orthogonal methods that integrated immunohistochemistry and in situ hybridization, sensitivity and specificity were 53.7% and 99.4%, respectively. In the gastric cancer cohort (n=64), ERBB2 amplification was detected in six by NGS. Compared with orthogonal methods, sensitivity and specificity were 62.5% and 98.2%, respectively. Conclusion The results of the K-MASTER NGS panel and orthogonal methods showed a different degree of agreement for each genetic alteration, but generally showed a high agreement rate.

The importance of adopting healthy exercise routines has been repeatedly emphasized to individuals with diabetes mellitus (DM). However, knowledge about the risk of exercise-induced hypoglycemia is limited. Regular exercise reduces and delays the onset of DM-related complications particularly in individuals who already have DM. However, an excessive exercise can lead to hypoglycemia. Excessive exercise in the evening can cause hypoglycemia while sleeping. Furthermore, if individuals with DM want to have a greater amount of exercise, the exercise duration rather than intensity must be increased. In weight resistance exercises, it is beneficial to first increase the number of repetitions, followed by the number of sets and gradually the weight of resistance. When performing intermittent high-intensity training within a short time period, hypoglycemia may develop for an extended period after exercise. In addition to adjusting exercise regimens, the medication doses must be modified accordingly. Delaying exercise, adjusting the number of snacks consumed prior to exercise, reducing insulin dose before exercise, and injecting insulin into the abdomen rather than the limbs prevent exercise-induced hypoglycemia prior to a spontaneous exercise. Ultimately, with personal knowledge on how to prevent hypoglycemia, the effects of exercise can be maximized in individuals with DM, and a healthy lifestyle can prevent future complications.

The chemical investigation of the 90% EtOH extract from Cicadidae Periostracum led to the isolation and identification of seven known N-acetyldopamine dimers (1-7). These compounds were identified by comparing mass spectrometry data and NMR spectroscopic data with those previously reported. In this study, complete interpretation of 1D and 2D NMR data of 1 and 2 were reported for the first time. In addition, compounds 3 and 4 were isolated from this material for the first time. All isolates were obtained as racemic mixtures, as confirmed by chiral HPLC. Furthermore, we evaluated the neuroprotective activities of compounds 1–7 and found that compounds 1, 5, and 6 significantly attenuated rotenone-induced death of SH-SY5Yneuroblastoma cells at a concentration of 100 μM. Parallel to this result, compounds 3 and 6 displayed antioxidant effects in the cytoplasm, as determined by CM-H2DCFDA fluorescence intensity, while compounds 1 and 5 showed antioxidant effects in the mitochondria, as assessed by MitoSox fluorescence intensity. Overall, these results suggest that some of these compounds protect neuroblastoma cells by ameliorating the release of reactive oxygen species. Further studies are warranted to elucidate the underlying mechanisms by which these compounds exhibit antioxidant and neuroprotective actions.

We used a heterozygous gene deletion library of fission yeasts comprising all essential and non-essential genes for a microarray screening of target genes of the antifungal terbinafine, which inhibits ergosterol synthesis via the erg1 enzyme. We identified 14 heterozygous strains corresponding to 10 non-essential [7 ribosomal-protein (RP) coding genes, spt7, spt20, and elp2] and 4 essential genes (tif302, rpl2501, rpl31, and erg1). Expectedly, their erg1 mRNA and protein levels had decreased compared to the control strain SP286. When we studied the action mechanism of the non-essential target genes using cognate haploid deletion strains, knockout of SAGA-subunit genes caused a down-regulation in erg1 transcription compared to the control strain ED668. However, knockout of RP genes conferred no susceptibility to ergosterol-targeting antifungals. Surprisingly, the RP genes participated in the erg1 transcription as components of repressor complexes as observed in a comparison analysis of the experimental ratio of erg1 mRNA. To understand the action mechanism of the interaction between the drug and the novel essential target genes, we performed isobologram assays with terbinafine and econazole (or cycloheximide). Terbinafine susceptibility of the tif302 heterozygous strain was attributed to both decreased erg1 mRNA levels and inhibition of translation. Moreover, Tif302 was required for efficacy of both terbinafine and cycloheximide. Based on a molecular modeling analysis, terbinafine could directly bind to Tif302 in yeasts, suggesting Tif302 as a potential off-target of terbinafine. In conclusion, this genome-wide screening system can be harnessed for the identification and characterization of target genes under any condition of interest.

Purpose: Next-generation sequencing (NGS) can facilitate precision medicine approaches in metastatic colorectal cancer (mCRC) patients. We investigated the molecular profiling of Korean mCRC patients under the K-MASTER project which was initiated in June 2017 as a nationwide precision medicine oncology clinical trial platform which used NGS assay to screen actionable mutations. Materials and Methods: As of 22 January 2020, total of 994 mCRC patients were registered in K-MASTER project. Targeted sequencing was performed using three platforms which were composed of the K-MASTER cancer panel v1.1 and the SNUH FIRST Cancer Panel v3.01. If tumor tissue was not available, cell-free DNA was extracted and the targeted sequencing was performed by Axen Cancer Panel as a liquid biopsy. Results: In 994 mCRC patients, we found 1,564 clinically meaningful pathogenic variants which mutated in 71 genes. Anti-EGFR therapy candidates were 467 patients (47.0%) and BRAF V600E mutation (n=47, 4.7%), deficient mismatch repair/microsatellite instability–high (n=15, 1.5%), HER2 amplifications (n=10, 1.0%) could be incorporated with recently approved drugs. The patients with high tumor mutation burden (n=101, 12.7%) and DNA damaging response and repair defect pathway alteration (n=42, 4.2%) could be enrolled clinical trials with immune checkpoint inhibitors. There were more colorectal cancer molecular alterations such as PIK3CA, KRAS G12C, atypical BRAF, and HER2 mutations and even rarer but actionable genes that approved or ongoing clinical trials in other solid tumors. Conclusion K-MASTER project provides an intriguing background to investigate new clinical trials with biomarkers and give therapeutic opportunity for mCRC patients.

The importance of adopting healthy exercise routines has been repeatedly emphasized to individuals with diabetes mellitus (DM). However, knowledge about the risk of exercise-induced hypoglycemia is limited. Regular exercise reduces and delays the onset of DM-related complications particularly in individuals who already have DM. However, an excessive exercise can lead to hypoglycemia. Excessive exercise in the evening can cause hypoglycemia while sleeping. Furthermore, if individuals with DM want to have a greater amount of exercise, the exercise duration rather than intensity must be increased. In weight resistance exercises, it is beneficial to first increase the number of repetitions, followed by the number of sets and gradually the weight of resistance. When performing intermittent high-intensity training within a short time period, hypoglycemia may develop for an extended period after exercise. In addition to adjusting exercise regimens, the medication doses must be modified accordingly. Delaying exercise, adjusting the number of snacks consumed prior to exercise, reducing insulin dose before exercise, and injecting insulin into the abdomen rather than the limbs prevent exercise-induced hypoglycemia prior to a spontaneous exercise. Ultimately, with personal knowledge on how to prevent hypoglycemia, the effects of exercise can be maximized in individuals with DM, and a healthy lifestyle can prevent future complications.

The chemical investigation of the 90% EtOH extract from Cicadidae Periostracum led to the isolation and identification of seven known N-acetyldopamine dimers (1-7). These compounds were identified by comparing mass spectrometry data and NMR spectroscopic data with those previously reported. In this study, complete interpretation of 1D and 2D NMR data of 1 and 2 were reported for the first time. In addition, compounds 3 and 4 were isolated from this material for the first time. All isolates were obtained as racemic mixtures, as confirmed by chiral HPLC. Furthermore, we evaluated the neuroprotective activities of compounds 1–7 and found that compounds 1, 5, and 6 significantly attenuated rotenone-induced death of SH-SY5Yneuroblastoma cells at a concentration of 100 μM. Parallel to this result, compounds 3 and 6 displayed antioxidant effects in the cytoplasm, as determined by CM-H2DCFDA fluorescence intensity, while compounds 1 and 5 showed antioxidant effects in the mitochondria, as assessed by MitoSox fluorescence intensity. Overall, these results suggest that some of these compounds protect neuroblastoma cells by ameliorating the release of reactive oxygen species. Further studies are warranted to elucidate the underlying mechanisms by which these compounds exhibit antioxidant and neuroprotective actions.