Biology subjects

Jung, H. S.

Publications and source records attributed to Jung, H. S..

3 recordsLinked to original sources

bioRxiv2023

PTP1B phosphatase puts a brake on iPSC-derived neutrophil motility and antimicrobial function

Neutrophils are rapidly recruited to sites of infection and are critical for pathogen clearance. Neutropenic patients are at high risk for fungal and bacterial infections and can benefit from granulocyte transfusion therapy. Human induced pluripotent stem cells (iPSCs) could provide a robust source of neutrophil-like cells for infusion as they can be generated in large quantities and do not require a donor. However, dampened intracellular signaling limits their cellular activation and response. Here, we show that we can engineer iPSC-derived neutrophils (iNeutrophils) for enhanced motility and anti-microbial functions. Deletion of the PTP1B phosphatase increased iNeutrophil PI3K and ERK signaling and was associated with increased F-actin polymerization, cell migration and phagocytosis. PTP1B deletion also increased production of inflammatory cytokines, including the neutrophil chemoattractant IL-8. Furthermore, PTP1B-KO iNeutrophils displayed a highly activated morphology and were more responsive to the fungal pathogen Aspergillus fumigatus. KO iNeutrophils efficiently migrated to and swarmed hyphae resulting in inhibition of fungal growth. Taken together, deletion of the PTP1B phosphatase removes the "brakes" on iPSC-derived intracellular signaling and neutrophil function. Key pointsDeletion of PTP1B increases iPSC-derived neutrophil intracellular signaling to improve motility and phagocytosis. Deletion of PTP1B enhances iPSC-derived neutrophil swarming response and ability to inhibit fungal growth.

immunology↗

bioRxiv2020

Newly developed silicone airway stent (GINA stent): Mechanical characteristics and performance evaluation in pigs

OBJECTIVESCentral airway obstruction (CAO) is caused by various malignant and benign processes. Surgery is a preferred option for CAO, but if not possible, bronchoscopic treatment could be performed. Recently, bronchoscopic treatments have been improved. Particularly in airway stents, new attempts are being made to overcome the existing shortcomings of stents (migration, mucostasis, and granulation tissue formation). We recently developed a new silicone airway stent (GINA stent). The GINA stent has anti-migration design, dynamic structure enabling reduction of stent cross-sectional area, and radiopaqueness. We sought to evaluate mechanical characteristics and performance of our novel GINA stent in a pig tracheal stenosis model. METHODSAll tests were performed by comparing GINA stent [outer diameter (OD, mm) 14, length (L, mm) 55] with Dumon stent (OD14L50). Mechanical tests were done using digital force gage to determine the anti-migration force, expansion force, and flexibility. Short-term (3 weeks) performance was evaluated after stent implantations [GINA (n = 4) vs. Dumon (n = 3)] in a pig model of tracheal stenosis. RESULTSMechanical properties outcomes for GINA vs. Dumon: anti-migration force [18.4 vs. 12.8 Newton (N)]; expansion force (11.9 vs. 14.5 N); flexibility (3.1 vs. 4.5 N). Short-term (3 weeks) GINA vs. Dumon performances: mucus retention (0/4 vs. 0/3); granulation tissue formation (0/4 vs. 0/3); migration (1/4 vs. 2/3). CONCLUSIONSGINA stent demonstrated better mechanical properties than Dumon stent with a stent performance not inferior to Dumon stent.

physiology↗

bioRxiv2019

Trajectories of change after a health-education program in Japan

BackgroundHealth education can benefit people with chronic diseases. However, in previous research those benefits were small, and reinforcement to maintain them was not effective. A possible explanation is that the benefits appeared to be small and reinforcement appeared to be ineffective because those analyses mixed data from two latent groups: one group of people who needed reinforcement and one group of people who did not. The hypothesis is that mixing the data from those two different groups caused the true effects to be \"diluted.\"\n\nMethodsTo test that hypothesis we used data from the Chronic Disease Self-Management Program in Japan, focusing on anxiety, depression, and patient-physician communication. To identify latent trajectories of change after the program, we used growth-mixture modeling. Then, to find out which baseline factors were associated with trajectory-group membership, we used logistic regression.\n\nResultsGrowth-mixture modeling revealed two trajectories - two groups that were defined by distinct patterns of change after the program. One of those patterns was improvement followed by backsliding: decay of impact. On anxiety and depression the decay of impact was large enough to be clinically important, and its prevalence was as high as 50%. Next, logistic regression analysis revealed that being in the decay-of-impact group could be predicted from multimorbidity, low self-efficacy, and high scores on anxiety or depression at baseline. In addition, one unexpected finding was an association between multimorbidity and better patient-physician communication.\n\nConclusionsThese results support the hypothesis that previous findings (i.e. apparently small effect sizes and apparently ineffective reinforcement) actually reflect \"dilution\" of large effects, which was caused by mixing of data from distinct groups. Specifically, there was one group with decay of impact and one without. Thus, evaluations of health education should include analyses of trajectory-defined groups. These results show how the group of people who are most likely to need reinforcement can be identified even before the educational program begins. Extra attention and reinforcement can then be tailored. They can be focused specifically to benefit the people with the greatest need.

epidemiology↗