Publications by authors named "Taehyun Yoo"

3 Publications

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Potential and efficiency of statistical learning closely intertwined with individuals' executive functions: a mathematical modeling study.

Sci Rep 2020 11 2;10(1):18843. Epub 2020 Nov 2.

Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, Republic of Korea.

Statistical learning (SL) is essential in enabling humans to extract probabilistic regularities from the world. The ability to accomplish ultimate learning performance with training (i.e., the potential of learning) has been known to be dissociated with performance improvement per amount of learning time (i.e., the efficiency of learning). Here, we quantified the potential and efficiency of SL separately through mathematical modeling and scrutinized how they were affected by various executive functions. Our results showed that a high potential of SL was associated with poor inhibition and good visuo-spatial working memory, whereas high efficiency of SL was closely related to good inhibition and good set-shifting. We unveiled the distinct characteristics of SL in relation to potential and efficiency and their interaction with executive functions.
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November 2020

Enhancement of the stability of Mycobacterium tuberculosis recombinant antigen expressed in Escherichia coli using cell lysis additives.

Protein Expr Purif 2019 12 9;164:105453. Epub 2019 Jul 9.

Department of Research and Development, The Korean Institute of Tuberculosis, 168-5 Osongsaengmyeong 4-ro, Heungdeok-gu, Cheongju-si, Chungcheongbuk-do, 28158, Republic of Korea. Electronic address:

Background: Mycobacteria tuberculosis (Mtb), the causative agent of tuberculosis, is a slow-growing bacterium. Expression in Escherichia coli is a widely used method for large-scale production of diagnostic antigenic recombinant proteins. Expression of Mtb antigen in E. coli offers a rapid and, inexpensive alternative to conventional protein synthesis from Mtb. The addition of stabilizing additives during cell lysis or storage of Mtb antigenic protein plays a vital role in enhancing antigen stability. In this study, we evaluated the effects of additives on the stability of Mtb antigens expressed in E. coli.

Methods: Immunodominant Mtb antigens, i.e., CFP-10, Rv3872, TB7.7, and TB9.7, were cloned, and recombinant proteins overexpressed in E. coli were gradually degraded in a time-dependent manner by incubation at 37 °C. Various stabilizing additives during storage or cell lysis before protein purification were investigated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blot analysis.

Results: CFP-10 and Rv3872 were mainly expressed in soluble form. The degraded form of the expressed protein after incubation at 37 °C was easily observed after 1 week. Increased stability was observed in a solution containing glycine for recombinant CFP-10 and Rv3872. TB9.7 was stable in a solution containing trehalose or mannitol. TB7.7 was stable in a solution containing sucrose, glycine, or polyethylene glycol.

Conclusion: Recombinant Mtb antigen stabilization using chemical additives inhibited protein degradation, leading to increased antigen stability and purification efficiency.
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December 2019

Cyclodextrin protects podocytes in diabetic kidney disease.

Diabetes 2013 Nov 8;62(11):3817-27. Epub 2013 Jul 8.

Division of Nephrology and Hypertension, Department of Medicine, University of Miami Miller School of Medicine, Miami, Florida.

Diabetic kidney disease (DKD) remains the most common cause of end-stage kidney disease despite multifactorial intervention. We demonstrated that increased cholesterol in association with downregulation of ATP-binding cassette transporter ABCA1 occurs in normal human podocytes exposed to the sera of patients with type 1 diabetes and albuminuria (DKD(+)) when compared with diabetic patients with normoalbuminuria (DKD(-)) and similar duration of diabetes and lipid profile. Glomerular downregulation of ABCA1 was confirmed in biopsies from patients with early DKD (n = 70) when compared with normal living donors (n = 32). Induction of cholesterol efflux with cyclodextrin (CD) but not inhibition of cholesterol synthesis with simvastatin prevented podocyte injury observed in vitro after exposure to patient sera. Subcutaneous administration of CD to diabetic BTBR (black and tan, brachiuric) ob/ob mice was safe and reduced albuminuria, mesangial expansion, kidney weight, and cortical cholesterol content. This was followed by an improvement of fasting insulin, blood glucose, body weight, and glucose tolerance in vivo and improved glucose-stimulated insulin release in human islets in vitro. Our data suggest that impaired reverse cholesterol transport characterizes clinical and experimental DKD and negatively influences podocyte function. Treatment with CD is safe and effective in preserving podocyte function in vitro and in vivo and may improve the metabolic control of diabetes.
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November 2013