Transgenic potato expressing Aβ reduce Aβ burden in Alzheimer’s disease mouse model

Youm, Jung Won,Kim, Hee,Han, Jee Hye Lo,Jang, Chang Hwan,Ha, Hee Jin,Mook-Jung, Inhee,Jeon, Jae Heung,Choi, Cheol Yong,Kim, Young Ho,Kim, Hyun Soon,Joung, Hyouk Elsevier 2005 FEBS letters Vol.579 No.30

<P><B>Abstract</B></P><P>Beta amyloid (Aβ) is believed one of the major pathogens of Alzheimer’s disease (AD), and the reduction of Aβ is considered a primary therapeutic target. Immunization with Aβ can reduce Aβ burden and pathological features in transgenic AD model mice. Transgenic potato plants were made using genes encoding 5 tandem repeats of Aβ1–42 peptides with an ER retention signal. Amyloid precursor protein transgenic mice (Tg2576) fed with transgenic potato tubers with adjuvant showed a primary immune response and a partial reduction of Aβ burden in the brain. Thus, Aβ tandem repeats can be expressed in transgenic potato plants to form immunologically functional Aβ, and these potatoes has a potential to be used for the prevention and treatment of AD.</P>

Tomatidine-stimulated maturation of human embryonic stem cell-derived cardiomyocytes for modeling mitochondrial dysfunction

Kim Ye Seul,Yoon Jung Won,Kim Dasol,Choi Seunghak,Kim Hyoung Kyu,Youm Jae Boum,Han Jin,Heo Soon Chul,Hyun Sung-Ae,Seo Jung-Wook,Kim Deok-Ho,Kim Jae Ho 생화학분자생물학회 2022 Experimental and molecular medicine Vol.54 No.-

Human embryonic stem cell-derived cardiomyocytes (hESC-CMs) have been reported to exhibit immature embryonic or fetal cardiomyocyte-like phenotypes. To enhance the maturation of hESC-CMs, we identified a natural steroidal alkaloid, tomatidine, as a new substance that stimulates the maturation of hESC-CMs. Treatment of human embryonic stem cells with tomatidine during cardiomyocyte differentiation stimulated the expression of several cardiomyocyte-specific markers and increased the density of T-tubules. Furthermore, tomatidine treatment augmented the number and size of mitochondria and enhanced the formation of mitochondrial lamellar cristae. Tomatidine treatment stimulated mitochondrial functions, including mitochondrial membrane potential, oxidative phosphorylation, and ATP production, in hESC-CMs. Tomatidine-treated hESC-CMs were more sensitive to doxorubicin-induced cardiotoxicity than the control cells. In conclusion, the present study suggests that tomatidine promotes the differentiation of stem cells to adult cardiomyocytes by accelerating mitochondrial biogenesis and maturation and that tomatidine-treated mature hESC-CMs can be used for cardiotoxicity screening and cardiac disease modeling.

Rationally engineered surface properties of carbon nanofibers for the enhanced supercapacitive performance of binary metal oxide nanosheets

Kim, Ji Hoon,Kim, Chang Hyo,Yoon, Hyeonseok,Youm, Je Sung,Jung, Yong Chae,Bunker, Christopher E.,Kim, Yoong Ahm,Yang, Kap Seung The Royal Society of Chemistry 2015 Journal of Materials Chemistry A Vol.3 No.39

<▼1><P>Electrochemically active binary metal oxide nanosheets on the surface of electrically conductive and porous carbon nanofibers exhibited a high pseudo-capacitive performance.</P></▼1><▼2><P>The hybridization of an electrochemically active metal oxide with electrically conductive carbon nanofibers (CNFs) has been utilized as a solution to overcome the energy density limitation of carbon-based supercapacitors as well as the poor cyclic stability of metal oxides. Herein, we have demonstrated the growth of binary metal oxide nanosheets on the engineered surface of CNFs to fully exploit their electrochemical activity. Metal oxide nanosheets were observed to grow vertically from the surface of CNFs. The high structural toughness of the CNF–metal oxide composite under strong sonication indicated strong interfacial binding strength between the metal oxide and the CNFs. The rationally designed porous CNFs presented a high specific surface area and showed high capacity for adsorbing metal ions, where the active edge sites acted as anchoring sites for the nucleation of metal oxides, thereby leading to the formation of a well dispersed and thin layer structure of binary metal oxide nanosheets. Excellent electrochemical performance (<I>e.g.</I>, specific capacitance of 2894.70 F g<SUP>−1</SUP> and energy density of 403.28 W h kg<SUP>−1</SUP>) was observed for these binary metal oxide nanosheets, which can be attributed to the large increase in the accessible surface area of the electrochemically active metal oxide nanosheets due to their homogeneous distribution on porous CNFs, as well as the efficient charge transfer from the metal oxide to the CNFs facilitated the improvement in the performance.</P></▼2>

Chemopreventive effects of garlic and mugwort mixture extract on Helicobacter pylori-associated mouse gastric carcinogenesis

Youm, So-Young,Kim, Tae-Wang,Shin, Sang Kyung,Jeong, Heon Sang,Kang, Jong-Koo,Kim, Tae Myoung,Kim, Kil Ho,Ahn, Byeongwoo The Korean Society of Veterinary Science 2014 大韓獸醫學會誌 Vol.54 No.3

Garlic and mugwort have long been used in traditional medicine to prevent various diseases. Several in vitro studies have reported protective efficacies of garlic and mugwort in cases of gastric cancer. In the present study, we investigated the cancer preventive effects of garlic and mugwort mixture extract (GME) in a Helicobacter (H.) pylori-associated gastric carcinogenesis mouse model. To induce gastric cancer, C57BL/6 mice were treated with N-methyl-N-nitrosourea and H. pylori. Various concentrations of GME (0, 100, 500, and 1,000 ppm) were then fed to the mice for 38 weeks, after which the tumor tissues were examined for histopathology, mucin histochemistry and ${\beta}$-catenin. The incidence of gastric tumors was significantly lower in the highest dose GME-treated mice (46.7%) than control mice (85.7%) (p < 0.05). The multiplicity and size of tumors were also significantly reduced by GME feeding in a dose-dependent manner (p < 0.01). Furthermore, GME suppressed the H. pylori-associated chronic inflammation measured by histologic grading of H. pylori density, chronic gastritis, glandular atrophy and intestinal metaplasia in non-tumorous gastric mucosae. Our data suggest that GME suppresses gastric tumorigenesis via suppression of H. pylori-associated chronic inflammation.

Spinning of a submicron sphere by Airy beams

Kim, Kyoung-Youm,Kim, Saehwa OPTICAL SOCIETY OF AMERICA 2016 Optics letters Vol.41 No.1

<P>We show that by employing two incoherent counter-propagating Airy beams, we can manipulate a submicron sphere to spin around a transverse axis. We can control not only the spinning speed, but also the direction of the spinning axis by changing the polarization directions of Airy beams. (C) 2015 Optical Society of America</P>

Guiding Principle of Light Waves Through Metamaterial Layers

Kim, Kyoung-Youm,Jung, Jaehoon,Kim, Jungho IEEE 2010 IEEE photonics technology letters Vol.22 No.18

<P>We propose a general principle for the guiding of light waves through heterogeneous metamaterial layers: light waves have a tendency to increase their portion guided through the medium having a larger <TEX>$N^{2}$</TEX> value than the neighbors, where <TEX>$N^{2}$</TEX> is defined as the product of material permittivity and permeability values. Using this principle, we discuss qualitatively the characteristics of fundamental optical modes in several metamaterial waveguide structures.</P>

Protein Kinase C Activates ATP-sensitive Potassium Channels in Rabbit Ventricular Myocytes

Kim, Na-Ri,Youm, Jae-Boum,Joo, Hyun,Kim, Hyung-Kyu,Kim, Eui-Yong,Han, Jin The Korean Society of Pharmacology 2005 The Korean Journal of Physiology & Pharmacology Vol.9 No.4

Several signal transduction pathways have been implicated in ischemic preconditioning induced by the activation of ATP-sensitive $K^+$ $(K_{ATP})$ channels. We examined whether protein kinase C (PKC) modulated the activity of $K_{ATP}$ channels by recording $K_{ATP}$ channel currents in rabbit ventricular myocytes using patch-clamp technique and found that phorbol 12,13-didecanoate (PDD) enhanced pinacidil-induced $K_{ATP}$ channel activity in the cell-attached configuration; and this effect was prevented by bisindolylmaleimide (BIM). $K_{ATP}$ channel activity was not increased by $4{\alpha}-PDD$. In excised insideout patches, PKC stimulated $K_{ATP}$ channels in the presence of 1 mM ATP, and this effect was abolished in the presence of BIM. Heat-inactivated PKC had no effect on channel activity. PKC-induced activation of $K_{ATP}$ channels was reversed by PP2A, and this effect was not detected in the presence of okadaic acid. These results suggest that PKC activates $K_{ATP}$ channels in rabbit ventricular myocytes.

Effects of Freezing of Gait and Visual Information on the Static Postural Control Ability in Patients with Parkinson's Disease

Kim, Jung Yee,Son, Min Ji,Kim, You Kyung,Lee, Meoung Gon,Kim, Jin Hee,Youm, Chang Hong Korean Society of Sport Biomechanics 2016 한국운동역학회지 Vol.26 No.3

Objective: The purpose of this study was to analyze the effects of freezing of gait and visual information on the static postural control ability in patients with Parkinson's Disease (PD) during the bipedal stance with feet together. Method: This study included a total of 36 patients with PD; the freezer group included 17 PD patients (age: $69.3{\pm}6.2yrs$, height: $159.6{\pm}9.0cm$, weight: $63.4{\pm}9.78kg$) and the nonfreezer group included 19 PD patients (age: $71.4{\pm}5.6yrs$, height: $155.8{\pm}7.1cm$, weight: $57.7{\pm}8.6kg$). Static postural control ability was analyzed using variables of center of pressure (COP) and dividing by mediolateral, anteroposterior, and integration factors during a bipedal stance with the eyes open and closed. Results: Freezers and nonfreezers showed increases in anteroposterior velocity, mediolateral velocity, averaged velocity, and mediolateral 95% edge frequency when visual information was blocked. Additionally, freezers had greater anteroposterior range, 95% confidence ellipse area, and COP anteroposterior mean position than nonfreezers. Conclusion: Freezers and nonfreezers showed a reduction in static postural control ability when visual information was blocked. Additionally, the results of this study found a significant difference in static postural control ability between freezers and nonfreezers with PD. In particular, anteroposterior range, 95% confidence ellipse area, and COP anteroposterior mean position might be used to distinguish between freezers and nonfreezers with PD.

Modulation by Melatonin of the Cardiotoxic and Antitumor Activities of Adriamycin

Kim, Chunghui,Kim, Nari,Joo, Hyun,Youm, Jae Boum,Park, Won Sun,Cuong, Dang Van,Park, Young Shik,Kim, Euiyong,Min, Churl-Ki,Han, Jin Lippincott Williams Wilkins, Inc. 2005 Journal of cardiovascular pharmacology Vol.46 No.2

In this study, we investigated the effects of melatonin on adriamycin-induced cardiotoxicity both in vivo in rats and in vitro, and on the antitumor activities of adriamycin on MDA-231 and NCI breast cancer cells. Rats that received a single intraperitoneal injection of 25 mg/kg adriamycin showed a mortality rate of 86%, which was reduced to 20% by melatonin treatment (10 mg/kg, SC for 6 days). Melatonin attenuated adriamycin-induced body-weight loss, hemodynamic dysfunction, and the morphologic and biochemical alterations caused by adriamycin. Melatonin also reduced adriamycin-induced nuclear DNA fragmentation, as assessed by the comet assay. In addition, the antitumor activity of adriamycin could be maintained using lower doses of this drug in combination with melatonin. Melatonin treatment in the concentration range of 0.1-2.5 mM inhibited the growth of human breast cancer cells. In terms of oncolytic activity, the combination of adriamycin and melatonin improved the antitumor activity of adriamycin, as indicated by an increase in the number of long-term survivors as well as decreases in body-weight losses resulting from adriamycin treatment. These results indicate that melatonin not only protects against adriamycin-induced cardiotoxicity but also enhances its antitumor activity. This combination of melatonin and adriamycin represents a potentially useful regimen for the treatment of human neoplasms because it allows the use of lower doses of adriamycin, thereby avoiding the toxic side effects associated with this drug.

Analysis of Kinematics and Kinetics According to Skill Level and Sex in Double-under Jump Rope Technique

Kim, Dae Young,Jang, Kyeong Hui,Lee, Myeoung Gon,Son, Min Ji,Kim, You Kyung,Kim, Jin Hee,Youm, Chang Hong Korean Society of Sport Biomechanics 2017 한국운동역학회지 Vol.27 No.3

Objective: The purpose of this study was to perform a kinematic and kinetic analysis of double-under jump rope technique according to skill level and sex. Method: Participants comprised a skilled group of 16 (9 males, 7 females), and an unskilled group of 16 with 6 months or less of experience (9 males, 7 females). Five consecutive double-under successes were regarded as 1 trial, and all participants were asked to complete 3 successful trials. The data for these 3 trials were averaged and analyzed after collecting the stable third jump in each trial. The variables used in the analysis included phase duration, total duration, flight time, vertical toe height, stance width, vertical center of mass displacement, and right lower limb ankle, knee, and hip joint angles in the sagittal plane during all events. Results: The skilled group had a shorter phase and total duration and a shorter flight time than the unskilled group. The vertical center of mass displacement and ankle dorsiflexion angle were significantly smaller in the skilled group. The male group had a shorter phase duration than the female group. The vertical toe height was greater, the stance width was smaller, and the ankle and hip flexion angles were smaller in the male group. Conclusion: Variables that can be used to distinguish between skill levels are phase and total duration, flight time, vertical center of mass displacement, and ankle dorsiflexion angle. Differences between sexes in double-under jump rope technique may be related to lower limb flexion angle control.