Increased store-operated Ca2+ entry mediated by GNB5 and STIM1

Namju Kang,Jung Yun Kang,Soonhong Park,Dong Min Shin 대한약리학회 2018 The Korean Journal of Physiology & Pharmacology Vol.22 No.3

Recent human genetic studies have shown that Gβ5 is related to various clinical symptoms, such as sinus bradycardia, cognitive disability, and attention deficit hyperactivity disorder. Although the calcium signaling cascade is closely associated with a heterotrimeric G-protein, the function of Gβ5 in calcium signaling and its relevance to clinical symptoms remain unknown. In this study, we investigated the in vitro changes of store-operated calcium entry (SOCE) with exogenous expression of Gβ5. The cells expressing Gβ5 had enhanced SOCE after depletion of calcium ion inside the endoplasmic reticulum. Gβ5 also augmented Stim1- and Orai1-dependent SOCE. An ORAI1 loss-of-function mutant did not show inhibition of Gβ5-induced SOCE, and a STIM1-ERM truncation mutant showed no enhancement of SOCE. These results suggested a novel role of GNB5 and Stim1, and provided insight into the regulatory mechanism of SOCE.

Humanin suppresses receptor activator of nuclear factor-B ligand-induced osteoclast differentiation via AMP-activated protein kinase activation

Namju Kang,Ki Woo Kim,Dong Min Shin 대한약리학회 2019 The Korean Journal of Physiology & Pharmacology Vol.23 No.5

Humanin (HN) is a mitochondrial peptide that exhibits cytoprotective actions against various stresses and diseases. HN has been shown to induce the phosphorylation of AMP-activated protein kinase (AMPK), which is a negative regulator of receptor activator of nuclear factor-B ligand (RANKL). However, the role of HN in osteoclastogenesis or other skeletal disorders remains unknown. Here, we examined whether HN regulates osteoclastogenesis via AMPK activation using bone marrowderived macrophage (BMM) cultures. Our results show that HN inhibited RANKL-induced osteoclast formation and reduced the expression of genes involved in osteoclastogenesis, including nuclear factor of activated T-cells cytoplasmic 1, osteoclastassociated receptor, cathepsin K, and tartrate-resistant acid phosphatase. Moreover, HN increased the levels of phosphorylated AMPK protein; compound C, an AMPK inhibitor, recovered HN-induced osteoclast differentiation. In addition, we found that HN significantly decreased the levels of RANKL-induced reactive oxygen species in BMMs. Therefore, these results indicate that HN plays an important role in osteoclastogenesis and may function as an inhibitor of bone disorders via AMPK activation.

An Overview on the Characteristics of Calcium Chloro-aluminate Clinker

Namju Lee,Gwang Mok Kim,Hyeon Gyu Kim,Ji Whan Ahn 한국에너지학회 2018 한국에너지공학회 학술발표회 Vol.2018 No.04

A Literature Study on Reduction Factor of Cognitive Load as an Influencing Variable of Learning Effectiveness in Flipped Learning Environment

( Namju Oh ),( Insook Lee ) 한국교육공학회 2016 한국교육공학회 학술대회발표자료집 Vol.2016 No.1

Interest in flipped learning, an education model that proposes reverse performance of classroom lecture and assignment or homework, has been growing as per the direction of education policy which emphasizes creative and self-directed learning. The purposes of this study are as follows: What are the factors influencing reduction of cognitive load? What are the positive learning effectiveness factors found in main research on flipped learning? Which factors are influencing reduction of cognitive load as positive flipped learning effectiveness factors? In order to achieve these purposes, first of all, positive learning effectiveness shown in flipped learning environment has been surveyed. Then, the factors affecting on cognitive load reduction has been reviewed through literature analysis. Based on these results, we will research the inter-relationship between factors influencing on reduction of cognitive load and ones deducted from flipped learning effectiveness so as to deduct implications to execute teaching and learning strategies considering learners`` cognitive load reduction.

Comparison of hepatotoxicant-induced cytotoxicity assays in human induced-pluripotent stem cells (QIA7)

Namju Kim,Ji-Hyun Bang,Hee Yi,Hyun-Ok Ku,Moon Her,Byung-Suk Jeon 한국실험동물학회 2020 한국실험동물학회 학술발표대회 논문집 Vol.2020 No.7

Comparison of liver injury markers in 2D and 3D cell culture models: AST, ALT and LDH assays after hepatotoxicants treatment

NamJu Kim,Ji-Hyun Bang,Hee Yi,Moon Her,Hyun-Ok Ku,Byung-Suk Jeon 한국실험동물학회 2021 한국실험동물학회 학술발표대회 논문집 Vol.2021 No.7

In vitro cytotoxicity testing has become an integral aspect of drug-induced toxicity study because it is a convenient, cost-effective and predictive means of characterizing the toxic potential of drugs. The present study aimed to investigate the drug-induced cytotoxicity and effects of the liver enzymes such as ALT, AST and LDH enzyme activity in human cell. However, there are no reports of a comparison of ALT, AST, and LDH enzyme activity after hepatotoxicants treatment in 2D and 3D cell cultures. Therefore, the purpose of this study is to investigate the difference in expression of liver injury factors after treatment with hepatotoxicants in 2D and 3D culture models. Cell cytotoxicity and liver injury factors were confirmed by human induced-pluripotent stem cells. The expression of the liver injury factors were increasd, as results of the WST-1 and CellTiter decreased on concentration-dependently. In conclusion, the expression of liver injury factors were found to be higher in 2D cultures. However, it was confirmed that the reactivity was different depending on the cell death mechanism of the drugs.

A review of osteosarcopenic obesity related to nutritional intake and exercise

Namju Lee 한국응용과학기술학회 (구.한국유화학회) 2019 한국응용과학기술학회지 Vol.36 No.3

Recently, osteosarcopenic obesity (OSO) has been identified and notified world wide. Therefore, this study reviewed OSO related to lifestyle factors such as nutritional intake and exercise. Due to aging, OSO may be initiated by dietary factors and obesity related factors. Reduced muscle mass and increased fat mass may negatively impact bone health causing OSO. The complication of OSO development should be related to dietary imbalance combined with declined exercise and this may contribute to induce OSO by decreasing bone mass, muscle mass, and increasing obesity with aging. To prevent OSO, reaching peak bone mass and building optimal muscle and fat mass through exercise would be recommended. For treating OSO, balanced dietary intake and regular exercise through a whole life would be needed. In addition, sufficient carbohydrate and fat intake for minimizing protein catabolism would be recommended to prevent OSO. The combination of aerobic exercise and resistance training also would be an effective intervention for OSO population.

Hippotherapy and neurofeedback training effect on the brain function and serum brain-derived neurotrophic factor level changes in children with attention-deficit or/and hyperactivity disorder

( Namju Lee ),( Sok Park ),( Jongkyu Kim ) 한국운동영양학회 2017 Physical Activity and Nutrition (Phys Act Nutr) Vol.21 No.3

[Purpose] The purpose of this study was to investigate the effect of hippotherapy and electroencephalography (EEG) neurofeedback on brain function and blood brain-derived neurotrophic factor (BDNF) level in children with attention-deficit or/and hyperactivity disorder (ADHD). [Methods] Sixteen children with ADHD participated in this study and were randomly divided into 2 groups, a 1-time hippotherapy group (W1G, n = 8) and a 2-time hippotherapy group (W2G, n = 8). All the participants attended 8 weeks of hippotherapy program in the primary training, and then 7 children with ADHD attended 8 weeks of hippotherapy program combined with neurofeedback training in the secondary training. Blood BDNF levels were measured, and functional magnetic resonance imaging (fMRI) was performed. The EEG neurofeedback training program was used to train and measure psychological factors. [Results] The combined effect of hippotherapy and neurofeedback on BDNF level showed a decreased tendency in W1G (pretraining, 1766.03 ± 362.54 pg/ml; posttraining, 1630.65 ± 276.70 pg/ml). However, the BDNF level of W2G showed an increased tendency (pretraining, 1968.28 ± 429.08 pg/ml; posttraining, 1976.28 ± 425.35 pg/ml). Moreover, combined training showed a significant group x repetition interaction in W1G (pretraining, 1436.57 ± 368.76 pg/ml; posttraining, 1525.23 ± 346.22 pg/ml; F = 3.870, p = 0.039). fMRI results showed that the left thalamus activity in both groups had a decreased tendency and a significantly lower change in W2G than in W1G (p < 0.05). [Conclusion] This study confirmed a significant increase in blood BDNF level after combined training, which may induce brain function improvement in children with ADHD.

The Benefits of Exercise Effect on Cancer: A Review

( Namju Lee ) 한국운동생리학회(구 한국운동과학회) 2020 운동과학 Vol.29 No.1

PURPOSE: Exercise has been greatly shown to be effective on cancer patients and thus improves functional capacity in cancer patients and lowers a risk of cancer recurrence. The growing numbers of cancer population has been diagnosed and therefore, effect of exercise on cancer should be focused as a great intervention. Therefore, this study reviews the benefits of exercise on cancer and exercise guidelines for cancer population. METHODS: This study reviews 30 previous studies focusing on the benefits of exercise on various types of cancer such as breast, colon, colorectal, liver, lung, ovary, brain, prostate, and melanoma. RESULTS: Improvement in muscle strength, aerobic capacity, body balance throughout optimal exercise would be necessary for cancer patients and survivors for their life-long health by improving overall body function. To reach a healthy life, they need to conduct at least 150 minutes of moderate aerobic exercise or 75 minutes of vigorous aerobic exercise per week, and also at least 2 days per week of resistance exercise with moderate to high intensity for all major muscle groups. Exercise intervention needs to be safe during and after cancer treatments and results in improvements in physical functioning, cancer-related symptoms, and quality of life. Especially, patients and/or survivors with prostate cancer and melanoma are required to exercise with prescription because exercise may induce unexpected effects on health in those population. CONCLUSIONS: Implications for exercise affects related to cancer are still unknown; however, the benefits of exercise to physical functioning and quality of life are sufficient for cancer patients and survivors.

Effects of hippotherapy on brain function, BDNF level, and physical fitness in children with ADHD

( Namju Lee ),( Sok Park ),( Jongkyu Kim ) 한국운동영양학회 2015 Physical Activity and Nutrition (Phys Act Nutr) Vol.19 No.2

Purpose The purpose of this study was to examine the effects of hippotherapy on brain function and levels of blood-derived neurotrophic factor (BDNF) in children with attention deficit and/or hyperactivity disorder (ADHD). [Methods] The hippotherapy group (HRG) included twenty children with ADHD and the control group (CG) included 19 children. All participants’ physical fitness, fMRI brain scans, and blood BDNF levels were measured at baseline and after 32 weeks of participating in hippotherapy. [Results] After 32 weeks of participating in hippotherapy, the body fat of the HRG was significantly decreased (-1.12 ± 4.20%) and the body fat of the CG was increased (2.38 ± 6.35%) (p = 0.049). There was no significant difference of physical fitness in both groups (p > 0.05). Although there was a higher decrease in the activated insular area in the HRG (-1.59 ± 0.99) than in the CG (-1.14 ± 1.41), there was no significant difference between the two groups (p > 0.05) Also, there was a higher increase in the activated cerebellum area in the HRG (1.97 ± 1.45) than in the CG (1.92 ± 1.81). However, there was no significant difference between the two groups (p > 0.05). BDNF levels showed an increased tendency in the HRG (166.29 ± 277.52pg) compared to the CG (21.13 ± 686.33pg); otherwise, there was not any significant difference in these blood levels between the two groups (p > 0.05). It can be assumed that big individual differences in the level of ADHD in the study participants might not cause any significant results, although there might be positive changes in the brain function of children with ADHD. [Conclusion] Therefore, this study suggests that hippotherapy training would need to be modified and developed to increase the efficacy of hippotherapy in children with ADHD.