• 항공우주의학회지
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• 제30권1호
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• pp.25-29
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• 2020

Space exploration is one of the dreams of humankind. However, the intriguing environment was a challenge for the human body, where we must counter with many extreme conditions such as thermal support, radiation, microgravity. Life, as well as the human body, developed and evolved in the continuous presence of gravity, especially when living creatures transfer from the ocean to the land. Once this gravitational force doesn't impact on the body, the drastic changes occur. Some of these changes were observed immediately, while others progress only slowly. Since the first orbital flight was performed, several hazards for the organs of the human body were identified [1]. These changes in human physiology can reverse when astronauts return to Earth. This article will review the published findings of the effects of microgravity exposure on the human body.

• 한국식물생명공학회:학술대회논문집
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• 한국식물생명공학회 2005년도 추계학술대회 및 한일 식물생명공학 심포지엄
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• pp.168-168
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• 2005

• 동의생리병리학회지
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• 제28권5호
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• pp.494-498
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• 2014

It is well known that Desomodii Herba (DH) has an effect to eliminate dampness, relieve jaundice and to clear away toxic material, relieve swelling in Korean Medicine. However, the effect of DH on breast cancer invasion is unknown. In this study, we investigated the inhibitory effect of DH extracts (DHE) on 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced matrix metalloproteinase-9 (MMP-9) expression and cell invasion, as well as the molecular mechanisms involved in MCF-7, human breast cancer cells. DHE inhibits TPA-induced MMP-9 protein and mRNA expressions in a dose-dependent fashion. DHE also inhibited the TPA-induced transcriptional activation of nuclear factor-kappa B (NF-${\kappa}B$). These results indicate that DHE-mediated inhibition of TPA-induced MMP-9 expression and cell invasion involves the suppression of NF-${\kappa}B$ pathway in MCF-7 cells.

• The Korean Journal of Physiology and Pharmacology
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• 제15권6호
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• pp.397-403
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• 2011

The proliferation, migration, cytokine release, and contraction of airway smooth muscle cells are key events in the airway remodeling process that occur in lung disease such as asthma, chronic obstruction pulmonary disease, and cancer. These events can be modulated by a number of factors, including cigarette smoke extract (CSE). CSE-induced alterations in the viability, migration, and contractile abilities of normal human airway cells remain unclear. This study investigated the effect of CSE on cell viability, migration, tumor necrosis factor (TNF)-${\alpha}$ secretion, and contraction in normal human bronchial smooth muscle cells (HBSMCs). Treatment of HBSMCs with 10% CSE induced cell death, and the death was accompanied by the generation of reactive oxygen species (ROS). CSE-induced cell death was reduced by N-acetyl-l-cysteine (NAC), an ROS scavenger. In addition, CSE reduced the migration ability of HBSMCs by 75%. The combination of NAC with CSE blocked the CSE-induced reduction of cell migration. However, CSE had no effect on TNF-${\alpha}$ secretion and NF-${\kappa}B$ activation. CSE induced an increase in intracellular $Ca^{2+}$ concentration in 64% of HBSMCs. CSE reduced the contractile ability of HBSMCs, and the ability was enhanced by NAC treatment. These results demonstrate that CSE treatment induces cell death and reduces migration and contraction by increasing ROS generation in normal HBSMCs. These results suggest that CSE may induce airway change through cell death and reduction in migration and contraction of normal HBSMCs.

• Nutritional Sciences
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• 제8권3호
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• pp.181-188
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• 2005

We investigated the effects of diet manipulation on pro- and macro-glycogen accumulation and mobilization during exercise in different kinds of muscle fiber and tissue. Thirty-two Sprague-Dawley rats were divided into groups representing one of two dietary conditions: high fat (HF, n=16) or standard chow (CHOW, n=16). Each dietary group was fm1her divided into control (REST, n=8) and exercise (EXE, n=8). After an eight-week dietary intervention period, the animals in EXE swam for 3 hours while the animals in REST remained at rest Skeletal muscle (soleus, red gastrocnemius and white gastrocnemius) and liver samples were then dissected out and used for analyses. 1here was no statistical difference in body weight between the animals in the HF and mow groups (p>.05). Three hours of exercise significantly increased plasma free fatty acid (FFA) concentration in the animals in the CHOW group but not in the animals in the HF group. Both citrate. synthase (CS) and $\beta$-hydroxyacyl dehydrogenase ($\beta$-HAD) activities in skeletal muscles were higher in the HF group than in the mow group. CS and $\beta$-HAD activities were also the highest in red gastrocnemius and the lowest in white gastrocnemius. At both time points (i.e., rest and immediately after exercise) intramuscular triglyceride (IMTG) and liver TG concentrations were significantly higher in the HF compared to the CHOW. IMTG and liver TG changed selectively in the CHOW. Except in white gastrocnemius muscle, there was no significant difference in total glycogen content between HF and mow at rest. Although exercise significantly lowered total glycogen content in all groups and tissues (p<.05), the degree of reduction was markedly greater in the mow than in the HF. Whereas changes in proglycogen concentration showed a trend similar to those of total glycogen, alterations in macroglycogen concentrations clearly differed from those of total glycogen. Specifically, the degree of reduction of macroglycogen following three hours of exercise was substantially greater in the CHOW than in the HF. These results suggest that metabolic alterations induced by a long-term high fat diet may be caused by macro-glycogen rather than pro-glycogen.

• Journal of Ginseng Research
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• 제33권1호
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• pp.26-32
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• 2009

인삼은 전통적으로 항당뇨 효과가 있는 것으로 보고되고 있다. Insulin-like growth factor (IGF)-I 역시 당뇨병성 신증의 발병 초기에 중요한 역할을 하는 것으로 알려져 있다. 이에 본 연구에서는 신장 근위세뇨관 세포에서 고포도당에 의한 IGF-I 분비에 대한 ginsenoside의 차단 효과 및 이와 관련된 신호전달계를 알아보았다. 결과는 다음과 같다. 고포도당에 의해 증가되었던 IGF-I분비 촉진 작용은 GTS, PD 및 PT 처리 시 차단되었으며, 세포 성장 작용 (세포 비대)에서도 같은 효과를 볼 수 있었다. 아울러 고포도당에 의한 cAMP 및 PKC 활성은 GTS 처리시 현저하게 차단되었으며 PD 및 PT 처리 시 역시 부분적으로 억제되는 것으로 나타났다. 이상의 결과를 볼 때 신장 근위세뇨관 세포에서 ginsenoside는 cAMP 및 PKC 활성 경로를 억제하여 고포도당에 의한 IGFs 분비 작용을 차단하는 것으로 나타났다.

• Reproductive and Developmental Biology
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• 제32권2호
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• pp.135-140
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• 2008

Recent studies on nuclear transfer and induced pluripotent stem cells have demonstrated that differentiated somatic cells can be returned to the undifferentiated state by reversing their developmental process. These epigenetically reprogrammed somatic cells may again be differentiated into various cell types, and used for cell replacement therapies through autologous transplantation to treat many degenerative diseases. To date, however, reprogramming of somatic cells into undifferentiated cells has been extremely inefficient. Hence, reliable markers to identify the event of reprogramming would assist effective selection of reprogrammed cells. In this study, a transgene construct encoding enhanced green fluorescent protein (EGFP) under the regulation of human Oct4 promoter was developed as a reporter for the reprogramming of somatic cells. Microinjection of the transgene construct into pronuclei of fertilized mouse eggs resulted in the emission of green fluorescence, suggesting that the undifferentiated cytoplasmic environment provided by fertilized eggs induces the expression of EGFP. Next, the transgene construct was introduced into human embryonic fibroblasts, and the nuclei from these cells were transferred into enucleated porcine oocytes. Along with their in vitro development, nuclear transfer embryos emitted green fluorescence, suggesting the reprogramming of donor nuclei in nuclear transfer embryos. The results of the present study demonstrate that expression of the transgene under the regulation of human Oct4 promoter coincides with epigenetic reprogramming, and may be used as a convenient marker that non-invasively reflects reprogramming of somatic cells.

• Molecules and Cells
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• 제41권2호
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• pp.110-118
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• 2018

The objective of this study was to induce the production of isthmic organizer (IsO)-like cells capable of secreting fibroblast growth factor (FGF) 8 and WNT1 from human embryonic stem cells (ESCs). The precise modulation of canonical Wnt signaling was achieved in the presence of the small molecule CHIR99021 ($0.6{\mu}M$) during the neural induction of human ESCs, resulting in the differentiation of these cells into IsO-like cells having a midbrain-hindbrain border (MHB) fate in a manner that recapitulated their developmental course in vivo. Resultant cells showed upregulated expression levels of FGF8 and WNT1. The addition of exogenous FGF8 further increased WNT1 expression by 2.6 fold. Gene ontology following microarray analysis confirmed that IsO-like cells enriched the expression of MHB-related genes by 40 fold compared to control cells. Lysates and conditioned media of IsO-like cells contained functional FGF8 and WNT1 proteins that could induce MHB-related genes in differentiating ESCs. The method for generating functional IsO-like cells described in this study could be used to study human central nervous system development and congenital malformations of the midbrain and hindbrain.

• 동의생리병리학회지
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• 제18권5호
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• pp.1382-1386
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• 2004

This study was performed for the investigation of vasodilatory efficacy and its underlying mechanisms of Samhwangsasim-tang(SST), herbal remedy. SST relaxed vascular strips precontracted with phenylephrine or KCI(51 mM), but the magnitude of relaxation was greater in phenylephrine(PE) induced contraction. The relaxation effects of SST was endothelium-independent. L-NAME, iNOS inhibitor, and methyl en blue(MB), cGMP inhibitor, did not attenuate the relaxation responses of SST. In the absence of extracellular Ca2+, pre-incubation of the aortic rings with SST significantly reduced the contraction by PE, suggesting that the relaxant action of the SST includes inhibition of Ca/sup 2+/ influx and release of Ca/sup 2+/ from intracellular stores (SR). In addition, the cell death was induced by SST in human aortic smooth muscle cells but not that of human umbilical vein endothelial cells. We conclude that in rat thoracic aorta, SST may induce in part vasodilation through inhibition of Ca/sup 2+/ influx and release of Ca/sup 2+/ from intracellular stores.

• Biomolecules & Therapeutics
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• 제25권4호
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• pp.354-361
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• 2017

Transcriptional co-activator with a PDZ-binding motif (TAZ) is an important factor in lysophosphatidic acid (LPA)-induced promotion of migration and proliferation of human mesenchymal stem cells (MSCs). The expression of TAZ significantly increased at 6 h after LPA treatment, and TAZ knockdown inhibited the LPA-induced migration and proliferation of MSCs. In addition, embryonic fibroblasts from TAZ knockout mice exhibited the reduction in LPA-induced migration and proliferation. The LPA1 receptor inhibitor Ki16425 blocked LPA responses in MSCs. Although TAZ knockdown or knockout did not reduce LPA-induced phosphorylation of ERK and AKT, the MEK inhibitor U0126 or the ROCK inhibitor Y27632 blocked LPA-induced TAZ expression along with the reduction in the proliferation and migration of MSCs. Our data suggest that TAZ is an important mediator of LPA signaling in MSCs in the downstream of MEK and ROCK signaling.