• 한국발생생물학회지:발생과생식
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• 제24권1호
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• pp.31-41
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• 2020

We investigated the effects of endoplasmic reticulum (ER) stress inhibitor and antioxidant treatments during the micromanipulation of somatic cell nuclear transfer (SCNT) on in vitro development of SCNT embryos. Tauroursodeoxycholic acid (TUDCA), an ER stress inhibitor and vitamin C (Vit. C), an antioxidant, were treated by alone or in combination, then, the level of X-box binding protein 1 (Xbp1) splicing and the expressions of ER stress-associated genes, oxidative stress-related genes, and apoptotic genes were confirmed in the 1-cell and blastocyst stages. In the 1-cell stage, the levels of Xbp1 splicing were significantly decreased in TUDCA and Vit. C treatment groups compared to the control (p<0.05). In addition, the expression levels of most ER stress-associated genes and oxidative stress-related genes were significantly lower in all treatment groups than the control (p<0.05), and the transcript levels of apoptotic genes were also significantly lower in all treatment groups than the control (p<0.05). In the blastocyst stage, decreased expression of ER stress-, oxidative stress-, and apoptosis-related genes were observed only in some treatments. However, the blastocyst formation rates in TUDCA and Vit. C treatment groups (24.8% and 22.0%, respectively) and mean blastocyst cell number in all treatment groups (59.7±4.3 to 63.5±3.3) were significantly higher (p<0.05) than those of control. The results showed that the TUDCA or Vit. C treatment during micromanipulation inhibited both ER and oxidative stresses in the early stage of SCNT embryos, thereby reducing cell damage and promoting in vitro development.

• Molecules and Cells
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• 제37권2호
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• pp.89-94
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• 2014

Fission and fusion of mitochondrial tubules are the main processes determining mitochondrial shape and size in cells. As more evidence is found for the involvement of mitochondrial morphology in human pathology, it is important to elucidate the mechanisms of mitochondrial fission and fusion. Mitochondrial morphology is highly sensitive to changing environmental conditions, indicating the involvement of cellular signaling pathways. In addition, the well-established structural connection between the endoplasmic reticulum (ER) and mitochondria has recently been found to play a role in mitochondrial fission. This minireview describes the latest advancements in understanding the regulatory mechanisms controlling mitochondrial morphology, as well as the ER-mediated structural maintenance of mitochondria, with a specific emphasis on mitochondrial fission.

• 한국발생생물학회지:발생과생식
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• 제22권1호
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• pp.73-83
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• 2018

This study investigates the endoplasmic reticulum (ER) stress and subsequent apoptosis in duced during somatic cell nuclear transfer (SCNT) process of porcine SCNT embryos. Porcine SCNT and in vitro fertilization (IVF) embryos were sampled at 3 h and 20 h after SCNT or IVF and at the blastocyst stage for mRNA extraction. The x-box binding protein 1 (Xbp1) mRNA and the expressions of ER stress-associated genes were confirmed by RT-PCR or RT-qPCR. Apoptotic gene expression was analyzed by RT-PCR. Before commencing SCNT, somatic cells treated with tunicamycin (TM), an ER stress inducer, confirmed the splicing of Xbp1 mRNA and increased expressions of ER stress-associated genes. In all the embryonic stages, the SCNT embryos, when compared with the IVF embryos, showed slightly increased expression of spliced Xbp1 (Xbp1s) mRNA and significantly increased expression of ER stress-associated genes (p<0.05). In all stages, apoptotic gene expression was slightly higher in the SCNT embryos, but not significantly different from that of the IVF embryos except for the Bax/Bcl2L1 ratio in the 1-cell stage (p<0.05). The result of this study indicates that excessive ER stress can be induced by the SCNT process, which induce apoptosis of SCNT embryos.

• IMMUNE NETWORK
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• 제12권5호
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• pp.189-195
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• 2012

It has been reported that vitamin C plays an effective role in the treatment and prevention of cancer, but its specific mechanisms are still largely unknown. The incidence of colon cancer is now increasing in Korea. Therefore, we have examined here the effect of vitamin C on the induction of the apoptosis on colon cancer and its related mechanisms. We have found that remarkable increase of the apoptosis and the calcium influx in endoplasmic reticulum (ER) in human colon cancer cell line, HCT-8. However, vitamin C-induced apoptosis was effectively inhibited by the pre-treatment of BAPTA-AM (1,2-bis(o-aminophenoxy) ethane-N,N,N',N'-tetraacetic acid), which is well-known as a calcium specific chelator. During the apoptosis, we found the increase of the translocation of Bad to mitochondria from cytosol, after releasing from 14-3-$3{\beta}$. In this process, the expression of Bax, a well-known pro-apoptotic protein, was also increased. Taken together, vitamin C induces apoptosis of colon cancer cell line, HCT-8 through the increase of 1) the calcium influx in endoplasmic reticulum (ER), 2) the translocation of Bad to mitochondria, and 3) the expression of Bax.

• 운동영양학회지
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• 제17권2호
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• pp.35-42
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• 2013

The purpose of this study was to identify the effects of gene expression of endoplasmic reticulum (ER) stress in skeletal muscle and adipose tissue on acute exhaustive exercise. Thirty-five Sparague Dawley male rats were divided into a control group (CON, n = 7) and a exhaustive exercise group (n = 28), immediately after exhaustive exercise group (n = 7), after 30 minutes exhaustive exercise group (n = 7), after 60 minutes exhaustive exercise group (n = 7), after 180 minutes exhaustive exercise group (n = 7). As a result, changes in the composition of the blood serum triglyceride concentration increased significantly in immediately after exhaustive exercise group, On the contrary, blood glucose showed a significantly decreased (p < .05). Homeostasis of energy metabolism due to exhaustive exercise as a result of the mechanism of action of skeletal muscle in the glycogenolysis and absorption, which indicates that the process of means. On the other hand, a result of examining changes in endoplasmic reticulum stress-related proteins in skeletal muscle and adipose tissue, JNK1 except in skeletal muscle BiP, ATF4, CHOP, GRP78 mRNA increased significantly immediately after exercise, and after 30 minutes returned to normal levels that could be confirmed (p < .05). BiP mRNA in adipose tissue show a similar pattern and skeletal muscle increased significantly immediately after exercise, but other changes in the specificity of the endoplasmic reticulum stress-related proteins also did not appear. In conclusion, Exercise applies and exercise training duration and exercise intensity as well as research on the interaction of the endoplasmic reticulum stress-related genes should be study continuously, to be more clear.

• Applied Microscopy
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• 제31권4호
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• pp.347-354
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• 2001

완두 종자 발달의 이른 시기에 특징적으로 조면 소포체 내강에 단백질이 축적되는데 이 단백질에 대한 전자현미경적 면역세포 화학적 반응을 실시한 결과 legumin으로 확인되었다. 이 단백질은 소포체 내강에 점점 축적되고 소포체 끝이 부풀어서 단백과립으로 발달하였다. 완두의 단백과립 발달 과정은 3가지 유형이 확인 되었는데, 단백질 저장 액포의 분절에 의해서 형성된 제 1형 단백과립, 가장자리에 단백질이 축적된 단백질 저장 액포의 budding에 의해서 형성된 제 2 형 단백과립, 그리고 단백질 저장 소포체의 끝이 부풀어서 형성된 제 3형 단백과립으로 구분되었다. 제 3형 단백과립은 수정 후 $23\sim25$일 사이의 짧은 기간에 급격하게 발달되어 자엽세포를 가득차게 만드는 것으로 확인 되었으며, 이러한 유형은 지금까지 알려지지 않은 새로운 단백과립 발달과정으로 생각된다.

• Applied Microscopy
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• 제32권2호
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• pp.149-156
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• 2002

본 연구는 흰쥐의 간장에서 납 독성에 대한 활성탄 효과를 연구하는데 그 목적이 있다. 실험동물은 $7{\sim}8$주된 150 g 내외의 Sparague-Dewley계 웅성 Rat를 사용하였다. lead acetate (500 ppm)를 1주 2회 복강 투여하였고 활성탄(40 mg/kg)을 1일/1회씩 경구투여하여 4주, 8주째에 간장을 적출해서 투과전자현미경으로 관찰한 바 다음과 같은 결과를 얻었다. 납 단독투여 4주군은 과립형질내세망의 수조가 팽대되고, 리보솜의 탈락이 관찰되었다. 핵은 약간 함입되어 불규칙하였으며 핵막은 팽대되어 내외막과 핵공이 불분명하게 나타났다. 납-활성탄 투여 4주군은 과립형질내세망은 리보솜이 부착된 정상적인형태로 관찰되었다. 다수의 리소좀이 관찰되었다. 핵은 둥근 형태로 관찰되었다. 납 단독투여 8주군은 과립형질내세망의 수조가 더욱 심하게 팽대되어 공포화를 나타냈다. 사립체는 더욱 팽창되서 사립체능이 절단, 손실되어 낮은 전자밀도를 나타냈다. 핵은 약간 함입되어 불규칙하고 핵막이 팽대되었다. 납-활성탄 투여 8주군은 일부 과립형질내세망의 수조가 팽대되었으나 리보솜이 부착된 정상적인 형태로 핵 주위에 전형적인 층판구조를 형성하였다. 사립체는 약간 팽창되었고, 핵은 정상으로 보였다.

• BMB Reports
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• 제42권11호
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• pp.719-724
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• 2009

Recent studies have revealed that endoplasmic reticulum (ER) disturbance is involved in the pathophysiology of neurodegenerative disorders, contributing to the activation of the ER stress-mediated apoptotic pathway. Therefore, we investigated here the molecular mechanisms underlying the ER-mitochondria axis, focusing on calcium as a potential mediator of cell death signals. Using NT2 cells treated with brefeldin A or tunicamycin, we observed that ER stress induces changes in the mitochondrial function, impairing mitochondrial membrane potential and distressing mitochondrial respiratory chain complex Moreover, stress stimuli at ER level evoked calcium fluxes between ER and mitochondria. Under these conditions, ER stress activated the unfolded protein response by an overexpression of GRP78, and also caspase-4 and-2, both involved upstream of caspase-9. Our findings show that ER and mitochondria interconnection plays a prominent role in the induction of neuronal cell death under particular stress circumstances.

• Biomolecules & Therapeutics
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• 제20권3호
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• pp.346-351
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• 2012

Cells show various stress signs when they are challenged with severe physiological problems. Majority of such cellular stresses are conveyed to endoplasmic reticulum (ER) and unfolded protein response (UPR) serves as typical defense mechanism against ER stress. This study investigated an interaction between ER stress agents using macropage cell line Raw 264.7. When activated by lipopolysaccharide (LPS), the cell lines showed typical indicators of ER stress. Along with molecular chaperones, the activation process leads to the production of additional inflammatory mediators. Following activation, the macrophage cell line was further treated with TUN and characterized in terms of chaperone expression and cytokine secretion. When treated with TUN, the activated macrophage cell leads to increased secretion of IL-6 although expression of ER stress markers, GRP94 and GRP78 increased. The secretion of cytokines continued until the addition of BFA which inhibits protein targeting from ER to Golgi. However, secretion of cytokines was ceased upon dual treatments with BFA and TG. This result strongly implies that cells may differently deal with various polypeptides depending on the urgency in cellular function under ER stress. Considering IL-6 is one of the most important signal molecules in macrophage, the molecule might be able to circumvent ER stress and UPR to reach its targeting site.

• 생명과학회지
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• 제27권2호
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• pp.233-240
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• 2017

본 연구는 소포체스트레스(endoplasmic reticulum stress)에 의해 유발되는 지방간(hepatic steatosis)에 대한 오미자추출물(Schisandra chinensis)의 주요성분인 gomisin A의 지방간 보호 효능에 대하여 연구하였다. 이를 위해 HepG2 세포에 소포체스트레스 유도물질인 tunicamycin 또는 palmitate을 처리하여 세포에서의 지방간 모델을 만들어 실험을 진행 하였으며, 소포체스트레스 표지자(marker)인 GRP78, CHOP, XBP-1의 발현을 측정하였다. Tunicamycin 처리한 세포에서는 GRP78, CHOP, XBP-1의 발현이 증가되었으나, gomisin A를 처리 한 세포에서는 이들의 발현 증가가 억제됨을 확인하였다. 이는 palmitate를 처리한 HepG2 세포에서도 palmitate에 의해 증가하는 소포체스트레스 표지자들이 gomisin A을 처리한 세포에서 발현이 감소함을 확인하였다. 이러한 결과에 의해, gomisin A는 소포체스트레스를 억제함을 알 수 있었다. 다음으로 gomisin A가 in vivo에서 소포체스트레스 및 지방간에 대한 보호효과가 있는지 확인하기 위해, tunicamycin과 고지방(high fat diet)으로 식이 한 쥐에서 소포체스트레스와 지방간의 보호효능에 대해 실험을 진행하였다. Tunicamycin과 고지방식이을 한 쥐의 간에서 중성지방이 증가하였으나, gomisin A를 처리한 쥐의 간에서 중성지방의 수준이 유의적으로 감소함을 확인하였다. 소포체스트레스 표지자들 역시 tunicamycin이나 고지방식이을 한 쥐에서 증가되나 gomisin A를 처리한 쥐에서 감소됨을 확인하였다. Gomisin A의 염증 반응에서의 조절기능을 확인하기 위하여 $TNF-{\alpha}$, IL-6 그리고 MCP1과 같은 염증관련 유전자들의 발현을 분석한 결과, tunicamycin이나 고지방식이을 한 쥐에서 염증유전자들의 발현이 증가하였으나 gomisin A를 처리한 쥐에서는 유의적으로 감소하였다. 종합적으로 본 연구 결과에 의하면, gomsin A는 소포체스트레스를 억제하여 지방간의 생성을 저해함을 알 수 있었다.