• Clinical and Experimental Reproductive Medicine
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• 제31권2호
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• pp.119-131
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• 2004

연구 목적: 난소에서 분비되는 스테로이드 호르몬인 에스트로젠과 프로게스테론은 포유동물의 생식기관 발달과 정상적인 생식 기능, 수정과 배아의 착상에 중요한 역할을 한다. 특히 에스트로젠은 자궁내액을 내강으로 분비하여 자궁부종 기작에 중요한 역할을 한다. 자궁내액은 정자의 수정능력 획득과 착상전 배아의 발달에 매우 중요하다. Aquaporin (AQP)은 막관통 물수송 단백질로서 여러 조직에 넓게 분포되어 있으며, 세포간 또는 상피세포간 물의 이동에 중요한 역할을 한다. 본 연구에서는 생쥐 자궁에서 스테로이드 호르몬에 의해 조절되는 자궁내액의 이동에 AQP 유전자가 관여하는지를 알아보았다. 연구 재료 및 방법: 난소 절제술을 시행한 생쥐에 스테로이드 호르몬을 피하주사하고 6, 12, 24시간 간격으로 자궁조직을 적출하였다. 대조군은 sesame oil만을 주사한 후 6시간째에 수획한 자궁조직을 사용하였으며, 실험군은 시간대별과 스테로이드 처리별로 채취한 자궁조직에서 역전사중합효소반응을 수행하였다. 역전사중합효소반응을 통해 막관통 단백질인 AQP-4, -5, -8 mRNA의 발현양상을 살펴보았다. 또한 mRNA의 위치를 살펴보기 위해 laser microdissection을 이용하여 RT-PCR을 수행하였다. 마지막으로 자궁조직내에서의 단백질 발현 부위를 관찰하기 위해 면역조직화학염색을 실시하였다. 결 과: AQP-4, -5, -8 mRNA은 프로게스테론을 처리한 군보다 에스트로젠을 처리한 군에서 많이 발현되었으며, 에스트로젠을 주사한 지 6시간째 발현정도를 대조군과 비교할 때 AQP-4, -5, -8 mRNA가 각각 7.9배, 2.8배, 3.8배로 나타났다. AQP-4, -5, -8 mRNA는 간충조직보다 자궁내 상피조직에서 스테로이드 호르몬의 영향을 받아 발현양상의 차이가 나타났으며, 주로 에스트로젠의 영향을 받아 발현이 증가하였다. AQP-4 단백질은 에스트로젠을 24시간 처리한 후 프로게스테론을 처리한 군의 자궁내 상피조직에서 많이 발현되었으며, AQP-5와 -8 단백질은 에스트로젠을 처리한 군의 자궁내 상피조직에서 발현이 증가하였다. 결 론: 이상의 결과를 통해 AQP-4, -5, -8은 주로 에스트로젠에 의해 자궁내 상피세포에서 발현이 증가되는 것으로 보아 에스트로젠의 영향하에 일어나는 자궁내액의 이동으로 인한 자궁부종기작에 이동통로로서 관여하는 것으로 사료된다.

• BMB Reports
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• 제45권2호
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• pp.96-101
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• 2012

Urea-based nitrogen fertilizer was widely utilized in maize production, but transporters involved in urea uptake, translocation and cellular homeostasis have not been identified. Here, we isolated three maize aquapoin genes, ZmNIP2;1, ZmNIP2;4 and ZmTIP4;4, from a cDNA library by heterogous complementation of a urea uptake-defective yeast. ZmNIP2;1 and ZmNIP2;4 belonged to the nodulin 26-like intrinsic proteins (NIPs) localized at plasma membrane, and ZmTIP4;4 belonged to the tonoplast intrinsic protein (TIPs) at vacuolar membrane. Quantitative RT-PCR revealed that ZmNIP2;1 was expressed constitutively in various organs while ZmNIP2;4 and ZmTIP4;4 transcripts were abundant in reproductive organs and roots. Expression of ZmTIP4;4 was significantly increased in roots and expanded leaves under nitrogen starvation, while those of ZmNIP2;1 and ZmNIP2;4 remained unaffected. Functions of maize aquapoin genes in urea transport together with their distinct expression manners suggested that they might play diverse roles on urea uptake and translocation, or equilibrating urea concentration across tonoplast.

• 생명과학회지
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• 제10권5호
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• pp.456-466
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• 2000

Aquaperin 4 (AQP4) is the mercurial water channel expressed abundantly in brain, especially the region related with cerebrospinal fluid reabsorption and osmoregulation. The primary structure of AQP4 water channel was elucidated but the molecular mechanism of AQP4 channel regulation is still unknown. To investigate the possible regulation of AQP4 water channel by phosphorylation via various protein kinases, osmotic water permeability of AQP4 expressed in Xenopus oocytes was measured by videomicroscopy technique. Forskolin (10 $\mu$M) did not affect osmotic water permeability of oocytes injected with AQP4 cRNA, excluding the regulation of AQP4 water cnannel by protein kinase A. Osmotic water permeability (P아래첨자) of AQP4-expressed oocytes was ingibited by the pretreatmeat of BAPTA/AM (up to 500$\mu$M), an intracellular Ca윗첨자 chelator, and calmidazolium (100$\mu$M), a specific Ca윗첨자/calmodulin antagonist, in a dose-dependent manner. The inhibition of osmotic water permeability (P아래첨자) by the calmidazolium treatment was completely reversed by the addition of calyculin A (0.1$\mu$M), a nonspecific phosphatase inhibitor. Phorbol 12-myristate 13-acetate (PMA), a protein kinase C activator, had biphasic effects on osmotic water permeability in AQP4 cRNA injected oocytes depending on its concentration; 21% increase by 100 nM PMA, 35% decrease by 1$\mu$M PMA. These effects were reversed with 2$\mu$M staurosporine, a nonspecific PKC inhibitor. These results suggest that phosphorylation of AQP4 water channel by Ca윗첨자/calmodulin kinase and protein kinase C might regulate the osmotic water permeability.

• The Korean Journal of Physiology and Pharmacology
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• 제1권5호
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• pp.495-504
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• 1997

Water transport is mediated by two distinct pathways, diffusional and channel-mediated water transport. The first molecular water channel was identified from human erythrocytes in 1992. Genetically-related proteins from other mammalian tissues have subsequently been identified to transport water, and the group is referred to as th "Aquaporins". Aquaporin-4 (AQP4) is most abundant in the brain, which may be involved in CSF reabsorption and osmoregulation. However, ontogeny and regulatory mechanisms of AQP4 channels have not been reported. Northern blot analysis showed that AQP4 mRNA began to be expressed in the brain just before birth and that its expression gradually increased by PN7 and then decreased at adult level. AQP4 was expressed predominantly in the ependymal cells of ventricles in newborn rats. And then its expression decreased in ependymal cells and increased gradually in other regions including supraoptic and paraventricular nuclei. AQP4 is also expressed in the subfornical organ, in which the expression level is not changed after birth. Cryogenic brain injury did not affect expression of AQP4 mRNA, while ischemic brain injury decreased it. Osmotic water permeability of AQP4 channel expressed in Xenopus oocytes was inhibited by the pretreatment of BAPTA/AM and calmidazolium, a $Ca^{2+}/Calmodulin$ kinase inhibitor, in a dose-dependent manner. These results indicate that the expression and the function of AQP4 channel are regulated by developmental processes and various pathophysiological conditions. These results will contribute to the understanding of fluid balance in the central nervous system and the osmoregulatory mechanisms of the body.

• Journal of Applied Biological Chemistry
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• 제51권3호
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• pp.102-110
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• 2008

Complementation assay of the urea uptake-defective yeast mutants led to the identification of the Arabidopsis AtTIP4;1 gene encoding the aquaporin. However, its physiological functions still remain elusive. In the present study, histochemical and genetic analyses were performed to understand the physiological roles of AtTIP4;1 in urea uptake. The AtTIP4;1 product was detectible in the roots, but not in the leaves, the stem, and the flower. Its promoter allowed the expression of the $\beta$-glucuronidase reporter gene in the roots and the apical meristem in Arabidopsis. The AtTIP4;1 products were induced under nitrogen-deficient conditions. To investigate the role of the tonoplast intrinsic protein in urea transport and developments, Arabidopsis with the loss- and the gain-of-function mutations by T-DNA insertion in AtTIP4;1 and 35S promoter-mediated overexpression of AtTIP4;1 were identified, respectively. The transfer DNA insertion and the AtTIP4;1-overexpressed plants showed normal growth and development under normal or abiotic stress growth conditions. The urea-uptake studies using $^{14}C$-labeled urea revealed higher accumulation of urea in the AtTIP4;1-overexpressed plants. These results provide evidence that overexpression of AtTIP4;1 leads to the increase in the urea-uptake rate in plants without detectable defects to the growth and development.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제32권1호
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• pp.1-7
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• 2006

The present study was aimed to explore the role of sympathetic and parasympathetic nerves in the regulation of sodium transporters and water channels in the salivary gland. Rats were denervated of their sympathetic and parasympathetic nerves to the submandibular gland, and the glandular expression of sodium transporters and water channels was determined by Western blot analysis. The expression of either ${\alpha}1$ or ${\beta}1$ subunit of Na, K-ATPase was not significantly affected either by the sympathetic or by the parasympathetic denervation. The expression of subunits of epithelial sodium channels was significantly increased both in the denervated and contralateral glands either by the sympathetic or by the parasympathetic denervation. Neither the sympathetic nor the parasympathetic denervation significantly altered the expression of aquaporin-1 (AQP1). Nor was the expression of AQP4 affected significantly by the parasympathetic or the sympathetic denervation. On the contrary, the expression of AQP5 was significantly increased not only by the parasympathetic but also by the sympathetic denervation. These results suggest that sympathetic and parasympathetic nerves have tonic regulatory effects on the regulation of certain sodium transporters and AQP water channels in the salivary gland.

• Molecules and Cells
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• 제39권4호
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• pp.292-298
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• 2016

Aquaporin 1 (AQP1) is expressed in most microvasculature endothelial cells and forms water channels that play major roles in a variety of physiologic processes. This study aimed to delineate the transcriptional regulation of AQP1 by Mef2c in endothelial cells. Mef2c cooperated with Sp1 to activate human AQP1 transcription by binding to its proximal promoter in human umbilical cord vein endothelial cells (HUVEC). Over-expression of Mef2c, Sp1, or Mef2c/Sp1 increased HUVEC migration and tube-forming ability, which can be abolished AQP1 knockdown. These data indicate that AQP1 is a direct target of Mef2c in regulating angiogenesis and vasculogenesis of endothelial cells.

• Journal of Acupuncture Research
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• 제22권1호
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• pp.61-75
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• 2005

동충하초(冬蟲夏草)가 신장(腎臟)기능에 미치는 영향을 실험적으로 규명하고자 부분 신절제술을 시행한 백서(白鼠)에 대하여 동충하초(冬蟲夏草) 경구투여(經口投與)와 신유(腎兪) 태계(太谿)에 약침(藥鍼)을 시행한 후 신장내(腎臟內) aquaporin -2 단백발현과 혈장내 renin, ANP, aldosterone 등의 혈액 학적 변화 및 뇨중 creatinine, Na, K Cl 를 관찰하여 다음과 같은 결과를 얻었다. 1. AQP2단백 발현은 경구투여(經口投與) 1, 3군, 약침(藥鍼) 1군에서 유의한 증가를 나타내었다. 2. 혈장 renin은 경구투여(經口投與) 1, 2, 3군, 약침(藥鍼) 1, 2, 3 군 모두에서 유의한 감소를 나타내었다. 3. 혈장 ANP는 경구투여(經口投與) 1군, 약침(藥鍼 ) 3군에서 유의한 증가를 나타내었다. 4. 혈장 aldosterone은 경구투여(經口投與) 2, 3군, 약침(藥鍼) 2군에서 유의한 감소를 나타내었다. 5. 혈청 triglyceride는 경구투여(經口投與) 2, 3군, 약침(藥鍼) 2, 3군에서 유의한 감소를 나타내었다. 6. 혈청 albumin은 경구투여(經口投與) 2군, 약침(藥鍼) 3군에서 유의한 증가를 나타내었다. 7. 혈청 total protein, BUN은 경구투여(經口投與) 1, 2, 3 군, 약침(藥鍼) 1, 2, 3군 모두에서 유의한 감소를 나타내었다. 8. 혈청 phosphorus는 경구투여(經口投與) 1, 2, 3군, 약침(藥鍼) 1, 2군에서 유의한 감소를 나타내었다. 9. 뇨(尿) creatinine은 경구투여(經口投與) 2군에서 유의한 증가를 나타내었고, 약침(藥鍼)군에서는 유의한 변화가 관찰되지 않았다. 10. 뇨(尿) Na는 경구투여(經口投與 ) 1, 2군, 약침(藥鍼) 1, 2, 3군에서 유의한 증가를 나타내었다. 11. 뇨 K는 경구투여(經口投與) 1, 3군에서 유의한 감소를 나타내었으나, 약침(藥鍼) 3군에서는 유의한 증가를 나타내었다. 12. 뇨 Cl는 경구투여(經口投與) 3군, 약침(藥鍼) 2, 3군에서 유의한 증가를 나타내었다.

• 대한생식의학회:학술대회논문집
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• 대한불임학회 2003년도 제45차 추계학술대회
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• pp.149-150
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• 2003

• 한국동물학회:학술대회논문집
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• 한국동물학회 2003년도 한국생물과학협회 학술발표대회
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• pp.167.4-167
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• 2003

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