• The Korean Journal of Physiology and Pharmacology
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• 제7권3호
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• pp.181-185
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• 2003

Whether there exists a sympathetic neural regulation on the aquaporin (AQP) channels in the kidney was examined. Male Sprague-Dawley rats were used. They were renal nerve denervated by stripping the nervous and connective tissues passing along the renal artery and vein, and painting these vessels with 10% phenol solution through a midline abdominal incision. Three days later, the expression of AQP1-4 proteins in the denervated kidneys was determined. The content of norepinephrine was found significantly decreased following the denervation. Accordingly, the expression of AQP2 proteins was markedly decreased. The expression of AQP3 and AQP4 was also slightly but significantly decreased, while that of AQP1 was not. Neither the basal nor the AVP-stimulated accumulation of cAMP was significantly affected in the denervated kidney. It is suggested that the sympathetic nervous system has a tonic stimulatory effect on AQP channels in the kidney.

• 한국발생생물학회:학술대회논문집
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• 한국발생생물학회 2003년도 제3회 국제심포지움 및 학술대회
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• pp.62-62
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• 2003

Aquaporin (AQP) family protein은 일종의 수분 전달 통로 역할을 하는 단백질로 AQP를 통한 수분의 조절은 삼투압을 통한 물의 이동과 함께 조직내 정상적인 수분의 상성 유지에 필수적이다. 현재까지 11종의 AQP이 신장·뇌·정소·안구 등에서 발현이 확인되었다. AQP9은 물 뿐 아니라 carbamide, polyol, purine, pyrimidine, urea, glycerol 등의 이동에 관여한다. 본 연구에서는 생쥐에서 출생 후 성체에 이르는 동안 정소 내 AQP9의 발현, Leydig cell의 분화에 따른 AQP9의 발현을 조사하였다. 1, 2, 4, 8주령의 정소로부터 semiquantitative RT-PCR 및 real time PCR 법으로 AQP9의 발현을 분석한 결과 1주령에서는 발현되지 않았고 2주령에서는 미량이 발현되기 시작하였고, 4주령에서는 성체의 1/2수준으로 발현량이 급격히 증가하였고 성체에서는 다량으로 발현됨이 확인되었다. Semiquantitative RT-PCR 법과 real time PCR법을 비교할 때 주령별 발현 양상은 유사하였으나 4주령과 성체에서는 두 시험법 사이에 양적인 차이가 있었다. 면역조직화학염색 결과 주로 Leydig cell에서 AQP9의 발현이 확인되었다. 성체의 정소 균질액의 Western blot 상에서 분자량 80, 55, 35 및 23 kDa의 항원이 검출되어 dimer, trimer 형태로 존재할 가능성과 당쇄 결합에 의한 단백질의 변형이 있는 것으로 추정된다. 미성숙 개체의 정소에서는 23 form이 확인되는 반면 성체에서는 35 kDa form이 주로 발현되므로 정소에서 발현되는 AQP9의 경우 Post-translation 수준에서 AQP9의 변형이 수반되는 것으로 사료되며 AQP9의 기능과의 연관성은 추후 연구되어야 할 것이다. Leydig cell은 fetal 및 adult type 2종의 세포가 정소발달 과정에 출현, 사멸, 분화하며 이들은 각기 정소발달, 성숙과 정자형성에 필요한 steroidogenesis에 관여한다. 정소 내 AQP9의 발현은 17beta HSD의 발현 양상과 같게 나타나므로 성적 성숙에 따른 정소 내 AQP9의 발현의 증가는 adult type Leydig cell의 분화와 관련된 것으로 추측된다. 성체의 정소로부터 분리한 Leydig cell-enriched culture에 hCG를 처리한 결과 배양체의 AQP9의 발현이 증가하므로 AQP9은 LH 수용체 하위 신호전달과정을 통해 Leydig cell의 steroidogenesis 또는 생성된 steroids의 분비에 요구되는 수분 및 중성용질의 이동에 관여하는 것으로 사료된다.

• The Korean Journal of Physiology and Pharmacology
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• 제23권2호
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• pp.113-120
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• 2019

Mannosylerythritol lipids (MELs) are glycolipids and have several pharmacological efficacies. MELs also show skin-moisturizing efficacy through a yet-unknown underlying mechanism. Aquaporin-3 (AQP3) is a membrane protein that contributes to the water homeostasis of the epidermis, and decreased AQP3 expression following ultraviolet (UV)-irradiation of the skin is associated with reduced skin moisture. No previous study has examined whether the skin-moisturizing effect of MELs might act through the modulation of AQP3 expression. Here, we report for the first time that MELs ameliorate the UVA-induced downregulation of AQP3 in cultured human epidermal keratinocytes (HaCaT keratinocytes). Our results revealed that UVA irradiation decreases AQP3 expression at the protein and messenger RNA (mRNA) levels, but that MEL treatment significantly ameliorated these effects. Our mitogen-activated protein kinase inhibitor analysis revealed that phosphorylation of c-Jun N-terminal kinase (JNK), but not extracellular signal-regulated kinase or p38, mediates UVA-induced AQP3 downregulation, and that MEL treatment significantly suppressed the UVA-induced phosphorylation of JNK. To explore a possible mechanism, we tested whether MELs could regulate the expression of peroxidase proliferator-activated receptor gamma ($PPAR-{\gamma}$), which acts as a potent transcription factor for AQP3 expression. Interestingly, UVA irradiation significantly inhibited the mRNA expression of $PPAR-{\gamma}$ in HaCaT keratinocytes, whereas a JNK inhibitor and MELs significantly rescued this effect. Taken together, these findings suggest that MELs ameliorate UVA-induced AQP3 downregulation in HaCaT keratinocytes by suppressing JNK activation to block the decrease of $PPAR-{\gamma}$. Collectively, our findings suggest that MELs can be used as a potential ingredient that modulates AQP3 expression to improve skin moisturization following UVA irradiation-induced damage.

• 대한의생명과학회지
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• 제24권2호
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• pp.116-124
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• 2018

Lysozyme is known as a key substance of the innate immunity and have antibacterial effect in the mucosal tissues, especially middle ear. Aquaporin (AQP) functions as water movement in the tissue and has been expected to be participated in the inflammatory responses. In the present study, we investigated to reveal association of lysozymes and AQPs in otitis media. The gene expression of lysozyme genes, homo sapiens lysozyme (hLYZ), homo sapiens lysozyme M (hLYZ M), and homo sapiens lysozyme G like-2 (hLYGH), and AQP genes (AQP 0 - AQP 12) were measured from postauricular skin, mastoid mucosa, inflamed mastoid mucosa, and middle ear mucosa. The hLYZ, hLYZ M and hLYGH gene were expressed in mastoid mucosa, inflamed mastoid mucosa, middle ear mucosa. Of AQP genes, all AQP gene except AQP 3 gene were expressed in the tissue of middle ear. Among them, AQP 4, AQP 8, AQP 9, AQP 10, AQP 11 and AQP 12 were highly expressed in the inflamed mastoid mucosa and normal mastoid mucosa (P<0.001). Interestingly, expression levels of AQP 4, AQP 9, and AQP 12 gene were significantly higher in the inflamed mastoid mucosa compared to normal middle ear mucosa (P<0.05). These results suggest that lysozyme and AQPs could be associated with inflammatory response in the middle ear.

• 동의생리병리학회지
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• 제16권1호
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• pp.72-77
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• 2002

The present study was examined the effects of Bojungchiseup-tang water extract on the renal expression of renal function regulatory proteins including aquaporin 2 (AQP 2), aquaporin 3 (AQP 3), Na, K-ATPase α1 subunit, endothelial nitric oxide synthase (ecNOS), and inducible nitric oxide synthase (iNOS) in rats. The renal expression of AQP 3 was attenuated in rats administered with Bojungchiseup-tang water extract without altered expression of AQP 2, while ecNOS was up-regualted. Oral administration of Bojungchiseup-tang water extract (40 ㎕/100 g) also attenuated the renal expression of Na, K-ATPase α1-subunit and iNOS protein. These results suggest that the diuretic and natriuretic effects of Bojungchiseup-tang maybe causely related with a decreased expression of AQP 3 and increased expression of ecNOS.

• Asian Pacific Journal of Cancer Prevention
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• 제16권9호
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• pp.3973-3976
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• 2015

Objectives: To explore the expression of aquaporin 1 ($AQP_1$) in bladder uroepithelium cell carcinoma (BUCC) and its relevance to recurrence. Materials and Methods: Tissue samples from 45 BUCC patients who underwent total cystectomy or transurethral resection of bladder tumor (TURBT) and from 40 patients with non-bladder cancers who underwent special detection or treatments were collected. The level of expression of $AQP_1$ in BUCC tissues and normal bladder tissues was assessed by immunohistochemistry so as to analyze the relevance to pathological patterns and time of recurrence in BUCC patients. Results: The expression levels of $AQP_1$ normal bladder tissues and BUCC tissues were $2.175{\pm}0.693$ and $3.689{\pm}0.701$, respectively, and the difference was significant (t=9.99, P<0.0001). Marked increase was noted with BUCC histological grade and pathological stage (P<0.01). Moreover, the expression of $AQP_1$ was evidently higher in cancerous tissues with lymph node metastasis than in those without (P<0.01). With short-term recurrence, the positive cell expression rate of $AQP_1$ was higher in primary tissues, which increased obviously after recurrence. Additionally, the recurrent time of BUCC was negatively associated with the positive cell expression rate of $AQP_1$ and the difference between the expression of $AQP_1$ before and after recurrence (r=-0.843, F=39.302, P=0.000; r=-0.829, F=35.191, P=0.000). Conclusions: $AQP_1$, which reflects the grade, stage, lymph node metastasis and recurrence of BUCC, has potential guiding significance in the diagnosis and treatment of bladder cancarcinoma.

• Asian Pacific Journal of Cancer Prevention
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• 제15권15호
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• pp.6391-6395
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• 2014

Overexpression of aquaporins (AQPs) has been reported in several human cancers. Epidermal growth factor receptor (EGFR)-extracellular signal-regulated kinases 1/2 (Erk1/2) are associated with tumorigenesis and cancer progression and may upregulate AQP expression. In this study, we demonstrated that EGF (epidermal growth factor) induces SiHa cells migration and AQP8 expression. Wound healing results showed that cell migration was increased by 2.79-1.50-fold at 24h and 48h after EGF treatment. AQP8 expression was significantly increased (3.33-fold) at 48h after EGF treatment in SiHa cells. An EGFR kinase inhibitor, PD153035, blocked EGF-induced AQP8 expression and cell migration and AQP8 expression was decreased from 1.59-fold (EGF-treated) to 0.43-fold (PD153035-treated) in SiHa. Furthermore, the MEK (MAPK (mitogen-activated protein kinase)/Erk (extracellular signal regulated kinase)/Erk inhibitor U0126 also inhibited EGF-induced AQP8 expression and cell migration. AQP8 expression was decreased from 1.21-fold (EGF-treated) to 0.43-fold (U0126-treated). Immunofluorescence microscopy further confirmed the results. Collectively, our findings show that EGF induces AQP8 expression and cell migration in human cervical cancer SiHa cells via the EGFR/Erk1/2 signal transduction pathway.

• Clinical and Experimental Reproductive Medicine
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• 제27권2호
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• pp.133-144
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• 2000

Objective: Several water channels (aquaporins; AQP) that belong to the MIP (major intrinsic protein) family have identified. In the selected tissues including red blood cells or renal tubules, water movements are abundant and/or physiologically important. Unexpectedly, a high water permeability of human and ram sperm has been reported. Recent studies showed that AQP7 and AQP8 are present in testes, so that the high water permeability of human sperm suggested to be mediated by AQPs. Method: To identify the identity of aquaporins expressed in testes, RT-PCR was performed using degenerative primers, which were designed to correspond to highly conserved sequences surrounding the Asn-Pro-Ala (NPA) motifs in the aquaporins. New expressed AQP series were reconfirmed by immunohistochemical study using rabbit polyclonal antibodies. Results: DNA sequencing of PCR products revealed that AQP2 and AQP3 mRNA as well as AQP7 and AQP8 are expressed in human and rat testes. In human and rat testes, AQP2 are expressed in spermatozoa, interstitial cells and myofibroblasts and AQP3 are expressed in myofibroblasts of semineferous tubules on immunocytochemical stain. Conclusion: These results indicate that multiple aquaporins are expressed in testes, and that they may have important roles in the spermatogenesis and the germ cell function of testis.

• 대한본초학회지
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• 제25권4호
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• pp.85-93
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• 2010

Objectives : This study aimed at evaluation of the effects of Gastrodiae Rhizoma on brain edema and aquaporin water channel expressions in the brain. Methods : Brain edema following intracerebral hemorrhage (ICH) was induced by the stereotaxic intrastriatal injection of bacterial collagenase type VII in Sprague-Dawley rats. Then ethanol extract of Gastrodiae rhizoma was treated once a day for 3 days. Brain edema % and water contents, and cell size of neurons in the cerebral cortex were examined. Immuno-histochemistry was processed for AQP4, AQP1, and AQP9 expressions in the brain sections and area % of immuno-labeling was analyzed with image analysis. Results : 1. Ethanol extract of Gastrodiae Rhizoma reduced brain edema of ICH induced rats significantly. 2. Ethanol extract of Gastrodiae Rhizoma reduced excessive brain tissue water contents of ICH induced rats significantly. 3. Ethanol extract of Gastrodiae Rhizoma reduced cellular edema of neurons in cerebral cortex of ICH induced rats significantly. 4. Ethanol extract of Gastrodiae Rhizoma reduced AQP4 immuno-positive area % in cerebral cortex and external capsule of ICH induced rat brain significantly. 5. Ethanol extract of Gastrodiae Rhizoma reduced AQP9 immuno-positive area % in glia limitans externa of ICH induced rat brain significantly. Conclusions : These results suggest that Gastrodiae Rhizoma reveals protective effects against brain edema and cytotoxic edema of neurons by means of down-regulation of AQP4 expression in the brain.

• 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.