• Biomolecules & Therapeutics
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• 제17권1호
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• pp.25-31
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• 2009

Clusterin is a heterodimeric sulfated glycoprotein and plays a role in many different types of cancer as a cell survival factor and helps cancerous cells to evade stress-induced apoptosis. To investigate whether the regulation of clusterin expression is involved in the mechanism of anticancer agent, we studied the effect of tamoxifen on clusterin expression in human prostate cancer PC-3 cells. Treatment of PC-3 cells with tamoxifen reduced cellular proliferation. Western blot analyses showed that treatment with tamoxifen suppressed clusterin expression in a concentration-dependent manner. Transfection with clusterin siRNA plasmid showed that clusterin is required for PC-3 cell survival. We found that tamoxifen resulted in a rapid decrease in the phosphorylation of Akt on Ser473 leading to prevent kinase activity. Expression of myristoylated Akt prevented tamoxifen-mediated clusterin downregulation. Interestingly, MG132, a wellknown proteasome inhibitor also recovered clusterin expression suppressed by tamoxifen. These data indicate that clusterin expression may be regulated by activation of Akt and ubiquitin-proteasome pathway plays an important role in tamoxifen-mediated clusterin suppression.

• 생명과학회지
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• 제20권4호
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• pp.584-588
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• 2010

Clusterin은 Apolipoprotein J 등으로도 불리우기도 하는데 이 유전자의 발현이 동맥경화의 진행에 영향을 미치며[4], 관상동맥질환과 같은 혈관질환에도 중요한 역할을 하는 것으로 보고되어 있다[9,10,18] 최근 연구결과에 따르면, clusterin 유전자 다형성 중 10580 C>A, 10613 A>G이 아프리카인에게서 HDL-C의 serum level에 영향을 미치며, 이들 변이가 African-American에게서 Caucasian보다는 드물게 나타나지만, Hispanic에게서는 빈번하게 일어나는 것으로 보고되어 있다[11]. 또 다른 연구에서는 11개의 유전자 다형성을 조사한 결과 -4453G >T, 4183 A>G, 5608 C>T 는 상관관계가 없는 것으로 나타났으나, 6316 delT 유전자 다형성은 상관관계가 있는 것으로 보고되었다[8]. 본 연구에서는 관상동맥질환 환자군과 대조군을 각각 100명으로 하여 한국인에서 clusterin 유전자 다형성을 조사하였고, 특히 -4453 T>G에서 유의한 차이를 보였다. 이는 이전의 연구결과[8]와는 다소 차이가 있는데, Miwa 등의 결과에 따르면 일본인에게서는 6316 delT가 4183 A>G 다형성보다 동맥경화와 상관관계가 크다고 보고되었으나, 본 연구결과를 분석해보면 5608 C>T 는 상관관계가 없었으며, -4453 T>G 다형성만 상관관계를 가지는 것으로 나타났다. 이러한 차이를 보이는 원인은 정확하게 지적할 수는 없으나, 다형성이 미치는 영향력이 서로 다른 유전적 그리고 환경적인 요인의 차이에 의해서 일어나는 것으로 추정된다. 따라서 본 연구결과의 의의를 확인하기 위하여서는 대상 환자 수와 대조군을 늘리고 clusterin 유전자의 여러 다형성에 대한 추가적인 연구를 할 필요가 있을 것으로 판단된다.

• Journal of Microbiology and Biotechnology
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• 제14권6호
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• pp.1333-1337
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• 2004

Oxidants such as hydrogen peroxide are powerful inducers of cell damage, ageing, and apoptosis. Since clusterin, a 75-80 kDa mammalian glycoprotein, is frequently found to be inducible in apoptotic cells and tissues, this study inquired into whether this would be a protective mechanism against further cell death. The aim was to find out whether overexpression of clusterin could protect cells from oxidant­induced stress and apoptosis. To clarify this issue, we generated and analyzed stable cell lines expressing fusion proteins of a rat clusterin with an enhanced green fluorescent protein (EGFP). When treated with varying concentrations of hydrogen peroxides, clusterin transfectants indeed showed increased resistance to apoptosis and exhibited a much higher survival rate than mock-transfected cells. On the other hand, neither intracellular re-distribution nor local concentration of clusterin-EGFP was observed, which leaves the question open about its anti-apoptotic mechanism. In conclusion, the overexpression of clusterin provides a means for protecting cells against oxidative stress and subsequent cell death.

• Journal of Oral Medicine and Pain
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• 제22권2호
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• pp.341-358
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• 1997

Clusterin is a highly glycosylated protein composed of two disulfide linked subunits. Although its biolobical action is not clearly defined, clusterin seems to be involved not only in remodeling of damaged tissue, but also in production of halitosis, the present study was designated to elucidate the expression of clusterin in the salivary gland of diabetic rats. For this study, 24 Sprague-Dawley rats were used for the experiment and divided into 2groups: control and experimental. The experimental group was composed of 18 rats and the control goup was 6 rats. After nduction of diabetes by STZ injection, the animals were sacrificed at 1,3,5,7,10,14 days. The parotid and submamndibular glands were observed histologically and the transcriptional expression of clusterin in the glands by Northern blot. The finding were as follows : 1. In experimental group, the salivary glands were observed at day 3 and then a seven destructive pattern was found in the glands at day 5. Howere, regeneration of gland tissue occured at day 14. 2. In experimental goup, destructive change was examined in the septal connective tissue after 7 days, and gradually more serious. 3. In experimental group, clusterin was expressed in the submandibular glands after 5 days, but in parotid glands to a lesser extent after 10 days. These results suggest that clusterin seems to be closely associated with histologic changes in the mucous glands rather serous glands.

• Journal of Oral Medicine and Pain
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• 제22권2호
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• pp.395-408
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• 1997

Generally, the major causative factor of halitosis is thought to be a sulfated compounds. Clusterin, a sulfated glycoprotein-2(SGP-2), composed of two disulfide linked subunits. It is conceivable that clusterin might be one of candidated causing halitosis. We assume that clusterin found in the salivary glands under stress conditions might examine clusterin in the salivary glands under stress conditions. For this study, 24 rats were divided into 2 group : 1)18 rats of group I were bathed in cold water for 30 seconds twice a day 2) 6 rats of group II were selected as a control. The animals were sacrified at day 0,3,5,7,10, and 14 of the experiment and the submandibular glands and parotid glands were removed. RNAs were purified from the salivary glands and the transcription of clusterin in the glands was measured by Northern blot analysis. The specimens of the salivary glands were subjected to Hematoxillin-Eosin and PAS stainings and examined under the light microscope. The findings were as follows : 1. In group I, clusterin was expressed remarkably in the submandibular glands at day 5 but in the parotid glands remarkably at day 3 day slightly at day 7. 2. No significant histologic change was found in the salivary glands except that acini were slightly apart from each other under the cold stress condition.

• BMB Reports
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• 제57권3호
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• pp.149-154
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• 2024

The stomach has emerged as a crucial endocrine organ in the regulation of feeding since the discovery of ghrelin. Gut-derived hormones, such as ghrelin and cholecystokinin, can act through the vagus nerve. We previously reported the satiety effect of hypothalamic clusterin, but the impact of peripheral clusterin remains unknown. In this study, we administered clusterin intraperitoneally to mice and observed its ability to suppress fasting-driven food intake. Interestingly, we found its synergism with cholecystokinin and antagonism with ghrelin. These effects were accompanied by increased c-fos immunoreactivity in nucleus tractus solitarius, area postrema, and hypothalamic paraventricular nucleus. Notably, truncal vagotomy abolished this response. The stomach expressed clusterin at high levels among the organs, and gastric clusterin was detected in specific enteroendocrine cells and the submucosal plexus. Gastric clusterin expression decreased after fasting but recovered after 2 hours of refeeding. Furthermore, we confirmed that stomachspecific overexpression of clusterin reduced food intake after overnight fasting. These results suggest that gastric clusterin may function as a gut-derived peptide involved in the regulation of feeding through the gut-brain axis.

• Journal of Oral Medicine and Pain
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• 제23권4호
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• pp.309-326
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• 1998

In general, the major causative factor of halitosis is thought to be a sulfated compounds. Clusterin, a sulfated glycoprotein-2(SGP-2), is frequently found in diabetic conditions and cold stress conditions. The same result is werum glucose level to diabeteic and cold stress conditions that founded Clusterin. Therefore, this study was performed to examine Clusterin in the slivary glands under stress conditions before insulin injection I.M. Fourty rats were diveded into 3 groups ; 1) 10 rats of gorup I were selected as a control 2) 15 rats beloning to group II were bathed in cold water for 30 seconds twice a day 3) 15 rats in group III received cold stress and injected I.M. with insulin. The rats were sacrifeced at day 0, 3, 5, 7 and 10 of the experiment and the submandibular glands and parotid galnds were removed. RNAs were purified from the salivary of the salivary glands were subjected to Hematoxillin-Eosin stainings and examined under the light microscope. The obtained results were as follows : 1. With immunohistochemistric method, in normal control goup, Clusterin was moderately stained in the intercalated ductal cell of the submandibualr glands, mild stained in the striated ductal cell of the submandibular glands, heavily stained on the cytoplasm of the intercalated ductal cell in the mucous submandibular glands nad slightrly stained in the intercalated ductal cell of the paroted gland, expressed negativity in the acina cell. 2. With immunohistochemistric method, Clusterin slightly increased in the acina cell of the submandibular glands under stress condition at 3 days after experement, moderately stained at 5 days after experiment so revealed positive response. And hearily in the intercalated ductal cell and mildly lin the acina celluar eytoplasm of the parotid glands under stress condition at 3 days experiment. 3. With immunohistochemistric method, no remarkable differences are found between the normal control group and stress conditioned group that insulin administration was performed before. 4. In the stressor-giving group, Clusterin mRNA was porminently expressed in submandibular gland after 5 days after experiment, in parotid gland after 3 days after experiment, performed in immunoelectrophoresis method. 5. In the insulin-injected nad stressor-giving group, Clusterin mRNA was not observed in all experimental submandibular and parotid gland, performed in immunoelectrophoresis method.

• 대한의생명과학회지
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• 제14권1호
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• pp.55-58
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• 2008

Clusterin is an 80 kDa heterodimetric glycosylated protein and it plays diverse biological roles in various tissues and organs. Clusterin is reported to be associated with the pathogenesis of coronary artery disease and atherosclerosis. Therefore, we investigated the genotype for the A/G polymorphism at the position 4,183 of clusterin gene in Koreans and compared genotype of patients with control group. 100 patients (Male 63, Female 37), who previously underwent coronary artery stent due to ischemic heart disease and 100 controls (Male 36, Female 64) participated in this study. There was a significant association between 4,183 A/G polymorphism in clusterin gene and coronary artery disease (CAD). The present study shows that clusterin gene A/G polymorphism may be associated with the pathogenesis of CAD. Further studies with larger population may be needed for the development of diagnostic methods at genetic level such as DNA chip.

• Journal of Oral Medicine and Pain
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• 제31권1호
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• pp.79-89
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• 2006

구강 내에 발생되는 질환의 대부분이 타액의 영향을 받는다는 사실과 타액에 영향을 주는 전신적인 요소 중에서도 스트레스가 중요하다는 것은 이미 잘 알려져 있으나, 스트레스가 타액선에 미치는 영향에 관해서는 자율신경에 의한 거시적 반응에 대하여만 소개가 되었을 뿐 세포수준의 미시적 변화에 대하여는 별다른 언급이 없었다.. 이에 본 연구에서는 다양한 스트레스 조건하에서 백서의 악하선이 어떠한 변화를 보이는지를 clusterin 의 발현양상을 관찰함으로써 유추해보고자 하였다. 부여할 스트레스 조건을 급성 구속스트레스와 만성 저강도 스트레스의 두 가지로 정하고 7주된 Sprague-Dawley계 웅성백서 51마리를 사용하여 정해진 기간동안 급성 구속스트레스와 만성 저강도 비예측성 스트레스 (CUMS)를 가한 후 희생하여 악하선을 절취하고 역시 면역조직화학법과 웨스턴 면역점적법을 이용하여 악하선에서 clusterin발현의 시간에 따른 변화를 관찰하였으며, 그 결과는 다음과 같다: 1. 급성 구속스트레스 군에서, Clusterin 이 발현된 모든 선포의 합은 1시간 군을 제외한 모든 실험군 (9시간, 24시간, 72시간, 120시간, 그리고 168시간 군) 에서 대조군에 비하여 유의성 있게 감소하는 경향을 보였다 (p<0.001). 2. 만성저강도스트레스 군에서, 대조군에 대한 clusterin이 발현된 모든 선포의 합은, 2주군(p<0.01)에서 대조군에 비하여 유의하게 증가되는 모습을 보여주었고, 4주군(p<0.01)과 5주군(p<0.001)에서 대조군에 비하여 유의성 있게 감소하는 경향을 보였다. 3. 만성 저강도 스트레스 실험에서 4주째까지는 대조군과 실험군간의 당선호도 차이에 있어서 유의한 변화가 보이지 않았으나, 5주째에 유의성 있는 감소를 나타내었다(p<0.001). 4. 만성 저강도 스트레스 부여군은 5주째 대조군에 비하여 유의성 있는 체중변화(p<0.001)를 보여주었으나, 수분섭취량의 변화는 유의성 있는 상관관계를 보여주지 못하였다. 5. 면역점적검사를 시행한 결과, 구속스트레스 군에서는 clusterin의 발현이 시간에 따라 일정하게 감소하는 것으로 표현되었고, CUMS 군에서는 2주째까지는 증가하다가 3주 이후부터 실험 전기간에 걸쳐 감소하는 것으로 나타났으며 이는 당선호도 및 몸무게 변화의 양상의 변화와 크게 다르지 않았다. 따라서 위의 실험결과를 놓고 볼 때, 타액선 clusterin의 발현이 급성과 만성에 관계없이 스트레스 부여 후에 감소하였지만, 다른 문헌에서 제안된 것처럼 clusterin 의 고갈에 의한 세포자사적 변화는 관찰되지 않았다. 따라서 향후 보다 강화된 강도의 급성스트레스를 부여하는 방법과 더 장기적으로 진행된 연구를 통하여 고강도 스트레스에서 clusterin의 발현감소와 함께 세포의 변성이나 자사가 초래되는지, 저강도 스트레스의 경우 장기간 시간이 경과함에 따라 원래의 상태에 가깝게 회복되는지, 다른 열 충격 단백질이나 세포 사멸 시에 나타나는 단백질들을 동시에 확인하여 보는 것이 필요할 것으로 사료된다.

• Journal of Oral Medicine and Pain
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• 제37권2호
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• pp.81-91
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• 2012

타액이 대부분의 구강 내 질환에 영향을 주는 것으로 알려져 있다. 반대로, 여러 전신적 조건이 타액의 흐름에 영향을 줄 수 있으며 이는 구강 건조증을 야기할 수 있는데, 특히 사회심리적 스트레스는 타액의 부족과 구강 건조증의 병인으로 큰 역할을 할 수 있다. 많은 연구에서 자율신경계 반응에 의한 스트레스의 타액선에의 거시적 효과에 중점을 두어왔다. 본 연구에서는 구속 스트레스 조건 하에서 백서(Rat) 이하선에서 clusterin의 변화를 관찰하였다. 연구를 위해, 10마리의 백서를 이용, 3그룹으로 구분하였다. 1) 그룹 1: 대조군으로 rat 2마리 2) 그룹 2 : 실험대조군으로 2마리를 두어 2시간 동안 restraint cone을 사용하여 구속스트레스를 부여 3)그룹 3 : 실험군으로 6마리를 두어 매일 2시간씩 restraint cone을 사용하여 구속 스트레스를 부여 백서는 스트레스 부여 후 즉시(그룹 2) 희생하거나 24, 48, 72 시간 후 희생하여 이하선을 절취하였다. Western blotting과 면역조직화학검사를 시행하여 다음과 같은 결과를 얻었다. 1. 백서의 이하선에서 clusterin이 약간 증가하였고 구속 스트레스 부여 직후 타액선관에서 명확하게 관찰되었다. 2. 백서의 이하선에서 clusterin은 구속 24시간, 48시간 후에 매우 감소되었으며, 타액선관에서도 소량 관찰되었다. 3. 백서의 이하선에서 clusterin은 구속 72시간 후 현저하게 증가되었으며, 역시 타액선관에 밀집하여 증가되었다.