STATIN類降血脂藥物對血管平滑肌細胞之作用
動脈硬化是個致病率和致死率相當高的慢性發炎疾病，為台灣十大死因之一。在病理過程中血中濃度過高的膽固醇為動脈硬化的一大危險因子，其會誘發一連串的發炎反應驅使血管壁內皮細胞功能喪失，血壓上升，平滑肌細胞增生等。Statin 是臨床上十分有效的降血脂藥物，雖然其作用機制已知在於抑制膽固醇合成酵素 HMG-CoA reductase 而有降血脂功效，但近年來探討 statin 在抗發炎方面的作用也漸受重視。nitric oxide synthase (NOS) 代謝產物如 nitric oxide (NO)，cyclooxygenase (COX) 代謝產物如 prostaglandin (PGE?、PGI?)，及 heme oxygenase-1 (HO-1) 代謝產物如 carbon monoxide (CO)，均有文獻指出可以改善血流，而可能在動脈硬化上扮演保護角色。相反的，matrix metalloproteinase (MMP) 的表現會誘使更多的免疫細胞浸潤到血管壁，並增加動脈硬化斑破裂，引起栓塞和中風的發生。在此實驗中，我們利用培養的大鼠主動脈血管平滑肌細胞作為研究材料，發現了 statin (lovastatin 、pravastatin、atorvastatin 、fluvastatin) 具有一些和降血脂無關的直接保護血管壁能力。包括會增加 interleukin-1β (IL-1β) 所誘導 iNOS 蛋白的表現及NO 的產生; statin 本身會增加 COX-2 和 HO-1 蛋白的表現及 PGE? 和PGI? 的產生，及抑制 MMP-2 和 MMP-9 蛋白活性的表現。此外分析調控 iNOS 基因轉錄最為關鍵的基因轉錄因子 NF-κB，發現適量的 statin 會增加 IL-1β 活化NF-κB 的作用。值得一提的是雖然適量 NO 有維持血管恆定的功能，過量時則會造成血壓過低休克的現象，這就是細菌感染後因內毒素 lipopolysaccharide (LPS) 作用引發敗血性休克的主要原因之一。為更進一步釐清 statin 是否會影響受細菌感染病人的生命危險，我們也探討 statin 對LPS 作用的影響。結果發現 statin 反而會抑制 LPS 誘導大量 iNOS 蛋白的表現，NO 的產生及 NF-κB 的活化。這些新的實驗結果提供更多證據支持 statin 可以藉由維持血管舒張，減緩血管壁的發炎反應，穩定動脈硬化斑的作用，以有效控制動脈硬化各個病程的進展。這發現能讓我們更透徹明白 statin 的作用，且對將來研發 statin 在心血管疾病方面新的臨床治療用途是有所助益的。 ;The 3-hydroxy-3-methylglutaryl (HMG)-CoA reductase inhibitors, statins, are potent inhibitors of cholesterol synthesis and have wide therapeutic use in cardiovascular diseases. Recent evidence, however, suggests that the beneficial effects of statins may extend beyond their action on serum cholesterol levels. In this study, we investigated the effects of lovastatin, pravastatin, atorvastatin, and fluvastatin on cultured rat vascular smooth muscle cells. We found statins can inhibit LPS-induced iNOS expression and NO production, while they can potentiate IL-1β-elicited responses. Moreover, statins themselves can stimulate COX-2 expression, PGE?, PGI? formation, and HO-1 induction. In contrast, statins can inhibit basal and IL-1β-induced enzyme activities of MMP-9 and MMP-2. In studying the activity of NF-κB, which plays an important role for iNOS gene induction, we found that statin can increase IL-1β-induced NF-κB activity, while inhibit that induced by LPS. All these results suggest that stimulation of iNOS expression in the presence of IL-1β, togeth1er with the increased COX-2 and HO-1 expression might contribute to the beneficial effects of statins in atherosclerotic process in terms of vasodilation and inhibition of smooth muscle cell proliferation. The inhibition of MMP activity might enhance plaque stability and reduce the development of atherosclerosis. All these results strengthen the pleiotropic actions of statins in anti-inflammation and anti-atherosclerosis.
台灣兒科病人罹患神經母細胞瘤者可檢測到微小病毒B19的存在
罹患神經母細胞瘤的兒科病人，尤其是罹患stage IVs 神經母細胞瘤者，他們有些伴隨著非常嚴重的貧血，但卻檢測不出神經母細胞瘤已經侵犯骨髓；有時病情來勢洶洶，尤其是腫瘤細胞中已可偵測到N-myc 基因增幅者，診斷時腫瘤細胞可能已在腹腔四處擴散並已侵犯大部分的肝臟。但是，某些這種病患，特別是腫瘤細胞中N-myc 基因沒增幅者，即使在沒有治療的狀況下卻可能有自然恢復的現象，也就是腫瘤細胞會自動消退，但原因仍待進一步的證實與探討。可是，這些病人在其病情最嚴重的時候，骨髓內紅血球母細胞形態上的改變顯示可能與病毒感染有關。但是關於病毒來源的研究，現有的資訊仍然十分有限，其中最重要的是，病毒感染與引發其後天之免疫作用是否有關，更需要深層的研究。因此，為更進一步了解罹患神經母細胞瘤之兒科病人的病毒感染及病毒蛋白表現的作用，我們這次研究的目的在檢驗罹患神經母細胞瘤及貧血之兒科病人與微小病毒B19 (PVB19)、Epstein-Barr Virus (EBV)、腸病毒71 型(EV 71)和巨細胞病毒(CMV)的關係，以及病毒蛋白表現對這些病人的作用與臨床意義。In pediatric patients with neuroblastoma, in particular, those with stage IVs neuroblastoma, sometimes the disease was combined with severe anemia. However, no tumor involvement was detected in the bone marrow. Although some of these patients may have N-myc gene amplification, and the disease could have invaded many abdominal organs, especially liver, interestingly, the disease might regress spontaneously in some of these patients. The medical reason of the spontaneous regression, nonetheless, remains to be determined. It is worth noting that morphological changes of erythroid progenitor cells in the bone marrow have suggested virus infection in these pediatric patients. However, the available information of viral origin is limited. Furthermore, it is possible that the virus infection in these patients could be associated with the revocation of immune responses related to the spontaneous regression of the tumor. In this study we will investigate the relationship of parvovirus B19 (PVB19), Epstein-Barr virus (EBV), enterovirus 71 (EV71) and cytomegalovirus (CMV) with neuroblastoma by PCR in Taiwanese pediatric patients. Moreover, we will study the effect and the clinical significance of viral gene expression as well as N-myc gene amplification in these patients.
The Interplay of Iron and α-synuclein in mediating Neuroinflammation in Parkinson’s Disease
Neuroinflammation is implicated as a contributive factor to neurodegeneration in Parkinson’s disease (PD). Increased iron accumulation and deposition of -synuclein within Lewy Bodies in PD brains have been observed. It has been hypothesized that unbound iron is able to react with H2O2 to generate free radicals. Using the Divalent Metal Transporter-1 (DMT1) as a vehicle to transport iron into the brain, a DMT1 transgenic mouse model (DTg) was generated to recapitulate iron deposition in PD. The DTg was crossbred with the SNCA (synuclein) transgenic mouse to produce a DMT1_SNCA (BTg) mouse model to study the link between iron, -synuclein and neuroinflammation in PD. Our hypothesis predicts that iron exacerbates -synuclein toxicity by inducing larger inflammatory responses and consequently compromising functions of biomolecules. Our study shows that –synuclein triggers a low-grade inflammatory response by microglia and astrocytes while iron exacerbates -synuclein toxicity by eliciting immunological responses mediated by glia cells in the brain observed both in the DTg and BTg mice. Elevated levels of nitrated proteins were observed in the DTg, suggesting the role of iron in inducing nitrosative stress via upregulation of iNOS in glia cells. With the BTg mice, we hope to understand the effect of iron accumulation as an environmental stressor in aggravating -synuclein toxicity which may lead to the selective demise of dopaminergic neurons.
上樑不正下樑歪-脊椎側彎的探討
台灣大多數學校並無全面性脊椎側彎篩檢與追蹤的健康服務，因此學生脊椎側彎的問題都不易被發現。本研究的目的希望藉由長期的追蹤與鼓勵學生進行治療，以降低脊椎側彎的盛行率與側彎角度。台灣地區學齡兒童脊椎側彎的盛行率大約是3-3.5％，而本校脊椎側彎的盛行率大約在1％左右，而且女生明顯多於男生。根據篩檢發現本校脊椎側彎較易發生在BMI（Body Mass Index）值較低的學童身上，也就是說，瘦型體格罹患脊椎側彎的機會較高。脊椎側彎可以藉由簡單的目測及儀器測量實施篩檢，並配合醫師復健運動，可達預防與治療之效果。本校實施兩年即約有60%的成效。因此建議將脊椎側彎納入學校健康檢查的項目之一（包含國小五、六年級與國中階段）。 ;The scoliosis of school children cannot be discovered easily because the overall scoliosis screening and tracing are not provided in most schools in Taiwan. The main purpose of this study is to reduce the prevalence rate and the angle of scoliosis by proceeding scoliosis screening continuously, and encouraging the patients to take physical treatment at the same time. Compared with the scoliosis prevalence rate in Taiwan(3-3.5%), the rate in our school is about 1%. Furthermore, the girls with scoliosis are outnumber the boys with the disease. This study shows children with low BMI value will have higher probability to acquire scoliosis. In other words, thin children may fall victims of the disease more often. The scoliosis can be examined with some easy methods, such as unaided-eyes measuring or scoliosis detecting. Besides screening, hospital treatment can attain the effects of prevention and cure. For the first two years, the practice of scoliosis screening in our school can improve the disease obviously (about 60%). In conclusion, the study strongly suggests the scoliosis screening can be included into an item of health examination from the fifth graders to the ninth.
長期服用安非他命對小鼠腦部紋狀體內蛋白質表
安非他命的濫用在台灣是非常嚴重的公眾健康及社會問題。安非他命會導致一連串的行為異常，包括在中腦紋狀體內釋放多巴胺及阻止多巴胺回收來增加使用者的活動力。由於安非他命會對腦細胞造成傷害，本研究的目的為探討低劑量、無立即毒性之安非他命(類似於人類使用習慣)長期施打下，是否會對C57BL6 小鼠大腦紋狀體內的蛋白質表現有影響。因此利用西方點墨法分析施打低劑量安非他命(2 到6 mg/kg) 約一星期之後，C57BL6 小鼠的大腦紋狀體中一些重要蛋白質(包括腺.酸受體A2A-R、第五亞型腺.酸環化.AC5、caspase-8 及PARP) 的表現是否有改變。實驗結果顯示，低劑量安非他命處理對這些蛋白質的表現並沒有明顯的差異。但利用二維電泳法可看到有少許蛋白質，在經過安非他命處理下有顯著的差別，如KIAA0193 homolog 、GOS-28、gammacrystallin A、malate dehydrogenase 和phosphoglycerate mutase isozyme B (PGAM-B)。這些蛋白質中，malate dehydrogenase 和PGAM-B 與代謝和產生ATP 有關，但前者是增加的，而後者減少，推測安非他命會影響神經細胞的能量代謝，因此長期施打安非他命對紋狀體造成的影響值得進一步探討。;The wide spreading use of amphetamine (AMPH) in Taiwan has become a serious public health and social problem. AMPH evokes a series of behavior abnormality including enhanced locomotor behavior by releasing dopamine and inhibiting dopamine-uptake in the striatum. Since AMPH is known to cause brain damage, the purpose of this study is to investigate the expression of several important proteins in the striatum of C57BL6 mice after chronic treatment with low and non-toxic dosages of AMPH (mimicking the common usage pattern of AMPH addict). C57BL6 mice were daily IP-injected with various dosages of AMPH (0 to 6 mg/kg) for one week. Expression levels of A2A adenosine receptor (A2A-R), adenylyl cyclase type V (AC5), caspase-8 and PARP in the striatum were analyzed by Western blotting analysis. Most proteins examined were not affected by this 1-week AMPH treatment. By the aid of two-dimensional gel electrophoresis, expressions of a few striatal proteins (such as KIAA0193 homolog, GOS-28, gammacrystallin A, malate dehydrogenase and phosphoglycerate mutase isozyme B (PGAM-B) in AMPH-treated mice were altered. Note that malate dehydrogenase and PGAM-B are two enzymes involved in energy metabolism and ATP generation. Interestingly, the former was increased and while the latter was decreased in AMPH-treated mice. Collectively AMPH may affect the energy metabolism in neuronal cells. These results suggest that the injury induced by long-term AMPH exposure warrants our further concerns and investigation.
長期處理兒茶素對無機砷與氯化鎘之遺傳毒性
重金屬對人體傷害的無遠弗屆-人人皆知，根據流行病學的研究指出，長期處\r 在重金屬含量過高之地區，易造成生理病變。比方說，長期生活在砷含量高的環境\r 中，易導致肝臟、周邊血管及神經系的損害，各種癌症的發生機率也大為提高；長\r 期處在含量過高的鎘環境中，易引起不正常的鈣代謝﹐產生骨質疏鬆症、軟骨症、\r 糖尿、胺基尿酸、尿蛋白、貧血、和肝功能異常的症狀；而目前坊間所看到各類茶\r 品中含有的兒茶素則被發現具有抗氧化、抗突變及清除自由基等功能。故本實驗以\r 人類胃癌細胞(SC-M1)為材料，以微核(micronuclei)偵測技術觀察細胞長期處理兒茶\r 素((-)-epigallocatechin-3-gallate, EGCG)後，對於亞砷酸鈉(sodium arsenite, NaAsO?)\r 及氯化鎘(cadmium chloride, CdCl?)所造成的細胞遺傳毒性有何影響。另一方面則利\r 用SRB 分析法測量細胞存活率，探討長期處理兒茶素後，亞砷酸鈉及氯化鎘對於細\r 胞的毒殺情況是否改變。實驗結果顯示細胞長期處理兒茶素不會造成微核的增加，\r 但是卻會增加細胞的存活率；單獨處理亞砷酸鈉和氯化鎘則都會使細胞中微核明顯\r 的增加，且會降低細胞的存活率；而長期處理兒茶素的細胞對亞砷酸鈉所誘發的微\r 核有抑制作用且會增加細胞對於亞砷酸鈉的耐受度，長期處理兒茶素無法抑制氯化\r 鎘所誘發的微核與細胞毒性。\r \r \r It is well documented that exposure to heavy metals could cause seriously adverse\r effects to humans. Epidemiological evidence has shown that illness is frequently\r observed in residents living long-term in heavy metal contaminated area. For example,\r long-term exposure of arsenic was associated with increased incidences of liver diseases,\r peripheral vascular and neurological diseases, as well as cancers. And long-term exposed\r to cadmium may lead to abnormal metabolism of calcium, osteoporosis, osteomalacia,\r glucouria, aminoaciduria, proteinuria, anemia and abnormal liver function. Recently,\r numerous reports have shown that (-)-epigallocatechin-3-gallate (EGCG), the major\r polyphenol from green tea, have ability to anti-oxidative stress and anti-mutagenesis. In\r this report, we investigated the effects of EGCG long-term exposure in sodium arsenite\r and cadmium chloride induces chromosomal damages and cytotoxicity in a gastric cancer\r cell line, SC-M1. Our present results demonstrated cells long-term exposure to EGCG did\r not induce micronuclei (MN) formation but induce the growth rate. Sodium arsenite or\r cadmium chloride alone significantly induced MN formation and cytotoxicity in cells\r without long-term EGCG exposure. However, long-term treatment of SC-M1 cells with\r EGCG significantly reduced MN formation and protects the cells from cytotoxicity\r induced by arsenite. Long-term exposure of EGCG had no effect on MN induction and\r cell survival in cadmium-treated SC-M1 cells.