人参皂苷Rg1对成体干细胞特性与功能的影响

人参皂苷Rg1(ginsenoside Rg1,Rg1)是从人参中提取的一种重要单体成分,具有多种药理学活性,可通过多种作用机制对造血干细胞、间充质干细胞、神经干细胞和内皮祖细胞等的增殖、分化、衰老、分泌等产生明显调控作用,在组织器官损伤和机体衰老中产生明显治疗效果,该文就Rg1对成体干细胞特性与功能的影响进行了综述。     

人参皂苷Rg1对培养大鼠骨髓间充质干细胞增殖影响的机制研究

目的研究人参皂苷Rg1对大鼠骨髓间充质干细胞(BMSC)增殖影响的可能机制。方法分离培养大鼠骨髓间充质干细胞,分为药物干预组、对照组,药物干预组以1×10-6mol.L-1人参皂苷Rg1孵育48h,对照组未加药物常规培养;分别用骨髓CFU-F体外培养法、胸腺嘧啶核苷参入法及MTT法测定大鼠BMSC的增殖情况,同时测定BMSC的GATA转录因子1～3的表达及其与DNA结合活性。结果人参皂苷Rg1刺激后BMSC的GATA1和GATA2 mRNA表达与对照组相比分别上调1.42±0.31(P<0.01)和2.70±0.73(P<0.01)倍,并且人参皂苷Rg1刺激后BMSC的GATA与DNA结合活性明显增高。结论人参皂苷Rg1可促进大鼠BMSC增殖,其机制可能是通过上调GATA1和GATA2的表达以及其与DNA的结合活性来实现。     

人参总皂苷增强成骨分化的间充质干细胞促造血作用研究

目的观察人参总皂苷(TSPG)诱导间充质干细胞向成骨细胞分化的作用,探讨TSPG增强成骨分化的间充质干细胞促造血的可能机制。方法贴壁法培养人源骨髓间充质干细胞(h MSCs),成骨细胞分化和免疫表型进行鉴定。不同剂量的TSPG联合成骨细胞条件诱导液培养h MSCs,MTT法检测细胞增殖活性,对-硝基苯磷酸盐(p NPP)法检测培养上清碱性磷酸酶含量,茜素红染色法观察钙结节数量,Western blot法检测成骨细胞分化转录因子-核心结合蛋白因子2(RUNX2)蛋白表达水平,Elisa法检测培养上清造血相关因子含量,造血祖细胞集落生成实验检测培养上清造血支持能力。结果 MTT和p NPP结果均显示随着TSPG剂量增加,吸光值逐渐增加,呈剂量依赖性。钙结节数量和RUNX2蛋白表达水平明显高于对照组。造血相关生长因子和造血祖细胞集落数明显高于对照组。结论TSPG通过上调RUNX2蛋白表达诱导h MSCs向成骨细胞分化,同时增强成骨分化的MSCs支持造血。     

人参皂苷Rg1及其肠内菌代谢产物Rh1对小鼠免疫细胞功能的影响

目的初探人参皂苷Rg1及其肠内菌代谢产物Rh1对正常小鼠免疫功能的影响.方法用Rh1与Rg1分别处理脾T细胞,B细胞及腹腔巨噬细胞(Mφ);MTT比色法测T和B细胞增殖能力;中性红比色法测Mφ的吞噬功能;Griess法测Mφ释放NO的水平.结果 Rh1能促进脾细胞增殖、下调Con A诱导的T细胞增殖;Rh1与Rg1对LPS诱导的B细胞增殖均无明显作用;Rg1和Rh1能提高Mφ的吞噬能力和促进NO的释放.结论 Rg1及其代谢产物Rh1可共同作用于T细胞和Mφ而产生免疫调节作用.     

钙敏感受体对高糖诱导的肾动脉平滑肌细胞增殖的影响

目的 探讨钙敏感受体(CaSR)对高糖诱导的肾动脉平滑肌细胞增殖的影响,并分析其与细胞外调节蛋白激酶1,2(ERK1,2)信号通路的相关性.方法 将对数生长期的肾动脉平滑肌细胞随机分为4组:正常组、模型组、干预-1组、干预-2组及干预-3组.干预-1组、干预-2组和干预-3组分别加入GdCl3(钙敏感受体激动剂)30μ...     

人参皂苷Rg1对脑缺血沙土鼠神经干细胞存活率和学习记忆能力的影响

目的 观察人参皂苷Rg1对脑缺血沙土鼠海马区干细胞存活率以及动物学习记忆能力的影响。方法 6min的短暂性全脑缺血之后3～5周之内，依次通过避暗实验和Morris水迷宫实验观察缺血对动物学习记忆能力的影响；并用组织学和免疫组织化学的方法观察缺血发生后40d时动物海马区神经元的损伤程度以及齿状回区存活下来的干细胞数目。结果 长期给予人参皂苷Rg1可以显著提高海马区新生功能细胞的存活率，保护CA1区神经元细胞免受缺血性损害；同时明显改善全脑缺血对沙土鼠被动回避记忆能力造成的损伤，并提高动物的空间学习记忆能力。结论人参皂苷Rg1可以有效改善或提高脑缺血沙土鼠的学习记忆能力，其机制可能与促进海马区神经再生功能以及保护CA1区神经元有关。     

人参茎叶皂苷对毛囊间充质干细胞增殖的影响

目的:研究人参茎叶皂苷对毛囊间充质干细胞(hair follicle mesenchymal stem cell)的促增殖作用。方法:采用MTT法检测其是否增殖,筛选人参茎叶皂苷对毛囊间充质干细胞促增殖作用的有效浓度,流式细胞术研究加药后细胞周期。结果:当人参皂苷浓度为12.5μg/mL时对毛囊间充质干细胞的促增殖作用最强。结论:毛囊间充质干细胞是毛囊内发育成毛发的主要细胞之一,人参茎叶皂苷可能通过促进毛囊间充质干细胞增殖而促进毛发生长。     

人参皂苷Rg1对慢性应激抑郁模型大鼠谷氨酸及其受体表达的影响

目的：观察人参皂苷Rg1对慢性应激抑郁模型大鼠脑内海马、前额叶皮质区谷氨酸及其不同类型受体表达的影响，探讨其潜在的抗抑郁机制。方法：将SD大鼠随机分为5组：正常组、模型组、氟西汀组（10 mg·kg^-1）、人参皂苷Rg1低、高剂量组（25、50 mg·kg^-1）。采用慢性不可预见性温和应激的方法建立抑郁大鼠模型，于造模同时灌胃给药，共21天。造模结束后采用Morris水迷宫和旷场实验评价大鼠的抑郁样行为，HE染色观察大鼠海马、前额叶皮质区病理改变情况，HPLC法检测谷氨酸含量，Western-blotting法检测离子型谷氨酸受体NMDAR1、代谢型谷氨酸受体mGluR1的蛋白表达情况。结果：与正常组比较，模型组大鼠抑郁样行为显著，海马、前额叶皮质区均存在较为明显的损伤，谷氨酸含量显著升高，NMDAR1、mGluR1蛋白表达均显著上调；在给予人参皂苷Rg1干预后，模型大鼠的抑郁样行为得到缓解，海马、前额叶皮质区损伤减轻，谷氨酸含量下降，NMDAR1、mGluR1蛋白表达水平明显逆转。结论：人参皂苷Rg1对大鼠抑郁症状有明显的改善作用，并能减轻海马和前额叶皮质损伤，其机制可能与调节脑内谷氨酸含量，并抑制其受体表达有关。     

阿片受体泛素化机制及其对受体功能的影响

阿片受体是一类重要的G蛋白偶联受体(GPCR),是内源性阿片肽及阿片类药物结合的靶点,阿片受体激活后对神经系统、免疫及内分泌系统具有调节作用。但阿片受体在反复激活后,容易出现耐受,导致阿片成瘾。受体的内吞和再循环对受体复敏具有重要意义。近年来研究发现,受体的泛素化修饰参与了GPCR的转运过程,并且多数配体作用于阿片受体后,受体的泛素化水平明显升高。将阿片受体的泛素化位点突变后,对不同阿片受体亚型的内吞和降解过程产生了不同的影响,进而影响了阿片受体的信号转导过程。本文着重对阿片受体3种亚型的泛素化修饰特点及泛素化对受体转运的调节作用进行综述。     

重组人红细胞生成素对骨髓间充质干细胞红细胞生成素受体的上调作用

目的研究重组人红细胞生成素(rhEpo)处理骨髓间充质干细胞(MSCs)后对Epo受体(EpoR)的影响。方法含rhEpo0,5及10kU.L-1的培养基培养MSCs24,48及72h后,MTT法检测细胞增殖;6d后,免疫荧光染色检测EpoR阳性的细胞百分率。rhEpo预处理24h,再缺氧处理48h,Hoechst染色,通过形态变化检测细胞凋亡率;rhEpo预处理6d,再缺氧处理48h,Western蛋白印迹法检测EpoR,磷酸化Janus激酶2(p-Jak2),磷酸化转导及转录活化蛋白(p-Stat5)及缺氧诱导因子-1a(Hif-1a)蛋白表达。结果MTT结果显示,rhEpo处理的MSCs增殖能力增强;免疫荧光结果显示,随rhEpo浓度的增加,EpoR阳性细胞数增加;对照组,rhEpo5及10kU.L-1组EpoR阳性细胞百分率分别为(8.3±4.2)%,(24.7±8.1)%和(30.8±10.5)%。rhEpo预处理能增强MSCs抗缺氧凋亡的能力,缺氧处理后,对照组、rhEpo5及10kU.L-1组细胞核固缩率分别为(42.2±8.7)%,(21.9±8.0)%和(20.1±7.9)%。Western蛋白印迹结果显示,rhEpo预处理及预处理后行低氧培养的MSCs,随rhEpo浓度的增加,EpoR及下游抗细胞凋亡蛋白p-Jak2,p-Stat5和Hif-1a蛋白表达增加。结论rhEpo可以促进MSCEpoR的表达,并增加EpoR下游抗细胞凋亡蛋白的表达。     

Clinical utility of calcimimetics targeting the extracellular calcium-sensing receptor (CaSR)

Calcimimetics, which activate the extracellular calcium (Ca_o²⁺)-sensing receptor in the parathyroid and other tissues participating in Ca_o²⁺ homeostasis, were the first described allosteric activators of a G-protein-coupled receptor. Cinacalcet, the only calcimimetic currently approved for human use, is used clinically for treating secondary hyperparathyroidism (e.g., overactivity of parathyroid glands) in patients being dialyzed for chronic kidney disease. By sensitizing the parathyroids to Ca_o²⁺, cinacalcet lowers the circulating parathyroid hormone (PTH) level. It also reduces serum calcium and phosphate, changes increasing the percentage of patients achieving the guidelines recommended by the National Kidney Foundation (NKF) for these minerals. Studies are underway addressing whether better adherence to these guidelines in patients receiving cinacalcet reduces cardiovascular disease and related mortality, which are both common is the dialysis population. The second approved use of cinacalcet is for treating hypercalcemia in patients with inoperable parathyroid carcinoma. In this setting, it provides the first medical therapy chronically lowering serum calcium concentration in this condition, albeit not to normal in most patients. Its effect on the long-term prognosis of these patients, if any, is presently unclear. “Off-label” administration of cinacalcet [i.e., not yet approved by the US Food and Drug Administration (FDA)] effectively lowers serum calcium and/or PTH in various other forms of hyperparathyroidism and increases serum phosphate in renal phosphate-wasting syndromes by reducing PTH-induced phosphaturia. In the future, the drug could conceivably be utilized to modulate the activity of the CaSR in other tissues (i.e., kidney, colon) in therapeutically desirable ways.     

体外培养成人脂肪间充质干细胞生物学特性及诱导分化为心肌细胞的研究

目的通过分离、培养脂肪间充质干细胞观察其生物学特性及诱导分化为心肌细胞,为心肌再生提供良好的干细胞来源。方法胶原酶消化分离成人脂肪来源的间充质干细胞并进行传代培养,倒置相差显微镜观察细胞形态,流式细胞仪测定CD29、CD31、CD34、CD44及细胞周期,MTT绘制细胞生长曲线。用第3代细胞进行诱导分化,观察不同浓度5-氮杂胞苷(5-Aza,1,3,5,10,15,20μmol/L)及不同作用时间(12,24,48,72h)诱导其向心肌细胞分化的差别,采用最佳浓度10μmol/L,最佳作用时间24h进行实验,分别在第7,14,21,28天用免疫细胞荧光染色鉴定心肌细胞α-横纹肌、肌球蛋白重链(MHC)、心肌肌钙蛋白I(cTnI)表达,第14天反转录-聚合酶链反应(RT-PCR)法检测心肌发育相关基因NKX2.5的表达。结果倒置相差显微镜下观察原代细胞,可见细胞呈梭型、核圆形或椭圆形,偶见双核。传代细胞核原代细胞形态相似,排列有了一定的方向性。流式细胞仪检测结果显示,第1、3、5代细胞均高表达CD29和CD44;而CD31始终表达很弱,可认为呈阴性表达;CD34在第1、3代细胞弱表达,在第5代细胞表达逐渐减弱为阴性。细胞生长曲线显示前3d处于细胞潜伏状态,第4天进入对数生长期,第10天达到顶峰。细胞周期检测结果显示G1期细胞为85.93%,S期为7.24%,G2期为6.83%。10μmol/L5-Aza诱导后7d进行免疫细胞荧光染色,未见有α-横纹肌、MHC、cTnI表达。14d少量细胞α-横纹肌和MHC阳性表达,cTnI阴性表达。21d表达α-横纹肌和MHC的细胞数量增多,并可见少量cTnI阳性表达。28dα-横纹肌、MHC、cTnT阳性表达数目均增多,RT-PCR结果显示NKX2.5呈阳性表达。结论成人脂肪中可以分离出脂肪间充质干细胞并且可以在体外培养传代,经过5-Aza的诱导可以向心肌细胞分化,为干细胞移植治疗和组织工程学种子细胞提供了更多的选择。     

Markers of adult tissue-based stem cells

The expectation generated by the pluripotentiality of embryonic stem (ES) cells has initiated a renaissance in stem cell biology. While ES cells can be harvested in abundance and appear to be the most versatile of cells for regenerative medicine, adult stem cells also hold promise, but the identity and subsequent isolation of these comparatively rare cells remains problematic in most tissues, perhaps with the notable exception of the bone marrow. Identifying surface molecules (markers) that would aid in stem cell isolation is thus a major goal for stem cell biologists. Moreover, the characterization of normal stem cells in specific tissues may provide a dividend for the treatment of cancer. There is a growing belief that the successful treatment of neoplastic disease will require specific targeting of the cancer stem cells, cells that may well have many of the characteristics of their normal counterparts.     

Immunohistochemical and functional studies on calcium-sensing receptors in rat uterine smooth muscle

1. Activation of calcium‐sensing receptors (CaS) leads to relaxation of vascular smooth muscle. However, the role of CaS in uterine smooth muscle is unknown. Therefore the aim of the present study was to investigate the expression and function of CaS in the uterus. 2. The expression of CaS in the oestrogen‐dominated rat uterus was investigated using immunohistochemistry. The effects of putative CaS ligands on oxytocin‐induced contractions of longitudinally orientated uterine strips from oestrogen‐dominated rats were determined at reduced extracellular Ca²⁺concentrations using conventional organ bath techniques. 3. Immunohistochemical evidence showed the presence of CaS in the endometrium and smooth muscle layers of the rat uterus. Oxytocin‐induced contractions were inhibited by cations (Gd³⁺ > Ca²⁺ = Mg²⁺), polyamines (spermine > spermidine) and the positive allosteric modulators cinacalcet and calindol. However (R)‐ and (S)‐cinacalcet were equipotent, indicating a lack of stereoselectivity, and the negative allosteric modulator calhex‐231 also caused dose‐dependent relaxation. In addition, although intermediate‐conductance calcium‐activated potassium channels and cytochrome P450‐dependent signal transduction have been implicated in CaS‐induced relaxation of vascular smooth muscle, neither Tram‐34 nor miconazole (1 μmol/L), which block these pathways, respectively, had any effect on the ability of cinacalcet to inhibit oxytocin‐induced contractions. 4. Calcium‐sensing receptors are expressed in smooth muscle layers of the rat uterus and their ligands produce potent relaxation of longitudinally orientated uterine strips. However, the pharmacological profile of inhibition of contractility by CaS ligands is not consistent with a role for CaS in the regulation of uterine contractility in the rat.     

The role of adult stem cells in carcinogenesis

The role of adult stem cells in tissue regeneration has attracted much interest because of its enormous therapeutic potential. Adult stem cells reside in every tissue of the body and have the ability to self-renew and to give rise to a high number of differentiated progeny. These are indeed the essential steps in tissue regeneration, which in some cases occurs constitutively, whereas in other cases happens in response to an injury. The identification of the key factors involved in self-renewal and differentiation pathways is at the top of the agenda of stem cell biologists. Interestingly, a number of factors that govern the fate of adult stem cells also play a role in malignant cell transformation, such as the Wnt cascade, Oct-4, Bmi-1 and Evi1. In addition, rare subpopulations of cancer stem cells were identified for leukemia and other solid tumors. These rare fractions of cancer stem cells are in large part responsible for maintaining the tumor mass, as they have the capacity to self-renew and to generate a high number of progeny via differentiation program. These findings can be considered a major breakthrough in cancer research. Currently, oncologists and stem cell biologists have two main goals: i) the assessment of the consistency of the line that divides adult stem cells and carcinogenesis; ii) to better characterize the biology of cancer stem cells. This new line of investigation may allow for the development of novel therapeutics and cancer diagnostics.     

骨髓间充质干细胞生物学特性及中药对其生物学行为的影响

目的：综述骨髓问充质干细胞(MSCs)的生物学特性及中药对其生物学行为的影响，探讨中药在MSCs研究中的应用前景。方法：查阅国内外检索类期刊，归纳骨髓MSCs的生物学特点及中药对其影响。结果：骨髓MSCs容易获取、可以体外大量扩增、干细胞特性不易丧失，是组织工程和细胞治疗中理想的种子细胞，中药可诱导骨髓MSCs定向分化成神经元。结论：中药对骨髓MSCs的生物学特性有影响，并有待深入研究。