神经干细胞移植治疗结肠去神经节小鼠

目的 观察神经干细胞在去神经节小鼠结肠壁内的存活分化,探讨神经干细胞移植治疗结肠无神经节细胞症的可行性.方法 0.5%苯扎氯铵(BAC)处理8周龄昆明小鼠结肠浆膜层选择性去除结肠肇神经节制作巨结肠模型,原代培养新生小鼠大脑皮质来源神经干细胞,Hoechsd3342标记传代纯化后神经干细胞.运用微量注射器将标记后的神经干细胞移植入模型鼠病变肠段,分别于术后1、2、3、4周行大体观察,苏木素-伊红(HE)染色,免疫组织荧光检测小鼠生物学特性和神经干细胞存活分化情况.结果 原代培养神经干细胞Nestin表达阳性,体外培养可分化为神经元和神经胶质细胞;BAC处理后,HE染色及免疫组织化学染色显示小鼠结肠肌间及黏膜下神经节消失;神经干细胞移植后各观测时间点可见荧光标记细胞,免疫组织荧光检测显示术后1周结肠壁存在巢蛋白(Nestin)表达阳性细胞,3周后可见神经元特异性烯醇化酶(NSE)及胶质纤维酸性蛋白(GFAP)表达阳性细胞,对照组未观察到阳性表达.结论 神经干细胞可以在去神经节小鼠结肠肇内存活并分化为神经元及胶质细胞,部分恢复肠道神经的调节作用.     

基质细胞衍生因子受体4在肌损伤组织肌卫星细胞的表达

目的 探讨注射心脏毒素后肌损伤的肌卫星细胞中基质细胞衍生因子受体4(CXC chemokinereceptor 4,CXCR4)的表达情况,为进一步研究肌肉退行性疾病的分子学发病机制和治疗方法提供理论依据.方法 取C57雄性小鼠12只,于左侧股四头肌局部注射心脏毒素(5 μg/只),建立小鼠肌损伤模型:右侧股四头肌作为自身对照.于注射后1、4 d及1、2、4、6周处死小鼠,分离两侧股四头肌,取材行HE染色、免疫组织化学染色及RT-PCR检测分析CXCR4表达情况.结果 HE染色示肌肉组织从损伤修复到再生的全过程.免疫组织化学染色检测示注射心脏毒素后1、4 d和1、2、4、6周,肌肉组织内CXCR4表达分别为1 955.6±150.3、2 223.2±264.3、2 317.6±178.7、3 066.5±269.6、1 770.9±98.7和1 505.7±107.1,与正常肌肉组织(640.3±124.0)比较,差异均有统计学意义(P<0.001).RT-PCR检测显示,正常肌肉组织、注射心脏毒素后1、4 d和1、2、4、6周肌肉组织内CXCR4 mRNA表达分别为0.349±0.006、0.822±0.013、0.882±0.025、1.025±0.028、1.065±0.041、0.837±0.011和0.777±0.015;肌损伤后各时间点与正常肌肉组织比较,差异均有统计学意义(P<0.001).结论 CXCR4可能在肌肉损伤修复过程中起重要作用.     

辛伐他汀在骨髓基质干细胞向成骨细胞分化过程中的作用

目的 通过对小鼠骨髓干细胞体外培养的观察，研究辛伐他汀在骨髓基质干细胞向成骨细胞定向分化过程中的作用。方法 取雄性6周ICR小鼠股骨骨髓基质细胞进行原代和传代培养，应用组织化学及yon Kossa方法检测细胞碱性磷酸酶染色和细胞外基质矿化；在细胞培养早期加入辛伐他汀(实验组)或保持基础培养条件(对照组)，应用半定量RT-PCR方法分别检测两组Ⅰ型胶原蛋白(COL1)、碱性磷酸酶(ALP)、转录因子CBFA1和Osterix(OSX)在成骨细胞分化过程中的表达。结果 小鼠骨髓基质细胞经体外诱导后分化为具备碱性磷酸酶活性和矿化细胞外基质的成熟成骨细胞。实验组COL1、ALP和CBFA1表达在细胞培养第3，5天均高于对照组，OSX表达差异不明显。结论 辛伐他汀在成骨细胞分化过程中促进其相关基因的表达。     

大鼠阴茎海绵体肌源性干细胞的分离与表型鉴定

目的 探讨阴茎海绵体中肌源性干细胞(MDSCs)的分离与表型鉴定的方法.方法 取2个月龄SD大鼠阴茎海绵体组织,用0.5％Ⅰ型胶原酶、0.1％胰蛋白酶进行酶消化初步分离.应用改良的Preplate差速贴壁法进一步行细胞纯化,细胞培养1h,贴壁细胞为PP1;未贴壁细胞转瓶培养2h,贴壁细胞为PP2;未贴壁细胞再次转瓶培养18h,贴壁细胞为PP3;此后,每次间隔24h转瓶培养依次获得的贴壁细胞为PP4、PP5、PP6,观察细胞形态变化.流式细胞仪检测PP3、PP6细胞中干细胞抗原l (Sca-l)和结蛋白(Desmin)的阳性表达量;Western blot检测PP1 ～ PP6细胞中Sca-1和Desmin的阳性表达;免疫荧光细胞化学法检测Sca-1、Desmin、Sca-1/Desmin在PP6细胞中的表达.结果 PP1～ PP6细胞贴壁能力逐渐减慢,PP6细胞贴壁最慢,2～3d后才开始贴壁成圆形或短梭形.流式细胞仪检测结果显示,PP3细胞中Sca-1阳性表达量为(0.3±0.2)％,与同型对照组比较差异无统计学意义(P＞0.05),Desmin阳性表达量为(15.3±1.5)％,与同型对照组比较差异有统计学意义(P＜0.05);PP6细胞中Sca-1、Desmin阳性表达量分别为(5.7±0.7)％、(41.1±1.6)％,与PP3比较差异均有统计学意义(P＜0.05).Western blot显示PP1 ～ PP5细胞中未检测到Sca-1蛋白明显表达,但在PP6细胞中则检测到Sca-1蛋白的表达,Desmin蛋白在PP1 ～ PP6细胞中表达逐渐增强.免疫荧光细胞化学显示在PP6细胞中有少量细胞表达Sca-1、散在分布、以胞质表达为主;表达Desmin细胞聚集、数量较多、主要表达于胞质;亦发现有极少量双阳性标记细胞(Sca-1/Desmin),共同表达于同一细胞的胞质.结论 在大鼠阴茎海绵体中分离出既有于细胞表型又有肌源性表型的细胞,提示此类细胞为MDSCs.     

体外诱导毛囊干细胞成血管平滑肌细胞的实验研究

目的探讨体外诱导人毛囊干细胞成血管平滑肌细胞的可行性。方法采用中性蛋白酶(Dispase)分离人毛囊干细胞,用含10 ng/mL PDGF-BB、10%血清的低糖DMEM诱导液对其进行诱导,无PDGF-BB的培养液为对照组,观察每代细胞形态,诱导4代后检测α-平滑肌肌动蛋白(α-SM actin)与肌钙结合蛋白(Calponin)的表达。结果在诱导液的作用下,细胞形态逐步向平滑肌样转变,对照组细胞形态改变不显著。细胞免疫荧光检测显示,至第4代,实验组已明显表达α-SM actin与Calponin,对照组表达不明显;流式细胞仪检测显示,实验组α-SM actin与Calponin阳性表达率近50%,对照组则低于8%;RT-PCR显示,实验组表达Calponin,而对照组未见明显表达。结论使用含10 ng/mLPDGF-BB的低糖DMEM培养液可体外诱导人毛囊干细胞成血管平滑肌细胞。     

痩素在骨髓基质干细胞向成骨细胞分化早期的作用研究

目的 研究小鼠骨髓基质干细胞体外增生及向成骨细胞定向分化早期瘦素(Leptin)的作用。方法 取雄性6周ICR小鼠股骨骨髓基质细胞进行原代和传代培养，在传代细胞培养时加入Leptln(实验组)或保持基础培养条件(对照组)，分别检测两组的细胞增生情况。半定量RT-PCR方法检测成骨细胞相关基因Cbfal和Cbtb等在两组细胞分化过程中的表达。结果 实验组在细胞培养24和48h细胞数量明显少于对照组，显示时间与Leptin剂量依赖特性。Leptln在传代细胞培养中促进成骨细胞特异性转录因子Cbfal和Cbtb的表达。结论 Leptin抑制骨髓基质干细胞体外增生并促进早期成骨细胞相关基因的表达。     

应力刺激在肩袖损伤修复中作用机制的实验研究

目的 探讨应力刺激在肩袖损伤后修复过程中的作用机制. 方法选用成年雄性SD大鼠32只,随机分为实验组和对照组(n=16).将冈上肌腱于大结节止点处横断后原位缝合,建立大鼠冈上肌腱损伤模型(Carpenter模型).术后制动1周后,实验组开始转笼跑步实验,对照组笼中自由活动.于术后2、4、8、16周取材(每个时间点4只),分别比较两组肌腱-骨界面的组织学改变、血管性血友病因子(vWF)免疫组化显示的血管增生及细胞粘合素-C(TN-C)的表达变化. 结果修复早期(术后2～4周)肌腱-骨界面的组织形态学、血管生成和TN-C的表达两组均无明显差别;术后8周,实验组肌腱-骨界面的组织形态学恢复较好且血管生成多于对照组;术后16周,实验组TN-C的表达明显多于对照组,差异均有统计学意义(P<0.05). 结论适当的应力刺激可能促进血管生成及TN-C的表达而有利于肩袖损伤后肌腱-骨界面的修复,在肩袖损伤的修复过程中发挥重要作用.     

骨髓干细胞转分化为肾祖细胞并参与修复急性肾脏损伤的研究

目的 观察骨髓干细胞是否可以向肾祖细胞转分化,成为肾脏祖细胞库的肾外来源;验证粒细胞集落刺激因子(G-CSF)是否可以促进骨髓干细胞向肾脏祖细胞的转分化,提高肾脏修复的效能.方法 6周龄全身表达绿色荧光蛋白(GFP)的C57BL/6J转基因小鼠提供骨髓,6~8周龄同种无荧光标记的C57BL/6J小鼠40只作为骨髓受体.骨髓移植前,受体小鼠接受致死剂量的γ放射线137Cs照射,骨髓重建情况经流式细胞仪检测确认.骨髓重建完毕后所有小鼠均接受单侧肾脏缺血再灌注损伤.干细胞动员效果及向肾脏归巢情况经流式细胞仪检测鉴定.损伤4、8周后取肾脏标本行免疫荧光组织化学染色,观察骨髓来源的肾脏祖细胞数以及骨髓细胞在微血管形成中的作用.损伤4周后通过组织切片免疫荧光组织化学方法观察并计数微血管细胞数.结果 G-CSF动员1 d后,分别为CD29、CD34、Sca-1、c-Kit、Flk-1阳性的干细胞占外周血非红系细胞的比例均高于对照组(P<0.05).损伤4周后,G-CSF动员组的肾脏中,骨髓来源并且分别表达Sca-1/GFP、CD29/GFP的干细胞的比例均高于对照组(P<0.05);在损伤4周及8周后,肾脏切片免疫荧光组织化学显示G-CSF动员肾脏中骨髓来源的肾祖细胞即Sca-1/GFP双阳性的细胞数量高于对照组.损伤4周后,动员组肾脏中表达CD31的微血管密度高于对照组(P<0.05).损伤4周后肾脏组织中存在CD105/GFP及α-SMA/GFP双阳性的细胞.结论 ①骨髓干细胞可以转分化为器官特异性干细胞-肾脏祖细胞;②G-CSF可以加速这一转分化的过程,并使损伤肾脏得到更好的修复.     

大段感染骨煮沸后异位再血管化的实验研究

[目的]探讨大段感染骨经煮沸后异位再血管化的可行性。[方法]将120只健康6个月龄中国白兔随机分为实验组、对照组各60只。实验组:首先制备兔胫骨感染模型,然后截取2.0 cm长感染胫骨,经煮沸灭菌后,异位于对侧大腿股直肌与股内侧肌间隙之隐动脉处,1.0克氏针固定于股骨上。对照组:在同一部位截取相同长度的无菌胫骨段经生理盐水浸泡处理后,余步骤同实验组。两组分别于术后0、4、6、8、10、12周各处死10只兔子,通过大体标本观察及免疫组织化学染色法检测异位血管化骨CD34阳性血管数和血管内皮生长因子(vascular endothelial growth factor,VEGF)蛋白表达量的灰度值,分析判断两组血管化情况。[结果]术后4、6、8周,实验组CD34阳性血管数均低于对照组(P0.05),其VEGF蛋白表达量也均低于对照组,但仅术后8周差异有统计学意义(P0.05);术后10、12周,实验组CD34及VEGF检测结果均稍高于对照组,但差异均无统计学意义(P0.05)。实验组和对照组CD34阳性血管数及VEGF蛋白表达量分别在术后10、8周达到峰值,之后均成下降趋势。此时,两组异位血管化骨几乎完全被软组织包裹;两者贴附紧密,分离困难。[结论]自体正常骨在术后8周完成再血管化,要快于煮沸骨,而煮沸骨在术后10周也完成再血管化。证实兔大段感染胫骨经煮沸灭菌后异位于肌肉丰富的知名血管处,使其再血管化,转化为血管化骨是可行的。     

生精障碍BALB/c小鼠睾丸组织的体外培养研究

目的:探寻生精障碍小鼠睾丸组织生精能力的体外发育与成熟方法。方法:8周龄BALB/c雄性小鼠68只,随机分为4组,每组17只。对照组为正常同龄BALB/c雄性小鼠睾丸组织,实验组分别采用注射40 mg/kg白消安后第4周睾丸组织为SCOS组,第6周睾丸组织为重度H-S(H-S1)组,第8周睾丸组织为轻度H-S(H-S2)组。琼脂糖凝胶法体外培养3种生精障碍小鼠睾丸组织及对照组睾丸组织至第4周,通过免疫组化检测减数分裂过程中标记蛋白[减数分裂启动:维甲酸诱导蛋白8(STRA8);减数分裂中:联会复合蛋白3(SCP3);减数分裂后:转换蛋白1(TNP1)]的表达情况,判断体外培养过程中生殖细胞的发育与成熟能力; TUNEL法检测培养前后生殖细胞凋亡情况。结果:①培养前与对照组相比,睾丸组织损伤越严重其STRA8的表达越少(P0.05);随着培养时间的延长,在培养4周后3个实验组中STRA8的表达呈上升趋势(P0.05)。②培养前与对照组相比,SCOS组SCP3表达最少、H-S2表达最多(P0.05);培养4周后SCP3表达增加,但仍未达到对照组表达水平,且损伤越严重,表达越少;③培养4周后TNP1在对照组有阳性表达,H-S1、H-S2组可见个别阳性表达(P0.05),SCOS组无表达。④与培养前相比,培养4周后SCOS组凋亡增加,H-S组凋亡减少(P0.05)。结论:琼脂糖凝胶体外培养可以诱导生精障碍的BALB/c小鼠睾丸组织进行减数分裂,生精功能损伤较轻者的体外培养效果好。     

Injection of amniotic fluid stem cells delays progression of renal fibrosis

Injection of amniotic fluid stem cells ameliorates the acute phase of acute tubular necrosis in animals by promoting proliferation of injured tubular cells and decreasing apoptosis, but whether these stem cells could be of benefit in CKD is unknown. Here, we used a mouse model of Alport syndrome, Col4a5(-/-) mice, to determine whether amniotic fluid stem cells could modify the course of progressive renal fibrosis. Intracardiac administration of amniotic fluid stem cells before the onset of proteinuria delayed interstitial fibrosis and progression of glomerular sclerosis, prolonged animal survival, and ameliorated the decline in kidney function. Treated animals exhibited decreased recruitment and activation of M1-type macrophages and a higher proportion of M2-type macrophages, which promote tissue remodeling. Amniotic fluid stem cells did not differentiate into podocyte-like cells and did not stimulate production of the collagen IVa5 needed for normal formation and function of the glomerular basement membrane. Instead, the mechanism of renal protection was probably the paracrine/endocrine modulation of both profibrotic cytokine expression and recruitment of macrophages to the interstitial space. Furthermore, injected mice retained a normal number of podocytes and had better integrity of the glomerular basement membrane compared with untreated Col4a5(-/-) mice. Inhibition of the renin-angiotensin system by amniotic fluid stem cells may contribute to these beneficial effects. In conclusion, treatment with amniotic fluid stem cells may be beneficial in kidney diseases characterized by progressive renal fibrosis.     

Amniotic fluid as a rich source of mesenchymal stromal cells for transplantation therapy

Stem cells isolated from amniotic fluid are known to be able to differentiate into different cells types, thus being considered as a powerful tool for cellular therapy of different human diseases. In the last 4 years, amniotic fluid-derived stem (AFS) cells have been shown to express embryonic and adult stem cell markers. These cells can be considered an intermediate stage between embryonic stem cells and adult stem cells. AFS cells can give rise to adipogenic, osteogenic, myogenic, endothelial, neurogenic, and hepatic lineages, inclusive of all embryonic germ layers. AFS cells have a high renewal capacity and can be expanded for over 250 doublings without any detectable loss of chromosomal telomere length. Taken together, all these data provide evidence that amniotic fluid represents a new and very promising source of stem cells for research, as well as clinical applications. Certainly stem cells from amniotic fluid will be useful both for a customized cell supply for newly born children and for banking cells to be used for therapeutic cell transplantation in immunogically matched recipients. Further investigations are also warranted to fully explore the amniotic cells' potential for adult human disorders.     

Autologous transplantation of amniotic fluid-derived mesenchymal stem cells into sheep fetuses

Long-term engraftment and phenotype correction has been difficult to achieve in humans after in utero stem cell transplantation mainly because of allogeneic rejection. Autologous cells could be obtained during gestation from the amniotic fluid with minimal risk for the fetus and the mother. Using a sheep model, we explored the possibility of using amniotic fluid mesenchymal stem cells (AFMSCs) for autologous in utero stem cell/gene therapy. We collected amniotic fluid (AF) under ultrasound-guided amniocentesis in early gestation pregnant sheep (n = 9, 58 days of gestation, term = 145 days). AFMSCs were isolated and expanded in all sampled fetal sheep. Those cells were transduced using an HIV vector encoding enhanced green fluorescent protein (GFP) with 63.2% (range 38.3-96.2%) transduction efficiency rate. After expansion, transduced AFMSCs were injected into the peritoneal cavity of each donor fetal sheep at 76 days under ultrasound guidance. One ewe miscarried twin fetuses after amniocentesis. Intraperitoneal injection was successful in the remaining 7 fetal sheep giving a 78% survival for the full procedure. Tissues were sampled at postmortem examination 2 weeks later. PCR analysis detected GFP-positive cells in fetal tissues including liver, heart, placenta, membrane, umbilical cord, adrenal gland, and muscle. GFP protein was detected in these tissues by Western blotting and further confirmed by cytofluorimetric and immunofluorescence analyses. This is the first demonstration of autologous stem cell transplantation in the fetus using AFMSCs. Autologous cells derived from AF showed widespread organ migration and could offer an alternative way to ameliorate prenatal congenital disease.     

人羊水间充质干细胞的分离鉴定及其对抗Thy-1肾炎的治疗作用

探讨羊水间充质干细胞(amniotic fluid mesenchymal stem cells,AF-MSCs)对抗Thy-1肾炎模型的治疗作用。 方法采用差异性贴壁与机械性分离法从人孕中期羊水中分离出羊水间充质干细胞,流式细胞术鉴定其表面标志物,成脂、成骨诱导分化检测其分化能力。利用尾静脉注射抗Thy-1抗体建立SD大鼠抗Thy-1系膜增生性肾炎模型;将第5代羊水间充质干细胞通过尾静脉注射治疗抗Thy-1系膜增生性肾炎大鼠,检测大鼠尿蛋白的变化,PAS染色观察大鼠肾脏病理改变。 结果羊水间充质干细胞顺利分离,流式结果显示其表达间充质干细胞标志物(CD29、CD44、CD73、CD90、CD105)和胚胎干细胞标志物(SSEA-4)而不表达造血干细胞标志物(CD34、CD45、CD133),且在适当条件下能够被诱导分化为脂肪细胞和骨细胞。羊水间充质干细胞治疗后,与模型组相比,治疗组在第7、12天时24 h尿蛋白明显下降(P<0.01),且肾脏病理结果表明系膜细胞增殖减轻,系膜区细胞外基质积聚减少。 结论成功的从人孕中期羊水中分离出羊水间充质干细胞,羊水间充质干细胞治疗系膜增生性肾小球肾炎有效。     

Amniotic fluid and bone marrow derived mesenchymal stem cells can be converted to smooth muscle cells in the cryo-injured rat bladder and prevent compensatory hypertrophy of surviving smooth muscle cells

PURPOSE: Wound healing of the cryo-injured bladder can bring about organ remodeling because of incomplete reconstitution of depleted smooth muscle cells. Stem cell transplantation could be beneficial to improve smooth muscle cell regeneration and/or modulate the remodeling process. The repair of bladder injury using adult-type stem cells would be useful for adult urological patients but unsuited for neonatal patients, in whom major benefits are likely to derive from fetal-type stem cells. MATERIALS AND METHODS: The smooth muscle cell differentiation potential of fetal-type vs adult-type stem cells was evaluated by injecting green fluorescent protein labeled mesenchymal stem cells from rat amniotic fluid or bone marrow, respectively, in cryo-injured rat bladder walls. RESULTS: At 30 days after transplantation only a few fetal-type or adult-type mesenchymal stem cells gave rise to enteric or vascular smooth muscle cells, whereas most mesenchymal stem cells appeared incapable of specific differentiation. In vitro co-culture experiments of smooth muscle cells with fetal-type or adult-type mesenchymal stem cells selectively labeled with distinct fluorochromes showed the presence of hybrid cells, suggesting that some mesenchymal stem cells can undergo cell fusion. Surprisingly the major effect of rat bone marrow or amniotic fluid mesenchymal stem cell transplantation seemed to be preventing cryo-injury induced hypertrophy of surviving smooth muscle cells. CONCLUSIONS: In this model stem cell transplantation has a limited effect on smooth muscle cell regeneration. Instead it can regulate post-injury bladder remodeling, possibly via a paracrine mechanism.     

Feasibility of magnetic resonance spectroscopy for evaluating fetal lung maturity

Background/Purpose

Amniocentesis is an invasive procedure with inherent risks. Magnetic resonance (MR) spectroscopy is a safe noninvasive way of measuring levels of choline-containing compounds (including surfactant) and other metabolites. The purpose of this study was to test the feasibility of assessing fetal lung maturity in vivo and ex vivo using MR spectroscopy to determine differences in amniotic fluid choline concentrations between the second and third trimesters.

Methods

Magnetic resonance spectroscopy was performed on ex vivo samples of amniotic fluid from second- and third-trimester fetuses. In vivo MR spectroscopy was performed on amniotic fluid and fetal lungs in third-trimester fetuses. Spectral acquisition and analysis were performed by an attending radiologist in conjunction with an MR spectroscopist.

Results

Choline-containing compounds were observed from 3.20 to 3.25 ppm. Comparison of spectra from second- and third-trimester amniocentesis revealed a trend toward increased choline at later gestational ages. Spectra from amniotic fluid and lungs of a third-trimester fetus showed that choline can be detected in the in vivo setting.

Conclusions

Magnetic resonance spectroscopy is a safe noninvasive procedure that enables measurement of choline-containing compounds in fetal lung and amniotic fluid. Magnetic resonance spectroscopy shows a trend toward an increased quantity of choline in third- vs second-trimester amniocentesis.     

Trophic effect of amniotic fluid on cultured fetal gastric mucosal cells

This study examines the hypothesis that the growth and development of fetal gastric epithelial cells is critically dependent on the presence of trophic factors in amniotic fluid. Fetal gastric epithelial cells (predominantly parietal cells) were grown in culture in the presence of graded concentrations of rabbit amniotic fluid, fetal bovine serum, or a control solution containing the nutrients specific to amniotic fluid. After 7 days, cells were harvested and growth was assessed by cell counts and DNA contents. Amniotic fluid stimulated growth of these cultured cells with a potency similar to that of fetal bovine serum. Cell growth was significantly enhanced by amniotic fluid at each dose tested, when compared to the appropriate nutrient control group. Cell growth could not be maintained in the absence of amniotic fluid or fetal bovine serum. We conclude that amniotic fluid contains factors which are trophic to the growth of cultured fetal gastric epithelial cells. The nature of these factors remains to be determined.     

Growth stimulatory effects of amniotic fluid and amniotic cell conditioned medium on human cells involved in wound healing

Summary Amniotic membrane has been used successfully as a biological dressing for various kinds of wounds. In order to study exocrine activity in amniotic cells, we assessed the incorporation of 3H-thymidine in human fibroblasts and the increase in the number of human keratinocytes when stimulated with amniotic fluid and conditioned medium from amniotic cells. Both amniotic fluid and conditioned medium were shown to stimulate these cell types, which are crucial to the wound healing process. Amniotic fluid was the most potent of the two media tested. The effect exerted by amniotic fluid and conditioned medium were comparable to that of 10% fetal calf serum and a dose-dependent reponse was seen when the media were diluted. These results indicate that the special healing features seen in fetal wounds bathed in amniotic fluid, together with the wound healing properties of amniotic membrane used as a biological wound dressing, may be due to the exocrine activity of the amniotic cells.Abbreviations ACCM Amniotic cell conditioned medium - AM Amniotic membrane - DMEM Dulbecco's Modified Eagle's medium - FCS Fetal calf serum - HA Hyaluronic acid - PBS Phosphatebuffered saline     

Immune Tolerance of Amniotic Fluid Stem Cell–Induced Rat Kidney Graft and Influences on Oxidative Stress

Objective

This study aimed to use amniotic fluid stem cells of donors to induce immune tolerance of heterogenous rat kidney graft for investigating the formation mechanism of immune tolerance.

Methods

With Wistar rats as donors and Sprague-Dawley (SD) rats as receptors, the heterogenous kidney graft animal model was established, and amniotic fluid stem cells of Wistar rats were isolated and cultured. Moreover, 40 SD rats were randomly divided into 4 groups. Creatinine (Cr), blood urea nitrogen (BUN), interleukin (IL) 2, interferon (IFN) γ, and oxidative stress levels in serum were detected, flow cytometry was used to detect changes of CD4 and CD8 cells, and quantitative changes of urinary protein and pathologic changes of transplanted kidney were observed.

Results

BUN, Cr, IL-2, IFN-γ, and oxidative stress levels and urinary protein quantity in rat serum of the test group were significantly lower than those of the control group, creatinine clearance rate was significantly higher than that of the control group, and renal pathologic injury extent was significantly milder than that of the control group.

Conclusions

Amniotic fluid stem cells can induce immune tolerance of rat kidney graft and inhibit oxidative stress level, improve kidney function, and alleviate kidney injury.     

A comparison of clinically relevant sources of mesenchymal stem cell-derived exosomes: Bone marrow and amniotic fluid

Background/Purpose

Exosomes may constitute a more practical alternative to live cells in select stem cell-based therapies. We sought to compare exosomes from two mesenchymal stem cell (MSC) sources relevant to perinatal and pediatric diseases.