Molecular and phenotypic characterization of human amniotic fluid cells and their differentiation potential

The main goal of the study was to identify a novel source of human multipotent cells, overcoming ethical issues involved in embryonic stem cell research and the limited availability of most adult stem cells. Amniotic fluid cells （AFCs） are routinely obtained for prenatal diagnosis and can be expanded in vitro; nevertheless current knowledge about their origin and properties is limited. Twenty samples of AFCs were exposed in culture to adipogenic, osteogenic, neurogenic and myogenic media. Differentiation was evaluated using immunocytochemistry, RT-PCR and Western blotting. Before treatments, AFCs showed heterogeneous morphologies. They were negative for MyoD, Myf-5, MRF4, Myogenin and Desmin but positive for osteocalcin, PPARgamma2, GAP43, NSE, Nestin, MAP2, GFAP and beta tubulin III by RT-PCR. The cells expressed Oct-4, Rex-1 and Runx-1, which characterize the undifferentiated stem cell state. By immunocytochemistry they expressed neural-glial proteins, mesenchymal and epithelial markers. After culture, AFCs differentiated into adipocytes and osteoblasts when the predominant cellular component was fibroblastic. Early and late neuronal antigens were still present after 2 week culture in neural specific media even if no neuronal morphologies were detectable. Our results provide evidence that human amniotic fluid contains progenitor cells with multi-lineage potential showing stem and tissue-specific gene/protein presence for several lineages.

Osteogenic differentiation of amniotic fluid mesenchymal stromal cells and their bone regeneration potential

In orthopedics, tissue engineering approach using stem cells is a valid line of treatment for patients with bone defects. In this context, mesenchymal stromal cells of various origins have been extensively studied and continue to be a matter of debate. Although mesenchymal stromal cells from bone marrow are already clinically applied, recent evidence suggests that one may use mesenchymal stromal cells from extra-embryonic tissues, such as amniotic fluid, as an innovative andadvantageous resource for bone regeneration. The use of cells from amniotic fluid does not raise ethical problems and provides a sufficient number of cells without invasive procedures. Furthermore, they do not develop into teratomas when transplanted, a consequence observed with pluripotent stem cells. In addition, their multipotent differentiation ability, low immunogenicity, and anti-inflammatory properties make them ideal candidates for bone regenerative medicine. We here present an overview of the features of amniotic fluid mesenchymal stromal cells and their potential in the osteogenic differentiation process. We have examined the papers actually available on this regard, with particular interest in the strategies applied to improve in vitro osteogenesis. Importantly, a detailed understanding of the behavior of amniotic fluid mesenchymal stromal cells and their osteogenic ability is desirable considering a feasible application in bone regenerative medicine.

Senescence and longevity in amniotic fluid derived cells

Amniotic fluid stem cells(AFSC) are noncontroversial and abundant potentially transplantable cells. They are derived from fetal and amniotic sources and show osteogenic, neuronal, and adipogenic differentiation in culture. Clinical material must be expanded in culture and sorted if clinical use is desired. Cellular senescence and replicative potential for AFSC cultures has had limited study, with scant data on gene expression over time. We report changes in samples from 17 patients over multiple passages form 10 to 81 population doublings. Longevity was unrelated to telomere length in these cells. It was related to upregulation of TWIST1, which is highly expressed in stem cells, and downregulation of genes associated with apoptosis.

Amniotic fluid stem cell-based models to study the effects of gene mutations and toxicants on male germ cell formation

Male infertility is a major public health issue predominantly caused by defects in germ cell development. In the past, studies on the genetic regulation of spermatogenesis as well as on negative environmental impacts have been hampered by the fact that human germ cell development is intractable to direct analysis in vivo. Compared with model organisms including mice, there are fundamental differences in the molecular processes of human germ cell development. Therefore, an in vitro model mimicking human sperm formation would be an extremely valuable research tool. In the recent past, both human embryonic stem （ES） cells and induced pluripotent stem （iPS） cells have been reported to harbour the potential to differentiate into primordial germ cells and gametes. We here discuss the possibility to use human amniotic fluid stem （AFS） ceils as a biological model. Since their discovery in 2003, AFS cells have been characterized to differentiate into cells of all three germ layers, to be genomically stable, to have a high proliferative potential and to be non-tumourigenic. In addition, AFS cells are not subject of ethical concerns. In contrast to iPS cells, AFSs cells do not need ectopic induction of pluripotency, which is often associated with only imperfectly cleared epigenetic memory of the source cells. Since AFS cells can be derived from amniocentesis with disease-causing mutations and can be transfected with high efficiency, they could be used in probing gene functions for spermatogenesis and in screening for male reproductive toxicity.

Human amniotic fluid stem cell therapy can help regain bladder function in type 2 diabetic rats

BACKGROUND Diabetes mellitus(DM)is a serious and growing global health burden.It is estimated that 80%of diabetic patients have micturition problems such as poor emptying,urinary incontinence,urgency,and urgency incontinence.Patients with diabetic bladder dysfunction are often resistant to currently available therapies.It is necessary to develop new and effective treatment methods.AIM To examine the therapeutic effect of human amniotic fluid stem cells(hAFSCs)therapy on bladder dysfunction in a type 2 diabetic rat model.METHODS Sixty female Sprague-Dawley rats were divided into five groups:Group 1,normal-diet control(control);group 2,high-fat diet(HFD);group 3,HFD plus streptozotocin-induced DM(DM);group 4,DM plus insulin treatment(DM+insulin);group 5,DM plus hAFSCs injection via tail vein(DM+hAFSCs).Conscious cystometric studies were done at 4 and 12 wk after insulin or hAFSCs treatment to measure peak voiding pressure,voided volume,intercontraction interval,bladder capacity,and residual volume.Immunoreactivities and/or mRNA expression of muscarinic receptors,nerve growth factor(NGF),and sensory nerve markers in the bladder and insulin,MafA,and pancreatic-duodenal homeobox-1(PDX-1)in pancreatic beta cells were studied.RESULTS Compared with DM rats,insulin but not hAFSCs treatment could reduce the bladder weight and improve the voided volume,intercontraction interval,bladder capacity,and residual volume(P<0.05).However,both insulin and hAFSCs treatment could help to regain the blood glucose and bladder functions to the levels near controls(P>0.05).The immunoreactivities and mRNA expression of M2-and M3-muscarinic receptors(M2 and M3)were increased mainly at 4 wk(P<0.05),while the number of beta cells in islets and the immunoreactivities and/or mRNA of NGF,calcitonin gene-related peptide(CGRP),substance P,insulin,MafA,and PDX-1 were decreased in DM rats(P<0.05).However,insulin and hAFSCs treatment could help to regain the expression of M2,M3,NGF,CGRP,substance P,MafA,and PDX-1 to near the levels of controls at 4 and/or 12 wk(P>0.05).CONCLUSION Insulin but not hAFSCs therapy can recover the bladder dysfunction caused by DM;however,hAFSCs and insulin therapy can help to regain bladder function to near the levels of control.

Identification of interleukin-6 (IL-6) and squamous cell carcinoma (SCC) as amniotic fluid-specific markers

Objective: To determine if an amniotic fluid (AF)-specific marker is present and if its concentration changes with the presence of labor. Study Design: Twenty-six healthy women who gave birth to healthy newborns at term during the period from July 2009 to January 2010 were included in the study. Six candidate markers were assessed by commercially available ELISA kits: interleukin (IL)-6, squamous cell carcinoma (SCC) antigen, insulin-like growth factor (IGFBP)-1, osteopontin (OPN), CA125, and sialyl Tn (STN). Results: The AF/maternal serum (MS) measurement based on IL-6 or SCC has proved to be superior to IGFBP-1, CA125, OPN and STN. Women with spontaneous labor at term had significantly higher IL-6 and IGFBP-1 concentrations in AF compared with those without labor. No significant differences were observed in the AF concentrations of SCC, OPN, CA125 and STN between women with labor and those not in labor. Conclusion: Our observation of IL-6 and SCC in AF may open a new area of research to assess their usefulness as biological markers of obstetrical disorders.

Amniotic fluid embolism:literature review and an integrated concept of pathomechanism

Literature concerning procoagulant activity of the amniotic fluid and pathomechanism of amniotic fluid embolism (AFE) was surveyed and a new concept of its pathogenesis, called the integrated concept of AFE, was presented. According to this concept, two components of the amniotic fluid are involved: (i) apoptosis-affected amniotic cells showing a special role in the initiation of disseminated intravascular coagulation (DIC) and (ii) leukotrienes (formerly called slow-reacting substances), inducing bronchial and pulmonary vascular smooth muscle contraction. Although each of these components initiates a different pathogenic pathway, they both lead to the formation of a mechanical barrier on blood flow through the lungs (amniotic debris + microemboli) and/or functional barrier (pulmonary vasoconstriction). An old dilemma, concerning indications for heparin therapy in AFE was recalled in the light of the new concept.

Secretion of nerve growth factor,brain-derived neurotrophic factor,and glial cell-line derived neurotrophic factor in co-culture of four cell types in cerebrospinal fluid-containing medium

The present study co-cultured human embryonic olfactory ensheathJng cells, human Schwann cells, human amniotic epithelial cells and human vascular endothelial cells in complete culture medium- containing cerebrospinal fluid. Enzyme linked immunosorbent assay was used to detect nerve growth factor, brain-derived neurotrophic factor, and glial cell line-derived neurotrophic factor secretion in the supernatant of co-cultured cells. Results showed that the number of all cell types reached a peak at 7-10 days, and the expression of nerve growth factor, brain-derived neurotrophic factor, and glial cell line-derived neurotrophic factor peaked at 9 days. Levels of secreted nerve growth factor were four-fold higher than brain-derived neurotrophic factor, which was three-fold higher than glial cell line-derived neurotrophic factor. Increasing concentrations of cerebrospinal fluid （10%, 20% and 30%） in the growth medium caused a decrease of neurotrophic factor secretion Results indicated co-culture of human embryonic olfactory ensheathing cells, human Schwann cells human amniotic epithelial cells and human vascular endothelial cells improved the expression of nerve growth factor, brain-derived neurotrophic factor, and glial cell line-derived neurotrophic factor. The reduction of cerebrospinal fluid extravasation at the transplant site after spinal cord injury is beneficial for the survival and secretion of neurotrophic factors from transplanted cells.

Applications of human amniotic fluid stem cells in wound healing

Complete wound regeneration preserves skin structure and physiological functions,including sensation and perception of stimuli,whereas incomplete wound regeneration results in fibrosis and scarring.Amniotic fluid stem cells(AFSCs)would be a kind of cell population with self-renewing and non-immunogenic ability that have a considerable role in wound generation.They are easy to harvest,culture,and store;moreover,they are non-tumorigenic and not subject to ethical restrictions.They can differentiate into different kinds of cells that replenish the skin,subcutaneous tissues,and accessory organs.Additionally,AFSCs independently produce paracrine effectors and secrete them in exosomes,thereby modulating local immune cell activity.They demonstrate anti-inflammatory and immunomodulatory properties,regulate the physicochemical microenvironment of the wound,and promote full wound regeneration.Thus,AFSCs are potential resources in stem cell therapy,especially in scar-free wound healing.This review describes the biological characteristics and clinical applications of AFSCs in treating wounds and provide new ideas for the treatment of wound healing.

不同胚层来源成体干细胞修复周围神经损伤

背景:成体干细胞疗法是周围神经损伤修复与再生领域的研究热点之一。中胚层被视为成体干细胞的理想来源,间充质干细胞具有获得率高、来源广、增殖快等优异性能。而外胚层来源成体干细胞,尤其是神经嵴干细胞,具有神经源性,越来越受到研究人员的关注。目的:对来自外胚层和中胚层的多功能成体干细胞在周围神经损伤修复与再生中的作用及机制进行简要综述,探究不同来源成体干细胞的研究进展与应用前景,并结合临床研究,探讨成体干细胞疗法潜在的应用价值以及亟待解决的问题。方法:第一作者于2024年2月应用计算机在PubMed和SinoMed数据库检索2001年12月至2024年2月相关文献,以“ectodermal stem cells,mesenchymal stem cells,peripheral nerve injury,repair,regeneration”为英文检索词,以“外胚层干细胞、间充质干细胞、周围神经损伤、修复、再生”为中文检索词,最终纳入69篇文献进行分析论述。结果与结论:①外胚层来源成体干细胞具有优异的分化和再生潜能,尤其是毛囊神经嵴干细胞、嗅干细胞、牙外胚层干细胞等,具有神经源性,可在体外表达神经特异性标志物,但目前缺少临床试验研究。②中胚层来源成体干细胞种类多、易获得及纯化,其中骨髓间充质干细胞和脐带间充质干细胞在周围神经损伤修复的应用疗效及安全性方面有相关临床试验支持,能改善感觉及运动神经传导,且在随访中未出现并发症和明显不良反应。骨髓间充质干细胞的获取需行侵入性外科手术且要求患者与捐赠者骨髓配型吻合,应用受到一定限制;而脐带间充质干细胞虽无需侵入性获取,但分离较困难且表型不稳定。③内胚层来源成体干细胞常难以在体外生长,应用受限,目前应用于临床的可能性低。④综合来看,骨髓间充质干细胞仍为周围神经损伤干细胞治疗的首选细胞,适用于无外科手术禁忌且符合配型要求的情况,其次为脐带间充质干细胞,辅以分离方法的改进和表型稳定性的提高策略。⑤牙外胚层干细胞以及脂肪间充质干细胞具有较高应用潜能,有待进一步临床试验,其他外胚层、中胚层来源成体干细胞各以其优异特性在动物及细胞实验研究中具有显著优势。

Stem cell therapy in inflammatory bowel disease: A promising therapeutic strategy?

Inflammatory bowel diseases are inflammatory, chronic and progressive diseases of the intestinal tract for which no curative treatment is available. Research in other fields with stem cells of different sources and with immunoregulatory cells(regulatory T-lymphocytes and dendritic T-cells) opens up new expectations for their use in these diseases. The goal for stem cell-based therapy is to provide a permanent cure. To achieve this, it will be necessary to obtain a cellular product, original or genetically modified, that has a high migration capacity and homes into the intestine, has high survival after transplantation, regulates the immune reaction while not being visible to the patient's immune system, and repairs the injured tissue.

Effect of intraoperative cell rescue on bleeding related indexes after cesarean section

BACKGROUND Obstetric hemorrhage is the leading cause of maternal mortality globally,especially in China.The key to a successful rescue is immediate and rapid blood transfusion.Autotransfusion has become an integral part of clinical blood transfusion,with intraoperative cell salvage(IOCS)being the most widely used.AIM To investigate the application of IOCS in cesarean section.METHODS A total of 87 patients who underwent cesarean section and blood transfusion in our hospital from March 2015 to June 2020 were included in this prospective controlled study.They were divided into the observation(43 cases)and control(44 cases)groups using the random number table method.The patients in both groups underwent lower-segment cesarean section.The patients in the control group were treated with traditional allogeneic blood transfusion,whereas those in the observation group were treated with IOCS.Hemorheology[Red blood cell count,platelet volume,and fibrinogen(FIB)]and coagulation function(partial prothrombin time,prothrombin time(PT),platelet count,and activated coagulation time)were measured before and 24 h after transfusion.In the two groups,adverse reactions,such as choking and dyspnea,within 2 h after cesarean section were observed.RESULTS Before and after transfusion,no significant differences in hemorheology and coagulation function indices between the two groups were observed(P>0.05).About 24 h after transfusion,the erythrocyte count,platelet ratio,and FIB value significantly decreased in the two groups(P<0.05);the PLT value significantly decreased in the two groups;the activated partial thromboplastin time,PT,and activated clotting time significantly increased in the two groups(P<0.05);and no statistical differences were observed in hemorheology and coagulation function indices between the two groups(P>0.05).Furthermore,there was no significant difference in the incidence of adverse reactions between the two groups(P>0.05).CONCLUSION In patients undergoing cesarean section,intraoperative cell salvage has a minimum effect on hemorheology and coagulation function and does not increase the risk of amniotic fluid embolism.

Prenatal diagnosis of Down syndrome using cell-free fetal DNA in amniotic fluid by quantitative fluorescent polymersase chain reaction

Backgroud Amniotic fluid （AF） supernatant contains cell-free fetal DNA （cffDNA） fragments.This study attempted to take advantage of cffDNA as a new material for prenatal diagnosis,which could be combined with simple quantitative fluorescent polymerase chain reaction （QF-PCR） to provide an ancillary method for the prenatal diagnosis of trisomy 21 syndrome.Methods AF supernatant samples were obtained from 27 women carrying euploid fetuses and 28 women carrying aneuploid fetuses with known cytogenetic karyotypes.Peripheral blood samples of the parents were collected at the same time.Short tandem repeat （STR） fragments on chromosome 21 were amplified by QF-PCR.Fetal condition and the parental source of the extra chromosome could be determined by the STR peaks.Results The sensitivity of the assay for the aneuploid was 93％ （26/28; confidence interval,CI：77％-98％） and the specificity was 100％ （26/26; CI：88％-100％）.The determination rate of the origin of the extra chromosome was 69％.The sensitivity and the specificity of the assay in the euploid were 100％ （27/27）.Conclusions Trisomy 21 can be prenatally diagnosed by the QF-PCR method in AF supernatant.This karyotype analysis method greatly reduces the requirement for the specimen size.It will be a benefit for early amniocentesis and could avoid pregnancy complications.The method may become an ancillary method for prenatal diagnosis of trisomy 21.

临床早期诊断羊水栓塞的进一步探讨

目的 :进一步探讨羊水栓塞 (AFE)的临床早期确诊。方法 :前瞻性地对 5例临床拟诊AFE者 ,取中心静脉血或外周血涂片 ,H E滴染 ;取同期 2 2例无心肺功能改变的足月孕妇及同期 4例死亡孕妇作对照组。结果 :5例拟诊羊水栓塞者 ,从作出临床诊断至发病的时间为 4～ 9小时 ,5例细胞学检查均找到角化与不全角化上皮细胞 ;对照组 2 2例孕妇中除 1例HELLP综合征的外周血涂片偶见角化上皮细胞外 ,余 2 1例及 4例死亡孕妇血中均未找到角化或不全角化上皮细胞。结论 :前瞻性地对有典型临床表现或疑诊AFE者进行细胞学检查是一种简单、迅速。

31例羊水染色体异常核型、B超检查和产后随访分析

目的 总结 31例异常羊水细胞染色体的核型、B超检查和产后随访情况 ,为今后产前诊断提供经验。方法 原位法培养羊水细胞并制备染色体 ,G显带分析核型 ;B超检查胎儿 ;用一般体格检查法进行产后随访。结果 31例中 2 1三体征 6例 ,1 8三体征 1例 ,部分 1 8三体征 1例 ,部分 1 1三体征 1例 ,易位 1 0例 ,倒位 8例 ,嵌合体 4例。在孕中期 ,B超发现 2 1三体征 2例、1 8三体征发育迟缓 2例、嵌合体核型 1例 ,此嵌合体核型胎儿外生殖器模糊。产后随访发现 1例嵌合体核型的胎儿外生殖器畸形 ,与B超诊断相符 ;1例嵌合体核型的胎儿为多发畸形 ,B超未能发现。 2例嵌合体核型的胎儿未见异常。结论 B超可做为检查胎儿染色体异常的辅助诊断。羊水细胞培养、制备染色体诊断嵌合体须慎重 ,且重复检查羊水染色体对确诊意义不大。

广州地区6000例羊水细胞染色体核型分析及其产前诊断价值探讨

目的分析羊水细胞染色体,比较不同异常核型的发生率及其在产前诊断中的应用价值。方法选择2010年1月至2013年9月到该院就诊有产前诊断指征的孕妇6 000例,行羊膜腔穿刺术、传代法羊水细胞培养及胎儿染色体核型分析。结果 6 000例羊水培养成功5 994例(99.90%),异常核型193例(3.22%)。其中,染色体数目异常108例,占异常核型的55.96%,以21三体为主,占数目异常的67.59%(73/108);结构异常60例,占异常核型的31.09%,其中平衡性结构重排38例(19.69%),非平衡性结构重排22例(11.40%);嵌合体25例(12.95%)。将孕妇按进行穿刺的首要指征分为6组,血清学筛查高风险组和高龄组分别占受检人数41.62%和33.70%,B超检查示胎儿异常组和夫妇一方染色体异常组的核型异常检出率分别为5.56%和20.00%,与其他组比较差异有统计学意义(P<0.05)。结论传代法羊水细胞体外培养对核型分析具有实用性。羊水染色体核型分析是安全、有效的诊断胎儿染色体病的方法。

染色体核型分析和荧光原位杂交技术用于产前诊断的价值

目的:应用染色体核型分析和荧光原位杂交(FISH)技术对2 708例孕妇的羊水细胞进行检测,探讨两种方法用于产前诊断的临床意义。方法:对2 708例有产前诊断指征的孕妇行羊膜腔穿刺术,获得羊水细胞分别进行细胞培养、染色体核型分析及FISH检测(FISH选取13、18、21、X、Y五条染色体特异性探针杂交)。结果:2 708例羊水细胞染色体核型分析培养失败3例,成功率99.9%。2 705例培养成功样本中检出染色体多态39例(1.4%);检出染色体异常核型105例(3.9%),其中染色体非整倍体异常82例,染色体结构异常23例。FISH检测成功率100%。共检出13、18、21、X、Y染色体非整倍体异常82例,性染色体嵌合2例,与染色体核型分析结果相符,1例嵌合型20号染色体三体未能检出,染色体结构异常及多态性均未检出。结论:染色体核型分析可检出全部染色体数目及结构异常,但对孕周要求较为严格、需要样本量大、诊断周期长、易培养失败、分辨率有限;FISH技术对孕周无严格要求,需要样本量小,可直接对未培养羊水细胞进行检测,快速、简便,但目前仅能检出有限的几条染色体数目异常,尚不能检出染色体平衡性结构改变如平衡易位、倒位、染色体多态等。

羊水细胞培养及染色体核型分析在产前诊断中的应用

目的探讨羊水细胞培养及染色体核型分析在产前诊断中的应用价值。方法从中孕期妇女羊膜腔穿刺获取羊水,细胞培养后分析染色体核型,进行产前诊断。结果 17例产前诊断患者羊水细胞培养及制片成功率均为100%,共检出异常染色体核型3例,检出率为17.65%,其中21三体2例(11.76%),胎儿2N/4N嵌合体1例(5.88%)。结论羊水细胞培养及染色体核型分析是目前安全、有效、可靠的产前诊断方法之一,结合唐氏筛查、超声诊断、脐血染色体检查可有效预防出生缺陷的发生。

羊水染色体制备技术的改进

目的改良羊水染色体制备技术。方法与传统羊水细胞染色体制备方法不同,在常规预固定加2次甲醇和冰醋酸3∶1(V∶V)固定基础上,新增1次甲醇和冰醋酸1∶3反比例固定操作,随机选取194个羊水标本制备染色体,比较新旧方法在制片成功率、染色体分散度和显带方面的差异。并应用改良方法对3 726例羊水标本进行核型分析。结果与传统方法相比,增加反固定方法不仅能显著提高羊水培养成功率(P<0.05),而且获得核型分散效果更好、染色体分辨率更高(P<0.05)。3 726例羊水标本中,一次性培养成功3 671例,成功率为98.52%,检出异常核型265例,异常率为7.22%。结论羊水染色体制备改良方法中增加反固定方法,所获核型好、成功率高,便于临床推广。