Human umbilical cord blood stem cells and brainderived neurotrophic factor for optic nerve injury: a biomechanical evaluation

Treatment for optic nerve injury by brain-derived neurotrophic factor or the transplantation of human umbilical cord blood stem cells has gained progress, but analysis by biomechanical indicators is rare. Rabbit models of optic nerve injury were established by a clamp. At 7 days after injury, the vitreous body received a one-time injection of 50 μg brain-derived neurotrophic factor or 1 × 10^6 human umbilical cord blood stem cells. After 30 days, the maximum load, maximum stress, maximum strain, elastic limit load, elastic limit stress, and elastic limit strain had clearly improved in rabbit models of optical nerve injury after treatment with brain-derived neurotrophic factor or human umbilical cord blood stem cells. The damage to the ultrastructure of the optic nerve had also been reduced. These findings suggest that human umbilical cord blood stem cells and brain-derived neurotrophic factor effectively repair the injured optical nerve, improve biomechanical properties, and contribute to the recovery after injury.

Human umbilical cord blood-derived stem cells and brain-derived neurotrophic factor protect injured optic nerve:viscoelasticity characterization

The optic nerve is a viscoelastic solid-like biomaterial.Its normal stress relaxation and creep properties enable the nerve to resist constant strain and protect it from injury.We hypothesized that stress relaxation and creep properties of the optic nerve change after injury.Moreover,human brain-derived neurotrophic factor or umbilical cord blood-derived stem cells may restore these changes to normal.To validate this hypothesis,a rabbit model of optic nerve injury was established using a clamp approach.At 7 days after injury,the vitreous body received a one-time injection of 50 μg human brain-derived neurotrophic factor or 1 × 106 human umbilical cord blood-derived stem cells.At 30 days after injury,stress relaxation and creep properties of the optic nerve that received treatment had recovered greatly,with pathological changes in the injured optic nerve also noticeably improved.These results suggest that human brain-derived neurotrophic factor or umbilical cord blood-derived stem cell intervention promotes viscoelasticity recovery of injured optic nerves,and thereby contributes to nerve recovery.

Noggin versus basic fibroblast growth factor on the differentiation of human embryonic stem cells

The difference between Noggin and basic fibroblast growth factor for the neural precursor differen- tiation from human embryonic stem cells has not been studied. In this study, 100 tJg/L Noggin or 20 IJg/L basic fibroblast growth factor in serum-free neural induction medium was used to differen- tiate human embryonic stem cells H14 into neural precursors using monolayer differentiation. Two weeks after induction, significantly higher numbers of neural rosettes formed in the Noggin-induced group than the basic fibroblast growth factor-induced group, as detected by phase contrast micro- scope. Immunofluorescence staining revealed expression levels of Nestin, [3-111 Tubulin and Sox-1 were higher in the induced cells and reverse-transcription PCR showed induced cells expressed Nestin, Sox-1 and Neurofilament mRNA. Protein and mRNA expression in the Noggin-induced group was increased compared with the basic fibroblast growth factor-induced group. Noggin has a greater effect than basic fibroblast growth factor on the induction of human embryonic stem cell differentiation into neural precursors by monolayer differentiation, as Noggin accelerates and in- creases the differentiation of neural precursors.

Human insulin-like growth factor 1-transfected umbilical cord blood neural stem cell transplantation improves hypoxic-ischemic brain injury

Human insulin-like growth factor 1-transfected umbilical cord blood neural stem cells were transplanted into a hypoxic-ischemic neonatal rat model via the tail vein. BrdU-positive cells at day 7 post-transplantation, as well as nestin- and neuron specific enolase-positive cells at day 14 were increased compared with those of the single neural stem cell transplantation group. In addition, the proportion of neuronal differentiation was enhanced. The genetically modified cell-transplanted rats exhibited enhanced performance in correctly crossing a Y-maze and climbing an angled slope compared with those of the single neural stem cell transplantation group. These results showed that human insulin-like growth factor 1-transfected neural stem cell transplantation promotes the recovery of the leaming, memory and motor functions in hypoxic-ischemic rats.

Chondrogenic differentiation of human bone mesenchymal stem cells treated with growth differentiation factor 5 under hypoxia

Objective To explore the feasibility and effectiveness of the self-assembly cartilage tissue engineered with chondrogenically differentiated human bone mesenchymal stem cells (hBMCs) induced by growth differentiation factor-5 (GDF-5)

Transplantation of human umbilical cord blood mesenchymal stem cells to treat a rat model of traumatic brain injury

In the present study, human umbilical cord blood mesenchymal stem cells were injected into a rat model of traumatic brain injury via the tail vein. Results showed that 5-bromodeoxyuridine-labeled cells aggregated around the injury site, surviving up to 4 weeks post-transplantation. In addition, transplantation-related death did not occur, and neurological functions significantly improved. Histological detection revealed attenuated pathological injury in rat brain tissues following human umbilical cord blood mesenchymal stem cell transplantation. In addition, the number of apoptotic cells decreased. Immunohistochemistry and in situ hybridization showed increased expression of brain-derived neurotrophic factor, nerve growth factor, basic fibroblast growth factor, and vascular endothelial growth factor, along with increased microvessel density in surrounding areas of brain injury. Results demonstrated migration of transplanted human umbilical cord blood mesenchymal stem cells into the lesioned boundary zone of rats, as well as increased angiogenesis and expression of related neurotrophic factors in the lesioned boundary zone.

HNF-4α determines hepatic differentiation of human mesenchymal stem cells from bone marrow

AIM: To investigate the differentiation status and key factors to facilitate hepatic differentiation of human bone-marrow-derived mesenchymal stem cells (MSCs). METHODS: Human MSCs derived from bone marrow were induced into hepatocyte-like cells following a previously published protocol. The differentiation status of the hepatocyte-like cells was compared with various human hepatoma cell lines. Overexpression of hepatocyte nuclear factor (HNF)-4α was mediated by adenovirus infection of these hepatocyte-like cells. The expression of interesting genes was then examined by either re-verse transcription-polymerase chain reaction (RT-PCR) or real-time RT-PCR methods. RESULTS: Our results demonstrated that the differentiation status of hepatocyte-like cells induced from human MSCs was relatively similar to poorly differentiated human hepatoma cell lines. Interestingly, the HNF-4 isoform in induced MSCs and poorly differentiated human hepatoma cell lines was identified as HNF4γ instead of HNF-4α. Overexpression of HNF-4α in induced MSCs significantly enhanced the expression level of hepatic-specific genes, liver-enriched transcription factors, and cytochrome P450 (P450) genes. CONCLUSION: Overexpression of HNF-4α improves the hepatic differentiation of human MSCs from bone marrow and is a simple way of providing better cell sources for clinical applications.

Hepatogenic differentiation of mesenchymal stem cells induced by insulin like growth factor-Ⅰ

AIM:To improve hepatic differentiation of human mesenchymal stem cell(MSC)using insulin growth factor 1(IGF-Ⅰ),which has important role in liver development,hepatocyte differentiation and function.METHODS:Bone marrow of healthy donors was aspirated from the iliac crest.The adherent cells expanded rapidly and were maintained with periodic passages until a relatively homogeneous population was established.The identification of these cells was carried out by immunophenotype analysis and differentiation potential into osteocytes and adipocytes.To effectively induce hepatic differentiation,we designed a protocol based on a combination of IGF-Ⅰ and liver specificfactors(hepatocyte growth factor,oncostatin M and dexamethasone).Morphological features,hepatic functions and cytological staining were assessed to evaluate transdifferentiation of human marrow-derived MSCs.RESULTS:Flow cytometric analysis and the differentiation potential into osteoblasts and adipocytes showed that more than 90% of human MSCs which were isolated and expanded were positive by specif ic markers and functional tests.Morphological assessment and evaluation of glycogen storage,albumin and α-feto protein expression,as well as albumin and urea secretion revealed a statistically signif icant difference between the experimental groups and control.CONCLUSION:In vitro differentiated MSCs using IGF-Ⅰwere able to display advanced liver metabolic functions,supporting the possibility of developing them as potential alternatives to primary hepatocytes.

Functional recovery and microenvironmental alterations in a rat model of spinal cord injury following human umbilical cord blood-derived mesenchymal stem cells transplantation

BACKGROUND： Transplantation of human umbilical cord blood-derived mesenchymal stem cells （MSCs） has been shown to benefit spinal cord injury （SCI） repair. However, mechanisms of microenvironmental regulation during differentiation of transplanted MSCs remain poorly understood. OBJECTIVE： To observe changes in nerve growth factor （NGF）, brain-derived neurotrophic factor （BDNF）, and interleukin-8 （IL-8） expression following transplantation of human umbilical cord-derived MSCs, and to explore the association between microenvironment and neural functional recovery following MSCs transplantation. DESIGN, TIME AND SETTING： A randomized, controlled, animal experiment was performed at the Department of Orthopedics, First Affiliated Hospital of Soochow University from April 2005 to March 2007. MATERIALS： Human cord blood samples were provided by the Department of Gynecology and Obstetrics, First Affiliated Hospital of Soochow University. Written informed consent was obtained. METHODS： A total of 62 Wister rats were randomly assigned to control （n = 18）, model （n = 22, SCI ＋ PBS）, and transplantation （n = 22, SCI ＋ MSCs） groups. The rat SCI model was established using the weight compression method. MSCs were isolated from human umbilical cord blood and cultured in vitro for several passages. 5-bromodeoxyuridine （BrdU）-Iabeled MSCs （24 hours before injection） were intravascularly transplanted. MAIN OUTCOME MEASURES： The rats were evaluated using the Basso, Beattie and Bresnahan （BBB） locomotor score and inclined plane tests. Transplanted cells were analyzed following immunohistochemistry. Enzyme-linked immunosorbant assay was performed to determine NGF, BDNF, and IL-8 levels prior to and after cell transplantation. RESULTS： A large number of BrdU-positive MSCs were observed in the SCI region of the transplantation group, and MSCs were evenly distributed in injured spinal cord tissue 1 week after transplantation. BBB score and inclined plane test results revealed significant functional improvement in the transplantation group compared to the model group （P 〈 0.05）, which was maintained for 2-3 weeks. Compared to the model group, NGF and BDNF levels were significantly increased in the injured region following MSCs transplantation at 3 weeks （P 〈 0.05）, but IL-8 levels remained unchanged （P 〉 0.05）. CONCLUSION： MSCs transplantation increased NGF and BDNF expression in injured spinal cord tissue. MSCs could promote neurological function recovery in SCI rats by upregulating NGF expression and improving regional microenvironments.

A comparative study on the transplantation of different concentrations of human umbilical mesenchymal cells into diabetic rats

AIM: To observe the effects of intravitreal injections of different concentrations of human umbilical mesenchymal stem cells on retinopathy in rats with diabetes mellitus.METHODS: Healthy and adult male Sprague-Dawley(SD) rats were randomly assigned to a normal control group(group A), a diabetic retinopathy(DR) blank control group(group B), a high-concentration transplantation group(group C), a low-concentration transplantation group(group D) and a placebo transplantation group(group E). The expression of nerve growth factor(NGF)protein in the retinal layers was detected by immunohistochemical staining at 2, 4, 6 and 8wk.RESULTS: The expression of NGF was positive in group A and most positive in the retinal ganglion cell layer. In groups B and E, the expression of NGF was positive 2wk after transplantation and showed an increase in all layers. However, the level of expression had decreased in all layers at 4wk and was significantly reduced at 8wk. In groups C and D, the expression of NGF had increased at 2wk and continued to increase up to 8wk. The level of expression in group C was much higher than that in group D.CONCLUSION: DR can be improved by intravitreal injection of human umbilical mesenchymal stem cells.High concentrations of human umbilical mesenchymal stem cells confer a better protective effect on DR than low concentrations.

Acetylcholine secretion by motor neuron-like cells from umbilical cord mesenchymal stem cells

Umbilical cord mesenchymal stem cells were isolated by a double enzyme digestion method. The third passage of umbilical cord mesenchymal stem cells was induced with heparin and/or basic fi- broblast growth factor. Results confirmed that cell morphology did not change after induction with basic fibroblast growth factor alone. However, neuronal morphology was visible, and micro- tubule-associated protein-2 expression and acetylcholine levels increased following induction with heparin alone or heparin combined with basic fibroblast growth factor. Hb9 and choline acetyl- transferase expression was high following inductive with heparin combined with basic fibroblast growth factor. Results indicate that the inductive effect of basic fibroblast growth factor alone was not obvious. Heparin combined with basic fibroblast growth factor noticeably promoted the differen- tiation of umbilical cord mesenchymal stem cells into motor neuron-like cells. Simultaneously, um- bilical cord mesenchymal stem cells could secrete acetylcholine.

Involvement of VLA-5 and VLA-6 in facilitating endothelium-oriented transmigration of hematopoietic stem/progenitor cells

目的 :研究 VLA- 5及 VLA- 6是否参与内皮细胞促进的造血干 /祖细胞定向移行。方法 :对纯化人 CD34+ 细胞进行体外移行及阻断实验 ,观察其穿移覆盖人脐静脉内皮细胞 ( HUVECs)滤膜的能力。应用四色荧光活化流式细胞术 ( FACS)检测 CD34+细胞其粘附分子及趋化因子受体CXCR- 4的表达谱。结果 :基质由来因子 ( SDF) - 1 α介导的动员外周血 ( m PB)及骨髓 ( BM)来源的CD34+ 细胞穿透覆盖 HUVECs滤膜百分率分别为 ( 5 6.6± 2 0 .1 ) %及 ( 1 5 .6± 1 .8) % ,显著高于其穿移未覆盖 HUVECs滤膜的比率。预先对 CD34+ 细胞进行抗 VLA- 5和 /或 VLA- 6中和抗体处理可消除这一促进效应。此外 ,BM来源的 CD34+细胞其穿移覆盖及未覆盖 HUVECs滤膜的能力均显著低于 m PB CD34+细胞 ,两者间穿移能力的差异与其 VLA- 5及 VLA- 6(而非 VLA- 4及趋化因子受体 CXCR- 4)抗原表达水平相关。结论 :VLA- 5和 VLA- 6参与 HUVECs促进 HS/PCs穿移能力。

巨噬细胞迁移抑制因子对人胚胎干细胞存活、增殖和分化的影响

背景:巨噬细胞迁移抑制因子(macrophage migration inhibitory factor,MIF)是一种具有多效性作用的细胞因子,可以在不同类型干细胞中自分泌并且能调控细胞的增殖、分化和迁移。课题组前期研究证实人胚胎干细胞自分泌MIF,且在培养液中浓度基本固定。然而,MIF是否参与了人胚胎干细胞的存活、增殖和分化尚不清楚。目的:探究MIF对人胚胎干细胞存活、增殖和分化的作用。方法:(1)培养人胚胎干细胞H9,CCK-8法检测并绘制细胞生长曲线,采用酶联免疫吸附法定量检测培养基中MIF水平。(2)为了明确外源性MIF对人胚胎干细胞存活、增殖的影响,分为:对照组,细胞在干细胞培养基中正常培养;外源性MIF组,在干细胞培养基中分别添加30,100,300 ng/m L的MIF;MIF抑制剂ISO-1组,在干细胞培养基中分别添加2,7,21μmol/L的ISO-1;MIF+ISO-1组,在不同浓度ISO-1组中分别添加100 ng/m L MIF,采用CCK-8法检测上述各组细胞活力。(3)为进一步阐明MIF基因对人胚胎干细胞存活、增殖的影响,采用CRISPRCas9技术构建MIF敲除的H9细胞系,观察建系情况。(4)为了明确高浓度MIF对人胚胎干细胞初步分化是否有影响,在培养基中分别添加100 ng/m L MIF和100 ng/m L CXCR4中和抗体,采用实时荧光定量聚合酶链式反应(RT-q PCR)、免疫细胞荧光、蛋白质印迹法(Western blot)检测干细胞自我更新因子(KLF4、c-MYC、NANOG、OCT4、SOX2)及分化转录因子(FOXA2、OTX2)的表达水平。结果与结论:(1)人胚胎干细胞H9的对数生长期为3-6 d,正常生长的情况下自分泌MIF水平约为20 ng/m L,与细胞量无关;(2)与对照组相比,添加不同质量浓度MIF对人胚胎干细胞的增殖无影响(P>0.05);ISO-1明显抑制人胚胎干细胞的增殖,ISO-1浓度越大,抑制越明显(P<0.05);ISO-1中添加MIF可以减少ISO-1的抑制作用(P<0.05);(3)RT-q PCR检测MIF基因敲除约50%后,人胚胎干细胞生长活力显著降低并且无法建系成功;(4)在培养基中添加100 ng/m L外源性MIF,自我更新转录因子KLF4的m RNA、蛋白及荧光表达水平均下降;分化因子FOXA2的m RNA、蛋白及荧光表达水平均上升;(5)在培养基中添加100 ng/m L CXCR4中和抗体,KLF4的m RNA及蛋白表达水平均上升;FOXA2的m RNA及蛋白表达水平均下降,与MIF组表达趋势相反。综上所述,人胚胎干细胞自分泌的MIF是其存活所必需的;培养基中额外添加MIF并不能促进人胚胎干细胞增殖,但可以使自我更新因子KLF4表达下降,转录因子FOXA2表达上升,为下一步探明MIF对人胚胎干细胞分化的影响及机制提供了线索,MIF-CXCR4轴在其中起到一定的调控作用。

Multiple cells of origin in cholangiocarcinoma underlie biological,epidemiological and clinical heterogeneity

Recent histological and molecular characterization of cholangiocarcinoma(CCA) highlights the heterogeneity of this cancer that may emerge at different sites of the biliary tree and with different macroscopic or morphological features.Furthermore,different stem cell niches have been recently described in the liver and biliarytree,suggesting this as the basis of the heterogeneity of intrahepatic(IH)-and extrahepatic(EH)-CCAs,which are two largely different tumors from both biological and epidemiological points of view.The complexity of the organization of the liver stem cell compartments could underlie the CCA clinical-pathological heterogeneity and the criticisms in classifying primitive liver tumors.These recent advances highlight a possible new classification of CCAs based on cells of origin and this responds to the need of generating homogenous diagnostic,prognostic and,hopefully,therapeutic categories of IH-and EH-CCAs.

影响肝硬化失代偿患者人脐带间充质干细胞治疗效果的影响因素探究

目的探讨多次进行人脐带间充质干细胞(human umbilical cord mesenchymal stem cells,HUC-MSCs)肝内移植及不同时间间隔治疗失代偿期肝硬化患者的临床疗效。方法选取河南科技大学第一附属医院2021年02月-2023年12月失代偿期肝硬化自愿接受治疗患者51例,随机分为单次移植组、多次移植组和对照组,各17例。对比三组实验室指标、影像学检查以及不良反应发生率。结果治疗前,三组肝功能及凝血功能指标差异均无统计学意义(P>0.05);治疗后,多次移植组谷丙转氨酶、总胆红素低于单次移植组与对照组,白蛋白水平高于单次移植组与对照组,差异有统计学意义(P<0.05);单次移植组白蛋白水平高于对照组,差异有统计学意义(P<0.05)。多次移植B组谷丙转氨酶、总胆红素低于A组,白蛋白高于A组,差异有统计学意义(P<0.05)。经影像学检查显示,多次移植组肝脏占位病变、门静脉血栓以及腹水发生率均低于单次移植组与对照组,差异有统计学意义(P<0.05);单次移植组肝脏占位病变、门静脉血栓以及腹水发生率低于对照组,但差异无统计学意义(P>0.05)。所有患者治疗过程中均未出现严重不良反应,仅多次移植组术后发生2例发热,经对症处理后消失。三组不良反应对比差异无统计学意义(P>0.05)。结论HUC-MSCs多次移植治疗肝硬化失代偿期患者具有良好的临床疗效,能够有效改善患者的肝脏功能,预防相关并发症的发生。同时,HUC-MSCs多次移植治疗的频率、间隔时间对疗效也有一定的影响,其中间隔3个月的疗效优于间隔1个月。

PEG-rhG-CSF在血液肿瘤自体造血干细胞动员中的临床分析

目的:探讨无外周血CD34监测下聚乙二醇重组人粒细胞集落刺激因子(PEG-rhG-CSF)在血液肿瘤自体外周血干细胞动员中的采集时机及采集效果。方法:回顾性分析2017年8月至2022年1月福建医科大学附属第一医院收治的46例行自体外周血干细胞动员的血液恶性肿瘤患者。采用大剂量化疗联合PEG-rhG-CSF或重组人粒细胞集落刺激因子(G-CSF)动员方案,其中应用PEG-rhG-CSF动员的27例(PEG-rhG-CSF组),应用G-CSF动员的19例(G-CSF组),比较两组患者动员采集效果。结果:46例患者共采集86例次,PEG-rhG-CSF组与G-CSF组获得采集物的单个核细胞中位数分别为6.54(3.85-12.61)×10^(8)/kg和6.15(1.13-11.58)×10^(8)/kg(P>0.05),采集物CD34^(+)细胞数分别为11.44(1.33-65.02)×10^(6)/kg和4.95(0.30-24.02)×10^(6)/kg(P<0.05),采集时机分别为14(10-20)和14(4-22)d(P>0.05)。PEG-rhG-CSF组在外周血白细胞(WBC)≥10×10^(9)/L时单次所采集的产物CD34^(+)细胞数明显高于外周血WBC<10×10^(9)/L时采集的数量[19.04(2.85-65.02)×10^(6)/kg vs 6.22(0.81-34.86)×10^(6)/kg,(P<0.05)]。结论:采用PEG-rhG-CSF动员外周血干细胞单次采集足量CD34^(+)细胞成功率高,中位动员时间为14 d;在无外周血CD34监测情况下,外周血WBC≥10×10^(9)/L可以考虑作为单次采集足量干细胞的采集阈值。

人胎盘间充质干细胞调控TGF-β1/Smad3信号通路抑制肺纤维化的发生

背景:研究表明人胎盘间充质干细胞能有效抑制肺纤维化的发展,但其发挥作用的具体机制目前并不清楚。目的:探究人胎盘间充质干细胞对二氧化硅诱导人胚肺成纤维细胞发生肺纤维化的治疗作用及相关机制。方法:CCK-8法检测不同质量浓度二氧化硅干预不同时间对MRC-5细胞增殖活力的影响,结合免疫荧光染色法筛选出最佳的二氧化硅刺激质量浓度与时间用于后续实验。将MRC-5细胞分为空白组、二氧化硅组、二氧化硅+人胎盘间充质干细胞组,空白组细胞不予任何处理,二氧化硅组MRC-5细胞给予100μg/mL二氧化硅刺激48 h,二氧化硅+人胎盘间充质干细胞组MRC-5细胞先给予100μg/mL二氧化硅刺激48 h后再与人胎盘间充质干细胞共培养24 h。免疫荧光染色检测各组细胞α-平滑肌肌动蛋白、胶原蛋白Ⅰ型蛋白的表达;Western blot检测各组细胞肺纤维化相关蛋白和TGF-β1/Smad 3信号通路相关蛋白表达。结果与结论:①CCK-8结果显示,100μg/mL二氧化硅刺激MRC-5细胞48 h为最佳质量浓度与时间;②免疫荧光染色结果显示,与二氧化硅组相比,二氧化硅+人胎盘间充质干细胞组α-平滑肌肌动蛋白、胶原蛋白Ⅰ型蛋白表达明显降低;③Western blot结果显示,与二氧化硅组相比,二氧化硅+人胎盘间充质干细胞组α-平滑肌肌动蛋白、胶原蛋白Ⅰ型、N-钙黏蛋白、粘连蛋白、转化生长因子β1、p-Smad3、Smad3的蛋白表达均降低,E-钙黏蛋白表达升高,差异均有显著性意义(P<0.05);④结果说明,人胎盘间充质干细胞能够对二氧化硅诱导的肺纤维化有显著的治疗作用;人胎盘间充质干细胞可以通过调控TGF-β1/Smad3信号通路抑制肺纤维化的发生。

高糖炎性环境下KLF4调控人牙周膜干细胞能量代谢的机制初探

目的:探究高糖炎性环境下Krüppel样因子4(KLF4)对人牙周膜干细胞(hPDLSCs)线粒体能量代谢和成骨分化的影响。方法:利用免疫荧光和Western blot实验研究高糖炎性环境下KLF4在hPDLSCs的定位和表达情况。通过碱性磷酸酶(ALP)和茜素红染色等检测高糖炎性环境下hPDLSCs成骨能力。通过慢病毒敲低和过表达技术,结合实时荧光定量PCR与Western blot实验检测病毒感染后KLF4的表达,检测KLF4对hPDLSCs成骨分化的影响。采用核酸酶靶向切割和释放(CUT&RUN)技术,分析高糖炎性环境下hPDLSCs中KLF4结合的DNA及相关信号通路变化。使用Seahorse能量代谢仪探索KLF4对hPDLSCs氧化呼吸能力的影响。结果:高糖炎性环境下,hPDLSCs中KLF4表达下调、ALP活性降低、钙结节形成减少(均P<0.001),Runt相关转录因子2(RUNX2)、骨钙素(OCN)表达降低(均P<0.001)。敲低KLF4,导致hPDLSCs的ALP活性降低(P<0.001),钙结节形成减少(P<0.001);过表达KLF4促进hPDLSCs的成骨分化。高糖炎性环境下,KLF4下游调控基因富集于能量代谢、成骨等相关通路。敲低KLF4导致hPDLSCs线粒体耗氧率(OCR)水平下调,而细胞外酸化率(ECAR)水平上调;过表达KLF4使OCR水平上调,而ECAR水平下调。结论:在高糖炎性环境下,hPDLSCs的成骨分化能力受损,KLF4可能通过上调线粒体氧化磷酸化能力来恢复hPDLSCs的成骨分化能力。

lncRNA TP53TG1在牙髓中的表达和对牙髓干细胞转录炎症因子的影响

目的探究lncRNA TP53TG1在健康和炎症牙髓中的表达差异,以及对脂多糖(LPS)诱导后人牙髓干细胞(hDPSCs)炎症因子转录水平的影响。方法设计合成lncRNA探针,利用RNA荧光原位杂交技术检测健康和炎症牙髓组织中lncRNA TP53TG1的表达情况。通过酶解组织块法分离培养hDPSCs,对培养的hDPSCs进行多向分化诱导验证,并通过流式细胞术鉴定表型特征。将hDPSCs分为si-NC组、si-NC+LPS组、si-TP53TG1+LPS组,分别转染对照序列和TP53TG1的siRNA,再用LPS处理si-NC+LPS组和si-TP53TG1+LPS组24 h,通过qRT-PCR检测各组炎症因子IL-1β、IL-8以及TNF-α的mRNA表达水平。结果在健康牙髓组织中可观察到lncRNA TP53TG1的表达,主要分布在成牙本质细胞中。炎症状态下,lncRNA TP53TG1的表达量上升,全牙髓可见分布。LPS处理后,hDPSC的TNF-α、IL-1β以及IL-8的mRNA表达水平上升,下调lncRNA TP53TG1导致hDPSCs的TNF-αmRNA表达水平进一步升高。结论lncRNA TP53TG1可能参与调控牙髓炎症过程和成牙本质细胞的免疫调控作用。

Epi-1对脂多糖诱导人牙髓干细胞炎症反应的影响

目的研究生物活性肽Epi-1在脂多糖(LPS)诱导下的炎症微环境中对人牙髓干细胞(hDPSC)表达炎症因子的影响和可能机制。方法通过组织块酶消化法分离、培养hDPSC,并通过流式细胞术鉴定。利用CCK-8试剂检测Epi-1对hDPSC细胞活性的影响,筛选出适宜的浓度。实验分为4组,分别为空白对照组(不含LPS和Epi-1)、LPS组(1.0μg/mL LPS)、2.5μg/mL Epi-1组(1.0μg/mL LPS和2.5μg/mL Epi-1)和5.0μg/mL Epi-1组(1.0μg/mL LPS和5.0μg/mL Epi-1),通过实时荧光定量聚合酶链式反应检测Epi-1对hDPSC白介素(IL)-6、IL-1β、IL-8基因表达的影响,进一步通过蛋白质免疫印迹法检测核因子κB信号通路关键蛋白p65、p-p65的表达情况,使用荧光探针检测活性氧生成情况。采用SPSS 22.0分析数据。结果在2.5、5.0μg/mL的质量浓度下,Epi-1无明显细胞毒性;Epi-1可显著降低LPS诱导后hDPSC中IL-6、IL-1β、IL-8的mRNA表达(P<0.01),减少p-p65的表达(P<0.05)和活性氧的生成(P<0.001)。结论Epi-1可能通过抑制核因子κB信号通路的激活和减轻氧化应激反应,从而降低LPS诱导的hDPSC的炎症反应。