Senescent mesenchymal stem/stromal cells in pre-metastatic bone marrow of untreated advanced breast cancer patients

Breast cancer is the predominant form of carcinoma among women worldwide,with 70%of advanced patients developing bone metastases,with a high mortality rate.In this sense,the bone marrow(BM)mesenchymal stem/stromal cells(MSCs)are critical for BM/bone homeostasis,and failures in their functionality,transform the BM into a premetastatic niche(PMN).We previously found that BM-MSCs from advanced breast cancer patients(BCPs,infiltrative ductal carcinoma,stage III-B)have an abnormal profile.This work aims to study some of the metabolic and molecular mechanisms underlying MSCs shift from a normal to an abnormal profile in this group of patients.A comparative analysis was undertaken,which included self-renewal capacity,morphology,proliferation capacity,cell cycle,reactive oxygen species(ROS)levels,and senescence-associatedβ‑galactosidase(SA‑β‑gal)staining of BMderived MSCs isolated from 14 BCPs and 9 healthy volunteers(HVs).Additionally,the expression and activity of the telomerase subunit TERT,as well as telomere length,were measured.Expression levels of pluripotency,osteogenic,and osteoclastogenic genes(OCT-4,SOX-2,M-CAM,RUNX-2,BMP-2,CCL-2,M-CSF,and IL-6)were also determined.The results showed that MSCs from BCPs had reduced,self-renewal and proliferation capacity.These cells also exhibited inhibited cell cycle progression and phenotypic changes,such as an enlarged and flattened appearance.Additionally,there was an increase in ROS and senescence levels and a decrease in the functional capacity of TERT to preserve telomere length.We also found an increase in pro-inflammatory/pro-osteoclastogenic gene expression and a decrease in pluripotency gene expression.We conclude that these changes could be responsible for the abnormal functional profile that MSCs show in this group of patients.

Bone marrow mesenchymal stem cell transplantation retards the natural senescence of rat hearts

Aim Aging is an independent risk factor for heart disease, however the effective intervention has not been found so far. Bone marrow mesenchymal stem cells （BMSCs） have been shown to offer a wide variety of cel- lular functions including the protective effects on damaged hearts. Here we investigated the antiaging properties of BMSCs and the underlying mechanism in a cellular model of cardiomyocyte senescence and a rat model of aging hearts. Methods In vitro study, neonatal rat ventricular cells （NRVCs） and BMSCs were cocultured in the same dish with a semipermeable membrane to separate the two populations. In vivo, the BMSCs were injected into the rat hearts to observe their antiaging effects. The expression of β-galactosidase and aging-related proteins, and the lev- els of oxidative stress were determined in vivo and in vitro. The heart function was measured by the High-Resolution Imaging System. Results Monocultured NRVCs displayed the senescence-associated phenotypes, characterized by an increase in the number of β-galaetosidase-positive cells and decreases in the degradation and disappearance of cellular organelles in a time-dependent manner. The levels of reactive oxygen species and malondialdehyde were el- evated, whereas the activities of antioxidant enzymes superoxide dismutase and glutathione peroxidase were de- creased, along with upregulation of p53, p21cipl/wafl and p16INK4a in the aging eardiomyoeytes. These deleterious alterations were abrogated in aging NRVCs cocultured with BMSCs. Qualitatively, the same senescent phenotypes were consistently observed in aging rat hearts. Notably, BMSC transplantation significantly prevented these detri- mental alterations and improved the impaired cardiac function in the aging rats. Conclusions BMSCs possess strong antiseneseence action on the aging NRVCs and hearts and can improve cardiac function after transplantation in aging rats. The present study, therefore, provides an alternative approach for the treatment of heart failure in the elderly population.

Intravenous transplantation of bone marrow mesenchymal stem cells promotes neural regeneration after traumatic brain injury

To investigate the supplement of lost nerve cells in rats with traumatic brain injury by intravenous administration of allogenic bone marrow mesenchymal stem cells, this study established a Wistar rat model of traumatic brain injury by weight drop impact acceleration method and administered 3 × 106 rat bone marrow mesenchymal stem cells via the lateral tail vein. At 14 days after cell transplantation, bone marrow mesenchymal stem cells differentiated into neurons and astrocytes in injured rat cerebral cortex and rat neurological function was improved significantly. These findings suggest that intravenously administered bone marrow mesenchymal stem cells can promote nerve cell regeneration in injured cerebral cortex, which supplement the lost nerve cells.

The effect of neuropeptides on proliferation of rat bone marrow mesenchymal stem cells

Objective To investigate the effects and mechanism of calcitonin gene-related peptide(CGRP)and substance P (SP) on proliferation of rat bone marrow mesenchymal stem cells.Methods The rBMSCs were isolated using whole bone marrow

Improvement of neurological function in rats with spinal cord injury after the transplantation of neural stem cells directly differentiated from bone marrow mesenchymal stem cells

Objective To study the effect and mechanism of neurological function recovery in rats with spinal cord injury ( SCI) rats after transplantation of neural stem cells which are directly differentiated from bone marrow mesenchymal stem cells ( BMSC ) ,and to investigate the suitable engraftment time. Methods BMSC at 3rd passage were differentiated into neural stem cells ( NSC) , and immunofluorescence staining was used to

Conditions to improve expansion of human mesenchymal stem cells based on rat samples

AIM: To improve the isolation and expansion of human marrow-derived mesenchymal stem cells (MSCs) based on rat samples. METHODS: Based on the fact that rat MSCs are relatively easy to obtain from a small aspirate, bone marrow-derived MSCs from rat were cultured and characterized to set up the different protocols used in this study. Then, accordingly, almost the same protocols were performed on human healthy bone marrow samples, after obtaining approval of the ethics committee and gaining informed consent. We used different protocols and culture conditions, including the type of basal media and the culture composition. The MSCs were characterized by immunophenotyping and differentiation. RESULTS: There was no difference in morphology and proliferation capacity between different culture media at the first passage. During the 5-7th passages, the cells gradually lost their morphology and proliferation potential on Dulbecco’s modified Eagle’s medium (DMEM) high glucose and α modified Eagle’s medium. Although the cells expanded rapidly for up to 10 passages on DMEM low glucose containing 10% to 15% fetal calf serum (FCS), their proliferation was arrested without change in morphology and differentiation capacity at the third passage on 5% FCS. Flow cytometric analysis and functional tests confirmed that more than 90% of marrow cells which were isolated and expanded by our selective protocols were MSCs. CONCLUSION: We improved the isolation and expansion of human bone marrow derived MSCs, based on rat sample experiments, for further experimental and clinical use.

Cell multiplication, apoptosis and p-Akt protein expression of bone mesenchymal stem cells of rat under hypoxia environment

Objective ：To elucidate whether cell multiplication, apoptosis, glucose intake and p-Akt protein expression of bone Mesenchyreal Stem Cells（MSCs） of rats is influenced by a hypoxic environment ex vivo. Methods ：Passage 3 of bone marrow MSCs taken from Wistar rats,were cultured in a culturing chamber with 94%N2,1%O2,5%CO2 at 37℃. At different hypoxia time points ,0,0.5, 1,4 and 8 h, glucose uptake was assayed by using radiation isotope ^3H-G, Apoptotic Rate（AR） and dead rate（DR） were analyzed by flow cytometry（FCM） after Annexin V/PI staining, cell multiplication（by MTr methods） and p-Akt protein by immunocytochemistry and western blot. Results ：Assay for CD29^± ,CD44^± ,CD71^± ,CD34^-, Tn T^±（after 5-azacytidine agent inducing） and ALP^±（after bone differentiation agent inducing） suggested these bone-derived cells were MSCs. The ^3H-G intaking ratio （CPM/ flask value：157 ± 11,110 ± 11,107 ± 13,103 ± 10,100 ± 9 and 98 ± 10） of MSCs at different hypoxia time points, significantly decreased compared to that of normoxia（P 〈 0.01） and tended to descend slowly with hypoxia time duration, for which there was no statistical significance（P 〉 0.05）. The AR（0.09 ± 2.03%,12.9 ± 1.72%,13.7 ± 2.26%,13.8 ± 3.01%,14.1 ± 2.78% and 14.7 ± 4.01% at 0,0.5,1,4 and 8 h,respectively,P 〈 0.01） and DR （0.04, ± 1.79% ,0.93 ± 1.85% ,3.11 ± 2.14% ,4.09 ± 2.36% ,4.72 ± 2.05% and 4.91 ± 3.72% at 0,0.5,1,4 and 8 h, respectively, P 〈 0.05） at different hypoxia time points significantly increased compared to those time in normoxia; The AR further went up with time （P 〈 0.05）, however there was no statistical significance （P 〉 0.05） for the DR. Optical absorption value of MTr methods at different hypoxia time points significantly decreased compared to those with a corresponding normoxia time （P 〈 0.01） and degraded with time （in an hypoxic environment -P 〈 0.01）. IOD of p-Akt protein of MSCs at different hypoxia time points significantly increased （0.367 ± 0.031,0.556 ± 0.023,0.579 ± 0.013, 0.660 ± 0.024, 0.685 ± 0.039 and 0.685 ± 0.011, respectively） compared to their equivalents in normoxia （P〈0.05）, however, there was no statistical significance （P 〉 0.05） for different hypoxia time points. Hypoxia may result in ultramicrostructure changes, such as defluvium of Microvilli, apoptotic body, ＂margination＂ and so on and are further aggravated with hypoxia time stretching. Conclusion： Hypoxia may lead to a depression of MSCs intaldng glucose, creep of cell multiplication, upregulation of p-Akt protein and apoptosis of MSCs ex vivo.

Therapeutic Potential of Bone Marrow Derived Mesenchymal Stem Cells in Modulating Astroglyosis of Surgical Induced Experimental Spinal Cord Injury

Background: Spinal cord injury (SCI) unsuccessful regeneration was due to glial scar development. It was a major obstacle to axonal restoration. Safe therapeutic intervention by the use of bone marrow derived stem cells (BMMSCs) transplantation applied in the present study could reduce spinal disability. Material and methods: Forty male albino rats were divided into four groups: GI: negative control (n = 10 rats);GII: positive control after SCI (n = 10 rats);GIII: SCI + BM - MSCs intravenous injected and GIV: SCI + BM - MSCs intra lesion injected (n = 10 rats in each group). The samples were taken from spinal cord tissues around the region of injury and were subjected to histological, immunohistochemical assessment. RNA extraction and real time PCR for detection of nerve regeneration and astrocyte response to the injury were also performed. Results: Clinical improvement occurred by the enhancement in the Basso, Beattie and Bresnahan (BBB) score after SCI. Histological examinations showed positive regenerative responses in GIV compared to GIII. Conclusion: BM-MSCs transplantation has a promising role in enhancing the microenvironment for nerve regeneration through stumbling the glial scaring formation and inflammatory response after chronic spinal cord injury especially by using intra-lesion route injection.

Effect of SHU555A labeling on differentiation of bone marrow mesenchymal stem cells into neurocyte-like cells

Objective:To investigate the effect of SHU555A,a clinically approved iron nanoparticle,labeling on differentiation of bone marrow mesenchymal stem cells(BMSCs) into neurocyte-like cells in vitro.Methods:10 times dilution of 10μl,20μl,40μl and 80μl SHU555A were added to 2ml of culture medium containing rat BMSCs to obtain four experimental groups of SHU555A labeling of BMSCs with ferri ion concentrations of 14μg/ml,28μg/ml,56μg/ml and 112μg/ml,respectively.2ml of culture medium with rat BMSCs did not contain SHU555A served as control group.The BMSCs of all the groups were pre-induced by bFGF,and induced by DMSO/butylated hydroxyanisole(BHA) for six hours,subsequently reverse transcription polymerase chain reaction(RT-PCR) technique was employed to detect mRNA expression of nestin,neuronspecific analase(NSE) and glial fibrillary acid protein(GFAP).Western blot technique was used to detectprotein expression of nestin.Results:Quantitative-PCR revealed high mRNA expression of nestin,NSE and GFAP induced by DMSO/BHA in all the experimental groups,but the difference between the experimental groups and the control group was not significant(P>0.05).Western blot analysis demonstrated there was no statistically significant difference in nestin protein expression between the experimental groups and the control group(P>0.05).Conclusion:SHU555A labeling do not affect differentiation of rat BMSCs into neurocyte-like cells in vitro.

The effect of bone marrow mesenchymal stem cell transplantation on hypoxic pulmonary hypertension in rats

Objective:To study the influence of bone marrow mesenchymal stem cells(MSCs)transplantation on hypoxic pulmonary hypertension(HPH)in rats.Methods:MSCs in SD rats were separated,cultivated,identified in vitro,and labeled by the green fluorescence protein(GFP)adenovirus.Healthy male SD rats were randomly divided into four groups:normal control group(NC group)and HPH group,with eight rats in each group respectively;HPH+mesenchymal stem cell transplantation group(MSCs group)and HPH+vascular endothelial growth factor+mesenchymal stem cell transplantation group(VEGF+MSCs group),with twenty-four rats in each group respectively.In this experiment,intermittent normobaric hypoxia was employed to establish the pulmonary hypertension rat models,with stem cells transfected and transplanted.The mean pulmonary artery pressure(mPAP)was observed in rats to calculate the right ventricular hypertrophy index(RVHI);the morphological changes of pulmonary arterioles in each group of rats were observed under the microscope;the distribution and manifestation of MSCs fluorescently labeled by adenovirus transfection were observed in pulmonary arterioles under the fluorescence microscope at the set time points of 7 d,14 d and 28 d after the transplantation of stem cells.Results:For NC group,the mPAP(mmHg)was 15.5±1.5 at 28 d,while the mPAP in HPH,MSCs and VEGF+MSCs groups were 26.1±1.9,21.6±2.7 and 20.1±2.9 respectively which were apparently higher than that in NC group(p<.01).Compared with HPH group(p<.01),the mPAP was obviously decreased in MSCs and VEGF+MSCs groups.There was no significant difference between MSCs and VEGF+MSCs groups.At 28 d,RVHI for NC group was 0.28±0.02,while the RVHI in HPH,MSCs and VEGF+MSCs groups were 0.43±0.07,0.34±0.03 and 0.35±0.01 respectively which were apparently higher than that in NC group(p<.01).In comparison with HPH group,RVHI was significantly decreased in MSCs and VEGF+MSCs groups(p<.05).There was no significant difference between MSCs and VEGF+MSCs groups.For HPH group,at 28 d,pulmonary arterioles were apparently thickened,with luminal stenosis&obliteration and incomplete endothelial cells.Compared with HPH group,pulmonary arterioles in MSCs group became thinning,with the lumen unobstructed and the integrity of endothelial cells improved.The changes in the manifestation of MSCs and VEGF+MSCs groups were not significant.Conclusions:The transplantation of MSCs can improve the remodeling of pulmonary arterioles to partially reverse the progress of HPH;the combined transplantation of VEGF and MSCs doesn’t improve the effect of MSC transplantation.

Transplantation of Nogo-66 receptor gene-silenced cells in a poly(D,L-lactic-co-glycolic acid) scaffold for the treatment of spinal cord injury

Inhibition of neurite growth, which is in large part mediated by the Nogo-66 receptor, affects neural regeneration following bone marrow mesenchymal stem cell transplantation. The tissue engineering scaffold poly（D,L-lactide-co-glycolic acid） has good histocompatibility and can promote the growth of regenerating nerve fibers. The present study used small interfering RNA to silence Nogo-66 receptor gene expression in bone marrow mesenchymal stem cells and Schwann cells, which were subsequently transplanted with poly（D,L-lactide-co-glycolic acid） into the spinal cord lesion regions in rats. Simultaneously, rats treated with scaffold only were taken as the control group. Hematoxylin-eosin staining and immunohistochemistry revealed that at 4 weeks after transplantation, rats had good motor function of the hind limb after treatment with Nogo-66 receptor gene-silenced ceils prus the poly（O,L-lactide-co-glycolic acid） scaffold compared with rats treated with scaffold only, and the number of bone marrow mesenchymal stem cells and neuron-like cells was also increased. At 8 weeks after transplantation, horseradish peroxidase tracing and transmission electron microscopy showed a large number of unmyelinated and myelinated nerve fibers, as well as intact regenerating axonal myelin sheath following spinal cord hemisection injury. These experimental findings indicate that transplantation of Nogo-66 receptor gene-silenced bone marrow mesenchymal stem cells and Schwann cells plus a poly（D,L-lactide-co-glycolic acid） scaffold can significantly enhance axonal regeneration of spinal cord neurons and improve motor function of the extremities in rats following spinal cord injury.

Human adipose-derived mesenchymal stem cells： a better cell source for nervous system regeneration

Background In order to suggest an ideal source of adult stem cells for the treatment of nervous system diseases,MSCs from human adipose tissue and bone marrow were isolated and studied to explore the differences with regard to cell morphology,surface markers,neuronal differentiation capacity,especially the synapse structure formation and the secretion of neurotrophic factors.Methods The neuronal differentiation capacity of human mesenchymal stem cells from adipose tissue （hADSCs） and bone marrow （hBMSCs） was determined based on nissl body and synapse structure formation,and neural factor secretion function.hADSCs and hBMSCs were isolated and differentiated into neuron-like cells with rat brain-conditioned medium,a potentially rich source of neuronal differentiation promoting signals.Specific neuronal proteins and neural factors were detected by immunohistochemistry and enzyme-linked immunosorbent assay analysis,respectively.Results Flow cytometric analysis showed that both cell types had similar phenotypes.Cell growth curves showed that hADSCs proliferated more quickly than hBMSCs.Both kinds of cells were capable of osteogenic and adipogenic differentiation.The morphology of hADSCs and hBMSCs changed during neuronal differentiation and displayed neuronlike cell appearance after 14 days＇ differentiation.Both hADSCs and hBMSCs were able to differentiate into neuron-like cells based on their production of neuron specific proteins including β-tubulin-Ⅲ,neuron-specific enolase （NSE）,nissl bodies,and their ability to secrete brain derived neurotrophic factor （BDNF） and nerve growth factor （NGF）.Assessment of synaptop hysin and growth-associated protein-43 （GAP-43） suggested synapse structure formation in differentiated hADSCs and hBMSCs.Conclusions Our results demonstrate that hADSCs have neuronal differentiation potential similar to hBMSC,but with a higher proliferation capacity than hBMSC.Adipose tissue is abundant,easily available and would be a potential ideal source of adult stem cells for neural-related clinical research and application.

Differentiation of marrow-derived islet-like cells and their effects on diabetic rats

In recent years, islet transplantation for diabetes has shown signs of the treatment efficacy, but its application is limited due to lack of donor organizations, sources and immune rejection. Bone marrow mesenchymal stem cells （BMSCs） have become a new resource of islet cell substitutes. One focus of the current research is the application of a specific inducing agent or a culture system to get directed differentiation of BMSCs, which may have part characteristics of islet cells and then be used in autologous transplantation for the treatment of diabetes.

BM-MSCs延缓CD8^(+)初始T细胞衰老

目的验证骨髓间充质干细胞(BM-MSCs)缓解免疫衰老的作用,探究其衰老改善的主要免疫细胞群体。方法分离获得小鼠脾淋巴细胞,刺激增殖7d构建复制性衰老细胞模型。利用流式细胞测量术检测年轻对照组、复制性衰老对照组和BM-MSCs共培养组T细胞亚群衰老标志物p16ink4a(p16)和p21cip1(p21)的表达水平。结果T淋巴细胞复制性衰老模型中观察到持续增殖后CD8^(+)T细胞较CD4^(+)T细胞衰老显著,在CD8^(+)T细胞的初始细胞、效应细胞亚群中,效应细胞衰老最显著;BM-MSCs共培养对衰老的效应细胞没有明显影响,主要通过延缓初始T细胞的衰老,达到缓解CD8^(+)T细胞衰老的作用(P<0.01,P<0.001)。结论与BM-MSCs共培养可以缓解T细胞的复制性衰老表型,对CD8^(+)T细胞的抗衰作用更显著,主要通过抑制初始T细胞的衰老实现。

外源性硫化氢通过Wnt/β-catenin信号通路促进衰老BMSCs的成骨分化

目的:探讨外源性硫化氢供体GYY4137对D-半乳糖(D-Gal)诱导的衰老骨髓间充质干细胞(bone marrow mesenchymal stem cells,BMSCs)成骨能力的影响及潜在机制。方法:应用不同浓度的D-Gal诱导BMSCs的衰老,CCK8法检测细胞活性及β-半乳糖苷酶染色检测细胞衰老的程度,确定D-Gal的最佳诱导浓度;应用不同浓度GYY4137进行干预后,检测GYY4137对正常BMSCs及衰老BMSCs细胞活性的影响,确定GYY4137最佳干预浓度。实验设CON组、GYY4137组、D-Gal组、D-Gal+GYY4137组,作相应处理后对各组BMSCs进行β-半乳糖苷酶染色,qRT-PCR法检测衰老相关基因(P16、P21、P53)和衰老相关炎症因子(IL-6、IL-8、TNF-α)的mRNA相对表达。对各组细胞进行成骨诱导分化,qRT-PCR法检测成骨分化相关因子碱性磷酸酶(ALP)、骨钙素(OCN)、Runt相关转录因子2(RUNX2)、人骨形态发生蛋白2(BMP2)的mRNA表达,通过茜素红染色法检测钙结节形成数量,ALP染色法检测ALP的生成。通过转录组测序检测D-Gal组、D-Gal+GYY4137组两组细胞的差异表达基因,根据测序结果,qRT-PCR对差异基因进行验证。应用Dickkopf相关蛋白1(dickkopf Wnt signaling pathway inhibitor 1,DKK1)抑制Wnt10b的表达后,检测各组衰老BMSCs的成骨分化能力。结果:D-Gal的最佳诱导浓度为30 g/L,GYY4137的最佳干预浓度为10μmol/L,D-Gal组β-半乳糖苷酶阳性细胞比例显著增加,衰老相关基因(P16、P21、P53)及衰老相关炎症因子(IL-6、IL-8、TNF-α)mRNA的表达量显著升高(P<0.05或P<0.01),应用GYY4137干预后,以上细胞衰老相关指标显著降低(P<0.05或P<0.01)。在成骨分化过程中,D-Gal+GYY4137组ALP、OCN、RUNX2、BMP2的mRNA表达,钙结节阳性比例显著高于D-Gal组(P<0.05或P<0.01);测序结果发现Wnt/β-catenin信号通路中的Wnt10b表达有显著差异,qRT-PCR结果显示GYY4137可增加衰老细胞Wnt10b及其下游基因β-catenin的表达(P<0.05或P<0.01),与测序结果一致。应用100μg/L DKK1抑制Wnt10b的表达后,GYY4137处理的衰老BMSCs成骨分化相关基因ALP、OCN、RUNX2、BMP2的mRNA表达明显降低(P<0.05或P<0.01)。结论:GYY4137可以缓解D-Gal诱导的BMSCs衰老进程,并且可能通过Wnt/β-cantenin信号通路促进衰老BMSCs的成骨分化。

白藜芦醇对人骨髓间充质干细胞自发衰老的抑制作用

目的:观察白藜芦醇(RSV)对人骨髓间充质干细胞(MSC)的自发衰老是否具有抑制作用。方法:将MSC传至p13和p15代,建立MSC的自发衰老模型组;用5 nmol/L RSV分别处理p13和p15代MSC 48 h,建立RSV处理组。通过SA-β-Gal染色法检测细胞衰老,MTT法检测细胞增殖,RT-PCR检测细胞衰老相关端粒酶活性,Western blot检测与衰老相关的磷酸化mTOR的水平。结果:SA-β-Gal染色显示,RSV处理组MSC的衰老细胞数量明显少于模型组(p13代MSC,RSV组vs模型组,P<0.05;p15代MSC,RSV组vs模型组,P<0.01)。MTT结果显示,RSV处理组MSC的增殖能力高于模型组,其中p13代MSC处理组与模型组在72 h相比有显著差异(P<0.05)。RT-PCR结果显示,RSV处理组中MSC的hTERT mRNA表达量高于模型组,其中p13代MSC的RSV处理组与模型组相比有显著差异(P<0.05)。Western blot结果显示,RSV处理组中MSC的磷酸化(Ser2448)mTOR水平低于模型组,其中p13代MSC的处理组与模型组相比有显著差异(P<0.05)。结论:RSV可通过调节mTOR活性抑制人MSC的自发衰老。

miR-212-3p靶向MAPK3调控骨髓间充质干细胞的衰老

背景:骨质疏松症患者的骨髓间充质干细胞表现出明显衰老状态,并且细胞活性及成骨分化水平显著降低。miR-212-3p能够抑制人骨髓间充质干细胞的成骨分化,但其对骨髓间充质干细胞衰老调控的作用及机制尚不明确。目的:研究miR-212-3p通过靶向丝裂原活化蛋白激酶3(mitogen-activated protein kinase 3,MAPK3)对骨髓间充质干细胞衰老的影响及其机制。方法:体外分离培养大鼠骨髓间充质干细胞,收集第3代进行以下实验:①分2组培养:对照组加入完全培养基,造模组加入含H_(2)O_(2)的完全培养基培养,培养72 h后,检测细胞中β-半乳糖苷酶活性、miR-212-3p和MAPK3 mRNA表达,以及MAPK3、p16和p21蛋白表达。②分3组培养:对照组、抑制物对照组、miR-212-3p抑制物组,转染24 h后,检测细胞中miR-212-3p、MAPK3 mRNA表达及MAPK3蛋白表达。③采用双荧光素酶报告基因联合qRT-PCR和Western blot验证miR-212-3p与MAPK3靶向调控作用。④分组培养:分为对照抑制物组、miR-212-3p抑制物组、miR-212-3p抑制物+干扰对照组、miR-212-3p抑制物+MAPK3干扰组,转染24 h后,检测细胞中MAPK蛋白与mRNA表达。分为对照组、H_(2)O_(2)组、H_(2)O_(2)+对照抑制物组、H_(2)O_(2)+miR-212-3p抑制物组、H_(2)O_(2)+miR-212-3p抑制物+干扰对照组、H_(2)O_(2)+miR-212-3p抑制物+MAPK3干扰组,细胞转染24 h后再加入H_(2)O_(2)培养72 h,检测细胞中衰老相关β-半乳糖苷酶活性、p16和p21蛋白表达。结果与结论:①与对照组比较,造模组β-半乳糖苷酶活性、miR-212-3p mRNA表达及p16、p21蛋白表达升高(P<0.05),MAPK3 mRNA和蛋白表达降低(P<0.05)。②与对照组比较,miR-212-3p抑制物组细胞中miR-212-3p mRNA表达降低(P<0.05),MAPK3 mRNA与蛋白表达升高(P<0.05)。③双荧光素酶报告基因实验证实,MAPK3是miR-212-3p下游靶基因。④与对照抑制物组比较,miR-212-3p抑制物组细胞中MAPK3 mRNA和蛋白表达升高(P<0.05);与miR-212-3p抑制物组比较,miR-212-3p抑制物+MAPK3干扰组细胞中MAPK3 mRNA和蛋白表达降低(P<0.05)。与H_(2)O_(2)+对照抑制物组比较,H_(2)O_(2)+miR-212-3p抑制物组β-半乳糖苷酶活性降低(P<0.05);与H_(2)O_(2)+miR-212-3p抑制物组比较,H_(2)O_(2)+miR-212-3p抑制物+MAPK3干扰组β-半乳糖苷酶活性升高(P<0.05)。与H_(2)O_(2)+对照抑制物组比较,H_(2)O_(2)+miR-212-3p抑制物组细胞中p16和p21蛋白表达降低(P<0.05);与H_(2)O_(2)+miR-212-3p抑制物组比较,H_(2)O_(2)+miR-212-3p抑制物+MAPK3干扰组细胞中p16和p21蛋白表达升高(P<0.05)。⑤结果表明,下调miR-212-3p可抑制大鼠骨髓间充质干细胞衰老,其作用机制可能是通过靶向上调MAPK3表达实现的。

中药活性成分干预骨髓间充质干细胞衰老分子机制的研究进展

骨髓间充质干细胞(bone marrow mesen-chymal stem cells,BM-MSCs)衰老可诱发骨组织退行性病变和慢性炎症,并降低其用于细胞治疗的效果。越来越多的中药活性成分被证实可干预BM-MSCs衰老,在多种疾病的预防和治疗中发挥重要作用并提高细胞治疗效果。深入理解中药活性成分干预BM-MSCs衰老的分子机制既可提高基于BM-MSCs的疾病预防治疗和细胞移植效果,也为中药在干细胞研究应用领域里的发展奠定基础。

丁苯酞对大鼠骨髓间充质干细胞炎性损伤的改善作用及机制

目的 研究丁苯酞对大鼠骨髓间充质干细胞(BMSCs)炎性损伤的改善作用及其可能机制。方法 将大鼠BMSCs分为对照组、模型组和丁苯酞低、中、高浓度组(10、20、50μmol/L)。体外培养BMSCs并采用脂多糖(终浓度为10 mg/L)建立炎性损伤模型,经丁苯酞干预后检测细胞存活率、凋亡率和细胞培养液中肿瘤坏死因子α(TNF-α)、白细胞介素1β(IL-1β)、白细胞介素6(IL-6)含量以及细胞中核因子κB(NF-κB)p65 mRNA和胱天蛋白酶3(caspase-3)、B细胞淋巴瘤2(Bcl-2)、Bcl-2相关X蛋白(Bax)和NF-κB p65蛋白表达。结果 与对照组比较,模型组细胞存活率和Bcl-2蛋白表达水平均显著降低(P<0.05);细胞凋亡率,TNF-α、IL-1β、IL-6含量,NF-κB p65 mRNA以及caspase-3、Bax、NF-κB p65蛋白表达水平均显著升高(P<0.05)。与模型组比较,丁苯酞各浓度组上述指标均显著逆转(P<0.05),且呈浓度依赖性。结论 丁苯酞对脂多糖诱导的BMSCs炎性损伤具有改善作用,其机制可能与抑制NF-κB信号通路有关。

低氧低糖及血清剥夺联合处理抑制Nrf2信号通路诱发大鼠骨髓间充质干细胞氧化应激和凋亡

目的探讨低氧低糖血清剥夺(GSDH)处理对大鼠骨髓间充质干细胞(BMSCs)氧化应激及凋亡的影响。方法在体外对提取纯化后的原代BMSCs利用低氧(1%O_(2))、低糖(1.0 g/L)及血清剥夺联合处理建立BMSCs细胞损伤模型。采用集落形成实验、细胞周期测定以及CCK-8实验检测细胞增殖能力;划痕实验和Transwell实验检测细胞迁移能力;通过细胞凋亡试剂(AnnexinV-FITC/PI)、线粒体膜电位检测试剂(JC-1)染色和线粒体荧光探针(Mito-Trancker)检测细胞凋亡;细胞活性氧簇(ROS)和钙离子(Fluo-4AM)检测细胞氧化应激水平;Western blotting检测抗氧化应激相关分子谷胱甘肽过氧化物酶4(GPX4)等以及核因子红细胞系2相关因子2(Nrf2)信号通路中关键分子的蛋白表达水平。结果大鼠原代BMSCs表面标志物高表达CD29、CD71,低表达CD45、CD34;GSDH处理抑制BMSCs细胞增殖(P<0.05)和迁移(P<0.05),增加ROS和钙离子水平(P<0.05),且抑制抗氧化应激相关分子GPX4等蛋白表达(P<0.01);与空白对照组相比,GSDH处理后BMSCs凋亡显著升高(P<0.05),线粒体膜电位降低(P<0.01),网络化减少(P<0.01)。Nrf2信号通路中Nrf2蛋白及下游关键分子的蛋白表达水平均降低(P<0.05)。结论GSDH处理诱发的BMSCs氧化应激及进一步导致的凋亡损伤与Nrf2信号通路被抑制有关。