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Applications of stem cells and bioprinting for potential treatment of diabetes
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作者 Shweta Anil Kumar Monica Delgado +1 位作者 Victor E Mendez Binata Joddar 《世界干细胞杂志:英文版(电子版)》 2019年第1期13-32,共20页
Currently,there does not exist a strategy that can reduce diabetes and scientists are working towards a cure and innovative approaches by employing stem cellbased therapies.On the other hand,bioprinting technology is ... Currently,there does not exist a strategy that can reduce diabetes and scientists are working towards a cure and innovative approaches by employing stem cellbased therapies.On the other hand,bioprinting technology is a novel therapeutic approach that aims to replace the diseased or lostβ-cells,insulin-secreting cells in the pancreas,which can potentially regenerate damaged organs such as the pancreas.Stem cells have the ability to differentiate into various cell lines including insulinproducing cells.However,there are still barriers that hamper the successful differentiation of stem cells intoβ-cells.In this review,we focus on the potential applications of stem cell research and bioprinting that may be targeted towards replacing theβ-cells in the pancreas and may offer approaches towards treatment of diabetes.This review emphasizes on the applicability of employing both stem cells and other cells in 3D bioprinting to generate substitutes for diseasedβ-cells and recover lost pancreatic functions.The article then proceeds to discuss the overall research done in the field of stem cell-based bioprinting and provides future directions for improving the same for potential applications in diabetic research. 展开更多
关键词 BIOPRINTING Tissue engineering Pluripotent STEM CELLS Mesenchymal STEM CELLS HUMAN embryonic STEM Adult HUMAN liver CELLS β-cells Islet CELLS Biomaterials Bioink STEM cell DIABETES
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Induced pluripotent stem cells from Huntington’s disease patients:a promising approach to define and correct disease-related alterations 预览
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作者 Azra Fatima Ricardo Gutiérrez-Garcia David Vilchez 《中国神经再生研究:英文版》 SCIE CAS CSCD 2019年第5期769-770,共2页
Adult somatic cells such as skin or blood cells from either health donors or patients can be reprogrammed into induced pluripotent stem cells(iPSCs).Given their unlimited self-renewal and differentiation capacities,iP... Adult somatic cells such as skin or blood cells from either health donors or patients can be reprogrammed into induced pluripotent stem cells(iPSCs).Given their unlimited self-renewal and differentiation capacities,iPSCs are an invaluable resource to generate terminally differentiated cells.Thus,iPSCs can facilitate the study of human diseases and drug screening,holding great promise for regenerative medicine.Another significant advantage of iPSC disease-modeling is that normal and mutant proteins are expressed at endogenous levels.In addition,subtle phenotypes and the effects of genetic background variations can be assessed by comparison between iPSC lines obtained from different patients and healthy donors as well as isogenic lines,in which disease-related mutations are corrected. 展开更多
关键词 ADULT SOMATIC CELLS skin or blood CELLS Huntington’s DISEASE PATIENTS
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Gene expression changes in dorsal root ganglia following peripheral nerve injury:roles in inflammation,cell death and nociception 预览
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作者 Sarah L. Martin Adam J. Reid +2 位作者 Alexei Verkhratsky Valerio Magnaghi Alessandro Faroni 《中国神经再生研究:英文版》 SCIE CAS CSCD 2019年第6期939-947,共9页
Subsequent to a peripheral nerve injury,there are changes in gene expression within the dorsal root ganglia in response to the damage.This review selects factors which are well-known to be vital for inflammation,cell ... Subsequent to a peripheral nerve injury,there are changes in gene expression within the dorsal root ganglia in response to the damage.This review selects factors which are well-known to be vital for inflammation,cell death and nociception,and highlights how alterations in their gene expression within the dorsal root ganglia can affect functional recovery.The majority of studies used polymerase chain reaction within animal models to analyse the dynamic changes following peripheral nerve injuries.This review aims to highlight the factors at the gene expression level that impede functional recovery and are hence are potential targets for therapeutic approaches.Where possible the experimental model,specific time-points and cellular location of expression levels are reported. 展开更多
关键词 Gene expression polymerase chain reaction dorsal root GANGLIA INFLAMMATION NOCICEPTION cell death peripheral NERVE injury Schwann CELLS satellite GLIAL CELLS NERVE regeneration
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Human adult pluripotency:Facts and questions
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作者 Luminita Labusca Kaveh Mashayekhi 《世界干细胞杂志:英文版(电子版)》 2019年第1期1-12,共12页
Cellular reprogramming and induced pluripotent stem cell(IPSC)technology demonstrated the plasticity of adult cell fate,opening a new era of cellular modelling and introducing a versatile therapeutic tool for regenera... Cellular reprogramming and induced pluripotent stem cell(IPSC)technology demonstrated the plasticity of adult cell fate,opening a new era of cellular modelling and introducing a versatile therapeutic tool for regenerative medicine.While IPSCs are already involved in clinical trials for various regenerative purposes,critical questions concerning their medium-and long-term genetic and epigenetic stability still need to be answered.Pluripotent stem cells have been described in the last decades in various mammalian and human tissues(such as bone marrow,blood and adipose tissue).We briefly describe the characteristics of human-derived adult stem cells displaying in vitro and/or in vivo pluripotency while highlighting that the common denominators of their isolation or occurrence within tissue are represented by extreme cellular stress.Spontaneous cellular reprogramming as a survival mechanism favoured by senescence and cellular scarcity could represent an adaptative mechanism.Reprogrammed cells could initiate tissue regeneration or tumour formation dependent on the microenvironment characteristics.Systems biology approaches and lineage tracing within living tissues can be used to clarify the origin of adult pluripotent stem cells and their significance for regeneration and disease. 展开更多
关键词 HUMAN ADULT PLURIPOTENT STEM CELLS Induced PLURIPOTENT STEM CELLS Reprogramming Cellular stress
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Safety of intrathecal injection of Wharton's jelly-derived mesenchymal stem cells in amyotrophic lateralsclerosis therapy 预览
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作者 Monika Barczewska Mariusz Grudniak +5 位作者 Stanislaw Maksymowicz Tomasz Siwek Tomasz Oldak Katarzyna Jezierska-Wozniak Dominika Gladysz Wojciech Maksymowicz 《中国神经再生研究:英文版》 SCIE CAS CSCD 2019年第2期313-318,共6页
Animal experiments have confirmed that mesenchymal stem cells can inhibit motor neuron apoptosis and inflammatory factor expression and increase neurotrophic factor expression. Therefore, mesenchymal stem cells have b... Animal experiments have confirmed that mesenchymal stem cells can inhibit motor neuron apoptosis and inflammatory factor expression and increase neurotrophic factor expression. Therefore, mesenchymal stem cells have been shown to exhibit prospects in the treatment of amyotrophic lateral sclerosis. However, the safety of their clinical application needs to be validated. To investigate the safety of intrathecal injection of Wharton's jelly-derived mesenchymal stem cells in amyotrophic lateral sclerosis therapy, 43 patients (16 females and 27 males, mean age of 57.3 years) received an average dose of 0.42 × 106 cells/kg through intrathecal administration at the cervical, thoracic or lumbar region depending on the clinical symptoms. There was a 2 month interval between two injections. The adverse events occurring during a 6-month treatment period were evaluated. No adverse events occurred. Headache occurred in one case only after first injection of stem cells. This suggests that intrathecal injection of Wharton's Jelly-derived mesenchymal stem cells is well tolerated in patients with amyotrophic lateral sclerosis. This study was approved by the Bioethical Committee of School of Medicine, University of Warmia and Mazury in Olsztyn, Poland (approval No. 36/2014 and approval No. 8/2016). This study was registered with the ClinicalTrials.gov (identifier: NCT02881476) on August 29, 2016. 展开更多
关键词 amyotrophic lateral sclerosis STEM CELLS THERAPY intrathecal injections Wharton's jelly-derived mesenchymal STEM CELLS adverse events safety cerebrospinal fluid neural regeneration
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Differentiation of retinal ganglion cells from induced pluripotent stem cells: a review
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作者 Shang-Li Ji Shi-Bo Tang 《国际眼科杂志:英文版》 SCIE CAS 2019年第1期152-160,共9页
Glaucoma is a common optic neuropathy that is characterized by the progressive degeneration of axons and the loss of retinal ganglion cells(RGCs). Glaucoma is one of the leading causes of irreversible blindness worldw... Glaucoma is a common optic neuropathy that is characterized by the progressive degeneration of axons and the loss of retinal ganglion cells(RGCs). Glaucoma is one of the leading causes of irreversible blindness worldwide. Current glaucoma treatments only slow the progression of RGCs loss. Induced pluripotent stem cells(iPSCs) are capable of differentiating into all three germ layer cell lineages. iPSCs can be patient-specific,making iPSC-derived RGCs a promising candidate for cell replacement. In this review, we focus on discussing the detailed approaches used to differentiate iPSCs into RGCs. 展开更多
关键词 GLAUCOMA RETINAL GANGLION CELLS induced PLURIPOTENT stem CELLS DIFFERENTIATION
The protective effect of zeaxanthin on human limbal and conjunctival epithelial cells against UV-induced cell death and oxidative stress
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作者 Yue Huang Chun Shi Jing Li 《国际眼科杂志:英文版》 SCIE CAS 2019年第3期369-374,共6页
AIM: To explore the protective effect of zeaxanthin on human limbal and conjunctival epithelial cells against UVradiation and excessive oxidative stress.METHODS: Human limbal and conjunctival epithelial cells were iso... AIM: To explore the protective effect of zeaxanthin on human limbal and conjunctival epithelial cells against UVradiation and excessive oxidative stress.METHODS: Human limbal and conjunctival epithelial cells were isolated from cadaver and cultured in vitro. They were challenged with UVB radiation and H2 O2 with and without zeaxanthin pretreatment. Cell viability, p38 and c-JUN NH(2)-terminal kinase(JNK) phosphorylation, IL-6, IL-8 and MCP-1 secretion and malondialdehyde(MDA) content were measured.RESULTS: Zeaxanthin had no measurable cytotoxicity on limbal or conjunctival epithelial cells when used at concentrations of 5 μg/mL and below. At 30 mJ/cm2 UVB, the pretreatment of zeaxanthin increased the percentage of live cells from 50% to 69%(P=0.01) and from 66% to 75%(P=0.05) for limbal and conjunctival epithelial cells, respectively. The concentrations of IL-6, IL-8 and MCP-1 in the culture medium reduced to 66%(for IL-6 and MCP-1)and 56%(for IL-8) of the levels without zeaxanthin. This was accompanied by reduced p38 and JNK protein phosphorylation. Pretreatment of zeaxanthin also reduced intracellular MDA content caused by H2 O2 stimulation from 0.86 μmol/L to 0.52 μmol/L(P=0.02) in limbal epithelial cells and from 0.96 μmol/L to 0.56 μmol/L in conjunctival epithelial cells(P=0.03). However, zeaxanthin did nothave significant effect on H2 O2-induced cell death in limbal or conjunctival epithelial cells.CONCLUSION: Zeaxanthin is an effective reagent in reducing the detrimental effect of UV-radiation and oxidative stress on ocular surface epithelial cells. 展开更多
关键词 ZEAXANTHIN UV-radiation oxidative stress MALONDIALDEHYDE limbal EPITHELIAL CELLS CONJUNCTIVAL EPITHELIAL CELLS
Mesenchymal stem cells and the neuronal microenvironment in the area of spinal cord injury 预览
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作者 Yana O. Mukhamedshina Olga A. Gracheva +2 位作者 Dina M. Mukhutdinova Yurii A. Chelyshev Albert A. Rizvanov 《中国神经再生研究:英文版》 SCIE CAS CSCD 2019年第2期227-237,共11页
Cell-based technologies are used as a therapeutic strategy in spinal cord injury (SCI). Mesenchymal stem cells (MSCs), which secrete various neurotrophic factors and cytokines, have immunomodulatory, anti- apoptotic a... Cell-based technologies are used as a therapeutic strategy in spinal cord injury (SCI). Mesenchymal stem cells (MSCs), which secrete various neurotrophic factors and cytokines, have immunomodulatory, anti- apoptotic and anti-inflammatory effects, modulate reactivity/phenotype of astrocytes and the microglia, thereby promoting neuroregeneration seem to be the most promising. The therapeutic effect of MSCs is due to a paracrine mechanism of their action, therefore the survival of MSCs and their secretory phenotype is of particular importance. Nevertheless, these data are not always reported in efficacy studies of MSC therapy in SCI. Here, we provide a review with summaries of preclinical trials data evaluating the efficacy of MSCs in animal models of SCI. Based on the data collected, we have tried (1) to establish the behavior of MSCs after transplantation in SCI with an evaluation of cell survival, migration potential, distribution in the area of injured and intact tissue and possible differentiation; (2) to determine the effects MSCs on neuronal microenvironment and correlate them with the efficacy of functional recovery in SCI; (3) to ascertain the conditions under which MSCs demonstrate their best survival and greatest efficacy. 展开更多
关键词 spinal cord injury mesenchymal stem CELLS survival migration Rho/ROCK/PTEN ASTROCYTES MICROGLIA myelin-forming CELLS AXON growth tissue integrity
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Exogenous neural stem cell transplantation for cerebral ischemia 预览
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作者 Ling-Yi Liao Benson Wui-Man Lau +1 位作者 Dalinda Isabel Sánchez-Vida?a Qiang Gao 《中国神经再生研究:英文版》 SCIE CAS CSCD 2019年第7期1129-1137,共9页
Cerebral ischemic injury is the main manifestation of stroke,and its incidence in stroke patients is 70–80%.Although ischemic stroke can be treated with tissue-type plasminogen activator,its time window of effectiven... Cerebral ischemic injury is the main manifestation of stroke,and its incidence in stroke patients is 70–80%.Although ischemic stroke can be treated with tissue-type plasminogen activator,its time window of effectiveness is narrow.Therefore,the incidence of paralysis,hypoesthesia,aphasia,dysphagia,and cognitive impairment caused by cerebral ischemia is high.Nerve tissue regeneration can promote the recovery of the aforementioned dysfunction.Neural stem cells can participate in the reconstruction of the damaged nervous system and promote the recovery of nervous function during self-repair of damaged brain tissue.Neural stem cell transplantation for ischemic stroke has been a hot topic for more than 10 years.This review discusses the treatment of ischemic stroke with neural stem cells,as well as the mechanisms of their involvement in stroke treatment. 展开更多
关键词 nerve REGENERATION STEM CELL therapy NEURAL STEM cells CELL transplantation ischemic stroke cerebral ischemia NEUROPLASTICITY functional recovery NEURAL REGENERATION
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New findings showing how DNA methylation influences diseases
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作者 Fabio Sallustio Loreto Gesualdo Anna Gallone 《世界生物化学杂志:英文版(电子版)》 2019年第1期1-6,共6页
In 1975,Holliday and Pugh as well as Riggs independently hypothesized that DNA methylation in eukaryotes could act as a hereditary regulation mechanism that influences gene expression and cell differentiation.Interest... In 1975,Holliday and Pugh as well as Riggs independently hypothesized that DNA methylation in eukaryotes could act as a hereditary regulation mechanism that influences gene expression and cell differentiation.Interest in the study of epigenetic processes has been inspired by their reversibility as well as their potentially preventable or treatable consequences.Recently,we have begun to understand that the features of DNA methylation are not the same for all cells.Major differences have been found between differentiated cells and stem cells.Methylation influences various pathologies,and it is very important to improve the understanding of the pathogenic mechanisms.Epigenetic modifications may take place throughout life and have been related to cancer,brain aging,memory disturbances,changes in synaptic plasticity,and neurodegenerative diseases,such as Parkinson’s disease and Huntington’s disease.DNA methylation also has a very important role in tumor biology.Many oncogenes are activated by mutations in carcinogenesis.However,many genes with tumor-suppressor functions are“silenced”by the methylation of CpG sites in some of their regions.Moreover,the role of epigenetic alterations has been demonstrated in neurological diseases.In neuronal precursors,many genes associated with development and differentiation are silenced by CpG methylation.In addition,recent studies show that DNA methylation can also influence diseases that do not appear to be related to the environment,such as IgA nephropathy,thus affecting the expression of some genes involved in the T-cell receptor signaling.In conclusion,DNA methylation provides a whole series of fundamental information for the cell to regulate gene expression,including how and when the genes are read,and it does not depend on the DNA sequence. 展开更多
关键词 DNA METHYLATION Stem cells ENHANCER IGA NEPHROPATHY Gene regulation
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Effects of Ginkgo biloba extract EGb761 on neural differentiation of stem cells offer new hope for neurological disease treatment 预览
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作者 Chao Ren Yong-Qiang Ji +5 位作者 Hong Liu Zhe Wang Jia-Hui Wang Cai-Yi Zhang Li-Na Guan Pei-Yuan Yin 《中国神经再生研究:英文版》 SCIE CAS CSCD 2019年第7期1152-1157,共6页
Stem cell transplantation has brought new hope for the treatment of neurological diseases.The key to stem cell therapy lies in inducing the specific differentiation of stem cells into nerve cells.Because the different... Stem cell transplantation has brought new hope for the treatment of neurological diseases.The key to stem cell therapy lies in inducing the specific differentiation of stem cells into nerve cells.Because the differentiation of stem cells in vitro and in vivo is affected by multiple factors,the final differentiation outcome is strongly associated with the microenvironment in which the stem cells are located.Accordingly,the optimal microenvironment for inducing stem cell differentiation is a hot topic.EGb761 is extracted from the leaves of the Ginkgo biloba tree.It is used worldwide and is becoming one of the focuses of stem cell research.Studies have shown that EGb761 can antagonize oxygen free radicals,stabilize cell membranes,promote neurogenesis and synaptogenesis,increase the level of brain-derived neurotrophic factors,and replicate the environment required during the differentiation of stem cells into nerve cells.This offers the possibility of using EGb761 to induce the differentiation of stem cells,facilitating stem cell transplantation.To provide a comprehensive reference for the future application of EGb761 in stem cell therapy,we reviewed studies investigating the influence of EGb761 on stem cells.These started with the composition and neuropharmacology of EGb761,and eventually led to the finding that EGb761 and some of its important components play important roles in the differentiation of stem cells and the protection of a beneficial microenvironment for stem cell transplantation. 展开更多
关键词 nerve REGENERATION GINKGO biloba extract GINKGOLIDE B traditional Chinese medicine STEM cells induction of differentiation STEM cell transplantation SYNAPTIC plasticity pharmacological effect NEUROLOGICAL diseases nervous systems neural REGENERATION
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Anti-inflammatory potential of human corneal stroma-derived stem cells determined by a novel in vitro corneal epithelial injury model
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作者 Mariana Lizeth Orozco Morales Nagi M Marsit +2 位作者 Owen D McIntosh Andrew Hopkinson Laura E Sidney 《世界干细胞杂志:英文版(电子版)》 2019年第2期84-99,共16页
BACKGROUND An in vitro injury model mimicking a corneal surface injury was optimised using human corneal epithelial cells (hCEC). AIM To investigate whether corneal-stroma derived stem cells (CSSC) seeded on an amniot... BACKGROUND An in vitro injury model mimicking a corneal surface injury was optimised using human corneal epithelial cells (hCEC). AIM To investigate whether corneal-stroma derived stem cells (CSSC) seeded on an amniotic membrane (AM) construct manifests an anti-inflammatory, healing response. METHODS Treatment of hCEC with ethanol and pro-inflammatory cytokines were compared in terms of viability loss, cytotoxicity, and pro-inflammatory cytokine release, in order to generate the in vitro injury. This resulted in an optimal injury of 20%(v/v) ethanol for 30 s with 1 ng/mL interleukin-1 (IL-1) beta. Co-culture experiments were performed with CSSC alone and with CSSC-AM constructs. The effect of injury and co-culture on viability, cytotoxicity, IL-6 and IL-8 production, and IL1B, TNF, IL6, and CXCL8 mRNA expression were assessed. RESULTS Co-culture with CSSC inhibited loss of hCEC viability caused by injury. Enzyme linked immunosorbent assay and polymerase chain reaction showed a significant reduction in the production of IL-6 and IL-8 pro-inflammatory cytokines, and reduction in pro-inflammatory cytokine mRNA expression during co-culture with CSSC alone and with the AM construct. These results confirmed the therapeutic potential of the CSSC and the possible use of AM as a cell carrier for application to the ocular surface.CONCLUSION CSSC were shown to have a potentially therapeutic anti-inflammatory effect when treating injured hCEC, demonstrating an important role in corneal regeneration and wound healing, leading to an improved knowledge of their potential use for research and therapeutic purposes. 展开更多
关键词 CORNEA CORNEAL injuries INJURY MODEL epithelium stromaderived stem cells AMNION ANTI-INFLAMMATORY Cell therapy
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Ginsenoside Rgl protects against ischemic/reperfusioninduced neuronal injury through miR-144/Nrf2/ARE pathway
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作者 Shi-feng Chu Zhao Zhang +10 位作者 Xin Zhou Wen-bin He Chen Chen Piao Luo Dan-dan Liu Qi-di Ai Hai-fan Gong Zhen-zhen Wang Hong-shuo Sun Zhong-ping Feng Nai-hong Chen 《中国药理学报:英文版》 SCIE CAS CSCD 2019年第1期13-25,共13页
Ginsenoside Rg1 (Rg1),a saponin extracted from Panax ginseng,has been well documented to be effective against ischemic/ reperfusion (I/R)neuronal injury.However,the underlying mechanisms remain obscure.In the present ... Ginsenoside Rg1 (Rg1),a saponin extracted from Panax ginseng,has been well documented to be effective against ischemic/ reperfusion (I/R)neuronal injury.However,the underlying mechanisms remain obscure.In the present study,we investigated the roles of Nrf2 and miR-144 in the protective effects of Rgl against I/R-induced neuronal injury.In OGD/R-treated PC12 cells,Rgl (0.01-1 μmol/L)dose-dependently attenuated the cell injury accompanied by prolonging nuclear accumulation of Nrf2,enhancing the transcriptional activity of Nrf2,as well as promoting the expression of ARE-target genes.The activation of the Nrf2/ARE pathway by Rgl was independent of disassociation with Keapl,but resulted from post-translational regulations.Knockdown of Nrf2 abolished all the protective changes of Rgl in OG-D/R-treated PC12 cells.Furthermore,Rgl treatment significantly decreased the expression of miR-144,which downregulated Nrf2 production by targeting its 3'-untranlated region after OGD/R.Knockdown of Nrf2 had no effect on the expression of miR-144,suggesting that miR-144 was an upstream regulator of Nrf2.We revealed that there was a direct binding between Nrf2 and miR-144 in PC12 cells.Application of anti-miR-144 occluded the activation of the Nrf2/ ARE pathway by Rgl in OGD/R-treated PC12 cells.In tMCAO rats,administration of Rgl (20 mg/kg).significantly alleviated ischemic injury,and activated Nff2/ARE pathway.The protective effects of Rgl were abolished by injecting of AAV-HIF-miR-144-shRNA into the predicted ischemic penumbra.In conclusion,our results demonstrate that Rgl alleviates oxidative,stress after I/R through inhibiting miR-144 activity and subsequently promoting the Nrf2/ARE pathway at the post-translational-level. 展开更多
关键词 STROKE GINSENOSIDE Rgl ischemic/reperfusion oxidative stress Nrf2/ARE miR-144 PC12 cells tMCAO rats
Rh-doped PdAg nanoparticles as efficient methanol tolerance electrocatalytic materials for oxygen reduction
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作者 Yingjun Sun Bolong Huang +6 位作者 Nuoyan Xu Yingjie Li Mingchuan Luo Chunji Li Yingnan Qin Lei Wang Shaojun Guo 《科学通报:英文版》 SCIE EI CSCD 2019年第1期54-62,共9页
Direct methanol fuel cells (DMFCs)have received extensive attention on their high efficiency,high reliability,and no carbon emission.Unfortunately,the poor methanol tolerance and sluggish oxygen reduc- tion reaction (... Direct methanol fuel cells (DMFCs)have received extensive attention on their high efficiency,high reliability,and no carbon emission.Unfortunately,the poor methanol tolerance and sluggish oxygen reduc- tion reaction (ORR)at cathode have seriously hindered their further development.Herein we report the synthesis of a new class of Rh-doped PdAg alloy nanoparticles (NPs)for boosting ORR activity with high methanol tolerance capacity concurrently.The ORR mass activity of typical Rh4Pd40Ag55 NPs is 4.2 times higher than that of commercial Pt catalyst.Moreover,it shows a great methanol tolerance capability by maintaining 92.4%in ORR mass activity in alkaline solution with 0.1 mol L^-1 methanol,against a big decrease of almost 100% for commercial Pt.Even after 30,000 potential cycles with 1.0 mol L^-1 methanol, Rh4Pd40Ag56 NPs still retain ORR mass activity of up to 68.3%.DFT calculations reveal that excellent ORR performance with excellent methanol tolerance originates the active d-band-pinning engineering for an efficient site-independent electron-transfer.A generalized d-band mediated fine electron-transfer tuning path has blueprinted for effectively minimizing intrinsic ORR barriers with high current density.The present work highlights the key role of Rh doping in enhancing the ORR activity and methanol tolerance abil- ity of PdAg NPs for future high-performance DMFCs. 展开更多
关键词 Rh-doped Multimetallic Oxygen reduction METHANOL TOLERANCE Fuel cells
Hydrothermally induced diagenesis:Evidence from shallow marinedeltaic sediments,Wilhelmoya,Svalbard 预览
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作者 Beyene G.Haile Urszula Czarniecka +4 位作者 Kelai Xi Aleksandra Smyrak-Sikora Jens Jahren Alvar Braathen Helge Hellevang 《地学前缘:英文版》 CAS CSCD 2019年第2期629-649,共21页
Sedimentary basins containing igneous intrusions within sedimentary reservoir units represent an important risk in petroleum exploration.The Upper Triassic to Lower Jurassic sediments at Wilhelm?ya(Svalbard)contains r... Sedimentary basins containing igneous intrusions within sedimentary reservoir units represent an important risk in petroleum exploration.The Upper Triassic to Lower Jurassic sediments at Wilhelm?ya(Svalbard)contains reservoir heterogeneity as a result of sill emplacement and represent a unique case study to better understand the effect of magmatic intrusions on the general burial diagenesis of siliciclastic sediments.Sills develop contact metamorphic aureoles by conduction as presented in many earlier studies.However,there is significant impact of localized hydrothermal circulation systems affecting reservoir sediments at considerable distance from the sill intrusions.Dolerite sill intrusions in the studied area are of limited vertical extent(~12 m thick),but created localized hydrothermal convection cells affecting sediments at considerable distance(more than five times the thickness of the sill)from the intrusions.We present evidence that the sedimentary sequence can be divided into two units:(1)the bulk poorly lithified sediment with a maximum burial temperature much lower than 60-70℃,and(2)thinner intervals outside the contact zone that have experienced hydrothermal temperatures(around 140℃).The main diagenetic alteration associated with normal burial diagenesis is minor mechanical plastic deformation of ductile grains such as mica.Mineral grain contacts show no evidence of pressure dissolution and the vitrinite reflectance suggests a maximum temperature of~40℃.Contrary to this,part of the sediment,preferentially along calcite cemented flow baffles,show evidence of hydrothermal alteration.These hydrothermally altered sediment sections are characterized by recrystallized carbonate cemented intervals.Further,the hydrothermal solutions have resulted in localized sericitization(illitization)of feldspars,albitization of both K-feldspar and plagioclase and the formation of fibrous illite nucleated on kaolinite.These observations suggest hydrothermal alteration at T>120-140℃at distances considerably further 展开更多
关键词 DIAGENESIS SILL INTRUSIONS Hydrothermal convection cells Carbonate cement Sericitization of FELDSPARS
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Construction of a full-thickness human corneal substitute from anterior acellular porcine corneal matrix and human corneal cells
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作者 Kai Zhang Xiao-Xiao Ren +2 位作者 Ping Li Kun-Peng Pang Hong Wang 《国际眼科杂志:英文版》 SCIE CAS 2019年第3期351-362,共12页
AIM: To construct functional human full-thickness corneal replacements.METHODS: Acellular porcine corneal matrix(APCM) was developed from porcine cornea by decellulariztion. The biomechanical properties of anterior-AP... AIM: To construct functional human full-thickness corneal replacements.METHODS: Acellular porcine corneal matrix(APCM) was developed from porcine cornea by decellulariztion. The biomechanical properties of anterior-APCM(AAPCM) and posterior-APCM(PAPCM) were checked using uniaxial tensile testing. Human corneal cells were obtained by cell culture. Suspending ring was designed by deformation of an acupuncture needle. MTT cytotoxicity assay was used to check the cytotoxicity of suspending ring soaking solutions. A new three-dimensional organ culture system was established by combination of suspending ring, 48-well plate and medium together. A human full-thickness corneal substitute was constructed from human corneal cells with AAPCM in an organ coculture system. Biochemical marker expression of the construct was measured by immunofluorescent staining and morphological structures were observed using scanning electron microscopy. Pump function and biophysical properties were examined by penetrating keratoplasty and follow-up clinical observations.RESULTS: There were no cells in the AAPCM or PAPCM, whereas collagen fibers, Bowman’s membrane, and Descemet’s membrane were retained. The biomechanical property of AAPCM was better than PAPCM. Human corneal cells grew better on the AAPCM than on the PAPCM.There was no cytotoxicity for the suspending ring soaking solutions. For the constructed full-depth human corneal replacements keratocytes scattered uniformly throughout the AAPCM and expressed vimentin. The epithelial layer was located on the surface of Bowman’s membrane and composed of three or four layers of epithelial cells expressing cytokeratin 3. One layer of endothelial cells covered the stromal surface of AAPCM, expressed Na+/K+ATPase and formed the endothelial layer. The construct was similar to normal human corneas, with many microvilli on the epithelial cell surface, stromal cells with a long shuttle shape, and zonula occludens on the interface of endothelial cells. The construct withstood surgical procedu 展开更多
关键词 full-thickness human CORNEAL SUBSTITUTE anterior-acellular PORCINE CORNEAL MATRIX posterior-acellular PORCINE CORNEAL MATRIX human CORNEAL cells
PD-1抗体抗癌新发现:杀伤性T细胞的抗肿瘤活性由树突状细胞启动
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作者 郭琳 《海南医学》 CAS 2019年第1期F0003-F0004,共2页
传统观点认为,PD-1抗体抗癌机制为PD-1抗体与T细胞上PD-1受体结合并直接激活T细胞启动免疫反应。然而,事情并非这么简单。最近,麻省总医院的GARRIS等在《Immunity》上发表的研究成果进一步解析了PD-1抗体抗癌的机制。该研究发现,当PD-1... 传统观点认为,PD-1抗体抗癌机制为PD-1抗体与T细胞上PD-1受体结合并直接激活T细胞启动免疫反应。然而,事情并非这么简单。最近,麻省总医院的GARRIS等在《Immunity》上发表的研究成果进一步解析了PD-1抗体抗癌的机制。该研究发现,当PD-1抗体与T细胞上PD-1受体结合后,由树突状细胞(dendritic cells,DCs)通过表达IL-12启动杀伤性T细胞的抗肿瘤活性。 展开更多
关键词 杀伤性T细胞 PD-1 树突状细胞 抗肿瘤活性 抗癌机制 抗体 受体结合 cells
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Mucin-like glycopolymer gels in electrosensory tissues generate cues which direct electrolocation in amphibians and neuronal activation in mammals 预览
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作者 James Melrose 《中国神经再生研究:英文版》 SCIE CAS CSCD 2019年第7期1191-1195,共5页
Mucin-like glycoproteins have established roles in epithelial boundary protection and lubricative roles in some tissues.This mini-review illustrates alternative functional roles which rely on keratan sulphate and sial... Mucin-like glycoproteins have established roles in epithelial boundary protection and lubricative roles in some tissues.This mini-review illustrates alternative functional roles which rely on keratan sulphate and sialic acid modifications to mucin glycopolymers which convey charge properties suggestive of novel electroconductive properties not previously ascribed to these polymers.Many tumour cells express mucin-like glycopolymers modified with highly sulphated keratan sulphate and sialic which can be detected using diagnostic biosensors.The mucin-like keratan sulphate glycopolymer present in the ampullae of lorenzini is a remarkable sensory polymer which elasmobranch fish(sharks,rays,skate)use to detect weak electrical fields emitted through muscular activity of prey fish.Information on the proton gradients is conveyed to neuromast cells located at the base of the ampullae and mechanotransduced to neural networks.This ampullae keratan sulphate sensory gel is the most sensitive proton gradient detection polymer known in nature.This process is known as electrolocation,and allows the visualization of prey fish under conditions of low visibility.The bony fish have similar electroreceptors located along their lateral lines which consist of neuromast cells containing sensory hairs located within a cupula which contains a sensory gel polymer which detects distortions in fluid flow in channels within the lateral lines and signals are sent back to neural networks providing information on the environment around these fish.One species of dolphin,the Guiana dolphin,has electrosensory pits in its bill with similar roles to the ampullae but which have evolved from its vibrissal system.Only two terrestrial animals can undertake electrolocation,these are the Duck-billed platypus and long and short nosed Echidna.In this case the electrosensor is a highly evolved innervated mucous gland.The platypus has 40,000 electroreceptors around its bill through which it electrolocates food species.The platypus has poor eyesight,is a nocturn 展开更多
关键词 mucin GLYCOPOLYMERS keratan SULFATE ELECTROLOCATION monosulphated keratan SULFATE neuroregulation GLYCOSAMINOGLYCAN neurosensory hair cells neurosensory PROTEOGLYCAN
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Bone regeneration with adipose derived stem cells in a rabbit model
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作者 Michele Maglione Enrico Salvador +4 位作者 Maria E.Ruaro Mauro Melato Giuliana Tromba Daniele Angerame Lorenzo Bevilacqua 《生物医学研究杂志:英文版》 CAS CSCD 2019年第1期38-45,共8页
It has been shown that stem cells are able to calcify both in vitro and in vivo once implanted under the skin,if conveniently differentiated.Nowadays,however,a study on their efficiency in osseous regeneration does no... It has been shown that stem cells are able to calcify both in vitro and in vivo once implanted under the skin,if conveniently differentiated.Nowadays,however,a study on their efficiency in osseous regeneration does not exist in scientifìc literature and this very task is the real aim of the present experimentation.Five different defects of 6 mm in diameter and 2 mm in depth were created in the calvaria of 8 white New Zealand rabbits.Four defects were regenerated using 2 different conveniently modified scaffolds(Bio-Oss■Block and Bio-Oss Collagen■,Geistlich),with and without the aid of stem cells.After the insertion,the part was covered with a collagen membrane fixed by 5 modified titan pins(Altapin■).The defect in the front was left empty on purose as an intemal control to each animal.Two anirnals were sacrificed respectively after 2,4,6,10 weeks.The samples were evaluated with micro-CT and histological analysis.Micro-CT analysis revealed that the quantity of new bone for samples with Bio-Oss■Blockand stem cells was higher than for samples with Bio-Oss■Block alone.Histological analysis showed that regeneration occurred in an optimal way in every sample treated with scaffolds.The findings indicated that the use of adult stem cells combined with scaffolds accelerated some steps in normal osseous regeneration. 展开更多
关键词 BONE REGENERATION REGENERATIVE MEDICINE STEM cells TISSUE engineering
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Hesperetin derivative-12 (HDND-12) regulates macrophage polarization by modulating JAK2/STAT3 signaling pathway
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作者 KONG Ling-Na LIN Xiang +7 位作者 HUANG Cheng MA Tao-Tao MENG Xiao-Ming HU Chao-Jie WANG Qian-Qian LIU Yan-Hui SHI Qing-Ping LI Jun 《中国天然药物:英文版》 SCIE CAS CSCD 2019年第2期122-130,共9页
Macrophages show significant heterogeneity in function and phenotype, which could shift into different populations of cells in response to exposure to various micro-environmental signals. These changes, also termed as... Macrophages show significant heterogeneity in function and phenotype, which could shift into different populations of cells in response to exposure to various micro-environmental signals. These changes, also termed as macrophage polarization, of which play an important role in the pathogenesis of many diseases. Numerous studies have proved that Hesperidin(HDN), a traditional Chinese medicine, extracted from fruit peels of the genus citrus, play key roles in anti-inflammation, anti-tumor, anti-oxidant and so on. However, the role of HDN in macrophage polarization has never been reported. Additional, because of its poor water solubility and bioavailability. Our laboratory had synthesized many hesperidin derivatives. Among them, hesperidin derivatives-12(HDND-12) has better water solubility and bioavailability. So, we evaluated the role of HDND-12 in macrophage polarization in the present study. The results showed that the expression of Arginase-1(Arg-1), interleukin-10(IL-10), transforming growth factor β(TGF-β) were up-regulated by HDND-12, whereas the expression of inducible Nitric Oxide Synthase(iNOS) was down-regulated in LPS-and IFN-γ-treated(M1) RAW264.7 cells. Moreover, the expression of p-JAK2 and p-STAT3 were significantly decreased after stimulation with HDND-12 in M1-like macrophages. More importantly, when we taken AG490(inhibitor of JAK2/STAT3 signaling), the protein levels of iNOS were significantly reduced in AG490 stimulation group compare with control in LPS, IFN-γ and HDND-12 stimulation cells. Taken together, these findings indicated that HDND-12 could prevent polarization toward M1-like macrophages, at least in part, through modulating JAK2/STAT3 pathway. 展开更多
关键词 HESPERETIN Derivative-12 MACROPHAGE Polarization JAK2/STAT3 RAW264.7 cells
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