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1.
Stem Cell Rev Rep ; 2021 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-33389681

RESUMO

Dorsal root ganglia (DRG) sensory neurons can transmit information about noxious stimulus to cerebral cortex via spinal cord, and play an important role in the pain pathway. Alterations of the pain pathway lead to CIPA (congenital insensitivity to pain with anhidrosis) or chronic pain. Accumulating evidence demonstrates that nerve damage leads to the regeneration of neurons in DRG, which may contribute to pain modulation in feedback. Therefore, exploring the regeneration process of DRG neurons would provide a new understanding to the persistent pathological stimulation and contribute to reshape the somatosensory function. It has been reported that a subpopulation of satellite glial cells (SGCs) express Nestin and p75, and could differentiate into glial cells and neurons, suggesting that SGCs may have differentiation plasticity. Our results in the present study show that DRG-derived SGCs (DRG-SGCs) highly express neural crest cell markers Nestin, Sox2, Sox10, and p75, and differentiate into nociceptive sensory neurons in the presence of histone deacetylase inhibitor VPA, Wnt pathway activator CHIR99021, Notch pathway inhibitor RO4929097, and FGF pathway inhibitor SU5402. The nociceptive sensory neurons express multiple functionally-related genes (SCN9A, SCN10A, SP, Trpv1, and TrpA1) and are able to generate action potentials and voltage-gated Na+ currents. Moreover, we found that these cells exhibited rapid calcium transients in response to capsaicin through binding to the Trpv1 vanilloid receptor, confirming that the DRG-SGC-derived cells are nociceptive sensory neurons. Further, we show that Wnt signaling promotes the differentiation of DRG-SGCs into nociceptive sensory neurons by regulating the expression of specific transcription factor Runx1, while Notch and FGF signaling pathways are involved in the expression of SCN9A. These results demonstrate that DRG-SGCs have stem cell characteristics and can efficiently differentiate into functional nociceptive sensory neurons, shedding light on the clinical treatment of sensory neuron-related diseases.

2.
ACS Appl Mater Interfaces ; 12(47): 53021-53028, 2020 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-33170610

RESUMO

As a well-known electron-withdrawing group, benzo[c][1,2,5]thiadiazole (BT) has been intensively studied and adopted to construct polymer donors with tunable band gaps. However, polymer solar cells (PSCs) with BT-based polymer donors, limited by the weak absorption and inflexible energy level of fullerene derivatives, usually suffer mediocre power conversion efficiencies (PCEs). Here, through subtly tailoring a BT unit with asymmetric fluoro and alkyloxy groups and judiciously pairing a BT-based polymer donor with three narrow band gap non-fullerene acceptors (e.g., IEICO-4F, ITOIC-2F, and IDTCN-O), active layers with complementary absorption spectra, small lowest unoccupied molecular orbital (LUMO) offsets, and preferred morphologies have been achieved. Consequently, PSCs with excellent Jsc values (over 20 mA/cm2) and high PCEs up to 12.33% have been obtained. To the best of our knowledge, the value of 12.33% is among the highest PCEs for BT-based polymers in binary PSCs so far. This work demonstrates that the cooperative effect of energy levels, absorption spectra, and morphologies between the donors and acceptors is crucial for governing the performance of organic photovoltaics.

3.
Chem Asian J ; 15(14): 2198-2202, 2020 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-32484590

RESUMO

Two novel molecules TAP and TAH with pronounced reversible halochromic properties have been synthesized and fully characterized. Their butterfly-like structures have been confirmed through single-crystal X-ray diffraction. Their UV-Vis absorption after protonation dramatically red-shifted with naked-eye-visible color change in a very dilute concentration of 10-5 M. Note that the original color of the solution can be recovered after the neutralization with a base.

4.
Mol Metab ; 34: 16-26, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32180556

RESUMO

OBJECTIVE: Adenosine triphosphate (ATP)-binding cassette transporter A1 (ABCA1) influences hepatic cholesterol transportation. Accumulation of hepatic cholesterol leads to fatty liver disease, which is improved by glucagon-like peptide 1 (GLP-1) in diabetes. Therefore, we analyzed the molecular mechanism in the regulation of hepatic ABCA1 by GLP-1 analogue exendin-4. METHODS: Hepatic ABCA1 expression and transcription were checked by western blotting, real-time polymerase chain reaction (PCR), and luciferase assay in HepG2 cells. Chromatin immunoprecipitation (ChIP) and site-directed mutagenesis were employed to determine transcriptional regulation of the ABCA1 gene. Prolactin regulatory element-binding (PREB)-transgenic mice were generated to access the effect of exendin-4 on improving lipid accumulation caused by a high-fat diet (HFD). RESULTS: Exendin-4 stimulated hepatic ABCA1 expression and transcription via the Ca2+/calmodulin (CaM)-dependent protein kinase kinase/CaM-dependent protein kinase IV (CaMKK/CaMKIV) pathway, whereas GLP-1 receptor antagonist exendin9-39 cancelled this effect. Therefore, exendin-4 decreased hepatic lipid content. ChIP showed that PREB could directly bind to the ABCA1 promoter, which was enhanced by exendin-4. Moreover, PREB stimulated ABCA1 promoter activity, and mutation of PREB-binding site in ABCA1 promoter cancelled exendin-4-enhanced ABCA1 promoter activity. Silencing of PREB attenuated the effect of exendin-4 and induced hepatic cholesterol accumulation. Blockade of CaMKK by STO-609 or siRNA cancelled the upregulation of ABCA1 and PREB induced by exendin-4. In vivo, exendin-4 or overexpression of PREB increased hepatic ABCA1 expression and decreased hepatic lipid accumulation and high plasma cholesterol caused by a HFD. CONCLUSIONS: Our data shows that exendin-4 stimulates hepatic ABCA1 expression and decreases lipid accumulation by the CaMKK/CaMKIV/PREB pathway, suggesting that ABCA1 and PREB might be the therapeutic targets in fatty liver disease.

5.
J Mater Chem B ; 7(47): 7525-7539, 2019 12 21.
Artigo em Inglês | MEDLINE | ID: mdl-31720683

RESUMO

Transplantation of tissue-engineered neural scaffolds bears great potential for reconstructing neural circuits after spinal cord injury (SCI). In this study, a 3D porous silk fibrous scaffold (3D-SF) with biomimetic interconnected micro- to nanofibrous structure and good biocompatibility is fabricated. Then, a small-molecule combination CFLSSVY (CHIR99021, Forskolin, LDN193189, SB431542, SP600125, VPA, and Y27632) that efficiently reprograms rat dermal fibroblasts into neurons is screened, and these chemically induced neurons (CiNs) are shown to readily communicate on the 3D-SF and form neural scaffolds. After transplantation of these silk-based neural scaffolds into the stumps of transected spinal cords in rats, the damaged tissue is repaired significantly, as indicated by the reduced cavity areas, decreased GFAP expression, and improved axonal regeneration and myelination in the injury site. Moreover, the hindlimb movement and motor-nerve conductivity are greatly improved as indicated by the elevated BBB score, the alternate movement of two hindlimbs during the 45° inclined grid test, and the shortened latency and enhanced amplitude in cMEP detection. Together, these results demonstrate that transplantation of neural scaffolds consisting of 3D-SF and dermal fibroblast-reprogrammed neurons leads to significant nerve regeneration and functional recovery, providing a promising therapeutic strategy for SCI.


Assuntos
Nanofibras/química , Neurônios/transplante , Seda/química , Traumatismos da Medula Espinal/terapia , Tecidos Suporte/química , Animais , Axônios/fisiologia , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Barreira Hematoencefálica/metabolismo , Transdiferenciação Celular/efeitos dos fármacos , Células Cultivadas , Reprogramação Celular , Feminino , Fibroblastos/citologia , Humanos , Camundongos , Neurônios/citologia , Neurônios/metabolismo , Porosidade , Ratos , Ratos Sprague-Dawley , Regeneração/fisiologia
6.
Cell Transplant ; 28(12): 1552-1559, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31512502

RESUMO

In this study, we investigated how human umbilical cord mesenchymal stem cells exerted a neuroprotective effect via antiapoptotic mechanisms in a neonatal hypoxic-ischemic encephalopathy rat model. A total of 78 10-day old (P10) rats were used. After human umbilical cord mesenchymal stem cells were collected from human umbilical cords and amplified in culture, they were administered to rat subjects 1 h after induced hypoxic-ischemic encephalopathy treatment. The short-term (48 h) and long-term (28 day) outcomes were evaluated after human umbilical cord mesenchymal stem cells treatment using neurobehavioral function assessment. Triphenyltetrazolium chloride monohydrate staining was performed at 48 h. Beclin-2 and caspase-3 levels were evaluated with Western blot and real time polymerase chain reaction at 48 h. Human umbilical cord mesenchymal stem cells were collected and administrated to hypoxic-ischemic encephalopathy pups by intracerebroventricular injection. Hypoxic-ischemic encephalopathy typically induced significant delay in development and caused impairment in both cognitive and motor functions in rat subjects. Human umbilical cord mesenchymal stem cells were shown to ameliorate hypoxic-ischemic encephalopathy-induced damage and improve both cognitive and motor functions. Although hypoxic-ischemic encephalopathy induced significant expression of caspase-3 and Beclin-2, human umbilical cord mesenchymal stem cells decreased the expression of both of them. Human umbilical cord mesenchymal stem cells may serve as a potential treatment to ameliorate brain injury in hypoxic-ischemic encephalopathy patients.


Assuntos
Hipóxia-Isquemia Encefálica , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais/metabolismo , Neuroproteção , Cordão Umbilical/metabolismo , Animais , Modelos Animais de Doenças , Xenoenxertos , Humanos , Hipóxia-Isquemia Encefálica/metabolismo , Hipóxia-Isquemia Encefálica/patologia , Hipóxia-Isquemia Encefálica/terapia , Células-Tronco Mesenquimais/patologia , Ratos , Ratos Sprague-Dawley , Cordão Umbilical/patologia
7.
Exp Cell Res ; 379(1): 65-72, 2019 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-30898547

RESUMO

Olfactory ensheathing cells (OECs) are ideal candidates for cell-based therapies aimed at repairing spinal cord injury (SCI). Accurate targeting of OECs to the lesion site is critical to reconstructing the impaired nervous system. However, the key factors guiding the homing of transplanted OECs to the damaged area after SCI are still unclear. Here, we demonstrate that lysophosphatidic acid (LPA) can significantly facilitate the homing of OECs after SCI in rats. First, we found that OECs exhibited a robust chemotaxis response to LPA in vitro, with LPAR1 being predominant receptor expressed on OECs. We further found that ß-catenin signaling plays an important role in LPA-induced OEC migration. Moreover, silencing LPAR1 not only abolished the migration of OECs but also prevented ERK1/2 phosphorylation and ß-catenin activation, suggesting that LPAR1 ligation serves to activate the ERK1/2 and ß-catenin pathways in LPA-induced OEC chemotactic migration. Finally, cell transplantation experiments confirmed that endogenous LPA, which was observed to be produced at the lesion site after SCI in rat, is a key chemokine that facilitates OEC migration to the injury center. Collectively, our data provide a further description of the homing effects of LPA and a mechanism by which transplanted OECs migrate to the injured area after SCI in rats.


Assuntos
Lisofosfolipídeos/metabolismo , Bulbo Olfatório/metabolismo , Traumatismos da Medula Espinal/metabolismo , Traumatismos da Medula Espinal/terapia , Animais , Movimento Celular/fisiologia , Transplante de Células/métodos , Células Cultivadas , Sistema de Sinalização das MAP Quinases/fisiologia , Bulbo Olfatório/citologia , Fosforilação/fisiologia , Ratos , Ratos Sprague-Dawley , Receptores de Ácidos Lisofosfatídicos/metabolismo , Transdução de Sinais/fisiologia , Medula Espinal/citologia , Medula Espinal/metabolismo , beta Catenina/metabolismo
8.
Stem Cell Rev Rep ; 15(1): 3-12, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30328004

RESUMO

Mesenchymal stem cells (MSCs) represent a promising source of cell-based therapies for treatment of a wide variety of injuries and diseases. Their tropism and migration to the damaged sites, which are elicited by cytokines secreted from tissues around pathology, are the prerequisite for tissue repair and regeneration. Better understanding of the elicited-migration of MSCs and discovering conditions that elevate their migration ability, will help to increase their homing to pathologies and improve therapeutic efficacy. It is increasingly recognized that microRNAs are important regulators of cell migration. Here we summarize current understanding of the microRNA-regulated migration of MSCs.


Assuntos
Movimento Celular/genética , Células-Tronco Mesenquimais/citologia , MicroRNAs/metabolismo , Animais , Junções Célula-Matriz , Exossomos/metabolismo , Humanos , MicroRNAs/genética , Transdução de Sinais
9.
Sci Rep ; 8(1): 1986, 2018 01 31.
Artigo em Inglês | MEDLINE | ID: mdl-29386586

RESUMO

Thyroid stimulating hormone (TSH) stimulates the secretion of thyroid hormones by binding the TSH receptor (TSHR). TSHR is well-known to be expressed in thyroid tissue, excepting it, TSHR has also been expressed in many other tissues. In this study, we have examined the expression of TSHR in rat pancreatic islets and evaluated the role of TSH in regulating pancreas-specific gene expression. TSHR was confirmed to be expressed in rodent pancreatic islets and its cell line, INS-1 cells. TSH directly affected the glucose uptake in INS cells by up-regulating the expression of GLUT2, and furthermore this process was blocked by SB203580, the specific inhibitor of the p38 MAPK signaling pathway. Similarly, TSH stimulated GLUT2 promoter activity, while both a dominant-negative p38MAPK α isoform (p38MAPK α-DN) and the specific inhibitor for p38MAPK α abolished the stimulatory effect of TSH on GLUT2 promoter activity. Finally, INS-1 cells treated with TSH showed increased protein level of glucokinase and enhanced glucose-stimulated insulin secretion. Together, these results confirm that TSHR is expressed in INS-1 cells and rat pancreatic islets, and suggest that activation of the p38MAPK α might be required for TSH-induced GLUT2 gene transcription in pancreatic ß cells.


Assuntos
Transportador de Glucose Tipo 2/metabolismo , Células Secretoras de Insulina/metabolismo , Tireotropina/farmacologia , Animais , Linhagem Celular , Glucoquinase/metabolismo , Glucose/metabolismo , Transportador de Glucose Tipo 2/genética , Insulina/metabolismo , Células Secretoras de Insulina/efeitos dos fármacos , Regiões Promotoras Genéticas/genética , Ratos Wistar , Receptores da Tireotropina/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
10.
Cell Tissue Res ; 372(1): 99-114, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29322249

RESUMO

The migration of mesenchymal stem cells (MSCs) is critical for their use in cell-based therapies. Accumulating evidence suggests that microRNAs are important regulators of MSC migration. Here, we report that the expression of miR-375 was downregulated in MSCs treated with hepatocyte growth factor (HGF), which strongly stimulates the migration of these cells. Overexpression of miR-375 decreased the transfilter migration and the migration velocity of MSCs triggered by HGF. In our efforts to determine the mechanism by which miR-375 affects MSC migration, we found that miR-375 significantly inhibited the activation of Akt by downregulating its phosphorylation at T308 and S473, but had no effect on the activity of mitogen-activated protein kinases. Further, we showed that 3'phosphoinositide-dependent protein kinase-1 (PDK1), an upstream kinase necessary for full activation of Akt, was negatively regulated by miR-375 at the protein level. Moreover, miR-375 suppressed the phosphorylation of focal adhesion kinase (FAK) and paxillin, two important regulators of focal adhesion (FA) assembly and turnover, and decreased the number of FAs at cell periphery. Taken together, our results demonstrate that miR-375 inhibits HGF-elicited migration of MSCs through downregulating the expression of PDK1 and suppressing the activation of Akt, as well as influencing the tyrosine phosphorylation of FAK and paxillin and FA periphery distribution.


Assuntos
Movimento Celular/efeitos dos fármacos , Regulação para Baixo , Fator de Crescimento de Hepatócito/farmacologia , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/metabolismo , MicroRNAs/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais , Proteínas Quinases Dependentes de 3-Fosfoinositídeo/metabolismo , Animais , Sequência de Bases , Regulação para Baixo/efeitos dos fármacos , Proteína-Tirosina Quinases de Adesão Focal/metabolismo , Adesões Focais/efeitos dos fármacos , Adesões Focais/metabolismo , Células HEK293 , Humanos , Masculino , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/enzimologia , MicroRNAs/genética , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Modelos Biológicos , Paxilina/metabolismo , Fosforilação , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacos
11.
Sci Rep ; 7(1): 10013, 2017 08 30.
Artigo em Inglês | MEDLINE | ID: mdl-28855566

RESUMO

Directed migration of the transplanted mesenchymal stem cells (MSCs) to the lesion sites plays a pivotal role in the efficacy of cell-based therapy. Our previous study demonstrates that MSCs under varying neural differentiation states possess different migratory capacities in response to chemoattractants. However, the underlying mechanism has not been fully addressed. Herein, we show that the assembly and turnover of focal adhesions, the phosphorylation of FAK and paxillin, and the reorganisation of F-actin in MSCs are closely related to their differentiation states in response to SDF-1α. Upon SDF-1α stimulation, FAs turnover more rapidly with the most obvious reduction in the existing time of FAs in MSCs of 24-h preinduction that exhibit the most effective migration towards SDF-1α. Further, we confirm that PI3K/Akt and MAPK pathways participate in the regulation of SDF-1α-induced cell migration and FA assembly, and moreover, that the regulatory effects vary greatly depending on the differentiation states. Collectively, these results demonstrate that FA assembly and turnover, which is accompanied with F-actin reorganisation in response to SDF-1α, correlates closely with the differentiation states of MSCs, which might contribute to the different chemotactic responses of these cells, and thus help develop new strategy to improve the efficacy of MSCs-based therapy.


Assuntos
Quimiocina CXCL12/metabolismo , Adesões Focais/metabolismo , Células-Tronco Mesenquimais/parasitologia , Actinas/metabolismo , Animais , Movimento Celular , Quimiotaxia , Quinase 1 de Adesão Focal/metabolismo , Paxilina/metabolismo , Fosforilação , Multimerização Proteica , Processamento de Proteína Pós-Traducional , Ratos Sprague-Dawley , Transdução de Sinais
12.
Stem Cells Int ; 2017: 5251313, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28630630

RESUMO

Spinal cord injury (SCI) represents one of the most complicated and heterogeneous pathological processes of central nervous system (CNS) impairments, which is still beyond functional regeneration. Transplantation of mesenchymal stem cells (MSCs) has been shown to promote the repair of the injured spinal cord tissues in animal models, and therefore, there is much interest in the clinical use of these cells. However, many questions which are essential to improve the therapy effects remain unanswered. For instance, the functional roles and related molecular regulatory mechanisms of MSCs in vivo are not yet completely determined. It is important for transplanted cells to migrate into the injured tissue, to survive and undergo neural differentiation, or to play neural protection roles by various mechanisms after SCI. In this review, we will focus on some of the recent knowledge about the biological behavior and function of MSCs in SCI. Meanwhile, we highlight the function of biomaterials to direct the behavior of MSCs based on our series of work on silk fibroin biomaterials and attempt to emphasize combinational strategies such as tissue engineering for functional improvement of SCI.

13.
Am J Physiol Cell Physiol ; 313(1): C80-C93, 2017 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-28424168

RESUMO

Mesenchymal stem cells (MSCs) have the potential to treat various tissue damages, but the very limited number of cells that migrate to the damaged region strongly restricts their therapeutic applications. Full understanding of mechanisms regulating MSC migration will help to improve their migration ability and therapeutic effects. Increasing evidence shows that microRNAs play important roles in the regulation of MSC migration. In the present study, we reported that miR-9-5p was upregulated in hepatocyte growth factor -treated MSCs and in MSCs with high migration ability. Overexpression of miR-9-5p promoted MSC migration, whereas inhibition of endogenous miR-9-5p decreased MSC migration. To elucidate the underlying mechanism, we screened the target genes of miR-9-5p and report for the first time that CK1α and GSK3ß, two inhibitors of ß-catenin signaling pathway, were direct targets of miR-9-5p in MSCs and that overexpression of miR-9-5p upregulated ß-catenin signaling pathway. In line with these data, inhibition of ß-catenin signaling pathway by FH535 decreased the miR-9-5p-promoted migration of MSCs, while activation of ß-catenin signaling pathway by LiCl rescued the impaired migration of MSCs triggered by miR-9-5p inhibitor. Furthermore, the formation and distribution of focal adhesions as well as the reorganization of F-actin were affected by the expression of miR-9-5p. Collectively, these results demonstrate that miR-9-5p promotes MSC migration by upregulating ß-catenin signaling pathway, shedding light on the optimization of MSCs for cell replacement therapy through manipulating the expression level of miR-9-5p.


Assuntos
Células-Tronco Mesenquimais/metabolismo , MicroRNAs/genética , Neurônios/metabolismo , beta Catenina/genética , Actinas/genética , Actinas/metabolismo , Animais , Caseína Quinase I/genética , Caseína Quinase I/metabolismo , Diferenciação Celular/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Adesões Focais/efeitos dos fármacos , Adesões Focais/metabolismo , Regulação da Expressão Gênica , Glicogênio Sintase Quinase 3 beta/genética , Glicogênio Sintase Quinase 3 beta/metabolismo , Fator de Crescimento de Hepatócito/farmacologia , Cloreto de Lítio/farmacologia , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/efeitos dos fármacos , MicroRNAs/metabolismo , Neurônios/citologia , Neurônios/efeitos dos fármacos , Cultura Primária de Células , Ratos , Ratos Sprague-Dawley , Transdução de Sinais , Sulfonamidas/farmacologia , Transfecção , beta Catenina/metabolismo
14.
Eur J Cell Biol ; 95(9): 342-53, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27377850

RESUMO

Mesenchymal stem cells (MSCs) exhibit the potential to repair a wide variety of injured adult tissues. The migration capability of MSCs is an important determinant of the efficiency of MSC transplant therapy. MicroRNAs (miRNAs) are increasingly implicated in regulating the migration of MSCs. Herein, we show that the expression of miR-124 was downregulated in rat MSCs (rMSCs) treated with hepatocyte growth factor (HGF). Overexpression of miR-124 significantly reduced the chemotactic migration of rMSCs toward HGF, while inhibition of endogenous miR-124 promoted the chemotactic migration. A further study revealed that miR-124 directly targeted FZD4 and LRP6, which encode a receptor and co-receptor of the Wnt/ß-catenin signaling pathway, respectively, thus reducing the activity of this signaling. Consistently, activation of the Wnt/ß-catenin signaling pathway by LiCl and ΔN89ß-catenin rescued the inhibitory effect of miR-124 on the chemotactic migration of rMSCs toward HGF, while inhibition of Wnt/ß-catenin signaling by FH535 abrogated the enhanced chemotactic response achieved by the miR-124 inhibitor. Collectively, our study demonstrates that miR-124 downregulates Wnt/ß-catenin signaling via targeting FZD4 and LRP6 and thus suppresses the chemotactic migration of rMSCs toward HGF.


Assuntos
Fator de Crescimento de Hepatócito/farmacologia , Células-Tronco Mesenquimais/citologia , MicroRNAs/biossíntese , Via de Sinalização Wnt/genética , Animais , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Movimento Celular/genética , Quimiotaxia/genética , Regulação para Baixo , Células HEK293 , Humanos , Masculino , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/metabolismo , MicroRNAs/administração & dosagem , MicroRNAs/antagonistas & inibidores , MicroRNAs/genética , Ratos , Ratos Sprague-Dawley , Transfecção , Via de Sinalização Wnt/efeitos dos fármacos
15.
Sci Rep ; 6: 27724, 2016 06 14.
Artigo em Inglês | MEDLINE | ID: mdl-27296555

RESUMO

Mesenchymal stem cells (MSCs) can be used to treat many diseases, including spinal cord injury (SCI). Treatment relies mostly on the precise navigation of cells to the injury site for rebuilding the damaged spinal cord. However, the key factors guiding MSCs to the epicenter of SCI remain unknown. Here, we demonstrated that calcitonin gene-related peptide (CGRP), a neural peptide synthesized in spinal cord, can dramatically aid the homing of human umbilical cord mesenchymal stem cells (HUMSCs) in spinal cord-transected SCI rats. First, HUMSCs exhibited chemotactic responses in vitro to CGRP. By time-lapse video analysis, increased chemotactic index (CMI), forward migration index (FMI) and speed contributed to this observed migration. Then, through enzyme immunoassay, higher CGRP concentrations at the lesion site were observed after injury. The release of CGRP directed HUMSCs to the injury site, which was suppressed by CGRP 8-37, a CGRP antagonist. We also verified that the PI3K/Akt and p38MAPK signaling pathways played a critical role in the CGRP-induced chemotactic migration of HUMSCs. Collectively, our data reveal that CGRP is a key chemokine that helps HUMSCs migrate to the lesion site and thereby can be used as a model molecule to study MSCs homing after SCI.


Assuntos
Peptídeo Relacionado com Gene de Calcitonina/metabolismo , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais/citologia , Traumatismos da Medula Espinal/terapia , Animais , Apoptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Forma Celular/efeitos dos fármacos , Quimiotaxia/efeitos dos fármacos , Feminino , Humanos , Imuno-Histoquímica , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/metabolismo , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacos , Medula Espinal/patologia , Traumatismos da Medula Espinal/patologia
16.
J Cell Biochem ; 117(6): 1370-83, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26538296

RESUMO

The chemotactic migration of mesenchymal stem cells (MSCs) is fundamental for their use in cell-based therapies, but little is known about the molecular mechanisms that regulate their directed migration. MicroRNAs (miRNAs) participate in the regulation of a large variety of cellular processes. However, their roles in regulating the responses of MSCs to hepatocyte growth factor (HGF) remain elusive. Here, we found that microRNA-221 (miR-221) and microRNA-26b (miR-26b) were upregulated in MSCs subjected to HGF. Overexpression of miR-221 or miR-26b enhanced MSC migration through activation of PI3K/Akt signaling. Phosphatase and tensin homolog deleted on chromosome ten (PTEN) was identified as a potential target of miR-221 and miR-26b; overexpression of miR-221 or miR-26b decreased PTEN expression at both mRNA and protein levels. Overexpression of miR-221 or miR-26b in MSCs increased the phosphorylation of focal adhesion kinase (FAK), a downstream effector of PTEN, which regulates cell migration through assembly and distribution of focal adhesions (FAs), and more dot-like FAs were localized at the periphery of these cells. Altering miR-221 or miR-26b expression influenced the directed migration of MSCs toward HGF. Inhibition of miR-221 or miR-26b suppressed the phosphorylation of Akt and FAK and upregulated PTEN expression, which was partly restored by HGF treatment. Collectively, these results demonstrate that miR-221 and miR-26b participate in regulating the chemotactic response of MSCs toward HGF.


Assuntos
Quinase 1 de Adesão Focal/metabolismo , Fator de Crescimento de Hepatócito/farmacologia , Células-Tronco Mesenquimais/citologia , MicroRNAs/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Animais , Movimento Celular/efeitos dos fármacos , Quimiotaxia/efeitos dos fármacos , Perfilação da Expressão Gênica , Regulação da Expressão Gênica/efeitos dos fármacos , Células-Tronco Mesenquimais/efeitos dos fármacos , Ratos , Transdução de Sinais
17.
World J Hepatol ; 7(24): 2535-42, 2015 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-26527170

RESUMO

Infection by hepatitis C virus (HCV), a plus-stranded RNA virus that can cause cirrhosis and hepatocellular carcinoma, is one of the major health problems in the world. HCV infection is considered as a multi-step complex process and correlated with abnormal metabolism of lipoprotein. In addition, virus attacks hepatocytes by the initial attaching viral envelop glycoprotein E1/E2 to receptors of lipoproteins on host cells. With the development of HCV model system, mechanisms of HCV cell entry through lipoprotein uptake and its receptor have been extensively studied in detail. Here we summarize recent knowledge about the role of lipoprotein receptors, scavenger receptor class B type I and low-density lipoprotein receptor in the entry of HCV, providing a foundation of novel targeting therapeutic tools against HCV infection.

18.
J Cell Physiol ; 230(11): 2728-42, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25820249

RESUMO

Mesenchymal stem cells (MSCs) hold great promise in neural regeneration, due to their intrinsic neuronal potential and migratory tropism to damaged nervous tissues. However, the chemotactic signals mediating the migration of MSCs remain poorly understood. Here, we investigated the regulatory roles for focal adhesion kinase (FAK) and Rac1 in vascular endothelial growth factor (VEGF)-stimulated migration of MSCs in neural differentiation. We found that MSCs in various differentiation states show significant different chemotactic responses to VEGF and cells in 24-h preinduction state possess the highest migration speed and efficiency. FAK, as the downstream signaling molecule, is involved in the VEGF-induced migration by regulating the assembly and distribution of focal adhesions (FAs) and reorganization of F-actin. The features of FAs and cytoskeletons and the ability of lamellipodia formation are closely related to the neural differentiation states of MSCs. VEGF promotes FA formation with an asymmetric distribution of FAs and induces the activation of Y397-FAK and Y31/118-paxillin of undifferentiated and 24-h preinduced MSCs in a time-dependent manner. Inhibition of FAK by PF-228 or expressing FAK-Y397F mutant impairs the dynamics of FAs in MSCs during VEGF-induced migration. Furthermore, Rac1 regulates FA formation in a FAK-dependent manner. Overexpression of constitutive activated mutants of Rac1 increases the number of FAs in undifferentiated and 24-h preinduced MSCs, while VEGF-induced increase of FA formation is decreased by inhibiting FAK by PF-228. Collectively, these results demonstrate that FAK and Rac1 signalings coordinately regulate the dynamics of FAs during VEGF-induced migration of MSCs in varying neural differentiation states.


Assuntos
Diferenciação Celular/genética , Movimento Celular/genética , Proteína-Tirosina Quinases de Adesão Focal/biossíntese , Fator A de Crescimento do Endotélio Vascular/metabolismo , Proteínas rac1 de Ligação ao GTP/biossíntese , Actinas/metabolismo , Movimento Celular/efeitos dos fármacos , Proteína-Tirosina Quinases de Adesão Focal/antagonistas & inibidores , Adesões Focais/efeitos dos fármacos , Adesões Focais/genética , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Humanos , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/metabolismo , Regeneração Nervosa/genética , Neurônios/citologia , Neurônios/metabolismo , Quinolonas/administração & dosagem , Transdução de Sinais/efeitos dos fármacos , Sulfonas/administração & dosagem , Fator A de Crescimento do Endotélio Vascular/administração & dosagem , Proteínas rac1 de Ligação ao GTP/metabolismo
19.
Cell Mol Neurobiol ; 34(7): 1047-58, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25038638

RESUMO

Mesenchymal stem cells (MSCs) are proposed as a promising source for cell-based therapies in neural disease. Although increasing numbers of studies have been devoted to the delineation of factors involved in the migration of MSCs, the relationship between the chemotactic response and the differentiation status of these cells is still unclear. In the present study, we demonstrated that MSCs in varying neural differentiation states display various chemotactic responses to stromal cell-derived factor-1α (SDF-1α). The chemotactic responses of MSCs under different differentiation stages in response to SDF-1α were analyzed by Boyden chamber, and the results showed that cells of undifferentiation, 24-h preinduction, 5-h induction, and 18-h maintenance states displayed a stronger chemotactic response to SDF-1α, while 48-h maintenance did not. Further, we found that the phosphorylation levels of PI3K/Akt, ERK1/2, SAPK/JNK, and p38MAPK are closely related to the differentiation states of MSCs subjected to SDF-1α, and finally, inhibition of SAPK/JNK signaling significantly attenuates SDF-1α-stimulated transfilter migration of MSCs of undifferentiation, 24-h preinduction, 18-h maintenance, and 48-h maintenance, but not MSCs of 5-h induction. Meanwhile, interference with PI3K/Akt, p38MAPK, or ERK1/2 signaling prevents only cells at certain differentiation state from migrating in response to SDF-1α. Collectively, these results demonstrate that MSCs in varying neural differentiation states have different migratory capacities, thereby illuminating optimization of the therapeutic potential of MSCs to be used for neural regeneration after injury.


Assuntos
Diferenciação Celular/efeitos dos fármacos , Quimiocina CXCL12/farmacologia , Quimiotaxia/efeitos dos fármacos , Células-Tronco Mesenquimais/citologia , Neurônios/citologia , Animais , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/enzimologia , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Neurônios/efeitos dos fármacos , Neurônios/enzimologia , Fosfatidilinositol 3-Quinases/metabolismo , Fosforilação/efeitos dos fármacos , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos Sprague-Dawley
20.
J Mol Neurosci ; 54(2): 219-33, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24659235

RESUMO

Chemotaxis of neural stem/progenitor cells (NSCs) is regulated by a variety of factors, and much effort has been devoted to the delineation of factors that are involved in NSC migration. However, the relationship between NSC chemotactic migration and differentiation remains uncharacterized. In the present study, by comparing the transfilter migration rate, single-cell migration speed, and directional efficiency of NSCs in stromal cell-derived factor-1 alpha (SDF-1α)-induced Boyden chamber and Dunn chamber chemotaxis assays, we demonstrate that NSCs in varying differentiation stages possess different migratory capacity. Furthermore, F-actin microfilament reorganization upon stimulation varies greatly among separate differentiation states. We show that signaling pathways involved in NSC migration, such as PI3K/Akt and mitogen-activated protein kinase (MAPK) (ERK1/2, JNK, and p38 MAPK) pathways, are differentially activated by SDF-1α among each NSC differentiation stages, and the extent to which these pathways participate in cell chemotaxis exhibits a differentiation stage-dependent manner. Taken together, these results suggest that the differentiation of NSCs influences their chemotactic responses to SDF-1α, providing new insight into the optimization of the therapeutic efficacy of NSCs for neural regeneration and nerve repair after injury.


Assuntos
Quimiocina CXCL12/farmacologia , Quimiotaxia , Células-Tronco Neurais/fisiologia , Neurogênese , Actinas/metabolismo , Animais , Linhagem Celular , Sistema de Sinalização das MAP Quinases , Camundongos , Células-Tronco Neurais/citologia , Células-Tronco Neurais/efeitos dos fármacos , Células-Tronco Neurais/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo
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