Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 307
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Nature ; 604(7907): 763-770, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35418678

RESUMO

Adhesion G-protein-coupled receptors (aGPCRs) are important for organogenesis, neurodevelopment, reproduction and other processes1-6. Many aGPCRs are activated by a conserved internal (tethered) agonist sequence known as the Stachel sequence7-12. Here, we report the cryogenic electron microscopy (cryo-EM) structures of two aGPCRs in complex with Gs: GPR133 and GPR114. The structures indicate that the Stachel sequences of both receptors assume an α-helical-bulge-ß-sheet structure and insert into a binding site formed by the transmembrane domain (TMD). A hydrophobic interaction motif (HIM) within the Stachel sequence mediates most of the intramolecular interactions with the TMD. Combined with the cryo-EM structures, biochemical characterization of the HIM motif provides insight into the cross-reactivity and selectivity of the Stachel sequences. Two interconnected mechanisms, the sensing of Stachel sequences by the conserved 'toggle switch' W6.53 and the constitution of a hydrogen-bond network formed by Q7.49/Y7.49 and the P6.47/V6.47φφG6.50 motif (φ indicates a hydrophobic residue), are important in Stachel sequence-mediated receptor activation and Gs coupling. Notably, this network stabilizes kink formation in TM helices 6 and 7 (TM6 and TM7, respectively). A common Gs-binding interface is observed between the two aGPCRs, and GPR114 has an extended TM7 that forms unique interactions with Gs. Our structures reveal the detailed mechanisms of aGPCR activation by Stachel sequences and their Gs coupling.


Assuntos
Peptídeos , Receptores Acoplados a Proteínas G , Sítios de Ligação , Microscopia Crioeletrônica , Domínios Proteicos , Estrutura Secundária de Proteína , Receptores Acoplados a Proteínas G/metabolismo , Relação Estrutura-Atividade
2.
Stem Cells ; 42(7): 593-606, 2024 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-38655770

RESUMO

Cycling myeloid cells (CMCs) are often detected from various tissues using single-cell RNA sequencing (scRNA-seq) datasets, however, their research value was not noticed before. For the first time, our study preliminarily revealed the origin, differentiation, and roles of CMCs in physiological processes. Particularly, subgroup a of cycling myeloid cells (aCMCs) were conclusively identified as belonging to a specific cell type. In an active state, aCMCs rapidly proliferate during the early stages of an embryonic development. With an individual maturing, most aCMCs differentiate into specialized cells, while a small portion of them enter an inactive or dormant state. Under pathological conditions, aCMCs restore their proliferative and differentiation capacities via activation or revival. The present study has set the stage for future research on CMCs by linking them with progenitors of immune cells, and provided a crucial starting point to understand the origin, differentiation, and roles of CMCs in various physiological and pathological processes, particularly those related to traumatic injury, cancer, and pathogen infection, leading to develop targeted therapies or interventions.


Assuntos
Diferenciação Celular , Células Mieloides , Análise de Célula Única , Células Mieloides/metabolismo , Análise de Célula Única/métodos , Animais , Diferenciação Celular/genética , RNA-Seq/métodos , Humanos , Camundongos , Análise de Sequência de RNA/métodos , Ciclo Celular/genética , Proliferação de Células/genética , Análise da Expressão Gênica de Célula Única
3.
Proc Natl Acad Sci U S A ; 119(29): e2117054119, 2022 07 19.
Artigo em Inglês | MEDLINE | ID: mdl-35858343

RESUMO

The G protein-coupled bile acid receptor (GPBAR) is the membrane receptor for bile acids and a driving force of the liver-bile acid-microbiota-organ axis to regulate metabolism and other pathophysiological processes. Although GPBAR is an important therapeutic target for a spectrum of metabolic and neurodegenerative diseases, its activation has also been found to be linked to carcinogenesis, leading to potential side effects. Here, via functional screening, we found that two specific GPBAR agonists, R399 and INT-777, demonstrated strikingly different regulatory effects on the growth and apoptosis of non-small cell lung cancer (NSCLC) cells both in vitro and in vivo. Further mechanistic investigation showed that R399-induced GPBAR activation displayed an obvious bias for ß-arrestin 1 signaling, thus promoting YAP signaling activation to stimulate cell proliferation. Conversely, INT-777 preferentially activated GPBAR-Gs signaling, thus inactivating YAP to inhibit cell proliferation and induce apoptosis. Phosphorylation of GPBAR by GRK2 at S310/S321/S323/S324 sites contributed to R399-induced GPBAR-ß-arrestin 1 association. The cryoelectron microscopy (cryo-EM) structure of the R399-bound GPBAR-Gs complex enabled us to identify key interaction residues and pivotal conformational changes in GPBAR responsible for the arrestin signaling bias and cancer cell proliferation. In summary, we demonstrate that different agonists can regulate distinct functions of cell growth and apoptosis through biased GPBAR signaling and control of YAP activity in a NSCLC cell model. The delineated mechanism and structural basis may facilitate the rational design of GPBAR-targeting drugs with both metabolic and anticancer benefits.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Proteínas de Ciclo Celular , Neoplasias Pulmonares , Receptores Acoplados a Proteínas G , Fatores de Transcrição , Ácidos e Sais Biliares/metabolismo , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Carcinoma Pulmonar de Células não Pequenas/patologia , Proteínas de Ciclo Celular/metabolismo , Ácidos Cólicos/farmacologia , Microscopia Crioeletrônica , Humanos , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Receptores Acoplados a Proteínas G/agonistas , Receptores Acoplados a Proteínas G/química , Receptores Acoplados a Proteínas G/metabolismo , Fatores de Transcrição/metabolismo , beta-Arrestina 1/metabolismo
4.
Proc Natl Acad Sci U S A ; 119(15): e2117004119, 2022 04 12.
Artigo em Inglês | MEDLINE | ID: mdl-35394864

RESUMO

GPR126 is a member of the adhesion G protein-coupled receptors (aGPCRs) that is essential for the normal development of diverse tissues, and its mutations are implicated in various pathological processes. Here, through screening 34 steroid hormones and their derivatives for cAMP production, we found that progesterone (P4) and 17-hydroxyprogesterone (17OHP) could specifically activate GPR126 and trigger its downstream Gi signaling by binding to the ligand pocket in the seven-transmembrane domain of the C-terminal fragment of GPR126. A detailed mutagenesis screening according to a computational simulated structure model indicated that K1001ECL2 and F1012ECL2 are key residues that specifically recognize 17OHP but not progesterone. Finally, functional analysis revealed that progesterone-triggered GPR126 activation promoted cell growth in vitro and tumorigenesis in vivo, which involved Gi-SRC pathways in a triple-negative breast cancer model. Collectively, our work identified a membrane receptor for progesterone/17OHP and delineated the mechanisms by which GPR126 participated in potential tumor progression in triple-negative breast cancer, which will enrich our understanding of the functions and working mechanisms of both the aGPCR member GPR126 and the steroid hormone progesterone.


Assuntos
Progesterona , Receptores Acoplados a Proteínas G , Receptores de Progesterona , Neoplasias de Mama Triplo Negativas , 17-alfa-Hidroxiprogesterona/metabolismo , Linhagem Celular Tumoral , Humanos , Progesterona/metabolismo , Receptores Acoplados a Proteínas G/química , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismo , Receptores de Progesterona/genética , Receptores de Progesterona/metabolismo , Transdução de Sinais , Neoplasias de Mama Triplo Negativas/genética , Neoplasias de Mama Triplo Negativas/metabolismo
5.
Nano Lett ; 24(11): 3548-3556, 2024 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-38457277

RESUMO

After spinal cord injury (SCI), successive systemic administration of microtubule-stabilizing agents has been shown to promote axon regeneration. However, this approach is limited by poor drug bioavailability, especially given the rapid restoration of the blood-spinal cord barrier. There is a pressing need for long-acting formulations of microtubule-stabilizing agents in treating SCI. Here, we conjugated the antioxidant idebenone with microtubule-stabilizing paclitaxel to create a heterodimeric paclitaxel-idebenone prodrug via an acid-activatable, self-immolative ketal linker and then fabricated it into chondroitin sulfate proteoglycan-binding nanomedicine, enabling drug retention within the spinal cord for at least 2 weeks and notable enhancement in hindlimb motor function and axon regeneration after a single intraspinal administration. Additional investigations uncovered that idebenone can suppress the activation of microglia and neuronal ferroptosis, thereby amplifying the therapeutic effect of paclitaxel. This prodrug-based nanomedicine simultaneously accomplishes neuroprotection and axon regeneration, offering a promising therapeutic strategy for SCI.


Assuntos
Axônios , Traumatismos da Medula Espinal , Ubiquinona/análogos & derivados , Animais , Paclitaxel/farmacologia , Paclitaxel/uso terapêutico , Excipientes/farmacologia , Excipientes/uso terapêutico , Nanomedicina , Regeneração Nervosa , Traumatismos da Medula Espinal/terapia
6.
BMC Med ; 22(1): 167, 2024 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-38637815

RESUMO

BACKGROUND: The prevalence of depression among people with chronic pain remains unclear due to the heterogeneity of study samples and definitions of depression. We aimed to identify sources of variation in the prevalence of depression among people with chronic pain and generate clinical prediction models to estimate the probability of depression among individuals with chronic pain. METHODS: Participants were from the UK Biobank. The primary outcome was a "lifetime" history of depression. The model's performance was evaluated using discrimination (optimism-corrected C statistic) and calibration (calibration plot). RESULTS: Analyses included 24,405 patients with chronic pain (mean age 64.1 years). Among participants with chronic widespread pain, the prevalence of having a "lifetime" history of depression was 45.7% and varied (25.0-66.7%) depending on patient characteristics. The final clinical prediction model (optimism-corrected C statistic: 0.66; good calibration on the calibration plot) included age, BMI, smoking status, physical activity, socioeconomic status, gender, history of asthma, history of heart failure, and history of peripheral artery disease. Among participants with chronic regional pain, the prevalence of having a "lifetime" history of depression was 30.2% and varied (21.4-70.6%) depending on patient characteristics. The final clinical prediction model (optimism-corrected C statistic: 0.65; good calibration on the calibration plot) included age, gender, nature of pain, smoking status, regular opioid use, history of asthma, pain location that bothers you most, and BMI. CONCLUSIONS: There was substantial variability in the prevalence of depression among patients with chronic pain. Clinically relevant factors were selected to develop prediction models. Clinicians can use these models to assess patients' treatment needs. These predictors are convenient to collect during daily practice, making it easy for busy clinicians to use them.


Assuntos
Asma , Dor Crônica , Adulto , Humanos , Pessoa de Meia-Idade , Dor Crônica/epidemiologia , Modelos Estatísticos , Prevalência , Depressão/epidemiologia , Bancos de Espécimes Biológicos , Biobanco do Reino Unido , Prognóstico
7.
J Transl Med ; 21(1): 511, 2023 07 28.
Artigo em Inglês | MEDLINE | ID: mdl-37507810

RESUMO

BACKGROUND: Preinjury of peripheral nerves triggers dorsal root ganglia (DRG) axon regeneration, a biological change that is more pronounced in young mice than in old mice, but the complex mechanism has not been clearly explained. Here, we aim to gain insight into the mechanisms of axon regeneration after conditioning lesion in different age groups of mice, thereby providing effective therapeutic targets for central nervous system (CNS) injury. METHODS: The microarray GSE58982 and GSE96051 were downloaded and analyzed to identify differentially expressed genes (DEGs). The protein-protein interaction (PPI) network, the miRNA-TF-target gene network, and the drug-hub gene network of conditioning lesion were constructed. The L4 and L5 DRGs, which were previously axotomized by the sciatic nerve conditioning lesions, were harvested for qRT-PCR. Furthermore, histological and behavioral tests were performed to assess the therapeutic effects of the candidate drug telmisartan in spinal cord injury (SCI). RESULTS: A total of 693 and 885 DEGs were screened in the old and young mice, respectively. Functional enrichment indicates that shared DEGs are involved in the inflammatory response, innate immune response, and ion transport. QRT-PCR results showed that in DRGs with preinjury of peripheral nerve, Timp1, P2ry6, Nckap1l, Csf1, Ccl9, Anxa1, and C3 were upregulated, while Agtr1a was downregulated. Based on the bioinformatics analysis of DRG after conditioning lesion, Agtr1a was selected as a potential therapeutic target for the SCI treatment. In vivo experiments showed that telmisartan promoted axonal regeneration after SCI by downregulating AGTR1 expression. CONCLUSION: This study provides a comprehensive map of transcriptional changes that discriminate between young and old DRGs in response to injury. The hub genes and their related drugs that may affect the axonal regeneration program after conditioning lesion were identified. These findings revealed the speculative pathogenic mechanism involved in conditioning-dependent regenerative growth and may have translational significance for the development of CNS injury treatment in the future.


Assuntos
MicroRNAs , Traumatismos da Medula Espinal , Camundongos , Animais , Axônios/metabolismo , Axônios/patologia , Regeneração Nervosa/genética , Telmisartan/metabolismo , Telmisartan/farmacologia , MicroRNAs/genética , MicroRNAs/metabolismo , Medula Espinal
8.
BMC Neurosci ; 24(1): 49, 2023 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-37710208

RESUMO

BACKGROUND: Intervertebral disc herniation, degenerative lumbar spinal stenosis, and other lumbar spine diseases can occur across most age groups. MRI examination is the most commonly used detection method for lumbar spine lesions with its good soft tissue image resolution. However, the diagnosis accuracy is highly dependent on the experience of the diagnostician, leading to subjective errors caused by diagnosticians or differences in diagnostic criteria for multi-center studies in different hospitals, and inefficient diagnosis. These factors necessitate the standardized interpretation and automated classification of lumbar spine MRI to achieve objective consistency. In this research, a deep learning network based on SAFNet is proposed to solve the above challenges. METHODS: In this research, low-level features, mid-level features, and high-level features of spine MRI are extracted. ASPP is used to process the high-level features. The multi-scale feature fusion method is used to increase the scene perception ability of the low-level features and mid-level features. The high-level features are further processed using global adaptive pooling and Sigmoid function to obtain new high-level features. The processed high-level features are then point-multiplied with the mid-level features and low-level features to obtain new high-level features. The new high-level features, low-level features, and mid-level features are all sampled to the same size and concatenated in the channel dimension to output the final result. RESULTS: The DSC of SAFNet for segmenting 17 vertebral structures among 5 folds are 79.46 ± 4.63%, 78.82 ± 7.97%, 81.32 ± 3.45%, 80.56 ± 5.47%, and 80.83 ± 3.48%, with an average DSC of 80.32 ± 5.00%. The average DSC was 80.32 ± 5.00%. Compared to existing methods, our SAFNet provides better segmentation results and has important implications for the diagnosis of spinal and lumbar diseases. CONCLUSIONS: This research proposes SAFNet, a highly accurate and robust spine segmentation deep learning network capable of providing effective anatomical segmentation for diagnostic purposes. The results demonstrate the effectiveness of the proposed method and its potential for improving radiological diagnosis accuracy.

9.
J Neuroinflammation ; 19(1): 189, 2022 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-35842640

RESUMO

BACKGROUND: Nafamostat mesylate (nafamostat, NM) is an FDA-approved serine protease inhibitor that exerts anti-neuroinflammation and neuroprotective effects following rat spinal cord injury (SCI). However, clinical translation of nafamostat has been limited by an unclear administration time window and mechanism of action. METHODS: Time to first dose of nafamostat administration was tested on rats after contusive SCI. The optimal time window of nafamostat was screened by evaluating hindlimb locomotion and electrophysiology. As nafamostat is a serine protease inhibitor known to target thrombin, we used argatroban (Arg), a thrombin-specific inhibitor, as a positive control in the time window experiments. Western blot and immunofluorescence of thrombin expression level and its enzymatic activity were assayed at different time points, as well its receptor, the protease activated receptor 1 (PAR1) and downstream protein matrix metalloproteinase-9 (MMP9). Blood-spinal cord barrier (BSCB) permeability leakage indicator Evans Blue and fibrinogen were analyzed along these time points. The infiltration of peripheral inflammatory cell was observed by immunofluorescence. RESULTS: The optimal administration time window of nafamostat was 2-12 h post-injury. Argatroban, the thrombin-specific inhibitor, had a similar pattern. Thrombin expression peaked at 12 h and returned to normal level at 7 days post-SCI. PAR1, the thrombin receptor, and MMP9 were significantly upregulated after SCI. The most significant increase of thrombin expression was detected in vascular endothelial cells (ECs). Nafamostat and argatroban significantly downregulated thrombin and MMP9 expression as well as thrombin activity in the spinal cord. Nafamostat inhibited thrombin enrichment in endothelial cells. Nafamostat administration at 2-12 h after SCI inhibited the leakage of Evans Blue in the epicenter and upregulated tight junction proteins (TJPs) expression. Nafamostat administration 8 h post-SCI effectively inhibited the infiltration of peripheral macrophages and neutrophils to the injury site. CONCLUSIONS: Our study provides preclinical information of nafamostat about the administration time window of 2-12 h post-injury in contusive SCI. We revealed that nafamostat functions through inhibiting the thrombin-mediated BSCB breakdown and subsequent peripheral immune cells infiltration.


Assuntos
Metaloproteinase 9 da Matriz , Traumatismos da Medula Espinal , Animais , Benzamidinas , Barreira Hematoencefálica/metabolismo , Células Endoteliais/metabolismo , Azul Evans/metabolismo , Azul Evans/farmacologia , Guanidinas , Metaloproteinase 9 da Matriz/metabolismo , Ratos , Ratos Sprague-Dawley , Receptor PAR-1/metabolismo , Inibidores de Serina Proteinase/farmacologia , Inibidores de Serina Proteinase/uso terapêutico , Medula Espinal , Traumatismos da Medula Espinal/tratamento farmacológico , Traumatismos da Medula Espinal/metabolismo , Trombina/metabolismo
10.
Biotechnol Lett ; 44(1): 129-142, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34738222

RESUMO

Spinal cord injury (SCI) is catastrophic to humans and society. However, there is currently no effective treatment for SCI. Autophagy is known to serve critical roles in both the physiological and pathological processes of the body, but its facilitatory and/or deleterious effects in SCI are yet to be completely elucidated. This study aimed to use primary Schwann cell-derived exosomes (SCDEs) to treat rats after SCI. In the present study, SCDEs were purified and their efficacy in ameliorating the components of SCI was examined. Using both in vivo and in vitro experiments, it was demonstrated that SCDEs increased autophagy and decreased apoptosis after SCI, which promoted axonal protection and the recovery of motor function. Furthermore, it was discovered that an increased number of SCDEs resulted in a decreased expression level of EGFR, which subsequently inhibited the Akt/mTOR signaling pathway, which upregulated the level of autophagy to ultimately induce microtubule acetylation and polymerization. Collectively, the present study identified that SCDEs could induce axonal protection after SCI by increasing autophagy and decreasing apoptosis, and it was suggested that this may involve the EGFR/Akt/mTOR signaling pathway.


Assuntos
Exossomos , Traumatismos da Medula Espinal , Animais , Apoptose , Autofagia , Exossomos/metabolismo , Ratos , Ratos Sprague-Dawley , Recuperação de Função Fisiológica , Células de Schwann/metabolismo , Medula Espinal , Traumatismos da Medula Espinal/metabolismo
12.
J Neuroinflammation ; 18(1): 172, 2021 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-34372877

RESUMO

BACKGROUND: Traumatic spinal cord injury (SCI) is a severely disabling disease that leads to loss of sensation, motor, and autonomic function. As exosomes have great potential in diagnosis, prognosis, and treatment of SCI because of their ability to easily cross the blood-brain barrier, the function of Schwann cell-derived exosomes (SCDEs) is still largely unknown. METHODS: A T10 spinal cord contusion was established in adult female mice. SCDEs were injected into the tail veins of mice three times a week for 4 weeks after the induction of SCI, and the control group was injected with PBS. High-resolution transmission electron microscope and western blot were used to characterize the SCDEs. Toll-like receptor 2 (TLR2) expression on astrocytes, chondroitin sulfate proteoglycans (CSPGs) deposition and neurological function recovery were measured in the spinal cord tissues of each group by immunofluorescence staining of TLR2, GFAP, CS56, 5-HT, and ß-III-tublin, respectively. TLR2f/f mice were crossed to the GFAP-Cre strain to generate astrocyte specific TLR2 knockout mice (TLR2-/-). Finally, western blot analysis was used to determine the expression of signaling proteins and IKKß inhibitor SC-514 was used to validate the involved signaling pathway. RESULTS: Here, we found that TLR2 increased significantly on astrocytes post-SCI. SCDEs treatment can promote functional recovery and induce the expression of TLR2 on astrocytes accompanied with decreased CSPGs deposition. The specific knockout of TLR2 on astrocytes abolished the decreasing CSPGs deposition and neurological functional recovery post-SCI. In addition, the signaling pathway of NF-κB/PI3K involved in the TLR2 activation was validated by western blot. Furthermore, IKKß inhibitor SC-514 was also used to validate this signaling pathway. CONCLUSION: Thus, our results uncovered that SCDEs can promote functional recovery of mice post-SCI by decreasing the CSPGs deposition via increasing the TLR2 expression on astrocytes through NF-κB/PI3K signaling pathway.


Assuntos
Astrócitos/metabolismo , Proteoglicanas de Sulfatos de Condroitina/metabolismo , Exossomos/metabolismo , Células de Schwann/metabolismo , Traumatismos da Medula Espinal/metabolismo , Receptor 2 Toll-Like/metabolismo , Animais , Modelos Animais de Doenças , Feminino , Proteína Glial Fibrilar Ácida/metabolismo , Camundongos , Camundongos Knockout , Recuperação de Função Fisiológica/fisiologia , Serotonina/metabolismo , Medula Espinal/metabolismo , Receptor 2 Toll-Like/genética , Tubulina (Proteína)/metabolismo
13.
J Cell Physiol ; 235(6): 5171-5181, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-31691285

RESUMO

Nerve damage can lead to movement and sensory dysfunction, with high morbidity and disability rates causing severe burdens on patients, families, and society. DNA methylation is a kind of epigenetics, and a great number of previous studies have demonstrated that DNA methylation plays an important role in the process of nerve regeneration and remodeling. However, compared with the central nervous system, the peripheral nervous system shows stronger recovery after injury, which is related to the complex microenvironment and epigenetic changes occurring at the site of injury. Therefore, what common epigenetic changes between the central and peripheral nervous systems remain to be elucidated. We first screened differential methylation genes after spinal cord injury and sciatic nerve injury using whole-genome bisulfite sequencing and methylated DNA immunoprecipitation sequencing, respectively. Subsequently, a total of 16 genes had the same epigenetic changes after spinal cord injury and sciatic nerve injury. The Gene Ontology analysis and Kyoto Encyclopedia of Genes and Genomes enrichment analysis were performed to identify the critical biological processes and pathways. Furthermore, a protein-protein interaction network analysis indicated that Dnm3, Ntrk3, Smurf1, Dpysl2, Kalrn, Shank1, Dlg2, Arsb, Reln, Bmp5, Numbl, Prickle2, Map6, and Htr7 were the core genes. These outcomes may provide novel insights into the molecular mechanism of the subacute phase of nerve injury. These verified genes can offer potential diagnostic and therapeutic targets for nerve injury.


Assuntos
Metilação de DNA/genética , Traumatismos dos Nervos Periféricos/genética , Neuropatia Ciática/genética , Traumatismos da Medula Espinal/genética , Animais , Microambiente Celular/genética , Epigênese Genética/genética , Regulação da Expressão Gênica/genética , Genoma/genética , Humanos , Masculino , Traumatismos dos Nervos Periféricos/patologia , Mapas de Interação de Proteínas/genética , Ratos , Proteína Reelina , Nervo Isquiático/lesões , Nervo Isquiático/metabolismo , Nervo Isquiático/patologia , Neuropatia Ciática/patologia , Análise de Sequência de DNA , Traumatismos da Medula Espinal/patologia
14.
J Cell Physiol ; 235(5): 4605-4617, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-31663116

RESUMO

Spinal cord injury (SCI) is a devastating disease. Strategies that enhance the intrinsic regenerative ability are very important for the recovery of SCI to radically prevent the occurrence of sensory disorders. Epidermal growth factor (EGF) showed a limited effect on the growth of primary sensory neuron neurites due to the degradation of phosphorylated-epidermal growth factor receptor (p-EGFR) in a manner dependent on Casitas B-lineage lymphoma (CBL) (an E3 ubiquitin-protein ligase). MiR-22-3p predicted from four databases could target CBL to inhibit the expression of CBL, increase p-EGFR levels and neurites length via STAT3/GAP43 pathway rather than Erk1/2 axis. EGF, EGFR, and miR-22-3p were downregulated sharply after injury. In vivo miR-22-3p Agomir application could regulate CBL/p-EGFR/p-STAT3/GAP43/p-GAP43 axis, and restore spinal cord sensory conductive function. This study clarified the mechanism of the limited promotion effect of EGF on adult primary sensory neuron neurite and targeting miR-22-3p could be a novel strategy to treat sensory dysfunction after SCI.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Receptores ErbB/metabolismo , Proteína GAP-43/metabolismo , MicroRNAs/metabolismo , Regeneração Nervosa , Proteínas Proto-Oncogênicas c-cbl/metabolismo , Fator de Transcrição STAT3/metabolismo , Células Receptoras Sensoriais/enzimologia , Traumatismos da Medula Espinal/enzimologia , Proteínas Adaptadoras de Transdução de Sinal/genética , Animais , Células Cultivadas , Modelos Animais de Doenças , Fator de Crescimento Epidérmico/farmacologia , Receptores ErbB/agonistas , Potenciais Somatossensoriais Evocados , Feminino , MicroRNAs/genética , Regeneração Nervosa/efeitos dos fármacos , Crescimento Neuronal , Oligonucleotídeos/farmacologia , Fosforilação , Cultura Primária de Células , Proteínas Proto-Oncogênicas c-cbl/genética , Ratos Wistar , Recuperação de Função Fisiológica , Células Receptoras Sensoriais/efeitos dos fármacos , Células Receptoras Sensoriais/patologia , Transdução de Sinais , Traumatismos da Medula Espinal/tratamento farmacológico , Traumatismos da Medula Espinal/patologia , Traumatismos da Medula Espinal/fisiopatologia
15.
Biochem Biophys Res Commun ; 526(3): 793-798, 2020 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-32268957

RESUMO

Low-intensity pulsed ultrasound (LIPUS) is widely used to regulate stem cell proliferation and differentiation. However, the effect of LIPUS stimulation on neural stem cells (NSCs) is not well documented. In this study, we have identified the optimal parameters, and investigated the cellular mechanisms of LIPUS to regulate the proliferation and differentiation of NSCs in vitro. NSCs were obtained and identified by nestin immunostaining. The proliferation of NSCs were measured by using Cell Counting Kit-8 (CCK-8). The expressions of nutritional factors (NTFs) were detected with immunoassay (ELISA). NSCs differentiation were detected by immunofluorescence and immunoblotting analysis. The expression level of proteins involved in the Notch signaling pathway was also measured by immunoblotting assay. Our results showed the intensity of 69.3 mW/cm2 (1 MHz, 8 V) was applicable for LIPUS stimulation. ELISA analysis demonstrated that LIPUS treatment promoted the expression of nutritional factors of NSCs in vitro. Immunofluorescence and immunoblotting analyses suggested that the LIPUS not only reduced the astrocyte differentiation, but also stimulated the differentiation to neurons. Additionally, LIPUS stimulation significantly upregulated expression level of Notch1 and Hes1. Results from our study suggest that LIPUS triggers NSCs proliferation and differentiation by modulating the Notch signaling pathway. This study implies LIPUS as a potential and promising therapeutic platform for the optimization of stem cells and enable noninvasive neuromodulation for central nervous system diseases.


Assuntos
Células-Tronco Neurais , Receptores Notch/metabolismo , Ondas Ultrassônicas , Diferenciação Celular , Proliferação de Células , Humanos , Neurogênese , Neurônios/metabolismo , Transdução de Sinais , Fatores de Transcrição HES-1/metabolismo , Regulação para Cima
16.
Ann Rheum Dis ; 79(5): 635-645, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32156705

RESUMO

OBJECTIVES: In this study, we aim to determine the effect of metformin on osteoarthritis (OA) development and progression. METHODS: Destabilisation of the medial meniscus (DMM) surgery was performed in 10-week-old wild type and AMP-activated protein kinase (AMPK)α1 knockout (KO) mice. Metformin (4 mg/day in drinking water) was given, commencing either 2 weeks before or 2 weeks after DMM surgery. Mice were sacrificed 6 and 12 weeks after DMM surgery. OA phenotype was analysed by micro-computerised tomography (µCT), histology and pain-related behaviour tests. AMPKα1 (catalytic alpha subunit of AMPK) expression was examined by immunohistochemistry and immunofluorescence analyses. The OA phenotype was also determined by µCT and MRI in non-human primates. RESULTS: Metformin upregulated phosphorylated and total AMPK expression in articular cartilage tissue. Mild and more severe cartilage degeneration was observed at 6 and 12 weeks after DMM surgery, evidenced by markedly increased Osteoarthritis Research Society International scores, as well as reduced cartilage areas. The administration of metformin, commencing either before or after DMM surgery, caused significant reduction in cartilage degradation. Prominent synovial hyperplasia and osteophyte formation were observed at both 6 and 12 weeks after DMM surgery; these were significantly inhibited by treatment with metformin either before or after DMM surgery. The protective effects of metformin on OA development were not observed in AMPKα1 KO mice, suggesting that the chondroprotective effect of metformin is mediated by AMPK signalling. In addition, we demonstrated that treatment with metformin could also protect from OA progression in a partial medial meniscectomy animal model in non-human primates. CONCLUSIONS: The present study suggests that metformin, administered shortly after joint injury, can limit OA development and progression in injury-induced OA animal models.


Assuntos
Proteínas Quinases Ativadas por AMP/genética , Cartilagem Articular/efeitos dos fármacos , Metformina/farmacologia , Osteoartrite/tratamento farmacológico , Regulação para Cima/genética , Animais , Cartilagem Articular/patologia , Células Cultivadas , Condrócitos/efeitos dos fármacos , Condrócitos/patologia , Modelos Animais de Doenças , Progressão da Doença , Regulação da Expressão Gênica , Humanos , Hipoglicemiantes/farmacologia , Meniscos Tibiais/patologia , Meniscos Tibiais/cirurgia , Camundongos , Camundongos Knockout , Camundongos Obesos , Osteoartrite/patologia , Distribuição Aleatória , Sensibilidade e Especificidade , Transdução de Sinais/genética
17.
Gynecol Endocrinol ; 36(11): 997-1001, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32720532

RESUMO

MicroRNAs (miRNAs) represent RNA species found in serum. Many miRNAs were observed that were related to osteoporosis and osteopenia. However, expression and function analysis of miRNAs in postmenopausal osteoporosis (PMOP) remain unaddressed. We first compared the miRNA expression of blood samples in postmenopausal women with osteopenia or with osteoporosis via analysis of GSE64433. Bioinformatics analyses were conducted to get the key miRNAs and their functions and pathways. 331 miRNAs were being identified as differentially expressed miRNAs. Among these, 122 miRNA (36.86%) were up-regulated, and the remaining 209 miRNAs (63.14%) were down-regulated. 105 genes were predicted as the targets of these miRNAs. GO enrichment analysis results showed that the miRNAs mainly enriched in DNA binding, ATP binding, gene expression, regulation of the apoptotic process, chromatin binding, and protein kinase binding. KEGG enrichment analysis results demonstrated that the miRNAs mainly enriched in the TGF beta signaling pathway, wnt signaling pathway, JAK-STAT signaling pathway, and androgen receptor signaling pathway. This study identified the abundant differentially expressed miRNAs in the blood samples of postmenopausal women with osteopenia or with osteoporosis. This study may contribute to getting new diagnostic and therapeutic strategies for PMOP.


Assuntos
MicroRNAs/análise , Osteoporose Pós-Menopausa/genética , Adulto , Doenças Ósseas Metabólicas/sangue , Doenças Ósseas Metabólicas/genética , China , Biologia Computacional , Feminino , Perfilação da Expressão Gênica , Redes Reguladoras de Genes , Humanos , MicroRNAs/sangue , Análise em Microsséries , Pessoa de Meia-Idade , Osteoporose Pós-Menopausa/sangue , Transdução de Sinais/genética , Transcriptoma/genética
18.
Chin J Traumatol ; 23(4): 196-201, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32674856

RESUMO

Outbreak of COVID-19 is ongoing all over the world. Spine trauma is one of the most common types of trauma and will probably be encountered during the fight against COVID-19 and resumption of work and production. Patients with unstable spine fractures or continuous deterioration of neurological function require emergency surgery. The COVID-19 epidemic has brought tremendous challenges to the diagnosis and treatment of such patients. To coordinate the diagnosis and treatment of infectious disease prevention and spine trauma so as to formulate a rigorous diagnosis and treatment plan and to reduce the disability and mortality of the disease, multidisciplinary collaboration is needed. This expert consensus is formulated in order to (1) prevent and control the epidemic, (2) diagnose and treat patients with spine trauma reasonably, and (3) reduce the risk of cross-infection between patients and medical personnel during the treatment.


Assuntos
Betacoronavirus , Infecções por Coronavirus/epidemiologia , Pneumonia Viral/epidemiologia , Guias de Prática Clínica como Assunto , Traumatismos da Coluna Vertebral/diagnóstico , Traumatismos da Coluna Vertebral/terapia , COVID-19 , Infecções por Coronavirus/prevenção & controle , Infecção Hospitalar/prevenção & controle , Serviço Hospitalar de Emergência , Humanos , Pandemias/prevenção & controle , Equipe de Assistência ao Paciente , Pneumonia Viral/prevenção & controle , SARS-CoV-2 , Transporte de Pacientes
19.
Angew Chem Int Ed Engl ; 59(26): 10426-10430, 2020 06 22.
Artigo em Inglês | MEDLINE | ID: mdl-32190959

RESUMO

Herein, we present an electrochemophysiological microarray (ECPM) for real-time mapping and simultaneous quantification of chemical signals for multiple ions in the deep brain of a freely moving rat, in which microelectrode arrays were developed for direct determination of multiple ions using open-circuit potentiometry. Specific recognition ionophores were synthesized and optimized for determination of K+ , Ca2+ , Na+ and pH. A reference electrode was also developed to avoid interferences in the brain. The microarrays were successfully applied in real-time monitoring and quantification of ions in a live brain. The extra current-free potentiometry allowed mapping and biosensing of chemical signals, together with recording of electrical signals in the whole brain without cross-talk, for the first time. Furthermore, the ECPM provided a platform for real-time monitoring of the dynamic changes of multiple ions in the deep brain of freely moving rat during a seizure.


Assuntos
Encéfalo/metabolismo , Cálcio/análise , Monitorização Fisiológica/métodos , Potássio/análise , Sódio/análise , Animais , Anticonvulsivantes/farmacologia , Encéfalo/efeitos dos fármacos , Cálcio/metabolismo , Carbamatos/farmacologia , Diaminas/química , Técnicas Eletroquímicas/instrumentação , Técnicas Eletroquímicas/métodos , Epilepsia/metabolismo , Concentração de Íons de Hidrogênio , Ionóforos/química , Limite de Detecção , Masculino , Microeletrodos , Monitorização Fisiológica/instrumentação , Fenilenodiaminas/farmacologia , Potássio/metabolismo , Ratos Wistar , Sódio/metabolismo , Zonisamida/farmacologia
20.
J Cell Physiol ; 234(6): 8918-8927, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30341912

RESUMO

Spinal cord injury (SCI) is a highly severe disease and it can lead to the destruction of the motor and sensory function resulting in temporary or permanent disability. Long noncoding RNAs (lncRNAs) are transcripts longer than 200 nt that play a critical role in central nervous system (CNS) injury. However, the exact roles of lncRNAs and messenger RNAs (mRNAs) in the early acute phase of SCI remain to be elucidated. We examined the expression of mRNAs and lncRNAs in a rat model at 2 days after SCI and identified the differentially expressed lncRNAs (DE lncRNAs) and differentially expressed mRNAs (DE mRNAs) using microarray analysis. Subsequently, a comprehensive bioinformatics analysis was also performed to clarify the interaction between DE mRNAs. A total of 3,193 DE lncRNAs and 4,308 DE mRNAs were identified between the injured group and control group. Classification, length distribution, and chromosomal distribution of the dysregulated lncRNAs were also performed. The gene ontology analysis and Kyoto Encyclopedia of Genes and Genomes enrichment analysis were performed to identify the critical biological processes and pathways. A protein-protein interaction (PPI) network indicated that IL6, TOP2A, CDK1, POLE, CCNB1, TNF, CCNA2, CDC20, ITGAM, and MYC were the top 10 core genes. The subnetworks from the PPI network were identified to further elucidate the most significant functional modules of the DE mRNAs. These data may provide novel insights into the molecular mechanism of the early acute phase of SCI. The identification of lncRNAs and mRNAs may offer potential diagnostic and therapeutic targets for SCI.


Assuntos
RNA Longo não Codificante/metabolismo , RNA Mensageiro/metabolismo , Traumatismos da Medula Espinal/metabolismo , Animais , Biomarcadores , Feminino , Regulação da Expressão Gênica , RNA Longo não Codificante/genética , RNA Mensageiro/genética , Ratos , Ratos Sprague-Dawley , Transcriptoma
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA