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1.
Cell ; 176(6): 1407-1419.e14, 2019 03 07.
Artigo em Inglês | MEDLINE | ID: mdl-30827680

RESUMO

The function of somatic stem cells declines with age. Understanding the molecular underpinnings of this decline is key to counteract age-related disease. Here, we report a dramatic drop in the neural stem cells (NSCs) number in the aging murine brain. We find that this smaller stem cell reservoir is protected from full depletion by an increase in quiescence that makes old NSCs more resistant to regenerate the injured brain. Once activated, however, young and old NSCs show similar proliferation and differentiation capacity. Single-cell transcriptomics of NSCs indicate that aging changes NSCs minimally. In the aging brain, niche-derived inflammatory signals and the Wnt antagonist sFRP5 induce quiescence. Indeed, intervention to neutralize them increases activation of old NSCs during homeostasis and following injury. Our study identifies quiescence as a key feature of old NSCs imposed by the niche and uncovers ways to activate NSCs to repair the aging brain.


Assuntos
Encéfalo/fisiologia , Fatores Etários , Animais , Encéfalo/citologia , Diferenciação Celular/fisiologia , Divisão Celular/fisiologia , Proliferação de Células/fisiologia , Senescência Celular/fisiologia , Homeostase , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Regeneração Nervosa , Células-Tronco Neurais/citologia , Células-Tronco Neurais/fisiologia , Neurogênese , Nicho de Células-Tronco
2.
EMBO J ; 42(11): e110384, 2023 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-37083045

RESUMO

Most adult hippocampal neural stem cells (NSCs) remain quiescent, with only a minor portion undergoing active proliferation and neurogenesis. The molecular mechanisms that trigger the transition from quiescence to activation are still poorly understood. Here, we found the activity of the transcriptional co-activator Yap1 to be enriched in active NSCs. Genetic deletion of Yap1 led to a significant reduction in the relative proportion of active NSCs, supporting a physiological role of Yap1 in regulating the transition from quiescence to activation. Overexpression of wild-type Yap1 in adult NSCs did not induce NSC activation, suggesting tight upstream control mechanisms, but overexpression of a gain-of-function mutant (Yap1-5SA) elicited cell cycle entry in NSCs and hilar astrocytes. Consistent with a role of Yap1 in NSC activation, single cell RNA sequencing revealed a partial induction of an activated NSC gene expression program. Furthermore, Yap1-5SA expression also induced expression of Taz and other key components of the Yap/Taz regulon that were previously identified in glioblastoma stem cell-like cells. Consequently, dysregulated Yap1 activity led to repression of hippocampal neurogenesis, aberrant cell differentiation, and partial acquisition of a glioblastoma stem cell-like signature.


Assuntos
Glioblastoma , Células-Tronco Neurais , Adulto , Humanos , Glioblastoma/metabolismo , Diferenciação Celular/fisiologia , Hipocampo/metabolismo , Neurogênese/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Células-Tronco Neurais/metabolismo
3.
Reprod Biomed Online ; 48(4): 103727, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38402677

RESUMO

RESEARCH QUESTION: Does type 1 diabetes mellitus (T1DM) affect reproductive health of female patients? What is the potential mechanism of reproductive dysfunction in female patients caused by T1DM? DESIGN: Preliminary assessment of serum levels of female hormones in women with or without T1DM. Then histological and immunological examinations were carried out on the pancreas, ovaries and uteri at different stages in non-obese diabetic (NOD) and Institute of Cancer Research (ICR) mice, as well as assessment of their fertility. A protein array was carried out to detect the changes in serum inflammatory cytokines. Furthermore, RNA-sequencing was used to identify the key abnormal genes/pathways in ovarian and uterine tissues of female NOD mice, which were further verified at the protein level. RESULTS: Testosterone levels were significantly increased (P = 0.0036) in female mice with T1DM. Increasing age in female NOD mice was accompanied by obvious lymphocyte infiltration in the pancreatic islets. Moreover, the levels of serum inflammatory factors in NOD mice were sharply increased with increasing age. The fertility of female NOD mice declined markedly, and most were capable of conceiving only once. Furthermore, ovarian and uterine morphology and function were severely impaired in NOD female mice. Additionally, ovarian and uterine tissues revealed that the differentially expressed genes were primarily enriched in metabolism, cytokine-receptor interactions and chemokine signalling pathways. CONCLUSION: T1DM exerts a substantial impairment on female reproductive health, leading to diminished fertility, potentially associated with immune disorders and alterations in energy metabolism.


Assuntos
Diabetes Mellitus Tipo 1 , Ilhotas Pancreáticas , Humanos , Feminino , Animais , Camundongos , Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 1/metabolismo , Diabetes Mellitus Tipo 1/patologia , Camundongos Endogâmicos NOD , Pâncreas/metabolismo , Pâncreas/patologia , Ilhotas Pancreáticas/metabolismo , Ilhotas Pancreáticas/patologia , Citocinas/metabolismo , Inflamação/metabolismo
4.
Beijing Da Xue Xue Bao Yi Xue Ban ; 56(2): 273-278, 2024 Apr 18.
Artigo em Zh | MEDLINE | ID: mdl-38595244

RESUMO

OBJECTIVE: To investigate the rates of low disease activity and clinical remission in patients with systemic lupus erythematosus (SLE) in a real-world setting, and to analyze the related factors of low disease activity and clinical remission. METHODS: One thousand patients with SLE were enrolled from 11 teaching hospitals. Demographic, clinical and laboratory data, as well as treatment regimes were collec-ted by self-completed questionnaire. The rates of low disease activity and remission were calculated based on the lupus low disease activity state (LLDAS) and definitions of remission in SLE (DORIS). Charac-teristics of patients with LLDAS and DORIS were analyzed. Multivariate Logistic regression analysis was used to evaluate the related factors of LLDAS and DORIS remission. RESULTS: 20.7% of patients met the criteria of LLDAS, while 10.4% of patients achieved remission defined by DORIS. Patients who met LLDAS or DORIS remission had significantly higher proportion of patients with high income and longer disease duration, compared with non-remission group. Moreover, the rates of anemia, creatinine elevation, increased erythrocyte sedimentation rate (ESR) and hypoalbuminemia was significantly lower in the LLDAS or DORIS group than in the non-remission group. Patients who received hydroxychloroquine for more than 12 months or immunosuppressant therapy for no less than 6 months earned higher rates of LLDAS and DORIS remission. The results of Logistic regression analysis showed that increased ESR, positive anti-dsDNA antibodies, low level of complement (C3 and C4), proteinuria, low household income were negatively related with LLDAS and DORIS remission. However, hydroxychloroquine usage for longer than 12 months were positively related with LLDAS and DORIS remission. CONCLUSION: LLDAS and DORIS remission of SLE patients remain to be improved. Treatment-to-target strategy and standar-dized application of hydroxychloroquine and immunosuppressants in SLE are recommended.


Assuntos
Hidroxicloroquina , Lúpus Eritematoso Sistêmico , Humanos , Hidroxicloroquina/uso terapêutico , Lúpus Eritematoso Sistêmico/tratamento farmacológico , Imunossupressores/uso terapêutico , Índice de Gravidade de Doença
5.
BMC Genomics ; 24(1): 658, 2023 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-37919673

RESUMO

BACKGROUND: Wolfberry is rich in carotenoids, flavonoids, vitamins, alkaloids, betaines and other bioactive ingredients. For over 2,000 years, wolfberry has been used in China as a medicinal and edible plant resource. Nevertheless, the content of bioactive ingredients varies by cultivars, resulting in uneven quality across wolfberry cultivars and species. To date, research has revealed little about the underlying molecular mechanism of the metabolism of flavonoids, carotenoids, and other bioactive ingredients in wolfberry. RESULTS: In this context, the transcriptomes of the Lycium barbarum L. cultivar 'Ningqi No. 1' and Lycium chinense Miller were compared during the fruit maturity stage using the Illumina NovaSeq 6000 sequencing platform, and subsequently, the changes of the gene expression profiles in two types of wolfberries were analysed. In total, 256,228,924 clean reads were obtained, and 8817 differentially expressed genes (DEGs) were identified, then assembled by Basic Local Alignment Search Tool (BLAST) similarity searches and annotated using Gene Ontology (GO), Clusters of Orthologous Groups of proteins (KOG), and the Kyoto Encyclopedia of Genes and Genomes (KEGG). By combining these transcriptome data with data from the PubMed database, 36 DEGs related to the metabolism of bioactive ingredients and implicated in the metabolic pathway of carotenoids, flavonoids, terpenoids, alkaloids, vitamins, etc., were identified. In addition, among the 9 differentially expressed transcription factors, LbAPL, LbPHL11 and LbKAN4 have raised concerns. The protein physicochemical properties, structure prediction and phylogenetic analysis indicated that LbAPL and LbPHL11 may be good candidate genes involved in regulating the flavonoid metabolism pathway in wolfberry. CONCLUSIONS: This study provides preliminary evidence for the differences in bioactive ingredient content at the transcription level among different wolfberry species, as well as a research and theoretical basis for the screening, cloning and functional analysis of key genes involved in the metabolism of bioactive ingredients in wolfberry.


Assuntos
Alcaloides , Lycium , Lycium/genética , Filogenia , Flavonoides , Redes e Vias Metabólicas/genética , Carotenoides/metabolismo , Vitaminas/metabolismo
6.
Nano Lett ; 22(4): 1467-1474, 2022 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-35133160

RESUMO

Fundamental understanding of ion migration inside perovskites is of vital importance for commercial advancements of photovoltaics. However, the mechanism for external ions incorporation and its effect on ion migration remains elusive. Herein, taking K+ and Cs+ co-incorporated mixed halide perovskites as a model, the impact of external ions on ion migration behavior has been interpreted via multiple dimensional characterization aspects. The space-effect on phase segregation inhibition has been revealed by the photoluminescence evolution and in situ dynamic cathodoluminescence behaviors. The plane-effect on current suppression along grain boundary has been evidenced via visualized surface current mapping, local current hysteresis, and time-resolved current decay. And the point-effect on activation energy incremental for individual ions has been also probed by cryogenic electronic quantification. All these results sufficiently demonstrate the passivated ion migration results in the eventually improved phase stability of perovskite, of which the origin lies in various ion migration energy barriers.

7.
Clin Exp Rheumatol ; 40(3): 544-550, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33938794

RESUMO

OBJECTIVES: The objective of this study is to describe the clinical features of patients with axial spondyloarthritis (axial SpA) in the ChinaSpA registry. METHODS: Patients with clinical diagnosis of ankylosing spondylitis (AS) or axial SpA were enrolled into the registry. Patients with a complete set of pelvis radiograph, pelvis MRI and HLA-B27 (Complete Set group, CS group) were further categorised based on classification criteria into AS, radiographic axial SpA (r-axSpA) and non-radiographic axial SpA (nr-axSpA). Early axial SpA was defined as symptom duration of less than three years. Descriptive statistics were used to describe clinical characteristics of enrolled patients. ANOVA analyses were used to compare patients in different groups. RESULTS: A total of 5270 patients were enrolled in the study, and 3223 patients had complete sets of pelvis radiographs, MRIs and HLA-B27 status. Among them, more than 80% patients met both the ASAS criteria for r-axSpA and the modified New York criteria for AS. Among those with early axial SpA, 92% of patients had sacroiliitis on pelvis radiograph, 3.8% had sacroiliitis only on pelvis MRI, and 3.8% were in the clinical arm without any sacroiliitis on imaging studies. Patients in nr-axSpA clinical arm had less diagnosis delay, lower inflammatory markers and ASDAS, compared topatients in the r-axSpA, nr-axSpA MRI arm. CONCLUSIONS: In the ChinaSpA registry, patients in nr-axSpA clinical arm had the shortest diagnostic delay, lower inflammatory markers and ASDAS, but no difference in extra-articular manifestation, compared to patients in the r-axSpA and nr-axSpA MRI arm.


Assuntos
Espondiloartrite Axial , Espondilartrite , Espondilite Anquilosante , Diagnóstico Tardio , Antígeno HLA-B27/genética , Humanos , Sistema de Registros , Espondilartrite/diagnóstico por imagem , Espondilartrite/epidemiologia
8.
Appl Opt ; 61(13): 3566-3578, 2022 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-36256394

RESUMO

For large ground-based telescopes, static and dynamic disturbances would greatly degrade the optical performance. This is especially true for wide field survey telescopes with prime focus optics. The estimation of disturbance effects on large telescopes is becoming increasingly important during the design phase. Therefore, a wide field survey telescope with 2.5 m aperture and 3.5 deg field of view is studied in this research. This telescope is under construction now, and its first light is expected at the beginning of 2023. The estimation method for the optical performance under static and dynamic disturbances in the temporal domain and the active compensation method to improve the optical alignment, are investigated, which is a supplement for the simulation in the frequency domain. First, based on the mechanical model, the optical misalignment is established, where the deviation of the primary mirror is obtained from the length gauges and the deviation of the corrector is computed using the fitting method. Second, a method for compensating the static and dynamic disturbances is proposed, improving the optical performance. This method uses the disturbed primary mirror as the reference, and the corrector is actively controlled to align with it. Finally, a series of experimental tests and numerical simulations is conducted. The results show that the mechanical modeling error is within 10% and the maximum optical misalignment is reduced from 12''/0.27 to 0.2''/0.006mm for static disturbance and from 1.3''/0.03 to 0.4''/0.01mm for dynamic disturbance. Through active compensation, the telescope optical property is greatly improved. The modeling method and the simulation process mentioned in this research can also be used in the other relevant fields.

9.
Hum Mol Genet ; 28(6): 961-971, 2019 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-30476097

RESUMO

Spastic paraplegia gene 11(SPG11)-linked hereditary spastic paraplegia is a complex monogenic neurodegenerative disease that in addition to spastic paraplegia is characterized by childhood onset cognitive impairment, thin corpus callosum and enlarged ventricles. We have previously shown impaired proliferation of SPG11 neural progenitor cells (NPCs). For the delineation of potential defect in SPG11 brain development we employ 2D culture systems and 3D human brain organoids derived from SPG11 patients' iPSC and controls. We reveal that an increased rate of asymmetric divisions of NPCs leads to proliferation defect, causing premature neurogenesis. Correspondingly, SPG11 organoids appeared smaller than controls and had larger ventricles as well as thinner germinal wall. Premature neurogenesis and organoid size were rescued by GSK3 inhibititors including the Food and Drug Administration-approved tideglusib. These findings shed light on the neurodevelopmental mechanisms underlying disease pathology.


Assuntos
Córtex Cerebral/embriologia , Córtex Cerebral/metabolismo , Neurogênese/genética , Proteínas/genética , Alelos , Biomarcadores , Córtex Cerebral/fisiopatologia , Transtornos Cognitivos/genética , Transtornos Cognitivos/fisiopatologia , Suscetibilidade a Doenças , Imunofluorescência , Genótipo , Quinase 3 da Glicogênio Sintase/metabolismo , Humanos , Mutação , Organoides , Fenótipo , beta Catenina
10.
Reprod Biol Endocrinol ; 19(1): 187, 2021 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-34906165

RESUMO

BACKGROUND: Recurrent implantation failure (RIF) is a major limitation of assisted reproductive technology, which is associated with impaired endometrial receptivity. Although N6-methyladenosine (m6A) has been demonstrated to be involved in various biological processes, its potential role in the endometrium of women with RIF has been poorly studied. METHODS: Global m6A levels and major m6A methyltransferases/demethylases mRNA levels in mid-secretory endometrium from normal and RIF women were examined by colorimetric m6A quantification strategy and quantitative real-time PCR, respectively. The effects of METTL3-mediated m6A modification on embryo attachment were evaluated by an vitro model of a confluent monolayer of Ishikawa cells co-cultured with BeWo spheroids, and the expression levels of homeo box A10 (HOXA10, a well-characterized marker of endometrial receptivity) and its downstream targets were evaluated by quantitative real-time PCR and Western blotting in METTL3-overexpressing Ishikawa cells. The molecular mechanism for METTL3 regulating HOXA10 expression was determined by methylated RNA immunoprecipitation assay and transcription inhibition assay. RESULTS: Global m6A methylation and METTL3 expression were significantly increased in the endometrial tissues from women with RIF compared with the controls. Overexpression of METTL3 in Ishikawa cells significantly decreased the ration of BeWo spheroid attachment, and inhibited HOXA10 expression with downstream decreased ß3-integrin and increased empty spiracles homeobox 2 expression. METTL3 catalyzed the m6A methylation of HOXA10 mRNA and contributed to its decay with shortened half-life. Enforced expression of HOXA10 in Ishikawa cells effectively rescued the impairment of METTL3 on the embryo attachment in vitro. CONCLUSION: Increased METTL3-mediated m6A modification represents an adverse impact on embryo implantation by inhibiting HOXA10 expression, contributing to the pathogenesis of RIF.


Assuntos
Implantação do Embrião/genética , Endométrio/metabolismo , Proteínas Homeobox A10/metabolismo , Infertilidade Feminina/metabolismo , Metiltransferases/metabolismo , Adulto , Linhagem Celular Tumoral , Metilação de DNA , Feminino , Proteínas Homeobox A10/genética , Humanos , Infertilidade Feminina/genética , Metiltransferases/genética
11.
Nutr Cancer ; 73(2): 252-261, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32285694

RESUMO

In this systematic review and meta-analysis, 25 clinical trials were systematically reviewed, and meta-analysis was performed with the results of 16 trials. It was found that the risk of surgical site infection was significantly lower in patients who received perioperative immunonutrition than those given standard nutrition. Furthermore, hospital stay was significantly shorter in patients receiving immunonutrition or early enteral nutrition after surgical resection of gastric cancer. Perioperative immunonutrition also significantly reduced white blood cell counts and the level of C-reactive protein in the patients. However, neither CD4+ T cells nor inflammatory cytokines were significantly affected even though immunonutrition was in favor. These findings suggested that patients with gastrointestinal cancer may benefit from perioperative immunonutrition support by reducing surgery-associated complications and shortening hospital stay. The effects and the underlying mechanism of immunonutrition on immunological modulation and inflammatory regulation, however, remain to be further defined.


Assuntos
Neoplasias Gastrointestinais , Neoplasias Gástricas , Nutrição Enteral , Neoplasias Gastrointestinais/cirurgia , Humanos , Tempo de Internação , Complicações Pós-Operatórias/prevenção & controle , Neoplasias Gástricas/cirurgia
12.
Angew Chem Int Ed Engl ; 59(28): 11573-11582, 2020 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-32259338

RESUMO

The matching of charge transport layer and photoactive layer is critical in solar energy conversion devices, especially for planar perovskite solar cells based on the SnO2 electron-transfer layer (ETL) owing to its unmatched photogenerated electron and hole extraction rates. Graphdiyne (GDY) with multi-roles has been incorporated to maximize the matching between SnO2 and perovskite regarding electron extraction rate optimization and interface engineering towards both perovskite crystallization process and subsequent photovoltaic service duration. The GDY doped SnO2 layer has fourfold improved electron mobility due to freshly formed C-O σ bond and more facilitated band alignment. The enhanced hydrophobicity inhibits heterogeneous perovskite nucleation, contributing to a high-quality film with diminished grain boundaries and lower defect density. Also, the interfacial passivation of Pb-I anti-site defects has been demonstrated via GDY introduction.

13.
Cereb Cortex ; 28(12): 4454-4471, 2018 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-30307491

RESUMO

Neural stem cells (NSCs) in the adult mouse hippocampus occur in a specific neurogenic niche, where a multitude of extracellular signaling molecules converges to regulate NSC proliferation as well as fate and functional integration. However, the underlying mechanisms how NSCs react to extrinsic signals and convert them to intracellular responses still remains elusive. NSCs contain a functional endocannabinoid system, including the cannabinoid type-1 receptor (CB1). To decipher whether CB1 regulates adult neurogenesis directly or indirectly in vivo, we performed NSC-specific conditional inactivation of CB1 by using triple-transgenic mice. Here, we show that lack of CB1 in NSCs is sufficient to decrease proliferation of the stem cell pool, which consequently leads to a reduction in the number of newborn neurons. Furthermore, neuronal differentiation was compromised at the level of dendritic maturation pointing towards a postsynaptic role of CB1 in vivo. Deteriorated neurogenesis in NSC-specific CB1 knock-outs additionally resulted in reduced long-term potentiation in the hippocampal formation. The observed cellular and physiological alterations led to decreased short-term spatial memory and increased depression-like behavior. These results demonstrate that CB1 expressed in NSCs and their progeny controls neurogenesis in adult mice to regulate the NSC stem cell pool, dendritic morphology, activity-dependent plasticity, and behavior.


Assuntos
Hipocampo/fisiologia , Potenciação de Longa Duração , Células-Tronco Neurais/fisiologia , Neurogênese , Receptor CB1 de Canabinoide/fisiologia , Animais , Comportamento Animal , Hipocampo/citologia , Masculino , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Células-Tronco Neurais/citologia , Receptor CB1 de Canabinoide/genética , Memória Espacial/fisiologia
14.
BMC Plant Biol ; 18(1): 73, 2018 04 30.
Artigo em Inglês | MEDLINE | ID: mdl-29712565

RESUMO

Following publication of the original article [1], a reader spotted that the article appears to have some misplaced/duplicated figures. In particular, Fig. 5a and Fig. 6a appear to be identical, and do not match what is written in the text. The authors apologized for this oversight and supplied the original pictures, which are reproduced below.

15.
BMC Plant Biol ; 18(1): 78, 2018 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-29728056

RESUMO

BACKGROUND: Alfalfa (Medicago sativa L.) is one of the most important forage resources in the world due to its high nutritive value. However, its nutritional quality decreases during the transition from budding to flowering. Previous research revealed a decreased crude protein content and increased fibre content in alfalfa forage harvested at later maturity stages, leading to a reduction in nutritional quality. However, the reasons for this phenomenon have not been explained at the molecular level. RESULTS: In this study, leaves from the WL319HQ alfalfa cultivar were harvested at two developmental stages (budding and mid-flowering). The leaves were used to test the variable expression of proteins and metabolites during these stages. TMT-based quantitative proteomics and LC-MS/MS-based untargeted metabolomics methods were employed in this study. A total of 415 proteins and 49 metabolites showed at least a 1.2-fold difference in abundance during these stages. Most of the differentially expressed proteins and metabolites were involved in metabolic processes, including carbohydrate metabolism, starch and sucrose metabolism, phenylpropanoid biosynthesis, and biosynthesis of amino acids. Alfalfa leaves in mid-flowering contain less crude protein due to the decrease in L-glutamic acid content. Carbohydrate metabolism provides the raw material for the synthesis of hemicellulose, resulting in an increase in the hemicellulose content of the alfalfa leaves, leading to an increase in the NDF content. In addition, the increase in L-phenylalanine content could have provided the conditions necessary for lignin synthesis. These are the main factors leading to reductions in alfalfa relative feed value (RFV) and quality. CONCLUSIONS: This study used joint proteomic and metabolomic analyses to elucidate the relationship between the reduction in the nutritional value of alfalfa and complex biological processes. This provides a theoretical basis for producing high-quality alfalfa hay and sets the stage for further research.


Assuntos
Medicago sativa/metabolismo , Nutrientes/metabolismo , Metabolismo dos Carboidratos , Cromatografia Gasosa-Espectrometria de Massas , Espectrometria de Massas , Medicago sativa/crescimento & desenvolvimento , Metabolômica , Valor Nutritivo , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Proteínas de Plantas/metabolismo , Polissacarídeos/metabolismo , Proteômica
16.
Chembiochem ; 19(12): 1271-1279, 2018 06 18.
Artigo em Inglês | MEDLINE | ID: mdl-29633466

RESUMO

Neuro-regeneration after trauma requires growth and reconnection of neurons to reestablish information flow in particular directions across the damaged tissue. To support this process, biomaterials for nerve tissue regeneration need to provide spatial information to adhesion receptors on the cell membrane and to provide directionality to growing neurites. Here, photoactivatable adhesive peptides based on the CASIKVAVSADR laminin peptidomimetic are presented and applied to spatiotemporal control of neuronal growth to biomaterials in vitro. The introduction of a photoremovable group [6-nitroveratryl (NVOC), 3-(4,5-dimethoxy-2-nitrophenyl)butan-2-yl (DMNPB), or 2,2'-((3'-(1-hydroxypropan-2-yl)-4'-nitro-[1,1'-biphenyl]-4-yl)azanediyl)bis(ethan-1-ol) (HANBP)] at the amino terminal group of the K residue temporally inhibited the activity of the peptide. The bioactivity was regained through controlled light exposure. When used in neuronal culture substrates, the peptides allowed light-based control of the attachment and differentiation of neuronal cells. Site-selective irradiation activated adhesion and differentiation cues and guided seeded neurons to grow in predefined patterns. This is the first demonstration of ligand-based light-controlled interaction between neuronal cells and biomaterials.


Assuntos
Materiais Biocompatíveis/farmacologia , Neurogênese/efeitos dos fármacos , Neurogênese/efeitos da radiação , Neurônios/efeitos dos fármacos , Neurônios/efeitos da radiação , Peptídeos/farmacologia , Sequência de Aminoácidos , Animais , Materiais Biocompatíveis/química , Adesão Celular/efeitos dos fármacos , Adesão Celular/efeitos da radiação , Células Cultivadas , Laminina/química , Laminina/farmacologia , Ligantes , Camundongos Endogâmicos C57BL , Neurônios/citologia , Peptídeos/química , Fotólise
17.
Biomacromolecules ; 18(3): 906-913, 2017 03 13.
Artigo em Inglês | MEDLINE | ID: mdl-28147484

RESUMO

Biomaterials for cell culture allowing simple and quantitative presentation of instructive cues enable rationalization of the interplay between cells and their surrounding microenvironment. Poly(acrylamide) (PAAm) hydrogels are popular 2D-model substrates for this purpose. However, quantitative and reproducible biofunctionalization of PAAm hydrogels with multiple ligands in a trustable, controlled, and independent fashion is not trivial. Here, we describe a method for bifunctional modification of PAAm hydrogels with thiol- and amine- containing biomolecules with controlled densities in an independent, orthogonal manner. We developed copolymer networks of AAm with 9% acrylic acid and 2% N-(4-(5-(methylsulfonyl)-1,3,4-oxadiazol-2-yl)phenyl)acrylamide. The covalent binding of thiol- and amine-containing chromophores at tunable concentrations was demonstrated and quantified by UV spectroscopy. The morphology, mechanical properties, and homogeneity of the copolymerized hydrogels were characterized by scanning electron microscopy, dynamic mechanical analysis, and confocal microscopy studies. Our copolymer hydrogels were bifunctionalized with polylysine and a laminin-mimetic peptide using the specific chemistries. We analyzed the effect of binding protocol of the two components in the maturation of cultured postmitotic cortical neurons. Our substrates supported neuronal attachment, proliferation, and neuronal differentiation. We found that neurons cultured on our hydrogels bifunctionalized with ligand-specific chemistries in a sequential fashion exhibited higher maturation at comparable culture times than using a simultaneous bifunctionalization strategy, displaying a higher number of neurites, branches, and dendritic filopodia. These results demonstrate the relevance of quantitative and optimized coupling chemistries for the performance of simple biomaterials and with sensitive cell types.


Assuntos
Resinas Acrílicas/química , Materiais Biocompatíveis/química , Hidrogéis/química , Animais , Células Cultivadas , Laminina/química , Camundongos , Camundongos Endogâmicos C57BL , Polilisina/química , Polímeros/química
18.
BMC Plant Biol ; 16: 99, 2016 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-27101806

RESUMO

BACKGROUND: The different actions of abscisic acid (ABA) in the aboveground and belowground parts of plants suggest the existence of a distinct perception mechanism between these organs. Although characterization of the soluble ABA receptors PYR1/PYL/RCAR as well as core signaling components has greatly advanced our understanding of ABA perception, signal transduction, and responses, the environment-dependent organ-specific sensitivity of plants to ABA is less well understood. RESULTS: By performing real-time quantitative PCR assays, we comprehensively compared transcriptional differences of core ABA signaling components in response to ABA or osmotic/dehydration stress between maize (Zea mays L.) roots and leaves. Our results demonstrated up-regulation of the transcript levels of ZmPYLs homologous to dimeric-type Arabidopsis ABA receptors by ABA in maize primary roots, whereas those of ZmPYLs homologous to monomeric-type Arabidopsis ABA receptors were down-regulated. However, this trend was reversed in the leaves of plants treated with ABA via the root medium. Although the mRNA levels of ZmPYL1-3 increased significantly in roots subjected to polyethylene glycol (PEG)-induced osmotic stress, ZmPYL4-11 transcripts were either maintained at a stable level or increased only slightly. In detached leaves subjected to dehydration, the transcripts of ZmPYL1-3 together with ZmPYL5, ZmPYL6, ZmPYL10 and ZmPYL11 were decreased, whereas those of ZmPYL4, ZmPYL7 and ZmPYL8 were significantly increased. Our results also showed that all of the evaluated transcripts of PP2Cs and SnRK2 were quickly up-regulated in roots by ABA or osmotic stress; conversely they were either up-regulated or maintained at a constant level in leaves, depending on the isoforms within each family. CONCLUSIONS: There is a distinct profile of PYR/PYL/RCAR ABA receptor gene expression between maize roots and leaves, suggesting that monomeric-type ABA receptors are mainly involved in the transmission of ABA signals in roots but that dimeric-type ABA receptors primarily carry out this function in leaves. Given that ZmPYL1 and ZmPYL4 exhibit similar transcript abundance under normal conditions, our findings may represent a novel mechanism for species-specific regulation of PYR/PYL/RCAR ABA receptor gene expression. A difference in the preference for core signaling components in the presence of exogenous ABA versus stress-induced endogenous ABA was observed in both leaves and roots. It appears that core ABA signaling components perform their osmotic/dehydration stress response functions in a stress intensity-, duration-, species-, organ-, and isoform-specific manner, leading to plasticity in response to adverse conditions and, thus, acclimation to life on land. These results deepen our understanding of the diverse biological effects of ABA between plant leaves and roots in response to abiotic stress at the stimulus-perception level.


Assuntos
Ácido Abscísico/farmacologia , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Folhas de Planta/genética , Proteínas de Plantas/genética , Raízes de Plantas/genética , Receptores de Superfície Celular/genética , Plântula/genética , Zea mays/genética , Ácido Abscísico/metabolismo , Arabidopsis/genética , Desidratação , Relação Dose-Resposta a Droga , Perfilação da Expressão Gênica/métodos , Filogenia , Reguladores de Crescimento de Plantas/metabolismo , Reguladores de Crescimento de Plantas/farmacologia , Proteínas de Plantas/classificação , Polietilenoglicóis/farmacologia , Receptores de Superfície Celular/classificação , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Tempo , Regulação para Cima/efeitos dos fármacos
19.
J Neurochem ; 135(2): 261-73, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26178610

RESUMO

Stabilized microtubules are required for neuronal morphogenesis and migration. However, the underlying mechanism is not fully understood. In this study, we demonstrate that myosin X (Myo10), which is composed of full-length myosin X (fMyo10) and headless myosin X (hMyo10), is important for axon development. fMyo10 is involved in axon elongation, whereas hMyo10 is critical for Tau-1 positive axon formation through stabilizing microtubules. Furthermore, in vivo studies reveal that hMyo10-mediated microtubule stability has a profound effect on both neuronal migration and dendritic arborization in the mammalian cerebral cortex. Taken together, our findings suggest that hMyo10 is involved in neuronal development both in vitro and in vivo by regulating microtubule stability.


Assuntos
Microtúbulos/fisiologia , Miosinas/fisiologia , Neurônios/fisiologia , Animais , Axônios/fisiologia , Movimento Celular/fisiologia , Células Cultivadas , Dendritos/fisiologia , Eletroporação , Feminino , Camundongos , Neurogênese/genética , Gravidez , Transfecção
20.
Reprod Sci ; 31(6): 1719-1731, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38396297

RESUMO

Diabetes is known to negatively affect male reproduction. Recent clinical results have confirmed that mesenchymal stem cell (MSC)-based therapies are safe and effective for the treatment of diabetes. However, the effect and potential mechanism through which MSC transplantation improves diabetes-derived male reproductive dysfunction are still unknown. In the present study, we first established a male T1D mouse model through intraperitoneal injection of streptozotocin for five consecutive days. Subsequently, we evaluated the blood glucose levels, fertility, and histology and immunology of the pancreas, testes, and penis of T1D mice with or without transplantation of menstrual blood-derived endometrial stem cells (MenSCs) or umbilical cord mesenchymal stem cells (UCMSCs). Glucose was added to the medium in which the Leydig cells were cultured to imitate high glucose-injured cell viability. Subsequently, we evaluated the cellular viability, ROS levels, and mitochondrial membrane potential of Leydig cells treated with or without MenSC-conditioned medium (MenSC-CM) using a CCK8 assay, immunofluorescence, and flow cytometry. The targeted proteins are involved in the potential mechanism underlying MenSC-derived improvements, which was further validated via Western blotting. Collectively, our results indicated that MenSC transplantation significantly ameliorated reproductive dysfunction in male T1D mice by enhancing cellular antioxidative capacity and promoting angiogenesis. This study provides solid evidence and support for the application of MSCs to improve diabetes-induced male reproductive dysfunction.


Assuntos
Diabetes Mellitus Experimental , Endométrio , Animais , Masculino , Camundongos , Diabetes Mellitus Experimental/terapia , Feminino , Endométrio/metabolismo , Endométrio/patologia , Células Intersticiais do Testículo/metabolismo , Antioxidantes/farmacologia , Infertilidade Masculina/terapia , Diabetes Mellitus Tipo 1/metabolismo , Diabetes Mellitus Tipo 1/terapia , Transplante de Células-Tronco Mesenquimais/métodos , Espécies Reativas de Oxigênio/metabolismo , Camundongos Endogâmicos C57BL
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