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1.
Nature ; 611(7934): 180-187, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36289327

RESUMO

Bestrophin-2 (BEST2) is a member of the bestrophin family of calcium-activated anion channels that has a critical role in ocular physiology1-4. Here we uncover a directional permeability of BEST2 to glutamate that heavily favours glutamate exit, identify glutamine synthetase (GS) as a binding partner of BEST2 in the ciliary body of the eye, and solve the structure of the BEST2-GS complex. BEST2 reduces cytosolic GS activity by tethering GS to the cell membrane. GS extends the ion conducting pathway of BEST2 through its central cavity and inhibits BEST2 channel function in the absence of intracellular glutamate, but sensitizes BEST2 to intracellular glutamate, which promotes the opening of BEST2 and thus relieves the inhibitory effect of GS. We demonstrate the physiological role of BEST2 in conducting chloride and glutamate and the influence of GS in non-pigmented ciliary epithelial cells. Together, our results reveal a novel mechanism of glutamate release through BEST2-GS.


Assuntos
Bestrofinas , Glutamato-Amônia Ligase , Ácido Glutâmico , Glutamina , Bestrofinas/metabolismo , Células Epiteliais/metabolismo , Glutamato-Amônia Ligase/metabolismo , Ácido Glutâmico/metabolismo , Glutamina/metabolismo , Corpo Ciliar/metabolismo , Membrana Celular/metabolismo , Cloretos/metabolismo
2.
Proc Natl Acad Sci U S A ; 120(12): e2218825120, 2023 03 21.
Artigo em Inglês | MEDLINE | ID: mdl-36917666

RESUMO

Interferons (IFNs) and the products of interferon-stimulated genes (ISGs) play crucial roles in host defense against virus infections. Although many ISGs have been characterized with respect to their antiviral activity, their target specificities and mechanisms of action remain largely unknown. Kaposi's sarcoma-associated herpesvirus (KSHV) is a gammaherpesvirus that is linked to several human malignancies. Here, we used the genetically and biologically related virus, murine gammaherpesvirus 68 (MHV-68) and screened for ISGs with anti-gammaherpesvirus activities. We found that overexpression of RNF213 dramatically inhibited MHV-68 infection, whereas knockdown of endogenous RNF213 significantly promoted MHV-68 proliferation. Importantly, RNF213 also inhibited KSHV de novo infection, and depletion of RNF213 in the latently KSHV-infected iSLK-219 cell line significantly enhanced lytic reactivation. Mechanistically, we demonstrated that RNF213 targeted the Replication and Transcription Activator (RTA) of both KSHV and MHV-68, and promoted the degradation of RTA protein through the proteasome-dependent pathway. RNF213 directly interacted with RTA and functioned as an E3 ligase to ubiquitinate RTA via K48 linkage. Taken together, we conclude that RNF213 serves as an E3 ligase and inhibits the de novo infection and lytic reactivation of gammaherpesviruses by degrading RTA through the ubiquitin-proteasome pathway.


Assuntos
Gammaherpesvirinae , Infecções por Herpesviridae , Herpesvirus Humano 8 , Proteínas Imediatamente Precoces , Humanos , Adenosina Trifosfatases/metabolismo , Gammaherpesvirinae/genética , Regulação Viral da Expressão Gênica , Infecções por Herpesviridae/genética , Herpesvirus Humano 8/metabolismo , Proteínas Imediatamente Precoces/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , Transativadores/metabolismo , Fatores de Transcrição/metabolismo , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Latência Viral/genética , Replicação Viral
3.
Mol Pharm ; 2024 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-38920116

RESUMO

The continuous evolution of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has evaded the efficacy of previously developed antibodies and vaccines, thus remaining a significant global public health threat. Therefore, it is imperative to develop additional antibodies that are capable of neutralizing emerging variants. Nanobodies, as the smallest functional single-domain antibodies, exhibit enhanced stability and penetration ability, enabling them to recognize numerous concealed epitopes that are inaccessible to conventional antibodies. Herein, we constructed an immune library based on the immunization of alpaca with the S1 subunit of the SARS-CoV-2 spike protein, from which two nanobodies, Nb1 and Nb2, were selected using phage display technology for further characterization. Both nanobodies, with the binding residues residing within the receptor-binding domain (RBD) region of the spike, exhibited high affinity toward the S1 subunit. Moreover, they displayed cross-neutralizing activity against both wild-type SARS-CoV-2 and 10 ο variants, including BA.1, BA.2, BA.3, BA.5, BA.2.75, BF.7, BQ.1, EG.5.1, XBB.1.5, and JN.1. Molecular modeling and dynamics simulations predicted that both nanobodies interacted with the viral RBD through their complementarity determining region 1 (CDR1) and CDR2. These two nanobodies are novel tools for the development of therapeutic and diagnostic countermeasures targeting SARS-CoV-2 variants and potentially emerging coronaviruses.

4.
Protein Expr Purif ; 203: 106199, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36372201

RESUMO

Chitosanases hydrolyze chitosan into chitooligosaccharides (COSs) with various biological activities, which are widely employed in many areas including plant disease management. In this study, the novel chitosanase AqCsn1 belonging to the glycoside hydrolase family 46 (GH46) was cloned from Aquabacterium sp. A7-Y and heterologously expressed in Escherichia coli BL21 (DE3). AqCsn1 displayed the highest hydrolytic activity towards chitosan with 95% degree of deacetylation at 40 °C and pH 5.0, with a specific activity of 13.18 U/mg. Product analysis showed that AqCsn1 hydrolyzed chitosan into (GlcN)2 and (GlcN)3 as the main products, demonstrating an endo-type cleavage pattern. Evaluation of antagonistic activity showed that the hydrolysis products of AqCsn1 suppress the mycelial growth of Magnaporthe oryzae and Phytophthora sojae in a concentration-dependent manner, and the inhibition rate of P. sojae reached 39.82% at a concentration of 8 g/L. Our study demonstrates that AqCsn1 and hydrolysis products with a low degree of polymerization might have potential applications in the biological control of agricultural diseases.


Assuntos
Quitosana , Quitosana/farmacologia , Polimerização , Quitina , Oligossacarídeos/farmacologia , Glicosídeo Hidrolases/genética , Glicosídeo Hidrolases/química , Hidrólise , Escherichia coli/genética
5.
Clin Lab ; 69(8)2023 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-37560870

RESUMO

BACKGROUND: This study aimed to investigate the value of miR-671-5p in multiple myeloma (MM) in diagnostics and prognosis and developed a potential biomarker to improve the prognosis of MM. METHODS: Plasma cells were isolated from bone marrow samples of 80 MM patients, in which miR-671-5p levels were determined. The correlation between miR-671-5p expression with serum creatinine, ß-2-microglobulin, lactate dehydrogenase, bone lesions, International Staging System staging, chromosomal abnormalities, and albumin was analyzed. The association between miR-671-5p expression with progression-free survival and overall survival in MM patients was determined. RESULTS: miR-671-5p expression was reduced and predicted an increased risk of MM. miR-671-5p expression was negatively correlated with serum creatinine, ß-2-microglobulin, lactate dehydrogenase, bone lesions, International Staging System staging, and chromosomal abnormalities, and positively correlated with albumin. miR-671-5p expression was augmented in complete response patients and overall response rate patients, and differentiated CR and ORR patients from Non-CR and Non-ORR patients. Furthermore, miR-671-5p low expression was associated with unfavorable progression-free survival and overall survival in MM patients. CONCLUSIONS: In a word, miR-671-5p is associated with worsening clinical properties, increased ISS staging, unfavorable chromosomal abnormalities, and poor prognosis in MM patients.


Assuntos
MicroRNAs , Mieloma Múltiplo , Humanos , MicroRNAs/genética , Mieloma Múltiplo/diagnóstico , Mieloma Múltiplo/genética , Creatinina , Prognóstico , Albuminas , Aberrações Cromossômicas , Lactato Desidrogenases
6.
Ann Diagn Pathol ; 66: 152165, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37348414

RESUMO

PURPOSE: Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous group of non-Hodgkin lymphoma, characterized by a variety of clinicopathological, histomorphological, immunophenotypic, and molecular genetic features. The subtype of DLBCL known as double-expressor lymphoma (DEL) is associated with an adverse prognosis when treated with R-CHOP. Our study aimed to investigate the clinicopathologic features of DEL and the prognostic roles of Myc rearrangement and C-Myc expression in DEL patients. PATIENTS AND METHODS: We conducted a retrospective study of 145 patients who were identified through fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC) testing. RESULTS: We found that DEL patients were more likely to have a non-germinal center B-cell (GCB) subtype, stage III/IV disease, and a high International Prognostic Index (IPI) score. Our survival analysis indicated that Myc rearrangement and C-Myc expression were associated with poor prognosis. Although DEL patients with Myc rearrangement exhibited trends towards worse survival compared with patients without Myc rearrangement, the differences were not statistically significant (P = 0.4008). The median overall survival (OS) of DEL patients with ≥70 % C-Myc expression (DEL-C-Mychigh) was 5 months. In the DEL-C-Mychigh group, the non-GCB subtype showed nonsignificant trends towards poorer survival compared with the GCB subtype (P = 0.1042). CONCLUSION: In conclusion, our study shows that a cut-off of ≥70 % for C-Myc expression in DEL patients can improve risk stratification, and suggests that more intensive treatment regimens may be necessary to improve survival in this high-risk population.


Assuntos
Linfoma Difuso de Grandes Células B , Proteínas Proto-Oncogênicas c-myc , Humanos , Estudos Retrospectivos , Hibridização in Situ Fluorescente , Proteínas Proto-Oncogênicas c-myc/genética , Proteínas Proto-Oncogênicas c-myc/metabolismo , Prognóstico , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Linfoma Difuso de Grandes Células B/diagnóstico , Linfoma Difuso de Grandes Células B/genética , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico
7.
Opt Express ; 30(13): 22885-22900, 2022 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-36224979

RESUMO

Functional tunability, environmental adaptability, and easy fabrication are highly desired properties in metasurfaces. Here we provide a tunable bilayer metasurface composed of two stacked identical dielectric magnetic mirrors. The magnetic mirrors are excited by the interaction between the interference of multipoles of each cylinder and the lattice resonance of the periodic array, which exhibits nonlocal electric field enhancement near the interface and high reflection. We achieve the reversible conversion between high reflection and high transmission by manipulating the interlayer coupling near the interface between the two magnetic mirrors. Controlling the interlayer spacing leads to the controllable interlayer coupling and scattering of meta-atom. The magnetic mirror effect boosts the interlayer coupling when the interlayer spacing is small. Furthermore, the high transmission of the bilayer metasurface has good robustness due to the meta-atom with interlayer coupling can maintain scattering suppression against positional perturbation. This work provides a straightforward method to design tunable metasurface and sheds new light on high-performance optical switches applied in communication and sensing.

8.
Int J Behav Nutr Phys Act ; 19(1): 151, 2022 12 13.
Artigo em Inglês | MEDLINE | ID: mdl-36514169

RESUMO

BACKGROUND: The associations of the proportion of vigorous physical activity (VPA) to moderate to vigorous physical activity (MVPA) with incident cardiovascular disease (CVD) and all-cause mortality are unclear. METHODS: The present study included 366,566 participants (aged 40-69 years) without baseline CVD from the UK biobank during 2006 to 2010. Cox regression was used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for risks of outcomes. RESULTS: During a median 11.8 years of follow-up, among 366,566 participants (mean age [SD]: 56.0 [8.1]), 31,894 incident CVD and 19,823 total deaths were documented. Compared with no VPA, 0%-30% of VPA to MVPA was associated with 12% and 19% lower risks of incident CVD (HR, 0.88 [95% CI, 0.86-0.91]) and all-cause mortality (HR, 0.81 [95% CI, 0.78-0.84]), respectively. Furthermore, we found that the maximum reduction of risks of incident CVD and all-cause mortality occurred at performing approximately 30% of VPA to MVPA (P < 0.001). Compared with participants reporting the lowest levels of MVPA (moderate physical activity [MPA], 0-150 min/week; VPA, 0-75 min/week), those performing 150-300 min/week of MPA and ≥ 150 min/week of VPA experienced the lowest risk of incident CVD (HR, 0.87 [95% CI, 0.79-0.95]) and all-cause mortality (HR, 0.71 [95% CI, 0.63-0.80]). Interestingly, we found that smokers yielded more cardiovascular benefits than non-smokers by performing a higher volume of VPA. CONCLUSIONS: Comparing with UK adults reporting no VPA, engaging in 30% of VPA was associated with the lowest risk of incident CVD and all-cause mortality.


Assuntos
Doenças Cardiovasculares , Humanos , Adulto , Estudos Prospectivos , Exercício Físico , Modelos de Riscos Proporcionais , Reino Unido/epidemiologia
9.
Org Biomol Chem ; 20(18): 3708-3711, 2022 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-35439808

RESUMO

An enantioselective metal-free hydrogenation of TIPS-protected oximes has been successfully realized for the first time by using chiral borane catalysts derived from chiral dienes and Piers' borane. A variety of hydroxylamine derivatives were afforded in 84-99% yields with 33-68% ees.


Assuntos
Boranos , Catálise , Hidrogenação , Oximas , Estereoisomerismo
10.
Proc Natl Acad Sci U S A ; 116(40): 19952-19962, 2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31515451

RESUMO

ANO1 (TMEM16A) is a Ca2+-activated Cl- channel that regulates diverse cellular functions including fluid secretion, neuronal excitability, and smooth muscle contraction. ANO1 is activated by elevation of cytosolic Ca2+ and modulated by phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2]. Here, we describe a closely concerted experimental and computational study, including electrophysiology, mutagenesis, functional assays, and extended sampling of lipid-protein interactions with molecular dynamics (MD) to characterize PI(4,5)P2 binding modes and sites on ANO1. ANO1 currents in excised inside-out patches activated by 270 nM Ca2+ at +100 mV are increased by exogenous PI(4,5)P2 with an EC50 = 1.24 µM. The effect of PI(4,5)P2 is dependent on membrane voltage and Ca2+ and is explained by a stabilization of the ANO1 Ca2+-bound open state. Unbiased atomistic MD simulations with 1.4 mol% PI(4,5)P2 in a phosphatidylcholine bilayer identified 8 binding sites with significant probability of binding PI(4,5)P2 Three of these sites captured 85% of all ANO1-PI(4,5)P2 interactions. Mutagenesis of basic amino acids near the membrane-cytosol interface found 3 regions of ANO1 critical for PI(4,5)P2 regulation that correspond to the same 3 sites identified by MD. PI(4,5)P2 is stabilized by hydrogen bonding between amino acid side chains and phosphate/hydroxyl groups on PI(4,5)P2 Binding of PI(4,5)P2 alters the position of the cytoplasmic extension of TM6, which plays a crucial role in ANO1 channel gating, and increases the accessibility of the inner vestibule to Cl- ions. We propose a model consisting of a network of 3 PI(4,5)P2 binding sites at the cytoplasmic face of the membrane allosterically regulating ANO1 channel gating.


Assuntos
Anoctamina-1/química , Cálcio/química , Proteínas de Neoplasias/química , Fosfatidilinositol 4,5-Difosfato/química , Sítios de Ligação , Cátions , Citosol/metabolismo , Eletrofisiologia , Células HEK293 , Humanos , Conformação Molecular , Simulação de Dinâmica Molecular , Mutagênese , Mutação , Técnicas de Patch-Clamp , Fosfolipídeos/química , Relação Estrutura-Atividade
11.
Ecotoxicol Environ Saf ; 241: 113705, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35687997

RESUMO

Limited studies have evaluated the associations of multiple metal exposures with homocysteine (Hcy) levels, which were independent risk factor for cardiovascular disease (CVD). Furthermore, the interactions between genetic variants and plasma metals in relation to Hcy levels were largely unknown. We aimed to explore the associations of multiple plasma metals (including metalloids arsenic [As] and selenium [Se]) with Hcy levels and whether their associations were modified by genetic susceptibility. We included 2989 participants from the baseline of the Dongfeng-Tongji cohort (DFTJ cohort) and conducted a cross-sectional study to explore the associations of 17 plasma metals with serum Hcy levels. Both multi-variable linear regression model (single-metal model) and LASSO penalized regression model (multiple-metal model) were used to identify the Hcy-associated metals. The weighted genetic risk score (GRS) was calculated based on 18 established Hcy-associated genetic variants. For metals that were associated with Hcy, we further assessed the gene-metal interactions on Hcy levels. Among 17 metals, plasma molybdenum (Mo), strontium (Sr), and Zinc (Zn) were positively associated with Hcy levels, whereas Se was inversely associated with Hcy levels in both single- and multiple-metal models. We also observed that the genetic predisposition to Hcy significantly modified the association between plasma Se and serum Hcy levels (P for interaction = 0.003), while no significant gene-metal interactions were found for Mo, Sr, and Zn (all P for interactions > 0.05). These findings provide novel insight into the associations of the plasma concentrations of Mo, Se, Sr and Zn with Hcy levels and address the importance of Se as a potential upstream modifiable factor for the personalized prevention of elevated Hcy levels and CVD.


Assuntos
Doenças Cardiovasculares , Selênio , Estudos Transversais , Predisposição Genética para Doença , Homocisteína , Humanos , Metais/toxicidade
12.
J Neurosci ; 40(3): 526-541, 2020 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-31754010

RESUMO

Neuronal dendrites have specialized actin-rich structures called dendritic spines that receive and integrate most excitatory synaptic inputs. The stabilization of dendrites and spines during neuronal maturation is essential for proper neural circuit formation. Changes in dendritic morphology and stability are largely mediated by regulation of the actin cytoskeleton; however, the underlying mechanisms remain to be fully elucidated. Here, we present evidence that the nebulin family members LASP1 and LASP2 play an important role in the postsynaptic development of rat hippocampal neurons from both sexes. We find that both LASP1 and LASP2 are enriched in dendritic spines, and their knockdown impairs spine development and synapse formation. Furthermore, LASP2 exerts a distinct role in dendritic arbor and dendritic spine stabilization. Importantly, the actin-binding N-terminal LIM domain and nebulin repeats of LASP2 are required for spine stability and dendritic arbor complexity. These findings identify LASP1 and LASP2 as novel regulators of neuronal circuitry.SIGNIFICANCE STATEMENT Proper regulation of the actin cytoskeleton is essential for the structural stability of dendrites and dendritic spines. Consequently, the malformation of dendritic structures accompanies numerous neurologic disorders, such as schizophrenia and autism. Nebulin family members are best known for their role in regulating the stabilization and function of actin thin filaments in muscle. The two smallest family members, LASP1 and LASP2, are more structurally diverse and are expressed in a broader array of tissues. While both LASP1 and LASP2 are highly expressed in the brain, little is currently known about their function in the nervous system. In this study, we demonstrate the first evidence that LASP1 and LASP2 are involved in the formation and long-term maintenance of dendrites and dendritic spines.


Assuntos
Proteínas com Domínio LIM/genética , Proteínas com Domínio LIM/fisiologia , Proteínas Musculares/genética , Proteínas Musculares/fisiologia , Domínios de Homologia de src/genética , Domínios de Homologia de src/fisiologia , Actinas/metabolismo , Animais , Dendritos/ultraestrutura , Espinhas Dendríticas/fisiologia , Espinhas Dendríticas/ultraestrutura , Potenciais Pós-Sinápticos Excitadores/genética , Técnicas de Silenciamento de Genes , Hipocampo/citologia , Hipocampo/crescimento & desenvolvimento , Proteínas dos Microfilamentos/genética , Proteínas dos Microfilamentos/fisiologia , Rede Nervosa/citologia , Rede Nervosa/crescimento & desenvolvimento , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/fisiologia , Neurônios/fisiologia , Técnicas de Patch-Clamp , Ratos
13.
Am J Epidemiol ; 190(9): 1821-1829, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-33728442

RESUMO

Present shift work has been associated with coronary heart disease (CHD) among employed workers, but it remains unclear whether shift work performed in the past is still associated with CHD in retired workers. We recruited 21,802 retired workers in Shiyan, China, in 2008-2010 and 2013 and followed them for CHD events occurring up to December 31, 2018. Retired workers with longer durations of past shift work (rounded to 0.25 years) had higher CHD risks (for those with ≤5.00, 5.25-10.00, 10.50-20.00, and >20.00 years of past shift work, hazard ratios were 1.05 (95% confidence interval (CI): 0.94, 1.16), 1.08 (95% CI: 0.94, 1.25), 1.23 (95% CI: 1.07, 1.42), and 1.28 (95% CI: 1.08, 1.51), respectively). The association was substantially higher among service or sales workers than among manufacturing or manual-labor workers (for every 5-year increase in past shift work, hazard ratio = 1.11 (95% CI: 1.05, 1.16) vs. hazard ratio = 1.02 (95% CI: 0.98, 1.06)). Moreover, the risk was lower among those who were physically active than among their inactive counterparts (P for interaction = 0.019). Longer duration of past shift work was associated with higher risk of incident CHD among these retired workers, especially those from the service or sales sectors. Physical exercise might be beneficial in reducing the excess risk.


Assuntos
Doença das Coronárias/etiologia , Aposentadoria/estatística & dados numéricos , Jornada de Trabalho em Turnos/efeitos adversos , China/epidemiologia , Doença das Coronárias/epidemiologia , Exercício Físico , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Risco , Jornada de Trabalho em Turnos/estatística & dados numéricos
14.
J Chem Phys ; 155(14): 144701, 2021 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-34654293

RESUMO

Metal nanoparticles are excellent acoustic resonators and their vibrational spectroscopy has been widely investigated. However, the coupling between vibrational modes of different nanoparticles is less explored. For example, how the intervening medium affects the coupling strength is not known. Here, we investigate how different polymers affect coupling in Au nanoplate-polymer-Au nanoplate sandwich structures. The coupling between the breathing modes of the Au nanoplates was measured using single-particle pump-probe spectroscopy, and the polymer dependent coupling strength was determined experimentally. Analysis of the acoustic mode coupling gives the effective spring constant for the polymers. A relative motion mode was also observed for the stacked Au nanoplates. The frequency of this mode is strongly correlated with the coupling constant for the breathing modes. The breathing mode coupling and relative motion mode were analyzed using a coupled oscillator model. This model shows that both these effects can be described using the same spring constant for the polymer. Finally, we present a new type of mass balance using the strongly coupled resonators. We show that the resonators have a mass detection limit of a few femtograms. We envision that further understanding of the vibrational coupling in acoustic resonators will improve the coupling strength and expand their potential applications.

15.
Cancer ; 126 Suppl 9: 2093-2100, 2020 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-32293729

RESUMO

BACKGROUND: New immunotherapeutic approaches are urgently needed for metastatic rhabdomyosarcoma, which is associated with poor survival and unsatisfactory treatment outcomes. Platelet-derived growth factor receptor α (PDGFRA) plays an essential role in the onset and development of rhabdomyosarcoma and is a new potential therapeutic target for rhabdomyosarcoma. The objective of this study was to generate humanized PDGFRA single-chain variable fragment-based chimeric antigen receptor (CAR)-modified T cells (CAR-T cells) against PDGFRA-positive rhabdomyosarcoma. METHODS: PDGFRA antigen expression was evaluated in specimens from patients with rhabdomyosarcoma. CAR-T cells containing a PDGFRA-specific single-chain variable fragment was developed in combination with a 4-1BB costimulatory domain and a CD3-ζ signaling domain. Specific cytotoxic effects of PDGFRA CAR-T cells, T-cell proliferation, and cytokine secretion were investigated in vitro and in vivo. RESULTS: PDGFRA CAR-T cells produced large amounts of immune-promoting cytokines, including interleukin 2, tumor necrosis factor α, and interferon γ, and exhibited efficient cytotoxic activity toward human PDGFRA-overexpressing rhabdomyosarcoma cells in vitro. In a subcutaneous xenograft model, CAR-T cells were more effective against PDGFRA-overexpressing rhabdomyosarcoma than against rhabdomyosarcoma with low PDGFRA expression in terms of tumor regression and patient survival. Expanded CAR-T cells also were detected in peripheral blood. CONCLUSIONS: The current study demonstrates for the first time that the PDGFRA antigen is a promising target for CAR-T-cell therapy in rhabdomyosarcoma and likely in a wide spectrum of other PDGFRA-expressing cancers.


Assuntos
Receptores de Antígenos Quiméricos , Rabdomiossarcoma Embrionário , Rabdomiossarcoma , Anticorpos de Cadeia Única , Linhagem Celular Tumoral , Terapia Baseada em Transplante de Células e Tecidos , Humanos , Imunoterapia Adotiva , Receptores de Antígenos Quiméricos/genética , Receptores do Fator de Crescimento Derivado de Plaquetas , Rabdomiossarcoma/genética , Rabdomiossarcoma/terapia , Anticorpos de Cadeia Única/metabolismo
16.
Proc Natl Acad Sci U S A ; 114(5): 962-967, 2017 01 31.
Artigo em Inglês | MEDLINE | ID: mdl-28096386

RESUMO

Fluorescence imaging multiplicity of biological systems is an area of intense focus, currently limited to fluorescence channels in the visible and first near-infrared (NIR-I; ∼700-900 nm) spectral regions. The development of conjugatable fluorophores with longer wavelength emission is highly desired to afford more targeting channels, reduce background autofluorescence, and achieve deeper tissue imaging depths. We have developed NIR-II (1,000-1,700 nm) molecular imaging agents with a bright NIR-II fluorophore through high-efficiency click chemistry to specific molecular antibodies. Relying on buoyant density differences during density gradient ultracentrifugation separations, highly pure NIR-II fluorophore-antibody conjugates emitting ∼1,100 nm were obtained for use as molecular-specific NIR-II probes. This facilitated 3D staining of ∼170-µm histological brain tissues sections on a home-built confocal microscope, demonstrating multicolor molecular imaging across both the NIR-I and NIR-II windows (800-1,700 nm).


Assuntos
Química Encefálica , Encéfalo/ultraestrutura , Química Click , Técnica Direta de Fluorescência para Anticorpo/métodos , Corantes Fluorescentes/análise , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Animais , Biotinilação , Carcinoma de Células Escamosas/ultraestrutura , Cetuximab/análise , Imageamento Tridimensional , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Microscopia Confocal/métodos , Estrutura Molecular , Nanotubos , Ressonância Magnética Nuclear Biomolecular , Estreptavidina
17.
J Neurosci ; 38(48): 10271-10285, 2018 11 28.
Artigo em Inglês | MEDLINE | ID: mdl-30301754

RESUMO

Neurons of the CNS elaborate highly branched dendritic arbors that host numerous dendritic spines, which serve as the postsynaptic platform for most excitatory synapses. The actin cytoskeleton plays an important role in dendrite development and spine formation, but the underlying mechanisms remain incompletely understood. Tropomodulins (Tmods) are a family of actin-binding proteins that cap the slow-growing (pointed) end of actin filaments, thereby regulating the stability, length, and architecture of complex actin networks in diverse cell types. Three members of the Tmod family, Tmod1, Tmod2, and Tmod3 are expressed in the vertebrate CNS, but their function in neuronal development is largely unknown. In this study, we present evidence that Tmod1 and Tmod2 exhibit distinct roles in regulating spine development and dendritic arborization, respectively. Using rat hippocampal tissues from both sexes, we find that Tmod1 and Tmod2 are expressed with distinct developmental profiles: Tmod2 is expressed early during hippocampal development, whereas Tmod1 expression coincides with synaptogenesis. We then show that knockdown of Tmod2, but not Tmod1, severely impairs dendritic branching. Both Tmod1 and Tmod2 are localized to a distinct subspine region where they regulate local F-actin stability. However, the knockdown of Tmod1, but not Tmod2, disrupts spine morphogenesis and impairs synapse formation. Collectively, these findings demonstrate that regulation of the actin cytoskeleton by different members of the Tmod family plays an important role in distinct aspects of dendrite and spine development.SIGNIFICANCE STATEMENT The Tropomodulin family of molecules is best known for controlling the length and stability of actin myofilaments in skeletal muscles. While several Tropomodulin members are expressed in the brain, fundamental knowledge about their role in neuronal function is limited. In this study, we show the unique expression profile and subcellular distribution of Tmod1 and Tmod2 in hippocampal neurons. While both Tmod1 and Tmod2 regulate F-actin stability, we find that they exhibit isoform-specific roles in dendrite development and synapse formation: Tmod2 regulates dendritic arborization, whereas Tmod1 is required for spine development and synapse formation. These findings provide novel insight into the actin regulatory mechanisms underlying neuronal development, thereby shedding light on potential pathways disrupted in a number of neurological disorders.


Assuntos
Dendritos/fisiologia , Hipocampo/crescimento & desenvolvimento , Sinapses/fisiologia , Tropomodulina/fisiologia , Animais , Células Cultivadas , Dendritos/química , Feminino , Hipocampo/química , Hipocampo/citologia , Masculino , Neurônios/química , Neurônios/fisiologia , Gravidez , Isoformas de Proteínas/química , Isoformas de Proteínas/fisiologia , Ratos , Ratos Sprague-Dawley , Sinapses/química
18.
Circ Res ; 120(11): 1754-1767, 2017 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-28348007

RESUMO

RATIONALE: Acute coronary syndrome (ACS) is a leading cause of death worldwide. Immune functions play a vital role in ACS development; however, whether epigenetic modulation contributes to the regulation of blood immune cells in this disease has not been investigated. OBJECTIVE: We conducted an epigenome-wide analysis with circulating immune cells to identify differentially methylated genes in ACS. METHODS AND RESULTS: We examined genome-wide methylation of whole blood in 102 ACS patients and 101 controls using HumanMethylation450 array, and externally replicated significant discoveries in 100 patients and 102 controls. For the replicated loci, we further analyzed their association with ACS in 6 purified leukocyte subsets, their correlation with the expressions of annotated genes, and their association with cardiovascular traits/risk factors. We found novel and reproducible association of ACS with blood methylation at 47 cytosine-phosphoguanine sites (discovery: false discovery rate <0.005; replication: Bonferroni corrected P<0.05). The association of methylation levels at these cytosine-phosphoguanine sites with ACS was further validated in at least 1 of the 6 leukocyte subsets, with predominant contributions from CD8+ T cells, CD4+ T cells, and B cells. Blood methylation of 26 replicated cytosine-phosphoguanine sites showed significant correlation with expressions of annotated genes (including IL6R, FASLG, and CCL18; P<5.9×10-4), and differential gene expression in case versus controls corroborated the observed differential methylation. The replicated loci suggested a role in ACS-relevant functions including chemotaxis, coronary thrombosis, and T-cell-mediated cytotoxicity. Functional analysis using the top ACS-associated methylation loci in purified T and B cells revealed vital pathways related to atherogenic signaling and adaptive immune response. Furthermore, we observed a significant enrichment of the replicated cytosine-phosphoguanine sites associated with smoking and low-density lipoprotein cholesterol (Penrichment≤1×10-5). CONCLUSIONS: Our study identified novel blood methylation alterations associated with ACS and provided potential clinical biomarkers and therapeutic targets. Our results may suggest that immune signaling and cellular functions might be regulated at an epigenetic level in ACS.


Assuntos
Síndrome Coronariana Aguda/sangue , Síndrome Coronariana Aguda/genética , Metilação de DNA/fisiologia , Epigênese Genética/fisiologia , Estudo de Associação Genômica Ampla/métodos , Síndrome Coronariana Aguda/epidemiologia , Idoso , Estudos de Casos e Controles , China/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
19.
Nanotechnology ; 30(48): 485701, 2019 11 29.
Artigo em Inglês | MEDLINE | ID: mdl-31437820

RESUMO

Monolayer MoS2 as a member of two-dimensional transition metal dichalcogenides (TMDs) has attracted considerable attention due to its superior optoelectronic properties. Understanding the photocarrier dynamics and transport in these two dimensional systems is beneficial for applications from photovoltaics to sensing. However, various structural defects strongly impact the dynamics and transport of photocarriers. Especially there lacks a precise measuring and understanding of photocarrier transport in TMDs. Here, femtosecond transient absorption spectroscopy and microscopy were employed to study the photocarrier dynamics and transport in monolayer MoS2. Defect correlated photocarrier dynamics are observed across the monolayer MoS2 where exciton formation and nonradiative recombination are the two dominant decay processes. To the best of our knowledge, we report two distinct photocarrier transport regimes in MoS2 for the first time with diffusion coefficients of [Formula: see text] cm2 s-1 and [Formula: see text] cm2 s-1, by taking advantages of ultrafast microscopy with ∼20 nm spatial precision and ∼200 fs temporal resolution. These two regimes are ascribed to fast hot photocarrier diffusion and slow phonon-limited thermal diffusion, respectively. The results indicate that the initial fast photocarrier transport is less dependent on structural defects compared to photocarrier relaxation dynamics which may be useful for hot photocarrier extraction applications.

20.
J Phys Chem A ; 123(47): 10339-10346, 2019 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-31692355

RESUMO

Radiation losses due to energy transfer to acoustic waves in the surroundings lead to short vibrational lifetimes of plasmonic nanoresonators and severely limits their applications in quantum technologies and mass sensing. Here we demonstrate a general method for improving the acoustic vibration lifetimes of Au nanoplates (flat structures with edge lengths of several microns and thicknesses of 10-40 nm) by using unsupported thin films instead of thick substrates, which blocks the outgoing acoustic waves. We experimentally confirm the vibrational quality factor improvement of Au nanoplates on Si3N4 and Al2O3/Si3N4 thin films with thicknesses less than 100 nm. Through this substrate phonon engineering, we successfully observe strong vibrational coupling between two Au nanoplates. Furthermore, the increased vibrational lifetimes allow us to study the vibrations of the nanoplates relative to the substrate and, for stacked nanoplates, relative to each other. The frequencies of these relative vibrational modes are well described by a simple coupled mass model, which provides the effective spring constants between interfaces separated by surface bonded molecules. We also demonstrate that the continuous thin films can be used for small plasmonic nanostructures (dimensions of several hundred nm), with similar increases in the vibrational lifetimes.

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