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1.
Proc Natl Acad Sci U S A ; 113(20): E2832-41, 2016 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-27140632

RESUMO

In Caenorhabditis elegans, removing germ cells slows aging and extends life. Here we show that transcription factors that extend life and confer protection to age-related protein-aggregation toxicity are activated early in adulthood in response to a burst of reactive oxygen species (ROS) and a shift in sulfur metabolism. Germline loss triggers H2S production, mitochondrial biogenesis, and a dynamic pattern of ROS in specific somatic tissues. A cytoskeletal protein, KRI-1, plays a key role in the generation of H2S and ROS. These kri-1-dependent redox species, in turn, promote life extension by activating SKN-1/Nrf2 and the mitochondrial unfolded-protein response, respectively. Both H2S and, remarkably, kri-1-dependent ROS are required for the life extension produced by low levels of the superoxide-generator paraquat and by a mutation that inhibits respiration. Together our findings link reproductive signaling to mitochondria and define an inducible, kri-1-dependent redox-signaling module that can be invoked in different contexts to extend life and counteract proteotoxicity.


Assuntos
Envelhecimento , Caenorhabditis elegans/fisiologia , Sulfeto de Hidrogênio/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Transporte Ativo do Núcleo Celular , Animais , Caenorhabditis elegans/citologia , Proteínas de Caenorhabditis elegans/metabolismo , Proteínas de Ligação a DNA/metabolismo , Células Germinativas/fisiologia , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Longevidade , Dinâmica Mitocondrial , Biogênese de Organelas , Oxirredução , Transdução de Sinais , Fatores de Transcrição/metabolismo
2.
Tumour Biol ; 37(4): 5599-607, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26577855

RESUMO

The aim was to analyze quantitative (mitochondrial DNA (mtDNA) content) and qualitative (G10398A polymorphism) mtDNA alterations as well as human papillomavirus (HPV) infection in cervical cancer prognosis. One hundred and twenty-two cases of formalin-fixed paraffin-embedded cervical carcinoma specimens were collected from the Yichang Tumor Hospital and Zhongnan Hospital of Wuhan University in the recent 10 years together with medical records. A quantitative real-time PCR (RT-PCR) was used to determine the copy number of the mitochondrial DNA and HPV expression levels. G10398A polymorphism was determined by PCR-RFLP assay. The overall survival of patients with higher mtDNA content was significantly reduced compared with lower mtDNA content patients (P = 0.029). But there was no difference of prognosis between the mtDNA 10398 A allele and G allele. However, the Kaplan-Meier survival curve illustrated a significantly reduced overall survival in the patients with 10398A plus high mtDNA copy number compared with the other groups (P < 0.05). Although no association between HPV expression level and cervical cancer prognosis was observed, 10398A got increased mtDNA content compared with 10398G (P < 0.05) and 10398G displayed an increased HPV-positive rate compared with 10398A. Furthermore, HPV-18 and mtDNA content were positively related in the younger subgroup (≤45 years) (correlation coefficient = 0.456, P = 0.022). This study indicated that mtDNA content and HPV infection status are associated with cervical cancer prognosis. High mitochondrial DNA content plus 10398 A may be a marker of poor prognosis in cervical cancer. And mtDNA variation may potentially influence the predisposition to HPV infection and cervical carcinogenesis.


Assuntos
DNA Mitocondrial/genética , Infecções por Papillomavirus/genética , Prognóstico , Neoplasias do Colo do Útero/genética , Idoso , Idoso de 80 Anos ou mais , Alelos , DNA Mitocondrial/isolamento & purificação , Feminino , Genótipo , Papillomavirus Humano 18/genética , Papillomavirus Humano 18/patogenicidade , Humanos , Estimativa de Kaplan-Meier , Pessoa de Meia-Idade , Infecções por Papillomavirus/patologia , Infecções por Papillomavirus/virologia , Polimorfismo de Nucleotídeo Único/genética , Fatores de Risco , Neoplasias do Colo do Útero/patologia
3.
Cancer Sci ; 105(6): 639-45, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24703408

RESUMO

It has been reported that quantitative alterations and sequence variations of mtDNA are associated with the onset and progression of particular types of tumor. However, the relationship between mtDNA content, certain mtDNA polymorphisms in peripheral blood leukocytes and breast cancer risk remain obscure. This study was undertaken to investigate whether mtDNA content and the A10398G polymorphism in peripheral blood leukocytes could be used as risk predictors for breast cancer in Han Chinese women. Blood samples were obtained from a total of 506 breast cancer patients and 520 matched healthy controls. The mtDNA content was measured by using quantitative real-time PCR assay; A10398G polymorphism was determined by PCR-RFLP assay. There was no statistically significant difference between cases and controls in terms of peripheral blood mtDNA content or A10398G polymorphism. However, further analysis suggested that the risk of breast cancer was associated with decreased mtDNA content in premenopausal women (P = 0.001; odds ratio = 0.54; 95% confidence interval, 0.38-0.77), with increased mtDNA content in postmenopausal women (P = 0.027; odds ratio = 1.49; 95% confidence interval, 1.05-2.11). In addition, the associations between mtDNA content and several clinicopathological parameters of cases such as age, menopausal status, and number of pregnancies and live births were observed. This case-control study indicated that the peripheral blood mtDNA content might be a potential biomarker to evaluate the risk of breast cancer for selected Chinese women.


Assuntos
Neoplasias da Mama/genética , DNA Mitocondrial/sangue , DNA Mitocondrial/genética , Predisposição Genética para Doença , Mitocôndrias/genética , Biomarcadores Tumorais/genética , Neoplasias da Mama/epidemiologia , Estudos de Casos e Controles , China/epidemiologia , Feminino , Variação Genética , Genótipo , Humanos , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Pré-Menopausa/genética , Risco
4.
Huan Jing Ke Xue ; 45(1): 123-130, 2024 Jan 08.
Artigo em Chinês | MEDLINE | ID: mdl-38216464

RESUMO

Based on the actual operating conditions and data monitoring, the carbon emission characteristics of typical processes of a drinking water treatment plant (DWTP) in Tianjin were studied. The total carbon emission intensity measured by CO2-eq was 0.254 kg·m-3, and the proportion of carbon emissions from electricity consumption and reagent consumption was 81.76% and 9.15%, respectively. The key carbon emission sectors of electricity consumption were the water supply pump house, ultrafiltration membrane process, and inlet pump house, which accounted for 50.99%-73.51%, 17.64%-20.70%, and 17.97%-22.40% of the total carbon emission from electricity consumption in the DWTP, respectively. The contribution of sodium hypochlorite to the carbon emission of reagent consumption was 89.12%-90.30%, followed by ferric chloride, PAC, and ammonium sulfate. In the traditional water purification process, the carbon emission intensity of the process unit was in the order of inlet pump house > rapid filter > sedimentation tank. The order in the ultrafiltration membrane advanced treatment process was inlet pump house > ultrafiltration membrane > mechanical coagulation > clarification tank. The carbon emission intensity of the rapid filter process and the ultrafiltration membrane process were 0.070 9 kg·m-3 and 0.109 0 kg·m-3, respectively. The ultrafiltration membrane process could save 23% of the reagent consumption, and its carbon emission of electricity consumption was twice that of the traditional treatment process. The analysis of factors affecting carbon emission in key sectors showed that the raw water quality parameters such as turbidity, pH, ammonia nitrogen, temperature, etc., were significantly correlated with the carbon emission intensity of sodium hypochlorite. There was a significant linear regression relationship between ex-factory water pressure, daily water supply, and carbon emission intensity of the water supply pump house. The control measures of water quality and water pressure can effectively reduce the carbon emissions of the DWTP.


Assuntos
Água Potável , Purificação da Água , Carbono , Hipoclorito de Sódio , Abastecimento de Água , Ultrafiltração
5.
PLoS One ; 19(3): e0300135, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38547109

RESUMO

Peptides present an alternative modality to immunoglobulin domains or small molecules for developing therapeutics to either agonize or antagonize cellular pathways associated with diseases. However, peptides often suffer from poor chemical and physical stability, limiting their therapeutic potential. Disulfide-constrained peptides (DCP) are naturally occurring and possess numerous desirable properties, such as high stability, that qualify them as drug-like scaffolds for peptide therapeutics. DCPs contain loop regions protruding from the core of the molecule that are amenable to peptide engineering via direct evolution by use of phage display technology. In this study, we have established a robust platform for the discovery of peptide therapeutics using various DCPs as scaffolds. We created diverse libraries comprising seven different DCP scaffolds, resulting in an overall diversity of 2 x 1011. The effectiveness of this platform for functional hit discovery has been extensively evaluated, demonstrating a hit rate comparable to that of synthetic antibody libraries. By utilizing chemically synthesized and in vitro folded peptides derived from selections of phage displayed DCP libraries, we have successfully generated functional inhibitors targeting the HtrA1 protease. Through affinity maturation strategies, we have transformed initially weak binders against Notch2 with micromolar Kd values to high-affinity ligands in the nanomolar range. This process highlights a viable hit-to-lead progression. Overall, our platform holds significant potential to greatly enhance the discovery of peptide therapeutics.


Assuntos
Dissulfetos , Peptídeos , Peptídeos/farmacologia , Peptídeos/química , Biblioteca de Peptídeos , Peptídeo Hidrolases
6.
Nat Commun ; 15(1): 4359, 2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38777835

RESUMO

Cystine-knot peptides (CKPs) are naturally occurring peptides that exhibit exceptional chemical and proteolytic stability. We leveraged the CKP carboxypeptidase A1 inhibitor as a scaffold to construct phage-displayed CKP libraries and subsequently screened these collections against HTRA1, a trimeric serine protease implicated in age-related macular degeneration and osteoarthritis. The initial hits were optimized by using affinity maturation strategies to yield highly selective and potent picomolar inhibitors of HTRA1. Crystal structures, coupled with biochemical studies, reveal that the CKPs do not interact in a substrate-like manner but bind to a cryptic pocket at the S1' site region of HTRA1 and abolish catalysis by stabilizing a non-competent active site conformation. The opening and closing of this cryptic pocket is controlled by the gatekeeper residue V221, and its movement is facilitated by the absence of a constraining disulfide bond that is typically present in trypsin fold serine proteases, thereby explaining the remarkable selectivity of the CKPs. Our findings reveal an intriguing mechanism for modulating the activity of HTRA1, and highlight the utility of CKP-based phage display platforms in uncovering potent and selective inhibitors against challenging therapeutic targets.


Assuntos
Domínio Catalítico , Serina Peptidase 1 de Requerimento de Alta Temperatura A , Peptídeos , Serina Peptidase 1 de Requerimento de Alta Temperatura A/metabolismo , Serina Peptidase 1 de Requerimento de Alta Temperatura A/genética , Humanos , Peptídeos/química , Peptídeos/metabolismo , Peptídeos/farmacologia , Biblioteca de Peptídeos , Cristalografia por Raios X , Ligação Proteica , Cistina/química , Cistina/metabolismo , Modelos Moleculares
7.
EMBO J ; 28(15): 2220-30, 2009 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-19574957

RESUMO

We have found earlier that Tor1 binds to 5S rDNA chromatin but the functional significance has not been established. Here, we show that association with 5S rDNA chromatin is necessary for TOR complex 1 (TORC1) to regulate the synthesis of 5S ribosomal RNA and transfer RNAs (tRNAs) by RNA polymerase (Pol) III, as well as the phosphorylation and binding to Pol III-transcribed genes of the Pol III repressor Maf1. Interestingly, TORC1 does not bind to tRNA genes, suggesting that TORC1 modulates tRNA synthesis indirectly through Maf1 phosphorylation at the rDNA loci. We also find that Maf1 cytoplasmic localization is dependent on the SSD1-v allele. In W303 cells that carry the SSD1-d allele, Maf1 is constitutively nuclear but its nucleolar localization is inhibited by TORC1, indicating that TORC1 regulates nucleoplasm-to-nucleolus transport of Maf1. Finally, we show that TORC1 interacts with Maf1 in vivo and phosphorylates Maf1 in vitro, and regulates Maf1 nucleoplasm-to-nucleolus translocation. Together, these observations provide new insights into the chromatin-dependent mechanism by which TORC1 controls transcription by Pol III.


Assuntos
DNA Ribossômico/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , RNA Polimerase III/metabolismo , RNA Ribossômico 5S/biossíntese , RNA de Transferência/biossíntese , Proteínas de Saccharomyces cerevisiae/metabolismo , Fatores de Transcrição/metabolismo , Transcrição Gênica , Regulação Fúngica da Expressão Gênica , Modelos Biológicos , Fosforilação , Ligação Proteica , Saccharomyces cerevisiae/fisiologia
8.
Biogerontology ; 14(4): 353-63, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23740528

RESUMO

TOR (target of rapamycin) pathway has been well known for its central role in growth control. Interestingly, recent studies also implicate the TOR pathway in lifespan regulation in various organisms ranging from budding yeast to mammals. TOR gains momentum in a study showing that rapamycin administration later in life significantly extends lifespan in mice. How the TOR kinase controls these two seemingly distinct biological processes is an especially intriguing question yet to be answered. Here, we summarize the literatures concerning TOR's role in growth control, stress response and lifespan regulation, hoping to obtain a better understanding of how cell growth and maintenance are balanced by TOR and how TOR-mediated shift in metabolisms or energy allocations may translate into lifespan extension at the organismal level. We also evaluate the undergoing efforts to target the TOR pathway for health in human, with focus on looking for new drugs that can bypass the unwanted side effects of rapamycin derivatives.


Assuntos
Longevidade , Serina-Treonina Quinases TOR/fisiologia , Adenilato Quinase/metabolismo , Animais , Estresse Oxidativo , Saccharomyces cerevisiae/crescimento & desenvolvimento , Saccharomyces cerevisiae/fisiologia
9.
Environ Sci Pollut Res Int ; 30(16): 47455-47469, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36740618

RESUMO

Assessing public preferences for air pollution control is essential to achieving effective air quality improvement, but the internal psychological factors affecting public preferences, especially psychological distance (PD), have only received limited attention. Therefore, this paper explores the role of PD in assessing public preferences for air quality improvement policies. Compared with previous studies that consider psychological factors in the choice model, this study incorporates PD into the choice model as a latent variable by considering both individual responses to measurement questions and socio-economic characteristics in the integrated choice and latent variable model. The results of this study clearly show that PD significantly affects public preferences for air quality improvement policies. Respondents with close PD had obvious preferences for air quality improvement, while those with distant PD were satisfied with the current situation and reluctant to improve it. After considering PD in the analysis, respondents' willingness to pay for one-unit level change of attributes "heavily polluted days," "good air days," "mortality," and "policy postponement" were respectively 10.3791CNY, 10.9005CNY, 11.0427CNY, 28.3412CNY per year. In addition, the paper also found men and respondents with lower levels of education and higher monthly incomes tended to view air pollution as psychologically distant and thus less willing to improve air quality. It is suggested that policy makers should reduce the PD of air pollution among these people by increasing publicity about the hazards of air pollution. This study not only contributes to the literature on the importance of PD in assessing individual preferences, but also provides constructive guidance for policy makers to assess the public's acceptability of air quality improvement.


Assuntos
Poluição do Ar , Distância Psicológica , Masculino , Humanos , Melhoria de Qualidade , Conservação dos Recursos Naturais , Políticas
10.
Sci Total Environ ; 868: 161436, 2023 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-36623658

RESUMO

Environmental information is a prerequisite for public participation in air quality improvement, and the choice of such participation behavior is influenced by the intervention of environmental information. Nonetheless, there has been insufficient analysis of how information interventions affect public preferences and willingness to pay for air quality improvement. The combination of deliberative and choice experiment is used to explore the importance of information interventions for public participation in air quality improvement, and the changes in public preferences and willingness to pay for air quality improvement before and after information interventions are compared to analyze the impact of information interventions on evaluation results of air quality value. The results suggest that information interventions do alter the preferences and willingness of the public to pay for air quality improvement, significantly increasing the choice certainty of respondents and decreasing the protest response. In addition, women and high-income groups showed a stronger willingness to improve air quality after the information interventions, with 35.15 CNY, 44.07 CNY and 46.75 CNY increases in willingness to pay for improved urban green coverage rate, fewer haze days and reduced morbidity. The combination of deliberative information interventions and choice experiment will help improve the effectiveness of air quality value evaluation, stimulate public environmental awareness and willingness to participate, and the results will aid government environmental management.


Assuntos
Poluição do Ar , Melhoria de Qualidade , Humanos , Feminino , Renda , Inquéritos e Questionários
11.
Nanomaterials (Basel) ; 13(12)2023 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-37368247

RESUMO

WTe2, a low-symmetry transition metal dichalcogenide, has broad prospects in functional device applications due to its excellent physical properties. When WTe2 flake is integrated into practical device structures, its anisotropic thermal transport could be affected greatly by the substrate, which matters a lot to the energy efficiency and functional performance of the device. To investigate the effect of SiO2/Si substrate, we carried out a comparative Raman thermometry study on a 50 nm-thick supported WTe2 flake (with κzigzag = 62.17 W·m-1·K-1 and κarmchair = 32.93 W·m-1·K-1), and a suspended WTe2 flake of similar thickness (with κzigzag = 4.45 W·m-1·K-1, κarmchair = 4.10 W·m-1·K-1). The results show that the thermal anisotropy ratio of supported WTe2 flake (κzigzag/κarmchair ≈ 1.89) is about 1.7 times that of suspended WTe2 flake (κzigzag/κarmchair ≈ 1.09). Based on the low symmetry nature of the WTe2 structure, it is speculated that the factors contributing to thermal conductivity (mechanical properties and anisotropic low-frequency phonons) may have affected the thermal conductivity of WTe2 flake in an uneven manner when supported on a substrate. Our findings could contribute to the 2D anisotropy physics and thermal transport study of functional devices based on WTe2 and other low-symmetry materials, which helps solve the heat dissipation problem and optimize thermal/thermoelectric performance for practical electronic devices.

12.
Adv Sci (Weinh) ; 9(9): e2103429, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34970845

RESUMO

Low symmetric two dimensional (2D) semiconductors are of great significance for their potential applications in polarization-sensitive photodetection and quantum information devices. However, their real applications are limited by their photo-detecting wavelength ranges, which are restricted by their fundamental optical bandgaps. Recently, intercalation has been demonstrated to be a powerful strategy to modulate the optical bandgaps of 2D semiconductors. Here, the authors report the self-driven oxygen (O2 ) intercalation induced bandgap reduction from 1.75 to 1.19 eV in gallium telluride (GaTe) in air. This bandgap shrinkage provides the long-wavelength detection threshold above ≈1100 nm for O2 intercalated GaTe (referred to as GaTeO2 ), well beyond the cut-off wavelength at ≈708 nm for pristine GaTe. The GaTeO2 photodetectors have a high photoresponsivity, and highly anisotropic photodetection behavior to even sub-waveband radiation. The dichroic ratio (Imax /Imin ) of photocurrent is about 1.39 and 2.9 for 600 nm and 1100 nm, respectively. This findings demonstrates a broadband photodetector utilizing GaTe after breaking through its bandgap limitation by self-driven O2 intercalation in air and further reveal its photoconductivity anisotropic nature. This provides design strategies of 2D materials-based high-performance broadband photodetectors for the exploration of polarized state information.

13.
ACS Appl Mater Interfaces ; 14(45): 51122-51129, 2022 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-36331247

RESUMO

Investigating the energy dissipation in micro- and nanoscale is fundamental to improve the performance and reliability of two-dimensional (2D) electronics. Recently, 2D platinum selenide (PtSe2) has drawn extensive attention in developing next-generation functional devices due to its distinctive fusion of versatile properties. Toward practical applications of PtSe2 devices, it is essential to understand the interfacial thermal properties between PtSe2 and its substrate. Among them, the thermal boundary conductance (TBC) has played a critical role for out-of-plane heat dissipation of PtSe2 devices. Here, we identify the energy dissipation behavior of multilayer PtSe2 devices and extract the actual TBC value of the PtSe2/SiO2 interface by Raman thermometry with electrical bias. The obtained TBC value is about 8.6 MW m-2 K-1, and it belongs to the low end of as-known solid-solid interfaces, suggesting possible applications regarding thermoelectric devices or others reliant on a large temperature gradient. Furthermore, the maximum current density of the PtSe2 device determines its threshold power, which is crucial for improving device design and guiding future applications. Therefore, we explore the electrical breakdown profile of the multilayer PtSe2 device, revealing the breakdown current density of 17.7 MA cm-2 and threshold power density of 0.2 MW cm-2, which are larger than typical values for commonly used aluminum and copper. These results provide key insights into the energy dissipation of PtSe2 devices and make PtSe2 an excellent candidate for thermal confinement applications and nanometer-thin interconnects, which will benefit the development of energy-efficient functional 2D devices.

14.
Mol Neurobiol ; 58(9): 4506-4519, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34076838

RESUMO

To identify potential regulators and investigate the molecular mechanism of macrophage polarization affecting astrocyte activation from the perspective of non-coding RNA regulation, we isolated mouse bone marrow mononuclear cells (BMMNCs)-induced macrophages toward M1 or M2a polarization. Long non-coding RNA NEAT1 and IL-33 expression levels were significantly upregulated in M2a macrophages; NEAT1 knockdown in M2a macrophages markedly reduced the protein levels of IL-33 and M2a markers, IL-4 and IL-13 concentrations, and the bacterial killing capacity of M2a macrophages. NEAT1 acted as a competing endogenous RNA (ceRNA) to regulate IL-33 expression by sponging miR-224-5p in M2a macrophages; NEAT1 knockdown upregulated miR-224-5p expression, while miR-224-5p inhibition increased the protein content and concentration of IL-33. miR-224-5p inhibition exerted the opposite effects on the protein levels of IL-33 and M2a markers, IL-4 and IL-13 concentrations, and the bacterial killing capacity of M2a macrophages compared to NEAT1 knockdown; the effects of NEAT1 knockdown were significantly reversed by miR-224-5p inhibition. M2a macrophage conditioned medium (CM) significantly suppressed the activation of A1 astrocytes. NEAT1 knockdown M2a macrophage CM led to enhanced A1 astrocyte activation while miR-224-5p-silenced M2a macrophage CM led to a blockade of A1 astrocyte activation; the effects of NEAT1 knockdown M2a macrophage CM on A1 astrocyte activation were significantly reversed by miR-224-5p inhibition in M2a macrophages. The NEAT1/miR-224-5p/IL-33 axis modulates macrophage M2a polarization, therefore affecting A1 astrocyte activation.


Assuntos
Astrócitos/metabolismo , Interleucina-33/metabolismo , Macrófagos/metabolismo , MicroRNAs/metabolismo , RNA Longo não Codificante/metabolismo , Transdução de Sinais/fisiologia , Animais , Astrócitos/citologia , Polaridade Celular , Ativação de Macrófagos , Macrófagos/citologia , Camundongos
15.
Nanomaterials (Basel) ; 11(10)2021 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-34685191

RESUMO

The coupling strength between two-dimensional (2D) materials and substrate plays a vital role on thermal transport properties of 2D materials. Here we systematically investigate the influence of vacuum thermal annealing on the temperature-dependence of in-plane Raman phonon modes in monolayer graphene supported on silicon dioxide substrate via Raman spectroscopy. Intriguingly, raising the thermal annealing temperature can significantly enlarge the temperature coefficient of supported monolayer graphene. The derived temperature coefficient of G band remains mostly unchanged with thermal annealing temperature below 473 K, while it increases from -0.030 cm-1/K to -0.0602 cm-1/K with thermal annealing temperature ranging from 473 K to 773 K, suggesting the great impact of thermal annealing on thermal transport in supported monolayer graphene. Such an impact might reveal the vital role of coupling strength on phonon scattering and on the thermal transport property of supported monolayer graphene. To further interpret the thermal annealing mechanism, the compressive stress in supported monolayer graphene, which is closely related to coupling strength and is studied through the temperature-dependent Raman spectra. It is found that the variation tendency for compressive stress induced by thermal annealing is the same as that for temperature coefficient, implying the intense connection between compressive stress and thermal transport. Actually, 773 K thermal annealing can result in 2.02 GPa compressive stress on supported monolayer graphene due to the lattice mismatch of graphene and substrate. This study proposes thermal annealing as a feasible path to modulate the thermal transport in supported graphene and to design future graphene-based devices.

16.
Cell Death Dis ; 12(7): 701, 2021 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-34262025

RESUMO

The mitochondrial DNA m.3243A > G mutation is well-known to cause a variety of clinical phenotypes, including diabetes, deafness, and osteoporosis. Here, we report isolation and expansion of urine-derived stem cells (USCs) from patients carrying the m.3243A > G mutation, which demonstrate bimodal heteroplasmy. USCs with high levels of m.3243A > G mutation displayed abnormal mitochondrial morphology and function, as well as elevated ATF5-dependent mitochondrial unfolded protein response (UPRmt), together with reduced Wnt/ß-catenin signaling and osteogenic potentials. Knockdown of ATF5 in mutant USCs suppressed UPRmt, improved mitochondrial function, restored expression of GSK3B and WNT7B, and rescued osteogenic potentials. These results suggest that ATF5-dependent UPRmt could be a core disease mechanism underlying mitochondrial dysfunction and osteoporosis related to the m.3243A > G mutation, and therefore could be a novel putative therapeutic target for this genetic disorder.


Assuntos
Fatores Ativadores da Transcrição/genética , DNA Mitocondrial/genética , Mitocôndrias/genética , Doenças Mitocondriais/genética , Mutação , Osteoporose/genética , Células-Tronco/metabolismo , Fatores Ativadores da Transcrição/metabolismo , Adulto , Estudos de Casos e Controles , Separação Celular , Células Cultivadas , Análise Mutacional de DNA , Feminino , Predisposição Genética para Doença , Glicogênio Sintase Quinase 3 beta/genética , Glicogênio Sintase Quinase 3 beta/metabolismo , Heteroplasmia , Humanos , Masculino , Mitocôndrias/metabolismo , Mitocôndrias/ultraestrutura , Doenças Mitocondriais/diagnóstico , Doenças Mitocondriais/urina , Osteogênese , Osteoporose/diagnóstico , Osteoporose/urina , Fenótipo , Células-Tronco/ultraestrutura , Resposta a Proteínas não Dobradas , Urina/citologia , Proteínas Wnt/genética , Proteínas Wnt/metabolismo , Via de Sinalização Wnt , Adulto Jovem
17.
RSC Adv ; 10(54): 32906-32918, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-35516513

RESUMO

Graphitic carbon nitride (g-C3N4) is a promising photocatalyst for environmental protection but its development is greatly limited for its application in dark Fenton-like reactions due to its extremely low specific surface area and lack of suitable active sites. Herein, for the first time, graphitic carbon nitride with large surface area and abundant defect sites was developed by tailoring oxygen via a simple and green method without any templates, namely, the calcination-hydrothermal-calcination successive treatment of melamine. The structure of the catalyst was characterized using several technologies, including XRD, SEM, TEM, N2-physisorption, FT-IR, Raman spectroscopy and XPS. The results revealed that it possessed a large specific surface area (ca. 236 m2 g-1), while changes in its structural properties such as the formation of new defect sites and change in the content of nitrogen atoms were observed. These properties were beneficial for the in situ activation of H2O2 toward reactive oxygen species, as confirmed by the reactive oxygen species capturing experiments. Furthermore, various influencing factors were systemically investigated. The results clearly showed that the oxygen-doped g-C3N4 was light-independent and metal-free Fenton-like catalyst for the enhanced degradation of organic pollutants in wastewater. Compared to the pristine g-C3N4, the oxygen-doped g-C3N4 showed superior performance under various conditions such as broad pH range and excellent stability. Thus, this study provides a novel pathway for the treatment of organic pollutants in water.

18.
Aging (Albany NY) ; 12(3): 2680-2697, 2020 02 06.
Artigo em Inglês | MEDLINE | ID: mdl-32028263

RESUMO

Caloric restriction (CR) or Dietary restriction (DR) is known to improve health and in many cases increases lifespan. However, its negative effect on reproduction has not been fully studied. Practicing CR/DR without adequate knowledge on its side effect may risk complications such as infertility, birth defect, or malnutrition. In this study, by using several CR strategies in C. elegans, we examine key functions of reproduction including embryonic development and larvae growth. We find that CR significantly decreases the survival of embryos and slows the growth of the offspring. We further determine that defect in oocyte but not sperm is responsible for the compromised reproduction under CR. Interestingly, adding methionine to the medium reverses the reproduction defects, but does not affect the long lifespan resulted from CR. The beneficial effect of methionine on reproduction requires the yolk protein vitellogenin. CR down-regulates vitellogenin expression, which can be reversed by supplementing methionine in the food. Lacking the yolk protein transport due to rme-2 mutation blocks methionine's beneficial effects. Our study has revealed a novel, methionine-mediated genetic pathway linking nutrient sensing to reproduction and suggested methionine as a potential food supplement to mitigate the side effect of CR.


Assuntos
Caenorhabditis elegans/fisiologia , Suplementos Nutricionais , Gema de Ovo/metabolismo , Ingestão de Energia , Longevidade , Metionina/farmacologia , Animais , Metionina/administração & dosagem
19.
ACS Appl Mater Interfaces ; 12(15): 17706-17712, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-32223146

RESUMO

The energy dissipation issue has become one of the greatest challenges of the modern electronic industry. Incorporating graphene into the electronic devices has been widely accepted as a promising approach to solve this issue, due to its superior carrier mobility and thermal conductivity. Here, using Raman spectroscopy and infrared thermal microscopy, we identify the energy dissipation behavior of graphene device with different thicknesses. Surprisingly, the monolayer graphene device is demonstrated to have a comparable energy dissipation efficiency per unit volume with that of a few-layer graphene device. This has overturned the traditional understanding that the energy dissipation efficiency will reduce with the decrease of functional materials dimensions. Additionally, the energy dissipation speed of the monolayer graphene device is very fast, promising for devices with high operating frequency. Our finding provides a new insight into the energy dissipation issue of two-dimensional materials devices, which will have a global effect on the development of the electronic industry.

20.
Front Biosci (Landmark Ed) ; 25(9): 1765-1786, 2020 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-32472757

RESUMO

Placental alkaline phosphatase, PLAP encoded by ALPP gene in humans is mainly expressed in placenta and testis, and not expressed in any other normal tissues. PLAP is overexpressed in colorectal cancers which makes it an attractive target for CAR (chimeric antigen receptor)-T cell therapy. PLAP mRNA expression was detected in 21.5% (25 out of 116) of colorectal cancer cell lines and this expression was confirmed by FACS at the protein level. In addition, IHC staining on primary colorectal cancer tumors demonstrated PLAP expression in >20% of colorectal cancer tumors. We generated mouse and humanized PLAP ScFv-CAR-T cells and demonstrated high specificity against PLAP-positive colon cancer cells using RTCA (real-time cytotoxicity assay) and IFN-gamma secretion. In addition, humanized-CAR-T cells significantly decreased Lovo xenograft tumor growth in vivo. The combination of hPLAP-CAR-T cells with PD-1, PD-L1 or LAG-3 checkpoint inhibitors significantly increased the activity of hPLAP-CAR-T cells. This study demonstrates ability of novel PLAP-CAR-T cells to kill colorectal cancers and that the extent of killing can be increased by combination with checkpoint inhibitors.


Assuntos
Fosfatase Alcalina/imunologia , Neoplasias do Colo/imunologia , Isoenzimas/imunologia , Receptores de Antígenos Quiméricos/imunologia , Anticorpos de Cadeia Única/imunologia , Linfócitos T/imunologia , Fosfatase Alcalina/antagonistas & inibidores , Fosfatase Alcalina/metabolismo , Animais , Células CACO-2 , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/imunologia , Neoplasias do Colo/metabolismo , Neoplasias do Colo/terapia , Proteínas Ligadas por GPI/antagonistas & inibidores , Proteínas Ligadas por GPI/imunologia , Proteínas Ligadas por GPI/metabolismo , Células HCT116 , Células HEK293 , Células HT29 , Humanos , Inibidores de Checkpoint Imunológico/farmacologia , Imunoterapia Adotiva/métodos , Interferon gama/imunologia , Interferon gama/metabolismo , Isoenzimas/antagonistas & inibidores , Isoenzimas/metabolismo , Masculino , Camundongos Endogâmicos NOD , Camundongos Knockout , Camundongos SCID , Receptores de Antígenos Quiméricos/metabolismo , Anticorpos de Cadeia Única/metabolismo , Linfócitos T/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto/métodos
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