Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 9 de 9
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
PLoS Pathog ; 20(9): e1012535, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39255317

RESUMO

Kaposi's sarcoma-associated herpesvirus (KSHV) is a double-stranded DNA virus that encodes numerous cellular homologs, including cyclin D, G protein-coupled protein, interleukin-6, and macrophage inflammatory proteins 1 and 2. KSHV vCyclin encoded by ORF72, is the homolog of cellular cyclinD2. KSHV vCyclin can regulate virus replication and cell proliferation by constitutively activating cellular cyclin-dependent kinase 6 (CDK6). However, the regulatory mechanism of KSHV vCyclin has not been fully elucidated. In the present study, we identified a host protein named protein arginine methyltransferase 5 (PRMT5) that interacts with KSHV vCyclin. We further demonstrated that PRMT5 is upregulated by latency-associated nuclear antigen (LANA) through transcriptional activation. Remarkably, knockdown or pharmaceutical inhibition (using EPZ015666) of PRMT5 inhibited the cell cycle progression and cell proliferation of KSHV latently infected tumor cells. Mechanistically, PRMT5 methylates vCyclin symmetrically at arginine 128 and stabilizes vCyclin in a methyltransferase activity-dependent manner. We also show that the methylation of vCyclin by PRMT5 positively regulates the phosphorylate retinoblastoma protein (pRB) pathway. Taken together, our findings reveal an important regulatory effect of PRMT5 on vCyclin that facilitates cell cycle progression and proliferation, which provides a potential therapeutic target for KSHV-associated malignancies.


Assuntos
Ciclo Celular , Proliferação de Células , Herpesvirus Humano 8 , Proteína-Arginina N-Metiltransferases , Proteína-Arginina N-Metiltransferases/metabolismo , Proteína-Arginina N-Metiltransferases/genética , Humanos , Herpesvirus Humano 8/metabolismo , Herpesvirus Humano 8/fisiologia , Metilação , Antígenos Virais/metabolismo , Antígenos Virais/genética , Proteínas Virais/metabolismo , Proteínas Virais/genética , Ciclina D2/metabolismo , Células HEK293 , Replicação Viral/fisiologia , Sarcoma de Kaposi/virologia , Sarcoma de Kaposi/metabolismo , Proteínas Nucleares
2.
J Virol ; 98(2): e0156723, 2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38197631

RESUMO

Kaposi's sarcoma-associated herpesvirus (KSHV) belongs to the gamma herpesvirus family, which can cause human malignancies including Kaposi sarcoma, primary effusion lymphoma, and multicentric Castleman's diseases. KSHV typically maintains a persistent latent infection within the host. However, after exposure to intracellular or extracellular stimuli, KSHV lytic replication can be reactivated. The reactivation process of KSHV triggers the innate immune response to limit viral replication. Here, we found that the transcriptional regulator RUNX3 is transcriptionally upregulated by the NF-κB signaling pathway in KSHV-infected SLK cells and B cells during KSHV reactivation. Notably, knockdown of RUNX3 significantly promotes viral lytic replication as well as the gene transcription of KSHV. Consistent with this finding, overexpression of RUNX3 impairs viral lytic replication. Mechanistically, RUNX3 binds to the KSHV genome and limits viral replication through transcriptional repression, which is related to its DNA- and ATP-binding ability. However, KSHV has also evolved corresponding strategies to antagonize this inhibition by using the viral protein RTA to target RUNX3 for ubiquitination and proteasomal degradation. Altogether, our study suggests that RUNX3, a novel host-restriction factor of KSHV that represses the transcription of viral genes, may serve as a potential target to restrict KSHV transmission and disease development.IMPORTANCEThe reactivation of Kaposi's sarcoma-associated herpesvirus (KSHV) from latent infection to lytic replication is important for persistent viral infection and tumorigenicity. However, reactivation is a complex event, and the regulatory mechanisms of this process are not fully elucidated. Our study revealed that the host RUNX3 is upregulated by the NF-κB signaling pathway during KSHV reactivation, which can repress the transcription of KSHV genes. At the late stage of lytic replication, KSHV utilizes a mechanism involving RTA to degrade RUNX3, thus evading host inhibition. This finding helps elucidate the regulatory mechanism of the KSHV life cycle and may provide new clues for the development of therapeutic strategies for KSHV-associated diseases.


Assuntos
Subunidade alfa 3 de Fator de Ligação ao Core , Herpesvirus Humano 8 , Infecção Latente , Humanos , Linhagem Celular Tumoral , Regulação Viral da Expressão Gênica , Genoma Viral , Herpesvirus Humano 8/fisiologia , NF-kappa B/metabolismo , Ativação Viral , Latência Viral , Replicação Viral , Subunidade alfa 3 de Fator de Ligação ao Core/metabolismo
3.
Nanotechnology ; 32(7): 075201, 2021 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-33113523

RESUMO

Photodetectors based on high-performance, two-dimensional (2D) layered transition metal dichalcogenides (TMDCs) are limited by the synthesis of larger-area 2D TMDCs with high quality and optimized device structure. Herein, we report, for the first time, a uniform and stacked-layered MoSe2 film of high quality was deposited onto Si substrate by using the pulsed laser deposition technique, and then in situ constructed layered MoSe2/Si 2D-3D vertical heterojunction. The resultant heterojunction showed a wide near-infrared response up to 1550 nm, with both ultra-high detectivity up to 1.4 × 1014 Jones and a response speed approaching 120 ns at zero bias, which are much better than most previous 2D TMDC-based photodetectors and are comparable to that of commercial Si photodiodes. The high performance of the layered MoSe2/Si heterojunction can be attributed to be the high-quality stacked-layered MoSe2 film, the excellent rectifying behavior of the device and the n-n heterojunction structure. Moreover, the defect-enhanced near-infrared response was determined to be Se vacancies from the density functional theory (DFT) simulations. These results suggest great potential of the layered MoSe2/Si 2D-3D heterojunctions in the field of communication light detection. More importantly, the in situ grown heterojunctions are expected to boost the development of other 2D TMDCs heterojunction-based optoelectronic devices.

4.
Soft Matter ; 11(14): 2885-92, 2015 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-25727484

RESUMO

The concentration-dependent enthalpies of mixing for water/sodium bis(2-ethylhexyl)-sulfosuccinate (AOT)/n-alkane microemulsions with different water contents ω0 and chain lengths n of n-alkane were determined by isothermal titration microcalorimetry (ITC) and flow-mixing microcalorimetry at 298.15 K and used to calculate the interaction enthalpies (-ΔH(C)) between the droplets. It was found that -ΔH(C) increased with ω0, and changed from negative to positive at about ω0 = 10. The investigation of the dependence of -ΔH(C) on n revealed that the values of -ΔH(C) were negative and had a minimum for ω0 = 5; while they were positive and had a maximum for ω0 = 15. These phenomena were discussed based on the competition of the overlapping contribution of the surfactant tails between two neighbouring droplets and the penetration contribution of the solvent molecules into the surfactant tails. These results indicated the important role of entropy in the stability of the microemulsion systems.

5.
Soft Matter ; 10(40): 7977-84, 2014 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-25154518

RESUMO

In this paper, we investigated the dilution enthalpies of the droplets in water/AOT/oil microemulsions with oil being isooctane, decane, or cyclohexane by isothermal titration microcalorimetry (ITC). Combining with the results obtained from the study of the water/AOT/toluene system in our previous work, it was found that the enthalpy interactions between droplets for isooctane and decane systems were repulsive, while the enthalpy interactions were attractive for cyclohexane and toluene systems. The repulsive droplet interaction for the isooctane system was also confirmed by static light scattering. The solvents appear to play important roles in varying the droplet enthalpy interactions from positive to negative, and the entropy contribution seems to be dominant for the stability of these microemulsion droplet systems.

6.
Langmuir ; 27(20): 12280-3, 2011 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-21913718

RESUMO

A new experimental design for the measurement of the real heat of dilution of the microemulsion droplets by isothermal titration microcalorimetry (ITC) has been reported and used to study the interaction enthalpies of the droplets for the system of water/sodium bis(2-ethylhexyl)-sulfosuccinate (AOT)/toluene. The results are in good agreement with those determined from light-scattering experiments.


Assuntos
Emulsões , Termodinâmica , Varredura Diferencial de Calorimetria , Ácido Dioctil Sulfossuccínico/química , Emulsões/química , Tolueno/química , Água/química
7.
Adv Sci (Weinh) ; 8(16): e2101019, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34075724

RESUMO

Structural design of advanced cathodes is a promising strategy to suppress the shuttle effect for lithium-sulfur batteries (LSBs). In this work, the carbon cloth covered with CoS2 nanoparticles (CC-CoS2 ) is prepared to function as both three-dimensional (3D) current collector and physicochemical barrier to retard migration of soluble lithium polysulfides. On the one hand, the CC-CoS2 film works as a robust 3D current collector and host with high conductivity, high sulfur loading, and high capability of capturing polysulfides. On the other hand, the 3D porous CC-CoS2 film serves as a multifunctional interlayer that exhibits efficient physical blocking, strong chemisorption, and fast catalytic redox reaction kinetics toward soluble polysulfides. Consequently, the Al@S/AB@CC-CoS2 cell with a sulfur loading of 1.2 mg cm-2 exhibits a high rate capability (≈823 mAh g-1 at 4 C) and delivers excellent capacity retention (a decay of ≈0.021% per cycle for 1000 cycles at 4 C). Moreover, the sandwiched cathode of CC-CoS2 @S/AB@CC-CoS2 is designed for high sulfur loading LSBs. The CC-CoS2 @S/AB@CC-CoS2 cells with sulfur loadings of 4.2 and 6.1 mg cm-2 deliver high reversible capacities of 1106 and 885 mAh g-1 , respectively, after 100 cycles at 0.2 C. The outstanding electrochemical performance is attributed to the sandwiched structure with active catalytic component.

8.
Oncol Lett ; 17(1): 388-397, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30655779

RESUMO

Hepatocellular carcinoma (HCC) is a heterogeneous malignancy type with limited approaches for treatment. Additionally, inappropriate immune therapy indicates that the understanding the underlying mechanism of HCC is necessary. The aim of the present study was to investigate the influence of a novel circular RNA (circRNA), circRNA of AR-suppressed PABPC1 91 bp (CircARSP91), on immune surveillance induced by natural killer (NK) cells. An in vitro cell cytotoxicity assay was performed to determine the cytotoxicity of NK cells against HCC cells. A specific plasmid for circRNA overexpression was used to establish stable cell lines. Additionally, samples from patients with HCC were analyzed to determine the association between the present in vitro data and those of clinical settings. CircARSP91 could increase the susceptibility of HCC cells to NK cell cytotoxicity. Following screening multiple factors that could influence the activation of NK cells, it was determined that such a phenotype may be caused by upregulating UL16 binding protein 1 (ULBP1) expression in HCC cells at the mRNA and protein levels. Additionally, the data generated from patient samples significantly support a positive association between CircARSP91 and ULBP1. In conclusion, CircARSP91 could enhance innate immune surveillance by strengthening the cytotoxicity of NK cells, implying that circRNA may serve a role in tumor immunity.

9.
Zhonghua Wei Chang Wai Ke Za Zhi ; 17(12): 1216-9, 2014 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-25529957

RESUMO

OBJECTIVE: To explore a new procedure of laparoscopic dual anastomosis for mid-low rectal cancer to reduce postoperative complications. METHODS: Clinical data of 56 patients with mid-low rectal cancer undergoing laparoscopic rectal cancer resection(modified double-stapling technique, MDST, modification group) in the Department of General Surgery, the First Affiliated Hospital of Soochow University from February 2010 to June 2014 were compared with the data of 64 patients with mid-low rectal cancer (conventional double-stapling technique, DST, convention group) in the same period based on gender, age, tumor size, the distance from lower edge to the dentate line and tumor staging, etc. Patients in the modification group received operation as follows: (1) the rectum distal end was closed vertically instead of horizontally. (2) the anastomosis was conducted in an "end-corner" approach. (3) upper corner of the closed line in the distal end of rectum was removed. (4) the lower corner of closed line in the distal end of rectum was removed using vascular occlusion clamp method. (5) two T-shaped interchanges ("dangerous triangle") of stapled sutures formed after anastomosis were strengthened with absorbable suture. Patients in the convention group received laparoscopic dual anastomosis using conventional method: two corners and "dangerous triangles" were kept without any treatment. The clinical outcomes of two groups were analyzed retrospectively. RESULTS: The intraoperational blood loss, postoperative drainage volume, postoperative anastomotic stoma bleeding, bowel function return and hospital stay were not significantly different between the two groups (all P>0.05). As compared to the convention group, the modification group had longer operation time [(211 ± 91) min vs. (174 ± 57) min, P<0.05], lower incidence of postoperative anastomotic leakage [1.8%(1/56) vs. 12.5% (8/64), P=0.030], lower tenesmus rate [3.6% (2/56) vs. 14.1% (9/64), P<0.05], less postoperative stoma re-creation [0 vs. 9.4% (6/64), P<0.05]. CONCLUSION: Modified laparoscopic dual anastomosis for mid-low rectal cancer can significantly reduce the incidence of post-surgical complications such as anastomotic leakage.


Assuntos
Neoplasias Retais/cirurgia , Anastomose Cirúrgica , Fístula Anastomótica , Humanos , Laparoscopia , Estadiamento de Neoplasias , Duração da Cirurgia , Complicações Pós-Operatórias , Estudos Retrospectivos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA