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1.
Mol Med Rep ; 21(2): 918-926, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31974623

RESUMO

Isodicentric Y chromosomes are considered one of the most common structural abnormalities of the Y chromosome. Neocentric marker chromosomes, with neocentromeres, have drawn increasing attention in recent years. The present study reported an azoospermic male with a neocentric isochromosome Yp, neo(Yp), and an isodicentric Yq, idic(Yq). The karyotype was analyzed using G­banding, chromosome microarray analysis (CMA), and fluorescence in situ hybridization (FISH) with various detection probes, including sex­determining region on the Y chromosome (SRY) and Y centromeric, applied at the same time. G­banding initially revealed the karyotype 47,X,i(Y)(q10),+mar. CMA indicated the presence of an extra Y chromosome, seemingly equivalent to 47,XYY males. FISH delineated the existence of two centromeres on the idic(Yq). For the marker chromosome, two SRY signals were detected instead of the Y­specific centromere signal, and a visual centromere was observed. This indicated the possible existence of a neocentromere in the marker chromosome, located in the connected region in Yp11.2 band. Finally, the patient's karyotype was established as 47,X,idic(Y)(p11.2), neo(Y)(pter→Yp11.2::Yp11.2→pter). The findings suggested that both idic(Yq) and neo(Yp) could be the main causes of the patient's azoospermia, despite the fact that the partial disomy of Ypter to Yp11.2 did not lead to any major malformations. The present study not only improves the understanding of karyotype/phenotype relationships between neocentric marker Y chromosomes and male infertility, but also supports the hypothesis that the combined application of molecular cytogenetic analysis could aid in reliably confirming breakpoints, origins, and the constitution of the marker chromosomes.

2.
Fetal Pediatr Pathol ; 39(1): 51-61, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31215292

RESUMO

Introduction: Epithelioid sarcoma is a malignant mesenchymal tumor exhibiting epithelioid cytomorphology and epithelial phenotype. Its histogenesis is unknown, but its tumorigenesis may relate to inactivation of hSNF5/SMARCB1/INI1 tumor suppressor gene. This tumor typically affects young adults and older children, but it is uncommon in infants. Case Report: We describe a unique neoplasm in a 15-month-old infant presenting with a heel mass. The tumor was remarkable for retention of SMARCB1/INI1 expression. Conventional cytogenetic analysis revealed trisomy 2 and double minutes, and SNP array analysis confirmed the trisomy 2 and identified segmental amplification of chromosome 11 containing YAP1 and BIRC3; FISH testing proved that the double minutes consisted of BIRC3 and YAP1, potent oncogenes related to tumorigenesis of several types of tumors but not described in epithelioid sarcoma. Conclusion: Our findings expand the spectrum of cytogenetic alterations in this neoplasm, help in better understanding its tumorigenesis, and suggest potential therapeutic targets.

3.
Biosens Bioelectron ; 148: 111820, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31706174

RESUMO

Cell survival rate (CSR) is a very important parameter in biological and medical fields. Today, the routine method to determine this parameter is time-consuming; it also makes the labeled cells no longer useable for subsequent experiments. Here, we developed an on-chip label-free method for determining the CSR. For the method, a hypertonic stimulus was designed to create volume differences between living and dead cells, and then, the differences were characterized with measurements of impedance as the cells flowed through two electrodes. Based on the method, a microfluidic hypertonic stimulus-based impedance flow cytometry chip (HSIFC) was designed, and the localized function of the HSIFC was verified. Finally, the performance of the HSIFC was confirmed by measuring the different CSRs for the different types of cells. The results show that the HSIFC can accurately determine the CSR, and the accuracy is comparable to that of flow cytometry. This work paves the way for the label-free evaluation of CSR after various cell manipulations and treatments on the chip and promotes the versatility of lab-on-a-chip devices.

4.
Oncol Lett ; 18(6): 6725-6731, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31807181

RESUMO

Translocation (9;11)(p21.3;q23.3) is one of the most common lysine methyltransferase 2A (KMT2A)-rearrangements in de novo and therapy-related acute myeloid leukemia (AML). Numerous in vitro and in vivo studies have demonstrated that the KMT2A/MLLT3 super elongation complex subunit (MLLT3) fusion gene on the derivative chromosome 11 serves a crucial role in leukemogenesis. Trisomy 9 as a secondary chromosome change in patients with t(9;11) is relatively rare. The present study reported a unique case of AML with a chromosome 9 trisomy secondary to t(9;11)(p21.3;q23.3) through the cytogenetic analysis of leukemic blood and bone marrow. Further characterization with fluorescence in situ hybridization and array comparative genomic hybridization analysis revealed that this extra chromosome 9 was either a copy of normal chromosome 9 or a derivative chromosome 9. Conversely with the previously reported favorable outcome of AML patients with t(9;11)(p21.3;q23.3), in the present study, the cells with only translocation persisted, whereas the cells with an extra chromosome 9 disappeared following initial chemotherapy. With this unique case, the present study hypothesized that the extra chromosome 9 could serve a crucial role in AML disease progression and contribute to cellular sensitivity to chemotherapy.

5.
Biomed Res Int ; 2019: 9398275, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31828149

RESUMO

Small supernumerary marker chromosomes (sSMCs), equal in size or smaller than chromosome 20 of the same metaphase, can hardly be identified through traditional banding technique. They are usually associated with intelligent disability, growth retardation, and infertility, but the genotype-phenotype correlations are still complicated for their complex origins and constitutions. Herein, we identified a 26-year-old Chinese infertile male who carried a mosaic sSMC and was diagnosed as severe oligospermia. The G-banding analysis initially described his karyotype as mos 47, XY, +mar[32]/46, XY[18]. The chromosomal microarray analysis results showed a 25.5 Mb gain in Yp11.31q11.23 and a 0.15 Mb loss in Yq12. Two SRY signals were discovered in the "seemingly" normal chromosome Y in both cell lines using SRY probe: one normal SRY was located on the distal tip of the short arm of chromosome Y while the other SRY was located on the terminal of long arm in the same chromosome Y. The sSMC(Y) was finally identified as der(Y) (pter ⟶ q11.23) (SRY-). To our knowledge, the chromosomal Y anomalies, SRY gene translocated from der(Y) (pter ⟶ q11.23) to qter of normal chromosome Y, were not reported before. Our findings indicated that the mosaic presence of sSMC(Y) may be the main cause of severe oligospermia although no other apparent abnormalities were observed in the proband. Further research on association between sSMC(Y) and spermatogenesis impairment should be investigated. It is recommended measures of traditional and molecular cytogenetic analysis should be taken to determine the origins and constitutions of sSMC so as to offer more appropriate genetic counseling for the infertile sSMC carriers.

6.
Medicine (Baltimore) ; 98(49): e18258, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31804359

RESUMO

RATIONALE: Chromosomal duplications are associated with a series of genetic disorders. However, chromosome 5q duplications, especially pure 5q35.3 microduplications, have rarely been reported in the literature. Clinical phenotypes usually depend on the region of chromosome duplicated, its size, and loci. PATIENT CONCERNS: From 2011 to 2017, prenatal amniotic fluid samples were obtained from 6 pregnant women diagnosed with pure 5q35.3 microduplications following different prenatal indications at our center. We followed up the children of these pregnancies and determined their postnatal health conditions. DIAGNOSES: Cytogenetic studies delineated that all patients had normal karyotypes, except for patient 6 who had 46,XX,inv(9)(p11q13). Single-nucleotide polymorphism array results showed 177-269 kb duplications of 5q35.3 (chr5:178728830-178997692) in these cases. All shared similar localization of ADAMTS2. INTERVENTIONS: All pregnant women chose to continue the pregnancies. Follow-up analysis showed that the children presented normal physical and growth developments. OUTCOMES: We described six prenatal cases with similar 5q35.3 duplications involving part of the ADAMTS2 locus with no apparent postnatal phenotypic abnormalities. LESSONS: Our research revealed that partial microduplication of ADAMTS2 (chr5:178728830-178997692) might be benign and not correlate with disorders. And there might exist phenotypic diversities of 5q35.3 duplications.


Assuntos
Proteínas ADAMTS/genética , Duplicação Cromossômica , Diagnóstico Pré-Natal , Adulto , Feminino , Humanos , Recém-Nascido , Fenótipo , Polimorfismo de Nucleotídeo Único , Gravidez , Resultado da Gravidez
7.
J Clin Transl Hepatol ; 7(3): 249-257, 2019 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-31608217

RESUMO

Background and Aims: Data are limited on the use of pegylated-interferon alpha-2a (peg-IFNα) in Chinese patients with chronic hepatitis B virus (HBV) infection (CHB). We evaluated the effectiveness and safety of peg-IFNα in Chinese patients with hepatitis B envelope antigen-negative CHB in routine clinical practice. Methods: In this prospective, multicenter, observational, non-interventional cohort study, patients were assessed for up to 1 year after peg-IFNα treatment cessation. Treating physicians established the dosing and treatment duration according to Chinese clinical practice. Effectiveness of peg-IFNα treatment was measured by the percentage of: patients with HBV DNA <2000 IU/mL and loss of hepatitis B surface antigen (commonly known as HBsAg); HBV DNA level at end of treatment (EOT), and 6 months and 1 year posttreatment; and time course change in quantitative HBV DNA and HBsAg. Results: At EOT, 6 months posttreatment, and 1 year posttreatment, the percentage of patients with HBV DNA <2000 IU/mL was 90.0%, 81.8%, and 82.2%, and that of patients with HBsAg loss was 6.5%, 9.4%, and 9.5%, respectively. The HBV DNA level decreased from 5.61 log IU/mL at baseline to 2.48 log IU/mL at EOT and 2.67 log IU/mL at 1 year posttreatment. The HBsAg level decreased from 3.08 log IU/mL at baseline to 2.24 log IU/mL at EOT and 2.10 log IU/mL at 1 year posttreatment. The incidence of adverse events was 52.0%. Conclusions: Peg-IFNα has the potential to provide functional cure (HBsAg loss) for CHB and is well tolerated in hepatitis B envelope antigen-negative CHB patients in routine clinical practice in China. Clinical Trial Registration: ClinicalTrials.gov (NCT01730508).

8.
EMBO J ; 38(24): e101751, 2019 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-31571254

RESUMO

Repetitive DNA sequences are often associated with chromosomal rearrangements in cancers. Conventionally, single-strand annealing (SSA) is thought to mediate homology-directed repair of double-strand breaks (DSBs) between two repeats, causing repeat-mediated deletion (RMD). In this report, we demonstrate that break-induced replication (BIR) is used predominantly over SSA in mammalian cells for mediating RMD, especially when repeats are far apart. We show that SSA becomes inefficient in mammalian cells when the distance between the DSBs and the repeats is increased to the 1-2 kb range, while BIR-mediated RMD (BIR/RMD) can act over a long distance (e.g., ~ 100-200 kb) when the DSB is close to one repeat. Importantly, oncogene expression potentiates BIR/RMD but not SSA, and BIR/RMD is used more frequently at single-ended DSBs formed at collapsed replication forks than at double-ended DSBs. In contrast to short-range SSA, H2AX is required for long-range BIR/RMD, and sequence divergence strongly suppresses BIR/RMD in a manner partially dependent on MSH2. Our finding that BIR/RMD has a more important role than SSA in mammalian cells has a significant impact on the understanding of repeat-mediated rearrangements associated with oncogenesis.

9.
J Cell Mol Med ; 23(11): 7474-7489, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31565863

RESUMO

We aimed to identify key genes and pathways associated with different immune statuses of hepatitis B virus (HBV) infection. The gene expression and DNA methylation profiles were analysed in different immune statuses of HBV infection. Differentially expressed genes (DEGs) and differentially methylated genes (DMGs) were identified, followed by their functional and integrative analyses. The differential expression of IgG Fc receptors (FcγRs) in chronic HBV-infected patients and immune cells during different stages of HBV infection was investigated. Toll-like receptor (TLR) signalling pathway (including TLR6) and leucocyte transendothelial migration pathway (including integrin subunit beta 1) were enriched during acute infection. Key DEGs, such as FcγR Ib and FcγR Ia, and interferon-alpha inducible protein 27 showed correlation with alanine aminotransferase levels, and they were differentially expressed between acute and immune-tolerant phases and between immune-tolerant and immune-clearance phases. The integrative analysis of DNA methylation profile showed that lowly methylated and highly expressed genes, including cytotoxic T lymphocyte-associated protein 4 and mitogen-activated protein kinase 3 were enriched in T cell receptor signalling pathway during acute infection. Highly methylated and lowly expressed genes, such as Ras association domain family member 1 and cyclin-dependent kinase inhibitor 2A were identified in chronic infection. Furthermore, differentially expressed FcγR Ia, FcγR IIa and FcγR IIb, CD3- CD56+ CD16+ natural killer cells and CD14high CD16+ monocytes were identified between immune-tolerant and immune-clearance phases by experimental validation. The above genes and pathways may be used to distinguish different immune statuses of HBV infection.

10.
Medicine (Baltimore) ; 98(38): e17200, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31567968

RESUMO

The universal two-child policy has now been fully implemented in China. This change requires adaptations to maternal care and childcare systems, but the features of prenatal diagnosis before and after implementation of the policy have not been reported.We conducted a retrospective study of 6736 prenatal cytogenetic diagnoses performed on amniotic fluid cells over a 4-year period, including 2 years before and after implementation of the second child policy. Amniotic fluid cells collected through amniocentesis were cultured, harvested, and stained for chromosome analysis using standard laboratory protocols.The study included 3222 pregnant women referred before implementation of the policy, which we used as a control group, and 3514 pregnant women referred after policy implementation as an investigational study group. There were significantly fewer pregnant women aged <25 years in the investigational group than in the control group (P < .001). There were no significant between-group differences for other pregnant women aged >31 years and 27-28 years old (P > .05). A total of 358 cases with chromosomal abnormalities were diagnosed, including 129 (4%, 129/3222) in the control group which was significantly lower than the 229 (6.5%, 229/3514) in the study group (P < .001). In particular, significantly more trisomy 21 cases were observed in the study group than in the control group (120 vs 59). More pregnant women underwent non-invasive prenatal testing (NIPT) in the study group (46%) than in the control group (20%). In the study group, the average age of pregnant women who underwent NIPT was significantly higher than that of women who did not receive NIPT (P < .05). However, there were no significant between-group differences for the control group (P > .05).The number of cases with chromosomal abnormalities increased in northeastern China in the 2 years after implementation of the two-child policy. The number of pregnant women of advanced maternal age did not increase significantly, perhaps because of the widespread application of NIPT. However, the number of fetuses with Down syndrome increased significantly, suggesting that prenatal screening and diagnosis should be strengthened.


Assuntos
Controle da População , Diagnóstico Pré-Natal/estatística & dados numéricos , Política Pública , Adulto , Fatores Etários , Amniocentese/estatística & dados numéricos , China , Aberrações Cromossômicas , Feminino , Humanos , Controle da População/estatística & dados numéricos , Gravidez , Estudos Retrospectivos , Adulto Jovem
11.
Prenat Diagn ; 39(12): 1120-1126, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31461790

RESUMO

INTRODUCTION: Pure duplication of chromosome 18p is rare, with clinical phenotypes ranging from normal or slight abnormalities to various degrees of mental retardation. It remains difficult to establish a clear genotype-phenotype correlation. METHODS: Chromosomal karyotyping analysis was performed on cultured amniotic fluid cells from three cases. Single nucleotide polymorphism (SNP) array analysis was carried out using the Illumina Human CytoSNP-12 BeadChip. We also carried out a review of the literature regarding 18p11 microduplication. RESULTS: G-banding analysis showed that the three cases had normal karyotypes. SNP array results showed 0.48- to 1.6-Mb microduplications of 18p11.31-p11.22 (chr18: 6995739-8713088) in these cases, encompassing different degrees of LAMA1 duplication. Follow-up analysis showed that the parents of both cases 1 and 2 chose termination of pregnancy. Case 3 presented with normal growth and physical development. Currently, there is not enough evidence supporting the pathogenicity of LAMA1 triplosensitivity. CONCLUSION: We described three prenatal cases with 18p11.31-p11.22 microduplications involving part of the LAMA1 locus. There might be phenotypic diversity associated with 18p11.31-p11.22 microduplications. To avoid unnecessary abortions for pregnancies such as these, comprehensive genetic counseling should be offered.

12.
iScience ; 16: 63-78, 2019 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-31153042

RESUMO

The structure-specific endonuclease ERCC1/XPF plays an important role in nucleotide excision repair and interstrand cross-link repair. In this study, we identified new functions of ERCC1/XPF in DNA double-strand break (DSB) repair. We found that the conserved function of ERCC1/XPF to remove non-homologous sequences at DSBs is a rate-limiting step for homologous recombination in mammalian cells, and more importantly, we uncovered an indispensable role of ERCC1/XPF in repair of DSBs containing DNA secondary structures, including the structure-prone AT-rich DNA sequences derived from common fragile sites and G-quadruplexes (G4s). We also demonstrated a synthetic lethal interaction of XPF with DNA translocase FANCM that is involved in removing DNA secondary structures. Furthermore, inactivation of XPF sensitizes FANCM-deficient cells to G4-interacting compounds. These results suggest an important function of ERCC1/XPF in protecting DNA secondary structures and provide a rationale for targeted treatment of FANCM-deficient tumors through inhibition of XPF.

13.
BMC Cancer ; 19(1): 106, 2019 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-30691436

RESUMO

BACKGROUND: MYCN amplification directly correlates with the clinical course of neuroblastoma and poor patient survival, and serves as the most critical negative prognostic marker. Although fluorescence in situ hybridization (FISH) remains the gold standard for clinical diagnosis of MYCN status in neuroblastoma, its limitations warrant the identification of rapid, reliable, less technically challenging, and inexpensive alternate approaches. METHODS: In the present study, we examined the concordance of droplet digital PCR (ddPCR, in combination with immunohistochemistry, IHC) with FISH for MYCN detection in a panel of formalin-fixed paraffin-embedded (FFPE) human neuroblastoma samples. RESULTS: In 112 neuroblastoma cases, ddPCR analysis demonstrated a 96-100% concordance with FISH. Consistently, IHC grading revealed 92-100% concordance with FISH. Comparing ddPCR with IHC, we observed a concordance of 95-98%. CONCLUSIONS: The results demonstrate that MYCN amplification status in NB cases can be assessed with ddPCR, and suggest that ddPCR could be a technically less challenging method of detecting MYCN status in FFPE specimens. More importantly, these findings illustrate the concordance between FISH and ddPCR in the detection of MYCN status. Together, the results suggest that rapid, less technically demanding, and inexpensive ddPCR in conjunction with IHC could serve as an alternate approach to detect MYCN status in NB cases, with near-identical sensitivity to that of FISH.


Assuntos
Proteína Proto-Oncogênica N-Myc/genética , Neuroblastoma/diagnóstico , Reação em Cadeia da Polimerase , Biomarcadores Tumorais/genética , Formaldeído , Amplificação de Genes , Humanos , Imuno-Histoquímica , Hibridização in Situ Fluorescente , Neuroblastoma/genética , Neuroblastoma/patologia , Inclusão em Parafina , Sensibilidade e Especificidade
14.
J Biol Chem ; 294(11): 3909-3919, 2019 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-30655289

RESUMO

DNA polymerase θ (POLQ) plays an important role in alternative nonhomologous end joining or microhomology-mediated end joining (alt-NHEJ/MMEJ). Here, we show that POLQ is not only required for MMEJ to repair DNA double-strand breaks (DSBs) generated by endonucleases such as I-SceI or Cas9, but is also needed for repair of DSBs derived from DNA nicks generated by Cas9 nickase. Consistently, we found that POLQ deficiency leads to sensitivity to topoisomerase inhibitors that cause DNA single-strand break (SSB) accumulation at replication forks and to ATR inhibitors that induce replication fork collapse. These studies support the function of POLQ in coping with replication stress and repairing DSBs upon fork collapse. POLQ overexpression is present in many cancer types and is associated with poor prognosis, including breast cancer regardless of BRCA1 status. We provide proof-of-concept evidence to support a novel cancer treatment strategy that combines POLQ inhibition with administration of topoisomerase or ATR inhibitors, which induces replication stress and fork collapse. Given the prevalence of POLQ overexpression in tumors, such strategy may have a significant impact on developing targeted cancer treatment.


Assuntos
Quebras de DNA de Cadeia Dupla , Reparo do DNA , Replicação do DNA , DNA Polimerase Dirigida por DNA/metabolismo , Camptotecina/farmacologia , Células Cultivadas , Quebras de DNA de Cadeia Dupla/efeitos dos fármacos , Replicação do DNA/efeitos dos fármacos , DNA Polimerase Dirigida por DNA/deficiência , DNA Polimerase Dirigida por DNA/genética , Relação Dose-Resposta a Droga , Humanos , Isoxazóis/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Pirazinas/farmacologia , Relação Estrutura-Atividade , Inibidores da Topoisomerase/farmacologia
15.
Comput Methods Biomech Biomed Engin ; 22(2): 217-228, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30596516

RESUMO

Finite element analysis (FEA) can be implemented along with Agent-based model (ABM) to investigate the biomechanical and mechanobiological mechanisms of pathophysiological processes. However, traditional ABM-FEA approaches are often partially coupled and lack the feedback responses from biological analysis. To overcome this problem, a fully coupled ABM-FEA framework is developed in this paper by linking the macro-scale and cell-scale modules bi-directionally. Numerical studies of the in-stent restenosis process are conducted using the proposed approach and comparisons are made between the two types of frameworks. A reduction in lumen loss rate, which is possibly caused by the time-varying stresses, is observed in the fully coupled simulations. The re-endothelialisation process is also simulated under different frameworks and the simulation results show strong inhibition of endothelial cells to vascular restenosis. The proposed method is proved to be effective to explain the biomechanical-mechanobiological coupling characteristics of the restenosis problem and can be utilized for stent design and optimization.


Assuntos
Simulação por Computador , Reestenose Coronária/fisiopatologia , Stents , Algoritmos , Constrição Patológica , Células Endoteliais/patologia , Análise de Elementos Finitos , Humanos , Modelos Biológicos , Músculo Liso Vascular/patologia , Miócitos de Músculo Liso/patologia
16.
Comput Biol Med ; 104: 205-214, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30529572

RESUMO

Self-expanding Nitinol stents are increasingly used to treat femoropopliteal artery (FPA) occlusions, but the risk of stent fatigue failure exists due to complex artery deformation during daily activities. Finite element analysis (FEA) has been widely applied to study the stent fatigue behaviours, but physiological deformation and atherosclerotic plaque were not considered simultaneously in previous studies. In this work, to show the necessity and feasibility of considering both factors in evaluation of the stent fatigue behaviours, a comprehensive FEA framework considering both factors is established, and an easy loading method for the complex boundary condition is proposed. Four comparative simulations are successfully conducted, and the stent fatigue behaviours are analysed based on the distributions and maximum values of the self-defined mean and alternating strains. Results show that both the physiological deformation and atherosclerotic plaque significantly contribute to the stent fatigue life. The case with the complex boundary condition and atherosclerotic plaque is the most critical of the four cases, and the minimum safety factor is 0.62. In conclusion, it is necessary to consider both physiological deformation and atherosclerotic plaque in the evaluation of stent fatigue behaviours, and ignoring any of them would lead to overestimation of the stent fatigue life. The work in this paper offers a solid foundation for accurate evaluation of the stent fatigue lifetime in patient-specific surgery plans via FEA.

17.
J Med Virol ; 91(1): 81-92, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30118556

RESUMO

We aimed to study the aberrant DNA methylation profile associated with hepatitis B virus (HBV) infection and, to identify key genes and pathways associated with the HBV infection stage. A total of 54 antiviral treatment-naïve HBV-infected patients and six healthy controls were included. Genome-wide methylated DNA immunoprecipitation analysis was performed, as previously described, after which the chip data were preprocessed. Subsequently, Cytoscape software was used for the construction of a protein-protein interaction network, and a database for annotation, visualization, and integrated discovery software was used to conduct functional enrichment analysis. A total of 711 794 CpGs were obtained after data quality control, among which 152 780, 113 814, 90 747, and 175 868 CpGs showed differential methylation in acute hepatitis B (AHB) vs control, total-C vs control, CH1 vs CA1, and AHB vs total-C, respectively. Furthermore, RIPK3, PRDM10, JUN, and SNAI1 were at the center of the four associated networks, respectively. Differential methylated genes differentially methylated in these four comparisons were significantly enriched with olfactory transduction; positive regulation of transport; negative regulation of protein amino acid phosphorylation (eg, JUN), phosphorylation, phosphorus metabolic process, and phosphate metabolic process; and programmed cell death, respectively. RIPK3, PRDM10, JUN, and SNAI1 as well as olfactory transduction, positive regulation of transport, negative regulation of phosphorylation, and programmed cell death are important for the transformation associated with HBV infection stage. Moreover, JUN may be involved in HBV infection, mainly via the negative regulation of amino acid phosphorylation.


Assuntos
Metilação de DNA , Epigênese Genética , Hepatite B/patologia , Adulto , Imunoprecipitação da Cromatina , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Anotação de Sequência Molecular , Adulto Jovem
18.
PLoS Genet ; 14(11): e1007816, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30496191

RESUMO

Genome instability often arises at common fragile sites (CFSs) leading to cancer-associated chromosomal rearrangements. However, the underlying mechanisms of how CFS protection is achieved is not well understood. We demonstrate that BLM plays an important role in the maintenance of genome stability of structure-forming AT-rich sequences derived from CFSs (CFS-AT). BLM deficiency leads to increased DSB formation and hyper mitotic recombination at CFS-AT and induces instability of the plasmids containing CFS-AT. We further showed that BLM is required for suppression of CFS breakage upon oncogene expression. Both helicase activity and ATR-mediated phosphorylation of BLM are important for preventing genetic instability at CFS-AT sequences. Furthermore, the role of BLM in protecting CFS-AT is not epistatic to that of FANCM, a translocase that is involved in preserving CFS stability. Loss of BLM helicase activity leads to drastic decrease of cell viability in FANCM deficient cells. We propose that BLM and FANCM utilize different mechanisms to remove DNA secondary structures forming at CFS-AT on replication forks, thereby preventing DSB formation and maintaining CFS stability.


Assuntos
Sítios Frágeis do Cromossomo , DNA/genética , DNA/metabolismo , Instabilidade Genômica , RecQ Helicases/metabolismo , Sequência Rica em At , Proteínas Mutadas de Ataxia Telangiectasia/metabolismo , DNA/química , Quebras de DNA de Cadeia Dupla , DNA Helicases/metabolismo , Replicação do DNA , Expressão Gênica , Humanos , Mitose , Conformação de Ácido Nucleico , Oncogenes , Fosforilação , RecQ Helicases/genética , Recombinação Genética
19.
Materials (Basel) ; 11(10)2018 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-30326553

RESUMO

Ti3C2Tx MXene, a new 2D nanosheet material, is expected to be an attractive reinforcement of metal matrix composites because its surfaces are terminated with Ti and/or functional groups of ⁻OH, ⁻O, and ⁻F which improve its wettability with metals. Thus, new Ti3C2Tx/Al composites with strong interfaces and novel properties are desired. To prepare such composites, the chemical stability of Ti3C2Tx with Al at high temperatures should be investigated. This work first reports on the chemical stability of Ti3C2Tx MXene with Al in the temperature range 500⁻700 °C. Ti3C2Tx is thermally stable with Al at temperatures below 700 °C, but it reacts with Al to form Al3Ti and TiC at temperatures above 700 °C. The chemical stability and microstructure of the Ti3C2Tx/Al samples were investigated by differential scanning calorimeter, X-ray diffraction analysis, scanning electron microscopy, and transmission electron microscopy.

20.
JCI Insight ; 3(14)2018 07 26.
Artigo em Inglês | MEDLINE | ID: mdl-30046013

RESUMO

Site-1 protease (S1P), encoded by MBTPS1, is a serine protease in the Golgi. S1P regulates lipogenesis, endoplasmic reticulum (ER) function, and lysosome biogenesis in mice and in cultured cells. However, how S1P differentially regulates these diverse functions in humans has been unclear. In addition, no human disease with S1P deficiency has been identified. Here, we report a pediatric patient with an amorphic and a severely hypomorphic mutation in MBTPS1. The unique combination of these mutations results in a frequency of functional MBTPS1 transcripts of approximately 1%, a finding that is associated with skeletal dysplasia and elevated blood lysosomal enzymes. We found that the residually expressed S1P is sufficient for lipid homeostasis but not for ER and lysosomal functions, especially in chondrocytes. The defective S1P function specifically impairs activation of the ER stress transducer BBF2H7, leading to ER retention of collagen in chondrocytes. S1P deficiency also causes abnormal secretion of lysosomal enzymes due to partial impairment of mannose-6-phosphate-dependent delivery to lysosomes. Collectively, these abnormalities lead to apoptosis of chondrocytes and lysosomal enzyme-mediated degradation of the bone matrix. Correction of an MBTPS1 variant or reduction of ER stress mitigated collagen-trafficking defects. These results define a new congenital human skeletal disorder and, more importantly, reveal that S1P is particularly required for skeletal development in humans. Our findings may also lead to new therapies for other genetic skeletal diseases, as ER dysfunction is common in these disorders.


Assuntos
Doenças do Desenvolvimento Ósseo/genética , Doenças do Desenvolvimento Ósseo/metabolismo , Pró-Proteína Convertases/genética , Pró-Proteína Convertases/metabolismo , Transporte Proteico , Serina Endopeptidases/genética , Serina Endopeptidases/metabolismo , Apoptose , Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Doenças do Desenvolvimento Ósseo/fisiopatologia , Técnicas de Cultura de Células , Pré-Escolar , Condrócitos/metabolismo , Colágeno/metabolismo , Retículo Endoplasmático/metabolismo , Feminino , Técnicas de Silenciamento de Genes , Doenças Genéticas Inatas , Complexo de Golgi/metabolismo , Homeostase , Humanos , Lipogênese , Lisossomos/metabolismo , Manosefosfatos , Mutação
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