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1.
Oncol Res ; 32(4): 643-658, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38560570

RESUMO

The platinum-based chemotherapy is one of the most frequently used treatment protocols for lung adenocarcinoma (LUAD), and chemoresistance, however, usually results in treatment failure and limits its application in the clinic. It has been shown that microRNAs (miRNAs) play a significant role in tumor chemoresistance. In this study, miR-125b was identified as a specific cisplatin (DDP)-resistant gene in LUAD, as indicated by the bioinformatics analysis and the real-time quantitative PCR assay. The decreased serum level of miR-125b in LUAD patients was correlated with the poor treatment response rate and short survival time. MiR-125b decreased the A549/DDP proliferation, and the multiple drug resistance- and autophagy-related protein expression levels, which were all reversed by the inhibition of miR-125b. In addition, xenografts of human tumors in nude mice were suppressed by miR-125b, demonstrating that through autophagy regulation, miR-125b could reverse the DDP resistance in LUAD cells, both in vitro and in vivo. Further mechanistic studies indicated that miR-125b directly repressed the expression levels of RORA and its downstream BNIP3L, which in turn inhibited autophagy and reversed chemoresistance. Based on these findings, miR-125b in combination with DDP might be an effective treatment option to overcome DDP resistance in LUAD.


Assuntos
Adenocarcinoma de Pulmão , Neoplasias Pulmonares , MicroRNAs , Proteínas Supressoras de Tumor , Animais , Camundongos , Humanos , Cisplatino/farmacologia , Cisplatino/uso terapêutico , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Camundongos Nus , Resistencia a Medicamentos Antineoplásicos/genética , Linhagem Celular Tumoral , Apoptose/genética , Adenocarcinoma de Pulmão/tratamento farmacológico , Adenocarcinoma de Pulmão/genética , MicroRNAs/genética , MicroRNAs/metabolismo , Autofagia/genética , Regulação Neoplásica da Expressão Gênica , Membro 1 do Grupo F da Subfamília 1 de Receptores Nucleares/genética , Membro 1 do Grupo F da Subfamília 1 de Receptores Nucleares/metabolismo , Membro 1 do Grupo F da Subfamília 1 de Receptores Nucleares/farmacologia , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Proteínas Proto-Oncogênicas/genética
2.
BMC Bioinformatics ; 25(1): 142, 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38566005

RESUMO

BACKGROUND: The rapid advancement of new genomic sequencing technology has enabled the development of multi-omic single-cell sequencing assays. These assays profile multiple modalities in the same cell and can often yield new insights not revealed with a single modality. For example, Cellular Indexing of Transcriptomes and Epitopes by Sequencing (CITE-Seq) simultaneously profiles the RNA transcriptome and the surface protein expression. The surface protein markers in CITE-Seq can be used to identify cell populations similar to the iterative filtration process in flow cytometry, also called "gating", and is an essential step for downstream analyses and data interpretation. While several packages allow users to interactively gate cells, they often do not process multi-omic sequencing datasets and may require writing redundant code to specify gate boundaries. To streamline the gating process, we developed CITEViz which allows users to interactively gate cells in Seurat-processed CITE-Seq data. CITEViz can also visualize basic quality control (QC) metrics allowing for a rapid and holistic evaluation of CITE-Seq data. RESULTS: We applied CITEViz to a peripheral blood mononuclear cell CITE-Seq dataset and gated for several major blood cell populations (CD14 monocytes, CD4 T cells, CD8 T cells, NK cells, B cells, and platelets) using canonical surface protein markers. The visualization features of CITEViz were used to investigate cellular heterogeneity in CD14 and CD16-expressing monocytes and to detect differential numbers of detected antibodies per patient donor. These results highlight the utility of CITEViz to enable the robust classification of single cell populations. CONCLUSIONS: CITEViz is an R-Shiny app that standardizes the gating workflow in CITE-Seq data for efficient classification of cell populations. Its secondary function is to generate basic feature plots and QC figures specific to multi-omic data. The user interface and internal workflow of CITEViz uniquely work together to produce an organized workflow and sensible data structures for easy data retrieval. This package leverages the strengths of biologists and computational scientists to assess and analyze multi-omic single-cell datasets. In conclusion, CITEViz streamlines the flow cytometry gating workflow in CITE-Seq data to help facilitate novel hypothesis generation.


Assuntos
Leucócitos Mononucleares , Software , Humanos , Análise de Sequência de RNA/métodos , Fluxo de Trabalho , Citometria de Fluxo , Proteínas de Membrana , Análise de Célula Única/métodos , Perfilação da Expressão Gênica/métodos
3.
Cancer Discov ; 14(4): 639-642, 2024 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-38571413

RESUMO

SUMMARY: Cell surface proteins represent ideal therapeutic targets because of their accessibility to antibodies, T cell-directed therapies, and radiotherapies, but there are only 25 therapeutically relevant cell surface targets for which cancer therapies are approved in the United States or European Union. This commentary calls for intensified research into mapping the universe of cell surface proteins - the cell surfaceome - in order to accelerate cancer drug development.


Assuntos
Proteínas de Membrana , Neoplasias , Humanos , Proteínas de Membrana/metabolismo , Neoplasias/tratamento farmacológico
4.
J Med Virol ; 96(4): e29510, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38573018

RESUMO

Hepatitis B virus (HBV) infection poses a significant burden on global public health. Unfortunately, current treatments cannot fully alleviate this burden as they have limited effect on the transcriptional activity of the tenacious covalently closed circular DNA (cccDNA) responsible for viral persistence. Consequently, the HBV life cycle should be further investigated to develop new anti-HBV pharmaceutical targets. Our previous study discovered that the host gene TMEM203 hinders HBV replication by participating in calcium ion regulation. The involvement of intracellular calcium in HBV replication has also been confirmed. In this study, we found that transient receptor potential vanilloid 4 (TRPV4) notably enhances HBV reproduction by investigating the effects of several calcium ion-related molecules on HBV replication. The in-depth study showed that TRPV4 promotes hepatitis B core/capsid protein (HBc) protein stability through the ubiquitination pathway and then promotes the nucleocapsid assembly. HBc binds to cccDNA and reduces the nucleosome spacing of the cccDNA-histones complex, which may regulate HBV transcription by altering the nucleosome arrangement of the HBV genome. Moreover, our results showed that TRPV4 promotes cccDNA-dependent transcription by accelerating the methylation modification of H3K4. In conclusion, TRPV4 could interact with HBV core protein and regulate HBV during transcription and replication. These data suggest that TRPV4 exerts multifaceted HBV-related synergistic factors and may serve as a therapeutic target for CHB.


Assuntos
Antineoplásicos , Hepatite B , Humanos , Ubiquitina , Capsídeo , Proteínas do Capsídeo , Vírus da Hepatite B/genética , Canais de Cátion TRPV/genética , Cálcio , Nucleossomos , Metilação , Proteínas de Membrana
5.
Front Cell Infect Microbiol ; 14: 1380976, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38596648

RESUMO

Introduction: The hemin acquisition system is composed of an outer membrane TonB-dependent transporter that internalizes hemin into the periplasm, periplasmic hemin-binding proteins to shuttle hemin, an inner membrane transporter that transports hemin into the cytoplasm, and cytoplasmic heme oxygenase to release iron. Fur and HemP are two known regulators involved in the regulation of hemin acquisition. The hemin acquisition system of Stenotrophomonas maltophilia is poorly understood, with the exception of HemA as a TonB-dependent transporter for hemin uptake. Methods: Putative candidates responsible for hemin acquisition were selected via a homolog search and a whole-genome survey of S. maltophilia. Operon verification was performed by reverse transcription-polymerase chain reaction. The involvement of candidate genes in hemin acquisition was assessed using an in-frame deletion mutant construct and iron utilization assays. The transcript levels of candidate genes were determined using quantitative polymerase chain reaction. Results: Smlt3896-hemU-exbB2-exbD2-tonB2 and tonB1-exbB1-exbD1a-exbD1b operons were selected as candidates for hemin acquisition. Compared with the parental strain, hemU and tonB1 mutants displayed a defect in their ability to use hemin as the sole iron source for growth. However, hemin utilization by the Smlt3896 and tonB2 mutants was comparable to that of the parental strain. HemA expression was repressed by Fur in iron-replete conditions and derepressed in iron-depleted conditions. HemP negatively regulated hemA expression. Like hemA, hemU was repressed by Fur in iron-replete conditions; however, hemU was moderately derepressed in response to iron-depleted stress and fully derepressed when hemin was present. Unlike hemA and hemU, the TonB1-exbB1-exbD1a-exbD1b operon was constitutively expressed, regardless of the iron level or the presence of hemin, and Fur and HemP had no influence on its expression. Conclusion: HemA, HemU, and TonB1 contribute to hemin acquisition in S. maltophilia. Fur represses the expression of hemA and hemU in iron-replete conditions. HemA expression is regulated by low iron levels, and HemP acts as a negative regulator of this regulatory circuit. HemU expression is regulated by low iron and hemin levels in a hemP-dependent manner.


Assuntos
Hemina , Stenotrophomonas maltophilia , Stenotrophomonas maltophilia/genética , Stenotrophomonas maltophilia/metabolismo , Proteínas de Bactérias/metabolismo , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Ferro/metabolismo
6.
Appl Microbiol Biotechnol ; 108(1): 290, 2024 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-38587616

RESUMO

For the development of a competitive ELISA (cELISA) to detect serum antibodies against the Mycoplasma mycoides subsp. Mycoides (Mmm) (strain PG1), the causative agent of contagious bovine pleuropneumonia (CBPP), all the proteins of this pathogen were analyzed. Then, a specific extracellular region of a transmembrane protein with the potential for diagnosis was identified. After that, a monoclonal antibody (Mab) named 3A8 was obtained using this extracellular region as an immunogen. Finally, a cELISA was established with the extracellular domain of this transmembrane protein as the coating antigen, Mab 3A8 as the competitive antibody, and HRP-labeled goat anti-mouse IgG as the enzyme-labeled antibody. This established method was used to detect the antibody dynamic regularity of goats which are artificially immunized Mmm and was also compared with a commercial ELISA kit. Further, the sera of 1011 different cattle from border provinces of China were monitored using a candidate Mab 3A8 cELISA. The detection results of known background sera used in this study indicate that a candidate diagnostic marker was successfully identified by analyzing all the coding proteins of Mmm in this research, and the cELISA established based on the Mab 3A8 against this protein can detect CBPP-positive serum with specificity and has no cross-reaction with other related epidemic disease-positive sera. In addition, we tested the sera collected from the border areas of China using the established ELISA, and no positive sample was detected. The research protocol of the CBPP cELISA established in this study is different from the traditional method, which can greatly reduce the investment of manpower and capital and save development time. We believe that this study's protocol could serve as a reference for the development of detection methods for mycoplasma and other complex pathogens. KEY POINTS: • A Mmm-specific diagnostic marker was obtained based on protein characteristics. • A cELISA was established for CBPP serum antibody detection. • The serological investigation was conducted for CBPP in the border areas of China.


Assuntos
Anticorpos Monoclonais , Pleuropneumonia , Animais , Bovinos , Proteínas de Membrana , China , Ensaio de Imunoadsorção Enzimática , Cabras
7.
AIDS ; 38(6): 779-789, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38578957

RESUMO

OBJECTIVE: This study aims to investigate the functions and mechanistic pathways of Astrocyte Elevated Gene-1 (AEG-1) in the disruption of the blood-retinal barrier (BRB) caused by the HIV-1 envelope glycoprotein gp120. DESIGN: We utilized ARPE-19 cells challenged with gp120 as our model system. METHODS: Several analytical techniques were employed to decipher the intricate interactions at play. These included PCR, Western blot, and immunofluorescence assays for the molecular characterization, and transendothelial electrical resistance (TEER) measurements to evaluate barrier integrity. RESULTS: We observed that AEG-1 expression was elevated, whereas the expression levels of tight junction proteins ZO-1, Occludin, and Claudin5 were downregulated in gp120-challenged cells. TEER measurements corroborated these findings, indicating barrier dysfunction. Additional mechanistic studies revealed that the activation of NFκB and MMP2/9 pathways mediated the AEG-1-induced barrier destabilization. Through the use of lentiviral vectors, we engineered cell lines with modulated AEG-1 expression levels. Silencing AEG-1 alleviated gp120-induced downregulation of tight junction proteins and barrier impairment while concurrently inhibiting the NFκB and MMP2/9 pathways. Conversely, overexpression of AEG-1 exacerbated these pathological changes, further compromising the integrity of the BRB. CONCLUSION: Gp120 upregulates the expression of AEG-1 and activates the NFκB and MMP2/9 pathways. This in turn leads to the downregulation of tight junction proteins, resulting in the disruption of barrier function.


Assuntos
Barreira Hematorretiniana , Proteína gp120 do Envelope de HIV , Infecções por HIV , HIV-1 , Proteínas de Membrana , Proteínas de Ligação a RNA , Humanos , Barreira Hematorretiniana/metabolismo , Infecções por HIV/metabolismo , HIV-1/metabolismo , Metaloproteinase 2 da Matriz/metabolismo , Proteínas de Junções Íntimas/metabolismo , Proteína gp120 do Envelope de HIV/metabolismo , Proteínas de Membrana/metabolismo , Proteínas de Ligação a RNA/metabolismo
8.
Sci Immunol ; 9(94): eadk0092, 2024 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-38579014

RESUMO

The transition from immunoglobulin M (IgM) to affinity-matured IgG antibodies is vital for effective humoral immunity. This is facilitated by germinal centers (GCs) through affinity maturation and preferential maintenance of IgG+ B cells over IgM+ B cells. However, it is not known whether the positive selection of the different Ig isotypes within GCs is dependent on specific transcriptional mechanisms. Here, we explored IgG1+ GC B cell transcription factor dependency using a CRISPR-Cas9 screen and conditional mouse genetics. We found that MIZ1 was specifically required for IgG1+ GC B cell survival during positive selection, whereas IgM+ GC B cells were largely independent. Mechanistically, MIZ1 induced TMBIM4, an ancestral anti-apoptotic protein that regulated inositol trisphosphate receptor (IP3R)-mediated calcium (Ca2+) mobilization downstream of B cell receptor (BCR) signaling in IgG1+ B cells. The MIZ1-TMBIM4 axis prevented mitochondrial dysfunction-induced IgG1+ GC cell death caused by excessive Ca2+ accumulation. This study uncovers a unique Ig isotype-specific dependency on a hitherto unidentified mechanism in GC-positive selection.


Assuntos
Linfócitos B , Imunoglobulina G , Proteínas de Membrana , Animais , Camundongos , Centro Germinativo , Imunoglobulina G/metabolismo , Imunoglobulina M/metabolismo , Transdução de Sinais , Proteínas de Membrana/metabolismo
9.
Ren Fail ; 46(1): 2332492, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38584135

RESUMO

Acute kidney injury (AKI) is associated with a high mortality rate. Pathologically, renal ischemia/reperfusion injury (RIRI) is one of the primary causes of AKI, and hypoxia-inducible factor (HIF)-1α may play a defensive role in RIRI. This study assessed the role of hypoxia-inducible factor 1α (HIF-1α)-mediated mitophagy in protection against RIRI in vitro and in vivo. The human tubular cell line HK-2 was used to assess hypoxia/reoxygenation (H/R)-induced mitophagy through different in vitro assays, including western blotting, immunofluorescence staining, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL), and reactive oxygen species (ROS) measurement. Additionally, a rat RIRI model was established for evaluation by renal histopathology, renal Doppler ultrasound, and transmission electron microscopy to confirm the in vitro data. The selective HIF-1α inhibitor LW6 reduced H/R-induced mitophagy but increased H/R-induced apoptosis and ROS production. Moreover, H/R treatment enhanced expression of the FUN14 domain-containing 1 (FUNDC1) protein. Additionally, FUNDC1 overexpression reversed the effects of LW6 on the altered expression of light chain 3 (LC3) BII and voltage-dependent anion channels as well as blocked the effects of HIF-1α inhibition in cells. Pretreatment of the rat RIRI model with roxadustat, a novel oral HIF-1α inhibitor, led to decreased renal injury and apoptosis in vivo. In conclusion, the HIF-1α/FUNDC1 signaling pathway mediates H/R-promoted renal tubular cell mitophagy, whereas inhibition of this signaling pathway protects cells from mitophagy, thus aggravating apoptosis, and ROS production. Accordingly, roxadustat may protect against RIRI-related AKI.


Assuntos
Injúria Renal Aguda , Traumatismo por Reperfusão , Animais , Humanos , Ratos , Injúria Renal Aguda/etiologia , Injúria Renal Aguda/prevenção & controle , Injúria Renal Aguda/metabolismo , Apoptose , Hipóxia/metabolismo , Hipóxia/patologia , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Isquemia , Rim/patologia , Proteínas de Membrana/metabolismo , Proteínas Mitocondriais , Mitofagia , Espécies Reativas de Oxigênio/metabolismo , Traumatismo por Reperfusão/metabolismo , Transdução de Sinais
10.
Orphanet J Rare Dis ; 19(1): 167, 2024 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-38637882

RESUMO

The report covers the current and past activities of the department Molecular Genetics-Function and Therapy (MGFT) at the Cyprus Institute of Neurology and Genetics (CING), an affiliated Reference Center for the European Reference Network on Rare Endocrine Conditions (Endo-ERN).The presented data is the outcome of > 15 years long standing collaboration between MGFT and endocrine specialists from the local government hospitals and the private sector. Up-to-date > 2000 genetic tests have been performed for the diagnosis of inherited rare endocrine disorders. The major clinical entities included Congenital Adrenal Hyperplasia (CAH) due to pathogenic variants in CYP21A2 gene and Multiple Endocrine Neoplasia (MEN) type 2 due to pathogenic variants in the RET proto-oncogene. Other rare and novel pathogenic variants in ANOS1, WDR11, FGFR1, RNF216, and CHD7 genes were also found in patients with Congenital Hypogonadotropic Hypogonadism. Interestingly, a few patients with Disorders of Sexual Differentiation (DSD) shared rare pathogenic variants in the SRD5A2, HSD17B3 and HSD3B2 while patients with Glucose and Insulin Homeostasis carried theirs in GCK and HNF1A genes. Lastly, MGFT over the last few years has established an esteemed diagnostic and research program on premature puberty with emphasis on the implication of MKRN3 gene on the onset of the disease and the identification of other prognosis biomarkers.As an Endo-ERN member MGFT department belongs to this large European network and holds the same humanistic ideals which aim toward the improvements of health care for patients with rare endocrine conditions in respect to improved and faster diagnosis.


Assuntos
Hiperplasia Suprarrenal Congênita , Doenças do Sistema Endócrino , Neoplasia Endócrina Múltipla Tipo 2a , Humanos , Chipre , Neoplasia Endócrina Múltipla Tipo 2a/diagnóstico , Neoplasia Endócrina Múltipla Tipo 2a/genética , Doenças do Sistema Endócrino/diagnóstico , Doenças do Sistema Endócrino/genética , Hiperplasia Suprarrenal Congênita/diagnóstico , Hiperplasia Suprarrenal Congênita/genética , Testes Genéticos , Ubiquitina-Proteína Ligases , Esteroide 21-Hidroxilase/genética , Proteínas de Membrana/genética , 3-Oxo-5-alfa-Esteroide 4-Desidrogenase
11.
Viral Immunol ; 37(3): 159-166, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38588555

RESUMO

The high global prevalence of hepatitis B and hepatitis C and the poor prognosis of hepatitis B and hepatitis C-associated hepatocellular carcinoma (HCC), necessitates the early diagnosis and treatment of the disease. Recent studies show that cell-to-cell communication via extracellular vesicles (EVs) is involved in the HCC progression. The objective of the following study was to explore the role of EVs in the progression of viral-induced HCC and investigate their potential for the early diagnosis of cancer. First, the mRNA derived from EVs of HCC patients was compared to the mRNA derived from EVs from the healthy controls. Expression analysis of ANGPTL3, SH3BGRL3, and IFITM3 genes from the EVs was done. Afterward, to confirm whether hepatocytes can uptake EVs, HuH7 cells were exposed to EVs, and the expression analysis of downstream target genes (AKT, TNF-α, and MMP-9) in Huh7 cells was done. Transcriptional analysis showed that in the EVs from HCC patients, the expression levels of ANGPTL3, SH3BGRL3, and IFITM3 were significantly increased by 2.62-, 4.3-, and 9.03-folds, respectively. The downstream targets, AKT, TNF-α, and MMP-9, also showed a considerable change of 4.1-, 1.46-, and 5.05-folds, respectively, in Huh7 cells exposed to HCC EVs. In conclusion, the following study corroborates the role of EVs in HCC progression. Furthermore, the significant alteration in mRNA levels of the selected genes demonstrates their potential to be used as possible biomarkers for the early diagnosis of HCC.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal , Carcinoma Hepatocelular , Vesículas Extracelulares , Hepatite B , Hepatite C , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/diagnóstico , Carcinoma Hepatocelular/genética , Neoplasias Hepáticas/diagnóstico , Neoplasias Hepáticas/genética , Metaloproteinase 9 da Matriz/metabolismo , Proteínas Proto-Oncogênicas c-akt , Fator de Necrose Tumoral alfa/metabolismo , Hepatite C/genética , Biomarcadores/metabolismo , Vesículas Extracelulares/metabolismo , Vesículas Extracelulares/patologia , RNA Mensageiro/genética , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Proteínas de Ligação a RNA/metabolismo , Proteína 3 Semelhante a Angiopoietina
12.
Front Immunol ; 15: 1375171, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38566986

RESUMO

Background: The underlying molecular pathways of idiopathic pulmonary fibrosis (IPF), a progressive lung condition with a high death rate, are still mostly unknown. By using microarray datasets, this study aims to identify new genetic targets for IPF and provide light on the genetic factors that contribute to the development of IPF. Method: We conducted a comprehensive analysis of three independent IPF datasets from the Gene Expression Omnibus (GEO) database, employing R software for data handling and normalization. Our evaluation of the relationships between differentially expressed genes (DEGs) and IPF included differential expression analysis, expression quantitative trait loci (eQTL) analysis, and Mendelian Randomization(MR) analyses. Additionally, we used Gene Set Enrichment Analysis (GSEA) and Gene Ontology (GO)/Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis to explore the functional roles and pathways of these genes. Finally, we validated the results obtained for the target genes. Results: We identified 486 highly expressed genes and 468 lowly expressed genes that play important roles in IPF. MR analysis identified six significantly co-expressed genes associated with IPF, specifically C12orf75, SPP1, ZG16B, LIN7A, PPP1R14A, and TLR2. These genes participate in essential biological processes and pathways, including macrophage activation and neural system regulation. Additionally, CIBERSORT analysis indicated a unique immune cell distribution in IPF, emphasized the significance of immunological processes in the disease. The MR analysis was consistent with the results of the analysis of variance in the validation cohort, which strengthens the reliability of our MR findings. Conclusion: Our findings provide new insights into the molecular basis of IPF and highlight the promise of therapeutic interventions. They emphasize the potential of targeting specific molecular pathways for the treatment of IPF, laying the foundation for further research and clinical work.


Assuntos
Perfilação da Expressão Gênica , Fibrose Pulmonar Idiopática , Humanos , Reprodutibilidade dos Testes , Fibrose Pulmonar Idiopática/genética , Bases de Dados Factuais , Ontologia Genética , Proteínas de Membrana , Proteínas de Transporte Vesicular
13.
J Mol Graph Model ; 129: 108764, 2024 06.
Artigo em Inglês | MEDLINE | ID: mdl-38581901

RESUMO

STING (stimulator of interferon genes) is a crucial protein in the innate immune system's response to viral and bacterial infections. In this study, we investigated the mechanistic and energetic mechanism of the conformational transition process of STING activated by cGAMP binding. We found that the STING connector region undergoes an energetically unfavorable rotation during this process, which is compensated by the favorable interaction between cGAMP and the STING ligand binding domain. We further studied several disease-causing mutations and found that the V155 M mutation facilitates a smoother transition in the STING connector region. However, the V147L mutation exhibits unfavorable conformational transition energy, suggesting it may hinder STING activation pathway that relies on connector region rotation. Despite being labeled as hyperactive, the widespread prevalence of V147L/V147I mutations across species implies a neutral character, indicating complexity in its role. Overall, our analysis deepens the understanding of STING activation within the connector region, and targeting this region with compounds may provide an alternative approach to interfering with STING's function.


Assuntos
Proteínas de Membrana , Proteínas de Membrana/química , Conformação Molecular , Mutação
14.
Proc Natl Acad Sci U S A ; 121(17): e2319476121, 2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38621120

RESUMO

Glycerophospholipids are synthesized primarily in the cytosolic leaflet of the endoplasmic reticulum (ER) membrane and must be equilibrated between bilayer leaflets to allow the ER and membranes derived from it to grow. Lipid equilibration is facilitated by integral membrane proteins called "scramblases." These proteins feature a hydrophilic groove allowing the polar heads of lipids to traverse the hydrophobic membrane interior, similar to a credit card moving through a reader. Nevertheless, despite their fundamental role in membrane expansion and dynamics, the identity of most scramblases has remained elusive. Here, combining biochemical reconstitution and molecular dynamics simulations, we show that lipid scrambling is a general feature of protein insertases, integral membrane proteins which insert polypeptide chains into membranes of the ER and organelles disconnected from vesicle trafficking. Our data indicate that lipid scrambling occurs in the same hydrophilic channel through which protein insertion takes place and that scrambling is abolished in the presence of nascent polypeptide chains. We propose that protein insertases could have a so-far-overlooked role in membrane dynamics as scramblases.


Assuntos
Proteínas de Membrana , Peptídeos , Membrana Celular/metabolismo , Proteínas de Membrana/metabolismo , Peptídeos/metabolismo , Membranas/metabolismo , Lipídeos , Bicamadas Lipídicas/química
15.
Zhongguo Zhong Yao Za Zhi ; 49(5): 1286-1294, 2024 Mar.
Artigo em Chinês | MEDLINE | ID: mdl-38621976

RESUMO

This study explored the specific mechanism by which tetrahydropalmatine(THP) inhibited mitophagy through the UNC-51-like kinase 1(ULK1)/FUN14 domain containing 1(FUNDC1) pathway to reduce hypoxia/reoxygenation(H/R) injury in H9c2 cells. This study used H9c2 cells as the research object to construct a cardiomyocyte H/R injury model. First, a cell viability detection kit was used to detect cell viability, and a micro-method was used to detect lactate dehydrogenase(LDH) leakage to evaluate the protective effect of THP on H/R injury of H9c2 cells. In order to evaluate the protective effect of THP on mitochondria, the chemical fluorescence method was used to detect intracellular reactive oxygen species, intramitochondrial reactive oxygen species, mitochondrial membrane potential, and autophagosomes, and the luciferin method was used to detect intracellular adenosine 5'-triphosphate(ATP) content. Western blot was further used to detect the ratio of microtubule-associated protein 1 light chain 3(LC3) membrane type(LC3-Ⅱ) and slurry type(LC3-Ⅰ) and activated cleaved caspase-3 expression level. In addition, ULK1 expression level and its phosphorylation degree at Ser555 site, as well as the FUNDC1 expression level and its phosphorylation degree of Ser17 site were detected to explore its specific mechanism. The results showed that THP effectively reduced mitochondrial damage in H9c2 cells after H/R. THP protected mitochondria by reducing the level of reactive oxygen species in cells and mitochondria, increasing mitochondrial membrane potential, thereby increasing cellular ATP production, enhancing cellular activity, reducing cellular LDH leakage, and finally alleviating H/R damage in H9c2 cells. Further studies have found that THP could reduce the production of autophagosomes, reduce the LC3-Ⅱ/LC3-Ⅰ ratio, and lower the expression of the apoptosis-related protein, namely cleaved caspase-3, indicating that THP could reduce apoptosis by inhibiting autophagy. In-depth studies have found that THP could inhibit the activation of the ULK1/FUNDC1 pathway of mitophagy and the occurrence of mitophagy by reducing the phosphorylation degree of ULK1 at Ser555 and FUNDC1 at Ser17. The application of ULK1 agonist BL-918 reversely verified the effect of THP on reducing the phosphorylation of ULK1 and FUNDC1. In summary, THP inhibited mitophagy through the ULK1/FUNDC1 pathway to reduce H/R injury in H9c2 cells.


Assuntos
Alcaloides de Berberina , Hipóxia , Mitofagia , Fenilacetatos , Humanos , Mitofagia/fisiologia , Caspase 3 , Espécies Reativas de Oxigênio/metabolismo , Apoptose , Trifosfato de Adenosina/farmacologia , Proteína Homóloga à Proteína-1 Relacionada à Autofagia/genética , Peptídeos e Proteínas de Sinalização Intracelular , Proteínas de Membrana/metabolismo , Proteínas Mitocondriais
16.
Biophys Chem ; 309: 107231, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38569455

RESUMO

Nanodisc technology is increasingly being used in structural, biochemical and biophysical studies of membrane proteins. The computational approaches have revealed many important features of nanodisc assembly, structures and dynamics. Therefore, we reviewed the application of computational approaches, especially molecular modeling and molecular dyncamics (MD) simulations, to characterize nanodiscs, including the structural models, assembly and disassembly, protocols for modeling, structural properties and dynamics, and protein-lipid interactions in nanodiscs. More amazing computational studies about nanodiscs are looked forward to in the future.


Assuntos
Nanoestruturas , Nanoestruturas/química , Bicamadas Lipídicas/química , Proteínas de Membrana/química , Modelos Moleculares
18.
Proc Natl Acad Sci U S A ; 121(17): e2321510121, 2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38635633

RESUMO

Levels of lipopolysaccharide (LPS), an essential glycolipid on the surface of most gram-negative bacteria, are tightly controlled-making LPS synthesis a promising target for developing new antibiotics. Escherichia coli adaptor protein LapB (YciM) plays an important role in regulating LPS synthesis by promoting degradation of LpxC, a deacetylase that catalyzes the first committed step in LPS synthesis. Under conditions where LPS is abundant, LapB recruits LpxC to the AAA+ protease FtsH for degradation. LapB achieves this by simultaneously interacting with FtsH through its transmembrane helix and LpxC through its cytoplasmic domain. Here, we describe a cryo-EM structure of the complex formed between LpxC and the cytoplasmic domain of LapB (LapBcyto). The structure reveals how LapB exploits both its tetratricopeptide repeat (TPR) motifs and rubredoxin domain to interact with LpxC. Through both in vitro and in vivo analysis, we show that mutations at the LapBcyto/LpxC interface prevent LpxC degradation. Unexpectedly, binding to LapBcyto also inhibits the enzymatic activity of LpxC through allosteric effects reminiscent of LpxC activation by MurA in Pseudomonas aeruginosa. Our findings argue that LapB regulates LPS synthesis in two steps: In the first step, LapB inhibits the activity of LpxC, and in the second step, it commits LpxC to degradation by FtsH.


Assuntos
Proteínas de Escherichia coli , Escherichia coli , Escherichia coli/metabolismo , Lipopolissacarídeos/metabolismo , Proteínas de Escherichia coli/metabolismo , Mutação , Rubredoxinas/metabolismo , Amidoidrolases/metabolismo , Proteínas de Membrana/metabolismo
19.
J Exp Clin Cancer Res ; 43(1): 98, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38561856

RESUMO

BACKGROUND: The complement inhibitor CSMD1 acts as a tumor suppressor in various types of solid cancers. Despite its high level of expression in the brain, its function in gliomas, malignant brain tumors originating from glial cells, has not been investigated. METHODS: Three cohorts of glioma patients comprising 1500 patients were analyzed in our study along with their clinical data. H4, U-118 and U-87 cell lines were used to investigate the tumor suppressor function of CSMD1 in gliomas. PDGFB-induced brain tumor model was utilized for the validation of in vitro data. RESULTS: The downregulation of CSMD1 expression correlated with reduced overall and disease-free survival, elevated tumor grade, wild-type IDH genotype, and intact 1p/19q status. Moreover, enhanced activity was noted in the neuroinflammation pathway. Importantly, ectopic expression of CSMD1 in glioma cell lines led to decreased aggressiveness in vitro. Mechanically, CSMD1 obstructed the TNF-induced NF-kB and STAT3 signaling pathways, effectively suppressing the secretion of IL-6 and IL-8. There was also reduced survival in PDGFB-induced brain tumors in mice when Csmd1 was downregulated. CONCLUSIONS: Our study has identified CSMD1 as a tumor suppressor in gliomas and elucidated its role in TNF-induced neuroinflammation, contributing to a deeper understanding of glioma pathogenesis.


Assuntos
Neoplasias Encefálicas , Glioma , Humanos , Animais , Camundongos , Doenças Neuroinflamatórias , Proteínas Proto-Oncogênicas c-sis/genética , Glioma/patologia , Neoplasias Encefálicas/patologia , Intervalo Livre de Doença , Isocitrato Desidrogenase/genética , Mutação , Proteínas de Membrana/genética , Proteínas Supressoras de Tumor/genética
20.
Mol Genet Genomic Med ; 12(4): e2425, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38562051

RESUMO

BACKGROUND: To explore the clinical application value of pre-conception expanded carrier screening (PECS) in the Chinese Han ethnicity population of childbearing age. METHODS: The results of genetic testing of infertile parents who underwent PECS in the Reproductive Medicine Center of the Second Affiliated Hospital of Zhengzhou University, China, from September 2019 to December 2021, were retrospectively analyzed. The carrier rate of single gene disease, the detection rate of high-risk parents, and the clinical outcome of high-risk parents were statistically analyzed. RESULTS: A total of 1372 Chinese Han ethnicity patients underwent PECS, among which 458 patients underwent the extended 108-gene test, their overall carrier rate was 31.7%, and the detection rate of high-risk parents was 0.3%. The highest carrier rates were SLC22A (2.4%), ATP7B (2.4%), MMACHC (2.2%), PAH (1.8%), GALC (1.8%), MLC1 (1.3%), UNC13D (1.1%), CAPN3 (1.1%), and PKHD1 (1.1%). There were 488 women with fragile X syndrome-FMR1 gene detection, and 6 patients (1.2%) had FMR1 gene mutation. A total of 426 patients were screened for spinal muscular atrophy-SMN1, and the carrier rate was 3.5%, and the detection rate of parents' co-carrier was 0.5%. CONCLUSION: Monogenic recessive hereditary diseases had a high carrier rate in the population. Pre-pregnancy screening could provide good prenatal and postnatal care guidance for patients and preimplantation genetic testing for monogenic/single gene disorders (PGT-M) and prenatal diagnosis could provide more precise reproductive choices for high-risk parents.


Assuntos
Testes Genéticos , Atrofia Muscular Espinal , Gravidez , Humanos , Feminino , Estudos Retrospectivos , Testes Genéticos/métodos , Diagnóstico Pré-Natal/métodos , Mutação , Atrofia Muscular Espinal/genética , Proteína do X Frágil de Retardo Mental/genética , Oxirredutases/genética , Proteínas de Membrana/genética
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