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1.
ACS Nano ; 18(14): 10288-10301, 2024 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-38556985

RESUMO

Insufficient reactive oxygen species (ROS) production and radioresistance have consistently contributed to the failure of radiotherapy (RT). The development of a biomaterial capable of activating ROS-induced apoptosis and ferroptosis is a potential strategy to enhance RT sensitivity. To achieve precision and high-efficiency RT, the theranostic nanoplatform Au/Cu nanodots (Au/CuNDs) were designed for dual-mode imaging, amplifying ROS generation, and inducing apoptosis-ferroptosis to sensitize RT. A large amount of ROS is derived from three aspects: (1) When exposed to ionizing radiation, Au/CuNDs effectively absorb photons and emit various electrons, which can interact with water to produce ROS. (2) Au/CuNDs act as a catalase-like to produce abundant ROS through Fenton reaction with hydrogen peroxide overexpressed of tumor cells. (3) Au/CuNDs deplete overexpressed glutathione, which causes the accumulation of ROS. Large amounts of ROS and ionizing radiation further lead to apoptosis by increasing DNA damage, and ferroptosis by enhancing lipid peroxidation, significantly improving the therapeutic efficiency of RT. Furthermore, Au/CuNDs serve as an excellent nanoprobe for high-resolution near-infrared fluorescence imaging and computed tomography of tumors. The promising dual-mode imaging performance shows their potential application in clinical cancer detection and imaging-guided precision RT, minimizing damage to adjacent normal tissues during RT. In summary, our developed theranostic nanoplatform integrates dual-mode imaging and sensitizes RT via ROS-activated apoptosis-ferroptosis, offering a promising prospect for clinical cancer diagnosis and treatment.


Assuntos
Ferroptose , Neoplasias , Radioterapia Guiada por Imagem , Humanos , Espécies Reativas de Oxigênio , Neoplasias/diagnóstico por imagem , Neoplasias/radioterapia , Apoptose , Peróxido de Hidrogênio , Linhagem Celular Tumoral
3.
Cell Death Discov ; 10(1): 155, 2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38538596

RESUMO

Senile osteoporosis is mainly caused by osteoblasts attenuation, which results in reduced bone mass and disrupted bone remodeling. Numerous studies have focused on the regulatory role of m6A modification in osteoporosis; however, most of the studies have investigated the differentiation of bone marrow mesenchymal stem cells (BMSCs), while the direct regulatory mechanism of m6A on osteoblasts remains unknown. This study revealed that the progression of senile osteoporosis is closely related to the downregulation of m6A modification and methyltransferase-like 3 (METTL3). Overexpression of METTL3 inhibits osteoblast aging. Methylated RNA immunoprecipitation sequencing (MeRIP-seq) revealed that METTL3 upregulates the stability of Hspa1a mRNA, thereby inhibiting osteoblast aging. Moreover, the results demonstrated that METTL3 enhances the stability of Hspa1a mRNA via m6A modification to regulate osteoblast aging. Notably, YTH N6-methyladenosine RNA binding protein 2 (YTHDF2) participates in stabilizing Hspa1a mRNA in the METTL3-mediated m6A modification process, rather than the well-known degradation function. Mechanistically, METTL3 increases the stability of Hspa1a mRNA in a YTHDF2-dependent manner to inhibit osteoblast aging. Our results confirmed the significant role of METTL3 in osteoblast aging and suggested that METTL3 could be a potential therapeutic target for senile osteoporosis.

5.
bioRxiv ; 2024 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-38370615

RESUMO

Facultative heterochromatinization of genomic regulators by Polycomb repressive complex (PRC) 1 and 2 is essential in development and differentiation; however, the underlying molecular mechanisms remain obscure. Using genetic engineering, molecular approaches, and live-cell single-molecule imaging, we quantify the number of proteins within condensates formed through liquid-liquid phase separation (LLPS) and find that in mouse embryonic stem cells (mESCs), approximately 3 CBX2 proteins nucleate many PRC1 and PRC2 subunits to form one non-stoichiometric condensate. We demonstrate that sparse CBX2 prevents Polycomb proteins from migrating to constitutive heterochromatin, demarcates the spatial boundaries of facultative heterochromatin, controls the deposition of H3K27me3, regulates transcription, and impacts cellular differentiation. Furthermore, we show that LLPS of CBX2 is required for the demarcation and deposition of H3K27me3 and is essential for cellular differentiation. Our findings uncover new functional roles of LLPS in the formation of facultative heterochromatin and unravel a new mechanism by which low-abundant proteins nucleate many other proteins to form compartments that enable them to execute their functions.

6.
Cell Signal ; 115: 111038, 2024 03.
Artigo em Inglês | MEDLINE | ID: mdl-38195035

RESUMO

N6-methyladenosine (m6A), the most prevalent internal modification in mRNA, is related to the pathogenesis of osteoporosis (OP). Although methyltransferase Like-3 (METTL3), an m6A transferase, has been shown to mitigate OP progression, the mechanisms of METTL3-mediated m6A modification in osteoblast function remain unclear. Here, fluid shear stress (FSS) induced osteoblast proliferation and differentiation, resulting in elevated levels of METTL3 expression and m6A modification. Through Methylated RNA Immunoprecipitation Sequencing (MeRIP-seq) and Transcriptomic RNA Sequencing (RNA-seq), SRY (Sex Determining Region Y)-box 4 (SOX4) was screened as a target of METTL3, whose m6A-modified coding sequence (CDS) regions exhibited binding affinity towards METTL3. Further functional experiments demonstrated that knockdown of METTL3 and SOX4 hampered osteogenesis, and METTL3 knockdown compromised SOX4 mRNA stability. Via RNA immunoprecipitation (RIP) assays, we further confirmed the direct interaction between METTL3 and SOX4. YTH N6-Methyladenosine RNA Binding Protein 3 (YTHDF3) was identified as the m6A reader responsible for modulating SOX4 mRNA and protein levels by affecting its degradation. Furthermore, in vivo experiments demonstrated that bone loss in an ovariectomized (OVX) mouse model was reversed through the overexpression of SOX4 mediated by adeno-associated virus serotype 2 (AAV2). In conclusion, our research demonstrates that METTL3-mediated m6A modification of SOX4 plays a crucial role in regulating osteoblast proliferation and differentiation through its recognition by YTHDF3. Our research confirms METTL3-m6A-SOX4-YTHDF3 as an essential axis and potential mechanism in OP.


Assuntos
Metiltransferases , Osteoblastos , Animais , Camundongos , Proliferação de Células , Metiltransferases/metabolismo , Osteoblastos/metabolismo , RNA , RNA Mensageiro/metabolismo
7.
Anal Chem ; 95(48): 17595-17602, 2023 12 05.
Artigo em Inglês | MEDLINE | ID: mdl-37974422

RESUMO

N6-Methyladenosine (m6A) stands out as the predominant internal modification in mammalian RNA, exerting crucial regulatory functions in the metabolism of mRNA. Currently available methods have been limited by an inability to quantify m6A modification at precise sites. In this work, we screened a Bst 2.0 warm start DNA polymerase with the capability of discriminating m6A from adenosine (A) and developed a robust m6A RNA detection method that enables isothermal and ultrasensitive quantification of m6A RNA at single-base resolution. The detection limit of the assay could reach about 0.02 amol, and the quantitative accuracy of the assay was verified in real cell samples. Furthermore, we applied this assay to single-cell analysis and found that the coefficients of variation of the MALAT1 m6A 2611 site in glioblastoma U251 cells showed over 20% higher than in oligodendrocytes MO3.13 cells. This method provides a highly sensitive analytical tool for site-specific m6A detection and quantification, which is expected to provide a basis for precise disease diagnosis and epigenetic transcriptional regulation.


Assuntos
Adenosina , RNA , Animais , RNA/genética , RNA Mensageiro/genética , Adenosina/metabolismo , Mamíferos/metabolismo
8.
Exploration (Beijing) ; 3(5): 20220175, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37933281

RESUMO

Gliomas are histologically and genetically heterogeneous tumors. However, classical histopathological typing often ignores the high heterogeneity of tumors and thus cannot meet the requirements of precise pathological diagnosis. Here, proximity-anchored in situ spectral coding amplification (ProxISCA) is proposed for multiplexed imaging of RNA mutations, enabling visual typing of brain gliomas with different pathological grades at the single-cell and tissue levels. The ligation-based padlock probe can discriminate one-nucleotide variations, and the design of proximity primers enables the anchoring of amplicons on target RNA, thus improving localization accuracy. The DNA module-based spectral coding strategy can dramatically improve the multiplexing capacity for imaging RNA mutations through one-time labelling, with low cost and simple operation. One-target-one-amplicon amplification confers ProxISCA the ability to quantify RNA mutation copy number with single-molecule resolution. Based on this approach, it is found that gliomas with higher malignant grades express more genes with high correlation at the cellular and tissue levels and show greater cellular heterogeneity. ProxISCA provides a tool for glioma research and precise diagnosis, which can reveal the relationship between cellular heterogeneity and glioma occurrence or development and assist in pathological prognosis.

9.
ACS Cent Sci ; 9(10): 1976-1988, 2023 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-37901175

RESUMO

Surgery, radiotherapy (RT), and brachytherapy are crucial treatments for localized deep tumors. However, imprecise tumor location often leads to issues such as positive surgical margins, extended radiotherapy target volumes, and radiation damage to healthy tissues. Reducing side effects in healthy tissue and enhancing RT efficacy are critical challenges. To address these issues, we developed a multifunctional theranostic platform using Au/Ag nanodots (Au/AgNDs) that act as a "pilot light" for real-time guided surgery, high-efficiency RT, and brachytherapy, achieving a strategy of killing three birds with one stone. First, dual-mode imaging of Au/AgNDs enabled precision RT, minimizing damage to adjacent normal tissue during X-ray irradiation. Au/AgNDs enhanced ionizing radiation energy deposition, increased intracellular reactive oxygen species (ROS) generation, regulated the cell cycle, promoted DNA damage formation, and inhibited DNA repair in tumor cells, significantly improving RT efficacy. Second, in brachytherapy, precise guidance provided by dual-mode imaging addressed challenges related to non-visualization of existing interstitial brachytherapy and multiple adjustments of insertion needle positions. Meanwhile, the effect of brachytherapy was improved. Third, the excellent fluorescence imaging of Au/AgNDs accurately distinguished tumors from normal tissue, facilitating their use as a powerful tool for assisting surgeons during tumor resection. Taken together, our multifunctional theranostic platform offers real-time guidance for surgery and high-efficiency RT, and improves brachytherapy precision, providing a novel strategy and vision for the clinical diagnosis and treatment of cancer.

10.
Cell Rep ; 42(10): 113136, 2023 10 31.
Artigo em Inglês | MEDLINE | ID: mdl-37756159

RESUMO

Polycomb repressive complex 1 (PRC1) undergoes phase separation to form Polycomb condensates that are multi-component hubs for silencing Polycomb target genes. In this study, we demonstrate that formation and regulation of PRC1 condensates are consistent with the scaffold-client model, where the Chromobox 2 (CBX2) protein behaves as the scaffold while the other PRC1 proteins are clients. Such clients induce a re-entrant phase transition of CBX2 condensates. The composition of the multi-component PRC1 condensates (1) determines the dynamic properties of the scaffold protein; (2) selectively promotes the formation of CBX4-PRC1 condensates while dissolving condensates of CBX6-, CBX7-, and CBX8-PRC1; and (3) controls the enrichment of CBX4-, CBX7-, and CBX8-PRC1 in CBX2-PRC1 condensates and the exclusion of CBX6-PRC1 from CBX2-PRC1 condensates. Our findings uncover how multi-component PRC1 condensates are assembled via an intricate scaffold-client mechanism whereby the properties of the PRC1 condensates are sensitively regulated by its composition and stoichiometry.


Assuntos
Núcleo Celular , Complexo Repressor Polycomb 1 , Humanos , Complexo Repressor Polycomb 1/genética , Complexo Repressor Polycomb 1/metabolismo , Núcleo Celular/metabolismo , Proteínas do Grupo Polycomb/genética , Proteínas do Grupo Polycomb/metabolismo , Cromatina/metabolismo , Ligases/genética
11.
PLoS One ; 18(9): e0291359, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37683034

RESUMO

Smoke and fire detection technology is a key technology for automatically realizing forest monitoring and forest fire warning. One of the most popular algorithms for object detection tasks is YOLOv5. However, it suffers from some challenges, such as high computational load and limited detection performance. This paper proposes a high-performance lightweight network model for detecting forest smoke and fire based on YOLOv5 to overcome these problems. C3Ghost and Ghost modules are introduced into the Backbone and Neck network to achieve the purpose of reducing network parameters and improving the feature's expressing performance. Coordinate Attention (CA) module is introduced into the Backbone network to highlight the object's important information about smoke and fire and to suppress irrelevant background information. In Neck network part, in order to distinguish the importance of different features in feature fusing process, the weight parameter of feature fusion is added which is based on PAN (path aggregation network) structure, which is named PAN-weight. Multiple sets of controlled experiments were conducted to confirm the proposed method's performance. Compared with YOLOv5s, the proposed method reduced the model size and FLOPs by 44.75% and 47.46% respectively, while increased precision and mAP(mean average precision)@0.5 by 2.53% and 1.16% respectively. The experimental results demonstrated the usefulness and superiority of the proposed method. The core code and dataset required for the experiment are saved in this article at https://github.com/vinchole/zzzccc.git.


Assuntos
Incêndios , Incêndios Florestais , Fumaça , Algoritmos , Florestas
12.
Cell Tissue Res ; 394(2): 379-392, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37759141

RESUMO

Despite the high complete response rate of fertility-sparing treatment in early-stage endometrial cancer (EC), the low pregnancy rate is a clinical challenge. Whether endometrium-derived mesenchymal stem cells (eMSCs) can repair damaged endometrium after EC reversal remains unclear. This study explored the potential therapeutic effects of eMSCs with suitable scaffold materials on endometrial damage caused by EC. Here, appropriate engineering scaffold materials were compared to identify the most suitable materials to carry eMSCs. Then, safety and efficacy evaluations of eMSCs with a suitable hyaluronic acid hydrogel (eMSCs/HA-GEL) were investigated in in vivo experiments with subcutaneous xenotransplantation in Balb/C nude mice and a model of endometrial mechanical injury in rats. HA-GEL has minimal cytotoxicity to eMSCs compared to other materials. Then, in vitro experiments demonstrate that eMSCs/HA-GEL enhance the inhibitory effects of progestins on EC cell biological behaviors. eMSCs/HA-GEL significantly inhibit EC cell growth and have no potential safety hazards of spontaneous tumorigenesis in Balb/C nude mouse subcutaneous xenotransplantation assays. eMSCs/HA-GEL intrauterine transplantation effectively increases endometrial thickness and glandular number, improves endometrial blood supply, reduces fibrotic areas, and improves pregnancy rates in a rat endometrial mechanical injury model. GFP-eMSCs/HA-GEL intrauterine transplantation in rats shows more GFP-eMSCs in the endometrium than GFP-eMSCs transplantation alone, and no tumor formation or suspicious cell nodules are found in the liver, kidney, or lung tissues. Our results reveal the safety and efficacy of eMSCs/HA-GEL in animal models and provide preliminary evidence for the use of eMSCs/HA-GEL as a treatment for EC-related endometrial damage.


Assuntos
Neoplasias do Endométrio , Células-Tronco Mesenquimais , Camundongos , Humanos , Feminino , Ratos , Animais , Camundongos Nus , Endométrio/patologia , Células-Tronco Mesenquimais/fisiologia , Neoplasias do Endométrio/terapia , Neoplasias do Endométrio/patologia , Transplante Heterólogo
13.
Molecules ; 28(14)2023 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-37513400

RESUMO

The RNA contained in exosomes plays a crucial role in information transfer between cells in various life activities. The accurate detection of low-abundance exosome RNA (exRNA) is of great significance for cell function studies and the early diagnosis of diseases. However, their intrinsic properties, such as their short length and high sequence homology, represent great challenges for exRNA detection. In this paper, we developed a dual-signal isothermal amplification method based on rolling circle amplification (RCA) coupled with DNAzyme (RCA-DNAzyme). The sensitive detection of low-abundance exRNA, the specific recognition of their targets and the amplification of the detection signal were studied and explored. By designing padlock probes to specifically bind to the target exRNA, while relying on the ligation reaction to enhance recognition, the precise targeting of exosome RNA was realized. The combination of RCA and DNAzyme could achieve a twice-as-large isothermal amplification of the signal compared to RCA alone. This RCA-DNAzyme assay could sensitively detect a target exRNA at a concentration as low as 527 fM and could effectively distinguish the target from other miRNA sequences. In addition, this technology was successfully proven to be effective for the quantitative detection of miR-21 by spike recovery, providing a new research approach for the accurate detection of low-abundance exRNA and the exploration of unknown exRNA functions.


Assuntos
Técnicas Biossensoriais , DNA Catalítico , Exossomos , MicroRNAs , DNA Catalítico/metabolismo , Exossomos/genética , Exossomos/metabolismo , Técnicas de Amplificação de Ácido Nucleico/métodos , MicroRNAs/genética , Bioensaio , Técnicas Biossensoriais/métodos , Limite de Detecção
14.
BMC Nephrol ; 24(1): 202, 2023 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-37407942

RESUMO

BACKGROUND: Minimal change disease (MCD), a pathological type of nephrotic syndrome (NS), can occur in patients with tumors. We report two adult cases of MCD associated with papillary thyroid carcinoma (PTC), known to be extremely rare in adults. CASE PRESENTATION: A 35-year-old female patient was simultaneously diagnosed with MCD and PTC. The MCD was effectively treated with thyroidectomy and prednisone.In addition, a 50-year-old male patient, who had been diagnosed with PTC three years prior, had MCD confirmed by renal biopsy. The patient achieved complete remission following treatment with tacrolimus and rituximab. CONCLUSIONS: The present case report describes and discusses the diagnostic and treatment processes employed in these two patients. Clinicians need to be aware of the renal effects of treating patients with solid tumors.


Assuntos
Nefrose Lipoide , Câncer Papilífero da Tireoide , Neoplasias da Glândula Tireoide , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Nefrose Lipoide/complicações , Nefrose Lipoide/diagnóstico , Nefrose Lipoide/terapia , Prednisona/uso terapêutico , Câncer Papilífero da Tireoide/complicações , Neoplasias da Glândula Tireoide/complicações , Tireoidectomia , Síndrome Nefrótica
15.
Cell Discov ; 9(1): 76, 2023 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-37488138

RESUMO

IscU2 is a scaffold protein that is critical for the assembly of iron-sulfur (Fe-S) clusters and the functions of Fe-S-containing mitochondrial proteins. However, the role of IscU2 in tumor development remains unclear. Here, we demonstrated that IscU2 expression is much higher in human pancreatic ductal adenocarcinoma (PDAC) tissues than in adjacent normal pancreatic tissues. In PDAC cells, activated KRAS enhances the c-Myc-mediated IscU2 transcription. The upregulated IscU2 stabilizes Fe-S cluster and regulates the activity of tricarboxylic acid (TCA) cycle enzymes α-ketoglutarate (α-KG) dehydrogenase and aconitase 2, which promote α-KG catabolism through oxidative and reductive TCA cycling, respectively. In addition to promoting mitochondrial functions, activated KRAS-induced and IscU2-dependent acceleration of α-KG catabolism results in reduced α-KG levels in the cytosol and nucleus, leading to an increase in DNA 5mC due to Tet methylcytosine dioxygenase 3 (TET3) inhibition and subsequent expression of genes including DNA polymerase alpha 1 catalytic subunit for PDAC cell proliferation and tumor growth in mice. These findings underscore a critical role of IscU2 in KRAS-promoted α-KG catabolism, 5mC-dependent gene expression, and PDAC growth and highlight the instrumental and integrated regulation of mitochondrial functions and gene expression by IscU2 in PDAC cells.

16.
AAPS J ; 25(4): 60, 2023 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-37322223

RESUMO

Current regulatory guidelines on drug-food interactions recommend an early assessment of food effect to inform clinical dosing instructions, as well as a pivotal food effect study on the to-be-marketed formulation if different from that used in earlier trials. Study waivers are currently only granted for BCS class 1 drugs. Thus, repeated food effect studies are prevalent in clinical development, with the initial evaluation conducted as early as the first-in-human studies. Information on repeated food effect studies is not common in the public domain. The goal of the work presented in this manuscript from the Food Effect PBPK IQ Working Group was to compile a dataset on these studies across pharmaceutical companies and provide recommendations on their conduct. Based on 54 studies collected, we report that most of the repeat food effect studies do not result in meaningful differences in the assessment of the food effect. Seldom changes observed were more than twofold. There was no clear relationship between the change in food effect and the formulation change, indicating that in most cases, once a compound is formulated appropriately within a specific formulation technology, the food effect is primarily driven by inherent compound properties. Representative examples of PBPK models demonstrate that following appropriate validation of the model with the initial food effect study, the models can be applied to future formulations. We recommend that repeat food effect studies should be approached on a case-by-case basis taking into account the totality of the evidence including the use of PBPK modeling.


Assuntos
Interações Alimento-Droga , Modelos Biológicos , Humanos , Solubilidade , Simulação por Computador , Alimentos
17.
J Oncol Pharm Pract ; 29(7): 1781-1784, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37338466

RESUMO

INTRODUCTION: Non-small cell lung cancer (NSCLC) is the most common histological subtype of lung cancer. Osimertinib has been recommended as first-line treatment of advanced NSCLC with EGFR mutations. Previous studies have only reported cases of gastrointestinal bleeding due to Erlotinib and gefitinib, but to date, always no cases of gastrointestinal bleeding due to Osimertinib have been reported. CASE REPORT: We report a case of a female patient with NSCLC with EFGR mutation. After 1.5 years of treatment with Osimertinib, a colonoscopy showed diffuse congestion of the colonic mucosa. MANAGEMENT AND OUTCOME: The patient's symptoms of blood in the stool disappeared, after stopping Osimertinib and giving mucosal protection treatment for 1 week. DISCUSSION: Osimertinib may have contributed to gastrointestinal bleeding because no recurrent bleeding was observed after discontinuation of treatment. Physicians and patients should be aware that osimertinib may increase the risk of gastrointestinal bleeding.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Humanos , Feminino , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Inibidores de Proteínas Quinases/efeitos adversos , Receptores ErbB/genética , Compostos de Anilina/efeitos adversos , Mutação , Hemorragia Gastrointestinal/induzido quimicamente
18.
Front Microbiol ; 14: 1084205, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36876095

RESUMO

Escherichia coli cysteine desulfurase (CD), IscS, modifies basal metabolism by transferring sulphur (S) from L-cysteine to numerous cellular pathways, whereas NFS1, a human CD, is active only in the formation of the [Acp]2:[ISD11]2:[NFS1]2 complex. Despite the accumulation of red-coloured IscS in E. coli cells as a result of the deficiency of accessible iron, as revealed in our previous studies, the mechanism of the potential enzymatic reaction remains unclear. In this study, the N-terminus of IscS was fused with the C-terminus of NFS1, which was reported to be almost fully active as IscS and exhibits a pyridoxal 5'-phosphate (PLP) absorption peak at 395 nm. Moreover, SUMO-EH-IscS exhibited significant growth recovery and NADH-dehydrogenase I activity in the iscS mutant cells. Furthermore, through in vitro and in vivo experiments combined with high-performance liquid chromatography and ultra-performance liquid chromatography-tandem mass spectrometry, it was shown that the new absorption peaks of the IscS H104Q, IscS Q183E, IscS K206A, and IscS K206A&C328S variants at 340 and 350 nm may correspond to the enzyme reaction intermediates, Cys-ketimine and Cys-aldimine, respectively. However, after mutation of the conserved active-site residues, additional absorption peaks at 420 and 430 nm were associated with PLP migration in the active-site pocket. Additionally, the corresponding absorption peaks of Cys-quinonoid, Ala-ketimine, and Ala-aldimine intermediates in IscS were 510, 325, and 345 nm, respectively, as determined by site-directed mutagenesis and substrate/product-binding analyses during the CD reaction process. Notably, red IscS formed in vitro by incubating IscS variants (Q183E and K206A) with excess L-alanine and sulphide under aerobic conditions produced an absorption peak similar to the wild-type IscS, at 510 nm. Interestingly, site-directed mutation of IscS with hydrogen bonds to PLP at Asp180 and Gln183 resulted in a loss of enzymatic activity followed by an absorption peak consistent with NFS1 (420 nm). Furthermore, mutations at Asp180 or Lys206 inhibited the reaction of IscS in vitro with L-cysteine (substrate) and L-alanine (product). These results suggest that the conserved active site residues (His104, Asp180, and Gln183) and their hydrogen bond with PLP in the N-terminus of IscS play a key role in determining whether the L-cysteine substrate can enter the active-site pocket and regulate the enzymatic reaction process. Therefore, our findings provide a framework for evaluating the roles of conserved active-site residues, motifs, and domains in CDs.

19.
Genes (Basel) ; 14(3)2023 03 18.
Artigo em Inglês | MEDLINE | ID: mdl-36981015

RESUMO

BACKGROUND: HLRCC syndrome is a hereditary cancer predisposition syndrome caused by heterozygous germline pathogenic variant of the fumarate hydratase (FH) gene and characterized by cutaneous leiomyomas (CL), uterine leiomyomas (UL), and renal cell carcinoma (RCC). Loss of function variant of FH gene inactivates the Kreb's cycle enzyme activity and predisposes individuals with such variant to the development of HLRCC. METHODS: Next-generation sequencing (NGS) and Sanger confirmation were given to family members accessible. Following that, a functional study in vitro was performed to further confirm the pathogenicity of the variant. FH-Wild type (FH-WT) and FH-mutant (FH-MUT) (E378K) plasmid were constructed and transfected into 293T and uterine leiomyoma cell lines, respectively. Proliferation assessment was executed to show how this mutation affects the growth of uterine leiomyoma. qPCR and Western blotting were performed to investigate the change of transcription and translation of FH with mutation (E378K), and FH enzyme assay activity were tested in 293T cells with mutation and wild-type plasmids. RESULTS: Here, we presented two families with the same missense variant (c.1132G > A) that has not been reported as a germline mutation in hereditary uterine leiomyomas before and classified as VUS in gene databases. Our in vitro experiments supported the pathogenicity of this missense variant, especially in uterine leiomyomata. CONCLUSIONS: According to the American College of Medical Genetics (ACMG) guideline, the E378K variant was classified as likely pathogenic (with evidence PS4_support, PS3_support, PM2_support, PP1, PP3 and PP4 evidence). Further insights into clinical management in uterine leiomyomata were discussed and should be practiced in gynecological clinical settings.


Assuntos
Neoplasias Renais , Leiomiomatose , Neoplasias Uterinas , Feminino , Humanos , Fumarato Hidratase/genética , Fumarato Hidratase/análise , Neoplasias Renais/genética , Leiomiomatose/genética , Leiomiomatose/patologia , Mutação de Sentido Incorreto , Síndrome , Neoplasias Uterinas/genética , Neoplasias Uterinas/patologia
20.
Biomater Sci ; 11(4): 1116-1136, 2023 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-36601661

RESUMO

Radiotherapy (RT) is one of the most effective and commonly used cancer treatments for malignant tumors. However, the existing radiosensitizers have a lot of side effects and poor efficacy, which limits the curative effect and further application of radiotherapy. In recent years, emerging nanomaterials have shown unique advantages in enhancing radiosensitization. In particular, gold-based nanomaterials, with high X-ray attenuation capacity, good biocompatibility, and promising chemical, electronic and optical properties, have become a new type of radiotherapy sensitizer. In addition, gold-based nanomaterials can be used as a carrier to load a variety of drugs and immunosuppressants; in particular, its photothermal therapy, photodynamic therapy and multi-mode imaging functions aid in providing excellent therapeutic effect in coordination with RT. Recently, many novel strategies of radiosensitization mediated by multifunctional gold-based nanomaterials have been reported, which provides a new idea for improving the efficacy and reducing the side effects of RT. In this review, we systematically summarize the recent progress of various new gold-based nanomaterials that mediate radiosensitization and describe the mechanism. We further discuss the challenges and prospects in the field. It is hoped that this review will help researchers understand the latest progress of gold-based nanomaterials for radiosensitization, and encourage people to optimize the existing methods or explore novel approaches for radiotherapy.


Assuntos
Nanopartículas Metálicas , Nanoestruturas , Neoplasias , Radiossensibilizantes , Humanos , Ouro/química , Nanopartículas Metálicas/química , Neoplasias/tratamento farmacológico , Neoplasias/radioterapia , Radiossensibilizantes/química
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