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1.
Nucleic Acids Res ; 52(3): 1136-1155, 2024 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-38038252

RESUMO

Maintaining chromatin integrity at the repetitive non-coding DNA sequences underlying centromeres is crucial to prevent replicative stress, DNA breaks and genomic instability. The concerted action of transcriptional repressors, chromatin remodelling complexes and epigenetic factors controls transcription and chromatin structure in these regions. The histone chaperone complex ATRX/DAXX is involved in the establishment and maintenance of centromeric chromatin through the deposition of the histone variant H3.3. ATRX and DAXX have also evolved mutually-independent functions in transcription and chromatin dynamics. Here, using paediatric glioma and pancreatic neuroendocrine tumor cell lines, we identify a novel ATRX-independent function for DAXX in promoting genome stability by preventing transcription-associated R-loop accumulation and DNA double-strand break formation at centromeres. This function of DAXX required its interaction with histone H3.3 but was independent of H3.3 deposition and did not reflect a role in the repression of centromeric transcription. DAXX depletion mobilized BRCA1 at centromeres, in line with BRCA1 role in counteracting centromeric R-loop accumulation. Our results provide novel insights into the mechanisms protecting the human genome from chromosomal instability, as well as potential perspectives in the treatment of cancers with DAXX alterations.


Assuntos
Centrômero , Quebras de DNA de Cadeia Dupla , Chaperonas Moleculares , Proteínas Nucleares , Estruturas R-Loop , Proteína Nuclear Ligada ao X , Criança , Humanos , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Centrômero/metabolismo , Cromatina , Proteínas Correpressoras/metabolismo , DNA , Histonas/genética , Histonas/metabolismo , Chaperonas Moleculares/genética , Chaperonas Moleculares/metabolismo , Proteínas Nucleares/metabolismo , Fatores de Transcrição/metabolismo , Proteína Nuclear Ligada ao X/genética , Proteína Nuclear Ligada ao X/metabolismo
2.
Nucleic Acids Res ; 51(4): e22, 2023 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-36629249

RESUMO

During each cell division, tens of thousands of DNA replication origins are co-ordinately activated to ensure the complete duplication of the human genome. However, replication fork progression can be challenged by many factors, including co-directional and head-on transcription-replication conflicts (TRC). Head-on TRCs are more dangerous for genome integrity. To study the direction of replication fork movement and TRCs, we developed a bioinformatics toolkit called OKseqHMM (https://github.com/CL-CHEN-Lab/OK-Seq, https://doi.org/10.5281/zenodo.7428883). Then, we used OKseqHMM to analyse a large number of datasets obtained by Okazaki fragment sequencing to directly measure the genome-wide replication fork directionality (RFD) and to accurately predict replication initiation and termination at a fine resolution in organisms including yeast, mouse and human. We also successfully applied our analysis to other genome-wide sequencing techniques that also contain RFD information (e.g. eSPAN, TrAEL-seq). Our toolkit can be used to predict replication initiation and fork progression direction genome-wide in a wide range of cell models and growth conditions. Comparing the replication and transcription directions allows identifying loci at risk of TRCs, particularly head-on TRCs, and investigating their role in genome instability by checking DNA damage data, which is of prime importance for human health.


Assuntos
Replicação do DNA , Instabilidade Genômica , Software , Animais , Humanos , Camundongos , Dano ao DNA , Origem de Replicação , Saccharomyces cerevisiae/genética
3.
J Exp Bot ; 75(7): 1967-1981, 2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38069503

RESUMO

Within a spike of wheat, the central spikelets usually generate three to four fertile florets, while the basal spikelets generate zero to one fertile floret. The physiological and transcriptional mechanism behind the difference in fertility between the basal and central spikelets is unclear. This study reports a high temporal resolution investigation of transcriptomes, number and morphology of floret primordia, and physiological traits. The W6.5-W7.5 stage was regarded as the boundary to distinguish between fertile and abortive floret primordia; those floret primordia reaching the W6.5-W7.5 stage during the differentiation phase (3-9 d after terminal spikelet stage) usually developed into fertile florets in the next dimorphism phase (12-27 d after terminal spikelet stage), whereas the others aborted. The central spikelets had a greater number of fertile florets than the basal spikelets, which was associated with more floret primordia reaching the W6.5-W7.5 stage. Physiological and transcriptional results demonstrated that the central spikelets had a higher sucrose content and lower abscisic acid (ABA) and jasmonic acid (JA) accumulation than the basal spikelets due to down-regulation of genes involved in ABA and JA synthesis. Collectively, we propose a model in which ABA and JA accumulation is induced under limiting sucrose availability (basal spikelet) through the up-regulation of genes involved in ABA and JA synthesis; this leads to floret primordia in the basal spikelets failing to reach their fertile potential (W6.5-W7.5 stage) during the differentiation phase and then aborting. This fertility repression model may also regulate spikelet fertility in other cereal crops and potentially provides genetic resources to improve spikelet fertility.


Assuntos
Ácido Abscísico , Ciclopentanos , Flores , Oxilipinas , Sulfonamidas , Flores/genética , Triticum/genética , Sacarose , Fertilidade/genética
4.
Neurochem Res ; 49(4): 1105-1120, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38289520

RESUMO

Reduced myelin stability observed in the early stages of Alzheimer's disease leads to spatial learning and memory impairment. Exercise has been shown to protect nerves, reduce the risk of Alzheimer's disease, and strengthen synaptic connectivity. However, the underlying mechanisms of how exercise can promote myelin repair and coordinate inflammation and proliferation are still uncertain. In this study, we conducted histological and biochemical assays of cortical lysates after behavioral testing to detect pathological changes, myelin sheath thickness, and mRNA and protein levels. It is notable that D-galactose model mice exhibited elevated miRNA-34a levels, overactive astrocytes, decreased myelin staining scores, increased apoptosis, and decreased synaptic plasticity in the brain. Significantly, after eight weeks of exercise, we observed improvements in LFB scores, NeuN( +) neuron counts, and myelin basic protein (MBP) expression. Additionally, exercise promoted the expression of oligodendrocyte markers Olig2 and PDFGR-α associated with brain proliferation, and improved spatial cognitive function. Furthermore, it decreased the inflammation caused by astrocyte secretions (TNF-α, Cox-2, CXCL2). Interestingly, we also observed downregulation of miR-34a and activation of the TAN1/PI3K/CREB signaling pathway. Our data shed light on a previously unsuspected mechanism by which exercise reduces miR-34a levels and protects neuronal function and survival by preventing excessive demyelination and inflammatory infiltration in the CNS.


Assuntos
Doença de Alzheimer , MicroRNAs , Animais , Camundongos , Doença de Alzheimer/metabolismo , Astrócitos/metabolismo , Inflamação/metabolismo , MicroRNAs/genética , MicroRNAs/metabolismo , Bainha de Mielina/metabolismo , Doenças Neuroinflamatórias , Oligodendroglia/metabolismo
5.
Crit Rev Food Sci Nutr ; : 1-37, 2024 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-38794836

RESUMO

Neurodegenerative diseases encompass a wide range of debilitating and incurable brain disorders characterized by the progressive deterioration of the nervous system's structure and function. Isoflavones, which are naturally occurring polyphenolic phytochemicals, have been found to regulate various cellular signaling pathways associated with the nervous system. The main objective of this comprehensive review is to explore the neuroprotective effects of isoflavones, elucidate the underlying mechanisms, and assess their potential for treating neurodegenerative disorders. Relevant data regarding isoflavones and their impact on neurodegenerative diseases were gathered from multiple library databases and electronic sources, including PubMed, Google Scholar, Web of Science, and Science Direct. Numerous isoflavones, including genistein, daidzein, biochanin A, and formononetin, have exhibited potent neuroprotective properties against various neurodegenerative diseases. These compounds have been found to modulate neurotransmitters, which in turn contributes to their ability to protect against neurodegeneration. Both in vitro and in vivo experimental studies have provided evidence of their neuroprotection mechanisms, which involve interactions with estrogenic receptors, antioxidant effects, anti-inflammatory properties, anti-apoptotic activity, and modulation of neural plasticity. This review aims to provide current insights into the neuroprotective characteristics of isoflavones and shed light on their potential therapeutic applications in future clinical scenarios.

6.
Plant Cell Environ ; 46(11): 3628-3643, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37485926

RESUMO

The developmental process of spike is critical for spike fertility through affecting floret primordia fate in wheat; however, the genetic regulation of this dynamic and complex developmental process remains unclear. Here, we conducted a high temporal-resolution analysis of spike transcriptomes and monitored the number and morphology of floret primordia within spike. The development of all floret primordia in a spike was clearly separated into three distinct phases: differentiation, pre-dimorphism and dimorphism. Notably, we identified that floret primordia with meiosis ability at the pre-dimorphism phase usually develop into fertile floret primordia in the next dimorphism phase. Compared to control, increasing plant space treatment achieved the maximum increasement range (i.e., 50%) in number of fertile florets by accelerating spike development. The process of spike fertility improvement was directed by a continuous and dynamic regulatory network involved in transcription factor and genes interaction. This was based on the coordination of genes related to heat shock protein and jasmonic acid biosynthesis during differentiation phase, and genes related to lignin, anthocyanin and chlorophyll biosynthesis during dimorphism phase. The multi-dimensional association with high temporal-resolution approach reported here allows rapid identification of genetic resource for future breeding studies to realise the maximum spike fertility potential in more cereal crops.


Assuntos
Flores , Triticum , Flores/fisiologia , Redes Reguladoras de Genes , Grão Comestível/genética , Fertilidade/genética
7.
Altern Ther Health Med ; 29(5): 54-64, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37052968

RESUMO

Context: Danggui Buxue Tang (DBT) is a classical Chinese medicine that practitioners have used for thousands of years. Historically, those practitioners have used 16 prescriptions of DBT but currently are using only three prescriptions. Objective: The review intended to summarize pharmacological profiles of DBT and also clarify the major active chemicals found within it to provide a better understanding of the significance of DBT clinically. Design: The research team performed a narrative review by searching Pubmed databases. The search used the keywords Danggui Buxue Tang, bioactive chemcials, pharmacological functions. Setting: The databases setting were done by Gong Guowei and Zhou Xuan in the Zunyi Medical University, Zhuhai campus. Results: There are multiple results related to the crude fractions isolated from Danggui Buxue Tang, and also included the clinical trails. Conclusions: Thousands of years of clinical experience have ensured the efficacy of TCM treatments, which can determine the direction of basic research. That research can modify formulas at the molecular level to improve targeting and specificity in the treatment of specific diseases. As a result, the discovery and identification of new compounds within the herbal complex can provide useful research ideas and ensure the viability of new drug development.


Assuntos
Medicamentos de Ervas Chinesas , Humanos , Medicamentos de Ervas Chinesas/farmacologia , Medicamentos de Ervas Chinesas/uso terapêutico
8.
J Bacteriol ; 201(19)2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31262840

RESUMO

Pseudomonas stutzeri A1501 is a versatile nitrogen-fixing bacterium capable of living in diverse environments and coping with various oxidative stresses. NfiS, a regulatory noncoding RNA (ncRNA) involved in the control of nitrogen fixation in A1501, was previously shown to be required for optimal resistance to H2O2; however, the precise role of NfiS and the target genes involved in the oxidative stress response is entirely unknown. In this work, we systematically investigated the NfiS-based mechanisms underlying the response of this bacterium to H2O2 at the cellular and molecular levels. A mutant strain carrying a deletion of nfiS showed significant downregulation of oxidative stress response genes, especially katB, a catalase gene, and oxyR, an essential regulator for transcription of catalase genes. Secondary structure prediction revealed two binding sites in NfiS for katB mRNA. Complementation experiments using truncated nfiS genes showed that each of two sites is functional, but not sufficient, for NfiS-mediated regulation of oxidative stress resistance and nitrogenase activities. Microscale thermophoresis assays further indicated direct base pairing between katB mRNA and NfiS at both sites 1 and 2, thus enhancing the half-life of the transcript. We also demonstrated that katB expression is dependent on OxyR and that both OxyR and KatB are essential for optimal oxidative stress resistance and nitrogenase activities. H2O2 at low concentrations was detoxified by KatB, leaving O2 as a by-product to support nitrogen fixation under O2-insufficient conditions. Moreover, our data suggest that the direct interaction between NfiS and katB mRNA is a conserved and widespread mechanism among P. stutzeri strains.IMPORTANCE Protection against oxygen damage is crucial for survival of nitrogen-fixing bacteria due to the extreme oxygen sensitivity of nitrogenase. This work exemplifies how the small ncRNA NfiS coordinates oxidative stress response and nitrogen fixation via base pairing with katB mRNA and nifK mRNA. Hence, NfiS acts as a molecular link to coordinate the expression of genes involved in oxidative stress response and nitrogen fixation. Our study provides the first insight into the biological functions of NfiS in oxidative stress regulation and adds a new regulation level to the mechanisms that contribute to the oxygen protection of the MoFe nitrogenase.


Assuntos
Catalase/genética , Peróxido de Hidrogênio/farmacologia , Pseudomonas stutzeri/genética , RNA não Traduzido/genética , Proteínas de Bactérias/genética , Pareamento de Bases , Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos , Mutação , Fixação de Nitrogênio/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Pseudomonas stutzeri/efeitos dos fármacos , RNA Bacteriano/genética , Proteínas Repressoras/genética
9.
J Transl Med ; 17(1): 278, 2019 08 22.
Artigo em Inglês | MEDLINE | ID: mdl-31438987

RESUMO

BACKGROUND: Calcium oxalate (CaOx), the major constituent of most kidney stones, induces inflammatory infiltration and injures renal tubular cells. However, the role of γδT cells in CaOx-mediated kidney injury remains unclear. Therefore, this study investigated the distribution of intrarenal γδT cells and T cell receptor δ (TCRδ) immune repertoires in response to interactions with CaOx crystals. METHODS: CaOx crystal mouse model was established by glyoxylate injection. Flow cytometer was used to analyze the expression of CD69 and IL-17 from intrarenal γδT cells. Furthermore, TCR immune repertoire sequencing (IR-Seq) was used to monitor the profile of the TCRδ immune repertoire. RESULTS: Our results indicated that CaOx crystals lead to obvious increases in the expression and activation of intrarenal γδT cells. In TCRδ immune repertoire, the majority of V/J gene and V-J/V-D-J combination segments, barring individual exceptions, were similar between kidneys with CaOx formation and control kidneys. Impressively, high complementarity determining region 3 (CDR3) diversity was observed in response to CaOx crystal formation along with distinct CDR3 distribution and abundance. CONCLUSION: Our work suggests the presence of aberrant γδT cell activation and reconstitution of the TCRδ immune repertoire in response to CaOx crystal deposition.


Assuntos
Oxalato de Cálcio/efeitos adversos , Rim/lesões , Receptores de Antígenos de Linfócitos T gama-delta/imunologia , Animais , Células Clonais , Cristalização , Rim/patologia , Masculino , Camundongos Endogâmicos C57BL
10.
Appl Environ Microbiol ; 85(14)2019 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-31076427

RESUMO

Expression of nitrogenase genes (nifHDK) is strictly regulated at both transcriptional and posttranscriptional levels. Efficient nitrogenase activity requires maintaining sufficient levels of nif mRNAs, yet the underlying mechanism is not fully understood due to its complexity. We have previously shown that a novel regulatory noncoding RNA (ncRNA), NfiS, optimizes nitrogen fixation through targeting nifK mRNA in Pseudomonas stutzeri A1501. Here, we report the identification and characterization of a second ncRNA inducible under nitrogen fixation conditions (nitrogen-free and microaerobic conditions), termed NfiR (for nitrogen fixation condition-inducible ncRNA), the expression of which is dependent on two global regulators, NtrC and Hfq. Comparative phenotypic and proteomic analyses of an nfiR mutant identify a role of NfiR in regulating the expression of nitrogenase genes. Further microscale thermophoresis and genetic complementation showed that an 11-nucleotide (nt) sequence in the stem-loop structure of NfiR (nucleotides 12 to 22) pairs with its counterpart in the coding region of nifD mRNA (nucleotides 1194 to 1207) by eight nucleotides. Significantly, deletion of nfiR caused a 60% reduction of nitrogenase activity, and the half-life of nifD mRNA was reduced from 20 min for the wild type to 15 min for the ΔnfiR mutant. With regard to nitrogenase activity and stability of the nifD and nifK transcripts, phenotypes were more severe for the double deletion mutant lacking nfiR and nfiS, suggesting that NfiR, in concert with NfiS, optimizes nitrogenase production at the posttranscriptional level.IMPORTANCE Biological nitrogen fixation is an energy-expensive process requiring the hydrolysis of 16 ATPs. Consequently, the expression of nif genes is highly regulated at both transcriptional and posttranscriptional levels through complex regulatory networks. Global regulation involves a number of regulatory proteins, such as the nif-specific activator NifA and the global nitrogen regulator NtrC, as well as various regulatory ncRNAs. We show that the two P. stutzeri ncRNAs, namely NfiS and NfiR (for nitrogen fixation condition-inducible ncRNA), optimize nitrogen fixation and environmental stress responses. NfiS and NfiR respond differently to various environmental signals and differ in their secondary structures. In addition, the two ncRNAs target the mRNAs of nifK and nifD, respectively. Such ncRNA-based posttranscriptional regulation of nitrogenase expression might be an evolved survival strategy, particularly in nitrogen-limiting environments. This study not only highlights the significant roles of regulatory ncRNAs in the coordination and fine tuning of various physiological processes but also provides a new paradigm for posttranscriptional regulation in nitrogen-fixing bacteria.


Assuntos
Proteínas de Bactérias/genética , Regulação Bacteriana da Expressão Gênica , Nitrogenase/genética , Pseudomonas stutzeri/genética , RNA não Traduzido/genética , Proteínas de Bactérias/metabolismo , Nitrogenase/metabolismo , Pseudomonas stutzeri/metabolismo , RNA não Traduzido/metabolismo
11.
Chin J Cancer Res ; 29(3): 196-203, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28729770

RESUMO

OBJECTIVE: Detection rate and isolation yield of circulating tumor cell (CTC) are low in squamous cell carcinoma of head and neck (SCCHN) with in vitro approaches due to limited sample volumes. In this study, we applied the CellCollector to capture CTC in vivo from peripheral blood. METHODS: In total, the study included 22 cases with 37 times of detection. All of the patients were newly diagnosed with locally advanced or metastatic SCCHN, including laryngocarcinoma (40.9%, 9/22) and hypopharyngeal carcinoma (59.1%, 13/22). All patients received CTC analysis before treatment. Three patients received induction chemotherapy. Sixteen patients received surgical therapy, of which 13 patients received postoperative detection. Two patients received both induction chemotherapy and surgery treatment. Patients underwent two successive CellCollector applications 24 h before and 7 d after surgical therapy. Nine healthy volunteers were enrolled as the control group. Epidermal growth factor receptor variant type III (EGFRVIII) expression was analyzed with fluorescent dye labeled antibody. RESULTS: With CellCollector isolation, 72.7% (16/22) of the patients were positive for ≥1 CTC (CTC; range, 1-17 cells) before treatments and 46.7% (7/15) of patients were CTC positive for ≥1 CTC (CTC; range, 1-29 cells) after surgical therapy. Moreover, the detection rate of CellCollector (82.4%, 14/17; CTC count range, 0-17) in advanced SCCHN (stage III-IV) was much higher than that in early stages (stage I-II, 40.0%, 2/5; CTC count range, 0-2) (P<0.05). EGFRVIII expression of CTC was also analyzed with fluorescence staining. One CTCEGFRVIII-positive patient was detected from six CTC-positive patients, and the positive expression of EGFRVIII was also found in the tumor tissue of this patient. CONCLUSIONS: In vivo detection of CTCs had high sensitivity in SCCHN, which might improve CTC application in clinic.

12.
Cell Physiol Biochem ; 35(6): 2349-59, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25896320

RESUMO

BACKGROUND/AIMS: Obesity-associated fatty liver disease affects millions of individuals. This study aimed to evaluate the therapeutic effects of baicalin to treat obesity and fatty liver in high fat diet-induced obese mice, and to study the potential molecular mechanisms. METHODS: High fat diet-induced obese animals were treated with different doses of baicalin (100, 200 and 400 mg/kg/d). Whole body, fat pad and liver were weighed. Hyperlipidemia, liver steatosis, liver function, and hepatic Ca(2+)/CaM-dependent protein kinase kinase ß (CaMKKß) / AMP-activated protein kinase (AMPK) / acetyl-CoA carboxylase (ACC) were further evaluated. RESULTS: Baicalin significantly decreased liver, epididymal fat and body weights in high fat diet-fed mice, which were associated with decreased serum levels of triglycerides, total cholesterol, LDL, alanine transaminase and aspartate transaminase, but increased serum HDL level. Pathological analysis revealed baicalin dose-dependently decreased the degree of hepatic steatosis, with predominantly diminished macrovesicular steatosis at lower dose but both macrovesicular and microvesicular steatoses at higher dose of baicalin. Baicalin dose-dependently inhibited hepatic CaMKKß/AMPK/ACC pathway. CONCLUSION: These data suggest that baicalin up to 400 mg/kg/d is safe and able to decrease the degree of obesity and fatty liver diseases. Hepatic CaMKKß/AMPK/ACC pathway may mediate the therapeutic effects of baicalin in high fat diet animal model.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Acetil-CoA Carboxilase/metabolismo , Quinase da Proteína Quinase Dependente de Cálcio-Calmodulina/metabolismo , Dieta Hiperlipídica/efeitos adversos , Fígado Gorduroso/tratamento farmacológico , Flavonoides/farmacologia , Obesidade/tratamento farmacológico , Tecido Adiposo/efeitos dos fármacos , Tecido Adiposo/metabolismo , Alanina Transaminase/sangue , Animais , Aspartato Aminotransferases/sangue , Peso Corporal/efeitos dos fármacos , Fígado Gorduroso/sangue , Fígado Gorduroso/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Obesos , Obesidade/sangue , Obesidade/metabolismo , Transdução de Sinais/efeitos dos fármacos , Triglicerídeos/sangue
13.
Int Immunopharmacol ; 132: 111959, 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38554442

RESUMO

Triple-negative breast cancer (TNBC) is a subtype of breast cancer that is difficult to treat due to a lack of targeted therapies. In this study, we aimed to investigate whether a natural flavonoid compound called ononin could be effective in treating TNBC by triggering ferroptosis in MDA-MB-231 and 4 T1 cell lines, and MDA-MB-231-xenograft nude mice model. Ononin inhibited TNBC through ferroptosis, which was determined by MTT assay, flow cytometry, RT-PCR, immunofluorescence, transmission electron microscopy, histological analysis, western blot and bioluminescence assay. Our results showed that treatment with ononin led to increased levels of malondialdehyde and reactive oxygen species and decreased activity of superoxide dismutase, which are indicatives of ferroptosis. We also found that ononin downregulated two key markers of ferroptosis, SLC7A11 and Nrf2, at both the transcriptional and translational level. Additionally, the administration of ononin resulted in a notable decrease in tumor size and weight in the mouse model. Furthermore, it was observed to enhance the rate of apoptosis in TNBC cells. Importantly, ononin did not induce any histological changes in the kidney, liver, and heart. Taken together, our findings suggest that ononin could be a promising therapeutic strategy for TNBC, and that it works by disrupting the Nrf2/SLC7A11 axis through ferroptosis. These results are encouraging and may lead to the development of new treatments for this challenging cancer subtype.


Assuntos
Ferroptose , Camundongos Nus , Fator 2 Relacionado a NF-E2 , Neoplasias de Mama Triplo Negativas , Ensaios Antitumorais Modelo de Xenoenxerto , Ferroptose/efeitos dos fármacos , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Neoplasias de Mama Triplo Negativas/patologia , Animais , Humanos , Feminino , Linhagem Celular Tumoral , Fator 2 Relacionado a NF-E2/metabolismo , Camundongos , Sistema y+ de Transporte de Aminoácidos/metabolismo , Sistema y+ de Transporte de Aminoácidos/genética , Camundongos Endogâmicos BALB C , Espécies Reativas de Oxigênio/metabolismo , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Apoptose/efeitos dos fármacos
14.
J Ethnopharmacol ; 323: 117655, 2024 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-38158099

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Danggui Buxue Tang (DBT) has been used for over 800 years to enhance Qi and nourish Blood, and it is particularly beneficial for cancer patients. Recent research has shown that combining DBT with chemotherapy agents leads to superior anti-cancer effects, thereby enhancing therapeutic efficacy. AIM OF THE STUDY: The aim of this study was to evaluate the effectiveness of a combination therapy involving doxorubicin (DOX) and Danggui Buxue Tang (DBT) in the treatment of triple-negative breast cancer (TNBC) and to elucidate the underlying mechanisms of action. MATERIALS AND METHODS: In vitro experiments were performed using MDA-MB-231 and 4T1 cells, while in vivo experiments were carried out using MDA-MB-231 xenograft mice. The therapeutic effects of the combination therapy were evaluated using various techniques, including MTT assay, colony formation assay, flow cytometry, transwell assay, immunofluorescence, transmission electron microscopy (TEM), histological analysis, western blotting, and bioluminescence assay. RESULTS: DBT was found to enhance DOX's anti-TNBC activity in vitro by promoting ferroptosis, as evidenced by the observed mitochondrial morphological changes using TEM. The combination therapy was also found to reduce the expression of Nrf2, HO-1, and GPX4, which are all targets for ferroptosis induction, while simultaneously increasing ROS production. Additionally, the combination therapy reduced nuclear accumulation and constitutive activation of Nrf2, which is a significant cause of chemotherapy resistance and promotes cancer growth. In vivo experiments using an MDA-MB-231 xenograft animal model revealed that the combination therapy significantly reduced tumor cell proliferation and accelerated TNBC deaths by modulating the Nrf2/HO-1/GPX4 axis, with no evidence of tissue abnormalities. Moreover, the combination therapy exhibited a liver protective effect, and administration of Fer-1 was able to reduce the ROS formation produced by the DBT + DOX combination therapy. CONCLUSION: This study provides evidence that the combination therapy of DOX and DBT has the potential to treat TNBC by promoting ferroptosis through the Nrf2/HO-1/GPX4 axis.


Assuntos
Medicamentos de Ervas Chinesas , Ferroptose , Neoplasias de Mama Triplo Negativas , Humanos , Camundongos , Animais , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Fator 2 Relacionado a NF-E2 , Espécies Reativas de Oxigênio , Doxorrubicina/farmacologia , Doxorrubicina/uso terapêutico , Modelos Animais de Doenças
15.
Gene ; 922: 148544, 2024 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-38734187

RESUMO

This study introduces an efficient RPA-PfAgo detection system for the MTHFR C677T polymorphism, proposing a potential strategy to simplify the genotyping process. By optimizing recombinase polymerase amplification (RPA) with Pyrococcus furiosus Argonaute (PfAgo) nucleases, we achieved DNA amplification at a constant temperature. The assay was fine-tuned through meticulous primer and guide DNA selection, with optimal conditions established at 2.0 µL of MgAc, a reaction temperature of 42 °C, and a 10-minute reaction time for RPA. Further optimization of the PfAgo cleavage assay revealed the ideal concentrations of MnCl2, guide DNA, molecular beacon probes, the PfAgo enzyme, and the RPA product to maximize sensitivity and specificity. Clinical validation of 20 samples showed 100% concordance with Sanger sequencing, confirming the method's precision. The RPA-PfAgo system is a promising tool for on-site genotyping, with broad applications in personalized medicine and disease prevention.


Assuntos
Técnicas de Genotipagem , Metilenotetra-Hidrofolato Redutase (NADPH2) , Humanos , Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , Técnicas de Genotipagem/métodos , Polimorfismo de Nucleotídeo Único , Pyrococcus furiosus/genética , Pyrococcus furiosus/enzimologia , Genótipo , Técnicas de Amplificação de Ácido Nucleico/métodos , Proteínas Argonautas/genética , Recombinases/metabolismo , Recombinases/genética
16.
Int J Food Microbiol ; 417: 110697, 2024 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-38642433

RESUMO

Foodborne illness caused by Salmonella spp. is one of the most prevalent public health problems globally, which have brought immeasurable economic burden and social impact to countries around the world. Neither current nucleic acid amplification detection method nor standard culture method (2-3 days) are suitable for field detection in areas with a heavy burden of Salmonella spp. Here, we developed a highly sensitive and accurate assay for Salmonella spp. detection in less than 40 min. Specifically, the invA gene of Salmonella spp. was amplified by recombinase polymerase amplification (RPA), followed by Pyrococcus furiosus Argonaute (PfAgo)-based target sequence cleavage, which could be observed by a fluorescence reader or the naked eye. The assay offered the lowest detectable concentration of 1.05 × 101 colony forming units/mL (CFU/mL). This assay had strong specificity and high sensitivity for the detection of Salmonella spp. in field samples, which indicated the feasibility of this assay.


Assuntos
Microbiologia de Alimentos , Técnicas de Amplificação de Ácido Nucleico , Pyrococcus furiosus , Salmonella , Pyrococcus furiosus/genética , Salmonella/genética , Salmonella/isolamento & purificação , Técnicas de Amplificação de Ácido Nucleico/métodos , Inocuidade dos Alimentos , Recombinases/metabolismo , Recombinases/genética , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Proteínas Argonautas/genética , Proteínas Argonautas/metabolismo , Sensibilidade e Especificidade , Contaminação de Alimentos/análise
17.
Curr Res Food Sci ; 8: 100681, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38304000

RESUMO

The crisp grass carp (CGC; Ctenopharyngodon idellus C. et V.), known for its unique texture and flavour, is a culinary delicacy whose quality is significantly influenced by thermal processing. This study employed 4D label-free proteomics and data mining techniques to investigate the proteomic changes in CGC muscle tissue induced by various heating temperatures. CGC samples were subjected to a series of heat treatments at increasing temperatures from 20 °C to 90 °C. Proteins were extracted, digested, and analysed using high-resolution mass spectrometry. The proteomic data were then subjected to extensive bioinformatics analysis, including GO and KEGG pathway enrichment. We identified a total of 1085 proteins, 516 of which were shared across all the temperature treatments, indicating a core proteome responsible for CGC textural properties. Differential expression analysis revealed temperature-dependent changes, with significant alterations observed at 90 °C, suggesting denaturation or aggregation of proteins at higher temperatures. Functional enrichment analysis indicated that proteins involved in amino acid metabolism, glutathione metabolism, and nucleotide metabolism were particularly affected by heat. Textural analysis correlated these proteomic changes with alterations in CGC quality attributes, pinpointing 70 °C as the optimum temperature for maintaining the desired texture. A strong positive correlation between specific upregulated proteins was identified, such as the tubulin alpha chain and collagen alpha-1(IV) chain, and the improved textural properties of CGC during thermal processing, suggesting their potential as the potential biomarkers. This study offers a comprehensive proteomic view of the thermal stability and functionality of CGC proteins, delivering invaluable insights for both the culinary processing and scientific management of CGC. Our findings not only deepen the understanding of the molecular mechanisms underpinning the textural alterations in CGC during thermal processing but also furnish practical insights for the aquaculture industry. These insights could be leveraged to optimize cooking techniques, thereby enhancing the quality and consumer appeal of CGC products.

18.
Artigo em Zh | MEDLINE | ID: mdl-37905489

RESUMO

This patient suffered from severe subglottic stenosis(grade Ⅳb). During partial cricotracheal resection, we cut through the cricothyroid membrane and the cricoid arch along the line from the lower edge of the thyroid cartilage to 5 mm of the inferior thyroid cartilage corner anteromedially. This can protect the cricothyroid joint, effectively protect the recurrent laryngeal nerve, and also support the airway. Strictly adhere to airway separation, avoid excessive separation of scars, and combine with reasonable postoperative management to achieve a safe extubation.


Assuntos
Laringoestenose , Laringe , Humanos , Constrição Patológica/cirurgia , Traqueia/cirurgia , Extubação , Laringoestenose/cirurgia , Laringe/cirurgia , Cartilagem Cricoide/cirurgia , Resultado do Tratamento
19.
J Pharm Biomed Anal ; 235: 115632, 2023 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-37573622

RESUMO

In this study, a novel genotyping point-of-care testing (POCT) rapid detection device, the locked nucleic acid (LNA)-amplification refractory mutation system (ARMS)-recombinase polymerase amplification (RPA)-GoldMag lateral flow assay (LFA) platform, was provided by mining and synthesis based on prior technology. Research methods based on system-integrated innovation and knowledge-integrated generation have become a new trend in technology development. Here, we exploit the combination of LNA-coupled ARMS-RPA and gold nanoparticle probe technology for detection signal amplification, thus pioneering a new tool for accurate, rapid, and cost-effective genotyping. We also performed SNP typing detection and clinical validation of this new assay platform using common glucose-6-phosphate dehydrogenase (G6PD) gene single nucleotide polymorphism (SNP) loci, and the results demonstrated the high sensitivity, specificity, stability, accuracy and feasibility of the LNA-ARMS-RPA-GoldMag lateral flow assay platform. It is hoped that this new technology will make a significant contribution to the field of POCT rapid diagnosis and aim to expand the application space, reflecting its clinical application value and development prospects.


Assuntos
Nanopartículas Metálicas , Recombinases , Recombinases/genética , Ouro , Sensibilidade e Especificidade , Testes Imediatos , Mutação
20.
Nat Protoc ; 18(4): 1260-1295, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36653528

RESUMO

Studying the dynamics of genome replication in mammalian cells has been historically challenging. To reveal the location of replication initiation and termination in the human genome, we developed Okazaki fragment sequencing (OK-seq), a quantitative approach based on the isolation and strand-specific sequencing of Okazaki fragments, the lagging strand replication intermediates. OK-seq quantitates the proportion of leftward- and rightward-oriented forks at every genomic locus and reveals the location and efficiency of replication initiation and termination events. Here we provide the detailed experimental procedures for performing OK-seq in unperturbed cultured human cells and budding yeast and the bioinformatics pipelines for data processing and computation of replication fork directionality. Furthermore, we present the analytical approach based on a hidden Markov model, which allows automated detection of ascending, descending and flat replication fork directionality segments revealing the zones of replication initiation, termination and unidirectional fork movement across the entire genome. These tools are essential for the accurate interpretation of human and yeast replication programs. The experiments and the data processing can be accomplished within six days. Besides revealing the genome replication program in fine detail, OK-seq has been instrumental in numerous studies unravelling mechanisms of genome stability, epigenome maintenance and genome evolution.


Assuntos
Replicação do DNA , DNA , Humanos , DNA/genética , Genômica , Biologia Computacional , Saccharomyces cerevisiae/genética
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