RESUMO
It is known that sialyllactose (SL) in mammalians is a major source of sialic acid (Sia), which can further form cytidine monophosphate sialic acid (CMP-Sia), and the final product is polysialic acid (polySia) using polysialyltransferases (polySTs) on the neural cell adhesion molecule (NCAM). This process is called NCAM polysialylation. The overexpression of polysialylation is strongly related to cancer cell migration, invasion, and metastasis. In order to inhibit the overexpression of polysialylation, in this study, SL was selected as an inhibitor to test whether polysialylation could be inhibited. Our results suggest that the interactions between the polysialyltransferase domain (PSTD) in polyST and CMP-Siaand the PSTD and polySia could be inhibited when the 3'-sialyllactose (3'-SL) or 6'-sialyllactose (6'-SL) concentration is about 0.5 mM or 6'-SL and 3 mM, respectively. The results also show that SLs (particularly for 3'-SL) are the ideal inhibitors compared with another two inhibitors, low-molecular-weight heparin (LMWH) and cytidine monophosphate (CMP), because 3'-SL can not only be used to inhibit NCAM polysialylation, but is also one of the best supplements for infant formula and the gut health system.
RESUMO
The stems and leaves of Panax notoginseng contain high saponins, but they are often discarded as agricultural waste. In this study, the predominant ginsenosides Rg1, Rc, and Rb2, presented in the stems and leaves of ginseng plants, were biotransformed into value-added rare ginsenosides F1, compound Mc1 (C-Mc1), and Rd2, respectively. A fungal strain YMS6 (Penicillium sp.) was screened from the soil as a biocatalyst with high selectivity for the deglycosylation of major ginsenosides. Under the optimal fermentation conditions, the yields of F1, C-Mc1, and Rd2 were 97.95, 68.64, and 79.58%, respectively. This study provides a new microbial resource for the selective conversion of protopanaxadiol-type and protopanaxatriol-type major saponins into rare ginsenosides via the whole-cell biotransformation and offers a solution for the better utilization of P. notoginseng waste.
Assuntos
Ginsenosídeos , Saponinas , Agricultura , BiotransformaçãoRESUMO
The expression of polysialic acid (polySia) on the neuronal cell adhesion molecule (NCAM) is called NCAM-polysialylation, which is strongly related to the migration and invasion of tumor cells and aggressive clinical status. Thus, it is important to select a proper drug to block tumor cell migration during clinical treatment. In this study, we proposed that lactoferrin (LFcinB11) may be a better candidate for inhibiting NCAM polysialylation when compared with CMP and low-molecular-weight heparin (LMWH), which were determined based on our NMR studies. Furthermore, neutrophil extracellular traps (NETs) represent the most dramatic stage in the cell death process, and the release of NETs is related to the pathogenesis of autoimmune and inflammatory disorders, with proposed involvement in glomerulonephritis, chronic lung disease, sepsis, and vascular disorders. In this study, the molecular mechanisms involved in the inhibition of NET release using LFcinB11 as an inhibitor were also determined. Based on these results, LFcinB11 is proposed as being a bifunctional inhibitor for inhibiting both NCAM polysialylation and the release of NETs.
Assuntos
Armadilhas Extracelulares , Lactoferrina , Moléculas de Adesão de Célula Nervosa , Ácidos Siálicos , Lactoferrina/farmacologia , Lactoferrina/metabolismo , Humanos , Armadilhas Extracelulares/metabolismo , Armadilhas Extracelulares/efeitos dos fármacos , Moléculas de Adesão de Célula Nervosa/metabolismo , Ácidos Siálicos/metabolismo , Neutrófilos/metabolismo , Neutrófilos/efeitos dos fármacos , Heparina de Baixo Peso Molecular/farmacologiaRESUMO
BACKGROUND: Resveratrol is a commercially available stilbenoid widely used as dietary supplements, functional food ingredients, and cosmetic ingredients due to its diverse physiological activities. The production of resveratrol in microorganisms provides an ideal source that reduces the cost of resveratrol, but the titer in Saccharomyces cerevisiae was still much lower than that in other hosts. RESULTS: To achieve enhanced production of resveratrol in S. cerevisiae, we constructed a biosynthetic pathway via combining phenylalanine and tyrosine pathways by introducing a bi-functional phenylalanine/tyrosine ammonia lyase from Rhodotorula toruloides. The combination of phenylalanine pathway with tyrosine pathway led to a 462% improvement of resveratrol production in yeast extract peptone dextrose (YPD) medium with 4% glucose, suggesting an alternative strategy for producing p-coumaric acid-derived compounds. Then the strains were further modified by integrating multi-copy biosynthetic pathway genes, improving metabolic flux to aromatic amino acids and malonyl-CoA, and deleting by-pathway genes, which resulted in 1155.0 mg/L resveratrol in shake flasks when cultured in YPD medium. Finally, a non-auxotrophic strain was tailored for resveratrol production in minimal medium without exogenous amino acid addition, and the highest resveratrol titer (4.1 g/L) ever reported was achieved in S. cerevisiae to our knowledge. CONCLUSIONS: This study demonstrates the advantage of employing a bi-functional phenylalanine/tyrosine ammonia lyase in the biosynthetic pathway of resveratrol, suggesting an effective alternative in the production of p-coumaric acid-derived compounds. Moreover, the enhanced production of resveratrol in S. cerevisiae lays a foundation for constructing cell factories for various stilbenoids.
Assuntos
Saccharomyces cerevisiae , Tirosina , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Resveratrol/metabolismo , Tirosina/metabolismo , Fenilalanina/metabolismo , Fenilalanina Amônia-Liase/genética , Fenilalanina Amônia-Liase/metabolismo , Engenharia Metabólica/métodosRESUMO
BACKGROUND: Ginsenosides are Panax plant-derived triterpenoid with wide applications in cardiovascular protection and immunity-boosting. However, the saponins content of Panax plants is fairly low, making it time-consuming and unsustainable by direct extraction. Protopanaxadiol (PPD) is a common precursor of dammarane-type saponins, and its sufficient supply is necessary for the efficient synthesis of ginsenoside. RESULTS: In this study, a combinational strategy was used for the construction of an efficient yeast cell factory for PPD production. Firstly, a PPD-producing strain was successfully constructed by modular engineering in Saccharomyces cerevisiae BY4742 at the multi-copy sites. Then, the INO2 gene, encoding a transcriptional activator of the phospholipid biosynthesis, was fine-tuned to promote the endoplasmic reticulum (ER) proliferation and improve the catalytic efficiency of ER-localized enzymes. To increase the metabolic flux of PPD, dynamic control, based on a carbon-source regulated promoter PHXT1, was introduced to repress the competition of sterols. Furthermore, the global transcription factor UPC2-1 was introduced to sterol homeostasis and up-regulate the MVA pathway, and the resulting strain BY-V achieved a PPD production of 78.13 ± 0.38 mg/g DCW (563.60 ± 1.65 mg/L). Finally, sugarcane molasses was used as an inexpensive substrate for the first time in PPD synthesis. The PPD titers reached 1.55 ± 0.02 and 15.88 ± 0.65 g/L in shake flasks and a 5-L bioreactor, respectively. To the best of our knowledge, these results were new records on PPD production. CONCLUSION: The high-level of PPD production in this study and the successful comprehensive utilization of low-cost carbon source -sugarcane molassesindicate that the constructed yeast cell factory is an excellent candidate strain for the production of high-value-added PPD and its derivativeswith great industrial potential.
Assuntos
Ginsenosídeos , Saccharum , Saponinas , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Saccharum/genética , Saccharum/metabolismo , Engenharia Metabólica/métodos , Melaço , Saponinas/metabolismo , Carbono/metabolismoRESUMO
Mechanisms for high L-lactic acid production remain unclear in many bacteria. Lactobacillus rhamnosus SCT-10-10-60 was previously obtained from L. rhamnosus ATCC 11443 via mutagenesis and showed improved L-lactic acid production. In this study, the genomes of strains SCT-10-10-60 and ATCC 11443 were sequenced. Both genomes are a circular chromosome, 2.99 Mb in length with a GC content of approximately 46.8%. Eight split genes were identified in strain SCT-10-10-60, including two LytR family transcriptional regulators, two Rex redox-sensing transcriptional repressors, and four ABC transporters. In total, 60 significantly up-regulated genes (log2fold-change ≥ 2) and 39 significantly down-regulated genes (log2fold-change ≤ - 2) were identified by a transcriptome comparison between strains SCT-10-10-60 and ATCC 11443. KEGG pathway enrichment analysis revealed that "pyruvate metabolism" was significantly different (P < 0.05) between the two strains. The split genes and the differentially expressed genes involved in the "pyruvate metabolism" pathway are probably responsible for the increased L-lactic acid production by SCT-10-10-60. The genome and transcriptome sequencing information and comparison of SCT-10-10-60 with ATCC 11443 provide insights into the anabolism of L-lactic acid and a reference for improving L-lactic acid production using genetic engineering.
Assuntos
Genômica , Ácido Láctico/biossíntese , Lacticaseibacillus rhamnosus/genética , Transcriptoma/genética , Regulação Bacteriana da Expressão Gênica , Genoma Bacteriano , Lacticaseibacillus rhamnosus/metabolismo , Engenharia Metabólica , Mutação , Ácido Pirúvico/metabolismoRESUMO
UNLABELLED: A better understanding of hepatocyte senescence could be used to treat age-dependent disease processes of the liver. Whether continuously proliferating hepatocytes could avoid or reverse senescence has not yet been fully elucidated. We confirmed that the livers of aged mice accumulated senescent and polyploid hepatocytes, which is associated with accumulation of DNA damage and activation of p53-p21 and p16(ink4a)-pRB pathways. Induction of multiple rounds continuous cell division is hard to apply in any animal model. Taking advantage of serial hepatocyte transplantation assays in the fumarylacetoacetate hydrolase-deficient (Fah(-/-)) mouse, we studied the senescence of hepatocytes that had undergone continuous cell proliferation over a long time period, up to 12 rounds of serial transplantations. We demonstrated that the continuously proliferating hepatocytes avoided senescence and always maintained a youthful state. The reactivation of telomerase in hepatocytes after serial transplantation correlated with reversal of senescence. Moreover, senescent hepatocytes harvested from aged mice became rejuvenated upon serial transplantation, with full restoration of proliferative capacity. The same findings were also true for human hepatocytes. After serial transplantation, the high initial proportion of octoploid hepatocytes decreased to match the low level of youthful liver. CONCLUSION: These findings suggest that the hepatocyte "ploidy conveyer" is regulated differently during aging and regeneration. The findings of reversal of hepatocyte senescence could enable future studies on liver aging and cell therapy.
Assuntos
Proliferação de Células , Senescência Celular/fisiologia , Hepatócitos/citologia , Hepatócitos/transplante , Regeneração Hepática/fisiologia , Animais , Inibidor p16 de Quinase Dependente de Ciclina/metabolismo , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Citometria de Fluxo , Hepatócitos/fisiologia , Hidrolases/genética , Óperon Lac , Fígado/citologia , Fígado/fisiologia , Masculino , Camundongos , Camundongos da Linhagem 129 , Camundongos Knockout , Poliploidia , Telomerase/metabolismo , Proteína Supressora de Tumor p53/metabolismoRESUMO
Panax notoginseng (Burk.) F.H. Chen is a traditional medicinal herb known as Sanqi or Tianqi in Asia and is commonly used worldwide. It is one of the main raw ingredients of Yunnan Baiyao, Fu fang dan shen di wan, and San qi shang yao pian. It is also a source of cardiotonic pill used to treat cardiovascular diseases in China, Korea, and Russia. Approximately 270 Panax notoginseng saponins have been isolated and identified as the major active components. Although the absorption and bioavailability of saponins are predominantly dependent on the gastrointestinal biotransformation capacity of an individual, minor saponins are better absorbed into the bloodstream and act as active substances than major saponins. Notably, minor saponins are absent or are present in minimal quantities under natural conditions. In this review, we focus on the strategies for the enrichment and production of minor saponins in P. notoginseng using physical, chemical, enzyme catalytic, and microbial methods. Moreover, pharmacological studies on minor saponins derived from P. notoginseng over the last decade are discussed. This review serves as a meaningful resource and guide, offering scholarly references for delving deeper into the exploration of the minor saponins in P. notoginseng.
Assuntos
Medicamentos de Ervas Chinesas , Panax notoginseng , Saponinas , Saponinas/química , Panax notoginseng/química , Medicamentos de Ervas Chinesas/química , Medicamentos de Ervas Chinesas/farmacologia , Humanos , Estrutura MolecularRESUMO
Mogrosides, which have various pharmacological activities, are mainly extracted from Siraitia grosvenorii (Luo Han Guo) and are widely used as natural zero-calorie sweeteners. Unfortunately, the difficult cultivation and long maturation time of Luo Han Guo have contributed to a shortage of mogrosides. To overcome this obstacle, we developed a highly efficient biosynthetic method using engineered Escherichia coli to synthesize sweet mogrosides from bitter mogrosides. Three UDP-glycosyltransferase (UGT) genes with primary/branched glycosylation catalytic activity at the C3/C24 sites of mogrosides were screened and tested. Mutant M3, which could catalyze the glycosylation of nine types of mogrosides, was obtained through enhanced catalytic activity. This improvement in ß-(1,6)-glycosidic bond formation was achieved through single nucleotide polymorphisms and direct evolution, guided by 3D structural analysis. A new multienzyme system combining three UGTs and UDP-glucose (UDPG) regeneration was developed to avoid the use of expensive UDPG. Finally, the content of sweet mogrosides in the immature Luo Han Guo extract increased significantly from 57% to 95%. This study not only established a new multienzyme system for the highly efficient production of sweet mogrosides from immature Luo Han Guo but also provided a guideline for the high-value utilization of rich bitter mogrosides from agricultural waste and residues.
Assuntos
Cucurbitaceae , Escherichia coli , Glicosiltransferases , Edulcorantes , Escherichia coli/genética , Escherichia coli/metabolismo , Glicosilação , Edulcorantes/metabolismo , Edulcorantes/química , Glicosiltransferases/genética , Glicosiltransferases/metabolismo , Cucurbitaceae/metabolismo , Cucurbitaceae/genética , Engenharia Metabólica , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Proteínas de Plantas/química , Triterpenos/metabolismo , Triterpenos/químicaRESUMO
To identify Salvia shandongensis and its relatives at molecular level, the psbA-trnH intergenic region of three species including Salvia shandongensis, Salvia miltiorrhiza and S. miltiorrhiza f. alba were amplified and sequenced. Sequences were assembled with CodonCode Aligner. The K2P genetic distances between Salvia shandongensis and its relatives were calculated and UPGMA tree was performed by MEGA5.0. The results indicated that the lengths of psbA-trnH regions of Salvia shandongensis were about 391 bp, while the lengths of psbA-trnH regions of Salvia miltiorrhiza and S. miltiorrhiza f. alba were about 386 bp. The psbA-trnH sequences showed considerable variations between species and thus were revealed as a promising candidate for barcoding of Salvia shandongensis and its relatives. The intra-specific genetic distances of Salvia shandongensis were 0, while the intra-specific genetic distances of Salvia miltiorrhiza and S. miltiorrhiza f. alba were 0.002 and 0.001 respectively. Additionally, the genetic distance of Salvia shandongensis and Salvia miltiorrhiza ranged from 0.034 to 0.04, and the genetic distance of Salvia shandongensis and S. miltiorrhiza f. alba ranged from 0.005 to 0.008, the intra-specific genetic distances of Salvia shandongensis were much smaller than that of Salvia miltiorrhiza and S. miltiorrhiza f. alba; clustering results showed that there were obvious differences between Salvia shandongensis, Salvia miltiorrhiza and S. miltiorrhiza f. alba, which was consistent with morphological characteristics. This study not only firstly provides the scientific basis for establishing the taxonomy position in molecular level and revealing their genetic relationships of S. shandongensis, S. miltiorrhiza and S. miltiorrhiza f. alba; but also provides DNA molecular identification scientific basis for the development of new medicinal plant resources of Salvia shandongensis. Our results suggest that the psbA-trnH intergenic spacer region can be used as a barcoding to identify Salvia shandongensis, Salvia miltiorrhiza and S. miltiorrhiza f. alba.
Assuntos
DNA Intergênico/genética , DNA de Plantas/genética , Plantas Medicinais/genética , Plastídeos/genética , Salvia/genética , Sequência de Bases , Código de Barras de DNA Taxonômico , Variação Genética , Filogenia , Plantas Medicinais/classificação , Salvia/classificação , Análise de Sequência de DNA , Especificidade da EspécieRESUMO
OBJECTIVE: Depression is accompanied by abnormalities in large-scale functional brain networks. This paper combined static and dynamic methods to analyze the abnormal topology and changes of functional connectivity network (FCN) of depression. METHODS: We collected resting-state EEG recordings from 27 depressed subjects and 28 normal subjects, then obtained 68 regions of interests (ROIs) by source localization. We took ROIs as the nodes and correlations as the edges to build FCNs and analyzed static network based on graph theory. We used a sliding window method followed by k-means clustering, states analyses and trend analysis of network metrics over time to study dynamic connectivity. RESULTS: The clustering coefficient (CC) and local efficiency in depression were increased, the characteristic path length and global efficiency were decreased, and local metrics had different manifestations in different resting state networks (RSNs); Depression had reduced connectivity in most RSNs, but increased connectivity in the default mode network, and there was a decoupling phenomenon between different RSNs; Depressed patients spent more time in sparsely connected states, their FCN's flexibility was less than normal subjects; The trend of CC over time was opposite between two groups. Most metrics in normal showed a relatively stronger correlation with time. SIGNIFICANCE: Our research may provide a deeper understanding of neurophysiological mechanisms of depression and new biomarkers for clinical diagnosis of depression.
Assuntos
Mapeamento Encefálico , Depressão , Humanos , Mapeamento Encefálico/métodos , Imageamento por Ressonância Magnética/métodos , Encéfalo/fisiologia , EletroencefalografiaRESUMO
Acetoin is an important four-carbon platform chemical with versatile applications. Optically pure (R)-acetoin is more valuable than the racemate as it can be applied in the asymmetric synthesis of optically active α-hydroxy ketone derivatives, pharmaceuticals, and liquid crystal composites. As a cytotoxic solvent, acetoin at high concentrations severely limits culture performance and impedes the acetoin yield of cell factories. In this study, putative genes that may improve the resistance to acetoin for Escherichia coli were screened. To obtain a high-producing strain, the identified acetoin-resistance gene was overexpressed, and the synthetic pathway of (R)-acetoin was strengthened by optimizing the copy number of the key genes. The engineered E. coli strain GXASR-49RSF produced 81.62 g/L (R)-acetoin with an enantiomeric purity of 96.5% in the fed-batch fermentation using non-food raw materials in a 3-L fermenter. Combining the systematic approach developed in this study with the use of low-cost feedstock showed great potential for (R)-acetoin production via this cost-effective biotechnological process.
RESUMO
Sclareol glycol is a key starting material with significant market interest for synthesizing high-value ambroxide, a sustainable substitute for ambergris in high-end fragrances. Sclareol glycol can be obtained by biotransformation of sclareol, a labdane-type diterpene, using Hyphozyma roseonigra. However, the pathway and mechanism of sclareol glycol biosynthesis remain unclear. In this study, the dynamic time course of sclareol biotransformation was explored by resting cell assays and several intermediates produced during biotransformation were detected. The results show that (1) sclareol glycol and sclareolide are not interconverted and are potentially synthesized via different metabolic pathways and (2) several putative intermediates resulting from biotransformation are featured with a labdane carbon backbone, including isomerized and oxidized analogues. A plausible transformation pathway of sclareol in H. roseonigra was proposed based on detected metabolites. This study sheds light on the biosynthetic mechanism of sclareol glycol and paves a way for the future biotechnological production of this promising compound.
Assuntos
Ascomicetos , Diterpenos , Ascomicetos/metabolismo , Biotransformação , Carbono/metabolismo , Diterpenos/metabolismoRESUMO
RATIONALE/IMPORTANCE: Researches have highlighted communication deficits between resting-state brain networks in major depressive disorder (MDD), as reflected in abnormal functional connectivity (FC). However, it is unclear whether impaired FC is associated with MDD pathology or is simply incidental to MDD symptoms. Moreover, there is no generalized theory to analyze the impact of treatment modalities on MDD. OBJECTIVES: To address the issues, we conducted a systematic review of 49 eligible papers to provide insight into the pathological mechanisms of MDD patients by summarizing resting-state FC alterations involving mood and cognitive abnormalities and the effects of medications on them. RESULTS: Mood disorders in MDD were characterized by abnormal FC between the amygdala, insula, anterior cingulate cortex (ACC), and prefrontal cortex (PFC). Cognitive impairment manifests as deficits in executive function, attention, memory, and rumination, primarily modulated by dysfunction between the fronto-parietal network and default mode network. Especially, we proposed the set of core abnormal FC (CA-FC) contributing to mood and cognitive impairment in MDD, currently including ACC-left precuneus/amygdala, rostral ACC-left dorsolateral PFC, left subgenual ACC-left cerebellar, left PFC- anterior subcallosal, and left precuneus-left pulvinar. After treatment, patients with normalized CA-FC showed remission of depressive symptoms. CONCLUSIONS: We propose a CA-FC set for possible causative principle of MDD, which unifies the FC results from specific, difficult-to-analyze conditions into one outcome set for screening. Furthermore, CA-FC varies from person to person, and the low success rate of a single treatment may be due to the inability to cover too many CA-FC.
Assuntos
Transtorno Depressivo Maior , Antidepressivos/uso terapêutico , Encéfalo/diagnóstico por imagem , Mapeamento Encefálico , Transtorno Depressivo Maior/diagnóstico por imagem , Transtorno Depressivo Maior/tratamento farmacológico , Giro do Cíngulo , Humanos , Imageamento por Ressonância MagnéticaRESUMO
UDP-glycosyltransferase (UGT)-mediated glycosylation is a common modification in triterpene saponins, which exhibit a wide range of bioactivities and important pharmacological effects. However, few UGTs involved in saponin biosynthesis have been identified, limiting the biosynthesis of saponins. In this study, an efficient heterologous expression system was established for evaluating the UGT-mediated glycosylation process of triterpene saponins. Six UGTs (UGTPn17, UGTPn42, UGTPn35, UGTPn87, UGTPn19, and UGTPn12) from Panax notoginseng were predicted and found to be responsible for efficient and direct enzymatic biotransformation of 21 triterpenoid saponins via 26 various glycosylation reactions. Among them, UGTPn87 exhibited promiscuous sugar-donor specificity of UDP-glucose (UDP-Glc) and UDP-xylose (UDP-Xyl) by catalyzing the elongation of the second sugar chain at the C3 or/and C20 sites of protopanaxadiol-type saponins with a UDP-Glc or UDP-Xyl donor, as well as at the C20 site of protopanaxadiol-type saponins with a UDP-Glc donor. Two new saponins, Fd-Xyl and Fe-Xyl, were generated by catalyzing the C3-O-Glc xylosylations of notoginsenoside Fd and notoginsenoside Fe when incubated with UGTPn87. Moreover, the complete biosynthetic pathways of 17 saponins were elucidated, among which notoginsenoside L, vinaginsenoside R16, gypenoside LXXV, and gypenoside XVII were revealed in Panax for the first time. A yeast cell factory was constructed with a yield of Rh2 at 354.69 mg/L and a glycosylation ratio of 60.40% in flasks. Our results reveal the biosynthetic pathway of a group of saponins in P. notoginseng and provide a theoretical basis for producing rare and valuable saponins, promoting their industrial application in medicine and functional foods.
Assuntos
Ginsenosídeos , Panax notoginseng , Panax , Saponinas , Triterpenos , Ginsenosídeos/metabolismo , Glicosiltransferases/metabolismo , Panax/metabolismo , Panax notoginseng/metabolismo , Difosfato de Uridina/metabolismoRESUMO
Objective. Inferring the optimized and sparse network structure from the fully connected matrix is a key step in functional connectivity (FC) analysis. However, it is still an urgent problem to be solved, how to exclude the weak and spurious connections contained in functional networks objectively. Most existing binarization methods assume that the network has some certain constraint structures, which lead to changes in the original topology of the network.Approach. To solve this problem, we develop a Trade-off Model between Cost and Topology under Role Division (MCT), which consists of three crucial strategies, including modularity detection, definition of node role, and E-cost optimization algorithm. This algorithm weighs the physical cost and adaptive value of the network while preserving the network structure. Reliability and validity of MCT were evaluated by comparing different binarization methods (efficiency cost optimization, cluster-span threshold, threshold method, and MCT) on synthetic and real data sets.Main results. Experiment results demonstrated that the recovery rate of MCT for networks under noise interference is superior to other methods. In addition, brain networks filtered with MCT had higher network efficiency and shorter characteristic path length, which is more in line with the small world characteristics. Finally, applying MCT to resting-state electroencephalography data from patients with major depression reveals abnormal topology of the patients' connectivity networks, manifested as lower clustering coefficient (CC) and higher global efficiency (GE).Significance. This study provides an objective method for complex network analysis, which may contribute to the future of FC research.
Assuntos
Mapeamento Encefálico , Imageamento por Ressonância Magnética , Encéfalo , Mapeamento Encefálico/métodos , Humanos , Imageamento por Ressonância Magnética/métodos , Vias Neurais , Reprodutibilidade dos TestesRESUMO
According to the WHO, the number of mental disorder patients, especially depression patients, has overgrown and become a leading contributor to the global burden of disease. With the rising of tools such as artificial intelligence, using physiological data to explore new possible physiological indicators of mental disorder and creating new applications for mental disorder diagnosis has become a new research hot topic. We present a multi-modal open dataset for mental-disorder analysis. The dataset includes EEG and recordings of spoken language data from clinically depressed patients and matching normal controls, who were carefully diagnosed and selected by professional psychiatrists in hospitals. The EEG dataset includes data collected using a traditional 128-electrodes mounted elastic cap and a wearable 3-electrode EEG collector for pervasive computing applications. The 128-electrodes EEG signals of 53 participants were recorded as both in resting state and while doing the Dot probe tasks; the 3-electrode EEG signals of 55 participants were recorded in resting-state; the audio data of 52 participants were recorded during interviewing, reading, and picture description.
Assuntos
Transtornos Mentais , Inteligência Artificial , Eletroencefalografia , Humanos , Transtornos Mentais/diagnóstico , Transtornos Mentais/fisiopatologiaRESUMO
PURPOSE: Long non-coding RNA (lncRNA) DNAJC3 antisense RNA 1 (head to head) (DNAJC3-AS1) plays a key role in the progression of several cancers. However, its biological role in hepatocellular carcinoma (HCC) is still unclear. We aimed to investigate the role of DNAJC3-AS1 in the development of HCC and reveal the potential mechanisms. MATERIALS AND METHODS: Expression analysis of DNAJC3-AS1 and microRNA-27b (miR-27b) at both mature and premature levels was determined by RT-qPCR. HCC patients were followed up for 5 years to analyze the prognostic value of DNAJC3-AS1 for HCC. The direct interaction between DNAJC3-AS1 and premature miR-27b was analyzed with RNA pull-down assay. Subcellular analysis of DNAJC3-AS1 was explored by subcellular fractionation assay. DNAJC3-AS1 overexpression and knockdown were carried out to analyze the role of DNAJC3-AS1 in miR-27b maturation. Cell proliferation was analyzed by BrdU assay. RESULTS: DNAJC3-AS1 was overexpressed in HCC and predicts the poor survival. MiR-27b was downregulated at mature miRNA level, but upregulated at premature level. DNAJC3-AS1 directly interacted with premature miR-27b and was localized to both nuclear and cytoplasm. DNAJC3-AS1 overexpression upregulated premature miR-27b and downregulated mature miR-27b, while DNAJC3-AS1 knockdown led to the opposite results. DNAJC3-AS1 suppressed the role of miR-27b in inhibiting cell proliferation. CONCLUSION: DNAJC3-AS1 promotes HCC by sponging premature miR-27b and might be a biomarker and therapeutic target for HCC.
RESUMO
Myocardial ischemia/reperfusion (MI/R) may impair cardiac functions. Dexmedetomidine (DEX) is protective in various clinical cases. Therefore, this study investigated the role and mechanism of DEX in MI/R. The myocardial infarct size, apoptosis, and levels of myocardial enzymes, SOD, ROS, Ca2+, and inflammatory factors in DEX-treated MI/R rats were measured. Differentially expressed microRNAs (miRs) in DEX-treated MI/R rats were detected. miR-346-3p was intervened to assess the effects of DEX on MI/R rats. The targeted binding relationship between miR-346-3p and CaMKIId was predicted and verified. DEX effect on hypoxia/reoxygenation (H/R)-induced cell model was evaluated. The role of CaMKIId in DEX protection was assessed after CaMKIId overexpression in H/R cells. NF-κB pathway and NLRP3 inflammasome-related protein levels were detected. DEX alleviated the myocardial injury and Ca2+ overload in MI/R rats, as evidenced by reduced infarct size, apoptosis and levels of myocardial enzymes, ROS, Ca2+, and inflammatory factors. DEX promoted miR-346-3p expression in MI/R rats, and miR-346-3p knockdown reversed DEX protection on MI/R rats. miR-346-3p targeted CaMKIId. DEX improved H/R-induced cell injury and Ca2+ overload and inhibited NF-κB/NLRP3 inflammasome-related protein levels, which were all reversed by CaMKIId overexpression. DEX alleviated injury and Ca2+ overload in MI/R via regulating the miR-346-3p/CaMKIId axis and inhibiting the NF-κB/NLRP3 inflammasome pathway.
Assuntos
Dexmedetomidina , MicroRNAs , Traumatismo por Reperfusão Miocárdica , Animais , Apoptose , Dexmedetomidina/farmacologia , MicroRNAs/genética , Traumatismo por Reperfusão Miocárdica/tratamento farmacológico , Traumatismo por Reperfusão Miocárdica/genética , Miócitos Cardíacos , RatosRESUMO
At present, most brain functional studies are based on traditional frequency bands to explore the abnormal functional connections and topological organization of patients with depression. However, they ignore the characteristic relationship of electroencephalogram (EEG) signals in the time domain. Therefore, this paper proposes a network decomposition model based on Improved Empirical Mode Decomposition (EMD), it is suitable for time-frequency analysis of brain functional network. On the one hand, it solves the problem of mode mixing on original EMD method, especially on high-density EEG data. On the other hand, by building brain function networks on different intrinsic mode function (IMF), we can perform time-frequency analysis of brain function connections. It provides a new insight for brain function connectivity analysis of major depressive disorder (MDD). Experimental results found that the IMFs waveform decomposed by Improved EMD was more stable and the difference between IMFs was obvious, it indicated that the mode mixing can be effectively solved. Besides, the analysis of the brain network, we found that the changes in MDD functional connectivity on different IMFs, it may be related to the pathological changes for MDD. More statistical results on three network metrics proved that there were significant differences between MDD and normal controls (NC) group. In addition, the aberrant brain network structure of MDDs was also confirmed in the hubs characteristic. These findings may provide potential biomarkers for the clinical diagnosis of MDD patients.