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1.
Inorg Chem ; 2020 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-33021778

RESUMO

Motivated by the predicted unusual short Ni-Ni bond length that is comparable to the intermetallic distance anticipated for the triple bond, the nature of Ni-Ni bonding interaction in the triply carbonyl-bridged geometry of the neutral Ni2(CO)5 complex has been investigated using a range of state-of-the-art quantum chemistry methods. The elaborate analyses manifest that the tribridged Ni2(CO)5 features triple three-center two-electron Ni-C-Ni bonds instead of Ni≡Ni triple bond. The electron pair donated by the bridging carbonyl ligand should be shared by both nickel centers to achieve the favored (18, 18) configuration.

2.
Artigo em Inglês | MEDLINE | ID: mdl-33026145

RESUMO

Genome mining of microbial natural products enables chemists not only to discover the bioactive molecules with novel skeletons, but also to identify the enzymes that catalyze diverse chemical reactions. Exploring the substrate promiscuity and catalytic mechanism of those biosynthetic enzymes facilitate the development of potential biocatalysts. SfaB is an acyl adenylate-forming enzyme that adenylates a unique building block, 3-isocyanobutanoic acid, in the biosynthetic pathway of the diisonitrile natural product SF2768 produced by Streptomyces thioluteus , and this AMP-ligase was demonstrated to accept a broad range of short-chain fatty acids (SCFAs). Herein, we repurpose SfaB to catalyze amidation and thioesterification between those SCFAs and various amine or thiol nucleophiles, thereby providing an alternative enzymatic approach to prepare the corresponding amides and thioesters in vitro.

3.
Phys Chem Chem Phys ; 2020 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-33063806

RESUMO

The homoleptic homodinuclear nickel carbonyl anions Ni2(CO)n- (n = 4-6) are mass-selected in the gas phase and examined with anion photoelectron velocity-map imaging spectroscopy combined with density functional calculations. The doubly carbonyl-bridged structures are found to be favorable for Ni2(CO)n- (n = 4-6). The nature of Ni-Ni bonding in these complexes is analysed with the aid of a range of state-of-the-art quantum chemistry methods. Despite the absence of direct multiple Ni-Ni bonds, the two nickel atoms in Ni2(CO)n- (n = 4-6) complexes are joined by two bridging carbonyl ligands via the sharing three-center two-electron Ni-C-Ni bond in turn to achieve the (16,16), (16,18), and eventually the favored (18,18) configurations.

4.
Neoplasma ; 2020 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-33030958

RESUMO

Highly expressed high mobility group box-1 protein (HMGB1) promotes tumor metastasis. Whether HMGB1 participates in breast cancer cell activation of fibroblasts is unknown. The culture medium of 6 breast cancer cell lines with different migration potential, and with HMGB1 overexpression or knockdown was used to induce fibroblast activation, and collagen and α-SMA expression were measured. We evaluated the migration potential of MDA-MB-231 cells with fibroblasts treated with 3-PO (3-(3-pyridinyl)-1-(4-pyridinyl)-2-propen-1-one) inhibitor, anti-HMGB1 treatment, or RAGE (receptor for advanced glycation end products) knockdown. A lung metastasis murine model was used to evaluate whether the RAGE-knockdown fibroblasts mitigates MDA-MB-231 metastasis. Breast cancer cells that are highly migratory and have a high invasive potential, had higher HMGB1 expression and induced greater fibroblast activation strongly than cells with poorer motility. hrHMGB1 and the supernatants of HMGB1-overexpressed MCF-7 cells promoted fibroblast activation, but loss-HMGB1 of MDA-MB-231 abolished potential. Moreover, a novel mechanism was identified by which HMGB1 facilitated fibroblast activation by RAGE/aerobic glycolysis. Consistently, fibroblasts enhanced MDA-MB-231 metastasis, but the enhancement was reversed by 3-PO inhibition, anti-HMGB1 treatment, or RAGE knockdown in vitro and in vivo. We identified that HMGB1 secreted by breast cancer cells promotes fibroblast activation via RAGE/aerobic glycolysis, and activated fibroblasts enhance breast cancer cell metastasis through increased lactate.

5.
Infect Dis Poverty ; 9(1): 143, 2020 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-33076968

RESUMO

BACKGROUND: Effective management of imported cases is an important part of epidemic prevention and control. Hainan Province, China reported 168 coronavirus disease 2019 (COVID-19), including 112 imported cases on February 19, 2020, but successfully contained the epidemic within 1 month. We described the epidemiological and clinical characteristics of COVID-19 in Hainan and compared these features between imported and local cases to provide information for other international epidemic areas. METHODS: We included 91 patients (56 imported and 35 local cases) from two designated hospitals for COVID-19 in Haikou, China, from January 20 to February 19, 2020. Data on the demographic, epidemiological, clinical and laboratory characteristics were extracted from medical records. Patients were followed until April 21, 2020, and the levels of antibodies at the follow-ups were also analysed by the Wilcoxon matched-pairs signed ranks test. RESULTS: Of the 91 patients, 78 (85.7%) patients were diagnosed within the first three weeks after the first case was identified (Day 1: Jan 22, 2020), while the number of local cases started to increase during the third week. No new cases occurred after Day 29. Fever and cough were two main clinical manifestations. In total, 15 (16.5%) patients were severe, 14 (15.4%) had complicated infections, nine (9.9%) were admitted to the intensive care unit, and three died. The median duration of viral shedding in feces was longer than that in nasopharyngeal swabs (19 days vs 16 days, P = 0.007). Compared with local cases, imported cases were older and had a higher incidence of fever and concurrent infections. There was no difference in outcomes between the two groups. IgG was positive in 92.8% patients (77/83) in the follow-up at week 2 after discharge, while 88.4% patients (38/43) had a reduction in IgG levels in the follow-up at week 4 after discharge, and the median level was lower than that in the follow-up at week 2 (10.95 S/Cut Off (S/CO) vs 15.02 S/CO, P <  0.001). CONCLUSION: Imported cases were more severe than local cases but had similar prognoses. The level of IgG antibodies declined from week 6 to week 8 after onset. The short epidemic period in Hainan suggests that the epidemic could be quickly brought under control if proper timely measures were taken.

6.
J Investig Med ; 2020 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-33051358

RESUMO

The study aimed to compare the clinical characteristics and outcomes of patients with different types (ordinary, severe, and critical) of COVID-19. A total of 1280 patients diagnosed with COVID-19 were retrospectively studied, including 793 ordinary patients, 363 severe patients and 124 critical patients. The impact of comorbidities on prognosis in ordinary, severe, and critical patients were compared and analyzed. The most common comorbidities were hypertension (33.0%), followed by diabetes (14.4%). The length of hospital stay and time from the onset to discharge were significantly longer in ordinary patients with comorbidities compared with those without comorbidities. Critical patients with comorbidities had significantly lower cure rate (19.3% vs 38.9%, p<0.05) and significantly higher mortality rate (53.4% vs 33.3%, p<0.05) compared with those without comorbidities. The time from onset to discharge was significantly longer in ordinary patients with hypertension compared with those without hypertension. The mortality rate of critical patients with diabetes was higher than that of patients without diabetes (71.4% vs 42.7%, p<0.05). Men had a significantly increased risk of death than women (OR=4.395, 95% CI 1.896 to 10.185, p<0.05); patients with diabetes had higher risk of death (OR=3.542, 95% CI 1.167 to 10.750, p<0.05). Comorbidities prolonged treatment time in ordinary patients, increased the mortality rate and reduced the cure rate of critical patients; hypertension and diabetes may be important factors affecting the clinical course and prognosis of ordinary and critical patients, respectively.

7.
Biomaterials ; 265: 120448, 2020 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-33068892

RESUMO

It is critical for the clinical success to take the anti-inflammatory function into consideration when integrating the neurogenesis into the nerve repair materials. To this aim, we prepared mesenchymal stem cell (MSC) spheroids-loaded collagen (Col) hydrogels with combined superior anti-inflammatory efficacy and neurogenic activity. The size of the MSC spheroids showed a strong modulation effect on both functions, and the MSC spheroids-100 sample exhibited the best neuronal and anti-inflammatory potentials. The observed dual functions were likely based on the elevated intrinsic cell-cell contacts and cell-extracellular matrix interactions from the MSC spheroids. MSC self-assembly as spheroids expedited the secretions of endogenous trophic factors and extracellular matrix (ECM), which was beneficial to drive neural stem cell differentiation into the neuronal lineage. In addition, the formation of the MSC spheroids secreted more amounts and types of cytokines as well as immunomodulatory paracrine factors to suppress LPS-induced inflammatory reaction. LC-MS/MS analysis further demonstrated that MSC spheroids contributed to the activation of neuroactive ligand-receptor interaction, thereby triggering downstream PI3K-Akt signal pathway, which was likely due to the acceleration of ECM-receptor interaction, gap junction and tight junction. Importantly, inhibiting Akt pathway significantly suppressed the neuronal differentiation, indicating that PI3K-Akt signal pathway was critically involved in the Col-MSC spheroid hydrogel mediated neuroprotection and neurogenesis. Such findings not only provided a simple approach for improving MSC-based therapies for neuron-related diseases, but also shed insight on understanding the underlying mechanisms of MSC-mediated neuronal differentiation.

8.
J Dairy Sci ; 2020 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-33041026

RESUMO

Heat treatment is the most common method used to make milk safe; however, it leads to changes in the organoleptic and nutritional properties of milk. This study aimed to investigate the effects of different heat treatments on nutrients and microbiota of camel milk. The results showed that the nutrient composition of camel milk could be influenced by heat treatment. Ultra-high-temperature treatment of samples significantly reduced levels of camel milk proteins, vitamin C, and lactose, but did not significantly alter the amino acids content. Analysis of 16S rRNA amplicon sequences demonstrated that the composition of the intestinal microbiota of mice fed different heat-treated camel milks changed, as did the production of short-chain fatty acids as determined by gas chromatography-mass spectrometry. High temperature/short time treatment had similar effects to UHT treatment on microbial diversity of camel milk; however, the low temperature/long time treatment had different effects. In addition, higher-temperature treatments changed the abundance of key bacteria at the genus level. These results demonstrated that different heat treatments not only resulted in some nutrient loss, but also changed the proliferation of some probiotic genera. Our results could provide the basis for the potential industrial application of camel milk processing technologies.

9.
Artigo em Inglês | MEDLINE | ID: mdl-32898955

RESUMO

Objective: Old World camels are a valuable genetic resource for many countries around the world due to their adaptation to the desert environment. At present, Old World camels have encountered the challenge of unprecedented loss of genetic resources. Through our research, we would reveal the population structure and genetic variation in Old World camel populations, which provide a theoretical basis for understanding the germplasm resources and origin and evolution of different Old World camel populations.. Methods: In the present study, we assessed mtDNA control region sequences of 182 individuals from Old World camels to unravel genetic diversity, phylogeography, and demographic dynamics. Results: Thirty-two haplotypes confirmed by 54 polymorphic sites were identified in the 156 sequences, which included 129 domestic and 27 wild Bactrian camels. Meanwhile, 14 haplotypes were defined by 47 polymorphic sites from 26 sequences in the dromedaries. The wild Bactrian camel population showed the lowest haplotype and nucleotide diversity, while the dromedaries investigated had the highest. The phylogenetic analysis suggests that there are several shared haplotypes in different Bactrian camel populations, and that there has been genetic introgression between domestic Bactrian camels and dromedaries. In addition, positive values of Tajima's D and Fu's Fs test demonstrated a decrease in population size and/or balancing selection in the wild Bactrian camel population. In contrast, the negative values of Tajima's D and Fu's Fs test in East Asian Bactrian camel populations explained the demographic expansion and/or positive selection. Conclusion: In summary, we report novel information regarding the genetic diversity, population structure and demographic dynamics of Old World camels. The findings obtained from the present study reveal that abundant genetic diversity occurs in domestic Bactrian camel populations and dromedaries, while there are low levels of haplotype and nucleotide diversity in the wild Bactrian camel population.

10.
J Virol ; 2020 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-32907984

RESUMO

Numerous peptides inhibit the entry of enveloped viruses into cells. Some of these peptides have been shown to inhibit multiple unrelated viruses. We have suggested that such broad-spectrum antiviral peptides share a property called interfacial activity; they are somewhat hydrophobic and amphipathic with a propensity to interact with the interfacial zones of lipid bilayer membranes. Here, we further test the hypothesis that such interfacial activity is a correlate of broad-spectrum antiviral activity. In this study, several families of peptides, selected for their ability to partition into and disrupt membrane integrity, but with no known antiviral activity, were tested for their ability to inhibit multiple diverse enveloped viruses. These include Lassa pseudovirus, influenza virus, dengue virus type 2, herpes simplex virus type 1, and also non-enveloped human adenovirus 5. Various families of interfacially-active peptides caused potent inhibition of all enveloped viruses tested, at low and sub-micromolar concentrations; well below the range in which they are toxic to mammalian cells. These membrane-active peptides block uptake and fusion with the host cell by rapidly interacting directly with virions, destabilizing the viral envelope, and driving virus aggregation and/or inter-virion envelope fusion. We speculate that the molecular characteristics shared by these peptides can be exploited to enable the design, optimization, or molecular evolution of novel broad-spectrum antiviral therapeutics.IMPORTANCE New classes of antiviral drugs are needed to treat the ever-changing viral disease landscape. Current antiviral drugs only treat a small number of viral diseases, leaving many patients with established or emerging infections to be treated solely with supportive care. Recent antiviral peptide research has produced numerous membrane-interacting peptides that inhibit diverse enveloped viruses in vitro and in vivo Peptide therapeutics are becoming more common, with over 60 FDA approved peptides for clinical use. Included in this class of therapeutics is enfuvirtide, a 36-residue peptide drug that inhibits HIV entry/fusion. Due to their broad-spectrum mechanism of action and enormous potential sequence diversity, peptides that inhibit virus entry could potentially fulfill the need for new antiviral therapeutics; however, a better understanding of their mechanism is needed for the optimization or evolution of sequence design to combat the wide landscape of viral disease.

12.
Biomed Res Int ; 2020: 5287131, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32879883

RESUMO

Professional phagocytes such as dendritic cells and macrophages can ingest particles larger than 0.5 µm in diameter. Epithelial cells are nonprofessional phagocytes that cannot ingest pathogenic microorganisms, but they can ingest apoptotic cells. Inhibition of the engulfment of apoptotic cells by the airway epithelium can cause severe airway inflammation. Vascular endothelial growth factor (VEGF) is an angiogenesis-promoting factor that can mediate allergic airway inflammation and can promote airway epithelial cells (AECs) proliferation, but it is not clear whether it affects the engulfment of apoptotic cells by AECs. In the present study, VEGF inhibited engulfment of apoptotic cells by AECs via binding to VEGF receptor(R)2. This inhibitory effect of VEGF was not influenced by masking of phosphatidylserine (PS) on the surface of apoptotic cells and was partially mediated by the PI3K-Akt signaling pathway. VEGF inhibition of phagocytosis involved polymerization of actin and downregulation of the expression of the phagocytic-associated protein Beclin-1 in AECs. Since engulfment of apoptotic cells by AECs is an important mechanism for airway inflammation regression, VEGF inhibition of the engulfment of apoptotic cells by airway epithelial cells may be important for mediating allergic airway inflammation.

13.
Dis Markers ; 2020: 5068067, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32963636

RESUMO

6,12-Diphenyl-3,9-diazatetraasterane-1, 5, 7, 11-tetracarboxylate (DDTC) has been synthesized by the photodimerization of 4-phenyl-1,4-dihydropyridine-3,5-dicarboxylate. The potential of theercvantitumor activity and mechanism were investigated in vitro using MTT assay in human lung cancer cell line A549, ovarian cancer cell lines SKOV3 and A2780, breast cancer cell line MCF-7, gastric cancer cell line BGC-823, colon cancer cell line HT29, prostate cancer cell line DU145, and liver cancer cell line SMMC7721. The results show that DDTC can inhibit the growth of ovarian cancer SKOV3 and A2780 cells. The best IC50 value is approximately 5.29 ± 0.38 and 4.29 ± 0.39 µM, respectively. DDTC induced the cell cycle arrest in the G2 phase by flow cytometric analysis. The migration and invasion of ovarian cancer SKOV3 and A2780 cells were inhibited by DDTC. DDTC could increase the expression protein level of E-cadherin in A2780 cells and ascend the expression protein and mRNA levels of E-cadherin in SKOV3 cells. DDTC could also decrease the protein and mRNA expression of EMT (epithelial-to-mesenchymal transition) markers of N-cadherin and Vimentin. mRNA and protein expression level of checkpoint kinase 1 (Chk1) were significantly increased and expressions of cyclin-dependent kinase (CDK1) and cell division cycle 25a (Cdc25a) were decreased in the SKOV3 and A2780 cell lines. Moreover, DDTC induced apoptosis by the cleavage and activation of caspase 3 and caspase 9.

14.
Sensors (Basel) ; 20(18)2020 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-32937788

RESUMO

Image neural style transfer is a process of utilizing convolutional neural networks to render a content image based on a style image. The algorithm can compute a stylized image with original content from the given content image but a new style from the given style image. Style transfer has become a hot topic both in academic literature and industrial applications. The stylized results of current existing models are not ideal because of the color difference between two input images and the inconspicuous details of content image. To solve the problems, we propose two style transfer models based on robust nonparametric distribution transfer. The first model converts the color probability density function of the content image into that of the style image before style transfer. When the color dynamic range of the content image is smaller than that of style image, this model renders more reasonable spatial structure than the existing models. Then, an adaptive detail-enhanced exposure correction algorithm is proposed for underexposed images. Based this, the second model is proposed for the style transfer of underexposed content images. It can further improve the stylized results of underexposed images. Compared with popular methods, the proposed methods achieve the satisfactory qualitative and quantitative results.

15.
Clin Exp Rheumatol ; 2020 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-32940214

RESUMO

OBJECTIVES: Serum soluble CD25 (sCD25) is associated with T cell activation and regarded as a marker of disease activity in autoimmune disorders. The purpose of our study was to investigate the clinical relevance of sCD25 in patients with primary Sjögren's syndrome (pSS). METHODS: Sixty-five pSS patients and 60 healthy controls (HCs) with comparable age and gender were recruited. Serum samples were collected and sCD25 concentrations were measured using enzyme-linked immunosorbent assay (ELISA). Clinical and laboratory changes were examined after 12 weeks of treatment, and data were recorded in detail. The European League Against Rheumatism Sjögren's syndrome disease activity index (ESSDAI) was used to evaluate disease activity. RESULTS: Serum sCD25 levels were significantly increased in pSS patients, compared to HCs (p<0.001). The increased sCD25 were positively associated with ESSDAI scores (p=0.006), especially the haematological domain (p=0.002), and erythrocyte sedimentation rate, and levels of C-reactive protein, immunoglobulin G and -globulin (p<0.001, <0.001, 0.045 and 0.011, respectively). High sCD25 was strongly associated with anaemia (p=0.014) and was inversely correlated with haemoglobin levels (p=0.002). In further analysis, we found that patients with autoimmune haemolytic anaemia (AIHA) had the highest levels of sCD25, followed by patients with chronic disease of anaemia (ACD) and iron-deficiency anaemia (IDA). With the improvement after treatment, serum sCD25 levels were significantly decreased, accompanied by resolved anaemia compared to baseline (p=0.001). CONCLUSIONS: sCD25 was associated with disease severity, especially anaemia in patients with pSS and may serve as an indicator of disease activity.

16.
Soft Matter ; 2020 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-32926046

RESUMO

Self-healable polyurethanes can be used in various fields for extended service life and reduced maintenance costs. It is generally believed that the shape memory effect is helpful for achieving a high healing efficiency. The morphological features were focused on in this study as microphase separation is one of the main factors affecting various performances of polyurethanes, including their shape memory behavior and mechanical properties. Microphase separation can be regulated by changing the content and types of the hard segments. With this in mind, polyurethanes from polycaprolactone diol, hexamethylene diisocyanate, and different chain extenders were synthesized, characterized, and designed as promising self-healing polymers. All the polyurethane specimens were equipped with a similar content of hard segments but diverse types, such as aliphatic, aromatic, and disulfide-bonded. Differential scanning calorimetry, thermogravimetric analysis, X-ray diffractometry, infrared spectroscopy, and atomic force microscopy were used to describe the microstructures of the polyurethanes, including the crystalline regions. The relationship between the microphase separation structures and material properties was focused on in this examination. Various properties, including the thermal stability, mechanical behavior, hydrophobicity, and self-healing efficiency showed significant differences due to the change in the hard segments' structure and multiphase distribution. The aliphatic disulfide stimulated the conformation of a proper microphase separation structure (the large heterogeneous structure at physical length scales as well as a more sufficient combination of soft and hard phases), which helped to improve the healing effect as much as possible by effective wound closure and the exchange reactions of disulfide bonds.

17.
Mol Ther Nucleic Acids ; 22: 17-26, 2020 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-32891980

RESUMO

Neuroblastoma is the primary cause of cancer death in childhood. METTL14 is tightly linked to cancer. However, whether single-nucleotide polymorphisms (SNPs) in the METTL14 gene could predispose to neuroblastoma susceptibility lacks evidence. With an epidemiology case-control study, associations between METTL14 gene SNPs and overall risk for neuroblastoma were estimated in 898 cases and 1,734 controls. Following that, stratified analysis was performed. Among the five analyzed SNPs, rs298982 G>A and rs62328061 A>G exhibited a significant association with decreased susceptibility to neuroblastoma, whereas the associations with increased neuroblastoma susceptibility were observed for rs9884978 G>A and rs4834698 T>C. Moreover, subjects carrying two to five risk genotypes were more inclined to develop neuroblastoma than those with zero to one risk genotypes. The stratified analysis further demonstrated the protective effect of rs298982 G>A and rs62328061 A>G, as well as the predisposing effect of rs4834698 T>C and two to five risk genotypes, in certain subgroups. Haplotype analysis was performed. Moreover, false-positive report probability analysis validated the reliability of the significant results. The expression quantitative trait locus analysis revealed that rs298982 is correlated with the expression levels of its surrounding genes. Our results suggest that some SNPs in the METTL14 gene are associated with predisposition to neuroblastoma.

18.
Neuropharmacology ; 180: 108291, 2020 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-32931812

RESUMO

Voltage-gated sodium channels (VGSCs) are responsible for the generation and propagation of action potentials in excitable cells and are the molecular targets of an array of neurotoxins. BmK NT1, an α-scorpion toxin obtained from the scorpion Buthus martensii Karsch (BmK), produces neurotoxicity that is associated with extracellular Ca2+ influx through Na+-Ca2+ exchangers, N-methyl-d-aspartic acid (NMDA) receptors, and L-type Ca2+ channels in cultured cerebellar granule cells (CGCs). In the present study, we demonstrated that BmK NT1 triggered concentration-dependent release of excitatory neurotransmitters, glutamate and aspartate; both effects were eliminated by VGSC blocker, tetrodotoxin. More importantly, we demonstrated that a threshold concentration of BmK NT1 that produced marginal Ca2+ influx and neuronal death augmented glutamate-induced Ca2+ elevation and neuronal death in CGCs. BmK NT1-augmented glutamate-induced Ca2+ influx and neuronal death were suppressed by tetrodotoxin and MK-801 suggesting that the augmentation was through activation of VGSCs and NMDA receptors. Consistently, BmK NT1 also enhanced NMDA-induced Ca2+ influx. Further mechanistic investigations demonstrated that BmK NT1 increased the expression level of NMDA receptors on the plasma membrane and increased the phosphorylation level of NR2B at Tyr1472. Src family kinase inhibitor, 1-tert-butyl-3-(4-chlorophenyl)pyrazolo[3,4-d]pyrimidin-4-yl]amine (PP2), but not the inactive analogue, 4-amino-1-phenylpyrazolo[3,4-d]pyrimidine (PP3), eliminated BmK NT1-triggered NR2B phosphorylation, NMDA receptor trafficking, as well as BmK NT1-augmented NMDA Ca2+ response and neuronal death. Considered together, these data demonstrated that both presynaptic (excitatory amino acid release) and postsynaptic mechanisms (augmentation of NMDA receptor function) are critical for VGSC activation-induced neurotoxicity in primary CGC cultures.

19.
Talanta ; 219: 121173, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32887095

RESUMO

Sensitive and specific detection of microRNAs (miRNAs) is of great significance for early cancer diagnosis. Here we report a simple and sensitive fluorescence signal amplification strategy that based on DSN/TdT recycling digestion for miRNA detection. DSN initiates DNA digestion on 3'-phosphate-primer/miRNA heteroduplex which causes miRNA recycle. The digested DNA strands with 3'-OH ends enable TdT to synthesize a polydeoxyguanylic tails on the 3'-end. The DNAs with polydeoxyguanylic tails are converted to double-stranded-DNA prior to initiation of DSN/TdT recycling digestion. With the cooperation of TdT and DSN, a new round of digestion and extension is triggered, leading to massive fluorophores separating and signal amplification. The amplification strategy produces large amounts of 3'-OH probes that can be used directly for dsDNA enrichment and DSN digestion. Moreover, both DSN digestion and TdT extension are sequence-independent reaction without the need of complex sequences design. In addition, this strategy is utilized to analyze miRNA samples from MCF-7 cell lysates and Cu (II) ion samples, indicating its potential application in actual sample analysis. The method shows a promising analytical platform for DNA nicking-related studies and tumor biomarkers measuring in clinical diagnostics.

20.
Mol Cell Endocrinol ; 518: 111004, 2020 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-32871224

RESUMO

Insulin is a key hormone for maintaining glucose homeostasis in organisms. In general, deficiency of insulin synthesis and secretion results in type I diabetes, whereas insulin resistance leads to type 2 diabetes. Cell division cycle 42 (CDC42), a member of Rho GTPases family, has been shown as an essential regulator in the second phase of glucose-induced insulin secretion in pancreatic islets ß cells in vitro. However, the effect of CDC42 on insulin expression has not been explored. Here we reported that the glucose-induced insulin expression and secretion were significantly inhibited in mice lacking CDC42 gene in pancreatic ß cells (Rip-CDC42cKO) in vivo and in vitro. Deletion of CDC42 gene in pancreatic ß cells did not affect survival or reproduction in mice. However, the Rip-CDC42cKO mice showed the systemic glucose intolerance and the decrease of glucose-induced insulin secretion without apparent alterations of peripheral tissues insulin sensitivity and the morphology of islets. Furthermore, we demonstrated that deletion of CDC42 gene in pancreatic ß cells significantly attenuated the insulin expression through inhibiting the ERK1/2-NeuroD1 signaling pathway. Taken together, our study presents novel evidence that CDC42 is an important modulator in glucose-induced insulin expression as well as insulin secretion in pancreatic ß cells.

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