Effect of different substituents on the fluorescence properties of precursors of synthetic GFP analogues and a polarity-sensitive lipid droplet probe with AIE properties for imaging cells and zebrafish.

The green fluorescent protein (GFP) is a purely natural specialty protein that has been widely used to design synthetic fluorescent probes. In the present work we designed and synthesized a series of fluorescent compounds akin to GFP precursors by a one-step method, and investigated the luminescence properties of the fluorescent compounds by varying the substituents. We presented the first systematic summary of the photophysical data including extinction coefficients and fluorescence quantum yields for this class of fluorescent dyes. We also carried out density functional theory (DFT) calculations for these dyes to investigate the effect of electronic effects due to different substituents. These studied optical properties may provide a reference for later probe design. More interestingly, we have developed a polarity-sensitive lipid droplet probe T-LD with AIE properties on this basis. The probe exhibited not only favorable pH stability and kinetic stability in terms of optical properties, but also solvent discolouration and polarity-sensitive properties, and was able to label intracellular lipid droplets. We successfully applied the probe for intracellular lipid droplet level monitoring and zebrafish imaging.

Isolated unilateral oculomotor palsy caused by pure midbrain infarction: a case report.

Purpose: Multiple etiologies may cause oculomotor nerve palsies. Identification of different etiologies is very important for subsequent treatment. Midbrain infarction is a rare cause of oculomotor nerve palsy. Materials and methods: We herein present a case of isolated unilateral oculomotor paresis caused by pure midbrain infarction. Results: Her pupillary sphincter and inferior rectus muscles were selectively spared. The symptoms were completely relieved after two months of antiplatelet therapy. We proposed that fibers from Edinger-Westphal nucleus and inferior rectus nucleus do not course through the paramedian area of the midbrain. Conclusions: Our report adds to the understanding of fascicles arrangement in the midbrain.

Ridge-furrow with grass straw mulching farming system to boost rainfed wheat productivity and water use efficiency in semiarid Kenya.

BACKGROUND: Ridge-furrow mulching farming systems (RFMs) aim to increase field productivity and improve water use efficiency. To explore environment-friendly and efficient farming systems is a central aspect of rainfed wheat field management in Kenya where rainfall utilization is at a low level. We introduced RFMs (including plastic film and grass straw mulching) to semiarid Kenya to evaluate the effects on field productivity, rainwater utilization, soil quality and economic profitability using old and modern wheat cultivars from 2012 to 2013. RESULTS: Across the cultivars, the RFMs increased grain yield, aboveground biomass and water use efficiency by 74-163%, 36-104% and 89-273%, respectively, compared with conventional flat planting (control). RFMs significantly shortened the vegetative period while prolonging the reproductive period. The net economic output under RFMs was 74-165% higher than that of the control. Grass straw mulching achieved the highest economic output to input ratio, almost 45% higher than plastic film mulching, despite the former harvested only 82% of the maximum field productivity of the latter. Compared with the control, grass straw mulching promoted the contents of soil organic carbon, total nitrogen and C:N ratio by 14%, 8% and 5%, respectively, while obviously decreased values of these parameters were observed under plastic mulching. CONCLUSIONS: Through reducing soil water loss, and improving rainwater use efficiency and soil quality, ridge-furrow grass straw mulching would be a sustainable option for boosting field productivity and thus ensuring local food security in rainfed agricultural areas of Kenya. © 2020 Society of Chemical Industry.

Tunable Electrochemical C-N versus N-N Bond Formation of Nitrogen-Centered Radicals Enabled by Dehydrogenative Dearomatization: Biological Applications.

Herein, an environmentally friendly electrochemical approach is reported that takes advantage of the captodative effect and delocalization effect to generate nitrogen-centered radicals (NCRs). By changing the reaction parameters of the electrode material and feedstock solubility, dearomatization enabled a selective dehydrogenative C-N versus N-N bond formation reaction. Hence, pyrido[1,2-a]benzimidazole and tetraarylhydrazine frameworks were prepared through a sustainable transition-metal- and exogenous oxidant-free strategy with broad generality. Bioactivity assays demonstrated that pyrido[1,2-a]benzimidazoles displayed antimicrobial activity and cytotoxicity against human cancer cells. Compound 21 exhibited good photochemical properties with a large Stokes shift (approximately 130 nm) and was successfully applied to subcellular imaging. A preliminary mechanism investigation and density functional theory (DFT) calculations revealed the possible reaction pathway.

Single Fluorescent Probe for Dual-Imaging Viscosity and H2O2 in Mitochondria with Different Fluorescence Signals in Living Cells.

Mitochondria, as essential and interesting organelles within the eukaryotic cells, play key roles in a variety of pathologies, and its abnormalities are closely associated with Alzheimer's disease (AD) and other diseases. Studies have shown that the abnormal of viscosity and concentration of hydrogen peroxide in mitochondria were all associated with AD. Accordingly, the detection of viscosity and hydrogen peroxide in mitochondria has attracted great attention. However, it remains a great challenge to explore a single probe, which can dual-detect the viscosity and H2O2 in mitochondria. Herein, in two ways to prevent the twisted internal charge transfer (TICT) process, we designed and sythesized the first dual-detection fluorescent probe Mito-VH that can visualize viscosity and H2O2 in mitochondria with different fluorescence signals in living cells.

[Effects of safflower injection on HEL leukemia cell proliferation and apoptosis and relevant molecular mechanisms].

OBJECTIVE: To study the effect of safflower injection on the proliferation and apoptosis of human leukemia cell line HEL and the relevant molecular mechanisms. METHODS: HEL cells were treated with different concentrations of safflower injection. HEL cells without safflower injection treatment were used as the control group. MTT method was used to detect the inhibitory rate of the HEL cells at 24, 48 and 72 hours after various concentrations of safflower injection treatment (10, 20, 30, 40 and 50 mg/mL). The cell cycle and apoptosis were detected using flow cytometry and the HOXB3-mRNA expression was measured by RT-PCR at 48 hours after safflower injection treatment (10, 20 and 30 mg/mL). RESULTS: Compared with the control group, various concentrations of safflower injection inhibited HEL cell proliferation in a dose-dependent manner (P<0.05). At 48 hours after various concentrations of safflower injection treatment, the number of treated cells in the G2/M phase increased, but that in the S phase decreased, and the apoptosis rate was significantly higher than that in the control group, with a dose-dependent manner (P<0.05). The expression of HOXB3-mRNA in safflower injection-treated cells decreased in a dose-dependent manner compared with the control group (P<0.05). CONCLUSIONS: Safflower injection can inhibit proliferation and induce apoptosis of HEL cells in vitro, and its underlying mechanisms may involve down-regulation of the HOXB3-mRNA expression.

[Determination of Th9 cells and IL-9 in children with Mycoplasma pneumoniae infection].

OBJECTIVE: To investigate the clinical significance of T helper type 9 (Th9) cells and interleukin-9 (IL-9) in children suffering from Mycoplasma pneumoniae (MP) infection. METHODS: A total of 86 children who were diagnosed with MP infection between January 2013 and June 2014 were classified into upper respiratory infection (URI) group (n=29), mild MP pneumonia (MPP) group (n=32) and severe MPP group (n=25). Twenty-eight healthy children were used as the control group. Peripheral blood mononuclear cells were isolated by Ficoll density gradient centrifugation, and the percentage of Th9 cells in peripheral blood was measured by flow cytometry. Serum IL-9 level was determined using ELISA. RESULTS: The URI, mild MPP, and severe MPP groups had significantly higher percentages of Th9 cells and IL-9 levels than the control group (P<0.05); the mild MPP and severe MPP groups had significantly higher percentages of Th9 cells and IL-9 levels than the URI group (P<0.05), and the two indices were significantly higher in the severe MPP group than in the mild MPP group (P<0.01). CONCLUSIONS: Children with MP infection have an elevated percentage of Th9 cells and IL-9 expression, both of which are positively correlated with the severity of the disease. It can be predicted that Th9 cells and IL-9 can be used as evaluation indicators for the progression and outcome of children with MP infection.

Paroxetine ameliorates lipopolysaccharide-induced microglia activation via differential regulation of MAPK signaling.

BACKGROUND: Paroxetine, a selective serotonin reuptake inhibitor for counteracting depression, has been recently suggested as having a role in prevention of dopaminergic neuronal degeneration in substantia nigra, a hallmark of Parkinson's disease (PD). The pathogenesis of this type of neurological disorders often involves the activation of microglia and associated inflammatory processes. Thus in this study we aimed to understand the role of paroxetine in microglia activation and to elucidate the underlying mechanism(s). METHODS: BV2 and primary microglial cells were pretreated with paroxetine and stimulated with lipopolysaccharide (LPS). Cells were assessed for the responses of pro-inflammatory mediator and cytokines, and the related signaling pathways were evaluated and analyzed in BV2 cells. RESULTS: Paroxetine significantly inhibited LPS-induced production of nitric oxide (NO) and pro-inflammatory cytokines such as TNF-α and IL-1ß. Further analysis showed inducible nitric oxide synthase (iNOS) and mRNA expression of TNF-α and IL-1ß were attenuated by paroxetine pretreatment. Analyses in signaling pathways demonstrated that paroxetine led to suppression of LPS-induced JNK1/2 activation and baseline ERK1/2 activity, but had little effect on the activation of p38 and p65/NF-κB. Interference with specific inhibitors revealed that paroxetine-mediated suppression of NO production was via JNK1/2 pathway while the cytokine suppression was via both JNK1/2 and ERK1/2 pathways. Furthermore, conditioned media culture showed that paroxetine suppressed the microglia-mediated neurotoxicity. CONCLUSIONS: Paroxetine inhibits LPS-stimulated microglia activation through collective regulation of JNK1/2 and ERK1/2 signaling. Our results indicate a potential role of paroxetine in neuroprotection via its anti-neuroinflammatory effect besides targeting for depression.

Iron-catalyzed radical aryldifluoromethylation of activated alkenes to difluoromethylated oxindoles.

An iron-catalyzed aryldifluoromethylation of activated alkenes under mild reaction conditions has been developed, which is a rare example where a cosolvent is used to improve the reaction yield along with Fenton's reagent and thus provides an economic and green method for the synthesis of a variety of difluoromethylated oxindoles. Preliminary mechanistic investigations indicate a radical addition path.

Design, synthesis, and biological evaluation of novel trifluoromethyl indoles as potent HIV-1 NNRTIs with an improved drug resistance profile.

A novel series of trifluoromethyl indole derivatives have been designed, synthesized and evaluated for anti-HIV-1 activities in MT-2 cells. The hydrophobic constant, acute toxicity, carcinogenicity and mutagenicity were predicted. Trifluoromethyl indoles 10i and 10k showed extremely promising activities against WT HIV-1 with IC50 values at the low nanomolar level, similar to efavirenz, better than nevirapine, and also possessed higher potency towards the drug-resistant mutant strain Y181C than nevirapine. Preliminary SAR and docking studies of detailed binding mode provided some insights for discovery of more potent NNRTIs.

[Epigallocatechin gallate attenuates the expression of regulated upon activation normal T cell expressed and secreted induced by lipopolysaccharide in human retinal endothelial cells].

The present study was undertaken to determine the effect of epigallocatechin gallate (EGCG) on lipopolysaccharide (LPS)-induced production of inflammatory chemokine regulated upon activation normal T cell expressed and secreted (RANTES) in human retinal endothelial cells (HRECs) and to explore the underlying regulatory mechanism. HRECs were stimulated with LPS in the presence or absence of EGCG at various concentrations (100, 50, 25, 12.5, 6.25 µmol/L). The optimum concentration of drug was determined by a real-time cell-electronic sensing (RT-CES) system, and MTS chromatometry was used to detect the toxicity of LPS and EGCG on HRECs. RANTES production in the culture supernatant was measured by ELISA. The expression levels of Akt and phosphorylated Akt were examined by Western blot assay. The result showed that LPS markedly stimulated RANTES secretion from HRECs. EGCG treatment significantly suppressed LPS-induced RANTES secretion in a dose-dependent manner. Furthermore, EGCG exhibited a dose-dependent inhibitory effect on LPS-induced phosphorylation of Akt. Taken together, our data suggest that EGCG suppresses LPS-induced RANTES secretion, possibly via inhibiting Akt phosphorylation in HRECs.

Association analyses of apolipoprotein E genotypes and cognitive performance in patients with Parkinson's disease.

BACKGROUND: Cognitive impairment is a common non-motor symptom of Parkinson's disease (PD). The apolipoprotein E (APOE) ε4 genotype increases the risk of Alzheimer's disease (AD). However, the effect of APOEε4 on cognitive function of PD patients remains unclear. In this study, we aimed to understand whether and how carrying APOEε4 affects cognitive performance in patients with early-stage and advanced PD. METHODS: A total of 119 Chinese early-stage PD patients were recruited. Movement Disorder Society Unified Parkinson's Disease Rating Scale, Hamilton anxiety scale, Hamilton depression scale, non-motor symptoms scale, Mini-mental State Examination, Montreal Cognitive Assessment, and Fazekas scale were evaluated. APOE genotypes were determined by polymerase chain reactions and direct sequencing. Demographic and clinical information of 521 early-stage and 262 advanced PD patients were obtained from Parkinson's Progression Marker Initiative (PPMI). RESULTS: No significant difference in cognitive performance was found between ApoEε4 carriers and non-carriers in early-stage PD patients from our cohort and PPMI. The cerebrospinal fluid (CSF) Amyloid Beta 42 (Aß42) level was significantly lower in ApoEε4 carrier than non-carriers in early-stage PD patients from PPMI. In advanced PD patients from PPMI, the BJLOT, HVLT retention and SDMT scores seem to be lower in ApoEε4 carriers without reach the statistical significance. CONCLUSIONS: APOEε4 carriage does not affect the cognitive performance of early-stage PD patients. However, it may promote the decline of CSF Aß42 level and the associated amyloidopathy, which is likely to further contribute to the cognitive dysfunction of PD patients in the advanced stage.

Pd(II)-catalyzed enantioselective C-H activation/C-O bond formation: synthesis of chiral benzofuranones.

Pd(II)-catalyzed enantioselective C-H activation of phenylacetic acids followed by an intramolecular C-O bond formation afforded chiral benzofuranones. This reaction provides the first example of enantioselecctive C-H functionalizations through Pd(II)/Pd(IV) redox catalysis.

Diverse reactivity in microwave-promoted catalyst-free coupling of substituted anilines with ethyl trifluoropyruvate and biological evaluation.

Diverse reactivity by coupling of substituted anilines with ethyl trifluoropyruvate was developed under microwave irradiation without catalysts to generate 3-trifluoromethyl-3-hydroxy oxindoles, aromatic hydroxy trifluoromethyl esters, and 1,2-dicarbonyl compounds in a fast and efficient manner. The plausible mechanism for obtaining different products was proposed. Furthermore, the anti-HIV activity of aromatic hydroxy trifluoromethyl esters was first reported. The best inhibitory activity against wild-type HIV-1 IIIB was exemplified by trifluoromethyloxindole 3q with an IC50 = 5.8 µM, which also displayed potential activity against Y181C mutant virus with an IC50 = 7.5 µM. More significantly, the activities of oxindoles 3q and 3r to inhibit K103N/Y181C double mutant HIV-1 reverse transcriptase (RT) are probably similar to that of the second-generation nonnucleoside inhibitor HBY 097 by docking calculation.

A novel fluorescent probe with ACQ-AIE conversion by alkyl chain engineering for simultaneous visualization of lipid droplets and lysosomes.

The AIE bio-probes have attracted extensive attention because of their good brightness, long-term in situ retention ability, photostability and low cytotoxicity. Recently, the transformation of ACQ to AIE has become very popular, which is very important for the further development of AIE probes. Herein, a series of novel dyes (NR-Lyso-Ⅰ, NR-Lyso-Ⅱ, NR-Lyso-III, NR-Lyso-IV) were designed and synthesized. It was found that alkylation of 4-aminonaphthalimide could achieve the transformation of the dye from ACQ to AIE effect due to the growth of carbon chain. Moreover, the AIE probe NR-Lyso-IV exhibited dual-state emission (DSE) and large Stokes shift (＞100 nm), excellent selectivity, photostability, and low cytotoxicity, which was able to simultaneous visualize the lipid droplets (LDs) and lysosomes of HeLa cells and zebrafish.

A series of fluorescent dyes based on 4-phenylacetylene-1,8-naphthalimide: Synthesis, theoretical calculations, photophysical properties and application in two-color imaging and dynamic behavior monitoring of lipid droplets and lysosomes.

A series of fluorescent dyes (NapPAs) based on 4-phenylacetylene-1,8-naphthalimide were synthesized and characterized, whose conjugated structures were extended by the introduction of phenylethynyl. Furthermore, changes in the photophysical properties of the dyes when substituents with varying electron richness were introduced at the p-position of phenylacetylene were studied. The theoretical calculation of the dye molecules was carried out by B3LYP functional and 6-31G(d,p) basis set, and the effects of different substituents at the p-position of phenylacetylene on the electronic structure and photophysical properties of the dyes were studied by theoretical calculation results. Theoretical calculations provided a reliable means of predicting the properties of dyes, which could help in the design of more efficient and novel dyes. To verify the practicability of the dyes, two dyes with excellent photophysical properties (large Stokes shift, high polarity-viscosity sensitivity, good biocompatibility) were selected as fluorescent probes for visualization of LDs and two-color imaging of LDs and lysosomes. Cell imaging showed that NapPA-LDs and NapPA-LDs-Lyso serve as excellent imaging tools to monitor the dynamic changes, movements, and behaviors of LDs and lysosomes in real time. Notably, NapPA-LDs-Lyso held promise as a potential tool to study the interaction between LDs and lysosomes.

π-Extended BTD Derivatives: Synthesis, Photophysical Properties, and Applications in Biological Systems Imaging for Discriminating Living and Dead Cells.

Here, π-Extended BTD derivatives were successfully synthesized by Heck coupling reaction, which exhibited the the advantages of simplicity and efficiency, wild substrate scope, easily available substrates and high yield. The fluorescent probe PEG-BTDAr targeting LDs was successfully prepared by the nucleophilic substitution reaction between the Heck coupling reaction product 3 h and Amino polyethylene glycol monomethyl ether (Mn=2000). PEG-BTDAr exhibited the advantages of high selectivity, good stability and pH resistance. The use of PEG as a substrate gave PEG-BTDAr good biocompatibility. It was worth mentioning that PEG-BTDAr could not only track LDs in cells under different physiological conditions, but also distinguish between living and dead cells in biological systems.

Viscosity & SO2-sensitive dual colorimetric effect fluorescent sensor enabled imaging detection within plant onion and biological system.

The biological microenvironment includes important parameters such as viscosity, polarity, temperature, oxygen content and pH. In particular, abnormal cell viscosity is associated with the development of major diseases. Sulphur dioxide (SO2) serves not only as an essential atmospheric pollutant but also an influential signalling molecule in biological cells, predisposing individuals to increased respiratory disease. In this work, we designed and synthesized a novel fluorescent probe CouCN-V&S with dual response to micro environmental viscosity and SO2. The probe monitored viscosity and SO2 separately through dual emission channels with a difference of 135 nm. The probe responded sensitively to SO2 (<1s) and exhibited satisfactory immunity to interference and pH stability. The probe was successfully applied to imaging cellular, intra-zebrafish viscosity and SO2 changes. Interestingly, we took onion epidermal cells as model and explored the capability of probe CouCN-V&S to image SO2 in plant cells for the first time.

[Corrigendum] Knockdown of HOXA10 reverses the multidrug resistance of human chronic mylogenous leukemia K562/ADM cells by downregulating P­gp and MRP­1.

Following the publication of the above article, an interested reader drew to the authors' attention that, in Fig. 2 on p. 1408, the microscopic images shown for the light scope images (upper row) and the green fluorescence images (lower row) appeared to be overlapping, such that these images appeared to have been derived from the same original sources even though they were intended to portray the results from differently performed experiments. After having re­examined their figures, the authors realized that this figure was assembled incorrectly. The revised version of Fig. 2, showing the correct data for all four experimental panels, is shown below. Note that the errors made during the assembly of these figures did not affect the overall conclusions reported in the paper. All the authors agree with the publication of this corrigendum, and are grateful to the Editor of International Journal of Molecular Medicine for allowing them the opportunity to publish this. They also apologize to the readership for any inconvenience caused. [International Journal of Molecular Medicine 37: 1405­1411, 2016; DOI: 10.3892/ijmm.2016.2539].

Reduced platelet 5-HT content is associated with rest tremor in Parkinson's disease.

INTRODUCTION: Parkinson's disease (PD) is highly heterogeneous in manifestations and pathogenesis. Serotonergic neurotransmitter system dysfunction is frequently implicated in PD tremor. Serotonin (5-HT) content in platelets is highly correlated with that in cerebrospinal fluid. In this study, we aimed to understand whether and how platelet 5-HT content reflects tremor in PD. METHOD: A total of 139 Chinese PD patients met with inclusion criteria were recruited. Motor and non-motor scores, and disease severity were evaluated. Patients were classified into subtypes of tremor-dominant (TD) and non-tremor-dominant (NTD). Peripheral platelets were isolated, and platelet 5-HT levels were measured. RESULTS: Platelet 5-HT content was lower in PD patients of TD subtype than in NTD subtype. Multifactor risk analysis showed that this lower content was independently associated with the TD phenotype. Platelet 5-HT level was inversely correlated with total tremor score, rest tremor amplitude score, rest tremor constancy score, and index of rest tremor, but not with postural tremor score, and kinetic tremor score. CONCLUSION: The cross-sectional study demonstrates that reduced platelet 5-HT content is associated with PD rest tremor. Our results support the involvement of serotonergic disturbance in PD rest tremor and indicate that 5-HT reduction can be manifested in peripheral platelets.