Corydecusines A-H, new phthalideisoquinoline hemicetal alkaloids from the bulbs of Corydalis decumbens inhibit Tau pathology by activating autophagy mediated by AMPK-ULK1 pathway.

Twelve phthalideisoquinoline hemiacetal alkaloids including eight new ones (1-8) and one natural alkaloid characterized by an aziridine moiety with unassigned NMR data (9), were isolated and identified from the bulbs of Corydalis decumbens. Their structures were established by comprehensive analyses of HRESIMS, NMR, X-ray crystallography, and ECD analyses. The unambiguously established structures of the phthalideisoquinoline hemiacetal alkaloids indicated that the absolute configurations of C-1, C-9, and C-7' were confusable only relied on coupling constants. A summary of their ECD spectra was concluded and provided an insight for C-1, C-9, and C-7' absolute configuration assignment. These new compounds were evaluated to induce autophagy flux through flow cytometry analysis. Moreover, compounds 2 and 6 could significantly induce autophagy and inhibit Tau pathology by AMPK-ULK1 pathway activation, which provided an avenue for anti-AD lead compounds discovery.

Enhancing the Production of Pinene in Escherichia coli by Using a Combination of Shotgun, Product-Tolerance and I-SceI Cleavage Systems.

Tolerance breeding through genetic engineering, sequence and omics analyses, and gene identification processes are widely used to synthesize biofuels. The majority of related mechanisms have been shown to yield endogenous genes with high expression. However, the process was time-consuming and labor-intensive, meaning there is a need to address the problems associated with the low-throughput screening method and significant time and money consumption. In this study, a combination of the limit screening method (LMS method) and product-tolerance engineering was proposed and applied. The Escherichia coli MG1655 genomic DNA library was constructed using the shotgun method. Then, the cultures were incubated at concentrations of 0.25%, 0.5%, 0.75% and 1.0% of pinene with different inhibitory effects. Finally, the genes acrB, flgFG, motB and ndk were found to be associated with the enhanced tolerance of E. coli to pinene. Using the I-SceI cleavage system, the promoters of acrB, flgFG and ndk genes were replaced with P37. The final strain increased the production of pinene from glucose by 2.1 times.

A photostable Si-rhodamine-based near-infrared fluorescent probe for monitoring lysosomal pH during heat stroke.

Heat stroke is a symptom of hyperthermia with a temperature of more than 40 °C, which usually leads to all kinds of physical discomfort and even death. It is necessary to study the mechanism of action of heat stroke on cells or organelles (such as cytotoxicity of heat) and the processes of cells or organelles during heat stroke. Recent studies have shown that there is a certain correlation between heat stroke and lysosome acidity. In order to clarify their relationship, Lyso-NIR-pH, a photostable Si-rhodamine-based near-infrared fluorescent probe, was developed for sensing pH changes in lysosomes during heat stroke in this paper. For Lyso-NIR-pH, a morpholine group is employed as the lysosome-targeting unit and a H+-triggered openable deoxylactam is employed as the response unit to pH. Lyso-NIR-pH can detect pH with a high selectivity and a sensitivity, and its pKa is 4.63. Lyso-NIR-pH also has outstanding imaging performances, such as excellent lysosome-targeting ability, low autofluorescence and photostable fluorescence signal, which are in favor of long-term imaging of pH with accurate fluorescence signals. Moreover, we successfully applied Lyso-NIR-pH to monitor lysosomal pH increases induced by chloroquine and apoptosis in live cells. Finally, we successfully applied Lyso-NIR-pH for monitoring changes of lysosomal pH during heat stroke. These results confirmed that Lyso-NIR-pH is a powerful tool to monitor pH change in lysosomes and study its possible effects.

A mitochondria-targetable two-photon fluorescent probe with a far-red to near-infrared emission for sensing hypochlorite in biosystems.

Hypochlorite (ClO-), one of reactive oxygen species (ROS), is closely related with many physiological and pathological processes. Especially as one of cellular reactive oxygen species in mitochondria, ClO- can induce mitochondrial permeability, which leads to apoptosis. Thus, developing an effective method which is able to sense ClO- in mitochondria is important. Although fluorescent probe has become a powerful tool for imaging ClO- in mitochondria, most of them suffered from phototoxicity to biosamples, autofluorescence, and photobleaching phenomenon due to their short-wavelength excitations and emissions. Based on advantages of two-photon fluorescent probe and far-red to NIR fluorescent probe, a mitochondria-targetable two-photon fluorescent probe with a turn-on signal in far-red to NIR region, Mito-TP-ClO, was developed for ClO- in this paper. Mito-TP-ClO is consisted of a triphenylphosphonium cations as a mitochondria-targetable unit and a structure of dibenzoylhydrazine as a response unit to ClO-. Mito-TP-ClO exhibited a high sensitivity and a high selectivity to ClO-, with a linear range from 6.0 × 10-8 to 1.0 × 10-5 M and a detection limit of 2.5 × 10-8 M. Due to its large two-photon cross section (267 GM) and far-red to NIR emission, Mito-TP-ClO exhibits excellent performances including low autofluorescence, photostable fluorescence signal, and deep tissue penetration (230 µM). Moreover, Mito-TP-ClO was successfully used to detect endogenous ClO- in bacteria-infected cells and inflammatory mouse model, which confirmed that Mito-TP-ClO is a powerful tool to monitor ClO- in mitochondria and study on effects of hypochlorite on mitochondria.

A near-infrared fluorescent probe based on photostable Si-rhodamine for imaging hypochlorous acid during lysosome-involved inflammatory response.

Hypochloric acid (HClO) is mainly distributed in acidic lysosomes of phagocytes and closely associated with numerous physiological and pathological processes, especially inflammatory response. Fluorescent probe has become an important tool for imaging HClO in lysosomes, but suffered from interference from autofluorescence in vivo, phototoxicity to biosamples and photobleaching phenomenon due to their short-wavelength excitation and emission. Unfortunately, up to now, no near-infrared (NIR) lysosome-targetable fluorescent probe has been reported for imaging HClO. In this paper, a near-infrared fluorescent probe Lyso-NIR-HClO for imaging lysosomal HClO was reported for the first time. Lyso-NIR-HClO based on Si-rhodamine is consisted of a morpholine unit as a lysosome-targetable group and a HClO-mediated cyclization reaction site as a response group, which was applied for highly selective and sensitive detection and imaging for endogenous and exogenous HClO in lysosomes, with a linear range from 5.0 × 10-8 to 1.0 × 10-5 M and a detection limit of 2.0 × 10-8 M in vitro. Attributed to NIR emission and excellent photostability of Si-rhodamine, Lyso-NIR-HClO exhibits excellent performances in vivo, such as low interference from intracellular autofluorescence, stable and persistent fluorescence signal and good tissue penetration, which are in favor of accurate, time-lapse and long-term imaging for HClO. Finally, we applied the probe Lyso-NIR-HClO to visualize endogenous HClO during lysosome-involved inflammatory response including bacteria-infected cells and inflamed mouse model with satisfactory results. The above results proved that Lyso-NIR-HClO would be a potentially useful tool for the study of biological functions and pathological roles of HClO in lysosomes, especially role of lysosome in the inflammatory response.

G-quadruplex fluorescent probe-mediated real-time rolling circle amplification strategy for highly sensitive microRNA detection.

Real-time PCR has revolutionized PCR from qualitative to quantitative. As an isothermal DNA amplification technique, rolling circular amplification (RCA) has been demonstrated to be a versatile tool in many fields. Development of a simple, highly sensitive, and specific strategy for real-time monitoring of RCA will increase its usefulness in many fields. The strategy reported here utilized the specific fluorescence response of thioflavin T (ThT) to G-quadruplexes formed by RCA products. Such a real-time monitoring strategy works well in both traditional RCA with linear amplification efficiency and modified RCA proceeded in an exponential manner, and can be readily performed in commercially available real-time PCR instruments, thereby achieving high-throughput detection and making the proposed technique more suitable for biosensing applications. As examples, real-time RCA-based sensing platforms were designed and successfully used for quantitation of microRNA over broad linear ranges (8 orders of magnitude) with a detection limit of 4 aM (or 0.12 zmol). The feasibility of microRNA analysis in human lung cancer cells was also demonstrated. This work provides a new method for real-time monitoring of RCA by using unique nucleic acid secondary structures and their specific fluorescent probes. It has the potential to be extended to other isothermal single-stranded DNA amplification techniques.

[Association of rearing patterns with diet and temperament traits among infants in urban areas].

OBJECTIVE: To explore the effects of rearing patterns on diet and temperament traits among infants in urban areas. METHODS: A total of 480 25-30-month-old infants were randomly selected from the birth cohort in Hefei Maternal and Child Health Care Center in 2008. A household survey was conducted using China Toddler Temperament Scale (CTTS), Dietary Characteristics Questionnaire and Family Environment Questionnaire. RESULTS: Of the 430 surveyed households, there were three main rearing patterns including parents rearing pattern (Group A), grandparents rearing pattern (Group B) and joint rearing pattern (Group C), accounting for 33.0%, 21.2% and 45.8%, respectively. Infants in Group A tended to adopt processed food pattern, with poor rhythmicity and adaptability; infants in Group B tended to adopt fruit, vegetable, and cereals-based food pattern, with relatively poor rhythmicity; infants in Group C tended to adopt aquatic products and fruit/vegetable-based food pattern, with good rhythmicity and adaptability. Linear regression model showed that infants who consumed more aquatic products, high-protein food, and fruits/vegetables had more positive temperamental traits, whereas infants who consumed more processed foods had more negative temperamental traits. CONCLUSIONS: A joint rearing pattern may be a favorable rearing style for infants aged 25-30 months in urban areas in terms of diet and temperament traits.

[Impacts of gestational weight gain on offspring weight and obesity: a 2-year follow up study].

OBJECTIVE: To evaluate the impacts of maternal weight gain during pregnancy on offspring weight and obesity from birth to 24 months of age. METHODS: The information on maternal pre-pregnancy body mass index (BMI), gestational weight gain and demographic characteristics were collected from 317 pregnant women. The information on offspring weight, BMI and breastfeeding data was obtained from various follow-up examinations from 0 to 24 months of age. RESULTS: The logistic regression analysis showed that excessive gestational weight gain resulted in an increased risk of obesity in children at age of 6 months (adjusted RR=3.56, 95% CI:1.31-8.35) and 9 months (adjusted RR=2.87, 95% CI: 1.04-3.28) after adjustment for potential confounding factors. The linear regression model showed that there were significant correlations between gestational weight gain and Z score of weight in offsprings at birth (ß=0.032, 95% CI: 0.008-0.057), 3 months (ß=0.037, 95% CI: 0.013-0.062), 6 months (ß=0.043, 95% CI: 0.017-0.068), 9 months (ß=0.038, 95% CI: 0.013-0.063) and 12 months (ß=0.034, 95% CI: 0.009-0.059), but not at 18 months and 24 months. CONCLUSIONS: Excessive gestational weight gain may affect offspring weight and increase the risk of obesity in children from birth to 12 months of age. During their second year of life, this effect will temporarily disappear.