MS3 Imaging Enables the Simultaneous Analysis of Phospholipid C═C and sn-Position Isomers in Tissues.

Mass spectrometry (MS) imaging of lipids in tissues with high structure specificity is challenging in the effective fragmentation of position-selective structures and the sensitive detection of multiple lipid isomers. Herein, we develop an MS3 imaging method for the simultaneous analysis of phospholipid C═C and sn-position isomers by on-tissue photochemical derivatization, nanospray desorption electrospray ionization (nano-DESI), and a dual-linear ion trap MS system. A novel laser-based sensing probe is developed for the real-time adjustment of the probe-to-surface distance for nano-DESI. This method is validated in mouse brain and kidney sections, showing its capability of sensitive resolving and imaging of the fatty acyl chain composition, the sn-position, and the C═C location of phospholipids in an MS3 scan. MS3 imaging of phospholipids has shown the capability of differentiation of cancerous, fibrosis, and adjacent normal regions in liver cancer tissues.

CSDR Coupling with Exo III for Ultrasensitive Electrochemistry Determination of miR-145.

Recently, miRNAs have become a promising biomarker for disease diagnostics. miRNA-145 is closely related to strokes. The accuracy determination of miRNA-145 (miR-145) in stroke patients still remains challenging due to its heterogeneity and low abundance, as well as the complexity of the blood matrix. In this work, we developed a novel electrochemical miRNA-145 biosensor via subtly coupling the cascade strand displacement reaction (CSDR), exonuclease III (Exo III), and magnetic nanoparticles (MNPs). The developed electrochemical biosensor can quantitatively detect miRNA-145 ranging from 1 × 102 to 1 × 106 aM with a detection limit as low down as 100 aM. This biosensor also exhibits excellent specificity to distinguish similar miRNA sequences even with single-base differences. It has been successfully applied to distinguish healthy people from stroke patients. The results of this biosensor are consistent with the results of the reverse transcription quantitative polymerase chain reaction (RT-qPCR). The proposed electrochemical biosensor has great potential applications for biomedical research on and clinical diagnosis of strokes.

The fluorescent aptasensor based on CRISPR-Cas12a combined with TdT for highly sensitive detection of cocaine.

Ultrasensitive and specific detection of cocaine is of great significance for monitoring cocaine abuse. Herein, a fluorescent aptasensor via coupling CRISPR-Cas12a, with magnetic nanoparticles (MNPs), split-aptamer, and terminal deoxynucleotidyl transferase (TdT), was developed for the detection of cocaine. In short, the complete cocaine aptamer is split into two parts, one is modified on magnetic nanoparticles (MNPs) and the other is free. The presence of cocaine will mediate the binding of these two segments. Then TdT will mediate the extension to form an ultra-long sequence that can bind with multiple CRISPR-Cas12a resulting in the trans-cleavage activity of CRISPR-Cas12a being triggered. Thence, the DNA reporter which is bi-labeled with fluorophore and quencher is cleaved resulting in the generation of a fluorescence signal. The developed fluorescent aptasensor realizes the detection of cocaine with excellent sensitivity and specificity. The detection limit is low down to 33 pM, and the linear range is from 330 to 1.65 × 105 pM. Most importantly, this fluorescent aptasensor can be successfully applied to the determination of cocaine in human plasma samples.

CRISPR/Cas12a Coupling with Magnetic Nanoparticles and Cascaded Strand Displacement Reaction for Ultrasensitive Fluorescence Determination of Exosomal miR-21.

Exosomal MicroRNA-21 (miRNA-21, miR-21) is significantly up-regulated in blood samples of patients with lung cancer. Exosomal-derived miR-21 can be used as a promising biomarker for the early diagnosis of lung cancer. This paper develops a fluorescent biosensor based on the combination of magnetic nanoparticles (MNPs), cascade strand displacement reaction (CSDR) and CRISPR/Cas12a to detect the exosomal miR-21 from lung cancer. The powerful separation performance of MNPs can eliminate the potential interference of matrix and reduce the background signal, which is very beneficial for the improvement of specificity and sensitivity. The CSDR can specifically transform one miR-21 into plenty of DNA which can specifically trigger the trans-cleavage nuclease activity of Cas12a, resulting in the cleavage of ssDNA bi-labeled with fluorescent and a quencher. Under the optimized experimental conditions, the developed fluorescence biosensor exhibited high sensitivity and specificity towards the determination of exosomal-derived miR-21 with a linear range from 10 to 1 × 105 fM and a low detection limit of about 0.89 fM. Most importantly, this method can be successfully applied to distinguish the exosomal miR-21 from the lung cancer patients and the healthy people.

Determination of miRNA derived from exosomes of prostate cancer via toehold-aided cyclic amplification combined with HRP enzyme catalysis and magnetic nanoparticles.

MicroRNAs (miRNAs) play a significant role in tumorigenesis and tumor development. Exosomal microRNA-141 (miRNA-141, miR-141) has been reported to be overexpressed in prostate cancer (PCa) and has become a potential biomarker for the diagnosis of PCa. Herein, a novel fluorescent biosensor based on toehold-aided cyclic amplification combined with horseradish peroxidase (HRP) enzyme catalysis and magnetic nanoparticles (MNPs) was designed for determination of the exosomes-derived microRNA-141 (miRNA-141, miR-141). The synergy of HRP enzyme catalysis and toehold mediated strand display reaction (TSDR) increase the sensitivity of the method, and the good separation ability of MNPs ensures the specificity of the method. Therefore, under the optimized experimental conditions, the highly sensitive and specific detection of miRNA-141 can be realized, and the detection limit is as low as 10 fM. More importantly, the biosensor successfully determinates the exosomal miR-141 in the plasma of patients with PCa.

Highly selective synthesis of D-amino acids via stereoinversion of corresponding counterpart by an in vivo cascade cell factory.

BACKGROUND: D-Amino acids are increasingly used as building blocks to produce pharmaceuticals and fine chemicals. However, establishing a universal biocatalyst for the general synthesis of D-amino acids from cheap and readily available precursors with few by-products is challenging. In this study, we developed an efficient in vivo biocatalysis system for the synthesis of D-amino acids from L-amino acids by the co-expression of membrane-associated L-amino acid deaminase obtained from Proteus mirabilis (LAAD), meso-diaminopimelate dehydrogenases obtained from Symbiobacterium thermophilum (DAPDH), and formate dehydrogenase obtained from Burkholderia stabilis (FDH), in recombinant Escherichia coli. RESULTS: To generate the in vivo cascade system, three strategies were evaluated to regulate enzyme expression levels, including single-plasmid co-expression, double-plasmid co-expression, and double-plasmid MBP-fused co-expression. The double-plasmid MBP-fused co-expression strain Escherichia coli pET-21b-MBP-laad/pET-28a-dapdh-fdh, exhibiting high catalytic efficiency, was selected. Under optimal conditions, 75 mg/mL of E. coli pET-21b-MBP-laad/pET-28a-dapdh-fdh whole-cell biocatalyst asymmetrically catalyzed the stereoinversion of 150 mM L-Phe to D-Phe, with quantitative yields of over 99% ee in 24 h, by the addition of 15 mM NADP+ and 300 mM ammonium formate. In addition, the whole-cell biocatalyst was used to successfully stereoinvert a variety of aromatic and aliphatic L-amino acids to their corresponding D-amino acids. CONCLUSIONS: The newly constructed in vivo cascade biocatalysis system was effective for the highly selective synthesis of D-amino acids via stereoinversion.

Polysaccharides from TCM herbs exhibit potent anti-obesity effect by mediating the community structure of gut microbiota.

High-calorie food intake and unhealthy lifestyle have considerably raised the incidence of obesity. The gut microbiota is associated with metabolic disorders which promote excessive accumulation of fat, elicit host systemic, low-grade chronic inflammation, and insulin resistance. These features make gut microbiota a promising target for the prevention and intervention of obesity. Herbal polysaccharides in TCM are uneasy to digest by the host, but can be decomposed and utilized by the intestinal flora as the carbon source to mediate bacterial composition. In this review, we are describing the therapeutic effect of polysaccharides on the imbalanced structure of gut microbiota and its metabolites, and discuss the research progress that has been made to unravel the underlying mechanism by which polysaccharides of TCM inhibit the onset and development of obesity.

"Gut-skin"axis: understanding psoriasis from the gut.

Background: The exact pathogenesis of psoriasis is complex, and scholars use the intestinal mucosal immunity as an entry point to analyze the important role of the intestine in the pathogenesis of psoriasis. Traditional Chinese medicine treats psoriasis from the intestine based on the theory that "the lung governs the fur" and "the Interior-Exterior Relationship Between the Lung and Large Intestine". Based on this understanding, this paper puts forward the idea of understanding psoriasis from the "gut-skin" axis. Objective: Based on the "gut-skin" axis to explore the pathogenesis of psoriasis from the intestines, and open up new ideas for research and development of new drugs for psoriasis. Method: Collect literature on the treatment of psoriasis from the perspective of the intestine and "gut-skin" axis; then, use Western medicine's intestinal pathogenesis, Traditional Chinese Medicine (TCM) theory and examples of TCM treatment are demonstrated; finally, the treatment of psoriasis from the "gut-skin" axis is summarized. Results: Western medicine has not carried out treatment of psoriasis involving the intestinal tract. In-depth research and clinical applications based on the "gut-skin" axis are still needed. The effective rate of treating psoriasis by TCM has been as high as 90%, but the mechanism research is relatively scarce. Conclusion: The construction of the "gut-skin" axis mechanism is consistent with TCM theories, and is consistent with modern scientific connotations as well.

Efficacy of extended versus standard lymphadenectomy in pancreatoduodenectomy for pancreatic head adenocarcinoma. An update meta-analysis.

BACKGROUND: Surgical resection is the only possible cure for pancreatic cancer, it remains controversial whether extend lymphadenectomy in pancreatoduodenectomy (EPD) is better than standard lymphadenectomy in pancreatoduodenectomy (SPD). The aim of this study was to compare the efficacy of EPD with SPD for pancreatic head adenocarcinoma. METHODS: A specific search of online databases including PubMed, Web of Science, Embase, and Cochrane library was conducted from January 1990 to October 2018. Relative perioperative outcomes were synthesized. Single-arm meta-analysis was also performed. RESULTS: A total of eight studies involving 687 (342 vs 345) patients were included for analysis in our study. The number of lymph nodes harvested [24.54 vs 13.29; weighted mean difference (WMD) -10.69, P = 0.000], operative time (469.84 min vs 354.85 min; WMD -99.09, P = 0.000), and diarrhea (postoperative three months) [45.1% vs 18.2%; odds radio (OR) 0.20, P = 0.014] were significantly higher in patients who underwent EPD than SPD. The perioperative complications (35% vs 28.8%; OR 0.79, P = 0.186), tumor size (3.27 cm vs 3.248 cm; WMD -0.11, P = 0.256), lymph node metastasis (66% vs 55.9%; OR 0.71, P = 0.105), and positive margin (10.4% vs 11.3%; OR 1.28, P = 0.392) were no significant differences between EPD group and SPD group. Extended lymphadenectomy in pancreatoduodenectomy dose not contribute to the overall survival of patients with adenocarcinoma of the pancreatic head [hazard ratio (HR) 0.95; 95% CI 0.78-1.15; P = 0.61]. CONCLUSION: The update meta-analysis shows that EPD failed to improve the overall survival, may even lead to increased morbidity.

An electrochemical aptasensing platform for carbohydrate antigen 125 based on the use of flower-like gold nanostructures and target-triggered strand displacement amplification.

An electrochemical aptasensing method is described for the determination of the biomarker CA125. It combines aptamer recognition and target-triggered strand displacement amplification. Flower like gold nanostructures were electrodeposited on a screen-printed carbon electrode to increase the sensor surface, to assemble more toehold-containing hairpin probe 1 (Hp1), and to improve the accessibility for DNA strands. Under the optimal conditions, this assay has a linear response in the 0.05 to 50 ng•mL-1 CA125 concentration range, with a low detection limit of 5.0 pg•mL-1. This method is specific and stable. It was successfully applied to the detection of CA125 in spiked biological samples, with recoveries between 82.5% and 104.1%. Graphical abstract.

[A Simple Medical Research Microdevice for Analyzing Three-dimensional Migration of Tumor Cells in Vitro].

Objective To develop and verify a medical microdevice for analyzing the three-dimensional(3D)migration of tumor cells in extracellular matrix. Methods The mold of the microdevice was made by precision machining,and then the medical microdevice based on polydimethylsiloxane(PDMS)-glass was obtained by PDMS casting,moulding,and bonding.During the analysis,the suspension of tumor cells and matrigel were mixed and then added into the migration channel of microdevice,and the controllable migration of tumor cells in matrigel was induced by establishing chemokine concentration gradient on both sides of the migration channel.Meanwhile,the migration process of tumor cells was recorded with the live cell dynamic imaging device. Results Breast cancer cell line MCF-7 was taken as an example to verify the feasibility of the microdevice to control and dynamically monitor the 3D migration process of tumor cells in vitro.Qualitative analysis of imaging data showed that the migration of MCF-7 cell lines in matrigel was determined by the concentration gradient distribution direction of chemokine and presented as the amoeboid-like migration mode.The proportion and migration velocity of MCF-7 cells could be quantified by the quantitative analysis of cell migration process.The inhibition ability of matrix metalloproteinase inhibitors(Batimastat)and adenosine triphosphatase inhibitors(Blebbistation)on the 3D migration behavior of MCF-7 cells was found to be different.Conclusion This device can be used for in-depth analysis of tumor cell migration and its mechanism and for evaluating the efficacy of anti-metastatic drugs.

Rapid Determination of Saponins in the Honey-Fried Processing of Rhizoma Cimicifugae by Near Infrared Diffuse Reflectance Spectroscopy.

OBJECTIVE: A model of Near Infrared Diffuse Reflectance Spectroscopy (NIR-DRS) was established for the first time to determine the content of Shengmaxinside I in the honey-fried processing of Rhizoma Cimicifugae. METHODS: Shengmaxinside I content was determined by high-performance liquid chromatography (HPLC), and the data of the honey-fried processing of Rhizoma Cimicifugae samples from different batches of different origins by NIR-DRS were collected by TQ Analyst 8.0. Partial Least Squares (PLS) analysis was used to establish a near-infrared quantitative model. RESULTS: The determination coefficient R² was 0.9878. The Cross-Validation Root Mean Square Error (RMSECV) was 0.0193%, validating the model with a validation set. The Root Mean Square Error of Prediction (RMSEP) was 0.1064%. The ratio of the standard deviation for the validation samples to the standard error of prediction (RPD) was 5.5130. CONCLUSION: This method is convenient and efficient, and the experimentally established model has good prediction ability, and can be used for the rapid determination of Shengmaxinside I content in the honey-fried processing of Rhizoma Cimicifugae.

9,19-Cycloartenol glycoside G3 from Cimicifuga simplex regulates immune responses by modulating Th17/Treg ratio.

Cimicifuga simplex is a medicinal herb which has a wide range of biological activities. We isolated seven 9,19-cycloartenol glycosides from the roots of C. simplex, and among the glycosides, G3 exhibited the strongest inhibitory effect on immune responses, including suppressing the differentiation of CD4+ T cells and directly suppressing the cytokine-induced JAK/STAT signaling pathways. In the IL-23-induced mouse ear model of skin disease, G3 repressed disease development by inhibiting the expression of pro-inflammatory mediators in murine ear skin. Moreover, G3 affected the maturation of DCs in vitro, thereby inducing T cell differentiation, resulting in an increased Treg phenotype and decreased Th17 phenotype. This study provides new evidence that G3 might ameliorate chronic inflammatory skin diseases by suppressing pathogenic CD4+ T cell differentiation and the IL-17+RORγt+/IL-10+FoxP3+ ratio. These findings suggest that G3 might mediate the therapeutic effects observed in psoriasis patients following treatment with C. simplex.

miRNA-124 modulates lung carcinoma cell migration and invasion.

OBJECTIVES: Lung cancer remains the leading cause of cancer-related mortality worldwide. Recently, accumulating studies have evidenced that microRNAs (miRNAs) contribute to the carcinogenesis of lung cancer through acting as either oncogenes or tumor suppressors. The purpose of our study was to investigate the functional role of miR-124 in lung cancer. METHODS: The expression of miR-124 was assessed by real-time RT-PCR in non-small cell lung cancer (NSCLC) tissues in comparison to its adjacent normal tissues. After transfection with miR-124 Mimics or negative controls into A549 cells, migration and invasion assays, apoptosis, and cell viability were evaluated. Luciferase reporter assay and RT-PCR were performed to explore whether zinc finger e-box binding homeobox 1 (ZEB1) was a target of miR-124. Further, the effects of miR-124 Mimic on migration and invasion were assessed after overexpression of ZEB1. RESULTS: MiR-124 expression was significantly down-regulated in NSCLC tissues compared to the normal tissue. In in-vitro study, overexpression of miR-124 in A549 cells suppressed cell migration and invasion activity, decreased expression of vimentin, but increased expression of E-cadherin and induced apoptosis. Luciferase reporter assay ensured that ZEB1 was a direct target of miR-124 and was negatively regulated by miR-124. Overexpression of ZEB1 could reverse the effect of miR-124 Mimic on the migration and invasion of the cells. CONCLUSION: The results suggests that miR-124 inhibits lung cancer cell migration and invasion through suppressing epithelial-mesenchymal transition (EMT) and inducing apoptosis of the lung cancer cells.

[Effects of hypoxia inducible factor-2α on promoting angiogenesis of residual hepatocellular carcinoma after high-intensity focused ultrasound ablation].

OBJECTIVE: To investigate the dynamic features of angiogenesis in residual tumors after high intensity focused ultrasound (HIFU),and to determine the temporal effect and mechanism of hypoxia inducible factor-2 alpha (HIF-2a) in the angiogenic process of residual tumors. METHODS: Xenograft tumors of HepG2 cells were generated by subcutaneously inoculating athymic BALB/c nu/nu mice with the hepatoma cells.About 30 days after inoculation,all mice (except in the control group) were treated by HIFU and assigned randomly to the following 7 groups according to various time intervals post-treatment:1st,3rd,5th day and 1st,2nd,3rd,4th week when the residual tumor tissues were obtained from the experimental groups.Protein levels of HIF-2a and vascular growth factor A (VEGF-A) were quantified by immunohistochemistry and western blotting,and mRNA levels were measured by (real-time quantitative) qPCR. Microvascular density (MVD) was calculated by counting the CD31-positive vascular endothelial cells identified by means of an immunohistochemical staining method. RESULTS: Compared with results from the control group,the protein and mRNA levels of HIF-2a expression reached the highest level in the experimental mice at the 2nd week (P=0.000 and P < 0.01 respectively),and were decreased thereafter(3rd week and 4th week, P=0.000 and P < 0.05).VEGF-A expression in the residual tumor tissues group that received HIFU was significantly decreased,compared with the control group,at all time points uPto 1 week (all P=0.000 and P < 0.01),but the levels increased compared to controls in the 2nd through 4th week (all P=0.000, P < 0.05). Similar results were obtained for MVD. CONCLUSION: HIFU treatment can inhibit angiogenesis in residual hepatoma tissues in the short-term (1 to 2 weeks post-treatment) in mice with hepatocellular carcinoma,but can promote angiogenesis overtime (2 to 4 weeks post-treatment); the angiogenic process may involve the HIF-2α/VEGFA pathway.

New 9,19-cycloartenol glycosides isolated from the roots of Cimicifuga simplex and their anti-inflammatory effects.

Two new cycloartenol triterpene saponins, 3ß,16α-dihydroxy-12-acetoxy-16,22-cyclo-23-ketone-24R,25-epoxy-cycloartane-3-O-ß-D-galactopyranoside (1), 3ß,16α-dihydroxy-12-acetoxy-16,22-cyclo-23-ketone-24R,25-epoxy-cycloartane-7-ene-3-O-ß-D-xylopyranoside (2), were isolated from the ethyl acetate soluble fraction of the roots of Cimicifuga simplex Wormsk. Their structures were established by detailed spectroscopic analysis, including extensive 2D NMR data. Their anti-proinflammatory activities were also carried out by LPS-stimulated IL-6, IL-23 and TNF-α genes expression in RAW cells in vitro using Q-PCR method.

Untargeted metabolomics reveals intervention effects of wine-processed Schisandra chinensis polysaccharide on Alzheimer's disease mice.

Schisandra chinensis (Turcz.) Baill (SC) is a traditional sedative in China, with wide applications for treating various neurological disorders. Its polysaccharide component has been gaining increased attention for its potential in nerve protection. While raw SC is the primary focus of current research, its processed products are primarily utilized as clinical medicines. Notably, limited research exists on the mechanisms underlying the effects of wine-processed Schisandra chinensis polysaccharide (WSCP) in Alzheimer's Disease (AD). Therefore, this study seeks to assess the therapeutic impact of WSCP on AD mice and investigate the underlying mechanisms through biochemical and metabolomics analyses. The results demonstrate that WSCP exerts significant therapeutic effects on AD mice by enhancing learning and memory abilities, mitigating hippocampal neuronal damage, reducing abnormal amyloid-beta (Aß) deposition, and attenuating hyperphosphorylation of Tau. Biochemical analysis revealed that WSCP can increase SOD content and decrease MDA, IL-6, and TNF-α content in AD mice. Furthermore, serum metabolomic results showed that WSCP intervention can reverse metabolic disorders in AD mice. 43 endogenous metabolites were identified as potential biomarkers for WSCP treatment of AD, and the major metabolic pathways were Ala, Glu and Asp metabolism, TCA cycle. Overall, these findings will provide a basis for further development of WSCP.

Correction: Immunoassay-aptasensor for the determination of tumor-derived exosomes based on the combination of magnetic nanoparticles and hybridization chain reaction.

[This corrects the article DOI: 10.1039/D0RA10159A.].