Rapid one-pot isothermal amplification reassembled of fluorescent RNA aptamer for SARS-CoV-2 detection.

The outbreak of SARS-CoV-2 poses a serious threat to human life and health. A rapid nucleic acid tests can effectively curb the spread of the disease. With the advantages of fluorescent RNA aptamers, low background and high sensitivity. A variety of fluorescent RNA aptamer sensors have been developed for the detection of nucleic acid. Here, we report a hypersensitive detection platform in which SARS-CoV-2 initiates RTF-EXPAR to amplify trigger fragments. This activation leads to the reassembled of the SRB2 fluorescent RNA aptamer, restoring its secondary structure for SR-DN binding and turn-on fluorescence. The platform completes the assay in 30 min and all reactions occur in one tube. The detection limit is as low as 116 aM. Significantly, the platform's quantitative analyses were almost identical to qPCR results in simulated tests of positive samples. In conclusion, the platform is sensitive, accurate and provides a new protocol for point-of-care testing of viruses.

[Discussion on discipline of herbalism].

Since the emergence of the term "materia medica", scholars have proposed different opinions on its concept. This term has been used to refer to traditional Chinese medicines, or medical books, or traditional pharmacology. Due to the differences in the concept of materia medica, scholars also have controversies about the concept of herbalism. Herbalism is usually understood as traditional Chinese pharmacology. After years of evolution, the term "herbalism" has now possessed the characteristics of an independent discipline, which can be defined as an applied basic discipline that comprehensively utilizes traditional and modern technological methods to study the formation, development, and changes of traditional pharmacology and reveal the basic theories and application laws of traditional medicine. At present, the research content of herbalism mainly includes three aspects: materia medica history, materia medica literature, and traditional pharmacology. This study explores the disciplinary concepts and main research content of herbalism based on a systematic review of the literature about the concepts of materia medica and herbalism, with the aim of attracting more attention to promote the establishment and development of the discipline of herbalism.

Classification and minimally invasive management of ureteroileal bladder anastomotic stricture after radical cystectomy / 中华泌尿外科杂志

Objective:To discuss the classification and treatment of ureteroileal anastomotic stricture (UAS) after radical cystectomy.Methods:The clinical data of 34 patients with UAS after radical cystectomy in the Department of Urology of Tongji Hospital from January 2017 to January 2022 were reviewed and analyzed. There were 25 males and 9 females. The average age was (66.3±7.7)years, including 2 cases of bilateral hydronephrosis and 32 cases of unilateral hydronephrosis. The average time of UAS was detected (14.7±6.5)months after radical cystectomy. There were 32 patients of unilateral hydronephrosis and 2 patients of bilateral hydronephrosis. Two patients had undergone nephrostomy in an external hospital. Three patients had elevated leukocytes in blood routine. Among them, two patients had fever. First, nephrostomy on the hydronephrosis side and anti-infection treatment were performed. After routine blood tests showed that the white blood cells were normal and antibiotics were stopped for 24 hours without fever, the operation was performed. 34 patients had preoperative hydronephrosis of (2.7±0.6) cm. Of the 34 cases in this group, 5 cases were injected with methylene blue through a preoperative nephrostomy tube, and 29 were injected with methylene blue through the renal pelvis using an 18G puncture needle under ultrasound guidance. Using a ureteroscope to observe in the ileal bladder, methylene blue was seen in 4 cases. Methylene blue was used to guide the search for the stenosis and a super smooth guide wire was inserted. Among them, 3 cases were dilated with a 5 mm ureteral dilation balloon catheter, 1 case was dilated with a F14 ureteral access sheath, and then a F6 single J stent was inserted. Methylene blue was not seen in the ileal conduit in 30 cases, of which 16 cases were treated with a flexible ureteroscope through the nephrostomy to locate the stenosis, incised with a 30 W holmium laser. 9 cases were treated with 5 mm ureteral dilation balloon catheter, and 7 cases were treated with a F14 ureteral access sheath, and then an F6 single J stent was inserted. 14 cases were unable to find the stenosis by antegrade method. According to the operation time and patient's condition, it was decided to perform immediate or second stage dual endoscope surgery. Through the nephrostomy, a flexible ureteroscope was used to enter the stenosis along the super slide guide wire. A rigid ureteroscope was used to observe the stenosis through the ileal conduit, and the stenosis was found. The stenosis was found in 10 cases and incised with a 30 W holmium laser. 8 cases were treated with 5 mm ureteral dilation balloon catheter, and 2 cases were treated with a F14 ureteral access sheath, and then an F6 single J stent was inserted. 4 cases were still unable to accurately locate the stenosis using the dual endoscope surgery(one case was bilateral stenosis, and one side was relieved), and continued indwelling nephrostomy. The definition of successful removal of stricture in this study is that an F6 single J stent can be inserted into the ureter.Results:UAS were classified into four types based on the severity of the intraoperative findings: Type Ⅰ, the narrow ureteral lumen is more than 50% narrower than the normal ureteral lumen, but methylene blue can pass through in strands; Type Ⅱ, needle like stricture of the ureteral lumen, allowing only methylene blue filaments to pass through; Type Ⅲ, membranous atresia of the ureter, with a narrow segment of 1 to 3 mm in length, and methylene blue cannot pass through; Type Ⅳ, long segment stenosis. Of the 34 cases in this group, 4 cases were type Ⅰ, and the stenosis was dredged by retrograde method; 16 cases were type Ⅱ, and the stenotic segments were dredged by antegrade method; 10 cases were type Ⅲ, and the stenosis was dredged by the dual endoscope surgery; Four cases were of type Ⅳ (one case was of bilateral UAS, one side was of type Ⅲ, and the other side was of type Ⅳ, which was classified as type Ⅳ). The stenotic segment could not be solved through the above methods. Among the 34 patients, 30 patients were successfully relieved of anastomotic obstruction, and 1 patient with bilateral obstruction was unilaterally relieved of anastomotic obstruction. In the other 3 cases, because the stenosis segment was too long, 2 cases were changed to nephrostomy, and 1 case was changed to open surgery, with a success rate of 88.2%. UAS was classified into 4 types based on the severity of UAS seen during surgery. No serious complications occurred during and after the operation. During the follow-up of 6-24 months, the imaging evaluation of 4 patients showed that hydronephrosis was aggravated, with an average increase in creatinine of (32.5±10.9)μmol/L, requiring replacement of a single J tube. The imaging evaluation of the remaining 26 patients showed that the postoperative hydronephrosis was 0.9 ± 0.6 cm less than the preoperative hydronephrosis 2.6 ± 0.6 cm, with a statistically significant difference ( P<0.01). The quality of life score at 3 months after surgery was (1.9±0.6), which was significantly improved compared to the preoperative indwelling nephrostomy period (5.2±0.7), with a statistically significant difference ( P<0.01) Conclusions:The treatment of UAS after radical cystectomy with retrograde, antegrade, and dual endoscope surgery has a high success rate, which can help some patients avoid the inconvenience of indwelling external drainage tubes and the risk of open surgery. Choosing an appropriate surgical method can achieve the goal of treating UAS with minimal trauma.

Value of Reduced Field-of-view DWI in Quantitative Assessment of Axial Spondyloarthritis / 中山大学学报(医学科学版)

ObjectiveTo investigate the value of reduced field-of-view DWI （r-FOV DWI） in quantitative assessment of axial spondyloarthritis. MethodsA total of 112 patients with chronic back pain or suspected axial spondyloarthritis receiving full field-of-view DWI （f-FOV DWI） and reduced field-of-view DWI （r-FOV DWI） from December 2019 to December 2021 were enrolled. Next， subjective image quality assessment （anatomical detail， artifacts， distortion， overall image quality） and objective image quality assessment including （signal to noise ratio and contrast to noise ratio） were conducted by two experienced radiologists. In addition， the Apparent Diffusion Coefficient （ADC） values of three groups （active group， inactive group， and control group） on the two DWI sequences were measured by the two radiologists， respectively. Finally， the consistency of measurement between the two researchers was evaluated and the differences in ADC values was compared. Results102 patients were included and were divided into three groups， including the active group （n=32）， inactive group （n=29）， and control group （n=41） according to ASAS diagnostic criteria. All subjective and objective image quality metrics were rated in favor of r-FOV DWI images compared with f-FOV DWI images ［overall image quality： DWI 4（3~4） vs. 3（3~3） and SNR： 6.58（5.05~10.38） vs. 4.46（2.37~10.04）， CNR： 2.04（-1.14~8.29） vs. 0.97（-8.19~7.12）；P＜0.05］. Inter-rater consistency of the two researchers were 0.60~0.74. According to the AUC curve， group inactive vs. control showed r-FOV DWI was better than f-FOV DWI. In other groups （lesion vs. control， active vs. inactive）， there were no differences between both sequences（P＜0.05）. ConclusionThe subjective image quality score and signal to noise ratio of r-FOV DWI were higher than those of f-FOV DWI， which could be used for quantitative assessment of axial spondyloarthritis.

Discussion on discipline of herbalism / 中国中药杂志

Since the emergence of the term "materia medica", scholars have proposed different opinions on its concept. This term has been used to refer to traditional Chinese medicines, or medical books, or traditional pharmacology. Due to the differences in the concept of materia medica, scholars also have controversies about the concept of herbalism. Herbalism is usually understood as traditional Chinese pharmacology. After years of evolution, the term "herbalism" has now possessed the characteristics of an independent discipline, which can be defined as an applied basic discipline that comprehensively utilizes traditional and modern technological methods to study the formation, development, and changes of traditional pharmacology and reveal the basic theories and application laws of traditional medicine. At present, the research content of herbalism mainly includes three aspects: materia medica history, materia medica literature, and traditional pharmacology. This study explores the disciplinary concepts and main research content of herbalism based on a systematic review of the literature about the concepts of materia medica and herbalism, with the aim of attracting more attention to promote the establishment and development of the discipline of herbalism.

Genetically Encoded Light-Up RNA Amplifier Dissecting MicroRNA Activity in Live Cells.

Live cell dissection of microRNA activities is crucial for basic and translational medicine, but current hybridization-based strategies may fail to dissect surrounding-dependent activities. Here, we develop a genetically encoded miRNA-induced light-up RNA amplifier (iLAMP) that enables fast-activated, signal-amplified, fluorogenic imaging of miRNA activities in live cells. iLAMP responds to miRNA targets in the mode of "activation upon cleavage", in which the light-up RNA aptamer restores its fluorescence rapidly upon cleavage by the RNA-induced silencing complex. We demonstrate that iLAMP affords substantial signal amplification of ∼100-fold and high specificity in single nucleotide discrimination because of the miRNA-mediated cyclic cleavage. Combined with a Mango RNA aptamer reference module and a pseudoknot terminal stabilizer, iLAMP is shown for quantitative ratiometric imaging and dynamic monitoring of miRNA activities under exogenous stimulations. iLAMP is featured by a modular "plug and play" design and can be readily adapted to the detection of other miRNAs, highlighting its potential in tracking cell differentiation and screening miRNA therapeutics.

Small-Molecule-Mediated Split-Aptamer Assembly for Inducible CRISPR-dCas9 Transcription Activation.

Inducible CRISPR-dCas9 transcription system has become a powerful tool for transcription regulation and sensing. Here, we develop a new concept of small-molecule-mediated split-aptamer assembly for inducible CRISPR-dCas9 transcription activation, allowing quantitative detection and imaging of S-adenosyl methionine (SAM) in live cells. This inducible transcription system is designed by integrating one fragment of a split SAM aptamer to guide RNA (gRNA) and the other to MS2 arrays. SAM-mediated reassembly of the split fragments recruits an MCP-fused transcription activator to the gRNA-dCas9 complex, activating the expression of a near-infrared fluorescent protein for imaging. We demonstrate that this inducible transcription system achieves quantitative detection of SAM with high sensitivity in live cells. Our system shows that methionine adenosyltransferase 1A (MAT1A) and MAT2A can both catalyze SAM production in live cells and the SAM levels in cancer cells can be increased via upregulation of MAT1A mRNA by epigenetic inhibitors. This split-aptamer assembly strategy could afford a new approach for controlling the CRISPR-dCas9 system, enabling conditional transcription regulation in response to endogenous metabolites in live cells.

Interleukin 6 induces osteogenic differentiation and calcification of human umbilical artery smooth muscle cells via trans-signaling pathway / 中华风湿病学杂志

Objective:To explore the trans-membrane signaling mechanism of interleukin-6 (IL-6)-induced osteogenic differentiation and calcification of human umbilical artery smooth muscle cells (HUASMCs).Methods:HUASMCs were primarily cultured in vitro and were stimulated with IL-6, IL-6+solutable IL-6 receptor (sIL-6R), IL-6+sIL-6R+solutable gp130 (sgp130), or vehicle (blank control). Alizarin red and Von Kossa staining were used for detecting cell calcification, Western blot was used to test the protein expression of tissue-nonspecific alkaline phosphatase (TNAP), osteopontin (OPN), bone morphogenetic protein-2 (BMP-2) and Runt related transcription factor 2 (Runx2), and immunofluorescence was used to examine the mIL-6R expression of HUASMCs. The comparison of measurement date between the two groups was conducted by t-test. The comparison of measurement date between multiple groups was conducted by one-way analysis of variance (ANOVA). Results:The intensity severity of calcification stain was IL-6+sIL-6R group >IL-6+sIL-6R+sgp130 group>IL-6 group=blank control. After stimulated for 12 hours, the TNAP expression in blank control, IL-6 group, IL-6+sIL-6R group, IL-6+sIL-6R+sgp130 group were (0.44±0.08), (0.52±0.14), (0.84±0.16) and (0.55±0.10) respectively ( F=290.96, P<0.001). After stimulated for 3 days, the OPN expression in blank control, IL-6 group, IL-6+sIL-6R group, IL-6+sIL-6R+sgp130 group were (0.61±0.84), (0.95±0.16), (1.65±0.24) and (0.99±0.10) respectively ( F=507.72, P<0.001). After stimulated for 12 hours, the BMP-2 expression in blank control, IL-6 group, IL-6+sIL-6R group, IL-6+sIL-6R+sgp130 group were (0.77±0.05), (1.69±0.16), (2.81±0.26) and (0.57±0.12) respectively ( F=959.09, P<0.001). After stimulated for 3 days, the Runx2 expression in blank control, IL-6 group, IL-6+sIL-6R group,IL-6+sIL-6R+sgp130 group were (0.57±0.03) , (0.92±0.10), (1.31±0.13) and (0.66±0.06) respectively ( F=1141.27, P<0.001). Comparing with Jurkat cells (positive control) and CEM cells (negative control), HUASMCs limited expressed mIL-6R. Conclusion:IL-6 may induce HUASMCs osteogenic differentiation and calcification mainly via the sIL-6R-mediated trans-signaling pathway.

Initial Experience of Drug-Eluting Bead-Transcatheter Arterial Chemoembolization After Lipiodol-Based Transcatheter Arterial Chemoembolization Failure for Patients with Advanced Hepatocellular Carcinoma.

PURPOSE: To investigate the potential safety and efficacy of drug-eluting bead-transcatheter arterial chemoembolization (DEB-TACE) in treating TACE-refractory hepatocellular carcinoma (HCC). METHODS: We retrospectively evaluated the treatment outcomes of DEB-TACE for 41 HCC nodules in 30 patients who were refractory to conventional TACE (c-TACE) according to tumor response. The antitumor response was evaluated according to mRECIST criteria, and changes in alpha-fetoprotein (AFP), albumin-bilirubin score, the incidence of adverse events, and the time to disease progression were observed. RESULTS: The objective response rate and disease control rates were 60.98% and 95.12% at 4 weeks after DEB-TACE, 63.41% and 92.68% at 8 weeks, respectively. The median time of disease progression was 4.60 ± 0.23 months. The AFP of patients decreased continuously at 2-6 weeks after operation, and the AFP at 4 weeks was significantly lower than that at 2 weeks (P = 0.038). Adverse reactions were well tolerated, and no grade 4 adverse reactions were reported. The albumin-bilirubin score did not deteriorate within 6 weeks. CONCLUSION: DEB-TACE has potential efficacy and safety after failure of c-TACE in patients with advanced liver cancer. Further studies are needed to confirm the efficacy of DEB-TACE treatment after failure of c-TACE.

Design, synthesis, biological evaluation and molecular dynamics of LAR inhibitors.

In this study, firstly, the pharmacophore model was established based on LAR inhibitors. ZINC database and drug-like database were screened by Hypo-1-LAR model, and the embryonic compound ZINC71414996 was obtained. Based on this compound, we designed 9 compounds. Secondly, the synthetic route of the compound was determined by consulting Reaxys and Scifinder databases, and 9 compounds (1a-1i) were synthesized by nucleophilic substitution, Suzuki reaction and so on. Meanwhile, their structures were confirmed by 1H NMR and 13C NMR. Thirdly, the Enzymatic assays was carried out, the biological evaluation of compounds 1a-1i led to the identification of a novel PTP-LAR inhibitor 1c, which displayed an IC50 value of 4.8 µM. At last, molecular dynamics simulation showed that compounds could interact strongly with the key amino acids LYS1350, LYS1352, ARG1354, TYR1355, LYS1433, ASP1435, TRP1488, ASP1490, VAL1493, SER1523, ARG1528, ARG1561, GLN1570, LYS1681, thereby inhibiting the protein activity. This study constructed the pharmacophore model of LAR protein, designed small-molecule inhibitors, conducted compound synthesis and enzyme activity screening, so as to provide a basis for searching for drug-capable lead compounds.

Genetically Encoded Dual-Color Light-Up RNA Sensor Enabled Ratiometric Imaging of MicroRNA.

MicroRNAs (miRNAs) play essential roles in regulating gene expression and cell fate. However, it remains a great challenge to image miRNAs with high accuracy in living cells. Here, we report a novel genetically encoded dual-color light-up RNA sensor for ratiometric imaging of miRNAs using Mango as an internal reference and SRB2 as the sensor module. This genetically encoded sensor is designed by expressing a splittable fusion of the internal reference and sensor module under a single promoter. This design strategy allows synchronous expression of the two modules with negligible interference. Live cell imaging studies reveal that the genetically encoded ratiometric RNA sensor responds specifically to mir-224. Moreover, the sensor-to-Mango fluorescence ratios are linearly correlated with the concentrations of mir-224, confirming their capability of determining mir-224 concentrations in living cells. Our genetically encoded light-up RNA sensor also enables ratiometric imaging of mir-224 in different cell lines. This strategy could provide a versatile approach for ratiometric imaging of intracellular RNAs, affording powerful tools for interrogating RNA functions and abundance in living cells.

Comparative study on the parameters between reflux asthma and typical gastroesophageal reflux disease / 中华消化杂志

Objective:To analyze the difference and clinical significance of reflux related parameters between patients with reflux asthma (RA) and typical gastroesophageal reflux disease (TGERD).Methods:From June 2017 to June 2020, at PLA Rocket Force Characteristic Medical Center, the clinical data of 120 patients with gastroesophageal reflux disease (GERD) who underwent gastroscopy, high-resolution esophageal manometry (HREM) and 24 h pH-impedance monitoring contemporaneously were retrospectively analyzed. The GERD patients were divided into RA group and TGERD group according to the symptom correlated indexes, 60 cases in each group. The reflux related indexes of two groups were compared, which included reflux esophagitis (RE) score, esophageal hiatal hernia, Hill grade score of gastroesophageal flap valve, upper esophageal sphincter (UES) pressure, DeMeester score, and reflux episodes. Mann-Whitney U test and chi-square test were used for statistical analysis. Results:There were no significant differences in RE score and Hill grade score between TGERD group and RA group (0.0, 0.0 to 1.0 vs. 0.0, 0.0 to 1.8; 3.0, 2.0 to 3.0 vs. 3.0, 2.0 to 3.0) (both P>0.05). The detection rate of UES pressure less than 34 mmHg (1 mmHg=0.133 kPa) of RA group was higher than that of TGERD group (41.7%, 25/60 vs. 23.3%, 14/60), and the difference was statistically significant ( χ2=4.596, P=0.032). The UES pressure of RA group was lower than that of TGERD group (51.7 mmHg, 23.6 mmHg to 70.1 mmHg vs. 62.0 mmHg, 37.4 mmHg to 77.4 mmHg), and the difference was statistically significant ( Z=-2.105, P=0.035). There were no significant differences in other parameters of HREM between TGERD group and RA group (all P>0.05). The detection rates of DeMeester score more than 14.7, acid exposure time more than 4.5% and total reflux episodes more than 73 episodes of RA group were all higher than those of TGERD group (41.7%, 25/60 vs. 23.3%, 14/60; 40.0%, 24/60 vs. 21.7%, 13/60; 38.3%, 23/60 vs. 20.0%, 12/60, respectively), and the differences were all statistically significant ( χ2=5.546, 4.728 and 4.881, all P<0.05). The total reflux episodes and weak acid gas reflux episodes of RA group were both higher than those of TGERD group (60 episodes, 43 episodes to 98 episodes vs. 52 episodes, 34 episodes to 69 episodes; 12 episodes, 6 episodes to 21 episodes vs. 9 episodes, 3 episodes to 14 episodes), and the differences were statistically significant ( Z=-2.323 and -2.053, both P<0.05). There were no significant differences in other parameters of 24 h pH-impedance monitoring between TGERD group and RA group (all P>0.05). Conclusion:Low UES pressure, abnormal esophageal acid exposure and increased reflux episodes, especially weak acid gas reflux episodes, may be more likely to induce RA.

Sudden sensorineural hearing loss and ischemic stroke / 国际脑血管病杂志

Sudden sensorineural hearing loss (SSNHL) refers to the sudden and unexplained sensorineural hearing loss within 72 h and a decrease in hearing of ≥30 dB affecting at least 3 consecutive frequencies. It is one of the common emergencies in neurology and otolaryngology. Early etiological evaluation and systematic and targeted treatment are very important for delaying the progression of SSNHL and restoring hearing. Recent studies have shown that SSNHL overlaps with vascular risk factors of ischemic stroke, and may predict the risk of ischemic stroke. SSNHL may be one of the clinical manifestation and even the prodromal symptoms of ischemic stroke, especially the infarction of the blood supply area of the anterior inferior cerebellar artery or its branch internal auditory artery. Although these factors can not fully reveal the relationship between SSNHL and ischemic stroke, they are enough to warn clinicians that they should consider the possibility of ischemic stroke when receiving patients with SSNHL. Screening of vascular risk factors for patients with SSNHL as early as possible is helpful to avoid the risk of recurrence of ischemic stroke.

Cascade Circuits on Self-Assembled DNA Polymers for Targeted RNA Imaging In Vivo.

DNA molecular probes have emerged as a powerful tool for RNA imaging. Hurdles in cell-specific delivery and other issues such as insufficient stability, limited sensitivity, or slow reaction kinetics, however, hinder the further application of DNA molecular probes in vivo. Herein, we report an aptamer-tethered DNA polymer for cell-specific transportation and amplified imaging of RNA in vivo via a DNA cascade reaction. DNA polymers are constructed through an initiator-triggered hybridization chain reaction using two functional DNA monomers. The prepared DNA polymers show low cytotoxicity and good stability against nuclease degradation and enable cell-specific transportation of DNA circuits via aptamer-receptor binding. Moreover, assembling the reactants of hairpins C1 and C2 on the DNA polymers accelerates the response kinetics and improves the sensitivity of the cascade reaction. We also show that the DNA polymers enable efficient imaging of microRNA-21 in live cells and in vivo via intravenous injection. The DNA polymers provide a valuable platform for targeted and amplified RNA imaging in vivo, which holds great implications for early clinical diagnosis and therapy.

Gold Nanoflares with Computing Function as Smart Diagnostic Automata for Multi-miRNA Patterns in Living Cells.

Investigating the multimolecule patterns in living cells is of vital importance for clinical and biomedical studies. Herein, we reported for the first time the engineering of gold nanoflares as smart automata to implement computing-based diagnosis in living mammalian cells. Defining the logic combinations of miR122 and miR21 as the detection patterns, the corresponding OR and AND diagnostic automata were designed. The results showed that they could recognize the correct patterns rapidly and sensitively. The automata could enter cells via self-delivery and have good biocompatibility. They enabled accurate diagnosis on miRNA signatures in different cell lines and differentiation of fluctuations in the same cell line at single cell resolution. Moreover, the automata afforded an innovative diagnostic mode. It simplified the complicated process of detecting, data-collecting, computing, and evaluating. The direct diagnosing result ("1" or "0") was exported according to the embedded computation code. It highlighted the new possibility of using smart automata for intelligent diagnostics and cancer therapy at single cell resolution.

Activatable CRISPR Transcriptional Circuits Generate Functional RNA for mRNA Sensing and Silencing.

CRISPR-dCas9 systems that are precisely activated by cell-specific information facilitate the development of smart sensors or therapeutic strategies. We report the development of an activatable dCas9 transcriptional circuit that enables sensing and silencing of mRNA in living cells using hybridization-mediated structure switching for gRNA activation. The gRNA is designed with the spacer sequence blocked by a hairpin structure, and mRNA hybridization induces gRNA structure switching and activates the transcription of reporter RNA. An mRNA sensor developed using a light-up RNA reporter shows high sensitivity and fast-response imaging of survivin mRNA in cells under drug treatments and different cell lines. Furthermore, a feedback circuit is engineered by incorporating a small hairpin RNA in the reporter RNA, demonstrating a smart strategy for dynamic sensing and silencing of survivin with induced tumor cell apoptosis. This circuit illustrates a broadly applicable platform for the development of cell-specific sensing and therapeutic strategies.

Gentiopicroside Ameliorates the Progression from Hepatic Steatosis to Fibrosis Induced by Chronic Alcohol Intake

In current study, we aimed to investigate whether the gentiopicroside (GPS) derived from Gentiana manshurica Kitagawa could block the progression of alcoholic hepatic steatosis to fibrosis induced by chronic ethanol intake. C57BL/6 mice were fed an ethanol- containing Lieber-DeCarli diet for 4 weeks. LX-2 human hepatic stellate cells were treated with GPS 1 h prior to transforming growth factor-β (TGF-β) stimulation, and murine hepatocyte AML12 cells were pretreated by GPS 1 h prior to ethanol treatment. GPS inhibited the expression of type I collagen (collagen I), α-smooth muscle actin (α-SMA) and tissue inhibitor of metal protease 1 in ethanol-fed mouse livers with mild fibrosis. In addition, the imbalanced lipid metabolism induced by chronic ethanol-feeding was ameliorated by GPS pretreatment, characterized by the modulation of lipid accumulation. Consistently, GPS inhibited the expression of collagen I and α-SMA in LX-2 cells stimulated by TGF-β. Inhibition of lipid synthesis and promotion of oxidation by GPS were also confirmed in ethanol-treated AML12 cells. GPS could prevent hepatic steatosis advancing to the inception of a mild fibrosis caused by chronic alcohol exposure, suggesting GPS might be a promising therapy for targeting the early stage of alcoholic liver disease.

Nordihydroguaiaretic acid reverses efflux pump system MexCD-OprJ mediated ceftazidime resistance of pseudomonas aeruginosa and its related mechanisms / 中草药

Objective: To evaluate the effect of nordihydroguaiaretic acid (NDGA) on ceftazidime resistance of Pseudomonas aeruginosa mediated by efflux pump system MexCD-OprJ and explore its mechanism. Methods: The bacterial solution with a concentration of 0.5 mcburney was diluted and inoculated in a 96-well plate, and NDGA and ceftazidime were added by the checkerboard dilution method. At the same time, the untreated control group, NDGA control group and ceftazidime control group were set; After being cultured for 24 h, the absorbance was measured by an enzyme micro-plate reader, the minimum inhibitory concentration (MIC) of each drug was recorded and the bacteriostatic rate and fractional inhibitory concentration (FIC) index were calculated. Bacteria were inoculated with the bacterial liquid coating method in the 96-well plates, and the bacterial colony number was counted after 24 h of culture. Quantitative real-time polymerase chain reaction (qRT-PCR) was performed to detect the gene expressions of efflux pump membrane protein MexC, MexD, OprJ and nfxB. Results: Compared with ceftazidime or NDGA alone, combination of ceftazidime and NDGA significantly inhibited the growth of efflux pump system MexCD-OprJ-mediated ceftazidime-resistant P. aeruginosa (P < 0.05); The pharmacological effects of ceftazidime and NDGA showed synergistic or additive effects; After combined administration, the MIC values of ceftazidime and NDGA were significantly decreased, and the MIC value of some ceftazidime had no significant difference from that of ceftazidime-sensitive P. aeruginosa; Compared with ceftazidime alone, the gene expressions of efflux pump membrane proteins MexC, MexD and OprJ were significantly decreased after combined application of ceftazidime and NDGA (P < 0.05), while the expression of nfxB was significantly increased (P < 0.05). Conclusion: The mechanism of NDGA on ceftazidime resistance of P. aeruginosa mediated by efflux pump system MexCD-OprJ is related to its ability to down-regulate the gene expression of efflux pump membrane proteins MexC, MexD and OprJ, and up-regulate the gene expression of the negative regulatory gene nfxB of the above three proteins.

Exploring the effect of aplidin on low molecular weight protein tyrosine phosphatase by molecular docking and molecular dynamic simulation study.

The low molecular weight protein tyrosine phosphatase (LMW-PTP) could regulate many signaling pathways, and it had drawn attention as a potential target for cancer. As previous report has indicated that the aplidin could inhibit the LMW-PTP, and thus, the relevant cancer caused by the abnormal regulation of the LMW-PTP could be remission. However, the molecular mechanism of inhibition of the LMW-PTP by the aplidin had not been fully understood. In this study, various computational approaches, namely molecular docking, MDs and post-dynamic analyses were utilized to explore the effect of the aplidin on the LMW-PTP. The results suggested that the intramolecular interactions of the residues in the two sides of the active site (Ser43-Ala55 and Pro121-Asn134) and the P-loop region (Leu13-Ser19) in the LMW-PTP was disturbed owing to the aplidin, meanwhile, the π-π interaction between Tyr131 and Tyr132 might be broken. The Asn15 might be the key residue to break the residues interactions. In a word, this study may provide more information for understanding the effect of inhibition of the aplidin on the LMW-PTP.

A single promoter system co-expressing RNA sensor with fluorescent proteins for quantitative mRNA imaging in living tumor cells.

Genetically encoded light-up RNA aptamers afford a valuable platform for developing RNA sensors toward live cell imaging. However, quantitative imaging of intracellular RNAs remains a grand challenge. Here we reported a novel genetically encoded RNA sensor strategy using a plasmid that expresses a splittable fusion of the RNA sensor and the GFP mRNA in an individual transcript using a single promoter system. This splittable fusion design enables synchronous co-expression of the RNA sensor with GFP mRNA while alleviates the interference with correct folding of RNA aptamers due to intramolecular hybridization. This single-promoter system is applied to ratiometric imaging of survivin mRNA in tumor cells. The results reveal that the ratiometric images dynamically correlated with survivin mRNA concentrations and allow quantitative imaging of survivin mRNA in different tumor cells. The RNA sensor strategy may provide a new paradigm for developing a robust imaging platform for quantitative mRNA studies in living cells.