人参皂苷Rh2对免疫低下小鼠的免疫调节作用

目的研究人参皂苷Rh2的免疫调控功能。方法 6周龄C57BL/6J雄性小鼠采用X射线一次性全身照射建立放疗模型,腹腔注射甲氨蝶呤建立免疫低下模型。两种模型均分为空白对照组(n=10)、模型对照组(n=15)、胸腺五肽组(n=15)、人参皂苷Rh2组(n=15)。空白对照组和模型对照组按每只0.2 mL灌胃0.9%氯化钠溶液,胸腺五肽组按0.1 mg·kg^(-1)腹腔注射胸腺五肽,人参皂苷Rh2组按10 mg·kg^(-1)灌胃,每天1次。放疗模型于第3,5,7天取材,甲氨蝶呤致免疫低下模型第15天取材。采用流式细胞术检测脾脏和胸腺中免疫细胞的百分率,酶联免疫吸附测定(ELISA)检测血清中细胞因子的含量。结果人参皂苷Rh2可缓解小鼠放疗和甲氨蝶呤导致的体质量下降。与模型对照组比较,Rh2能增加脾脏、胸腺淋巴细胞中CD_4^+T细胞和CD_8^+T细胞的数量(P<0.05或P<0.01),增加脾脏中自然杀伤细胞(NK)的数量,提高T细胞受体(TCR)的表达(P<0.05或P<0.01),减少脾脏中髓来源的抑制性细胞(MDSC)的数量(P<0.05或P<0.01),提高树突状细胞(DCs)表面共刺激分子MHCII的表达(P<0.05),降低DCs表面负性调控分子:程序性死亡分子1配体(PD-L1)的表达(P<0.05),促进血清中Th1型细胞因子白细胞介素2(IL-2)和肿瘤坏死因子α(TNF-α)的分泌(P<0.05或P<0.01)。结论人参皂苷Rh2能缓解小鼠放疗以及免疫抑制剂所致的免疫低下状态,该作用与促进天然免疫细胞分化成熟以及免疫效应细胞的增殖,提高Th1型细胞因子的分泌水平,增强免疫功能有关。

A soy glycinin derived octapeptide protects against MCD diet induced non-alcoholic fatty liver disease in mice

Soy glycinin derived octapeptide(SGP8)is a peptide obtained from degradation of the soy glycinin,whose amino acid sequence is IAVPGEVA.To determine the effect of SGP8 on non-alcoholic fatty liver disease(NAFLD),steatosis Hep G2 cells were induced by 1 mmol/L free fatty acid(FFA)and C57 BL/6 J mice were fed with methionine-choline defi cient(MCD)diet for 3 weeks to establish NAFLD model.The results of oil red O staining and total cholesterol(TC)/triglyceride(TG)contents showed that SGP8 could signifi cantly reduce the lipid content of steatosis Hep G2 cells.In vivo,SGP8 lowered plasma alanine aminotransferase(ALT)and low density lipoprotein(LDL)content,normalized hepatic superoxide dismutase(SOD)and malondialdehyde(MDA)production,and reduced the severity of liver infl ammation.The results of Western blotting showed that SGP8 increased expression of Sirtuin-1(SIRT1)and phosphorylation level of AMP activated protein kinase(AMPK)in hepatocytes.Through activation of SIRT1/AMPK pathway,SGP8 downregulated the expression of sterol regulatory element binding protein 1 c(SREBP-1 c)and its target genes ACC and FAS expression levels,and increased the phosphorylation level of acetyl Co A carboxylase(ACC).Furthermore,SGP8 also upregulated the expression of transcription factor peroxisome proliferator activated receptorα(PPARα),which was regulated by SIRT1/AMPK pathway,and its target gene CPT1 level.In conclusion,SGP8 might improve NAFLD by activating the SIRT1/AMPK pathway.Our data suggest that SGP8 may act as a novel and potent therapeutic agent against NAFLD.

Investigation and Analysis of the Cognition of Menopause in Women Over 40 Years Old

Objective:To investigate and analyze the cognition of menopause in women over 40 years old.Methods:Using the stratified sampling method,224 females,age ranging from 40 to 60,from our university staff(Xi’an Medical University)and the surrounding communities were selected,and both online and offline questionnaires were distributed.Results:(1)224 questionnaires were recovered,with 204 valid questionnaires,among which 100 questionnaires were from our university staff(aged 42-60 years old)and 104 questionnaires from the surrounding communities(aged 40-60 years old);(2)the cognition of menopause among the surveyed population was found to be related to occupation and education level;the cognition of menopause among university staff(76%)was significantly higher than that of the surrounding communities(45.19%);(3)most people were able to accept menopausal hormone therapy;the degree of acceptance among the university staff(80%)was found to be higher than that among the surrounding communities(60.58%).Conclusion:According to the recovered data,women over the age of 40 have less than ideal cognition of menopause,and although the cognitive level of the university staff on menopause was found to be significantly higher than that of the surrounding communities,their cognitive level still requires improvement.

Conformational Folding Activates Photoinduced Electron Transfer

Photoinduced electron transfer(PET)is a critical process in many functional materials,underpinning various technological applications(i.e.,fluorescent probes and photocatalysts).Despite its signifi-cance,the detailed structural dynamics of PET,particularly during the excited state,remain poorly understood.This study investigates the mechanisms of conformational folding and their implications for activating PET in molecular systems characterized by a fluorophore-spacer-receptor configuration.We demonstrate that traditional computational models,primarily based on frontier molecular orbitals,often fall short in capturing these conformational dynamics,leading to inadequate explanations of PET phenomena.With the incorporation of conformational folding,our computational model has achieved excellent agreement with experimental data,thereby resolving several long-standing debates on PET mechanisms.This mechanistic advancement not only deepens our understanding of PET but also opens new avenues for designing advanced functional materials.We have thus successfully demonstrated the imaging of lysosomes in live cells using a PET probe.

Recent advancements in DNA nanotechnology-enabled extracellular vesicles detection and diagnosis:A mini review

Extracellular vesicles(EVs)are cell-derived nanosized vesicles widely recognized for their critical roles in various pathophysiological processes.Molecular analysis of EVs is currently being considered an emerging tool for diseases diagnosis.However,the small size and heterogeneity of EVs has staggered the EVs research for diseases diagnosis.DNA nanotechnology enables self-assembly of versatile DNA nanostructures and has shown enormous potential in assisting EVs biosensing.In this review,we briefly introduce the recent advances in DNA nanotechnology approaches for EVs detection.The approaches were categorized based on the dimension of DNA nanostructures.We provide critical evaluation of these approaches,and summarize the pros and cons of specific methods.Further,we discuss the challenges and future perspectives in this field.

A fluorescent film sensor for high-performance detection of Listeria monocytogenes via vapor sampling

Foodborne Listeria monocytogenes poses serious threats to public health.Fast and sensitive detection of the pathogen at the point of contamination is thus crucial to halt the spread of bacteria-related diseases.Herein,we report for the first time a fluorescent film sensor to detect the biomarker of L.monocytogenes,3-hydroxy-2-butanone.The sensor demonstrated unprecedented sensing performance for the analyte with a detection limit lower than 0.05 mg/m^(3),response time less than 1 s,full reversibility,and excellent selectivity.Further study showed that the sensor can be used to monitor the growth of L.monocytogenes with much-improved sensitivity.The superior performance of the sensor is ascribed to the specific binding,efficient charge transfer emission,and porous adlayer structure of the specially designed sensing fluorophore-based film.Our work paves the way to develop a portable detector to meet the needs for on-site and real-time detection of foodborne pathogens.

Applications of aptamers for chemistry analysis, medicine and food security

Since aptamer and its in vitro selection process called SELEX were independently described by Ellington and Gold in 1990, extensive research has been undertaken and numerous isolated aptamers for various targets have been applied. Aptamers can bind to a wide range of targets that include small organic molecules, inorganic compounds, haptens and even whole cells with high binding affinity and specificity. Aptamers for a wide range of targets have been selected currently. In addition, aptamers are thermo stable and can also be regenerated easily within a few minutes denaturation, which makes them easy to store or handle. These advantages make aptamers extremely suitable for applications based on molecular recognition as analytical, diagnostic and therapeutic tools. In this review, the recent applications of aptamers for chemistry analysis, medicine and food security, along with the future trend will be discussed.

Current signal amplification strategies in aptamer-based electrochemical biosensor:A review

Due to their high specificity and affinity towards various targets,along with other unique advantages such as stability and low cost,aptamers are widely applied in analytical techniques.A typical aptamerbased electrochemical biosensor is composed of a aptamer as the biological recognition element and transducer converting the biologic interaction into electrical signals for the quantitative measurement of targets.Improvement of the sensitivity of a biosensor is significantly important in order to achieve the detection of biomolecules with low abundance,and different amplification strategies have been explored.The strategies either employ nanomaterials such as gold nanoparticles to con struct electrodes which can transfer the biological reactions more efficiently,or attempt to obtain enhanced signal through multi-labeled carriers or utilize enzyme mimics to catalyze redox cycling.This review discusses recent advances in signal amplification methods and their applications.Critical assessment of each method is also considered.

Hyaluronic acid-based dual-responsive nanomicelles mediated mutually synergistic photothermal and molecular targeting therapies

Precise clinical treatment of triple-negative breast cancer(TNBC)is an obstacle in clinic.Nanotechnology-assisted photothermal therapy(PTT)is a superior treatment modality for TNBC in terms of precision.However,thermoresistance arising from PTT and insufficient drug release from nanocarriers decrease the efficacy of PTT.AT13387 is a novel HSP90 inhibitor that can weaken thermoresistance and undergoing clinic II phase study,showing satisfactory antitumour activity through molecularly targeted therapy(MTT).Whereas,it has poor solubility.Hence hyaluronic acid and stearic acid were connected by hydrazone bonds and disulfide bonds,forming an amphipathic copolymer that could self-assembled into nanomicelles,followed by encapsulating Cypate and AT13387.These nanomicelles exhibited great features,including achieving mutually synergistic PTT/MTT for overcoming thermoresistance and promoting translocation of drugs,increasing the solubility of Cypate and AT13387,showing a pH/redox dual response that contributes to drug release,and having the ability of active targeting.Thus,the nanomicelles developed in this study may be a promising strategy for the precise treatment of TNBC.

Extracellular vesicles based electrochemical biosensors for detection of cancer cells:A review

Extracellular vesicles(EVs)derived from cancer cells are considered as ideal biomarker for liquid biopsy in cancer diagnosis,and are stable and abundant.Electrochemical methods for the detection of EVs are prefe rred over co nventional methods such as Western blotting and enzyme-linked immunosorbent assay for their high sensitivity and real-time detection.This article summaries studies proposing the electrochemical methods utilizing immunological and molecular methodologies for detecting EVs derived biomacromolecules such as miRNAs and transme mbrane protein for cancer diagnosis.Moreover,the electrochemical detection methods are compared and future prospects for the development of electrochemical methods for EVs detection are concluded.

The aptamers generated from HepG2 cells

Liver cancer, as the second cause of cancer death all around the world, resulted in a series of chronic liver diseases. More than 80%of the patients cannot receive effective treatment because of their advanced disease or poor liver function. It is time to improve early clinical diagnosis and find optimal therapeutic treatments. As the tumor cells behave differently from the cell-surface molecules, it is necessary to find a highly specific probe. The aptamers, known as "chemical antibodies", can bind to their target molecules with high affinity and high specificity. The apatmers were obtained by Cell-SELEX, which was aimed at finding the aptamers against whole living cells. In the article, after 19 selections, the ssDNA pool was cloned and sequenced. After that, six aptamers were obtained, named apt_A to apt_F. By incubating the aptamers with different cells, except apt_E, the other aptamers showed high specificity. As for apt_E, which showed high affinity to several cancer cells, was a potential probe for the common protein presented by several different cancer cells. The equilibrium dissociation constants(Kd) were evaluated by measuring the flow cytometry signal that characterized the binding ability of aptamers to the target cells at a series of concentrations ranging from 46.3(4.5) nM to 199.4(44.2) nM, which exposed the high binding affinities of these aptamers. The research in the confocal fluorescence images further confirmed the specificity of these aptamers and the fact that the aptamers were combined with the targets on the cell-surface.

New Fluorescent Conjugates Displaying Solvatochromic Properties

Four new fluorescent dyes based on bis（phenyl-ethynyl-）-2-naphthyl （BPEN） were designed and synthesized.To improve the solvatochromic property and enhance the brightness of the fluorescent BPEN,an electron-donating unit of azetidine and/or an electron deficient group of-NO2 was introduced.