BACKGROUND:Osteoporotic fracture is the most serious complication of osteoporosis.Previous studies have demonstrated that gut microbiota has a regulatory effect on skeletal tissue and that gut microbiota has an important relationship with osteoporotic fracture,but the causal relationship between the two is unclear. OBJECTIVE:To explore the causal relationship between gut microbiota and osteoporotic fractures using Mendelian randomization method. METHODS:The genome-wide association study(GWAS)datasets of gut microbiota and osteoporotic fracture were obtained from the IEU Open GWAS database and the Finnish database R9,respectively.Using gut microbiota as the exposure factor and osteoporotic fracture as the outcome variable,Mendelian randomization analyses with random-effects inverse variance weighted,MR-Egger regression,weighted median,simple model,and weighted model methods were performed to assess whether there is a causal relationship between gut microbiota and osteoporotic fracture.Sensitivity analyses were performed to test the reliability and robustness of the results.Reverse Mendelian randomization analyses were performed to further validate the causal relationship identified in the forward Mendelian randomization analyses. RESULTS AND CONCLUSION:The results of this Mendelian randomization analysis indicated a causal relationship between gut microbiota and osteoporotic fracture.Elevated abundance of Actinomycetales[odds ratio(OR)=1.562,95%confidence interval(CI):1.027-2.375,P=0.037),Actinomycetaceae(OR=1.561,95%CI:1.027-2.374,P=0.037),Actinomyces(OR=1.544,95%CI:1.130-2.110,P=0.006),Butyricicoccus(OR=1.781,95%CI:1.194-2.657,P=0.005),Coprococcus 2(OR=1.550,95%CI:1.068-2.251,P=0.021),Family ⅩⅢ UCG-001(OR=1.473,95%CI:1.001-2.168,P=0.049),Methanobrevibacter(OR=1.274,95%CI:1.001-1.621,P=0.049),and Roseburia(OR=1.429,95%CI:1.015-2.013,P=0.041)would increase the risk of osteoporotic fractures in patients.Elevated abundance of Bacteroidia(OR=0.660,95%CI:0.455-0.959,P=0.029),Bacteroidales(OR=0.660,95%CI:0.455-0.959,P=0.029),Christensenellacea(OR=0.725,95%CI:0.529-0.995,P=0.047),Ruminococcaceae(OR=0.643,95%CI:0.443-0.933,P=0.020),Enterorhabdus(OR=0.558,95%CI:0.395-0.788,P=0.001),Eubacterium rectale group(OR=0.631,95%CI:0.435-0.916,P=0.016),Lachnospiraceae UCG008(OR=0.738,95%CI:0.546-0.998,P=0.048),and Ruminiclostridium 9(OR=0.492,95%CI:0.324-0.746,P=0.001)would reduce the risk of osteoporotic fractures in patients.We identified 16 gut microbiota associated with osteoporotic fracture by the Mendelian randomization method.That is,using gut microbiota as the exposure factor and osteoporotic fracture as the outcome variable,eight gut microbiota showed positive causal associations with osteoporotic fracture and another eight gut microbiota showed negative causal associations with osteoporotic fracture.The results of this study not only identify new biomarkers for the early prediction of osteoporotic fracture and potential therapeutic targets in clinical practice,but also provide an experimental basis and theoretical basis for the study of improving the occurrence and prognosis of osteoporotic fracture through gut microbiota in bone tissue engineering.

Pyran- and furanocoumarins are key representatives of tetrahydropyrans and tetrahydrofurans, respectively, exhibiting diverse physiological and medical bioactivities. However, the biosynthetic mechanisms for their core structures remain poorly understood. Here we combined multiomics analyses of biosynthetic enzymes in Peucedanum praeruptorum and in vitro functional verification and identified two types of key enzymes critical for pyran and furan ring biosynthesis in plants. These included three distinct P. praeruptorum prenyltransferases (PpPT1-3) responsible for the prenylation of the simple coumarin skeleton 7 into linear or angular precursors, and two novel CYP450 cyclases (PpDC and PpOC) crucial for the cyclization of the linear/angular precursors into either tetrahydropyran or tetrahydrofuran scaffolds. Biochemical analyses of cyclases indicated that acid/base-assisted epoxide ring opening contributed to the enzyme-catalyzed tetrahydropyran and tetrahydrofuran ring refactoring. The possible acid/base-assisted catalytic mechanisms of the identified cyclases were theoretically investigated and assessed using site-specific mutagenesis. We identified two possible acidic amino acids Glu303 in PpDC and Asp301 in PpOC as vital in the catalytic process. This study provides new enzymatic tools in the epoxide formation/epoxide-opening mediated cascade reaction and exemplifies how plants become chemically diverse in terms of enzyme function and catalytic process.

ObjectiveTo study the characteristics of imprinting template of flavonoid clusters in four Chinese medicines attributed to the lung meridian， and to establish an in vitro experimental approach for the study of the attribution of Chinese medicines to the lung meridian. MethodBased on 13 Chinese medicines， including Xanthii Fructus， Houttuyniae Herba， Fagopyri Dibotryis Rhizoma， Belamcandae Rhizoma and so on， which only belong to the lung meridian in Chinese Materia Medica（the 13^th Five-Year planning textbook of general higher education）， we identified four representative Chinese medicines， namely Houttuyniae Herba， Fagopyri Dibotryis Rhizoma， Belamcandae Rhizoma and Mori Cortex， and set up their fingerprints by high performance liquid chromatography（HPLC） and calculated the molecular connectivity indices of various components in the four Chinese medicines， the similarity to their mean value was calculated by included angle cosine method， so as to establish the quantitative relationship of construction versus imprinting ability， and to determine the order of each component in the lung meridian. A total of 7 reference substances， including chlorogenic acid， rutin， quercetin， isoquercitrin， hyperoside， epicatechin， and iridin， were selected to validate the overall conformational relationships of flavonoids of the model， as well as its predictive ability. ResultHouttuyniae Herba， Fagopyri Dibotryis Rhizoma， Belamcandae Rhizoma and Mori Cortex contained a total of 437 chemical components with an average molecular connectivity index similarity of 0.995 6. The four Chinese medicines contained a total of 204 flavonoids with an average molecular connectivity index similarity of 0.978 0， which was second only to the alkaloids with 0.985 1. The retention time（t_R） of the 7 reference substances showed a good conformational relationship with the similarity of the molecular connectivity index（t_R=831.4×S-790.3， r=0.861 4， P<0.01）， which was applicable to the in vitro attribution study of the position， similarity， and relative similarity with t_R of the cluster of 98.04% of flavonoids. Accordingly， the 1^st position was kuwanon D， with a similarity of molecular connectivity index of 0.987 7 and a t_R of 30.88 min， the 200^th position was chlorogenic acid， with a similarity of molecular connectivity index of 0.958 2 and a t_R of 6.36 min. The total first-order moment of the four Chinese medicines calculated by total statistical moment method of fingerprint was 24.26 min， ranked 21， which could characterize 99.19% of the whole， and the total first-order moment of the total peak area of the 7 reference substances in the four Chinese medicines was 20.00 min， with a rank of 46， which could characterize 98.68% of the whole. ConclusionFlavonoid clusters are suitable probes for the characterization of imprinting template for the study of the lung meridian， which can be established a quantitative imprinting method for meridian tropism of Chinese medicines in vitro.

Parkinson's disease (PD) is a chronic neurodegenerative disease. At present, levodopa and other drugs are mainly used for dopamine supplementation therapy. However, the absorption of levodopa in the gastrointestinal tract is unstable and its half-life is short, and long-term use of levodopa will lead to the end-of-dose deterioration, dyskinesia, the "ON-OFF" phenomenon and other symptoms. Therefore, new preparations need to be developed to improve drug efficacy, reduce side effects or improve compliance of patients. Based on the above clinical needs, this review briefly introduced the preparation modification strategies for the treatment of PD through case analysis, in order to provide references for the research and development of related preparations.

A new method for simultaneous determination of 23 kinds of per-and polyfluoroalkyl substances(PFASs)(13 kinds of perfluoro carboxylic acids,4 kinds of perfluoro sulfonic acids,and 6 kinds of new substitutes)in plant leaf tissue by ultra-high performance liquid chromatography-tandem mass spectrometry(UHPLC-MS/MS)using automatic online solid phase extraction(SPE)to remove the matrix interference components in plant crude extracts was developed.The plant leaf samples were extracted twice with 1%formic acid-methanol solution,then evaporated to dry,redissolved with 70%methanol solution,and directly injected for analysis.After 23 kinds of target PFASs were purified automatically by online SPE with a WAX column,the six-way valve was switched to rinse PFASs onto an alkaline mobile phase system-compatible C18 analytical column.Then,the 23 kinds of target PFASs were separated within 16 min by gradient elution using a binary mobile phase system of methanol/water(Containing 0.4%ammonium hydroxide).Tandem mass spectrometry was performed in multiple reaction monitoring(MRM)mode for online detection of various PFASs,and quantification was carried out by internal standard method.The results of the method validation showed that satisfactory average recoveries of 23 kinds of PFASs in plant leaf samples(64.2%-125.5%),precision(relative standard deviations(RSDs)of 0.7%-12.8%),linearity(R2＞0.990),and sensitivity(the detection limits(S/N=3)were in the range of 0.02-0.50 μg/kg)were achieved.Finally,this method was used to detect PFASs in the marine green tide algae(Enteromorpha prolifera)and several tree leaves,and a total of 6 kinds of PFASs were detected,in which PFBA was the main contaminant.Compared with the reported offline SPE methods,the proposed online SPE technique significantly simplified the sample pretreatment process and provided an automatic,simple,and environment-friendly method for the routine monitoring of legacy and emerging PFASs in plant tissues.

Objective To investigate the role of complement C3 in early predicting pregnancy outcomes of frozen-thawed embryo transfer(F-ET).Methods A total of 378 F-ET cycles were prospectively collected and divided into group A(complement C3≤1.05,120 cycles)and group B(complement C3>1.05,258 cycles)based on the best cutoff value of complement C3 for predicting F-ET pregnancy outcomes.The outcomes of the two groups were compared,and the best cutoff value of complement C3 for predicting F-ET spontaneous abortion was analyzed in group B.Results Age was a risk factor for successful F-ET pregnancy(P<0.05),and complement C3 and embryo type were protective factors for successful F-ET pregnancy(P<0.05).The area under the receiver-operating characteristic curve(ROC)of complement C3 for predicting F-ET pregnancy outcome was 0.702,and the best cutoff value was 1.05 g/L,with a clinical pregnancy sensitivity of 87.60%and a specificity of 52.00%.The clinical pregnancy rate and embryo implantation rate in group B were both significantly higher than those in group A(67.05%vs.52.75%,P<0.05).The best cutoff value of complement C3 for predicting spontaneous abortion after F-ET was 1.32 g/L,with an area under the ROC curve of 0.760,a sensitivity of 69.00%,and a specificity of 81.20%.Conclusions Complement C3 is of significance in the early prediction of F-ET pregnancy outcome.When complement C3 exceeds the level of 1.32 g/L,it may lead to an increase in the rate of spontaneous abortion.

OBJECTIVE:To evaluate the efficacy of exosomes derived from mesenchymal stem cells on animal models of acute liver failure. METHODS:PubMed,Web of Science,Embase,The Cochrane Library,CBM,CNKI,WanFang,and VIP databases were retrieved from inception to January 16,2023.A series of animal experiments on the treatment of acute liver failure animal models by exosomes derived from mesenchymal stem cells were collected.Two evaluators screened the literature and extracted the data independently.The bias risk was evaluated by the SYRCLE tool.The extracted data were analyzed by Revmen 5.4.1 software and Stata 17.0 software. RESULTS:A total of 241 articles were retrieved and 9 animal experiments were included,with 219 animals:110 animals in the model group and 109 animals in the exosome group.The results showed that the survival rate of animals in the exosome group improved significantly[RR=9.34,95%CI(3.91,22.29),P<0.001],the levels of serum alanine transaminase[SMD=-5.31,95%CI(-7.43,-3.19),P<0.001]and aspartate aminotransferase[SMD=-4.47,95%CI(-5.85,-3.10),P<0.001]were reduced obviously.The expressions of interleukin-1β[SMD=-11.54,95%CI(-18.12,-4.95),P=0.000 6],interleukin-6[SMD=-5.75,95%CI(-8.08,-3.41),P<0.001]and tumor necrosis factor-α[SMD=-4.46,95%CI(-6.83,-2.09),P=0.000 2],were suppressed obviously. CONCLUSION:Exosomes derived from mesenchymal stem cells effectively inhibit the inflammatory response,ameliorate liver function of animals with acute liver failure,and improve their survival rate.The results of subgroup analysis showed that the shorter survival time of animals(≤24 hours),the lower dose of transplanted exosomes(<1 mg/kg)and the source of exosomes(adipose-derived mesenchymal stem cells)may affect the efficacy of the exosomes derived from mesenchymal stem cells in the animal model of acute liver failure.This conclusion and its clinical transformation still need to be confirmed by randomized controlled studies with large sample sizes and high quality.

BACKGROUND:Conductive biomaterials are considered potential candidates for transmitting electrical signals for myocardial repair.Combining cell-based or cell-free strategies with conductive biomaterials to replenish cardiomyocytes and/or restore electrical signaling pathways is a promising approach for cardiac repair. OBJECTIVE:To evaluate the effect of polypyrrole-chitosan conductive composite hydrogel on cardiac function in rats with myocardial ischemia-reperfusion injury. METHODS:The polypyrrole-chitosan conductive composite hydrogel was prepared by chemical oxidative polymerization.The micromorphology,biocompatibility and conductivity of the hydrogels were characterized.Thirty adult SD rats were selected to establish a myocardial ischemia-reperfusion injury model by clamping the left anterior descending branch of the heart and then releasing it.After 21 days of modeling,the rats were divided into three groups by the random number table method:Normal saline was injected into the left ventricular infarction area and infarction margin area in the blank group.Chitosan hydrogel was injected into the left ventricular infarction area and infarction margin area in the ordinary hydrogel group.The polypyrrole-chitosan conductive composite hydrogel was injected into the left ventricular infarction area and infarction margin area,with 10 rats in each group.The corresponding time points after modeling were set,and cardiac mechanical function(echocardiogram,pressure-volume analysis),cardiac electrophysiology(electrocardiogram,programmed electrical stimulation,optical mapping technology,microelectrode array technology,eight-lead electrocardiogram,and electrical resistivity of the scar area)and cardiac histology were detected. RESULTS AND CONCLUSION:(1)There were a lot of pores on the surface of the conductive composite hydrogel,and the conductivity was(3.19±0.03)×10-3 mS/cm,which had good biocompatibility co-cultured with smooth muscle cells.(2)After 105 days of modeling,echocardiogram and pressure-volume analysis showed that compared with the blank group and the ordinary hydrogel group,the conductive composite hydrogel could significantly improve the contractile function of the heart of rats with myocardial ischemia-reperfusion injury.The results of electrocardiogram,programmed electrical stimulation,optical mapping technology,microelectrode array technology,eight-lead electrocardiogram,and electrical resistivity of the scar area examination at 105 days after modeling displayed that,compared with the blank group and the ordinary hydrogel group,the conductive composite hydrogel could significantly improve the electrical conduction function of the heart of rats with myocardial ischemia-reperfusion injury and reduce the occurrence of arrhythmia.Masson staining of heart tissue at 105 days after modeling exhibited that there were different degrees of fibrosis in the myocardial infarction area of the three groups.Compared with the normal saline group and the ordinary hydrogel group,the conductive hydrogel group had more normal myocardial tissue and less fibrosis in the myocardial infarction area.(3)The results verify that polypyrrole-chitosan conductive composite hydrogel may promote the repair of infarcted heart after ischemia-reperfusion injury by increasing the electrical conduction velocity of infarct scar area tissue,increasing scar thickness,enhancing synchronous cardiac contraction,and reducing damaged tissue.

To establish and optimize a method for the detection of recombinant human midkine (rhMK) activity and verify its methodology, cell counting kit-8 (cck-8) method was used to measure the proliferation activity of rat knee chondrocytes. The specificity, accuracy, precision, linearity and robustness of the method were also verified in this study. The established method was proven to have good specificity because the buffer of rhMK and recombinant human interleukin-1 receptor antagonist have no obvious active effect; the recoveries of the samples with relative activities of 50%, 75%, 100%, 125%, 150% were in the range of 80.0% to 124.0% by statistical analysis, the relative standard deviations (RSD) of relative potency were all within 20%, the linear correlation coefficient, R² ≥ 0.98, suggesting that the accuracy, precision and linearity of the method were good; the robustness correlation coefficient, R² ≥ 0.92 and the ratio of maximum to minimum of sigmoidal dose-response were no less than 1.5, indicating that robustness of the methods was good. In conclusion, a bioactivity measurement method for rhMK was established and fully validated in this study and it provides a reliable method for the bioactivity analysis of rhMK routine samples during the development. This study was approved by the Animal Care and Use Committee of Shanghai Model Organisms Center, Inc. (approval number: 2019-0008-06).

Platycodonis Radix is the dry root of Platycodon grandiflorum of Campanulaceae, which has a variety of pharmacological effects and is a commonly used bulk Chinese medicine. In this study, the chloroplast genome sequences of six P. grandiflorum from different producing areas has been sequenced with Illumina HiSeq X Ten platform. The specific DNA barcodes were screened, and the germplasm resources and genetic diversity were analyzed according to the specific barcodes. The total length of the chloroplast genome of 6 P. grandiflorum samples was 172 260-172 275 bp, and all chloroplast genomes showed a typical circular tetrad structure and encoded 141 genes. The comparative genomics analysis and results of amplification efficiency demonstrated that trnG-UCC and ndhG_ndhF were the potential specific DNA barcodes for identification the germplasm resources of P. grandiflorum. A total of 305 P. grandiflorum samples were collected from 15 production areas in 9 provinces, for which the fragments of trnG-UCC and ndhG_ndhF were amplificated and the sequences were analyzed. The results showed that trnG-UCC and ndhG_ndhF have 5 and 11 mutation sites, respectively, and 5 and 7 haplotypes were identified, respectively. The combined analysis of the two sequences formed 13 haplotypes (named Hap1-Hap13), and Hap4 is the main genotype, followed by Hap1. The unique haplotypes possessed by the three producing areas can be used as DNA molecular tags in this area to distinguish from the germplasm resources of P. grandiflorum from other areas. The haplotype diversity, nucleotide diversity and genetic distance were 0.94, 4.79×10^-3 and 0.000 0-0.020 3, respectively, suggesting that the genetic diversity was abundant and intraspecific kinship was relatively close. This study laid a foundation for the identification of P. grandiflorum, the protection and utilization of germplasm resources, and molecular breeding.