Tremella aurantialba polysaccharides alleviates ulcerative colitis in mice by improving intestinal barrier via modulating gut microbiota and inhibiting ferroptosis.

We aimed to investigate the effect of a polysaccharide from Tremella aurantialba on ulcerative colitis (UC), which targets ferroptosis in epithelial cells. TA 2-1 (127 kDa) was isolated from T. aurantialba and consisted of Man, Xyl, GlcA, Glc, Fuc and Rha with a molar ratio of 59.2: 23.2: 13.9: 1.6: 1.7: 0.4, exhibited a 1, 3-Man structure with branch chains of T-Xylp, 1,3-Xylp, 1,4-GlcAp, and T-Manp at its O-2 position. TA 2-1 (100 mg/mL) inhibited the cell viability of ferroptosis (19.8 %) in RLS3-induced Caco2 cells and significantly ameliorated symptoms in the colons of mice with dextran sodium sulfate (DSS)-induced UC. TA 2-1 remarkably repaired the intestinal barrier by upregulating claudin-1 and zonula occludens-1 levels. Further analysis found TA 2-1 significantly suppressed lipid peroxidation by regulating ferroptosis-related proteins in UC mice, suggesting that its protective effects are partially mediated by inhibiting ferroptosis. Further analysis of the gut microbiota and fecal microbiota transplantation revealed TA 2-1 might relieve UC symptoms or inhibit ferroptosis by modulating the gut microbiota's composition or metabolites. Results suggest the protective effects of TA 2-1 on the intestinal barrier by inhibiting ferroptosis of epithelial cells, at least by regulating the gut microbiota, highlighting the potential of TA 2-1 in UC treatment.

All-potassium channel CRISPR screening reveals a lysine-specific pathway of insulin secretion.

OBJECTIVE: Genome-scale CRISPR-Cas9 knockout coupled with single-cell RNA sequencing (scRNA-seq) has been used to identify function-related genes. However, this method may knock out too many genes, leading to low efficiency in finding genes of interest. Insulin secretion is controlled by several electrophysiological events, including fluxes of KATP depolarization and K+ repolarization. It is well known that glucose stimulates insulin secretion from pancreatic ß-cells, mainly via the KATP depolarization channel, but whether other nutrients directly regulate the repolarization K+ channel to promote insulin secretion is unknown. METHODS: We used a system involving CRISPR-Cas9-mediated knockout of all 83 K+ channels and scRNA-seq in a pancreatic ß cell line to identify genes associated with insulin secretion. RESULTS: The expression levels of insulin genes were significantly increased after all-K+ channel knockout. Furthermore, Kcnb1 and Kcnh6 were the two most important repolarization K+ channels for the increase in high-glucose-dependent insulin secretion that occurred upon application of specific inhibitors of the channels. Kcnh6 currents, but not Kcnb1 currents, were reduced by one of the amino acids, lysine, in both transfected cells, primary cells and mice with ß-cell-specific deletion of Kcnh6. CONCLUSIONS: Our function-related CRISPR screen with scRNA-seq identifies Kcnh6 as a lysine-specific channel.

Research on the value of quantitative evaluation system of medical equipment procurement in the management of hospital asset allocation / 中国医学装备

Objective:To establish a quantitative evaluation system for medical equipment procurement and to explore its application value in the allocation and management of hospital assets.Methods:Based on theoretical research and on-site evaluation,an evaluation index system was developed from four levels of clinical demand,technical level,procurement process and service capabilities.The quantitative evaluation of the procurement process was conducted by using covariance-analytic hierarchy process(Cov-AHP),and a"6-stage"optimization process of medical equipment procurement was developed.A total of 257 sets of medical equipment purchased by Beijing Shunyi Hospital from August 2019 to July 2023 were selected,and the expert demonstration model(126 units)and the quantitative evaluation model(131 units)were used for medical equipment asset allocation management.The standardization of the medical equipment procurement process,effectiveness of performance objectives and satisfaction of clinical services of medical equipment procurement under different management methods were compared.Results:The standardization degrees of the procurement process of the medical equipment in the quantitative evaluation model in terms of startup,demonstration,implementation,installation and use stages were(98.42±2.83)%,(98.97±2.45)%,(96.24±3.87)%,(96.42±2.54)% and(94.82±5.31)%,respectively,which were higher than those in the expert demonstration model,the difference was statistically significant(t=3.741,4.385,6.551,7.620,4.563,P<0.05).The achievement rates of quality index,progress index,social benefit index and cost-benefit index of medical equipment procurement in the quantitative evaluation model were(96.15±4.08)%,(96.41±2.37)%,(92.77±3.89)% and(93.06±4.33)%,respectively,which were higher than those in the expert demonstration model,the difference was statistically significant(t=4.156,4.562,5.014,4.069,P<0.05).The clinical satisfaction scores of medical equipment users of medical equipment in the quantitative evaluation model for large medical equipment,life support and first aid equipment,laboratory testing equipment,surgical treatment equipment and other medical equipment were(90.24±1.89)points,(93.45±2.64)points,(95.67±3.64)points and(93.82±2.55)points and(97.25±3.89)points,respectively,which were higher than those in the expert demonstration model,the difference was statistically significant(t=3.678,4.079,2.845,3.628,5.023,P<0.05).Conclusion:The quantitative evaluation system can standardize the procurement process of medical equipment,improve the achievement rate of the performance target of medical equipment procurement,and improve the clinical service level of medical equipment.

PIEZO1 Channel is Involved in Electric Field Guided Cell Migration / 生物化学与生物物理进展

ObjectiveDisruption of epithelial layer may instantaneously induce the generation of endogenous electric fields, which was proved to play an important role in guiding the cell migration and promoting wound healing. PIEZO1 is a kind of mechanic sensitive channel, may be regulated by voltage, is proved to involve in chemotactic migration of cells and play an important role in the process of wound healing. In this paper, the role of PIEZO1 and its downstream proteins FAK and integrin β1 in the electric field guided cell migration were investigated by HaCaT cells (human immortalized keratinocyte). MethodsCell migration was tracked by Living Cell Imaging System in directed current (DC) electric field (EF). Inhibitors and RNAi techniques were applied to study the function of PIEZO1 and other related proteins in electric fields. Western blot was used to detect the expression and phosphorylation levels of integrin β1 and FAK in electric field guided migration under EF stimulation. ResultsPiezo1 RNAi as well as Ruthenium red and GsMTx4 treatment all significantly inhibited the electrotaxis of HaCaT cells. Electric field stimulation with GsMTx4 treatment alone increased FAK phosphorylation level and the expression of integrin β1. Electric field promoted the expression level of integrin β1 and the phosphorylation level of FAK. Inhibiting the expression of PIEZO1 by RNAi significantly attenuated the phosphorylation level of FAK under EF stimulation. Inhibition of integrin β1 and FAK by inhibitor significantly decrease the electric field guided cell migration. ConclusionPIEZO1 as well as integrin β1 and FAK are involved in the electric field guided cell migration of HaCaT cells. Electric field signals regulate the expression of integrin β1 and the activation of FAK through PIEZO1-mediated signal pathway to orchestrate cell migration.

Polysaccharides: potential bioactive macromolecules for Alzheimer's disease.

Alzheimer's disease (AD) is one of the leading causes of death and disability. AD is a devastating disease that has caused an overwhelming burden. However, no disease-modified treatment was discovered. The approval of sodium oligomannate (GV-971) in mild-moderate AD patients has attracted great attention to investigate the role of saccharides in AD. Therefore, summarizing and explaining the role of saccharides in AD is urgent and promising. Recent studies showed that polysaccharides (PSs) potentially benefit AD in vitro and in vivo. PSs could alleviate the pathological damage and improve cognitive symptoms via (1) antagonizing the toxicity of abnormal amyloid-beta and tau proteins; (2) attenuating oxidative stress and proinflammation; (3) rebuilding neuroplasticity. PSs exhibit one-multiple pathological hits of AD. However, a thorough chemical investigation is needed for further study.

Pseudolaric acid B triggers cell apoptosis by activating AMPK/JNK/DRP1/mitochondrial fission pathway in hepatocellular carcinoma.

Pseudolaric acid B (PAB), a natural product isolated from the root bark of Pseudolarix kaempferi, has been reported to exert inhibitory effects in various cancers. However, the underlying mechanisms remain largely unclear. In the present study, we investigated the mechanism through which PAB exert its anticancer effects in hepatocellular carcinoma (HCC). PAB inhibited the viability of and induced apoptosis in Hepa1-6 cells in a dose-dependent manner. It disrupted mitochondrial membrane potential (MMP) and impaired ATP production. Furthermore, PAB induced phosphorylation of DRP1 at Ser616 and mitochondrial fission. Blocking DRP1 phosphorylation by Mdivi-1 inhibited mitochondrial fission and PAB-induced apoptosis. Moreover, c-Jun N-terminal kinase (JNK) was activated by PAB, and blocking JNK activity using SP600125 inhibited PAB-induced mitochondrial fission and cell apoptosis. Furthermore, PAB activated AMP-activated protein kinase (AMPK), and inhibiting AMPK by compound C attenuated PAB-stimulated JNK activation and blocked DRP1-dependent mitochondrial fission and apoptosis. Our in vivo data confirmed that PAB inhibited tumor growth and induced apoptosis in an HCC syngeneic mouse model by inducing the AMPK/JNK/DRP1/mitochondrial fission signaling pathway. Furthermore, a combination of PAB and sorafenib showed a synergistic effect in inhibiting tumor growth in vivo. Taken together, our findings highlight a potential therapeutic strategy for HCC.

[Regulation mechanism of resveratrol on odontogenic differentiation of human dental pulp stem cells].

PURPOSE: To investigate whether resveratrol promotes odontogenic differentiation of human dental pulp stem cells(DPSCs) by up-regulating the expression of silent information regulator 1 (SIRT1) and activating ß-catenin signaling pathway. METHODS: Different concentrations of resveratrol(0, 10, 15, 20 and 50 µmol/L) were used to treat DPSCs for 7 days and 14 days, and cell proliferative activity was detected by CCK-8. After odontogenic differentiation induced by 15 µmol/L resveratrol for 7 days, alkaline phosphatase(ALP) staining was performed and real-time quantitative reverse transcription PCR(qRT-PCR) was used to detect the mRNA expression of Runt-related transcription factor 2 (Runx2), dentin sialophosphoprotein(DSPP) and dentin matrix protein-1(DMP-1) in DPSCs. Western blot was used to detect the expression of SIRT1 in DPSCs on a specific day (0, 3rd, 5th, 7th and 14th) after differentiation induction. Western blot was also used to detect the expression of SIRT1 and activated ß-catenin during odontogenic differentiation of DPSCs treated by 15 µmol/L resveratrol for 7 days. The experimental data was analyzed with GraphPad Prism 9 software package. RESULTS: 15 µmol/L resveratrol had no significant effect on proliferation of DPSCs on the 7th and 14th day; 15 µmol/L resveratrol promoted odontogenic differentiation of DPSCs and up-regulated mRNA expression of RUNX2, DSPP, and DMP-1 in DPSCs; the expression of SIRT1 was the highest on the 7th day during odontogenic differentiation induction. Resveratrol resulted in the increasing protein expressions of SIRT1 and activated ß-catenin when DPSCs was induced to odontogenic differentiation for 7 days. CONCLUSIONS: Resveratrol promotes odontogenic differentiation of human DPSCs by up-regulating the expression of SIRT1 protein and activating ß-catenin signaling pathway.

[Effects of chitosan oligosaccharide on bone metabolism and IKK/NF-κB pathway in rats with osteoporosis and periodontitis].

PURPOSE: To investigate the effects of chitosan oligosaccharide on bone metabolism and IKK/NF-κB pathway in mice with osteoporosis and periodontitis. METHODS: Thirty rats were randomly divided into 3 groups, with 10 rats in each group. They were divided into control group, ovariectomized periodontitis group and chitosan oligosaccharide treatment group. Except for the control group, the other two groups were ovariectomized and smeared with Porphyromonas gingivalis fluid to establish the model of osteoporosis with periodontitis. Four weeks after ligation, the rats in chitosan oligosaccharide treatment group were gavaged with 200 mg/kg chitosan oligosaccharide, and the other two groups were gavaged with equal volume of normal saline once a day for 90 days. The periodontal tissues of each group were observed before administration, and the bone mineral density of rats was detected by dual energy X-ray animal bone mineral density and body composition analysis system. After 90 days of administration, the bone mineral density was detected again. After administration, blood was collected from tail vein, and the contents of serum alkaline phosphatase (ALP), bone Gla protein (BGP) and tartrate resistant acid phosphatase 5b (TRACP5b) were measured by enzyme-linked immunodeficient assay. The gingival index and periodontal attachment loss of rats in each group were obtained by visual examination and exploratory examination. The maxilla was removed, and the distance from the enamel cementum boundary to the alveolar crest was measured to obtain alveolar bone absorption value. H-E staining was used to observe the pathology of maxilla in each group. RT-PCR and Western blot were used to detect the nuclear factors in periodontal tissue of rats in each group. SPSS 22.0 software package was used for statistical analysis. RESULTS: Before administration, the gums of the control group were pink without bleeding, and the gums of the other two groups were red and swollen with slight bleeding. After administration, compared with the control group, the bone mineral density, serum ALP, BGP of ovariectomized periodontitis group decreased significantly(P＜0.05); while TRACP5b, gingival index, loss of periodontal attachment and alveolar bone resorption, NF-κB and IKK mRNA and protein expression in periodontal tissue increased significantly(P＜0.05). Compared with the ovariectomized periodontitis group, the bone mineral density, serum ALP, BGP were significantly increased(P＜0.05); while TRACP5b, gingival index, periodontal attachment loss and alveolar bone resorption, NF-κB and IKK mRNA and protein expression in periodontal tissue were significantly decreased (P＜0.05). In the ovariectomized periodontitis group, the periodontal tissue combined with epithelium was separated from the tooth surface, the dental pocket was obvious and deep, and the height of alveolar bone decreased. Although dental pocket could be observed in the periodontal tissue of rats treated with chitosan oligosaccharide, it was not obvious, and new bone appeared around the alveolar bone. CONCLUSIONS: Chitosan oligosaccharide can induce biochemical indexes of bone metabolism to become normal, alleviate the symptoms of periodontitis, this may be related to the inhibition of IKK/NF-κB pathway by chitosan oligosaccharide.

Content determination of seven active components of Eucommiae Cortex in aortic vascular endothelial cells of spontaneously hypertensive rats by UPLC-MS/MS / 中国中药杂志

In the present study, the contents of seven active components [genipinic acid(GA), protocatechuic acid(PCA), neochlorogenic acid(NCA), chlorogenic acid(CA), cryptochlorogenic acid(CCA),(+)-pinoresinol di-O-β-D-glucopyranosid(PDG), and(+)-pinoresinol 4'-O-β-D-glucopyranoside(PG)] of Eucommiae Cortex in aortic vascular endothelial cells of spontaneously hypertensive rats(SHR) were simultaneously determined by ultra-high liquid chromatography-triple quadrupole mass spectrometry(UPLC-MS/MS). The qualified SHR models were selected. The primary aortic endothelial cells(VECs) of rats were separated and cultured by ligation and adherence, followed by subculture. After successful identification, an UPLC-MS/MS method for simultaneously determining the contents of GA, PCA, NCA, CA, CCA, PDG, PG in seven components of Eucommiae Cortex in VECs was established, including specificity, linearity, matrix effect, recovery, accuracy, precision and stability. The established method had the lo-west limit of quantification of 0.97-4.95 μg·L~(-1), accuracy of 87.26%-109.6%, extraction recovery of 89.23%-105.3%, matrix effect of 85.86%-106.2%, and stability of 86.00%-112.5%. Therefore, the established accurate UPLC-MS/MS method could rapidly and simultaneously determine the contents of the seven active components of Eucommiae Cortex in VECs of SHRs, which provided a refe-rence for the study of cellular pharmacokinetics of active components of Eucommiae Cortex extract.

Determination of plasma protein binding rate of Shuganning Injection using equilibrium dialysis and UPLC-MS/MS / 中国中药杂志

Traditional Chinese medicine(TCM) compound preparations have complex compositions. As a widely used TCM injection, Shuganning Injection, its in vivo processes are not yet fully understood. Determining the plasma protein binding rate is of great significance for pharmacokinetic and pharmacodynamic studies. In this experiment, the equilibrium dialysis method combined with UPLC-MS/MS technology was used to determine the plasma protein binding rates of 10 components, including p-hydroxyacetophenone, caffeic acid, baicalein, oroxylin A, geniposide, baicalin, cynaroside, oroxylin A-7-O-β-D-glucuronide, scutellarin, and hyperoside, in Shuganning Injection in rat and human plasma to provide a theoretical basis for further elucidating the in vivo processes of Shuganning Injection and guiding clinical medication. The results showed that, except for baicalein and geniposide, the plasma protein binding rates of the other eight components were higher in human plasma than in rat plasma, and there were interspecies differences. In human plasma, except for geniposide, caffeic acid, and baicalin, the plasma protein binding rates of the remaining seven components were above 80%, with baicalein and oroxylin A exceeding 90%. All components exhibit a high level of binding to plasma proteins, with the exception of geniposide.

Simultaneous determination of eleven volatile components in Cinnamomi Oleum by GC-MS / 中国中药杂志

A gas chromatography-triple quadrupole mass spectrometry(GC-MS) method was established for the simultaneous determination of eleven volatile components in Cinnamomi Oleum and the chemical pattern recognition was utilized to evaluate the quality of essential oil obtained from Cinnamomi Fructus medicinal materials in various habitats. The Cinnamomi Fructus medicinal materials were treated by water distillation, analyzed using GC-MS, and detected by selective ion monitoring(SIM), and the internal standards were used for quantification. The content results of Cinnamomi Oleum from various batches were analyzed by hierarchical clustering analysis(HCA), principal component analysis(PCA), and orthogonal partial least squares-discriminant analysis(OPLS-DA) for the statistic analysis. Eleven components showed good linear relationships within their respective concentration ranges(R~2>0.999 7), with average recoveries of 92.41%-102.1% and RSD of 1.2%-3.2%(n=6). The samples were classified into three categories by HCA and PCA, and 2-nonanone was screened as a marker of variability between batches in combination with OPLS-DA. This method is specific, sensitive, simple, and accurate, and the screened components can be utilized as a basis for the quality control of Cinnamomi Oleum.

Value and research progress of BRAFV600E mutation in the diagnosis and treatment of thyroid carcinoma / 国际外科学杂志

Thyroid Carcinoma, as one of the most common malignant tumors in the endocrine system and head and neck, has a rising incidence rate in the world in recent years, which seriously affects human health. Thyroid carcinoma is often divided into 4 pathological types: papillary carcinoma, follicular carcinoma, medullary carcinoma and undifferentiated carcinoma. Among them, papillary carcinoma is the most common with low malignancy and undifferentiated carcinoma is extremely rare with the highest malignancy. BRAFV600E mutation has been found to be closely related to the genesis, development mechanism and prognosis of thyroid carcinoma, and is a current molecular research focus. Clinically, BRAFV600E mutation is often considered as a molecular marker affecting the prognosis of thyroid carcinoma. In this paper, the relevant literature in recent years was reviewed, mainly from the aspects of BRAFV600E mutation and thyroid carcinoma diagnosis, clinicopathological features, guidance of clinical treatment decision, prognosis and so on, to evaluate the clinical application value of BRAFV600E mutation.

Compatibility stability of cinepazide maleate injection and dopamine hydrochloride injection / 中国基层医药

Objective:To investigate the compatibility stability of cinepazide maleate injection and dopamine hydrochloride injection and explore the basis for the combined application of cinnamazide maleate injection and dopamine hydrochloride injection.Methods:A method for determining cinnamazide maleate injection and dopamine hydrochloride injection was established using an ultraviolet-visible spectrophotometer and verified from March 1, 2021 to May 20, 2021. The color and pH value of the solution prepared using the two drugs were determined within 5 hours at room temperature. The content change of the prepared solution was determined using an ultraviolet-visible spectrophotometer.Results:The linear range of the mass concentration of cinnamazide maleate was 4.03 - 32.24 mg/L and the linear range of dopamine hydrochloride was 20 -120 mg/L. At 25 ℃, the color of the prepared solution did not change within 5 hours and the pH value was in the range of 4.43 ± 0.06, indicating that the pH of the prepared solution did not change markedly. The concentrations of cinnamazide maleate and dopamine hydrochloride were (98.23 ± 1.09)% and (99.96 ± 0.41)% respectively, indicating good stability.Conclusion:The prepared solution using cinepazide maleate injection and dopamine hydrochloride injection can be used within 5 hours at 25 ℃.

Effects of different light sources on the stability of cinepazide maleate in sodium chloride solution / 中国基层医药

Objective:To investigate the effects of different light sources on the stability of cinepazide maleate in sodium chloride solution, providing a theoretical basis for standardizing operation for avoiding light in clinical medication.Methods:First, a standard curve was created and methodological studies were conducted. Then, intravenous drip solutions were prepared using clinically prescribed methods. Then, the absorbance of the solution of cinepazide maleate injection under outdoor light, light emitting diode (LED) light, indoor light, artificial sunlight with a color temperature of 6 500 K (D65), and under a shading condition for 1, 2, 3, and 7 hours were brought into the standard curve to obtain the concentrations, and the change of the concentrations was studied.Results:There was no light decomposition phenomenon of cinepazide maleate injection in the shading group (control group) within 7 hours. In the other four experimental groups, there was no obvious light decomposition phenomenon of cinepazide maleate injection in the LED light group. Compared with the shading group, cinepazide maleate injection in the indoor, outdoor, and D65 groups began to exhibit a light decomposition phenomenon at 1 hour ( F = 44 840.44, P < 0.001). At 2 hours, cinepazide maleate content in the outdoor and D65 groups began to decrease significantly compared with the shading group ( F = 15 459.12, P < 0.001). At 7 hours, cinepazide maleate exhibited significantly greater light decomposition in the outdoor group [(29.84 ± 0.43) L·mol -1·cm -1] and D65 group [(21.01 ± 0.51) L·mol -1·cm -1] than the shading group [(101.65 ± 1.5) L·mol -1·cm -1] ( F = 63 106.32, P < 0.001). There was no significant difference in cinepazide maleate content between LED and shading groups ( P > 0.05). Conclusion:Cinepazide maleate injection is stable under the common LED light source and therefore it is not necessary to take lightproof operation. Cinepazide maleate injection is unstable under indoor, outdoor, and D65 light sources, and it is necessary to take lightproof operation.

Adverse event analysis and renal safety comparison of tenofovir disoproxil and tenofovir alafenamide based on FAERS database / 药物流行病学杂志

Objective To explore the adverse events and renal safety of tenofovir disoproxil(TD)and tenofovir alafenamide(TA)by data mining from the U.S.Food and Drug Administration Adverse Event Reporting System(FAERS)database,so as to provide reference for clinical drug safety.Methods The adverse events of TD and TA reported in FAERS database between the first quarter of 2004 and the first quarter of 2023 were analyzed with the methods of the reporting odds ratio(ROR)method,proportional reporting ratio(PRR)method,the Medicines and Healthcare products Regulatory Agency(MHRA)method,and Bayesian Confidence Propagation Neural Network(BCPNN)method.The distribution and intensity of risk signals of the data were analyzed,and the SMQ search tool was employed to conduct in-depth analysis of"acute renal failure"and"chronic kidney disease".Results A total of 19 530 and 1 587 reports were extracted as primary suspect drugs for TD and TA.There were more males than females were found in reports,and the age was concentrated in 45-65 years old,and the number of signals satisfying the four excavation methods was 185 and 68,respectively.The high-frequency adverse event distribution showed significant differences between TD and TA.The main risk signals of TD were bone and renal diseases,manifested as decreased bone density,bone injury,osteoporosis,chronic kidney disease,and renal failure.The main risk signals of TA was systemic disease with few reports of bone and renal damage,most of which were negative signals.Further analysis of renal safety showed similar results.Conclusion There are certain differences in terms of high-frequency adverse events,systemic organ distribution,and overall safety between TD and TA,especially the safety of renal and bone.Patients with pre-existing renal and bone diseases prefer TA to TD,however,the short time to market and the deviation caused by the small number of reports for TA,the safety of the two drugs should be continuously paid attention to.

Simultaneous determination of content of eight components in Caesalpinia decapetala by UPLC-MS/MS / 中国中药杂志

The present study established the ultra-high performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS) method for simultaneous determination of the content of eight major active components in Caesalpinia decapetala and performed the quality evaluation of C. decapetala from different habitats with the chemical pattern recognition. The analysis was carried out on a Waters BEH C_(18) column(2.1 mm×100 mm, 1.7 μm) at 40 ℃, with the mobile phase of water containing 0.1% formic acid(A) and acetonitrile containing 0.1% formic acid under gradient elution, the flow rate of 0.3 mL·min~(-1), and the injection volume of 1 μL. The electrospray ionization(ESI) source in the negative mode and multiple reaction monitoring(MRM) were used for MS quantitative analysis. The content results were analyzed by the hierarchical cluster analysis(HCA) and principal component analysis(PCA) for the evaluation of the quality difference. Eight components showed good linear relationships within their respective concentration ranges(r>0.999), with the average recoveries of 96.85%-103.4% and RSD of 0.52%-2.8%. The analysis results showed that the quality of samples from different batches was different. The samples were classified into three clusters by HCA and PCA. The method is simple, sensitive, accurate, and efficient, and can be used for the quality evaluation of C. decapetala.

The two-stage interaction of Ebola virus VP40 with nucleoprotein results in a switch from viral RNA synthesis to virion assembly/budding

Ebola virus (EBOV) is an enveloped negative-sense RNA virus and a member of the filovirus family. Nucleoprotein (NP) expression alone leads to the formation of inclusion bodies (IBs), which are critical for viral RNA synthesis. The matrix protein, VP40, not only plays a critical role in virus assembly/budding, but also can regulate transcription and replication of the viral genome. However, the molecular mechanism by which VP40 regulates viral RNA synthesis and virion assembly/budding is unknown. Here, we show that within IBs the N-terminus of NP recruits VP40 and is required for VLP-containing NP release. Furthermore, we find four point mutations (L692A, P697A, P698A and W699A) within the C-terminal hydrophobic core of NP result in a stronger VP40-NP interaction within IBs, sequestering VP40 within IBs, reducing VP40-VLP egress, abolishing the incorporation of NC-like structures into VP40-VLP, and inhibiting viral RNA synthesis, suggesting that the interaction of N-terminus of NP with VP40 induces a conformational change in the C-terminus of NP. Consequently, the C-terminal hydrophobic core of NP is exposed and binds VP40, thereby inhibiting RNA synthesis and initiating virion assembly/budding.