In sight the behavior of natural Bletilla striata polysaccharide hydrocolloids by molecular dynamics method.

Plant polysaccharides, distinguished by diverse glycosidic bonds and various cyclic sugar units, constitute a subclass of primary metabolites ubiquitously found in nature. Contrary to common understanding, plant polysaccharides typically form hydrocolloids upon dissolution in water, even though both excessively high and low temperatures impede this process. Bletilla striata polysaccharides (BSP), chosen for this kinetic study due to their regular repeating units, help elucidate the relationship between polysaccharide gelation and temperature. It is suggested that elevated temperatures enhance the mobility of BSP molecular chains, resulting in a notable acceleration of hydrogen bond breakage between BSP and water molecules and consequently, compromising the conformational stability of BSPs to some extent. This study unveils the unique relationship between polysaccharide dissolution processes and temperature from a kinetics perspective. Consequently, the conclusion provides a dynamical basis for comprehending the extraction and preparation of natural plant polysaccharide hydrocolloids, pharmaceuticals and related fields.

The comparative analysis of Lonicerae Japonicae Flos and Lonicerae Flos: A systematical review.

ETHNOPHARMACOLOGICAL RELEVANCE: Lonicerae Japonicae Flos (LJF) and Lonicerae Flos (LF) were once used as the same herb in China, but they were distinguished by Chinese Pharmacopoeia in 2005 in terms of their medicinal history, plant morphology, medicinal properties and chemical constituents. However, their functions, flavor, and meridian tropism are the same according to the Chinese pharmacopoeia 2020 edition, making researchers and customers confused. AIM OF THE REVIEW: This review aimed to provide a comparative analysis of LJF and LF in order to provide a rational application in future research. MATERIALS AND METHODS: The information was gathered from China National Knowledge Infrastructure (CNKI), SciFinder, Google Scholar, PubMed, Web of Science, and Chinese Masters and Doctoral Dissertations (all chosen articles were reviewed attentively from 1980.1 to 2023.8). RESULTS: Till now, 507 chemical compounds have been isolated and identified in LJF, while 223 ones (79 overlapped compounds) are found in LF, including organic acids and derivatives, flavonoids, triterpenoids, iridoids, and essential oil components, etc. In addition, the pharmacological activities of LJF and LF, especially for their anti-influenza efficacy and mechanism, and their difference in terms of pharmacokinetic parameters, toxicology, and clinical applications were also summarized. CONCLUSION: The current work offers comparative information between LJF and LF in terms of botany, traditional uses, phytochemistry, ethnopharmacology, pharmacokinetics, toxicology, and pharmacology, especially their anti-influenza activities. Despite the same clinical applications and similar chemical components in LJF and LF, differentiated components were still existed, resulting in differentiated pharmacological activities and pharmacokinetics parameters. Moreover, the research about anti-influenza mechanism and functional substances of LJF and LF is dramatically limited, restricting their clinical applications. In addition, few studies have investigated the metabolism feature of LF in vivo, which is one of the important bases for revealing the pharmacological mechanism of LF. At the same time, the toxicity of LJF and LF is not fully studied, and the toxic compounds of LJF and LF need to be screened out in order to standardize the drug use and improve their rational applications.

Ex Vivo Pharmacokinetics and Pharmacodynamics Modeling and Optimal Regimens Evaluation of Cefquinome Against Bovine Mastitis Caused by Staphylococcus aureus.

Cefquinome, the fourth-generation cephalosporin applied solely for veterinary medicine, is commonly used for bovine mastitis caused by Staphylococcus aureus. The present study aims to establish an optimal dose and provide a PK/PD Cutoff value (COPD) for cefquinome against S. aureus based on ex vivo pharmacokinetics and pharmacodynamics (PK/PD) integration. This study investigated the pharmacokinetics (PK) of cefquinome when administered as three consecutive intramammary (IMM) doses of cefquinome in three healthy dairy cows at 75 mg/gland. Drug concentration was determined by HPLC-MS/MS assay. The ex vivo pharmacodynamics (PD) of cefquinome were evaluated by using a milk sample from a PK experiment. The relationship between the AUC/ MIC of cefquinome and bacterial loading reduction was simulated using a Sigmoid Emax model. The cefquinome concentration in milk attained a maximum level of 1.55 ± 0.21 mg/mL at 1.8 h after the third administration. The mean value of the area under the concentration-time curve (AUC0-24) was 26.12 ± 2.42 mg·h/mL after the third administration. The elimination half-life was 10.6 h. For PD profile, the MICs of cefquinome in milk were 2-4 times higher than those in the broth. In vitro time-killing curve shows that initial bacterial concentration has a huge impact on antibacterial effect on three strains. The antibacterial effect was weakened with the initial bacterial concentration increasing from 106 to 108 CFU/mL. The AUC0-24h/MIC index correlated well with ex vivo efficacy both for the initial inoculum of 106 CFU/mL and 108 CFU/mL (R 2 > 0.84). According to the inhibitory sigmoid Emax model analysis, the PK/PD surrogate (AUC0-24/MIC) values were 8,638, 1,397, and 3,851 for bactericidal effect (E = -3) with an initial inoculum of 106 CFU/mL, while the corresponding values were 12,266, 2,295, and 5,337, respectively, with the initial inoculum of 108 CFU/mL. The ex vivo PK/PD based population dose prediction indicated a target attainment rate (TAR) of 90% of 55 mg/gland/12 h. The COPD for cefquinome against S. aureus was 2 µg/mL under the recommended dose of 55 mg/gland/12 h. However, it should be validated in clinical practice in future investigations. These results contribute to the rational use of cefquinome for mastitis treatment in clinical veterinary medicine.

[Systematic review and meta-analysis of acupuncture and moxibustion: existing problems and countermeasures].

There are some common problems in the systematic review and meta-analysis on acupuncture-moxibustion, e.g. indistinct definition and errors in methodology. In order to further improve the quality of relevant literature, in association with the characteristics of acupuncture-moxibustion, based on the framework of PICOS (P: population, I: interventions, C: comparisons, O: outcomes, S: study designs), the paper explores how to construct specific research questions. In methodology, the paper analyzes the common problems from five aspects, including literature retrieval, bias assessment, analysis and interpretation of results, selection of other types of meta-analysis and the update of methodology. Based on the analysis above, the paper discusses the corresponding countermeasures.

Study on syndrome differentiation strategy of phlegm and blood stasis syndromes of coronary heart disease based on expert consultation on medical cases.

BACKGROUND: It is becoming more and more important to judge whether patients with coronary heart disease (CHD) have phlegm and blood stasis syndromes in the process of traditional Chinese medicine (TCM) diagnosis and treatment of CHD. The syndrome differentiation strategy of phlegm and blood stasis syndromes of CHD is still not standardized, and it is particularly necessary to make syndrome differentiation simpler and more accurate. METHODS: Twenty-eight medical cases that met the criteria, comprising 10 ancient medical cases and 18 modern ones, were selected from the TCM literature, which were then analyzed by 57 experts via questionnaire. Statistical analysis of the data was mainly based on frequency analysis. RESULTS: (I) The average age of the 57 experts from 20 provinces was 48.9±8.5 years; 89.5% were associate professor or above, and 75.4% of them worked at a tertiary hospital. (II) Consistency of expert consultation over medical cases: for the ancient medical cases, the diagnostic consistency rate of phlegm syndrome was 27/34 (79.4%) and additional diagnosis rate of the blood stasis syndrome was 27/57 (47.4%); for the modern medical cases, the consistency rate compared with the original diagnosis of phlegm syndrome was 54/80 (67.5%) and that of blood stasis syndrome was 73/90 (81.1%). (III) The top five experts' diagnostic basics of phlegm syndrome were oppression in the chest, slippery pulse, greasy fur, coughing of phlegm, and chest pain; the top five diagnostic basics of blood stasis syndrome were chest pain, dark tongue, oppression in chest, red tongue, and ecchymosis on tongue. (IV) In the questionnaire consultation on CHD phlegm-blood stasis syndrome cases, the diagnostic basis of "symptom or (and) tongue manifestation" accounted for 12/27 (44.4%) of the diagnostic basics of phlegm syndrome and 28/38 (73.7%) of that of blood stasis syndrome basis. CONCLUSIONS: Modern Chinese medicine experts pay much attention to the diagnosis and treatment of CHD based on TCM pathology theories of phlegm and blood stasis. To collect and detect the patients' symptoms and tongue manifestation is an important strategy of the experts for CHD phlegm and blood stasis syndrome differentiation.

Proteomics profiling of epithelium-derived exosomes from nasal polyps revealed signaling functions affecting cellular proliferation.

BACKGROUND: Nasal polyps are a significantly associated pathology of chronic rhinosinusitis (CRS) whose mechanisms of pathogenesis are not fully elucidated, especially the interaction of the polyp with its environment that allows its growth on the nasal epithelial lining. Exosomes are nanovesicles that serve important biological functions, including cell-to-cell signaling and communication. OBJECTIVE: Hence, we sought to explore the roles of the epithelial-derived exosomal proteome obtained from the human nasal epithelium in the modulation of CRS with nasal polyp (CRSwNP) pathogenesis. METHODS: We sampled exosomes from nasal lavage fluid and primary human nasal epithelial cells (hNECs) from healthy controls and patients with CRSwNP with and without coexisting asthma. The presence of exosomes was confirmed using a NanoSight assay, transmission electron microscopy and western blotting. The exosomal proteome was profiled with mass spectrometry. The Cell Counting Kit-8 was used to confirm the roles of exosomes in mediating cellular proliferation. RESULTS: The hNEC-derived exosomes from diseased epithelium contained differentially expressed proteins that were mainly involved in epithelial remodeling via pathways such as p53. An in vitro study further demonstrated that epithelial-derived exosomes from patients with CRSwNP (with and without coexisting asthma) significantly reduced the rate of proliferation of control hNECs at an effective concentration of ≥10 µg/ml. CONCLUSIONS: Exosomes secreted by hNECs from patients with CRSwNP, regardless of their coexistence with asthma, are laden with proteins that influence cell proliferation pathways, potentially leading to remodeling of the sinonasal mucosa.

Effect of Cellulose Powder on Human Nasal Epithelial Cell Activity and Ciliary Beat Frequency.

BACKGROUND: Cellulose powder (CP) has been reported as a safe and effective complementary treatment for allergic rhinitis (AR). Currently, CP has gained increasing application for clinical management worldwide, particularly in China. However, studies focusing on the effect of CP on normal human nasal epithelial cells (hNECs) and ciliary function are lacking. Here, we aimed to explore the adverse effects of CP on the activity and ciliary function of hNECs. METHODS: We biopsied ethmoid sinus or middle turbinate tissues during surgical resection from control subjects who underwent endoscopic sinus surgery for diseases other than AR. Cells were isolated and passaged, followed by differentiation in an air-liquid interface (ALI). Flow cytometry and cell viability test (cell counting kit-8) were performed to detect the cytotoxicity of CP (effects on cell proliferation) on normal hNECs. By using the ALI culture model, we investigated the effects of CP on ciliary beat frequency (CBF). RESULTS: There was a significant reduction in hNEC count at high concentrations of CP (2.5 mg/mL) at days 3 and 7 (both p < 0.05). As the concentration increased, cell death increased progressively from day 3 to day 7. However, these effects were not evident at low concentrations (0.25 mg/mL, p > 0.05). High-dose CP (2.5 mg) significantly reduced the CBF (p < 0.05). At lower concentrations (0.25-2.5 mg/mL), CP initially increased but subsequently reduced the CBF of hNECs compared with control group. CONCLUSIONS: Cytotoxicity and the suppression of ciliary beat at high concentrations justify more prudent use of CP for the management of AR.

Elevated expression of IL-17RB and ST2 on myeloid dendritic cells is associated with a Th2-skewed eosinophilic inflammation in nasal polyps.

BACKGROUND: Interleukin(IL)-25, IL-33, and thymic stromal lymphopoietin (TSLP) underlie the crosstalk between epithelial cells and dendritic cells (DCs) during the development of Th2 responses. This study aimed to measure the expressions of IL-17RB, ST2 and TSLPR, receptor of IL-25, IL-33, and TSLP respectively, on myeloid DCs in nasal polyps (NP) and evaluate their association with local Th2 inflammation and disease severity in patients with NP. METHODS: Samples were collected from 30 NP patients and 16 control subjects recruited prospectively. The mRNA expression of cytokines, including TSLP, IL-25 and IL-33, as well as interferon (IFN)-γ, IL-4, IL-5, IL-13 and IL-17A in NP and control tissues was examined by qualitative polymerase chain reaction (qPCR). The expression of IL-17RB, ST2 and TSLPR as well as other surface markers on myeloid DCs (mDCs) was examined by flow cytometry. RESULTS: Increased numbers of total and activated mDCs were found in NP patients. mDCs demonstrated significantly higher expression of IL-17RB, ST2 and TSLPR than those in control tissues. The activated mDCs exhibited up-regulations of OX40L and ICOSL, but down-regulation of PDL1 in NP. Moreover, the IL-17RB, ST2 and TSLPR levels on mDCs were positively correlated with IL-25, IL-33 and TSLP mRNA levels, respectively, in NP. Furthermore, IL-17RB and ST2 expressions on mDCs were correlated with the IL-5 mRNA level as well as eosinophil number in NP. Importantly, the IL-17RB expression on mDCs and the OX40L expression on activated mDCs in NP were positively correlated with CT score and total nasal symptom score. CONCLUSIONS: Increased expressions of IL-17RB and ST2 on mDCs are associated with enhanced local Th2 inflammation in NP, suggesting that mDCs might play a role in IL-25- and IL-33-induced type 2 responses and eosinophilic inflammation in NP.

In Vivo Pharmacokinetic/Pharmacodynamic Profiles of Danofloxacin in Rabbits Infected With Salmonella typhimurium After Oral Administration.

Salmonella typhimurium is a highly transmissible pathogen in rabbits that causes significant losses. Danofloxacin shows excellent efficacy against S. typhimurium infections. However, there are few reports of the pharmacokinetic/pharmacodynamic (PK/PD) modeling of danofloxacin against this pathogen. The aim of this study was to evaluate the in vivo PK/PD relationship of danofloxacin in rabbits infected with S. typhimurium. We used the reduction of bacterial burden in the blood, liver, spleen, and lung as the target PD endpoints, and determined the PK/PD indexes that best correlated with the efficacy and its corresponding magnitude. Danofloxacin was administrated orally to experimentally S. typhimurium-infected rabbits once daily for three successive days. The concentrations of danofloxacin in the serum and the bacterial burden in the blood, liver, spleen, and lung were determined. The PK/PD relationships of danofloxacin against S. typhimurium were evaluated using a Sigmoid Emax model. The results showed that the area under the concentration-time curve from 0 to 24 h/minimum inhibitory concentration (AUC24 h/MIC) ratio correlated well with the in vivo antibacterial effectiveness in different organs, with an r2 of 0.8971, 0.9186, 0.9581, and 0.8708 in the blood, liver, spleen, and lung, respectively. The AUC24 h/MIC ratios for the bactericidal effect (3 × Log10 colony forming units/mL reductions) were 121.30, 354.28, 216.64, and 228.66 in the blood, liver, spleen, and lung, respectively, indicating that the in vivo effectiveness of danofloxacin against S. typhimurium using bacterial reduction in different organs as PD endpoints was not identical. This study illustrated that the selection of the target organ for bacterial reduction determination had little effect on best PK/PD parameter determination, but is critical for parameter magnitude calculation in antimicrobial PK/PD modeling, and furthermore, has an impact on the rational dosage optimization process.

Integrated Modules Analysis to Explore the Molecular Mechanisms of Phlegm-Stasis Cementation Syndrome with Ischemic Heart Disease.

Background: Ischemic heart disease (IHD) has been the leading cause of death for several decades globally, IHD patients usually hold the symptoms of phlegm-stasis cementation syndrome (PSCS) as significant complications. However, the underlying molecular mechanisms of PSCS complicated with IHD have not yet been fully elucidated. Materials and Methods: Network medicine methods were utilized to elucidate the underlying molecular mechanisms of IHD phenotypes. Firstly, high-quality IHD-associated genes from both human curated disease-gene association database and biomedical literatures were integrated. Secondly, the IHD disease modules were obtained by dissecting the protein-protein interaction (PPI) topological modules in the String V9.1 database and the mapping of IHD-associated genes to the PPI topological modules. After that, molecular functional analyses (e.g., Gene Ontology and pathway enrichment analyses) for these IHD disease modules were conducted. Finally, the PSCS syndrome modules were identified by mapping the PSCS related symptom-genes to the IHD disease modules, which were further validated by both pharmacological and physiological evidences derived from published literatures. Results: The total of 1,056 high-quality IHD-associated genes were integrated and evaluated. In addition, eight IHD disease modules (the PPI sub-networks significantly relevant to IHD) were identified, in which two disease modules were relevant to PSCS syndrome (i.e., two PSCS syndrome modules). These two modules had enriched pathways on Toll-like receptor signaling pathway (hsa04620) and Renin-angiotensin system (hsa04614), with the molecular functions of angiotensin maturation (GO:0002003) and response to bacterium (GO:0009617), which had been validated by classical Chinese herbal formulas-related targets, IHD-related drug targets, and the phenotype features derived from human phenotype ontology (HPO) and published biomedical literatures. Conclusion: A network medicine-based approach was proposed to identify the underlying molecular modules of PSCS complicated with IHD, which could be used for interpreting the pharmacological mechanisms of well-established Chinese herbal formulas (e.g., Tao Hong Si Wu Tang, Dan Shen Yin, Hunag Lian Wen Dan Tang and Gua Lou Xie Bai Ban Xia Tang). In addition, these results delivered novel understandings of the molecular network mechanisms of IHD phenotype subtypes with PSCS complications, which would be both insightful for IHD precision medicine and the integration of disease and TCM syndrome diagnoses.

The TH2-polarizing function of atopic interleukin 17 receptor B-positive dendritic cells up-regulated by lipopolysaccharide.

BACKGROUND: Recent studies suggest that epithelial cell (EC)-derived cytokines contribute to allergic airway disease exacerbation. OBJECTIVE: To confirm our hypothesis that atopic dendritic cells (DCs) are activated to up-regulate the receptors of cytokines that mainly derived from ECs and enhance TH2 responses. METHODS: The expressions of interleukin 17 receptor B (IL-17RB) (IL-25 receptor), membrane-bound ST2 (IL-33 receptor), thymic stromal lymphopoietin receptor (TSLPR), granulocyte-macrophage colony-stimulating factor receptor (GM-CSFR), and several functional markers on CD1c+ monocyte-derived DCs (mo-DCs) were detected by flow cytometry. Lipopolysaccharide (LPS)-activated mo-DCs were cocultured with autologous CD4+ T cells, and cytokine production by these T cells was determined by intracellular flow cytometry. RESULTS: LPS activated both nonatopic and atopic mo-DCs to express a higher level of GM-CSFR but only activated atopic mo-DCs to express increased IL-17RB, which was subsequently activated by IL-25 involved with signal transducer and activator of transcription 5 phosphorylation. In addition, LPS increased the expression of the OX40 ligand (OX40L) but decreased inducible costimulator ligand on atopic CD86+ mo-DCs. More importantly, IL-25 further up-regulated OX40L on atopic CD86+ mo-DCs. After coculturing with LPS-activated mo-DCs from atopic individuals, CD4+ T cells had enhanced inflammatory responses by increased production of IL-4, IL-5, IL-13, and interferon γ (IFN-γ). In contrast, further addition of IL-25 led CD4+ T cells to produce higher level of IL-4 but lower level of IFN-γ. CONCLUSION: Atopic IL-17RB+ DCs can be up-regulated by LPS and promote a TH2-type response, implying that the IL-25/IL-17RB pathway may represent a potential molecular mechanism underlying the regulation of ECs on DCs in allergic airway disease.

Oncogenic potential of IDH1R132C mutant in cholangiocarcinoma development in mice.

AIM: To investigate whether IDH1R132C mutant in combination with loss of p53 and activated Notch signaling promotes intrahepatic cholangiocarcinoma (ICC) development. METHODS: We applied hydrodynamic injection and sleeping beauty mediated somatic integration to induce loss of p53 (via shP53), activation of Notch [via intracellular domain of Notch1 (NICD)] and/or overexpression of IDH1R132C mutant together with the sleeping beauty transposase into the mouse liver. Specifically, we co-expressed shP53 and NICD (shP53/NICD, n = 4), shP53 and IDH1R132C (shP53/IDH1R132C, n = 3), NICD and IDH1R132C (NICD/IDH1R132C, n = 4), as well as NICD, shP53 and IDH1R132C (NICD/shP53/IDH1R132C, n = 9) in mice. Mice were monitored for liver tumor development and euthanized at various time points. Liver histology was analyzed by hematoxylin and eosin staining. Molecular features of NICD/shP53/IDH1R132C ICC tumor cells were characterized by Myc tag, Flag tag, Ki-67, p-Erk and p-AKT immunohistochemical staining. Desmoplastic reaction in tumor tissues was studied by Picro-Sirius red staining. RESULTS: We found that co-expression of shP53/NICD, shP53/IDH1R132C or NICD/IDH1R132C did not lead to liver tumor formation. In striking contrast, co-expression of NICD/shP53/IDH1R132C resulted in ICC development in mice (P < 0.01). The tumors could be identified as early as 12 wk post hydrodynamic injection. Tumors rapidly progressed, and by 18 wk post hydrodynamic injection, multiple cystic lesions could be identified on the liver surface. NICD/shP53/IDH1R132C liver tumors shared multiple histological features of human ICCs, including hyperplasia of irregular glands. Importantly, all tumor cells were positive for the biliary epithelial cell marker cytokeratin 19. Extensive collagen fibers could be visualized in tumor tissues using Sirus red staining, duplicating the desmoplastic reaction observed in human ICC. Tumors were highly proliferative and expressed ectopically injected genes. Together these studies supported that NICD/shP53/IDH1R132C liver tumors were indeed ICCs. Finally, no p-AKT or p-ERK positive staining was observed, suggesting that NICD/shP53/IDH1R132C driven ICC development was independent of AKT/mTOR and Ras/MAPK signaling cascades. CONCLUSION: We have generated a simple, non-germline murine ICC model with activated Notch, loss of p53 and IDH1R132C mutant. The study supported the oncogenic potential of IDH1R132C.

[Study on Macrocosmic Diagnostic Criteria for Coronary Heart Disease with Intermingled Phlegm- Blood Stasis Syndrome].

Macrocosmic diagnostic criteria for coronary heart disease (CHD) with phlegm-damp- ness syndrome (PDS) were established after screening based on macrocosmic indices of CHD with PDS after previous literature analyses and experts consultations. The weights of macrocosmic indices of PDS were compared using analytic hierarchy process (AHP). Macrocosmic diagnostic criteria for CHD with intermingled phlegmblood stasis syndrome were studied by combining with diagnostic criteria for CHD patients with blood stasis syndrome (BSS) set by Academician CHEN Ke-ji group.

Mesenteric lymph duct ligation after hemorrhagic shock enhances the ATP level and ATPase activity in rat kidneys.

BACKGROUND: Kidney injury commonly occurs following hemorrhagic shock. This study aims to observe the effects of mesenteric lymph duct ligation (MLDL) on the adenosine triphosphate (ATP) levels and the cell membrane adenosine triphosphatase (ATPase) activity in the kidneys of rats subjected to hemorrhagic shock. METHODS: Wistar rats were assigned into sham, shock, and ligation groups. The hemorrhagic shock model was established in the shock and ligation groups, and MLDL was performed in the ligation group after resuscitation. Renal homogenates were prepared to determine the ATP and ATPase levels at 90 min after hemorrhage and at 0, 1, 3, 6, 12, and 24 h after resuscitation. RESULTS: The ATP levels, and the Na(+)-K(+)-ATPase, Mg(2+)-ATPase, Ca(2+)-ATPase, and Ca(2+)-Mg(2+)-ATPase activities in the renal tissue of the shock group were lower than those in the sham group at the multiple time points. Furthermore, the corresponding values in the ligation group were significantly higher than those in the shock group at multiple time points. CONCLUSION: MLDL improves energy metabolism and enhances the ATPase activity in the kidneys of hemorrhagic shock rats, along with other mechanisms that alleviate renal injury after hemorrhagic shock.

[Expression and purification of heptad repeat region of the mumps virus F protein and analysis of characteristics].

Two Heptad repeat motifs (HR1 and HR2) from paramyxoviruses F protein could form thermostable heterodimers containing high alpha-helix while virus infected host cell. Following that the viral membrane and the host cell membrane were juxtaposed, which leads to membrane fusion. Mumps virus (MuV) is a member of the genus Rubulavirus in the family of Paramyxoviridae. MuV could use similar infection mechanism as well as other paramyxoviruses. In this study the HR1 and HR2 regions of MuV F protein were predicted by a computer program and expressed in E. coli with the GST fusion expression system. The GST fusion or GST-removed proteins were purified with Gluthathion Sepharose 4B Column. GST pull-down experiment suggested the interaction of HR1 and HR2 peptides, and analysis of gel filtration showed two peptides could form multimer, which indicates that the HR regions of MuV F protein may play an important role in virus fusion.