Down-regulation of the Smad signaling by circZBTB46 via the Smad2-PDLIM5 axis to inhibit type I collagen expression / 老年心脏病学杂志（英文版）

BACKGROUND@#Abnormal type I collagen (COL1) expression is associated with the development of many cardiovascular diseases. The TGF-beta/Smad signaling pathway and circRNAs have been shown to regulate COL1 gene expression, but the underlying molecular mechanisms are still not fully understood.@*METHODS@#Gain- and loss-of-function experiments were prformed to study the effect of circZBTB46 on the expression of alpha 2 chain of type I collagen (COL1A2). Co-immunoprecipitation assay was performed to observe the interaction between two proteins. RNA immunoprecipitation assay and biotin pull-down assay were performed to observe the interaction of circZBTB46 with PDLIM5.@*RESULTS@#In this study, we investigated the role of circZBTB46 in regulating COL1A2 expression in human vascular smooth muscle cells (VSMCs). We found that circZBTB46 is expressed in VSMCs and that TGF-beta inhibits circZBTB46 formation by downregulating KLF4 expression through activation of the Smad signaling pathway. CircZBTB46 inhibits the expression of COL1A2 induced by TGF-beta. Mechanistically, circZBTB46 mediates the interaction between Smad2 and PDLIM5, resulting in the inhibition of Smad signaling and the subsequent downregulation of COL1A2 expression. Furthermore, we found that the expression of TGF-beta and COL1A2 is decreased, while circZBTB46 expression is increased in human abdominal aortic aneurysm tissues, indicating that circZBTB46-mediated regulation of TGF-beta/Smad signaling and COL1A2 synthesis in VSMCs plays a crucial role in vascular homeostasis and aneurysm development.@*CONCLUSIONS@#CircZBTB46 was identified as a novel inhibitor of COL1 synthesis in VSMCs, highlighting the importance of circZBTB46 and PDLIM5 in regulating TGF-beta/Smad signaling and COL1A2 expression.

Host metabolism dysregulation and cell tropism identification in human airway and alveolar organoids upon SARS-CoV-2 infection

The coronavirus disease 2019 (COVID-19) pandemic is caused by infection with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is spread primary via respiratory droplets and infects the lungs. Currently widely used cell lines and animals are unable to accurately mimic human physiological conditions because of the abnormal status of cell lines (transformed or cancer cells) and species differences between animals and humans. Organoids are stem cell-derived self-organized three-dimensional culture in vitro and model the physiological conditions of natural organs. Here we showed that SARS-CoV-2 infected and extensively replicated in human embryonic stem cells (hESCs)-derived lung organoids, including airway and alveolar organoids which covered the complete infection and spread route for SARS-CoV-2 within lungs. The infected cells were ciliated, club, and alveolar type 2 (AT2) cells, which were sequentially located from the proximal to the distal airway and terminal alveoli, respectively. Additionally, RNA-seq revealed early cell response to virus infection including an unexpected downregulation of the metabolic processes, especially lipid metabolism, in addition to the well-known upregulation of immune response. Further, Remdesivir and a human neutralizing antibody potently inhibited SARS-CoV-2 replication in lung organoids. Therefore, human lung organoids can serve as a pathophysiological model to investigate the underlying mechanism of SARS-CoV-2 infection and to discover and test therapeutic drugs for COVID-19.

Identification of Salviae Yunnanensis Radix et Rhizoma and Its Allied Species Based on Chemical Composition by FTIR with Chemometric Analysis and HPLC Fingerprint / 中国实验方剂学杂志

Objective:To investigate the differences of chemical constituents of Salviae Yunnanensis Radix et Rhizoma and its closely related species,and to provide reference for the clinical application of Salviae Yunnanensis Radix et Rhizoma. Method:Fourier transform infrared (FTIR) spectroscopy combined with principal component analysis (PCA),cluster analysis (HCA) and partial least squares discriminant analysis (PLS-DA) were used to study the differences of components between Salviae Yunnanensis Radix et Rhizoma and its closely related species,and high performance liquid chromatography (HPLC) was used to compare the differences of water-soluble components between them. Result:There were some differences between Salviae Yunnanensis Radix et Rhizoma and its closely related species acrcording to FTIR spectroscopy and HPLC fingerprint,especially the water-soluble polar components were more abundant in Salviae Yunnanensis Radix et Rhizoma than other species. The chemical components of Salvia trijuga,S. przewalskii and S. bulleyana were more similar in terms of their genetic relationship. The result showed that the Salviae Yunnanensis Radix et Rhizoma and its closely related species can be clearly distinguished by FTIR combined with chemometrics method. Conclusion:Compared with its closely related species,Salviae Yunnanensis Radix et Rhizoma has a unique chemical composition,which has great therapeutic potential for blood stasis. The FTIR combined with chemometrics model can be used for rapid identification of Salviae Yunnanensis Radix et Rhizoma and its closely related species.

Investigation of Skin Irritation of Essential Oils from Interior-warming Medicines / 中国实验方剂学杂志

Objective:To investigate the skin irritation of essential oils(EOs) extracted from interior-warming medicines. Method:Three EOs from interior-warming medicines(Cinnamomi Cortex, Caryophylli Flos and Alpiniae Officinarum Rhizoma) were selected as research objects.The in vitro skin cytotoxicity and in vivo skin irritation of these EOs were determined and compared.Moreover, the skin irritation was also predicted by the novel skin test panels. Result:Toxicity of these three EOs to human skin fibroblasts(HSF) was significantly different, half-inhibitory concentration(IC50) values of EOs from Cinnamomi Cortex, Alpiniae Officinarum Rhizoma and Caryophylli Flos were (11.16±0.28), (53.33±1.71), (226.70±17.61) mg·L-1, respectively.However, in vivo skin irritation evaluation showed that the local toxicity of these three EOs was in the order of EO of Cinnamomi Cortex > EO of Caryophylli Flos > EO of Alpiniae Officinarum Rhizoma. The evaluation results of skin test panels for these three EOs were in accordance with the results of in vivo skin irritation evaluation. Conclusion:Toxicity of these three EOs against skin cells in vitro is inconsistent with their in vivo skin irritation. Skin test panels are expected to be able to accurately predict in vivo skin irritation of EOs instead of cytotoxicity evaluation.

Comparison of Polyphyllins Content in Paris Polyphylla Planted under Walnut Forest in Different Areas of Yunnan Yangbi / 中国药师

Objective:To compare 4 polyphyllins contents in Paris polyphylla planted under walnut forest in different areas of Yun-nan Yangbi. Methods:Paris polyphylla samples planted under walnut forest were collected in different areas of Yunnan Yangbi, and according to the methods described in Chinese Pharmacopoeia (2015 edition), the contents were determined. Results:Yunnan Yangbi different planted in Paris polyphylla four polyphyllins content of each sample there were significant differences between samples were cultivated in imitation of the wild forest, but the cultivation of varying lengths of time, the growth period of 4 to 5 years in Paris polyphylla four polyphyllins content was significantly higher than that of 3 born in Paris polyphylla. Conclusion: Four kinds of Paris polyphylla saponin content of the samples have significant differences with the Paris polyphylla growth of ecological environment, growth period and the same species living on different populations, the genetic background.

Mapping of the B Cell Neutralizing Epitopes on ED III of Envelope Protein from Dengue Virus / 病毒学报

Dengue virus (DENV) envelope [E] protein is the major surface protein of the virions that indued neutralizing antibodies. The domain III of envelope protein (EDIII) is an immunogenic region that holds potential for the development of vaccines; however, the epitopes of DENV EDIII, especially neutralizing B-cell linear epitopes, have not been comprehensively mapped. We mapped neutralizing B-cell linear epitopes on DENV-1 EDIII using 27 monoclonal antibodies against DENV-1 EDIII proteins from mice immunized with the DENV-1 EDIII. Epitope recognition analysis was performed using two set of sequential overlapping peptides (16m and 12m) that spanned the entire EDIII protein from DENV-1, respectively. This strategy identified a DENV-1 type- specific and a group-specific neutralizing epitope, which were highly conserved among isolates of DENV-1 and the four DENV serotypes and located at two regions from DENV-1 E, namely amino acid residues 309-320 and 381-392(aa 309-320 and 381-392), respectively. aa310 -319(310KEVAETQHGT319)was similar among the four DENV serotypes and contact residues on aa 309 -320 from E protein were defined and found that substitution of residues E309 , V312, A313 and V320 in DENV-2, -3, -4 isolates were antigenically silent. We also identified a DENV-1 type-specific strain-restricted neutralizing epitope, which was located at the region from DENV-1 E, namely amino acid residues 329-348 . These novel type- and group-specific B-cell epitopes of DENV EDIII may aid help us elucidate the dengue pathogenesis and accelerate vaccine design.

Expression and identification of the functional domains of dengue virus type 1 envelope protein in 293T cells / 中华微生物学和免疫学杂志

Objective To construct a recombinant expression vector for expression of the function-al domains of dengue virus serotype 1 ( DENV1 ) envelope ( E ) protein in native soluble form. Methods The genes encoding the functional domains of DENV1-E protein (1-394 aa) were amplified with PCR and then cloned into the Psectag2B-Fc eukaryotic expression vector.The 293T cells were transfected with the recombinant vector by cationic lipid-based delivery.The cell clones expressing the fusion DENV1-E-Fc protein were screened out with 2 mg/ml of Zeocin.Immunofluorescence assay ( IFA) was performed to analyze the antigenicity and integrity of the fusion protein.The fusion proteins were purified from cell lysate with Protein-G and further identified by Western blot assay.Results The soluble form of fusion protein with a molecular weight of about 90×103 was obtained at a yield of about 25 μg per 1×107 cells.The results of IFA indicated that the fusion protein kept its integrity with right conformational epitopes.The fusion protein was successfully expressed with the advantage of good specificity as indicated by IFA and Western blot assay. Conclusion The recombinant fusion protein in soluble form was successfully expressed in eukaryotic ex-pression system, which paved the way for further investigation on the function of DENV1 E protein and its protective epitopes.

Role of p38 mitogen-activated protein kinase in spinal cord in development of persistent postoperative pain in rats: the relationship with Toll-like receptor 4 / 中华麻醉学杂志

Objective To evaluate the role of p38 mitogen-activated protein kinase (p38MAPK) in the spinal cord in the development of persistent postoperative pain evoked by skin/muscle incision and retraction (SMIR) and the relationship with Toll-like receptor 4 (TLR4).Methods One hundred and twenty male SpragueDawley rats,weighing 200-250 g,aged 2 months,in which intrathecal catheters were successfully implanted,were randomly divided into 5 groups (n =24 each) using a random number table:sham operation group (group S),SMIR group,SMIR + dimethyl sulfoxide (DMSO) group (group DMSO),SMIR + p38MAPK inhibitor SB203580 group (group SB203580) and SMIR + TLR4 small interference RNA (siRNA) group (group TLR4siRNA).The rats were anesthetized with intraperitoneal chloral hydrate 400 mg/kg.The skin and superficial muscle of the medial thigh were incised and a small pair of retractors inserted.This tissue was retracted for 1 h causing potential stretch of the saphenous nerve.2％ DMSO 10 μl and SB203580 5 μg were injected intrathecally at 30 min before operation and 1-12 days after operation in DMSO and SB203580 groups,respectively.TLR4siRNA 2 μg was administered intrathecally at 1 day before operation and 1-12 days after operation once a day in group TLR4siRNA.Mechanical paw withdrawal threshold to von Frey filament stimulation (MWT) was measured at 1 day before operation and 1,3,7,12 and 22 days after operation.Four rats in each group were sacrificed after measurement of MWT at each time point,and the L4-6 segments of the spinal cord were obtained for detection of the expression of phosphorylated p38MAPK (p-p38MAPK) by Western blot analysis.Results Compared with group S,MWT was significantly decreased after operation,and the expression of p-p38MAPK was up-regulated after operation in SMIR and DMSO groups.Compared with group SMIR,MWT was significantly increased after operation,and the expression of p-p38MAPK was down-regulated after operation in SB203580 and TLR4siRNA groups,and no significant changes in MWT and p-p38MAPK expression were found at each time point in group DMSO.Conclusion TLR4-triggered activation of p38MAPK in spinal cord is involved in the development of SMIR-evoked persistent postoperative pain in rats.

Role of Toll-like receptor 4 in spinal cord in a rat model of persistent postoperative pain evoked by skin/ muscle incision and retraction / 中华麻醉学杂志

Objective To investigate the role of Toll-like receptor4 (TLR4) activation in spinal cord in a rat model of persistent postoperative pain evoked by skin/muscle incision and retraction(SMIR).Methods Ninetysix male SD rats weighing 200-250 g were randomly divided into 4 groups(n =24 each):group sham operation; group SMIR; group SMIR + IT scramble siRNA and group SMIR + IT TLR4siRNA.The rat model of persistent postoperative pain evoked by SMIR was established according to the method described by Flatters.The TLR4 siRNA were administered intrathecally for 7 days starting from 1 day beforc surgcry.Pain behavior was assessed by paw mechanical withdraw threshold (MWT) to Electronic von Frey Anesthesiometer stimulation at 1 day before and 1,3,7,12,and 22 days after operation.Four animals were sacrificed at each time point in each group for detection of the expression of TLR4 protein in the spinal cord by Western blot analysis.Results Compared to group sham group,MWT was significantly descreased at 3,7,12,and 22 days after operation,while the expression of TLR4 protein in the spinal cord were significantly increased at 3,7,12 days after operation in group SMIR and group SMIR + IT scramble siRNA ; IT TLR4siRNA significantly attenuated the hyperalgesia induced by SMIR and descreased the expression of TLR4 protein at 3,7,12 days after operation in group SMIR + IT TLR4siRNA.Conclusion TLR4 activation in spinal cord plays an important role in the development of SMIR-evoked persistent postoperative pain in rats.

Gene polymorphism of CYP450 2C9 and VKORC1 in Chinese population and their relationships to the maintaining dosage of warfarin / 中华流行病学杂志

Objective To investigate the distribution of gene polymorphism of CYP450 2C9 and VKORC1-1639A/G in the Chinese population as well as the difference of genetic polymorphism between Chinese Han population and other ethnic populations.Contribution of CYP2C9 and VKORC1 genotype to the maintenance doses on warfarin was also studied.Methods The genotype and allele frequencies were calculated and compared with those in other populations.One hundred and one patients with stable anticoagulation with warfarin under a target international normalized ratio(INR)of 2.0 to 3.0 were enrolled for studying the relationship between the CYP2C9 and VKORC1 gene polymorphism and the warfarin maintaining dosage.Results CYP450 2C9~*3 + 1075C/A allele frequencies were:AA in 449 cases(92.2%),AC in 36 cases(7.4%)and CC in 2 cases(0.4%),respectively.VKORC1-1639A/G allele frequencies were AA in 415 cases(85.2%),GA in 72 cases(14.8%),but GG in no case(0.0%),respectively.When linear stepwise regression analysis was used to identify factors contributing to warfarin stable dose,the final equation was:ln(D)=0.346 + 0.017(weight)-0.376(CYP450 2C9~*3 + 1075C/A)+ 0.148(VKORC1-1639A/G)-0.002(age)(r=0.827,P=0.02).Conclusion There existed significant gene polymorphism CYP450 2C9~*3 + 1075C/A and VKORC1-1639A/G in the Chinese Han population.Both Gene polymorphisms of CYP450 2C9*3 + 1075C/A and VKORC1-1639A/G were significantly affecting the maintaining dose of warfarin in the Chinese population.

To evaluate the neutralizing abilities of anti-dengue virus antibodies with nonstructural protein 1 antigen capture enzyme-linked immunosorbent assay / 中华预防医学杂志

<p><b>OBJECTIVE</b>To produce neutralizing antibodies against envelope protein domain III (EDIII) of dengue virus serotype I (DENV-1) and evaluate the nonstructural protein 1 (NS1) antigen capture enzyme-linked immunosorbent assay (ELISA) for identification of antibody neutralizing abilities.</p><p><b>METHODS</b>Five BALB/c mice and one New Zealand Rabbit were immunized with recombinant EDIII protein of DENV-1 for the production of hybridomas and hyperimmune sera. Indirect ELISA, immunofluorescence assay (IFA) and Western Blot analyses were applied to identify specificity of antibodies. Comparing to plaque reduction neutralization test (PRNT), the new established DENV-1 specific NS1 antigen capture ELISA was used for detecting the neutralizing abilities of these antibody.</p><p><b>RESULTS</b>Four strains of monoclonal antibodies (mAbs) named 1A1, 1B3, 3D3 and 9D6 and one hyperimmune serum of rabbit were obtained, all of which were approved to have neutralizing abilities to DENV-1 with the PRNT titer of 1:1024, 1:512, 1:256, 1:4096 and 1:4096. MAb 3D3 with the lowest neutralization titer in PRNT had not shown neutralizing ability to DENV-1 in NS1 antigen capture ELISA, while MAbs 1A1, 1B3 and 9D6 and the rabbit hyperimmune serum could protect the C6/36 from being infected by DENV-1 with the neutralization titer of 1:32, 1:32, 1:128 and 1:128 in this assay.</p><p><b>CONCLUSION</b>NS1 antigen capture ELISA could be used to identify antibody neutralizing abilities to DENV, it was a faster and more convenient way to screen antibodies with high neutralization titer and might also be used as one of the methods to evaluate the effects of vaccines.</p>

Inulicin inhibits activation and expression of vascular remodeling enzymes induced by de-endothelium / 中国应用生理学杂志

<p><b>AIM</b>To observe the effects of inulicin on the neointimal hyperplasia and expression of matrix metalloproteinase-2 (MMP-2) and tissue inhibitor of metalloproteinase-2 (TIMP-2) after balloon injury in rat aorta.</p><p><b>METHODS</b>The intimal hyperplasia model was replicated by balloon injury. The histological changes in vascular wall were observed by HE staining. MMP-2 activation was tested by gelatin zymogram analysis; MMP-2 and TIMP-2 expression was detected by Western blot and immunohistochemistry analysis.</p><p><b>RESULTS</b>Neointimal hyperplasia induced by balloon injury was significantly inhibited by inulicin. The proteolytic activity and the expression of MMP-2 and ratio of MMP-2 and TIMP-2 were also returned to control level by inulicin after balloon injury.</p><p><b>CONCLUSION</b>Inulicin inhibits hyperplasia of neointima by modulating the balance of MMP-2 and TIMP-2.</p>

Expression of osteopontin RGD peptide in E. coli and its biological activities / 中国应用生理学杂志

<p><b>AIM</b>The six copies of RGD sequences present in osteopontin were expressed in the E. coli, and the biological activity of the purified products was studied.</p><p><b>METHODS</b>cDNA fragments containing six copies of RGD sequences were subcloned into prokaryotic expression vector pGEX-3X including GST coding sequence to construct pGEX-3X-RGD plasmids. E. coli DH5alpha transformed by pGEX-3X-RGD(6) plasmid was induced by different IPTG concentrations for different times to identify the optimal induction condition. Induced GST-RGD fusion protein was purified via GST-Sepharose 4B affinity resin.</p><p><b>RESULTS</b>GST-RGD fusion proteins containing six copies of RGD sequences could be successfully induced and were mainly located in inclusion bodies. After being denatured and dialyzed, renatured fusion proteins were purified via GST-Sepharose 4B affinity resin. GST-RGD(6) fusion protein could specifically inhibit adhesion and migration of VSMC stimulated by osteopontin, which could be considered as a basis on producing small peptides containing RGD sequences for inhibition of VSMC adhesion and migration.</p><p><b>CONCLUSION</b>The six copies of osteopontin RGD peptide were successfully expressed in E. coli DH5alpha. The purified GST-RGD fusion protein could inhibit the adhesion and migration of VSMC stimulated by osteopontin.</p>

The molecular mechanisms of SM22alpha in cytoskeleton remodeling of vascular smooth muscle cells / 中国应用生理学杂志

<p><b>AIM</b>To investigate the molecular mechanisms of smooth muscle 22 alpha (SM22alpha) whereby cytoskeleton remodeling of vascular smooth muscle cells (VSMCs) is regulated.</p><p><b>METHODS</b>Synthetic (dedifferentiated) VSMCs were converted to contractile (differentiated) VSMCs by serum deprivation. Cells were transfected with pEGFP-SM22alpha, and localization of SM22alpha and its relationship with F-actin were observed through fluorescence microscopy. Fractional extraction of proteins and Western blotting were used to detect polymerization of SM alpha-actin in antisense-pcD2-SM22alpha-transfected VSMCs.Furthermore, effect of SM22alpha on F-actin cross-linking was observed by F-actin polymerization experiment.</p><p><b>RESULTS</b>Fluorescence microscopy showed that SM22alpha co-localized with F-actin in contractile VSMCs. Western blotting of protein extracts from F-/G-actin fractions revealed that polymerization of SM alpha-actin was lower in antisense-pcD2-SM22alpha-transfected VSMCs, in which SM alpha-actin mostly existed as soluble G-actin. Moreover, F-actin polymerization in vitro also showed that GST-SM22alpha could promote cross-linking of F-actin to form thick and bundled stress fibres,while extracts from VSMCs transfected with antisense-pcD2-SM22alpha could not effectively induce the polymerization of F-actin.</p><p><b>CONCLUSION</b>SM22alpha acts as a modulator to participate in VSMC cytoskeleton remodeling. It can not only induce polymerization of G-actin to F-actin, but also promote cross-linking of F-actin to bundled stress fibres, indicating its vital role in cytoskeleton remodeling.</p>

Experimental study on inhibition of restenosis by osteopontin oligopeptide antagonist after de-endothelium / 中国应用生理学杂志

<p><b>AIM</b>Osteopontin 13-peptide(Gly158-Lys170), containing multi-function domains was used to inhibit the VSMC adhesion, migration. The mechanism of 13-peptide inhibiting neointima formation was investigated.</p><p><b>METHODS</b>The effect of 13-peptide on VSMC adhesion was tested by adhesion assay. The restenosis model was prepared balloon injury after administration of 13-peptide for 1 h, and then the 13-peptide was given by an intravenous drip for 7 days. The expression changes of OPN, FAK, ILK in vessel wall were detected by immunohistochemistry and Western blot.</p><p><b>RESULTS</b>The 13-peptide dose-dependently reduced adhesion of VSMC in OPN matrix, and the infiltration of macrophage in vessel wall also was reduced in the treatment group after balloon injury. The expression of OPN, FAK, ILK was down-regulated following with the inhibition of neointima thickening.</p><p><b>CONCLUSION</b>The OPN 13-peptide can inhibit inflammation and neointima formation by blocking the binding of OPN to it's receptors.</p>

Expression and identification of H5 subtype hemagglutinin of avian influenza A virus in insect cells / 南方医科大学学报

<p><b>OBJECTIVE</b>To clone and express avian influenza A virus [A/Hong Kong/482/97(H5N1)] H5 subtype hemagglutinin in baculovirus-insect cell expression system and investigate the antigenicity and bioactivity of the recombinant protein.</p><p><b>METHODS</b>H5 gene of influenza A virus was amplified by PCR. The recombinant bacmid was obtained by cloning the gene to the donor plasmid of pFastBacHTB and transformed into DH10Bac competent cells. The recombinant baculovirus stock was prepared by transfecting the recombinant bacmid DNA into the insect cell line for protein expression after amplification. Immunofluorescene assay (IFA) and Western blotting were performed to identify the antigenicity of the recombinant protein, and hemagglutination assay was used to identify its bioactivity.</p><p><b>RESULTS</b>The recombinant his-H5 protein was expressed in the insect cells with a relative molecular mass of 64,000, which showed erythrocyte-agglutinating activities with the red blood cells of guinea pig. Western blotting and IFA demonstrated that the recombinant his-H5 could be recognized and bound by standard anti-H5 sera.</p><p><b>CONCLUSION</b>The recombinant his-H5 with a post-translation modification is successfully obtained in insect cells, which may provide a potential source for further study of the antigen's biological function and for production of the subunit vaccine or monoclonal antibodies.</p>

Recombinant C-terminal fragment of SM22 induces cytoskeleton reorganization / 中国应用生理学杂志

<p><b>AIM</b>To investigate the interaction between C-terminal domains of SM22alpha and cytoskeleton F-actin.</p><p><b>METHODS</b>Prokaryotic expression vector containing SM22alpha cDNA and GST sequence was constructed. The induction conditions were optimized to increase the product of soluble GST-SM22alpha fusion protein in E coli. Expression products were purified and rabbit anti-GST-SM22alpha polyclonal antibody was produced by the purified fusion protein. In order to explore the effect of SM22alpha on cytoskeleton reorganization, VSMCs were treated with serum withdrawal and then serum stimulation to induce contractile/synthetic phenotypic modulation. SM22alpha protein distribution in F-actin/G-actin fractions was detected by Western blotting. The interaction between SM22alpha and actin was examined by GST pull down assay and coimmunoprecipitation. Colocalization of endogenous SM22alpha with F-actin was observed by immunofluorescence.</p><p><b>RESULTS</b>The results showed that the expression of soluble GST-SM22alpha protein was the highest under condition induced by 30 degrees C, 0.5 mmol/L IPTG for 6 h. Immunofluorescence and Western blotting of protein extracts from F-actin/G-actin fractions revealed that SM22alpha colocalized with F-actin during VSMC redifferentiation. GST pull down assay and coimmunoprecipitation showed that SM22alpha interacted with F-actin by C-terminal domains to participate in cytoskeleton reorganization.</p><p><b>CONCLUSION</b>The recombinant SM22alpha C-terminal domains have the ability to bind F-actin, by which SM22alpha interacts with actin and participates in cytoskeleton reorganization.</p>

Expression, purification and antibody preparation of recombinant human SM22alpha / 中国应用生理学杂志

<p><b>AIM</b>The recombinant human smooth muscle 22 alpha (SM22alpha) was expressed by using Pichia pastoris.</p><p><b>METHODS</b>Using pGEM3z-SM22alpha as the template, SM22alpha coding region was amplified by PCR, and was inserted the expression vector pPIC9. Then the recombinant plasmid pPIC9-SM22alpha was transfected into Pichia pastoris. The products induced by methanol were precipitated by ammonium sulfate, then CM-cellulose chromatography was performed for SM22alpha. Polyclonal antibody against SM22alpha was produced by immunizing a rabbit with purified recombinant SM22alpha.</p><p><b>RESULTS</b>The positive clone with SM22alpha got high output at 84 hours after induction by methanol. The SM22alpha prepared by ammonium sulfate fractionation and chromatographic separation showed a single band whose apparent molecular weight was 22 kD on SDS-PAGE. Polyclonal antibody against SM22alpha could detect the SM22alpha expression in human or rat vascular walls.</p><p><b>CONCLUSION</b>High-level expression of SM22alpha is successfully achieved in Pichia pastoris. Antibody against SM22alpha can be used to explore the function of SM22alpha.</p>

Antigenicity analysis of nucleocapsid proteins of 3 human coronaviruses SARS-CoV, 229E and OC43 with their monoclonal antibodies / 南方医科大学学报

<p><b>OBJECTIVE</b>To prepare and characterize monoclonal antibodies (mAbs) against the recombinant nucleocapsid (N) protein of 3 human coronaviruses SARS-CoV, 229E and OC43 and study the antigenic relationship between the 3 N proteins.</p><p><b>METHODS</b>BALB/c mice were immunized with the recombinant N proteins of SARS-CoV, 229E and OC43 to obtain the mAbs by means of hybridoma. Screening and identification of the mAbs were performed using indirect enzyme-linked immunosorbent assay (ELISA), Western blotting and indirect immunofluorescence assay. Cross-reactivity between the N proteins of the 3 coronaviruses was analyzed with the prepared mAbs.</p><p><b>RESULTS</b>The mAbs against the recombinant N proteins of SARS-CoV, 229E and OC43 were obtained, which reacted specifically with the corresponding viral N protein as shown by indirect ELISA, Western blotting and indirect immunofluorescence assay. No cross-reactivity was found between the 3 N proteins.</p><p><b>CONCLUSION</b>The prepared mAbs against the recombinant N proteins may provide valuable assistance in studying antigenic relationships of N proteins between the 3 human coronaviruses.</p>

Development and application of triple antibodies-based sandwich ELISA for detecting nucleocapsid protein of SARS-associated coronavirus / 中华流行病学杂志

<p><b>OBJECTIVE</b>To prepare and characterize monoclonal antibodies (mAb) and polyclonal antibodies against nucleocapsid (N) protein of severe acute respiratory syndrome (SARS)-associated coronavirus (SARS-CoV) and to establish antibodies-based sandwich ELISA for detecting N protein of SARS-CoV, which might apply to early diagnosis of patients with SARS-CoV infection.</p><p><b>METHODS</b>BALB/c mice were immunized with purified recombinant N protein of SARS-CoV for producing mAbs, and New Zealand white rabbits were immunized for producing polyclonal antibodies. The identification of antibodies was performed using indirect enzyme-linked immunosorbent assay (ELISA), indirect fluorescent-antibody assay (IFA), and Western immunoblotting. Capturing and detecting antibodies were selected by pairing the mAbs and polyclonal antibodies one by one and an antibodies-based sandwich antigen capture ELISA was used for detecting N antigen of SARS-CoV.</p><p><b>RESULTS</b>Nine mAbs and hyperimmune rabbit polyclonal antibodies, specifically against SARS-CoV nucleocapsid protein were obtained. Using paired ELISA assay, three mAbs N1E8, N8E1 and N10E4 were selected as capturing antibody and rabbit polyclonal antibodies as detecting antibody then triple antibodies-based sandwich ELISA was established following horseradish peroxidase (HRP)-conjugated goat anti-rabbit immunoglobulin G. The recombinant N protein was used as a standard to establish a detection sensitivity of approximated 50 pg/ml with this assay. When tested with 420 serum specimens from serologically confirmed SARS patients, the positive rates of serum N protein were 90.1%, 23% and 0%, in which sera collected from 1 to 10 days, 11 to 20 days and beyond 21 days respectively after the onset of symptoms. The specificity of the assay was 99.86% in 715 control serum specimens. There was no cross-reaction with other respiratory viruses and coronaviruses.</p><p><b>CONCLUSION</b>Specific and high affinity mAbs and rabbit polyclonal antibodies were obtained. By paired and optimized sandwich ELISA, a sensitive and specific antigen capture ELISA was established for detecting N antigen of SARS-CoV, which might apply to early diagnosis, source tracing and epidemiological studies of SARS.</p>