Magnetic resonance imaging(MRI)is a powerful tool for diagnosing and monitoring brain diseases,but its low sensitivity can hinder early detection.To address this challenge,we utilized chemical exchange saturation tran...Magnetic resonance imaging(MRI)is a powerful tool for diagnosing and monitoring brain diseases,but its low sensitivity can hinder early detection.To address this challenge,we utilized chemical exchange saturation transfer(CEST)MRI,which greatly enhances sensitivity for detecting low-concentration compounds.In this study,we developed a CEST contrast agent based on a recombinant adeno-associated viruses(rAAVs)encoding the protamine-1(PRM1)MRI reporter gene.CEST MRI revealed that PRM1 contrast agent effectively highlighted caudate putamen region after injection of the rAAVs into the mouse brain,clearly distinguishing it from the surrounding tissue,with no observable damage.This method provides a sensitive,metal-free CEST contrast agent for in vivo brain cell detection,demonstrating potential for both diagnostic and therapeutic applications in brain diseases.展开更多
Postoperative cognitive dysfunction is a seve re complication of the central nervous system that occurs after anesthesia and surgery,and has received attention for its high incidence and effect on the quality of life ...Postoperative cognitive dysfunction is a seve re complication of the central nervous system that occurs after anesthesia and surgery,and has received attention for its high incidence and effect on the quality of life of patients.To date,there are no viable treatment options for postoperative cognitive dysfunction.The identification of postoperative cognitive dysfunction hub genes could provide new research directions and therapeutic targets for future research.To identify the signaling mechanisms contributing to postoperative cognitive dysfunction,we first conducted Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses of the Gene Expression Omnibus GSE95426 dataset,which consists of mRNAs and long non-coding RNAs differentially expressed in mouse hippocampus3 days after tibial fracture.The dataset was enriched in genes associated with the biological process"regulation of immune cells,"of which Chill was identified as a hub gene.Therefore,we investigated the contribution of chitinase-3-like protein 1 protein expression changes to postoperative cognitive dysfunction in the mouse model of tibial fractu re surgery.Mice were intraperitoneally injected with vehicle or recombinant chitinase-3-like protein 124 hours post-surgery,and the injection groups were compared with untreated control mice for learning and memory capacities using the Y-maze and fear conditioning tests.In addition,protein expression levels of proinflammatory factors(interleukin-1βand inducible nitric oxide synthase),M2-type macrophage markers(CD206 and arginase-1),and cognition-related proteins(brain-derived neurotropic factor and phosphorylated NMDA receptor subunit NR2B)were measured in hippocampus by western blotting.Treatment with recombinant chitinase-3-like protein 1 prevented surgery-induced cognitive impairment,downregulated interleukin-1βand nducible nitric oxide synthase expression,and upregulated CD206,arginase-1,pNR2B,and brain-derived neurotropic factor expression compared with vehicle treatment.Intraperitoneal administration of the specific ERK inhibitor PD98059 diminished the effects of recombinant chitinase-3-like protein 1.Collectively,our findings suggest that recombinant chitinase-3-like protein 1 ameliorates surgery-induced cognitive decline by attenuating neuroinflammation via M2 microglial polarization in the hippocampus.Therefore,recombinant chitinase-3-like protein1 may have therapeutic potential fo r postoperative cognitive dysfunction.展开更多
Objective To construct the recombinant adenovirus vector carrying human growth hormone secretagogue receptor type 1a （GHS-R1a） ,for genetic transfection.Methods The full-length human GHS-R1a gene was obtained by PCR...Objective To construct the recombinant adenovirus vector carrying human growth hormone secretagogue receptor type 1a （GHS-R1a） ,for genetic transfection.Methods The full-length human GHS-R1a gene was obtained by PCR amplification and then cloned into the shuttle plasmid pAdTrack-CMV.The linearized plasmid pAdTrack-CMV-GHS-R1a was co-transformed into Escherichia coli （E.coli） BJ5183 cells along with an adenoviral backbone plasmid pAdEasy1.The HEK293 cells were then infected with adenoviruses.The expression of GHS-R1a was indicated by green fluorescent protein （GFP） ,and confirmed by Reverse Transcription Polymerase Chain Reaction （RT-PCR） and Western blot.Results Enzymatic digestion of pAdGHS-R1a yielded a large fragment （approximately 30 kb） and a small fragment （4.5 kb） ,indicating the success-ful construction of recombinant adenovirus expression vector.Expression of GFP was observed by confocal laser scanning microscopy at 24 h after infection.RT-PCR and Western blot further confirmed that GHS-R1a was efficiently expressed in 293 cells.Conclusion Recombinant adenovirus （AdGHS-R1a） is successfully constructed,and the target gene can be expressed efficiently in 293 cells,which provide a valuable tool for further studying the function of GHS-R1a.展开更多
Netrin-1 and its receptors play crucial roles in inducing axonal growth and neuronal migration during neuronal development.Their profound impacts then extend into adulthood to encompass the maintenance of neuronal sur...Netrin-1 and its receptors play crucial roles in inducing axonal growth and neuronal migration during neuronal development.Their profound impacts then extend into adulthood to encompass the maintenance of neuronal survival and synaptic function.Increasing amounts of evidence highlight several key points:(1)Diminished Netrin-1 levels exacerbate pathological progression in animal models of Alzheimer’s disease and Parkinson’s disease,and potentially,similar alterations occur in humans.(2)Genetic mutations of Netrin-1 receptors increase an individuals’susceptibility to neurodegenerative disorders.(3)Therapeutic approaches targeting Netrin-1 and its receptors offer the benefits of enhancing memory and motor function.(4)Netrin-1 and its receptors show genetic and epigenetic alterations in a variety of cancers.These findings provide compelling evidence that Netrin-1 and its receptors are crucial targets in neurodegenerative diseases.Through a comprehensive review of Netrin-1 signaling pathways,our objective is to uncover potential therapeutic avenues for neurodegenerative disorders.展开更多
AIM: To evaluate the effects of positive regulation of recombinant human interleukin 1 receptor antagonist (rhIL-1Ra) on hepatic tissue recovery in acute liver injury in mice induced by carbon tetrachloride (CCl 4 ). ...AIM: To evaluate the effects of positive regulation of recombinant human interleukin 1 receptor antagonist (rhIL-1Ra) on hepatic tissue recovery in acute liver injury in mice induced by carbon tetrachloride (CCl 4 ). METHODS: Acute liver damage was induced by injecting 8-wk-old mice with CCl 4 1 mL/kg (1:3 dilution in corn oil) intraperitoneally (ip). Survival after liver failure was assessed by injecting 8-wk-old mice with a lethal dose of CCl 4 2.6 mL/kg (1:1 dilution in corn oil) ip. Mice were subcutaneously injected with 1 mg/kg recombinant human IL-1Ra twice a day after CCl 4 treatment for 5 d. Serum alanine amino transferase (ALT) and aspartate aminotransferase (AST) levels were determined with a commercial assay kit. Serum IL-1β, IL-1Ra levels were measured by enzyme-linked immunosorbent assay kit. Quantitative real-time polymerase chain reaction was used to determine liver IL-1β, IL-1Ra and IL-6 expression during CCl 4-induced acute liver injury. Liver sections were stained with hematoxylin-eosin. A histology-injury grading system was used to evaluate the degree of necrosis after acute liver injury. Proliferating cell nuclear antigen (PCNA) staining was used to evaluate the role of rhIL-1Ra in promoting hepatocyte proliferation. RESULTS: Quantitative analysis showed a higher level of IL-6 mRNA expression and reduced serum AST and ALT levels in the livers of the rhIL-1Ra-treated group at the early phase of CCl 4-induced acute liver injury. Histological examination indicated a decrease in centrilobular necrotic areas in mice treated with rhIL-1Ra, and a novel role of rhIL-1Ra in promoting hepatocyte proliferation was also supported by an increase of PCNA staining. All these results, accompanied by a strong survival benefit in rhIL-1Ra-treated vs PBS-treated groups, demonstrated that rhIL-1Ra administration ameliorated the histological damage and accelerated the regeneration and recovery process of the liver. CONCLUSION: rhIL-1Ra could be further developed as a novel therapeutic agent for the treatment of acute liver injury because of its ability to reduce hepatocellular damage and facilitate liver regeneration.展开更多
The recombinant Saccharomyces cerevisiae strain stably expressing recombinant human glucagon-like peptide-l（rhGLP-1） analogue, as a potential oral drug delivery system for diabetes type II treatment, was successfull...The recombinant Saccharomyces cerevisiae strain stably expressing recombinant human glucagon-like peptide-l（rhGLP-1） analogue, as a potential oral drug delivery system for diabetes type II treatment, was successfully constructed by the homologous recombination between chromosomal DNA and yeast and integrating vector pNK-GLP containing yeast ribosomal DNA fragments. The amount of rhGLP-I analogue fusion protein in transformant SG2 reached ca. 0.84 mg per gram of packed cells when SG2 was grown for 24 h in the YPD medium with a inoculum and medium ratio of 1：1. Oral administration of 5 g lyophilized SG2/kg to hyperglycemic rats decreased serum glucose from （24.8±1.40） to （21.2±1.36） mmol/L.展开更多
In this study,a standard strain of HSV-1 (strain SM44) was used to investigate the antiviral activity of the recombinant Cyanovirin-N (CV-N) against Herpes simplex virus type 1 (HSV-1) in vitro and in vivo.Cytopathic ...In this study,a standard strain of HSV-1 (strain SM44) was used to investigate the antiviral activity of the recombinant Cyanovirin-N (CV-N) against Herpes simplex virus type 1 (HSV-1) in vitro and in vivo.Cytopathic effect (CPE) and MTT assays were used to evaluate the effect of CV-N on HSV-1 in Vero cells.The number of copies of HSV-DNA was detected by real-time fluorescence quantitative PCR (FQ-PCR).The results showed that CV-N had a low cytotoxicity on Vero cells with a CC50 of 359.03±0.56 μg/mL,and that it could not directly inactivate HSV-1 infectivity.CV-N not only reduced the CPE of HSV-1 when added before or after viral infection,with a 50% inhibitory concentration (IC50) with 2.26 and 30.16μg/mL respectively,but it also decreased the copies of HSV-1 DNA in infected host cells.The encephalitis model for HSV-1 infection was conducted in Kunming mice,and treated with three dosages of CV-N (0.5,5 & 10 mg/kg) which was administered intraperitoneally at 2h,3d,5d,7d post infection.The duration for the appearance of symptoms of encephalitis and the survival days were recorded and brain tissue samples were obtained for pathological examination (HE staining).Compared with the untreated control group,in the 5mg/kg CV-N and 10mg/kg CV-N treated groups,the mice suffered light symptoms and the number of survival days were more than 9d and 14d respectively.HE staining also showed that in 5mg/kg CV-N and 10mg/kg CV-N treated groups,the brain cells did not show visible changes,except for a slight inflammation.Our results demonstrated that CV-N has pronounced antiviral activity against HSV-1 both in vitro and in vivo,and it would be a promising new candidate for anti-HSV therapeutics.展开更多
Objective.To construct recombinant BCG again st leptospirosis.Methods.We amplified the entire open readin g frame of the OmpL1gene from the genome of the leptospire serovar Lai strain 017.Two recombin ant plasmids pBQ...Objective.To construct recombinant BCG again st leptospirosis.Methods.We amplified the entire open readin g frame of the OmpL1gene from the genome of the leptospire serovar Lai strain 017.Two recombin ant plasmids pBQ1and pBQ2were constructed by oriented ligation based on the E.coli-BCG shuttle plasmids pMV261and pMV361respectively.The recombinant plasmids were transformed into BCG by electroporation.The rBCGs bearing pBQ1and pBQ2were induced by high temperature of 45℃.Results.The expressed product,a 35kD prote in was detected by SDS-PAGE.The resu lt indicates that pBQ1and pBQ2can express OmpL1in rBCG.Conclusion.The technical methods in this study may help detect the immunogenicity a nd immunoprotection of OmpL1and develop more safe,highl y effective rBCG bearing leptospira l antigen with long-lasting protection.展开更多
Some unique subclasses of Camelidae antibodies are devoid of the light chain, and the antigen binding site is comprised exclusively of the variable domain of the heavy chain （VHH）. The recombinant VHHs have a high p...Some unique subclasses of Camelidae antibodies are devoid of the light chain, and the antigen binding site is comprised exclusively of the variable domain of the heavy chain （VHH）. The recombinant VHHs have a high potential as alternative reagents for the next generation of immunoassay. In particular, they might be very useful for molecular mimicry. The present study demonstrated an alpaca immunized with the F（ab＇）z fragment of anti-aflatoxin B1 mAb and developed an important anti-idiotypic （anti-ld） responses. Antigen-specific elution method was used for panning private anti-ld VHHs from the constructed alpaca VHH library. The selected VHHs were expressed, renatured, purified, and then identified by a competitive enzyme-linked immunosorbent assay （ELISA）. Our findings indicated that the VHH would be an alternative tool for haptens mimicry studies.展开更多
Objective: To investigate the effect of recombinant human osteoprotegerin combined with tinidazole on mice with periodontitis and the effect on serum RANKL and MCP-1 levels. Methods: 80 SPF-cleaned mice were randomly ...Objective: To investigate the effect of recombinant human osteoprotegerin combined with tinidazole on mice with periodontitis and the effect on serum RANKL and MCP-1 levels. Methods: 80 SPF-cleaned mice were randomly divided into 4 groups, 20 each, model group, tinidazole group and recombinant human osteoprotegerin group were modeled by Kimura et al., and tinidazole group received tinidazole. After intragastric administration, the recombinant human osteoprotegerin group was injected with recombinant human osteoprotegerin in the periodontal pocket according to the tinidazole group. The periodontal changes of the four groups of mice were observed and recorded, and the gingival rating was performed. Epithelial tissue morphology was observed by hematoxylin-eosin (HE) staining. Serum levels of IL-4, IL-6, RANKL and MCP-1 were measured by enzyme-linked immunosorbent assay. Results:After the intervention, the model group developed severe inflammatory reactions, including redness, hemorrhage, and deep periodontal pockets. The teeth were significantly loosened. The mice in the tinidazole group and the recombinant human osteoprotegerin group recovered substantially, and the gingival rating of the recombinant human osteoprotegerin group was better than that. The tinidazole group and the model group (P<0.05). The results of HE staining showed that the model group had edema, vasodilation and a large amount of inflammatory infiltration. The epithelial structure of the mice in the tinidazole group and the recombinant human osteoprotegerin group was intact and arranged closely and orderly. After intervention, the IL-4 in the tinidazole group and the recombinant human osteoprotegerin group was significantly higher than the model group and IL-6 was significantly lower than the model group (P<0.05), and the recombinant human osteoprotegerin group IL-4 was significantly higher after the intervention. IL-6 was significantly lower in the tinidazole group than in the tinidazole group (P<0.05). After the intervention, the tinidazole group and the recombinant human osteoprotegerin group were significantly reduced, and the recombinant human osteoprotegerin group RAKNL and MCP-1 were significantly lower than the model group (P>0.05). Conclusion: Recombinant human osteoprotegerin combined with tinidazole has a better therapeutic effect on gums and teeth in mice with periodontitis, and can lower the levels of RAKNL and MCP-1 in serum, inhibit bone resorption and protect teeth.展开更多
BACKGROUND： We constructed a homologous recombination bacterial method based on the pAdEasy system, a widely used system, for generating recombinant adenoviral vectors that express glucose transporter- 1 （GLUT 1） i...BACKGROUND： We constructed a homologous recombination bacterial method based on the pAdEasy system, a widely used system, for generating recombinant adenoviral vectors that express glucose transporter- 1 （GLUT 1） in rats, OBJECTIVE： This study was designed to investigate the feasibility of generating recombinant replication-defective adenoviral vectors that express GLUT1 in rats by in vitro ligation based on the Adeno-X^TM system. DESIGN： An in vitro cell-based experiment. SETTING： This study was performed at the Linbaixin Medical Research Center of the Second Hospital Affiliated to Sun Yat-sen University and Central Laboratory for Prevention and Treatment of Tumor, Sun Yat-sen University between January and August 2004. MATERIALS： Male, adult, Sprague Dawley rats were used to extract total RNA from brain tissue. E. coli DH5 a and human embryonic kidney 293 cells （HEK293 cells） used in the present study were cryo-preserved by the Second Hospital Affiliated to Sun Yat-sen University. Rabbit anti-rat GLUT1 polyclonal antibody （Chemicon, U.S.A.） and primers （Shanghai Boya Bioengineering Co., Ltd） were also used. METHODS： E1/E3-deleted replication-defective adenoviral vectors were used. Using in vitro ligation, the target gene was first sub-cloned into a shuttle vector plasmid to obtain the fragment containing target gene expression cassettes by enzyme digestion. Subsequently, the fragment was co-transformed with linearized adenoviral backbone vector into the E. coli strain. The recombinant adenoviral plasmid was transfected into HEK293 cells to assembly recombinant adenoviral vectors with replication capabilities. The procedure was repeated several times for recombinant adenoviral vectors amplification. MAIN OUTCOME MEASURES： Efficiency of recombinant adenoviral vectors to express the target gene was measured by gene and protein expression through polymerase chain reaction and Western Blot assays, respectively. RESULTS： Results demonstrated that recombinant adenoviral vectors successfully expressed GLUT1 protein, with a relative molecular mass of 55000 in HEK293 cells. These results suggest that recombinant adenoviral vectors obtained by homologous bacterial recombination feature high efficiency, rapidness, and simplicity. CONCLUSION： We successfully amplified the rat GLUT1 gene and constructed replication-defective adenoviral vectors expressing GLUT1. The replication-defective adenoviral vectors proved to successfully express the target gene in HEK293 cells.展开更多
Objective To observe the expression of hypoxia inducible factor-1α (HIF-1α) in the retina of rabbits with acute high intraocular pressure and to investigate the mechanism of systemic domestic recombinant human eryth...Objective To observe the expression of hypoxia inducible factor-1α (HIF-1α) in the retina of rabbits with acute high intraocular pressure and to investigate the mechanism of systemic domestic recombinant human erythropoietin (rhEPO) protecting the retina from ischemia-reperfusion injury. Methods First,control group and model group were established in rabbit eyes. The acute high intraocular pressure model was established by saline perfusion into anterior chamber,and then hypodermic injection of domestic rhEPO was made. HIF-1α protein in the retina was observed by immunohistochemical staining method on days 1,3,7 and 14 after retinal ischemia-reperfusion,respectively. Results No cells with HIF-1α positive expression were observed in the retina of the control group. Cells with HIF-1α positive expression in the model group outnumbered those in the control group (P<0.01). The resemblance pattern occurred in EPO group but its degree was slightly greater than that in the model group from day 3 after ischemia-reperfusion (P<0.05). Conclusion Domestic rhEPO can down-regulate the expression of HIF-1α in the retina with acute high intraocular pressure,which may be one of the mechanisms that rhEPO protects the retina from ischemia-reperfusion injury.展开更多
基金financially supported by the National Natural Science Foundation of China(82127802,22374157)Strategic Priority Research Program,CAS(XDB0540000,XDC0170000)CAS Youth Interdisciplinary Team(JCTD-2022-13).In addition,Xin Zhou acknowledges the support from the Tencent Foundation through the XPLORER PRIZE.
文摘Magnetic resonance imaging(MRI)is a powerful tool for diagnosing and monitoring brain diseases,but its low sensitivity can hinder early detection.To address this challenge,we utilized chemical exchange saturation transfer(CEST)MRI,which greatly enhances sensitivity for detecting low-concentration compounds.In this study,we developed a CEST contrast agent based on a recombinant adeno-associated viruses(rAAVs)encoding the protamine-1(PRM1)MRI reporter gene.CEST MRI revealed that PRM1 contrast agent effectively highlighted caudate putamen region after injection of the rAAVs into the mouse brain,clearly distinguishing it from the surrounding tissue,with no observable damage.This method provides a sensitive,metal-free CEST contrast agent for in vivo brain cell detection,demonstrating potential for both diagnostic and therapeutic applications in brain diseases.
基金supported by the National Natural Science Foundation of China,Nos.81730033,82171193(to XG)the Key Talent Project for Strengthening Health during the 13^(th)Five-Year Plan Period,No.ZDRCA2016069(to XG)+1 种基金the National Key R&D Program of China,No.2018YFC2001901(to XG)Jiangsu Provincial Medical Key Discipline,No.ZDXK202232(to XG)。
文摘Postoperative cognitive dysfunction is a seve re complication of the central nervous system that occurs after anesthesia and surgery,and has received attention for its high incidence and effect on the quality of life of patients.To date,there are no viable treatment options for postoperative cognitive dysfunction.The identification of postoperative cognitive dysfunction hub genes could provide new research directions and therapeutic targets for future research.To identify the signaling mechanisms contributing to postoperative cognitive dysfunction,we first conducted Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses of the Gene Expression Omnibus GSE95426 dataset,which consists of mRNAs and long non-coding RNAs differentially expressed in mouse hippocampus3 days after tibial fracture.The dataset was enriched in genes associated with the biological process"regulation of immune cells,"of which Chill was identified as a hub gene.Therefore,we investigated the contribution of chitinase-3-like protein 1 protein expression changes to postoperative cognitive dysfunction in the mouse model of tibial fractu re surgery.Mice were intraperitoneally injected with vehicle or recombinant chitinase-3-like protein 124 hours post-surgery,and the injection groups were compared with untreated control mice for learning and memory capacities using the Y-maze and fear conditioning tests.In addition,protein expression levels of proinflammatory factors(interleukin-1βand inducible nitric oxide synthase),M2-type macrophage markers(CD206 and arginase-1),and cognition-related proteins(brain-derived neurotropic factor and phosphorylated NMDA receptor subunit NR2B)were measured in hippocampus by western blotting.Treatment with recombinant chitinase-3-like protein 1 prevented surgery-induced cognitive impairment,downregulated interleukin-1βand nducible nitric oxide synthase expression,and upregulated CD206,arginase-1,pNR2B,and brain-derived neurotropic factor expression compared with vehicle treatment.Intraperitoneal administration of the specific ERK inhibitor PD98059 diminished the effects of recombinant chitinase-3-like protein 1.Collectively,our findings suggest that recombinant chitinase-3-like protein 1 ameliorates surgery-induced cognitive decline by attenuating neuroinflammation via M2 microglial polarization in the hippocampus.Therefore,recombinant chitinase-3-like protein1 may have therapeutic potential fo r postoperative cognitive dysfunction.
基金supported by the grants from the National Basic Research Development Program of China(No.2007CB516701,2006CB500704)the National Natural Science Foundation of China(No.30770757)
文摘Objective To construct the recombinant adenovirus vector carrying human growth hormone secretagogue receptor type 1a （GHS-R1a） ,for genetic transfection.Methods The full-length human GHS-R1a gene was obtained by PCR amplification and then cloned into the shuttle plasmid pAdTrack-CMV.The linearized plasmid pAdTrack-CMV-GHS-R1a was co-transformed into Escherichia coli （E.coli） BJ5183 cells along with an adenoviral backbone plasmid pAdEasy1.The HEK293 cells were then infected with adenoviruses.The expression of GHS-R1a was indicated by green fluorescent protein （GFP） ,and confirmed by Reverse Transcription Polymerase Chain Reaction （RT-PCR） and Western blot.Results Enzymatic digestion of pAdGHS-R1a yielded a large fragment （approximately 30 kb） and a small fragment （4.5 kb） ,indicating the success-ful construction of recombinant adenovirus expression vector.Expression of GFP was observed by confocal laser scanning microscopy at 24 h after infection.RT-PCR and Western blot further confirmed that GHS-R1a was efficiently expressed in 293 cells.Conclusion Recombinant adenovirus （AdGHS-R1a） is successfully constructed,and the target gene can be expressed efficiently in 293 cells,which provide a valuable tool for further studying the function of GHS-R1a.
基金supported by the National Natural Science Foundation of China(Youth Science Fund Project),No.81901292(to GC)the National Key Research and Development Program of China,No.2021YFC2502100(to GC)the National Natural Science Foundation of China,No.82071183(to ZZ).
文摘Netrin-1 and its receptors play crucial roles in inducing axonal growth and neuronal migration during neuronal development.Their profound impacts then extend into adulthood to encompass the maintenance of neuronal survival and synaptic function.Increasing amounts of evidence highlight several key points:(1)Diminished Netrin-1 levels exacerbate pathological progression in animal models of Alzheimer’s disease and Parkinson’s disease,and potentially,similar alterations occur in humans.(2)Genetic mutations of Netrin-1 receptors increase an individuals’susceptibility to neurodegenerative disorders.(3)Therapeutic approaches targeting Netrin-1 and its receptors offer the benefits of enhancing memory and motor function.(4)Netrin-1 and its receptors show genetic and epigenetic alterations in a variety of cancers.These findings provide compelling evidence that Netrin-1 and its receptors are crucial targets in neurodegenerative diseases.Through a comprehensive review of Netrin-1 signaling pathways,our objective is to uncover potential therapeutic avenues for neurodegenerative disorders.
基金Supported by The Chinese Human Liver Proteome Project, No. 2004BA711A19-08National 863 Project, No.2007AA02Z100
文摘AIM: To evaluate the effects of positive regulation of recombinant human interleukin 1 receptor antagonist (rhIL-1Ra) on hepatic tissue recovery in acute liver injury in mice induced by carbon tetrachloride (CCl 4 ). METHODS: Acute liver damage was induced by injecting 8-wk-old mice with CCl 4 1 mL/kg (1:3 dilution in corn oil) intraperitoneally (ip). Survival after liver failure was assessed by injecting 8-wk-old mice with a lethal dose of CCl 4 2.6 mL/kg (1:1 dilution in corn oil) ip. Mice were subcutaneously injected with 1 mg/kg recombinant human IL-1Ra twice a day after CCl 4 treatment for 5 d. Serum alanine amino transferase (ALT) and aspartate aminotransferase (AST) levels were determined with a commercial assay kit. Serum IL-1β, IL-1Ra levels were measured by enzyme-linked immunosorbent assay kit. Quantitative real-time polymerase chain reaction was used to determine liver IL-1β, IL-1Ra and IL-6 expression during CCl 4-induced acute liver injury. Liver sections were stained with hematoxylin-eosin. A histology-injury grading system was used to evaluate the degree of necrosis after acute liver injury. Proliferating cell nuclear antigen (PCNA) staining was used to evaluate the role of rhIL-1Ra in promoting hepatocyte proliferation. RESULTS: Quantitative analysis showed a higher level of IL-6 mRNA expression and reduced serum AST and ALT levels in the livers of the rhIL-1Ra-treated group at the early phase of CCl 4-induced acute liver injury. Histological examination indicated a decrease in centrilobular necrotic areas in mice treated with rhIL-1Ra, and a novel role of rhIL-1Ra in promoting hepatocyte proliferation was also supported by an increase of PCNA staining. All these results, accompanied by a strong survival benefit in rhIL-1Ra-treated vs PBS-treated groups, demonstrated that rhIL-1Ra administration ameliorated the histological damage and accelerated the regeneration and recovery process of the liver. CONCLUSION: rhIL-1Ra could be further developed as a novel therapeutic agent for the treatment of acute liver injury because of its ability to reduce hepatocellular damage and facilitate liver regeneration.
文摘The recombinant Saccharomyces cerevisiae strain stably expressing recombinant human glucagon-like peptide-l（rhGLP-1） analogue, as a potential oral drug delivery system for diabetes type II treatment, was successfully constructed by the homologous recombination between chromosomal DNA and yeast and integrating vector pNK-GLP containing yeast ribosomal DNA fragments. The amount of rhGLP-I analogue fusion protein in transformant SG2 reached ca. 0.84 mg per gram of packed cells when SG2 was grown for 24 h in the YPD medium with a inoculum and medium ratio of 1：1. Oral administration of 5 g lyophilized SG2/kg to hyperglycemic rats decreased serum glucose from （24.8±1.40） to （21.2±1.36） mmol/L.
基金Science and Technology Development Project of Shandong province (2005GG3202068)
文摘In this study,a standard strain of HSV-1 (strain SM44) was used to investigate the antiviral activity of the recombinant Cyanovirin-N (CV-N) against Herpes simplex virus type 1 (HSV-1) in vitro and in vivo.Cytopathic effect (CPE) and MTT assays were used to evaluate the effect of CV-N on HSV-1 in Vero cells.The number of copies of HSV-DNA was detected by real-time fluorescence quantitative PCR (FQ-PCR).The results showed that CV-N had a low cytotoxicity on Vero cells with a CC50 of 359.03±0.56 μg/mL,and that it could not directly inactivate HSV-1 infectivity.CV-N not only reduced the CPE of HSV-1 when added before or after viral infection,with a 50% inhibitory concentration (IC50) with 2.26 and 30.16μg/mL respectively,but it also decreased the copies of HSV-1 DNA in infected host cells.The encephalitis model for HSV-1 infection was conducted in Kunming mice,and treated with three dosages of CV-N (0.5,5 & 10 mg/kg) which was administered intraperitoneally at 2h,3d,5d,7d post infection.The duration for the appearance of symptoms of encephalitis and the survival days were recorded and brain tissue samples were obtained for pathological examination (HE staining).Compared with the untreated control group,in the 5mg/kg CV-N and 10mg/kg CV-N treated groups,the mice suffered light symptoms and the number of survival days were more than 9d and 14d respectively.HE staining also showed that in 5mg/kg CV-N and 10mg/kg CV-N treated groups,the brain cells did not show visible changes,except for a slight inflammation.Our results demonstrated that CV-N has pronounced antiviral activity against HSV-1 both in vitro and in vivo,and it would be a promising new candidate for anti-HSV therapeutics.
文摘Objective.To construct recombinant BCG again st leptospirosis.Methods.We amplified the entire open readin g frame of the OmpL1gene from the genome of the leptospire serovar Lai strain 017.Two recombin ant plasmids pBQ1and pBQ2were constructed by oriented ligation based on the E.coli-BCG shuttle plasmids pMV261and pMV361respectively.The recombinant plasmids were transformed into BCG by electroporation.The rBCGs bearing pBQ1and pBQ2were induced by high temperature of 45℃.Results.The expressed product,a 35kD prote in was detected by SDS-PAGE.The resu lt indicates that pBQ1and pBQ2can express OmpL1in rBCG.Conclusion.The technical methods in this study may help detect the immunogenicity a nd immunoprotection of OmpL1and develop more safe,highl y effective rBCG bearing leptospira l antigen with long-lasting protection.
基金supported by a grant from the National Basic Research Program of China(2013CB127804)the National Natural Science Funds(31171696,China)the Research Program of the State Key Laboratory of Food Science and Technology,Nanchang University(SKLF-MB-201002)
文摘Some unique subclasses of Camelidae antibodies are devoid of the light chain, and the antigen binding site is comprised exclusively of the variable domain of the heavy chain （VHH）. The recombinant VHHs have a high potential as alternative reagents for the next generation of immunoassay. In particular, they might be very useful for molecular mimicry. The present study demonstrated an alpaca immunized with the F（ab＇）z fragment of anti-aflatoxin B1 mAb and developed an important anti-idiotypic （anti-ld） responses. Antigen-specific elution method was used for panning private anti-ld VHHs from the constructed alpaca VHH library. The selected VHHs were expressed, renatured, purified, and then identified by a competitive enzyme-linked immunosorbent assay （ELISA）. Our findings indicated that the VHH would be an alternative tool for haptens mimicry studies.
文摘Objective: To investigate the effect of recombinant human osteoprotegerin combined with tinidazole on mice with periodontitis and the effect on serum RANKL and MCP-1 levels. Methods: 80 SPF-cleaned mice were randomly divided into 4 groups, 20 each, model group, tinidazole group and recombinant human osteoprotegerin group were modeled by Kimura et al., and tinidazole group received tinidazole. After intragastric administration, the recombinant human osteoprotegerin group was injected with recombinant human osteoprotegerin in the periodontal pocket according to the tinidazole group. The periodontal changes of the four groups of mice were observed and recorded, and the gingival rating was performed. Epithelial tissue morphology was observed by hematoxylin-eosin (HE) staining. Serum levels of IL-4, IL-6, RANKL and MCP-1 were measured by enzyme-linked immunosorbent assay. Results:After the intervention, the model group developed severe inflammatory reactions, including redness, hemorrhage, and deep periodontal pockets. The teeth were significantly loosened. The mice in the tinidazole group and the recombinant human osteoprotegerin group recovered substantially, and the gingival rating of the recombinant human osteoprotegerin group was better than that. The tinidazole group and the model group (P<0.05). The results of HE staining showed that the model group had edema, vasodilation and a large amount of inflammatory infiltration. The epithelial structure of the mice in the tinidazole group and the recombinant human osteoprotegerin group was intact and arranged closely and orderly. After intervention, the IL-4 in the tinidazole group and the recombinant human osteoprotegerin group was significantly higher than the model group and IL-6 was significantly lower than the model group (P<0.05), and the recombinant human osteoprotegerin group IL-4 was significantly higher after the intervention. IL-6 was significantly lower in the tinidazole group than in the tinidazole group (P<0.05). After the intervention, the tinidazole group and the recombinant human osteoprotegerin group were significantly reduced, and the recombinant human osteoprotegerin group RAKNL and MCP-1 were significantly lower than the model group (P>0.05). Conclusion: Recombinant human osteoprotegerin combined with tinidazole has a better therapeutic effect on gums and teeth in mice with periodontitis, and can lower the levels of RAKNL and MCP-1 in serum, inhibit bone resorption and protect teeth.
基金the National Natural Science Foundation of China, No. 39900048the Natural Science Foundation of Guangdong Province, No.010721
文摘BACKGROUND： We constructed a homologous recombination bacterial method based on the pAdEasy system, a widely used system, for generating recombinant adenoviral vectors that express glucose transporter- 1 （GLUT 1） in rats, OBJECTIVE： This study was designed to investigate the feasibility of generating recombinant replication-defective adenoviral vectors that express GLUT1 in rats by in vitro ligation based on the Adeno-X^TM system. DESIGN： An in vitro cell-based experiment. SETTING： This study was performed at the Linbaixin Medical Research Center of the Second Hospital Affiliated to Sun Yat-sen University and Central Laboratory for Prevention and Treatment of Tumor, Sun Yat-sen University between January and August 2004. MATERIALS： Male, adult, Sprague Dawley rats were used to extract total RNA from brain tissue. E. coli DH5 a and human embryonic kidney 293 cells （HEK293 cells） used in the present study were cryo-preserved by the Second Hospital Affiliated to Sun Yat-sen University. Rabbit anti-rat GLUT1 polyclonal antibody （Chemicon, U.S.A.） and primers （Shanghai Boya Bioengineering Co., Ltd） were also used. METHODS： E1/E3-deleted replication-defective adenoviral vectors were used. Using in vitro ligation, the target gene was first sub-cloned into a shuttle vector plasmid to obtain the fragment containing target gene expression cassettes by enzyme digestion. Subsequently, the fragment was co-transformed with linearized adenoviral backbone vector into the E. coli strain. The recombinant adenoviral plasmid was transfected into HEK293 cells to assembly recombinant adenoviral vectors with replication capabilities. The procedure was repeated several times for recombinant adenoviral vectors amplification. MAIN OUTCOME MEASURES： Efficiency of recombinant adenoviral vectors to express the target gene was measured by gene and protein expression through polymerase chain reaction and Western Blot assays, respectively. RESULTS： Results demonstrated that recombinant adenoviral vectors successfully expressed GLUT1 protein, with a relative molecular mass of 55000 in HEK293 cells. These results suggest that recombinant adenoviral vectors obtained by homologous bacterial recombination feature high efficiency, rapidness, and simplicity. CONCLUSION： We successfully amplified the rat GLUT1 gene and constructed replication-defective adenoviral vectors expressing GLUT1. The replication-defective adenoviral vectors proved to successfully express the target gene in HEK293 cells.
基金supported by the Science and Technology Research Foundation of Shaanxi Province,China(No.2008K14-07)the Medical and Phar macologic Research Foundation of Xi'an City,China(No.SF08004-2)
文摘Objective To observe the expression of hypoxia inducible factor-1α (HIF-1α) in the retina of rabbits with acute high intraocular pressure and to investigate the mechanism of systemic domestic recombinant human erythropoietin (rhEPO) protecting the retina from ischemia-reperfusion injury. Methods First,control group and model group were established in rabbit eyes. The acute high intraocular pressure model was established by saline perfusion into anterior chamber,and then hypodermic injection of domestic rhEPO was made. HIF-1α protein in the retina was observed by immunohistochemical staining method on days 1,3,7 and 14 after retinal ischemia-reperfusion,respectively. Results No cells with HIF-1α positive expression were observed in the retina of the control group. Cells with HIF-1α positive expression in the model group outnumbered those in the control group (P<0.01). The resemblance pattern occurred in EPO group but its degree was slightly greater than that in the model group from day 3 after ischemia-reperfusion (P<0.05). Conclusion Domestic rhEPO can down-regulate the expression of HIF-1α in the retina with acute high intraocular pressure,which may be one of the mechanisms that rhEPO protects the retina from ischemia-reperfusion injury.
