Recombinant chitinase-3-like protein 1 alleviates learning and memory impairments via M2 microglia polarization in postoperative cognitive dysfunction mice

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.

Expression and Evaluation of Wb-SXP-1 and Wb-123 Recombinant Antigens as Potential Diagnostic Biomarkers for Lymphatic Filariasis

Lymphatic filariasis (LF) remains a public health concern as it can cause permanent morbidity and disability to those infected. While the global elimination of LF in these endemic areas is ongoing through mass drug administration, there is the need to develop diagnostic tools that would be utilized to track the progress of total global eradication as well as perform surveillance for the recurrence of lymphatic filariasis transmission. Currently, approved LF diagnosis tools are faced with lack of specificity, low sensitivity, and periodicity dependence. Recombinant filarial antigen-based assays can address these drawbacks and offer practical instruments for LF diagnosis and surveillance. This present study, evaluated rWb-SXP-1 and rWb-123 antigens as potential diagnostic biomarker tools for Wuchereria banchrofti in human sera using microspheres-based multiplex serological assay. Based on statistical analysis using XLSTAT 2019 (Addinsoft) on data generated from multiplex technology assay, generated ROC curves for both rWb-SXP-1 and rWb-123 demonstrated 87.1% sensitivity to Wuchereria banchrofti human sera with rWb-SXP-1 antigens having the highest specificity of 96%. Indication that rWb-SXP-1 and rWb-123 antigens are capable of detecting immunoglobulin G4 (IgG4) antibodies in human sera synthesized specifically against W. banchrofti infections. Therefore, rWb-SXP-1 and rWb-123 antigens can be utilized to detect W. banchrofti infections by antibody profiling with excellent diagnostic sensitivity and specificity using microsphere-based multiplex serological tests. This method can be particularly practical for screening a large number of sera samples and/or for quick, extensive field-testing due to the high-throughput and quick formats applied.

Use of recombinant human bone morphogenetic protein-2 in spine surgery

Bone morphogenetic proteins are osteoinductive factors which have gained popularity in orthopaedicsurgery and especially in spine surgery. The use of recombinant human bone morphogenetic protein-2 has been officially approved by the United States Food and Drug Administration only for single level anterior lumbar interbody fusion, nevertheless it is widely used by many surgeons with off-label indications. Despite advantages in bone formation, its use still remains a controversial issue and several complications have been described by authors who oppose their wide use.

CLINICAL EVALUATION OF FOUR RECOMBINANT TREPONEMA PALLIDUM ANTIGEN-BASED RAPID TESTS IN THE DIAGNOSIS OF SYPHILIS

Objective To assess the sensitivity, specificity, and feasibility of 4 recombinant Treponema pallidum antigenbased rapid tests in the diagnosis of syphilis. Methods A total of 970 outpatients were selected from the Sexually Transmitted Diseases Centre of Peking Union Medical College Hospital. Venous blood was collected and serum was extracted. T. paUidum antibodies in whole blood, anticoagulant whole blood, and serum were detected using 4 recombinant T. pallidum antigen-based rapid tests. T. pallidum haemagglutination test （TPHA） was considered as the gold standard for the detection of T. pallidum specific antibodies in serum. The sensitivities and specificities of four methods were analyzed. Results The sensitivities and specificities of Abbott Determine Syphilis TP test, SD-BIOLINE Syphilis 3.0 test, VISITECT-SYPHILIS test, and Syphicheck-WB test for serum specimens were 100% and 98. 9%, 95.7% and 98.0%, 94.6% and 98.2%, 68.1% and 98.9% ; for whole blood were 74. 1% and 99. 5%, 87.9% and 99.4% , 73.2% and 99.7%, 64. 7% and 99.7%. The observed sensitivities of the 4 rapid diagnosis tests were not significantly different with TPHA （ P 〉 0.05 ）. Conclusions The 4 rapid tests show good performance and characteristics in the diagnosis of syphilis. Furthermore, they are more sensitive for serum specimens than whole blood.

Enzyme-Linked Immunosorbent Assays Using the Recombinant gp51 and p24 of Bovine Leukemia Virus for Immunodetection of the Disease

Enzyme-linked immunosorbent assay (ELISA) is often used to test bovine leukemia virus (BLV) infection. However, commercially available kits test in South America detect only antibodies against the gp51 protein. With the aim to improve the sensitivity of the test, we developed here a two-step indirect dual ELISA test that included both proteins p24 and gp51, expressed and produced in E. coli and baculovirus expression system respectively. Two hundred ten BLV sera, stated as double positive or double negative by the combination of commercial agar gel immunodiffusion (AGID) assay and a gp51-ELISA test, were tested with our in house dual rp24/rgp51 ELISA. Firstly, we checked the purified, optimized and standardized proteins as antigen by the checkerboard technique, and set up our in house ELISA test. The concordance correlation coefficient (CCC) and coefficient of variation (CV) intraplate repeatability levels were within the values established by the international standards. The statistical analysis demonstrated the value of sera correctly ranked highest (93.48%), and for 0.3 cutoff, the sensitivity was 95.65% and the specificity 91.30%. In conclusion, the rp24/rgp51 ELISA developed and standardized here demonstrated to have good analytical characteristics to be considered for screening of BLV.

Antitumor Activity of Recombinant Antimicrobial Peptid Penaeidin-2 against Kidney Cancer Cells

Penaeidin-2（Pen-2） is an important antimicrobial peptide derived from the Pacific white shrimp, Penaeus vannamei, and possesses both antibacterial and antifungal activities. Recent studies suggest that recombinant penaeidins show similar activities to the native Pen-2 protein. Previous researches have shown that some antimicrobial peptides（AMPs） exhibit cytotoxic activity against cancer cells. To date, there have been no studies on the antitumor effects of Pen-2. This study evaluated the potential of recombinant pen-2（rPen-2） in the selective killing of kidney cancer cell lines ACHN and A498, and its action mechanism. MTT assays found the maximal growth inhibition of HK-2, ACHN and A498 cells treated with 100 μg/mL rPen-2 at 48 h was 13.2%, 62.4%, and 70.4%, respectively. DNA-specific fluorescent dye staining showed a high percentage of apoptosis on cancer cells. Flow cytometry revealed that the apoptosis rate of HK-2, ACHN and A498 cells was 15.2%, 55.2%, and 61.5% at 48 h respectively, suggesting that rPen-2 induced higher apoptosis rate in cancer cells than in HK-2 cells. Laser confocal scanning microscopy demonstrated that the plasma membrane was the key site where rPen-2 interacted with and destroyed tumor cells. Scanning electron microscopy showed the morphologic changes of the cell membranes of kidney cancer cells treated with rPen-2. These results suggest that rPen-2 is a novel potential therapeutic agent that may be useful in treating kidney cancers.

Serum tumor markers (carcinoembryonic antigen, carbohydrate antigen 19-9, carbohydrate antigen 72-4, carbohydrate antigen 24-2, ferritin) and gastric cancer prognosis correlation

BACKGROUND Gastric cancer is a kind of malignant tumor which is prevalent all over the world.Although some progress has been made in the treatment of gastric cancer,its prognosis is still not optimistic,so it is of great significance to find reliable prog-nostic indicators to guide the treatment and management of patients with gastric cancer.AIM To explore the relationship between serum levels of five biomarkers[carcinoem-bryonic antigen(CEA),carbohydrate antigen(CA)19-9,CA72-4,CA24-2,and ferritin]and prognosis in patients with gastric cancer.METHODS This study included 200 patients with gastric adenocarcinoma,and conducted an in-depth analysis of their baseline characteristics,relationship between tumor markers and staging,and prognosis.The study found that CA19-9 has a signi-ficant correlation with tumor stage,the average levels of CA24-2,CEA,CA72-4 and ferritin were slightly increased disregarding the stage of tumor.Survival analysis showed that increases in CEA,CA19-9,CA24-2,and ferritin were all associated with shortened overall survival of patients.Further multivariate ana-lysis revealed that elevated serum CA72-4 levels were an inde-pendent adverse prognostic factor.RESULTS This study reveals that there is a significant correlation between the expression levels of serum tumor markers CEA,CA19-9,CA72-4,CA24-2 and ferritin in patients with gastric cancer and prognosis,and can be used as important indicators for prognostic evaluation of gastric cancer.In particular,markers that appear abnormally elevated initially may help identify gastric cancer patients with poor prognosis.CONCLUSION Serum CEA and CA19-9 play an important role in the prognosis assessment of gastric cancer,and are effective tools to guide clinical practice and optimize individualized treatment strategies for gastric cancer patients.

Recombinant adenovirus-mediated overexpression of 3β-hydroxysteroid-Δ24 reductase

3β-Hydroxysteroid-△24 reductase （DHCR24） is a multifunctional enzyme that localizes to the endoplasmic reticulum and has neuroprotective and cholesterol-synthesizing activities. DHCR24 overexpression confers neuroprotection against apoptosis caused by amyloid β deposition. The present study aimed to construct two recombinant adenoviruses driving DHCR24 expression specifically in neurons. Two SYN1 promoter DNA fragments were obtained from human （h） and rat （r）. Recombinant Ad-r（h）SYN1-DHCR24 was transfected into AD-293, N2A （mouse neuroblastoma）, and MIN6 （mouse pancreatic carcinoma） cells. Western blot analysis showed DHCR24 was specially expressed in 293 and N2A cells, but no specific band was found in MIN6 cells. This demonstrates that the recombinant adenoviruses successfully express DHCR24, and no expression is observed in non-neuronal cells. TUNEL assay results showed apoptosis was inhibited in adenovirus-transfected neurons. Detecting reactive oxygen species by immunoflu- orescence, we found that adenovirus transfection inhibits apoptosis through scavenging excess reactive oxygen species. Our findings show that the recombinant DHCR24 adenoviruses induce neuron-specific DHCR24 expression, and thereby lay the foundation for further studies on DHCR24 gene therapy for Alzheimer＇s disease.

Immunogenicity and protective efficacy of recombinant M2e.Hsp70c(Hsp70_(359–610)) fusion protein against influenza virus infection in mice

New strategies in vaccine development are urgently needed to combat emerging influenza viruses and to reduce the risk of pandemic disease surfacing. Being conserved, the M2 e protein, is a potential candidate for universal vaccine development against influenza A viruses. Mycobacterium tuberculosis Hsp70(mHsp70) is known to cultivate the function of immunogenic antigen-presenting cells, stimulate a strong cytotoxic T lymphocyte(CTL) response, and stop the induction of tolerance. Thus, in this study, a recombinant protein from the extracellular domain of influenza A virus matrix protein 2(M2e), was fused to the C-terminus of Mycobacterium tuberculosis Hsp70(Hsp70c), to generate a vaccine candidate. Humoral immune responses, IFN-γ-producing lymphocyte, and strong CTL activity were all induced to confirm the immunogenicity of M2 e.Hsp70c(Hsp70359–610). And challenge tests showed protection against H1N1 and H9N2 strains in vaccinated groups. Finally these results demonstrates M2 e.Hsp70c fusion protein can be a candidate for a universal influenza A vaccine.

Study on the Preparation of Recombinant Human HSP70 and Its Presenting-Antigen Function

The preparation of recombinant human HSP70 and its presenting antigen function were investigated. Cultured in glucose free M9ZB medium and induced with IPTG and lactose at a final concentration of 0.02 mmol/L and 5 mmol/L respectively, the engineered bacteria carrying expression vector of human HSP70 gene expressed rHSP70 at an efficiency of 60 %. After the purification with DEAE ion exchange chromatography, HSP70 with a purity of higher than 90 % was obtained. The purified product could bind tumor antigen peptide in vitro , and the binding was identified by native PAGE containing 5 % glycerol. HSP70 peptide complex could activate lymphocytes to produce specific cytotoxicity to tumor cells, suggesting that the recombinant human HSP70 could be used as an antigen presenting reagent in tumor therapy.

The development of a recombinant hybrid protein of Plasmodium falciparum and analysis of its antigenicity and protectivity

A hybrid gene encoding several putative protective epitopes from erythrocytic stage antigens (MSA1,MSA2 and RESA) of P. falciparum as well as exgenous T cell enhancer epitopes from interleukin-1 and tetanus toxin was synthesized chemically. This gene (named HGFC) was cloned and connected with another hybrid gene (HPFA) synthesized previously to make a bigger hybrid gene (HGFCAC). HGFC and HGFCAC were cloned in an expression vector pWR450-1 and transformed into E. Coli JM109. The engineered bacteria could express fusion proteins with molecular weights of 65 and 77 kDa after inducing with isopropylthio-β-D-galactoside (IPTG). The expression rate was about 35% of total bacterial proteins. The expressed products showed sepcific immunological reaction with rabbit antibodies against P. falciparum peptide Glu-Glu-Asn-Val-Glu-His-Asp-Ala (EENVEHDA)by Western blotting. The fusion proteins were pruified by precipitation with amonium sulfate. gel filtration and ion-exchange chromatography and the purity was 82%. The purified protein reacted specifically with mouse immune serum against falciparum blood stage antigens by dot enzyme-linked immunosorbent assay (dot-ELISA).The fusion protein was emulsified with Freund's complete adjuvant (FCA) and used to immunize rabbits. The immune serum can recognize P. falciparum erythrocytic stage antigens of Fcc-1/HN strain and Yunnan strain and had weak cross reaction with P. vivax,but had no reaction with P. cynomlogi and P. berghei antigens. The protective effect of the antibody was tested by in vitro inhibition test to cultured falciparum parasites. Preliminary results indicated that the immune sera could effectively reduce the invasion rates of the parasites to red blood cells and inhibit the growth of the in vitro cultured falciparum parasites. The inhibitory capacity of the immune sera to parasite invasion is enhanced as the amount of the sera increases and the incubation time of the sera with the parasites is prolonged.It was shown that after 72 h incubation at 20% concentration with the parasites, the serum can suppress the multiplication of P.falciparum growth in vitro to a level of 80%.The immune sera caused dispersion of the parasite cytoplasm,atrophy of parasites,agglutination of free merozoites and degeneration of schizonts.

Neuronal changes in the retinal ganglion cell layer following recombinant human interleukin-2 intravitreal injection in a rat model of chronically elevated intraocular pressure

Intraperitoneal injection of recombinant human interleukin-2（rhIL-2）inhibits neuronal apoptosis in the chronic ocular hypertension retinal ganglion cell layer.Intravitreous injection was performed on retinal ganglion cells in a Wistar rat model of chronically elevated intraocular pressure to observe the effects of LY294002 and AG490 on retinal ganglion cell survival,macrophage activation,and PI3K/Akt and JAK/STAT activation.The number of retinal ganglion cells in the rhIL-2 treatment group was much greater than in the normal control and phosphate-buffered saline groups.Western blot analysis revealed low Akt and STAT3 protein expression in the retina after 3-hour intravitreous injections of rhIL-2.However,protein expression was increased at 12 hours,but decreased again at 24 hours,with very low expression at 96 hours.LY294002 and AG490,which are inhibitors of the PI3K/Akt and JAK/STAT3 signal pathways,prevented upregulation of Akt and STAT3 protein expression in the retina,respectively.Intravitreous injection of rhIL-2 exhibited neuroprotective effects by decreasing retinal ganglion cell layer damage in a rat model of chronic glaucoma.These results suggest that intravitreal injection of rhIL-2 could induce the PI3K/Akt and JAK/STAT3 signaling pathways to protect retinal ganglion cells in chronically elevated intraocular pressure models.

Optical control after transfection of channelrhodopsin-2 recombinant adenovirus in visual cortical cells

Channelrhodopsin-2 ectopically expressed in the retina can recover the response to blue light in genetically blind mice and rats, but is unable to restore visual function due to optic nerve or optic tract lesions. Long Evans rats at postnatal day 1 were used for primary culture of visual cortical cells and 24 hours later, cells were transfected with recombinant adenovirus carrying channelrhodopsin-2 and green fluorescent protein genes. After 2 4 days of transfection, green fluorescence was visible in the cultured cells. Cells were stimulated with blue light （470 nm）, and light-induced action potentials were recorded in patch-clamp experiments. Our findings indicate that channelrhodopsin-2-recombinant adenovirus transfection of primary cultured visual cortical cells can control the production of action potentials via blue light stimulation.

Implantation of xenogeneic bone combined with recombinant human bone morphogenetic protein-2 into bone defect—An scanning electron microscopic study

To determine the ability of a new type of composite xenogeneic bone grafting to repair bone defect. Methods: The new type of composite xenogeneic bone was obtained by combining the chemically treated cance1lous bone with recombinant human bone morphogenetic protein-2 (rhBMP-2). It was implanted on the bone defect of rabbit. Results: There was a large amount of new bone formation within the combined material and the amount was increasing as the time elapsed. In contrast, there was a lot of fibrous tissue with a little new bone formed on the area of the bone defect when the treated cancellous bone was implanted alone. Conclusion: The results imply that the rhBMP-2 plays a very important role in new bone formation and the composite xenogeneic bone appear to be an ideal material for repair of bone defect.

Emergence of recombinant PCV2 between genotype 2a and 2b in pig herds in Shandong province of China

Since late 2005, the swine industry in Shandong province has experienced a significant increase in postweaning multisystemic wasting syndrome （PMWS）. Porcine circovirus type 2 （PCV2） is one of the major etiologic agents of PMWS. In order to understand the genetic diversity of PCV2 in swine herds in Shandong province, we sequenced six complete genomes of PCV2 between 2005 and 2007. Sequence analysis revealed that all the six PCV2 strains belonged to one genotype （named PCV 2b）. The deduced amino acid sequences of the replication associated protein （coded by ORFI） showed that all the six PCV2 strains belonged to genotype 2a and could be further divided into two clusters. Based on the analysis of the capsid protein （coded by ORF2）, the six PCV2 strains belonged to genotype 2b. All the six strains belonged to recombinant viruses between genotype PCV2a and genotype PCV2b. This study implied that such recombinant PCV2 spread widely in Shandong area and might be the reason that pig death rate associated with PMWS increased in recent years.

STRUCTURE AND EXPRESSION OF EPSTEIN-BARR VIRUS MEMBRANE ANTIGEN IN RECOMBINANT VACCINIA VIRUS

The Epstein-Barr virus membrane antigen was constructed and inserted into vaccinia virus, Tian-tan strain in order to study the effect of this virus on EB infection and tumorogenesis. The EBV-derived membrane antigen was expressed under the control of a 7.5 K promoter of vaccinia virus. The antibody against the membrane antigen of EB virus was produced on rabbits vaccinated with recombinant vaccinia virus.

CORAL AS A CARRIER FOR RECOMBINANT HUMAN BONE MORPHOGENETIC PROTEIN-2

By combining coral with recombinant human bone morphogenetic protein-2 (rhBMP-2), rhBMP-2/coral composite was obtained in this study. Following implantation of the composite into the muscle pouches of mice, cartilage growth was induced in the pores or on the surface of the implants at one week, woven bone at three week and lamellar bone with bone marrow at six week, and coral was absorbed partially. The induced formation of endochondral bone was time-related and rhBMP-2 dose-related. The results of this study indicate that the composite possesses a superior ability of osteogenesis, and coral acts as one of the most suitable rhBMP-2 slowrelease carriers currently available. The composite will be a new type of bone substitute to be used in orthopaedics and maxillofacial surgery.

Study on pharmacodynamics of recombinant interferon α-2b suppository

Objective To investigate the antiviral activity of recombinant interferonα-2b suppository(IFNα-2b)in vivo and in vitro.Methods The cytopathic-effect inhibition assay was applied in this study to investigate the antiviral activity of this drug as well as yingtelong and axiluowei as positive control.The guinea pig model of vaginitis and skin infection caused by HSV-2 infection were established,treated with IFNα-2b suppository at dosages of 60000、180000、540000 IU,using IFNα-2b injection 180000 IU·kg-1 as controls.Score the pathological changes of appearance and skin,the virus activities of vaginal secretion and tissue sections of viginae were assayed after treatment.Results The TD50 of IFN α-2b and yingtelong for Vero cells was(>100)μg·mL-1 and(>100000)IU·mL-1,respectively.The IC50 of IFN α-2b and yingtelong and axiluowei for Herpes virus type 1 was(0.29±0.08)μg·mL-1 and(185.0±28.8)IU·mL-1 and(0.19±0.03)μg·mL-1,respectively.The mean scores for vaginal and skin lesion of the treated groups were lower than those of untreated group.Among these concentrations,the IFNα-2b suppository of 540000 IU·kg-1 group.Showed highest anti-viral activity.The virus activity in vaginal secretion of treated group was lower than that of untreated group too(P<0.01 or P<0.05).Tissue sections of viginae after treatment with IFNα-2b suppository showed significantly therapeutical effects on the degrees of vaginal lesion.At the same dosage,The anti-HSV activity of IFNα-2b suppository was also compared with IFNα-2b injection,the results showed that the activity of suppository of 540000 IU·kg-1 group was similar to that of the injection.Conclusions The IFNα-2b suppository has anti-viruses function both in vivo and in vitro.

Development of novel-nanobody-based lateral-flow immunochromatographic strip test for rapid detection of recombinant human interferon a2b

Recombinant human interferon a2b(rhIFNa2b)is widely used as an antiviral therapy agent for the treatment of hepatitis B and hepatitis C.The current identification test for rhIFNa2b is complex.In this study,an anti-rhIFNa2b nanobody was discovered and used for the development of a rapid lateral flow strip for the identification of rhIFNa2b.RhIFNa2b was used to immunize an alpaca,which established a phage nanobody library.After five steps of enrichment,the nanobody I22,which specifically bound rhIFNa2b,was isolated and inserted into the prokaryotic expression vector pET28a.After subsequent purification,the physicochemical properties of the nanobody were determined.A semiquantitative detection and rapid identification assay of rhIFNa2b was developed using this novel nanobody.To develop a rapid test,the nanobody I22 was coupled with a colloidal gold to produce lateral-flow test strips.The developed rhIFNa2b detection assay had a limit of detection of 1 mg/mL.The isolation of I22 and successful construction of a lateral-flow immunochromatographic test strip demonstrated the feasibility of performing ligand-binding assays on a lateral-flow test strip using recombinant protein products.The principle of this novel assay is generally applicable for the rapid testing of other commercial products,with a great potential for routine use in detecting counterfeit recombinant protein products.