Mapping, expression, and association study of the bovine PSMC1 gene

The 26S ATP-dependent protease is composed of a 20S catalytic proteasome and two PA700 regulatory modules; it plays a central role in many regulatory pathways, such as cell cycle regulation, differentiation, and apoptosis. The PA700 complex is composed of multiple subunits, including at least six related ATPases and approximately 15 non-ATPase polypeptides. PSMC1 (proteasome 26S subunit, ATPase, 1) is one of these ATPases. In this study, we amplified a fragment of 507 bp from intron 9 of the bovine PSMC1 gene and found a SNP (G/A) at position 216 in the PCR fragment. Genotyping of 138 animals from four beef breeds revealed that the average frequency for allele A (G-base) was 0.4271 (0.3269-0.5517); for allele B (A-base) it was 0.5729 (0.4483-0.6731). This SNP is significantly associated with average daily feed intake (P < 0.01), average daily gain, finishing average daily gain, body length, ratio of feed to meat, backfat thickness, and loin-muscle area (P < 0.05). Our experimental data showed that animals with an AA genotype have a significantly lower food intake, grow faster, are longer in the body, and have less backfat and bigger loin muscle; hence, their ratio of feed to meat is significantly lower. We believe that the PSMC1 SNP is a potential candidate marker for marker-assisted selection in these traits. We also found that the bovine PSMC1 gene was expressed mainly in lung, testis, and spleen. In addition, we mapped the bovine PSMC1 gene on BTA10 by an RH mapping method.

Monoclonal antibodies against the nucleocapsid proteins of henipaviruses: production, epitope mapping and application in immunohistochemistry

Four monoclonal antibodies (mAbs) were generated by immunizing BALB/C mice with recombinant nucleocapsid protein (N) of Nipah virus (NiV) and Hendra virus (HeV) expressed in E. coli. Two mAbs each were obtained for the HeV N and NiV N, respectively. All four mAbs displayed specific reactivity with the recombinant N proteins of both viruses by western blot, which was further confirmed by immunofluorescent antibody assay using fixed insect cells infected with recombinant baculoviruses expressing either the HeV or NiV N protein. Epitope mapping using a 12-mer random peptide phage display library revealed two linear antigenic sites of the henipavirus N proteins, KLxR (aa 17-20) and FKREM (aa 446-450), which have not been reported previously. Two of the mAbs were able to specifically recognize HeV antigens by immunohistochemical staining of lung tissue sections of a horse experimentally infected with HeV. These reagents will be a useful addition to the collection of tools essential for further research and improvement in diagnosis of henipaviruses.

Tensile ductility and necking of metallic glass

Metallic glasses have a very high strength, hardness and elastic limit. However, they rarely show tensile ductility at room temperature and are considered quasi-brittle materials. Although these amorphous metals are capable of shear flow, severe plastic instability sets in at the onset of plastic deformation, which seems to be exclusively localized in extremely narrow shear bands approximately 10 nm in thickness. Using in situ tensile tests in a transmission electron microscope, we demonstrate radically different deformation behaviour for monolithic metallic-glass samples with dimensions of the order of 100 nm. Large tensile ductility in the range of 23-45% was observed, including significant uniform elongation and extensive necking or stable growth of the shear offset. This large plasticity in small-volume metallic-glass samples did not result from the branching/deflection of shear bands or nanocrystallization. These observations suggest that metallic glasses can plastically deform in a manner similar to their crystalline counterparts, via homogeneous and inhomogeneous flow without catastrophic failure. The sample-size effect discovered has implications for the application of metallic glasses in thin films and micro-devices, as well as for understanding the fundamental mechanical response of amorphous metals.

Stability of low concentrations of guanine-based antivirals in sucrose or maltitol solutions

Three guanine-based antiviral drugs, entecavir, lobucavir, and acyclovir showed degradation in presence of sucrose in ready-to-use solutions held at 50 degrees C, with more degradation at pH 4 than at pH 6 or 7. LC/MS analysis of the solutions showed isomeric adducts of the drugs and reducing sugars. Sucrose, a disaccharide and a non-reducing sugar, was the source of monosaccharides, the reducing sugars. Sucrose showed pH-dependent hydrolysis at 50 degrees C into two monosaccharides, fructose and glucose, with more sucrose hydrolyzing at pH 4 than pH 6 or 7. Additionally, the three drugs showed pH-dependent degradation at 50 degrees C in fructose and glucose solutions with the following rank order: pH 7>pH 6>pH 4. This indicated that the increased degradation of the drugs in sucrose solutions at pH 4 was mainly due to more hydrolysis of sucrose into fructose and glucose compared to pH 6 or 7, and subsequent reactions of the fructose and glucose with the drugs. Based on structures of the major degradants, it is proposed that the main cause of the degradation was nucleophilic addition of the primary amine group of the drugs to the carbonyl group of the fructose and glucose. This reaction was facilitated as the solution pH increased from 4 to 7. All the drugs showed satisfactory stability regardless of the storage temperature or solution pH in maltitol, an alternate sweetener. The free aldehyde or ketone group in maltitol precursors is reduced to a hydroxyl group after the hydrogenation process making maltitol less susceptible to nucleophilic addition.

Evaluation of transdermal permeability of pentoxifylline gel: in vitro skin permeation and in vivo microdialysis using Wistar rats

The aim of the present work was to evaluate the transdermal permeability of pentoxifylline gel in vitro and in vivo. Gel was prepared with carbomer 934 as the base, and the Wistar rat was chosen as an animal model. The effects of percutaneous enhancers on the transdermal permeability of pentoxifylline gel were investigated by in vitro permeation experiments. Cumulative permeation at different times was determined by HPLC. 3% Azone and 5% propylene glycol were used as collaborative enhancers in an optimal formulation. Topical concentrations at different times were measured by microdialysis in vivo. The transdermal process of pentoxifylline fits to a zero-order kinetic equation, and its release profile remains of the zero-order despite the addition of enhancers. In addition, a good in-vitro-in-vivo correlation was achieved.

Construction and targeting of a 5F11-scFv-methioninase fusion protein for antibody-directed enzyme pro-drug therapy (ADEPT) against neuroblastoma

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Background: Recombinant methioninase (METase) depletes methionine and inhibits tumor growth in preclinical models. 5F11 single-chain variable fragment (scFv) can target fusion proteins (e.g. streptavidin (SA), J. Nucl. Med., 45:867, 2004) preferentially to GD2- positive human neuroblastoma (NB). METase targeted to tumors may release methylselenol from the prodrug selenomethionine for tumor therapy. Methods: 5F11-scFv gene fused upstream of METase in pKK-223–3 to form 5F11-scFv-METase. Fusion protein produced in E. coli and purified by chromatography and endotoxin removal retained enzyme activity. Binding of 5F11-scFv-METase to tumor cells was assayed by indirect immunofluorescence and binding kinetics to GD2 analyzed by surface plasmon resonance. Cytotoxicity against human NB cell lines LAN-1, NMB-7 and SK-N-ER was tested using proliferation inhibition and apoptosis assays. Targeting to NB xenografts was studied by biodistribution using 125I-anti-idiotype 1G8 as the secondary tracking antibody. Results: 5F11-scFv-METase was purified to 84% and 94.1% homogeneity by SDS-PAGE and HPLC, respectively. Enzyme activity was 3.6 units/mg protein. Its avidity (KD=1.72×10-7M) as a dimer compared favorably with the monomeric 5F11-scFv (KD=1.07×10- 7M) and tetrameric 5F11-scFv-SA (KD=2.62×10-9M). Immunofluorescent staining of 5F11-scFv-METase was comparable to 5F11-scFv-SA for LAN-1 and NMB-7. In the presence of 20 μM selenomethionine, IC50 of 5F11-scFv-METase was 0.03, 0.02 and 0.02 units/ml for LAN-1, NMB-7 and SK-N-ER, respectively. When treated with 0.3 units/ml of 5F11-scFv-METase and 20 μM selenomethionine, apoptosis was induced in SK-N-ER by 8 hours, peaking at 24 hours. In biodistribution studies, tumor uptake in LAN-1 xenograft averaged 4.07±0.6% injected dose per gram at 48 hours. Conclusions: 5F11-scFv-METase fusion protein retains enzyme activity and immunoreactivity. It targets to tumors in vivo and activates the pro-drug selenomethionine to effect tumor cytotoxicity. Its potential for tumor-selective methionine depletion as well as in ADEPT applications deserves further studies.

No significant financial relationships to disclose.

Egg whites from eggs of chickens infected experimentally with avian hepatitis E virus contain infectious virus, but evidence of complete vertical transmission is lacking

Avian hepatitis E virus (HEV) is genetically and antigenically related to human HEV. Vertical transmission of HEV has been reported in humans, but not in other animals. In this study, we showed that avian HEV could be detected in chicken egg-white samples. Subsequently, avian HEV in egg white was found to be infectious, as evidenced by the appearance of viraemia, faecal virus shedding and seroconversion in chickens inoculated with avian HEV-positive egg white, but not in chickens inoculated with HEV-negative egg white. To further assess the possibility of vertical transmission of avian HEV, batches of embryonated eggs from infected hens were hatched, and hatched chicks were monitored for evidence of avian HEV infection. However, no virus was detected in samples collected from the hatched chicks throughout this study, suggesting that avian HEV could not complete the vertical transmission cycle. The possible implications of our findings are also discussed.

Prolonged cardiac allograft survival in presensitized rats after a high activity Yunnan-cobra venom factor therapy

Complement-dependent antibody-mediated acute humoral rejection is the major obstacle of clinical transplantation across ABO incompatibility and human leukocyte antigen presensitization. We previously demonstrated that Yunnan-cobra venom factor (Y-CVF) could almost completely abrogate complement activity and successfully prevent hyperacute rejection in some xenotransplant models without any obvious toxicity. In this study we investigated whether depletion of complement by Y-CVF prevented acute humoral allograft rejection in presensitized rats thereby prolonging graft survival.

METHODS

Presensitization was achieved in Lewis rats by sequential grafting of three full-thickness skin pieces from Brown Norway rats. Serum cytotoxic alloantibody titers were determined by a modified in vitro complement-dependent microcytotoxicity assay. After presensitization, each Lewis rat received a heterotopic Brown Norway cardiac allograft. Fifteen recipients were divided into two groups: (1) no treatment control (n = 7); (2) Y-CVF therapy group (86 u/kg, IV, day -1) (n = 8). After cessation of the heart beat, allograft rejection was confirmed by pathologic as well as IgG and C3 immunohistochemical examinations.

RESULTS

The mean graft survival time was significantly prolonged to 99.50 +/- 38.72 hours among rats that received Y-CVF vs 12.71 +/- 13.94 hours in nontreated controls (P < .001). Upon pathological and immunohistochemical examination, acute humoral rejection was mainly exhibited in the control group, whereas acute cellular rejection was mainly displayed in the Y-CVF therapy group.

CONCLUSIONS

Our study demonstrated that complement depletion by Y-CVF significantly inhibited acute humoral allograft rejection in presensitized rats. As a therapeutic immunointervention tool for complement, Y-CVF has shown potential efficacy across ABO incompatible and positive cross-match barriers.

Experimental study on genistein prevention and treatment of transplant arteriosclerosis in aortic transplants of rat

OBJECTIVE

Our objective was to study the effects of genistein, a soy isoflavone, on transplant arteriosclerosis, in addition to its immunosuppressive and antioxidant properties.

MATERIALS AND METHODS

We performed male Brown-Norway to male Lewis aortic transplantation. The recipients were randomly assigned to 3 groups: no treatment controls, dimethyl sulfoxide (DMSO; 5 mL/kg) solvent controls, and experimental group that received genistein (20 mg/kg/d) by daily intraperitoneal injection. On postoperative day 60, the graft was harvested and blood obtained. The transplanted aorta was analyzed by histology and immunohistochemistry. The serum was analyzed by an enzyme-linked immunosorbent assay (ELISA).

RESULTS

Compared with the 2 controls, leukocyte recruitment to the graft was significantly inhibited by genistein, with a profound reduction in the number of CD69 macrophages infiltrating the adventitia of the transplanted aortas. Moreover, genistein significantly inhibited the expression of VEGF and IFN-gamma production (P < .01).

CONCLUSION

These results suggested that the protein tyrosine kinase inhibitor genistein inhibited graft arteriosclerosis.

Antisense ERK1/2 oligodeoxynucleotide gene therapy attenuates graft arteriosclerosis of aortic transplant in a rat model

Chronic rejection is a major cause of transplant loss that is effected by the extracellular signal-regulated kinases (ERK) pathway. This study investigated the effects of antisense ERK1/2 oligodeoxynucleotide(ODN) gene therapy on chronic rejection.

METHODS

Lewis (RT1(1)) rats served as recipients of Brown-Norway (BN, RT1n) grafts. The BN rat abdominal aortas were harvested and orthotopically grafted into Lewis rats. The recipients were divided into three groups: (1) control group (n = 9), (2) random ODN transfer group (n = 10), and (3) antisense ODN transfer group (n = 10). At day 60 after transplantation, the recipients were sacrificed; the grafted aortas were evaluated histologically and immunohistochemically. ERK1/2 protein expression in the grafts was determined using Western Blot assays. Serum levels of slCAM-1 were detected by ELISA.

RESULTS

In the control group and random ODN transfer group, we observed a remarkable degree of intimal hyperplasia and inflammatory cell infiltration, including macrophages and T cells. Compared with the control group, antisense ERK1/2 ODN gene therapy resulted in a significant reduction in neointimal proliferation (P < .01), inhibition of ERK1/2 protein expression (P < .01), decreased graft infiltration with CD4+ T lymphocytes (P < .01), CD8+ T lymphocytes(P < .05), and ED-1 macrophages (P < .01) with decreased serum levels of sICAM-1 (P < .05). We obtained a negative correlation between ERK1/2 expression and immune cell infiltration or ICAM-1 level.

CONCLUSIONS

Antisense ERK1/2 gene therapy can attenuate graft arteriosclerosis so as to protect aortic allografts. The protection seemed to correlate with inhibition of inflammatory infiltration, implying that the ERK1/2 signal transduction pathway plays an important role in the process of chronic vascular rejection.

Association of the 54-nucleotide repeat polymorphism of hPer3 with heroin dependence in Han Chinese population

Circadian clock genes have the function of producing circadian rhythm. They are also implicated in the origin or development of many diseases such as cancers and neuropsychiatric diseases. The purpose of this study is to determine whether the 54-nucleotide repeat polymorphism of hPer3, one of the circadian clock genes, associates with heroin dependence. DNA samples were obtained from 209 Chinese heroin-dependent subjects and 249 Chinese healthy controls. The 54-nucleotide repeat polymorphism was detected by polymerase chain reaction and DNA agarose gel electrophoresis. The frequency of four-repeat allele was significantly higher (chi(2)= 10.64, P = 0.001; corrected for multiple tests, P = 0.003) in the mixed gender heroin-dependent subject group (four repeat: 0.89, five repeat: 0.11) than in the mixed gender control group (four repeat: 0.81, five repeat: 0.19); the frequency of four-repeat allele was also significantly higher (chi(2)= 10.00, P = 0.002; corrected for multiple tests, P = 0.006) in the male heroin-dependent subject group (four repeat: 0.89, five repeat: 0.11) than in the male control group (four repeat: 0.81, five repeat: 0.19); for females, no significant trend was observed with the 54-nucleotide repeat polymorphism between the heroin-dependent subject group and the control group. Our results suggest that the 54-nucleotide repeat polymorphism of hPer3 significantly associates with heroin dependence at the allele frequency level and may be a potential risk factor for the development of heroin dependence.

Protection of chickens against avian hepatitis E virus (avian HEV) infection by immunization with recombinant avian HEV capsid protein

Avian hepatitis E virus (avian HEV) is an emerging virus associated with hepatitis-splenomegaly syndrome in chickens in North America. Avian HEV is genetically and antigenically related to human HEV, the causative agent of hepatitis E in humans. In the lack of a practical animal model, avian HEV infection in chickens has been used as a model to study human HEV replication and pathogenesis. A 32 kDa recombinant ORF2 capsid protein of avian HEV expressed in Escherichia coli was found having similar antigenic structure as that of human HEV containing major neutralizing epitopes. To determine if the capsid protein of avian HEV can be used as a vaccine, 20 chickens were immunized with purified avian HEV recombinant protein with aluminum as adjuvant and another 20 chickens were mock immunized with KLH precipitated in aluminum as controls. Both groups of chickens were subsequently challenged with avian HEV. All the tested mock-immunized control chickens developed typical avian HEV infection characterized by viremia, fecal virus shedding and seroconversion to avian HEV antibodies. Gross hepatic lesions were also found in portion of these chickens. In contrast, none of the tested chickens immunized with avian HEV capsid protein had detectable viremia, fecal virus shedding or observable gross hepatitis lesions. The results from this study suggested that immunization of chickens with avian HEV recombinant ORF2 capsid protein with aluminum as adjuvant can induce protective immunity against avian HEV infection. Chickens are a useful small animal model to study anti-HEV immunity and pathogenesis.

Slow, nondiffusive dynamics in concentrated nanoemulsions

Using multispeckle x-ray photon correlation spectroscopy, we have measured the slow, wave-vector-dependent dynamics of concentrated, disordered nanoemulsions composed of silicone oil droplets in water. The intermediate scattering function possesses a compressed exponential line shape and a relaxation time that varies inversely with wave vector. We interpret this dynamics as strain in response to local stress relaxation. The motion includes a transient component whose characteristic velocity decays exponentially with time following a mechanical perturbation of the nanoemulsions and a second component whose characteristic velocity is essentially independent of time. The steady-state characteristic velocity is surprisingly insensitive to the droplet volume fraction in the concentrated regime, indicating that the strain motion is only weakly dependent on the droplet-droplet interactions.

Interaction between proximal tubular epithelial cells and infiltrating monocytes/T cells in the proteinuric state

We hypothesize an interaction between T cells/monocytes and the tubules in the development of tubulointerstitial injury in chronic proteinuric nephropathy. We established in vitro co-culture systems of proximal tubular epithelial cells (PTEC) and T cells/monocytes to study the contribution of soluble factors and cell-to-cell contact in the development of tubulointerstitial injury. The release of monocyte chemoattractant protein-1 (MCP1 or CCL2), Regulated upon Activation, normal T cell Expressed and Secreted (RANTES or CCL5), soluble intracellular adhesion molecules-1 (sICAM-1), or interleukin-6 (IL-6) was increased in PTEC following apical exposure to human serum albumin (HSA). The release of CCL2, CCL5, or sICAM-1 from PTEC was enhanced by contact of monocytes/T cells on the basolateral surface. Tumor necrosis factor-alpha (TNF-alpha) and IL-1beta are important soluble factors as suggested by the blocking effect of antibodies (Abs) against TNF-alpha or IL-1beta but not against other cytokines. The percentage of CD4+ T cells expressing both chemokine receptors, CCR2 and CCR5, was increased after culturing with supernatant from the apical or basolateral surface of PTEC following apical exposure to HSA. However, only CCR2 was upregulated in CD8+ T cells, whereas CCR5 expression was increased in monocytes. The chemotaxis of CD4+ or CD8+ T cells to supernatant from PTEC upon apical exposure to HSA was reduced with neutralizing Abs against CCL5 and/or CCL2, whereas the chemotaxis of monocytes was only reduced by anti-CCL5 but not by anti-CCL2. In summary, chemokines released by HSA-activated PTEC are amplified by monocytes/T cells. Mediators released by HSA-activated PTEC can differentially modulate the expression of chemokine receptors in monocytes/T cells and hence, alter their chemotaxis towards activated PTEC. These interactions are pivotal in the development of tubulointerstitial injury.

Expression of Neuropilin-1 In Kidney Graft Biopsies: What Is the Significance?

OBJECTIVE

Recent work has suggested that neuropilin-1 (NRP-1) is a surface marker of regulatory T cells (Treg). However, no further relative evidence has been provided to confirm this finding. Since Treg should decline during rejection, the expression of NRP-1 on lymphocytes should decline in a rejected graft. To test this proposal, we examined NRP-1 expression in kidney graft biopsies.

MATERIALS AND METHODS

Tissue samples were obtained from 20 kidney graft biopsies with pathologically confirmed acute rejection and from 10 without rejections. We performed immunohistochemistry assays using an anti-NRP-1 monoclonal antibody. The positive cells were counted and the ratios among lymphocytes analyzed.

RESULTS

Compared with samples from nonrejected graft biopsies (18.71 +/- 20.60), the number of positive cells among lymphocytes in the rejected samples showed a lower percentage (3.16 +/- 1.72; P < .05).

CONCLUSIONS

NRP-1 has an important role in directing the growth of nervous synapses and immune synapses. We found in rejected grafts that the percentage of NRP-1 positive cells among lymphocytes decreased significantly. Therefore, NRP-1 may have a previously unrecognized role to predict the immune state of the graft as a potential marker for Treg.

A new meroditerpenoid from Mayodendron igeum

A new meroditerpenoid, igeumone (1), together with 18 known compounds (2-19), were isolated from ethanolic extract of the bark of Mayodendron igeum. Their structures were determined by analysis of spectral data or comparison with authentic samples. X-ray crystallographic analysis was employed to unambiguously determine the structure of 1.

Adenovirus-Mediated Antisense-ERK2 Gene Therapy Attenuates Chronic Allograft Nephropathy

BACKGROUND

The aim of this study was to investigate the effects of adenovirus-mediated antisense ERK2 (Adanti-ERK2) gene therapy on chronic allograft nephropathy.

METHODS

We employed a rat kidney transplantation mode (F344-->Lewis) and studied four groups: (1) controls (n = 6); (2) vector controls (n = 6); (3) an Adanti-ERK2 group (n = 10); and (4) an isograft group (n = 4). The animals were monitored for proteinuria, graft histology, infiltrating cells, and immune-related gene (interleukin-2 [IL-2] and intracellular adhesion molecule-1 [ICAM-1]) expression for 20 weeks after transplantation.

RESULTS

The control group had increasing proteinuria during the 20-week follow-up. All rats showed advanced chronic renal failure associated with strong immune cell infiltration and immune gene expression. Chronic graft injury was accelerated in the vector-control group, but no significant difference was observed compared with the control group. In contrast, the Adanti-ERK2 group showed less inflammation and improved graft histology/function compared with controls. Moreover, ERK2 protein expression in the Adanti-ERK2 group was lower than in the control group (P < .05) and vector-control group (P < .05). Furthermore, serial estimates of genes (IL-2, ICAM-1) related to chronic rejection showed significant downregulation in the Adanti-ERK2 group (P < .01).

CONCLUSIONS

Adenovirus-mediated antisense ERK2 gene therapy attenuated chronic allograft nephropathy. The protective effects of antisense ERK2 gene therapy may have derived from a blocked ERK signal transduction pathway, which reduced ERK expression as well as those of immune-related genes.