IL8 and EDEM3 gene expression ratio indicates peripheral blood mononuclear cell (PBMC) quality.

BACKGROUND: Uncontrolled preanalytical variables can reduce the accuracy and reproducibility of downstream analytical results from peripheral blood mononuclear cells (PBMCs). METHODS: PBMCs were isolated from EDTA and citrate-anticoagulated blood samples, obtained from healthy subjects and patients with inflammatory and infectious conditions. PBMC-derived RNA samples were examined for gene expression changes induced by extended blood pre-centrifugation delays at 4 °C and RT. We used Taqman RTqPCR to evaluate the combination of two target genes for their "diagnostic performance" in identifying EDTA and citrate-anticoagulated PBMC samples with extended pre-centrifugation times. RESULTS: We established the PBMC preanalytical score, a gene expression metric to asses the PBMC quality related to the pre-centrifugation delay at room temperature for different anticoagulants. The PBMC preanalytical score measurement can identify: CONCLUSION: The proposed PBMC preanalytical score may enable objective PBMC sample qualification for downstream applications, which may be influenced by blood precentrifugation delays.

α-Mannosidase I Protein Expression in Peripheral Blood Mononuclear Cells Is Upregulated During Hepatitis B Virus Infection.

Hepatitis B virus (HBV) has been reported to be recognized by dendritic cell-specific ICAM-3-grabbing nonintegrin in the presence of the α-mannosidase I inhibitor kifunensine, whereas native HBV is not. The aim of our study was to determine whether changes in α-mannosidase I expression in peripheral blood mononuclear cells (PBMCs) occur in patients with HBV infection. Peripheral blood was collected from 90 HBV-infected patients (grouped into immune tolerance, chronic hepatitis B, or inactive carrier group based on their clinical states) and 30 healthy donors. Expression of the three α-mannosidase I subtypes, MAN1A1, MAN1A2, and MAN1C1, was measured using western blot analyses. Compared with the healthy controls, significant increases in the MAN1A1, MAN1A2, and MAN1C1 expression levels were observed in the three HBV-infected groups, among whom the immune tolerance group showed the largest increase. For the patients in the immune tolerance phase, the expression levels of both MAN1A1 and MAN1A2 were linearly and positively correlated with the hepatitis B e antigen (HBeAg) titer and HBV DNA level, although a positive correlation was only found between MAN1C1 expression and the HBeAg titer. These results indicate that increased α-mannosidase I expression in PBMCs may play an important role in HBV immune escape and that its expression level is closely related to viral replication activity.

Determination of lysosomal exoglycosidases in human saliva.

BACKGROUND: Currently we observe a growing interest in human saliva as a non-invasive material for diagnosis and monitoring of general and oral diseases. METHODS: The aim of our study was adaptation of the Marciniak et al. (Marciniak J, Zalewska A, Popko J, Zwierz K, 2006, Clin Chem Lab Med 44: 933-937) method for determination of HEX and GLU activity in synovial fluid, and for determination of: HEX and GLU, as well as MAN, GAL, and FUC activity in human saliva. RESULTS: Under optimal conditions, 10 µl of saliva for HEX, and 30 µl for GLU, MAN, GAL and FUC, were sufficient for determination of human salivary exoglycosidases activity with variation coefficient ranging from 0.89 for GLU to 0.99 for GAL. CONCLUSION: The adapted method for exoglycosidases activity determination in human saliva is sufficiently sensitive and precise to use in clinical diagnosis.

Endoplasmic reticulum stress in alveolar epithelial cells is prominent in IPF: association with altered surfactant protein processing and herpesvirus infection.

Recent evidence suggests that dysfunctional type II alveolar epithelial cells (AECs) contribute to the pathogenesis of idiopathic pulmonary fibrosis (IPF). Based on the hypothesis that disease-causing mutations in surfactant protein C (SFTPC) provide an important paradigm for studying IPF, we investigated a potential mechanism of AEC dysfunction suggested to result from mutant SFTPC expression: induction of endoplasmic reticulum (ER) stress and the unfolded protein response (UPR). We evaluated biopsies from 23 IPF patients (including 3 family members with L188Q SFTPC mutations, 10 individuals with familial interstitial pneumonia without SFTPC mutations, and 10 individuals with sporadic IPF) and sections from 10 control lungs. After demonstrating UPR activation in cultured A549 cells expressing mutant SFTPC, we identified prominent expression of UPR markers in AECs in the lungs of patients with SFTPC mutation-associated fibrosis. In individuals with familial interstitial pneumonia without SFTPC mutations and patients with sporadic IPF, we also found UPR activation selectively in AECs lining areas of fibrotic remodeling. Because herpesviruses are found frequently in IPF lungs and can induce ER stress, we investigated expression of viral proteins in lung biopsies. Herpesvirus protein expression was found in AECs from 15/23 IPF patients and colocalized with UPR markers in AECs from these patients. ER stress and UPR activation are found in the alveolar epithelium in patients with IPF and could contribute to disease progression. Activation of these pathways may result from altered surfactant protein processing or chronic herpesvirus infection.

Cloning and expression of mouse cytosolic alpha-mannosidase (Man2c1).

It is known that the neutral/cytosolic alpha-mannosidase (Man2c1) which can cleave alpha 1,2-, alpha 1,3-, and alpha 1,6-linked mannose residues, is stimulated by cobalt and is inhibited by furanose analogues swainsonine (SW) and 1,4-dideoxy-1,4-imino-d-mannitol (DIM). The enzyme is involved in the degradation of oligomannosides derived from dolichol intermediates and the degradation of newly synthesized glycoproteins. An immunological relationship has been demonstrated between the rat endoplasmic reticulum alpha-mannosidase and the cytosolic alpha-mannosidase. In fact antibodies raised against the soluble alpha-mannosidase recognized the membrane form of the ER alpha-mannosidase. A cDNA encoding the mouse cytosolic alpha-mannosidase was obtained by RZPD (Deutsches Ressourcenzentrum fur Genomforschung GmbH), Berlin, Germany. Comparison of the mouse genomic sequence with the cDNA sequence revealed the presence of 25 introns within the cytosolic alpha-mannosidase gene. The gene spans 11.5 kb from the major transcription initiation site to the RNA cleavage site. The transcription initiation site of mouse cytosolic alpha-mannosidase was mapped to 170 bases upstream of the ATG codon using 5' RACE. Northern blotting analysis revealed expression of a major transcript of 3.8 kb in all tissues examined. COS cells transfected with the cDNA showed a 20-fold increase in cytosolic alpha-mannosidase activity. This enzyme activity was stimulated by cobalt and inhibited by DIM and EDTA. Furthermore we demonstrated that the expressed enzyme was active towards the radiolabeled substrate Man9GlcNAc1 giving the final product Man5GlcNAc1 through the formation of Man8GlcNAc1 isomer C as intermediate.

[Differential gene expression in nasopharyngeal carcinoma cell with reduced and normal expression of 6A8 alpha-mannosidase].

OBJECTIVE: To detect the differential display of mRNA expression between human nasopharyngeal carcinoma cell CNE-2L2 with reduced malignancy caused by transduction of a DNA antisense to 6A8 alpha-mannosidase cDNA (AS cell) and the wild type cell (W cell). METHODS: Differential display of mRNA expression was analyzed using DNA microarray analysis. The datasets were confirmed by Northern blotting and RT-PCR. RESULTS: Out of the 1069 genes analyzed, 34 genes were up-regulated in AS cells relative to W cells. Conversely, 42 genes were down-regulated. The genes, up-regulation of which might have suppressive effect on tumor malignant behaviors, were P130 mRNA for 130K protein, TGF-betaIIR alpha, GABBR1, TGFBR1, TNFAIP1, STANIN, E-CADHERIN, CTNNA1 and 2, RFX2, TMPO, etc. The genes, down-regulation of which might have suppressive effect on tumor malignant behaviors, were CD44, NDRG1, TGFB1, RPS5, LEGUMAIIN, CBS, CD59, SNRPA1, etc. The microarray datasets were confirmed by Northern blot and RT-PCR analysis. CONCLUSIONS: In comparison to the W cell, AS cell has up-regulation of 34 genes and down-regulation of 42 genes. Changes of the gene expression may play a role in the malignancy reduction of AS cell.

Human endo-alpha1,2-mannosidase is a Golgi-resident type II membrane protein.

The cDNA for human endo-alpha1,2-mannosidase was reconstructed using two independent EST-clones and its properties characterized. The 2837 bp cDNA construct contained a 1389 bp open reading frame (ORF) encoding for 462 amino acids and an approximately 53.6 kDa protein, respectively. Hydrophobicity analysis of this amino acid sequence, as well as proteolytic degradation studies, indicate that the enzyme is a type II protein, anchored in the membrane via a 19 amino-acid long apolar sequence close to the N-terminus. Human endo-alpha1,2-mannosidase displays a high degree of sequence identity with the catalytic domain of the homologous rat liver endo-enzyme, but differs substantially in the N-terminal peptide region, which includes the transmembrane domain. No sequence similarity exists with other processing alpha-glycosidases. Based on sequence information provided by the 2837 bp construct, the cDNA consisting of the complete 1389 bp ORF was amplified by RT-PCR using human fibroblast RNA. Incubation of E. coli lysates with this cDNA, previously modified for boost translation by codon optimization, resulted in the synthesis of an approximately 52 kDa protein which degraded [(14)C]Glc(3)-Man(9)-GlcNAc(2) efficiently, indicating that the catalytic domain of the enzyme folds correctly under cell-free conditions. Transfection of the endo-alpha1,2-mannosidase wild-type cDNA into COS 1 cells resulted in a moderate (approximately 1.5-fold) but reproducible increase of activity compared with control cells, whereas >18-fold increase in activity was measured after expression of a chimera containing green-fluorescent-protein (GFP) attached to the N-terminus of the endo-alpha1,2-mannosidase polypeptide. This, together with the observation that GFP-endo-alpha1,2-mannosidase is expressed as a Golgi-resident type II protein, points to enzyme-specific parameters directing folding and membrane anchoring, as well as Golgi-targeting, not being affected by fusion of GFP to the endo-alpha1,2-mannosidase N-terminus.

Effective gene therapy for an inherited CNS disease in a large animal model.

Genetic diseases affecting the brain typically have widespread lesions that require global correction. Lysosomal storage diseases are good candidates for central nervous system gene therapy, because active enzyme from genetically corrected cells can be secreted and taken up by surrounding diseased cells, and only small amounts of enzyme (<5% of normal) are required to reverse storage lesions. Injection of gene transfer vectors into multiple sites in the mouse brain has been shown to mediate widespread reversal of storage lesions in several disease models. To study a brain closer in size to the human brain, we evaluated the extent of storage correction mediated by a limited number of adeno-associated virus vector injections in the cat model of human alpha-mannosidosis. The treated cats showed remarkable improvements in clinical neurological signs and in brain myelination assessed by quantitative magnetic resonance imaging. Postmortem examination showed that storage lesions were greatly reduced throughout the brain, even though gene transfer was limited to the areas surrounding the injection tracks. The data demonstrate that widespread improvement of neuropathology in a large mammalian brain can be achieved using multiple injection sites during one operation and suggest that this could be an effective treatment for the central nervous system component of human lysosomal enzyme deficiencies.

[Inhibition of 6A8 alpha-manosidase expression induces decrease of adhesion to laminin and reduction of lamellipodia of human nasopharyngeal carcinoma cell CNE-2L2].

OBJECTIVE: To investigate the inhibitory effect of 6A8 alpha-manosidase expression on the adhesiveness of CNE-2L2 cells to laminin and the lamellipodia on cell surface. METHODS: 6A8 alpha-manosidase expression was detected by Western blotting. For assaying the adhesion of cells to laminin, cells were incubated in laminin-coated plate at 37 degrees C for 1 h, the adhered cells were stained with crystal purple dissolved in 0.1 mol/L Sodium Citrate/50% ethanol. Absorbance 540 nm was measured. Adhesion rate (R) was calculated according to formula R = AT/A100 x 100%. Here A100 represents 100% adhesion. lamellipodia on cell surface was observed upon a scanning electron microscopy. RESULTS: The adhesion rate of two clones (AS1 and AS2) with inhibition of 6A8 alpha-manosidase expression to laminin was 0.447 +/- 0.096 and 0.533 +/- 0.065 respectively. The adhesion rate of three controls with normal expression of 6A8 alpha-manosidase to laminin was 0.78 +/- 0.035, 0.7 +/- 0.05 and 0.80 +/- 0.04 respectively. The difference was significant (P < 0.01). CNE-2L2 cells with normal expression of 6A8 alpha-manosidase was rich in lamellipodia on their surface. Lamellipodia nearly disappeared on the cells with inhibition of 6A8 alpha-manosidase expression. CONCLUSIONS: Inhibition of 6A8 alpha-manosidase expression results in decrease of adhesion to laminin and reduction of lamellipodia of human nasopharyngeal carcinoma cell CNE-2L2.

[Molecular mechanism of metastasis inhibition of nasopharyngeal carcinoma cell CNE-2L2 induced by reduction of 6A8 alpha-mannosidase expression].

OBJECTIVE: To study the effect of inhibition of 6A8 alpha-mannosidase expression on adhesiveness among and E-cadherin expression on CNE-2L2 cells, and on metastasis of the tumors from the cells inoculated in nude mice. METHODS: Anchorage-independent adhesion among cells was examined in soft agar culture. E-cadherin expression was studied by immunofluorescence staining, immunohistological staining and RT-PCR. CNE-2L2 cells were subcutaneously inoculated into nude mice. Eight weeks later tumor metastasis was demonstrated by means of histological examination of lung sections. RESULTS: CNE-2L2 cells with suppression of 6A8 alpha-mannosidase expression (AS) became aggregated. E-cadherin expression on wild type cells was very weak. In contrast, it was greatly enhanced on AS cells. The enhancement was detected on both protein and mRNA levels. Lung metastasis of the tumor from inoculated AS cells were heavily inhibited in nude mice. CONCLUSION: Inhibition of 6A8 alpha-mannosidase expression results in enhancement of cell-cell adhesion and of E-cadherin expression on CNE-2L2 cells. Lung metastasis of the tumor grown from AS cell inoculate in nude mice is heavily suppressed.

[Growth inhibition of human nasopharyngeal carcinoma cell CNE-2L2 caused by suppression of 6A8 alpha-mannosidase expression].

OBJECTIVE: To study the relationship between 6A8 alpha-mannosidase expression and growth of CNE-2L2 cells, a human nasopharyngeal carcinoma cell line. METHODS: Recombinant adeno-associated virus vector (rAAV) was used as a mediator to transfer an antisense or a sense fragment of 6A8 cDNA into CNE-2L2 cells. 6A8 alpha-mannosidase expression was detected by means of mAb 6A8a staining, alpha-mannosidase activity assay and ConA binding test. Cell growth was examined by means of MTT and colony formation. Tumor growth at the inoculated site of the cells in nude mice was detected after 8 weeks. RESULTS: Transduction of antisense 6A8 could reduce the expression of 6A8 alpha-mannosidase. In comparison to those in controls, the wild type, the mock-transduced and the sense 6A8-transduced cells, the MTT value, the colony number formed and the tumor weight grown at the inoculated site of cells were significantly decreased in the antisense 6A8-transduced cells (P < 0.001). CONCLUSION: Decreased expression of 6A8 alpha-mannosidase caused an inhibition of CNE-2L2 cell growth.

[6A8 alpha-mannosidase catalyzes p-nitrophenyl-alpha-D-mannopyranoside].

OBJECTIVE: To confirm the alpha-mannosidase nature of the protein encoded by 6A8 cDNA. METHODS: 1) To construct a full-length 6A8 cDNA based on the three cloned DNA fragments by means of gene recombinant technique; 2) To insert the 6A8 cDNA into eukaryotic expression vector pCDI; 3) To transfect the recombinant pCDI-6A8 into COS-7 cells; 4) To characterize the nature of the protein encoded by 6A8 cDNA by means of enzymic activity assay and Western blotting assay. RESULTS: The constructed 6A8 cDNA was the right cDNA in sequence. The enzymetic activity of the homogenate of COS-7 cells transfected with pCDI-6A8 was 3-4 times higher than that of the cells transfected with the mock or the wild cells. The enzymetic reaction could not be inhibited by swainsonine. Western blot showed a band of 120,000 recognized by mAb 6A8. The band in the cells transfected with pCDI-6A8 cDNA was much darker than that in the cells transfected with the mock or in the wild cells. CONCLUSION: The protein encoded by 6A8 cDNA is a kind of alpha-mannosidase, which belongs to type II alpha-mannosidase.

[Effect of 6A8 alpha-mannosidase expression on the proliferative response of human B cell line 3D5].

OBJECTIVE: To study the effect of 6A8 alpha-mannosidase expression on the proliferative response of human B cell 3D5. METHODS: Recombination of adeno-associated virus vector(rAAV) mediated delivery of sense 6A8 DNA or antisense 6A8 DNA into 3D5 cells, and monoclonal antibody 6A8 alpha staining and Con A binding assay for determination of the change of 6A8 alpha-mannosidase expression, MTT assay for proliferation detection of 3D5 cells driven by Staphylococcus aureus crude cell suspension formalin-fixed (SAC), lower molecular weight B cell growth factor (LMW-BCGF), or rIL-6. RESULTS: The expression of 6A8 alpha-mannosidase was enhanced in sense 6A8-transduced cells and reduced in antisense 6A8-transduced cells. In comparison with the wild type and the mock-transduced cells, the proliferative response of the sense 6A8-transduced cells to SAC stimulation was enhanced (P < 0.05). However, transduction with antisense 6A8 did not affect the response. In addition, transduction with either sense or antisense 6A8 had no effect on proliferation of 3D5 cells induced by LMW-BCGF or IL-6. CONCLUSION: The proliferative response to SAC stimulation was enhanced in the 3D5 cells with enhanced expression of 6A8 alpha-mannosidase. Either enhancement or reduction of 6A8 alpha-mannosidase expression had no effect on proliferation induced by LMW-BCGF or IL-6.