Prenatal diagnosis of a trisomy 7 mosaic case: CMA, CNV-seq, karyotyping, interphase FISH, and MS-MLPA, which technique to choose?

OBJECTIVE

This study aims to perform a prenatal genetic diagnosis of a high-risk fetus with trisomy 7 identified by noninvasive prenatal testing (NIPT) and to evaluate the efficacy of different genetic testing techniques for prenatal diagnosis of trisomy mosaicism.

METHODS

For prenatal diagnosis of a pregnant woman with a high risk of trisomy 7 suggested by NIPT, karyotyping and chromosomal microarray analysis (CMA) were performed on an amniotic fluid sample. Low-depth whole-genome copy number variation sequencing (CNV-seq) and fluorescence in situ hybridization (FISH) were used to clarify the results further. In addition, methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) was performed to analyze the possibility of uniparental disomy(UPD).

RESULTS

Amniotic fluid karyotype analysis revealed a 46, XX result. Approximately 20% mosaic trisomy 7 was detected according to the CMA result. About 16% and 4% of mosaicism was detected by CNV-seq and FISH, respectively. MS-MLPA showed no methylation abnormalities. The fetal ultrasound did not show any detectable abnormalities except for mild intrauterine growth retardation seen at 39 weeks of gestation. After receiving genetic counseling, the expectant mother decided to continue the pregnancy, and follow-up within three months of delivery was normal.

CONCLUSION

In high-risk NIPT diagnosis, a combination of cytogenetic and molecular genetic techniques proves fruitful in detecting low-level mosaicism. Furthermore, the exclusion of UPD on chromosome 7 remains crucial when NIPT indicates a positive prenatal diagnosis of trisomy 7.

Prenatal diagnosis, pregnancy determination and follow up of sex chromosome aneuploidy screened by non-invasive prenatal testing from 122 453 unselected singleton pregnancies: A retrospective analysis of 7-year experience

The phenotype of SCA patients are diversities, make prenatal counseling and parental decision-making following the prenatal diagnosis of SCA more complicated and challenging. NIPT has higher sensitivity and specificity in screening trisomy 21 syndrome, but the effectiveness of NIPT in detecting SCA is still controversial. This study is a large-scale retrospective cohort of positive SCA screened from unselected singleton pregnancies by non-invasive prenatal testing (NIPT) from a single prenatal center of a tertiary hospital. Clinical information, indications, diagnostic results, ultrasound findings, pregnancy determinations, and follow-up were reviewed and analyzed. 596 cases of SCA positive were screened out of 122 453, giving a positive detection rate of 0.49%. 510 cases (85.6%) conducted with amniocentesis to detect fetal chromosome, of which 236 were confirmed as true positive of SCA with PPV of 46.3% (236/510). Of the 236 cases confirmed as true positive SCA, 114 cases (48.3%)chose to terminate the pregnancy (93.0%, 65.3%, 15.4% and 10.9% for 45,X, 47,XXY, 47,XXX and 47,XYY, respectively), 122 cases (51.7%) elected to continue the pregnancy. In conclusions, NIPT as a first-tier routine method for screening autosomal aneuploidies, also could play an important role in screening SCA. Low-risk pregnant women are the main indication for the detection of SCA as NIPT test provides to non-selective population. For 47,XXX and 47,XYY with mild phenotype, couples would like to continue the pregnancy. But for 45,X and 47,XXY, parents apt to terminate pregnancy no matter ultrasound abnormalities were found or not.

Claudin-10 Decrease in the Submandibular Gland Contributes to Xerostomia

Tight junction proteins play a crucial role in paracellular transport in salivary gland epithelia. It is clear that severe xerostomia in patients with HELIX syndrome is caused by mutations in the claudin-10 gene. However, little is known about the expression pattern and role of claudin-10 in saliva secretion in physical and disease conditions. In the present study, we found that only claudin-10b transcript was expressed in human and mouse submandibular gland (SMG) tissues, and claudin-10 protein was dominantly distributed at the apicolateral membranes of acini in human, rat, and mouse SMGs. Overexpression of claudin-10 significantly reduced transepithelial electrical resistance and increased paracellular transport of dextran and Na+ in SMG-C6 cells. In C57BL/6 mice, pilocarpine stimulation promoted secretion and cation concentration in saliva in a dose-dependent increase. Assembly of claudin-10 to the most apicolateral portions in acini of SMGs was observed in the lower pilocarpine (1 mg/kg)-treated group, and this phenomenon was much obvious in the higher pilocarpine (10 mg/kg)-treated group. Furthermore, 7-, 14-, and 21-wk-old nonobese diabetic (NOD) and BALB/c mice were used to mimic the progression of hyposalivation in Sjögren syndrome. Intensity of claudin-10 protein was obviously lower in SMGs of 14- and 21-wk-old NOD mice compared with that of age-matched BALB/c mice. In the cultured mouse SMG tissues, interferon-γ (IFN-γ) downregulated claudin-10 expression. In claudin-10-overexpressed SMG-C6 cells, paracellular permeability was decreased. Furthermore, IFN-γ stimulation increased p-STAT1 level, whereas pretreatment with JAK/STAT1 antagonist significantly alleviated the IFN-γ-induced claudin-10 downregulation. These results indicate that claudin-10 functions as a pore-forming component in acinar epithelia of SMGs, assembly of claudin-10 is required for saliva secretion, and downregulation of claudin-10 induces hyposecretion. These findings may provide new clues to novel therapeutic targets on hyposalivation.

The Role of Endothelial Barrier Function in the Fibrosis of Salivary Gland

In the salivary glands, fibrosis occurs in many pathological conditions. Endothelial tight junction (TJ)-based barrier function plays a vital role in maintaining the homeostasis of the salivary glands. However, whether endothelial barrier function is changed and involved in the pathogenesis of glandular fibrosis is unknown. Here, by using a mouse model in which the main excretory duct of the submandibular gland (SMG) was ligated to induce inflammation and fibrosis, endothelial barrier function and TJ protein expression and distribution were examined. Both 4-kDa and 70-kDa fluorescence-labeled dextrans permeated more in the 1-, 3-, and 7-d ligated SMGs. Meanwhile, the mRNA level of claudin-5 was increased with an obvious redistribution from apicolateral membranes to lateral membranes and cytoplasm in the fibrotic glands. Notably, the TJ sealer AT1001 significantly attenuated the disrupted endothelial barrier function and thereby ameliorated the glandular fibrosis. Cytokine array detection showed that monocyte chemoattractant protein-1 (MCP-1) was highly enriched in the 3-d ligated SMGs, and MCP-1 directly impaired barrier function, increased claudin-5 expression, induced the relocalization of claudin-5, and activated p-ERK1/2 in cultured human endothelial cells. Furthermore, the upregulation and disorganization of claudin-5 as well as the elevation of MCP-1 and p-ERK1/2 signaling were also confirmed in fibrotic SMGs from patients with chronic sialadenitis and immunoglobulin G4-related sialadenitis. Altogether, our findings revealed that disrupted endothelial barrier function contributed to the progression of glandular fibrosis, and targeting endothelial TJs might be a promising approach to alleviate salivary gland fibrosis-related diseases.

Advances in physiological mechanisms of selenium to improve heavy metal stress tolerance in plants

Selenium (Se) is a metalloid mineral nutrient for human and animal health. Plants are the main foodstuff source of the Se intake of humans. For plants, the addition of an appropriate amount of Se could promotes growth and development, and improves the tolerance to environmental stress, especially stress from some of heavy metals (HM) stress, such as cadmium (Cd) and mercury (Hg). This paper mainly reviews and summarizes the physiological mechanism of Se in enhancing HM stress tolerance in plants. The antagonistic effect of Se on HM is a comprehensive effect that includes many physiological mechanisms. Se can promote the removal of excessive reactive oxygen species and reduce the oxidative damage of plant cells under HM elements stress. Se participates in the regulation of the transportation and distribution of HM ions in plants, and alleviates the damage caused by of HM stress. Moreover, Se combine with HM elements to form Se-HM complexes and promote the production of phytochelatins (PCs), thereby reducing the accumulation of HM ions in plants. Overall, Se plays an important role in plant response to HM stress, but current studies mainly focus on physiological mechanism, and further in-depth study on the molecular mechanism is essential to confirm the participation of Se in plant response to environmental stress. This review helps to comprehensively understand the physiological mechanism of Se in plant tolerance against to HM stress of plants, and provides important theoretical support for the practical application of Se in environmental remediation and agricultural development.

Behavioral and neuroanatomical outcomes following altered serotonin expression in a hypoxic-ischemic injury neonate rodent model

BACKGROUND

Children born prematurely (<37 gestational weeks) are at risk for a variety of adverse medical events. They may experience ischemic and/or hemorrhagic events leading to negative neural sequelae. They are also exposed to repeated stressful experiences as part of life-saving care within the neonatal intensive care unit (NICU). These experiences have been associated with methylation of SLC6A4, a gene which codes for serotonin transport proteins, and is associated with anxiety, depression, and increased incidence of autism spectrum disorders.The purpose of this study was to examine the effects of altered serotonin levels on behavioral and neuroanatomical outcomes in a neonatal rodent model with or without exposure to hypoxic-ischemic (HI) injury.

METHODS

Wistar rat pups were randomly assigned to either HI injury or sham groups. Pups within each group were treated with a chronic SSRI (Citalopram HBr) to simulate the effects of SLC6A4 methylation, or saline (NS). Subjects were assessed on behavioral tasks and neuropathologic indices.

RESULTS

HI injured subjects performed poorly on behavioral tasks. SSRI subjects did not display significantly greater anxiety. HI + SSRI subjects learned faster than HI+NS. Histologically, SSRI subjects had predominantly larger brain volumes than NS.

CONCLUSION

SSRI treated subjects without injury showed patterns of increased anxiety, consistent with theories of SLC6A4 methylation. The paradoxical trend to improved cognition in HI+SSRI subjects relative to HI alone, may reflect an unexpected SSRI neuroprotective effect in the presence of injury, and may be related to serotonin-induced neurogenesis.

Tricellulin Modulates Transport of Macromolecules in the Salivary Gland

Volume and composition of saliva are crucial for oral and systemic health. How substances, particularly macromolecules, are transported across the salivary gland epithelium has not been established in detail. Tricellulin is a component of tricellular tight junctions that form a central tube to serve as an important route for macromolecule transport. Whether tricellulin is expressed in the submandibular gland (SMG) and involved in salivation has been unknown. Here, by using Western blotting and immunofluorescence, tricellulin was found to be characteristically localized at tricellular contacts of human, rat, and mouse SMGs. Knockdown of tricellulin significantly increased, whereas overexpression of tricellulin decreased, paracellular permeability for 40-kDa but not for 4-kDa fluorescein isothiocyanate–dextran, while transepithelial electrical resistance was unaffected. Conversely, claudin-4 knockdown and overexpression affected transepithelial electrical resistance but not 40-kDa fluorescein isothiocyanate–dextran transport, suggesting that tricellulin regulated transport of macromolecules but not ions, which were mainly regulated by bicellular tight junctions (bTJs). Moreover, tricellulin was dynamically redistributed from tri- to bicellular membranes in cholinergically stimulated SMG tissues and cells. Immunoglobulin-like domain-containing receptor 1 (ILDR1) recruits tricellulin to tricellular contacts. The proportion of macromolecules in the saliva was increased, whereas the amount of stimulated saliva was unchanged in Ildr1-/- mice, which displayed abnormal tricellulin distribution in SMGs. Furthermore, tricellulin interacted with bTJ proteins, such as occludin, claudin-1, claudin-3, claudin-4, and ZO-1, in rat SMG epithelial polarized cell line SMG-C6. Knockdown of tricellulin decreased occludin levels. Thus, we revealed a specific expression pattern of tricellulin in SMG epithelium. Tricellulin not only functioned as a barrier for macromolecules but also modulated the connection of bTJs to the tight junction complex. Alterations in tricellulin expression and distribution could thereby change salivary composition. Our study provided novel insights on salivary gland tight junction organization and function.

[Role and mechanism of muscarinic acetylcholine receptor in the regulation of submandibular gland secretion]

Muscarinic acetylcholine receptors (mAChRs), including M1-M5 subtypes, are classic receptors in regulating water, ion, and solute transport in salivary gland. Our work focuses on the studies on the expression pattern and function of mAChR in the submandibular gland (SMG), and the underlying mechanism involved in the mAChR-regulated secretion, together with the effect of parasympathectomy on the salivary secretion. Microvascular autotransplantation of SMG into the temporal fossa provides a continuous and endogenous source of fluids, and is currently an effective method for treating severe keratoconjunctivitis sicca. By using RT-PCR, Western blotting, and immunofluorescence, our data demonstrated that the expression of M1 and M3 subtypes were decreased in latent period in rabbit SMG autotransplantation model, whereas carbachol stimulation promoted the salivary secretion, as well as M1 and M3 expressions. By contrast, mAChRs were hypersensitive in epiphora SMGs, whereas atropine gel and botulinum toxin A application significantly inhibited the hypersecretion in both animal models and patients. Furthermore, the possible intracellular signal molecules involved in the mAChR-modulated salivary secretion were explored. Activation of mAChR upregulated the expression of aquaporin 5 (AQP5), the main transporter that mediated water secretion through transcellular pathway, and led to AQP5 trafficking from lipid rafts to non-lipid microdomain. Extracellular signal-regulated kinase 1/2 (ERK1/2) was involved in the mAChR-regulated AQP5 content. mAChR activation also modulated the expression, distribution, and function of tight junction proteins, and increased paracellular permeability. ERK1/2/β-arrestin2/clathrin/ubiquitin signaling pathway was responsible for the mAChR-regulated downregulation of tight junction molecule claudin-4. Cytoskeleton filamentous actin (F-actin) was also involved in the distribution and barrier function of epithelial tight junctions. Besides, endothelial tight junctions were opened by mAChR agonist-evoked salivation in the mice. Furthermore, parasympathetic denervation increased resting salivary secretion in the long terminrats and minipigs. Taken together, our work demonstrated that mAChR regulated saliva secretion via transcellular and paracellular pathways in SMG epithelium as well as tight junction opening in SMG endothelium. Modulation of mAChR might be a promising strategy to ameliorate SMG dysfunction.

Rapid specific and visible detection of porcine circovirus type 3 using loop-mediated isothermal amplification (LAMP)

In this study, a rapid and specific assay for the detection of porcine circovirus type 3 (PCV3) was established using loop-mediated isothermal amplification (LAMP). Four primers were specifically designed to amplify PCV3. The LAMP assay was effectively optimized to amplify PCV3 by water bath at 60°C for 60 min. The detection limit was approximately 1 × 10¹ copy in this LAMP assay. Compared to porcine circovirus type 2 (PCV2), both gE and gD genes of pseudorabies virus (PRV) and porcine parvovirus (PPV), the LAMP assay showed a high specific detection of PCV3. A visible detection method was developed using SYBR Green I to recognize the results rapidly. Based on the detection of 20 clinical tissue samples, the LAMP assay was more practical and convenient than classical PCR due to its simplicity, high sensitivity, rapidity, specificity, visibility and cost efficiency.

[A 20-year study on microvascular autologous transplantation of submandibular gland for treatment of severe dry eye]

Severe dry eye is a refractory ophthalmologic disease. Our multidisciplinary research group treated severe dry eye by microvascular autologous transplantation of submandibular gland (SMG) during the past 20 years. The SMG, with its blood vessels and Wharton's duct, was harvested from the submandibular triangle and transferred to the temporal area. The blood vessels in the SMG were anastomosed with the temporal blood vessels using a microsurgical technique. Then, the distal end of Wharton's duct was sutured to form an opening in the upper lateral conjunctival fold. The tear was replaced by the secretion of the transplanted SMG to lubricate the ocular surface. In our study, the surgical techniques of blood vessel management were continuously modified to increase the survival rate of the transplanted SMG. A novel surgical modality of partial transplantation of SMG was established to prevent postoperative epiphora. A clinical study with the largest case number in the world was conducted and the effectiveness of transplantation of SMG for severe dry eye was fully confirmed. In order to resolve two main clinical problems including ductal obstruction resulted from low secretion rate during the latent period, and epiphora due to over secretion of the transplanted SMG in the later term of transplantation, the regulation of the secretion mechanism of the normal and transplanted SMG were investigated. New opinions on mechanisms of saliva secretion were provided. Based on the priniciple of translational medicine, the results of related basic research were applied in the clinic. The clinical guidelines for secretion regulation of transplanted SMG were established. A concept of chronic obstructive sialadenitis of transplanted SMG was provided and its diagnostic criteria, diagnostic technique of sialography, and therapeutic regimen were established. As a result, the surgical success rate was obviously elevated, the surgical complications were decreased, and life quality of the patients was greatly improved.

Presence of Torque teno sus virus 1 and 2 in porcine circovirus 3-positive pigs

In this study, the co-infection of Torque teno sus virus (TTSuV) and porcine circovirus type 3 (PCV3) was reported. One hundred and ten of 132 (83.3%) PCV3-positive samples were co-infected with Torque teno sus virus 1 (TTSuV1). Ninety-four of 132 (71.2%) PCV3-positive samples were co-infected with Torque teno sus virus 2 (TTSuV2). Sixty-six of 132 (50.0%) of PCV3-positive samples were co-infected with both TTSuV1 and TTSuV2. There were no clinical signs of infection in pigs that were both PCV3-positive and PCV2-negative, in either multiparous sows or live-born infants. The high co-infection rate provides valuable information for the further study of the pathological correlation between PCV3 and TTSuVs.

Endothelial Tight Junctions Are Opened in Cholinergic-Evoked Salivation In Vivo

Blood vessels provide the original supplies for the formation of primary saliva, which is regulated by the tight junctions (TJs) between endothelial cells. Previous studies have shown that blood flow increases with vasodilatation during cholinergic-evoked salivation. However, changes in vascular paracellular permeability and the role of endothelial TJs in salivation are unknown. Here, we established an in vivo paracellular permeability detection system and observed that the endothelial TJs were permeable to 4-kDa fluorescein isothiocyanate (FITC)-dextran while impermeable to 40- and 70-kDa FITC-dextran under an unstimulated condition in mouse submandibular glands (SMGs). Pilocarpine increased the flux of 4- and 40-kDa FITC-dextran out of blood vessels but did not affect 70-kDa FITC-dextran. Claudin 5, a TJ protein specifically localized in salivary endothelial cells, was redistributed from the apicolateral membranes to the lateral and basolateral membranes and cytoplasm in cholinergic-stimulated mouse SMGs and freshly cultured human SMG tissues. In the transplanted SMGs from epiphora patients, we found that claudin 5 was present in the basolateral membranes and cytoplasm, instead of the apical region in control SMGs. Moreover, the level of phospho-myosin light chain 2 increased within the blood vessels of the pilocarpine-stimulated mouse SMGs and transplanted human SMGs, while the downstream molecule F-actin was reorganized in the endothelial cells of the transplanted human SMGs. Taken together, our findings provide direct visual evidence that the opening of endothelial TJs and the redistribution of claudin 5 are essential events contributing to cholinergic-evoked salivation, thus enriching our understanding of the secretory mechanisms that link blood flow to primary saliva formation by regulating the endothelial paracellular permeability.

Interleukin-17 Impairs Salivary Tight Junction Integrity in Sjögren's Syndrome

Sjögren's syndrome (SS) is an inflammatory autoimmune disease that causes secretory dysfunction of the salivary glands. It has been reported that proinflammatory cytokine interleukin-17 (IL-17) was elevated and tight junction (TJ) integrity disrupted in minor salivary glands from SS patients. However, whether the elevated IL-17 in SS affects TJ integrity and thereby alters the function of salivary gland is unknown. Here, by using nonobese diabetic (NOD) mice as SS model, we found that the stimulated salivary flow rate was significantly decreased in NOD mice. Lymphocyte infiltration was mainly observed in submandibular glands (SMGs), but not parotid glands (PGs), of NOD mice. IL-17 was significantly increased and mainly located in lymphocytic-infiltrating regions in SMGs but not detectable in PGs of NOD mice. Meanwhile, the epithelial barrier function was disrupted, as evidenced by an increased paracellular tracer clearance and an enlarged acinar TJ width in SMGs of NOD mice. Furthermore, claudin-1 and -3 were elevated especially at the basolateral membranes, whereas claudin-4, occludin, and zonula occludens-1 (ZO-1) were reduced in SMGs of NOD mice. Moreover, occludin and ZO-1 were dispersed into cytoplasm in SMGs of NOD mice. However, no change in the expression and distribution of TJ proteins was found in PGs. In vitro, IL-17 significantly decreased the levels and apical staining of claudin-4 and ZO-1 proteins in the cultured SMG tissues, as well as claudin-1, occludin, and ZO-1 in PG tissues. Moreover, IL-17 activated the phosphorylation of IκBα and p65 in SMG cells, whereas pretreatment with NF-κB inhibitor pyrrolidine dithiocarbamate suppressed the IL-17-induced downregulation of claudin-4 and ZO-1 in SMG tissues. Taken together, these findings indicate that IL-17 derived from infiltrating lymphocyte impairs the integrity of TJ barrier through NF-κB signaling pathway, and thus might contribute to salivary gland dysfunction in SS.

ZO-1 and -2 Are Required for TRPV1-Modulated Paracellular Permeability

The tight junction–based paracellular pathway plays an important role in saliva secretion. Zonula occludens (ZO) proteins are submembranous proteins of tight junction complex; however, their function in salivary epithelium is poorly understood. Here, we found that activation of transient receptor potential vanilloid subtype 1 (TRPV1) by capsaicin increased rat saliva secretion both in vivo and ex vivo. Meanwhile, TRPV1 activation enlarged the width of tight junctions between neighboring acinar cells, increased the paracellular flux of 4-kDa fluorescein isothiocyanate (FITC)-dextran in submandibular gland (SMG) tissues, and decreased transepithelial electric resistance (TER) in SMG-C6 cells. ZO-1, -2, and -3 were distributed principally to the apical lateral region of acinar cells in SMG tissues and continuously encircled the peripheries of SMG-C6 cells in the untreated condition. TRPV1 activation obviously diminished ZO-1 and -2 staining, but not ZO-3 or β-catenin, at the cell-cell contacts ex vivo and in vitro. Moreover, in untreated SMG-C6 cells, ZO-1 and -2 single or double knockdown by small interfering RNA (siRNA) increased the paracellular flux of 4-kDa FITC-dextran. In capsaicin-treated cells, ZO-1 and -2 single or double knockdown abolished, whereas their re-expression restored, the capsaicin-induced increase in paracellular permeability. Furthermore, TRPV1 activation increased RhoA activity, and inhibition of either RhoA or Rho kinase (ROCK) abolished the capsaicin-induced TER decrease as well as ZO-1 and -2 redistribution. These results indicate that ZO-1 and -2 play crucial roles in both basal salivary epithelial barrier function and TRPV1-modulated paracellular transport. RhoA-ROCK signaling pathway is responsible for TRPV1-modulated paracellular permeability as well as ZO-1 and -2 redistribution.

Pre- and Post-synaptic Effects of Botulinum Toxin A on Submandibular Glands

Intraglandular injection of botulinum toxin type A (BoNT/A) is an effective treatment for sialorrhea. Despite numerous experimental and clinical studies on inhibition of saliva section by BoNT/A, the proteolysis of synaptosomal-associated protein 25 (SNAP-25) following BoNT/A treatment has not yet been confirmed in the salivary gland after injection of BoNT/A. More important, it is not known whether BoNT/A exerts a direct effect in acinar cells. Here, we show that injection of BoNT/A into the rat submandibular gland (SMG) decreased salivary flow in a dose-dependent manner; the inhibitory effect lasted at least 4 wk, and salivary flow recovered to normal levels by 12 wk. During the inhibitory period, SMG neurons and synapses expressed lower levels of full-length SNAP-25, and cleavage of SNAP-25 was observed, as indicated by detection of reduced molecular weight SNAP-25 using Western blotting. In addition, the water channel aquaporin 5 (AQP5) was downregulated and abnormally distributed in rat SMG after injection of BoNT/A. The direct effects of BoNT/A on AQP5 expression and distribution were assessed in vitro to exclude the influence of BoNT/A-induced inhibitory neurotransmission. In stable GFP-AQP5-transfected SMG-C6 cells, treatment with BoNT/A reduced the cell surface protein level of AQP5 in a dose- and time-dependent manner without affecting total AQP5 protein expression. Cell surface biotinylation and immunofluorescence demonstrated translocation of AQP5 from the membrane to the cytoplasm, which was confirmed by decreased levels of AQP5 protein in the membrane fraction and increased levels in the cytoplasmic fraction, suggestive of AQP5 redistribution. Taken together, these results indicated that BoNT/A reversibly decreased saliva secretion in rat SMGs through not only the presynaptic SNAP-25 cleavage but also the postsynaptic AQP5 redistribution. These data provide the first evidence for a direct effect of BoNT/A on the salivary gland.

In vitro and in vivo anticancer effects of mevalonate pathway modulation on human cancer cells

Background:

The increasing usage of statins (the 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors) has revealed a number of unexpected beneficial effects, including a reduction in cancer risk.

Methods:

We investigated the direct anticancer effects of different statins approved for clinical use on human breast and brain cancer cells. We also explored the effects of statins on cancer cells using in silico simulations.

Results:

In vitro studies showed that cerivastatin, pitavastatin, and fluvastatin were the most potent anti-proliferative, autophagy inducing agents in human cancer cells including stem cell-like primary glioblastoma cell lines. Consistently, pitavastatin was more effective than fluvastatin in inhibiting U87 tumour growth in vivo. Intraperitoneal injection was much better than oral administration in delaying glioblastoma growth. Following statin treatment, tumour cells were rescued by adding mevalonate and geranylgeranyl pyrophosphate. Knockdown of geranylgeranyl pyrophosphate synthetase-1 also induced strong cell autophagy and cell death in vitro and reduced U87 tumour growth in vivo. These data demonstrate that statins main effect is via targeting the mevalonate synthesis pathway in tumour cells.

Conclusions:

Our study demonstrates the potent anticancer effects of statins. These safe and well-tolerated drugs need to be further investigated as cancer chemotherapeutics in comprehensive clinical studies.

The C-1021T polymorphism of dopamine β-hydroxylase is not associated with orthostatic hypotension in a Chinese population

To explore the association between the dopamine β-hydroxylase (DBH) gene C-1021T polymorphism and the occurrence of orthostatic hypotension (OH) in Chinese patients, the DBH C-1021T polymorphism was genotyped in 317 patients with OH and 664 age- and sex-matched controls with orthostatic normotension. All subjects underwent an upright posture study for the measurement of orthostatic blood pressure. OH was defined as a drop in blood pressure of 20/10 mm Hg or more within 3 min of assuming the upright posture. The allele frequency of the DBH C-1021T polymorphism in the orthostatic hypotensive group was similar to the orthostatic normotensive group (17.4 versus 14.9%, P>0.05). No statistical significant association was found between the distribution of the C-1021T genotypes and the risk of OH in both the orthostatic hypotensive and orthostatic normotensive groups even after adjustment for demographic parameters. Among the three different genotypes, blood pressure levels did not significantly differ in the general population in this study. The changes in orthostatic systolic or diastolic blood pressures among the different genotype groups were not detected (all P>0.05). The C-1021T polymorphism of the DBH was not associated with orthostatic hypotensive risk in a Chinese population.

Hypersensitive mAChRs are involved in the epiphora of transplanted glands

Autologous transplantation of the submandibular gland is an effective treatment for severe dry eye syndrome. However, more than 40% of patients experience epiphora 3 to 6 months after transplantation. The underlying mechanism of epiphora remains to be elucidated. To investigate the potential roles of muscarinic acetylcholine receptors (mAChRs) in the induction of epiphora in transplanted glands, we assessed and found elevated mRNA and protein expression of M1- and M3-mAChR in transplanted glands from epiphora patients. The content of inositol 1, 4, 5-trisphosphate was also elevated. Moreover, carbachol (5 and 10 µM) induced greater increase of [Ca(2+)]i in isolated epiphora submandibular cells than in controls. Although aquaporin-5 (AQP5) content and distribution in the apical and lateral plasma of epiphora glands did not change, AQP5 content was reduced in lipid microdomains (lipid rafts and caveolae) but increased in non-lipid microdomains compared with controls. Carbachol (10 µM) increased the ratio of non-lipid microdomain to total AQP5 in the cultured control submandibular gland tissue. Taken together, these results indicated that hypersensitive mAChRs might be involved in the epiphora of transplanted submandibular glands by modulating AQP5 trafficking.

Decreased submandibular adiponectin is involved in the progression of autoimmune sialoadenitis in non-obese diabetic mice

OBJECTIVE

To investigate a possible role of adiponectin in the pathogenesis of autoimmune sialoadenitis in non-obese diabetic (NOD) mouse model of Sjögren's syndrome.

MATERIALS AND METHODS

Expression of adiponectin and its receptors (AdipoR1/2) was detected by PCR, immunoblotting, or immunofluorescence. The level of adiponectin was quantified by ELISA. Adiponectin-related signaling molecules and pro-inflammatory cytokines were examined by PCR or immunoblotting. Apoptosis was evaluated by TUNEL staining, flow cytometry, and caspase 3 activation.

RESULTS

Adiponectin and AdipoR1/2 mRNA and protein were expressed in submandibular glands. Adiponectin immunostaining was widely diffused in the cytoplasm of acinar and ductal cells. AdipoR1 was mainly distributed in acinar cytoplasm, while AdipoR2 was predominantly located at acinar cell membrane. Submandibular adiponectin levels were reduced during the progression of autoimmune sialoadenitis in 7-, 14-, and 21-week-old NOD mice, while AdipoR1/2 levels were unchanged. The levels of phosphorylated adenosine monophosphate-activated protein kinase, extracellular signal-regulated kinase 1/2, and p38 mitogen-activated protein kinase were decreased, while interferon (IFN)-γ and glandular apoptosis were temporally increased at all time points. Moreover, exogenous adiponectin supplement inhibited, whereas neutralizing endogenous adiponectin by its antibody promoted IFN-γ-induced apoptosis and caspase 3 activation in cultured submandibular acinar cells.

CONCLUSIONS

Adiponectin plays a protective role on submandibular cells. Decreased adiponectin might promote glandular destruction in autoimmune sialoadenitis.

Regulation of circadian locomotor rhythm by neuropeptide Y-like system in Drosophila melanogaster

Circadian rhythms in behaviour and physiology exist widely in animals, plants, fungi and cyanobacteria. Although much work has been carried out to characterize the endogenous clock circuit, the output signals coupling the circadian pacemaker to behaviour and physiology remain elusive. Here, we show that neuropeptide F (NPF), a homologue of mammalian neuropeptide Y, and its G protein-coupled receptor NPFR1 regulate the locomotor rhythm in Drosophila melanogaster. Flies with loss of function in NPF or NPFR1 were unable to ramp up their activity before lights off under light : dark (LD) cycles, and oscillations in npf/NPF and npfr1/NPFR1 were found to correlate temporally with the locomotor rhythm. Furthermore, NPF is expressed in clock neurones including dorsolateral neurones (LNd s) and ventrolateral neurones (LNv s), whereas NPFR1 is expressed in dorsal neurone 1 (DN1) and LNd s. These results show that NPF signalling is involved in the circadian locomotor rhythm in LD cycles.

Neuropsychiatric symptoms, seizure severity, employment, and quality of life of Jordanians with epilepsy

RATIONALE

Depression and anxiety are more strongly associated with quality of life (QOL) than seizure frequency in several populations with epilepsy. However, QOL is culturally determined and may be influenced by cultural values and norms as well as local policies and resources. The goal of this study is to investigate the impact of neuropsychiatric symptoms and seizure severity on QOL and employment in people with epilepsy living in Jordan.

METHODS

Seizure severity and complications, antiepileptic drug side effects, social stigma, neuropsychiatric symptoms, and mental health (MH-SF36) and physical health (PH-SF36) domains of QOL were assessed in 45 adult patients with epilepsy in a university neurology clinic. Multivariate regression analysis was used to evaluate the relationship between these variables and the quality of life of Jordanians with epilepsy.

RESULTS

Neuropsychiatric symptoms, seizure frequency, and history of injury due to seizure were associated with the MH-SF36. However, earlier age of seizure onset, longer duration of epilepsy, unemployment, and history of chronic disease was associated with lower PH-SF36 scores. Furthermore, there were no differences in QOL, neuropsychiatric symptoms, and seizure frequency in Jordanians who were employed versus unemployed in this study.

CONCLUSIONS

Neuropsychiatric symptoms were significantly associated with mental health-related QOL measures, but not with physically-related QOL measures, in Jordanians with epilepsy. For studies across populations, it is critical to separate mental health from physical health QOL measures. Furthermore, regional differences in culture and policy may more strongly influence employment status than individuals' experiences of epilepsy, neuropsychiatric symptoms, or QOL in some populations.

Long-term association between seizure outcome and depression after resective epilepsy surgery

OBJECTIVE

This study explored the association between long-term epilepsy surgery outcome and changes in depressive symptoms.

METHODS

Adults were enrolled between 1996 and 2001 in a multicenter prospective study to evaluate outcomes of resective epilepsy surgery. The extent of depressive symptoms and depression case status (none, mild, or moderate/severe) were assessed using the Beck Depression Inventory (BDI) preoperatively and 3, 12, 24, 48, and 60 months postoperatively. A mixed-model repeated-measures analysis was performed, adjusting for covariates of seizure location, gender, age, race, education, and seizure control.

RESULTS

Of the total 373 subjects, 256 were evaluated at baseline and 5 years after surgery. At baseline, 164 (64.1%) were not depressed, 34 (13.3%) were mildly depressed, and 58 (22.7%) had moderate to severe depression. After 5 years, 198 (77.3%) were not depressed, 20 (7.8%) were mildly depressed, and 38 (14.8%) were moderately to severely depressed. Five years after surgery, the reduction in mean change from baseline in BDI score was greater in subjects with excellent seizure control than in the fair and poor seizure control groups (p = 0.0006 and p = 0.02 respectively). Those with good seizure control had a greater reduction in BDI score than the poor seizure control group (p = 0.02) and borderline significant reduction compared with the fair seizure control group (p = 0.055).

CONCLUSION

Although study participants had initial improvement in depressive symptoms, on average, after resective surgery, only patients with good or excellent seizure control had sustained long-term improvement in mood.

Activation of transient receptor potential vanilloid subtype 1 increases secretion of the hypofunctional, transplanted submandibular gland

Hyposecretion occurs in most patients early after submandibular gland autotransplantation for severe keratoconjunctivitis sicca. Endogenous transient receptor potential vanilloid subtype 1 (TRPV1) has been recently demonstrated in rabbit submandibular glands, and activation of TRPV1 by capsaicin increases secretion in isolated glands, but the TRPV1-mediated secretory mechanism remains to be elucidated. The purpose of this study was to verify whether activation of TRPV1 by capsaicin could improve the secretion of transplanted gland and its underlying mechanism. The salivary flow of the transplanted glands was significantly decreased, and the mRNA and protein levels of TRPV1 and aquaporin 5 (AQP5) were downregulated in the transplanted glands. Topical capsaicin cream increased secretion and upregulated levels of TRPV1 and AQP5 in transplanted glands. Moreover, in cultured submandibular gland cells, capsaicin increased the mRNA expression of AQP5 and led to redistribution of AQP5 from the cytoplasm to the plasma membrane via TRPV1 activation. Capsaicin enhanced the phosphorylation of extracellular signal-regulated kinase (ERK). Preincubation of cells with PD98059, an inhibitor of ERK kinase, suppressed the capsaicin-induced mRNA expression of AQP5. In summary, the capsaicin-induced secretory mechanism involved activation of TRPV1 and upregulation of AQP5 in an ERK-dependent manner and promoted the redistribution of AQP5 in submandibular gland cells. Activation of TRPV1 may provide a new therapeutic strategy to improve submandibular gland hypofunction.

Aspirin induces apoptosis in mesenchymal stem cells requiring Wnt/beta-catenin pathway

BACKGROUND AND OBJECTIVES

Mesenchymal stem cells (MSC) are multipotent progenitor cells that are have found use in regenerative medicine. We have previously observed that aspirin, a widely used anti-inflammatory drug, inhibits MSC proliferation. Here we have aimed to elucidate whether aspirin induces MSC apoptosis and whether this is modulated through the Wnt/beta-catenin pathway.

MATERIALS AND METHODS

Apoptosis of MSCs was assessed using Hoechst 33342 dye and an Annexin V-FITC/PI Apoptosis Kit. Expression of protein and protein phosphorylation were investigated using Western blot analysis. Caspase-3 activity was detected by applying a caspase-3/CPP32 Colorimetric Assay Kit.

RESULTS

In these MSCs, aspirin induced morphological changes characteristic of apoptosis, cytochrome c release from mitochondria, and caspase-3 activation. Stimulating the Wnt/beta-catenin pathway by both Wnt 3a and GSK-3beta inhibitors (LiCl and SB 216763), blocked aspirin-induced apoptosis and protected mitochondrial function, as demonstrated by decreased cytochrome c release and caspase-3 activity. Aspirin initially caused a time-dependent decrease in COX-2 expression but subsequently, and unexpectedly, elevated the latter. Stimulation of COX-2 expression by aspirin was further enhanced following stimulation of the Wnt/beta-catenin pathway. Application of the COX-2 inhibitor NS-398 suppressed elevated COX-2 expression and promoted aspirin-induced apoptosis.

CONCLUSION

These results demonstrate that the Wnt/beta-catenin pathway is a key modulator of aspirin-induced apoptosis in MSCs by regulation of mitochrondrial/caspase-3 function. More importantly, our findings suggest that aspirin may influence MSC survival under certain conditions; therefore, it should be used with caution when considering regenerative MSC transplantation in patients with concomitant chronic inflammatory diseases such as arthritis.

Isoproterenol improves secretion of transplanted submandibular glands

Autotransplantation of the submandibular gland is effective for severe keratoconjunctivitis sicca. However, most transplants show decreased secretion shortly after the operation, which leads to obstruction of Wharton's duct. The hypothesis that decreased catecholamine release due to denervation contributes to hypofunction in the early phase was tested in transplanted glands in rabbits. We found that salivary flow, expression of beta(1)- and beta(2)-adrenoceptor, and the maximum binding capacity were markedly decreased in the transplanted glands. Isoproterenol significantly reversed the decreased secretion, enhanced the expressions of beta(1)- and beta(2)-adrenoceptor, and ameliorated the atrophy of acinar cells. The contents of cAMP and phospho-ERK 1/2 were increased after isoproterenol treatment. These results indicate that lack of beta-adrenoceptor stimulation is involved in early dysfunction of the transplanted gland. Isoproterenol treatment moderates structural injury and improves secretory function in the transplanted submandibular gland through up-regulating beta(1)- and beta(2)-adrenoceptor expression and post-receptor signal transduction.

Differentiation of hematopoietic stem cells into hepatocytes in liver fibrosis in rats

It has been reported that hematopoietic stem cells (HSC) can differentiate into hepatocytes in the normal liver and in some pathologic environments. The aim of this study was to investigate whether HSC can differentiate into hepatocytes in cases of established liver fibrosis. Rat liver fibrosis was induced by subcutaneous injection of tetrachloride (CCl4). Thy+ CD3- CD45RA- HSC in bone marrow cells, which had been enriched by fluorescence-activated cell sorting (FACS), were labeled with PKH26-GL, and autologously transplanted into CCl4-treated rats. The expressions of albumin (Alb), cytokeratin 8 (CK8), and alpha-smooth muscle actin (SMA) were determined by immunofluorescence methods. The PKH26-GL labeled Thy+ CD3- CD45RA- HSC expressed the hepatocyte-specific markers Alb and CK8, but did not express alpha-SMA in liver fibrosis. Thy+ CD3- CD45RA- HSC differentiated into hepatocytes, but not into hepatic stellate cells. In conclusion, autologous stem cell transplantation may be helpful to treat hepatic fibrosis.

Hematopoietic stem cell mobilization after rat partial orthotopic liver transplantation

BACKGROUND

On the basis of the recently recognized potential of hematopoietic stem cells (HSC) to give rise to hepatocytes, we investigated the possibility that HSC could be mobilized and home to the injured liver promoting tissue repair after 50% partial orthotopic liver transplantation (PLTx) in the rat.

METHODS

Using sex-mismatched (female to male) syngeneic SD rats, we performed 50% PLTx or whole orthotopic liver transplantation (WLTx) versus 50% partial hepatectomy (PHx) and sham operation (O). Elements with stem cell markers were detected in peripheral blood (PB) and in the liver. Liver injury and regeneration were estimated. The sex-determining region for Y chromosome gene (SRY) was used to define cell origin by in situ hybridization in liver sections.

RESULTS

Comparison of WLTx and PHx groups showed a lower survival rate (50%), in the PLTx group were (P<.05). Further, the liver injury was more serious and the levels of serum biochemical parameters were higher. Compared with PHx groups, on days 3 and 5 postoperatively, the mitosis index and the expression of PCNA were lower among the PLTx groups. Compared with WLTx and sham operation groups, beta2m-/Thy-1.1+, CD34+ cells in PB in PLTx groups and PHx were increased on day 1 postoperatively and decreased on the following days. Compared with PHx groups, beta2m-/Thy-1.1+, CD34+ cells were higher in PLTx. The CD34-, c-kit-, and Thy-1.1-positive cells detected in portal tract areas peaked during 3 to 5 days postoperatively in PLTx. Few SRY+ cells were detected in PLTx liver grafts.

CONCLUSIONS

beta2m-/Thy-1.1+ and CD34+ stem cells mobilized after PLTx and PHx may be related to the reduced-size liver. Few HSC are involved in liver regeneration in PLTx.

Flow field and oscillatory shear stress in a tuning-fork-shaped model of the average human carotid bifurcation

The oscillatory shear index (OSI) was developed based on the hypothesis that intimal hyperplasia was correlated with oscillatory shear stresses. However, the validity of the OSI was in question since the correlation between intimal thickness and the OSI at the side walls of the sinus in the Y-shaped model of the average human carotid bifurcation (Y-AHCB) was weak. The objectives of this paper are to examine whether the reason for the weak correlation lies in the deviation in geometry of Y-AHCB from real human carotid bifurcation, and whether this correlation is clearly improved in the tuning-fork-shaped model of the average human carotid bifurcation (TF-AHCB). The geometry of the TF-AHCB model was based on observation and statistical analysis of specimens from 74 cadavers. The flow fields in both models were studied and compared by using flow visualization methods under steady flow conditions and by using laser Doppler anemometer (LDA) under pulsatile flow conditions. The TF-shaped geometry leads to a more complex flow field than the Y-shaped geometry. This added complexity includes strengthened helical movements in the sinus, new flow separation zone, and directional changes in the secondary flow patterns. The results show that the OSI-values at the side walls of the sinus in the TF-shaped model were more than two times as large as those in the Y-shaped model. This study confirmed the stronger correlation between the OSI and intimal thickness in the tuning-fork geometry of human carotid bifurcation, and the TF-AHCB model is a significant improvement over the traditional Y-shaped model.

Expression of the MAGE-1 gene in human hepatocellular carcinomas

OBJECTIVE

To further investigate the expression of MAGE-1 gene in hepatocellular carcinoma (HCC).

METHODS

The tumors and adjacent liver tissue from 45 HCC patients and liver tissue from 28 non-HCC patients (16 with liver cirrhosis and 12 with normal liver) were characterized by RT-PCR. A 421 bp PCR product from a cDNA fragment spanning exons 1, 2 and 3 was sequenced. The HLA type was assayed by standard ELISA in 43 HCC patients.

RESULTS

Thirty-two of 45 tumor tissues from HCC patients expressed MAGE-1 mRNA (71.1%). In contrast, MAGE-1 mRNA was not detected in adjacent tissues. Three were found to have point mutations at 3 identical sites resulting in the substitution of two amino acid residues. The most frequent HLA types in 43 HCC patients were: HLA-A2, 53.5%; A11, 25.6%; A24, 20.9%; A33, 20.9%; HLA-B13, 28.3% and B35, 23.2%. Expression of HLA-A33 (20.9%) was higher in HCC patients than that predicted in the normal Chinese population (8.8%). There was no discemable correlation between MAGE-1 expression and alpha-FP level, tumor size and hepatitis B or C virus infection. The identification of peptides which are restricted by haploptypes other than A1 should increase the opportunity for peptide based immunotherapy.

CONCLUSIONS

This study shows that MAGE-1 mRNA is highly expressed in HCC tumor tissue in Chinese patients. Previously unreported point mutations in the MAGE-1 gene are described and may also provide additional opportunities for immunotherapy.

[Application of microsatellite alteration of urine sediment in the early diagnosis of bladder cancer]

OBJECTIVE

To assess the usefulness of microsatellite DNA sequence (MS) alterations in urine sediment for early diagnosis of human bladder cancer.

METHODS

Loss of heterozygosity(LOH) and microsatellite instability(MIN) in urine sediment from 28 cases of bladder cancer were detected by polymerase chain reaction (PCR) with selected primers of 10 microsatellite loci. The peripheral blood mononuclear cells and bladder carcinoma cells were used as controls.

RESULTS

In 24 of 28 bladder cancer patients (85.7%) LOH and MIN were found in urine sediment on at least one MS locus. Only in 3 of 28 patients(10.7%) was the urine cytology positive while MS and MIN were detected in these 3 patients. The conformance of MS alterations between cancer cells and urine sediment in the same patients was 94.1%. No MS alteration was found in 15 normal controls.

CONCLUSION

Application of microsatellite sequence of urine sediment can be considered as a new tool for screening and early diagnoses of bladder cancer.

[Melanoma antigen-3 expression in human hepatocellular carcinoma]

OBJECTIVE

To investigate the expression of melanoma antigen-3 (MAGE-3) mRNA in human hepatocellular carcinoma (HCC) and probe into the theoretical feasibility that MAGE-3 antigens can be developed as a new peptide vaccine for immunotherapy in HCC patients.

METHODS

The expression of MAGE-3 mRNA in HCC tissues and the adjacent non-HCC liver tissues was studied using RT-PCR in 45 HCC patients. The results were compared with those of 16 cirrhotic patients and 12 patients whose liver tissues were pathologically normal. MAGE-3 mRNA positive PCR products were DNA sequenced in 3 HCC patients. The sequenced fragments of MAGE-3 cDNA were used as template by which a [alpha(32)P] labeled probe was synthesized and employed for Southern blot analysis. HLA class I-A and -B typing of 43 HCC patients were assayed by ELISA.

RESULTS

Of the 45 HCC samples, 35 (78%) expressed MAGE-3 mRNA and six HCC adjacent tissues were also positive in MAGE-3 expression. Pathological examination showed cellular heteromorphism in these adjacent tissues. The non-HCC liver tissues from cirrhosis and normal liver samples were not MAGE-3 mRNA detectable. The DNA sequence confirmed that the target gene fragment in all of the 3 samples of PCR products was MAGE-3 cDNA. Southern blotting result confirmed that of RT-PCR assay. In HCC patients, the predominant types of HLA were A(2) (53.5%), A(11) (25.6%), A(24) (20.9%), A(33) (20.9%), B(13) (28.3%), and B(35) (23.2%). MAGE-3 mRNA expression in HCC showed no correlation with the level of serum AFP and the size of the tumor.

CONCLUSIONS

MAGE-3 mRNA is expressed at a high percentage of HCC samples. This tumor rejection antigen may be used as peptide vaccine for immunotherapy of HCC patients. The phenomena that some non-HCC adjacent tissues with heteromorphism can express MAGE-3 like their paired HCC tissues indicate that the expression of MAGE-3 may be an indicator in the early stage of carcinogenesis of liver tissues.

[The expression and clinical significance of keratin 19, 20 mRNA in different tumor cell lines and tumor tissues]

OBJECTIVE

To study the expression of keratin 19, 20 (K19, K20) in different tumor cell lines and tumor tissues and its clinical implication.

METHODS

Quantitative reverse transcription-polymerase chain reaction (RT-PCR) was employed to examine the specific expression of K19 and K20 mRNA in eleven tumor cell lines and 33 corresponding tumor tissue specimens.

RESULTS

The expression of K19 mRNA was detected in 4 kinds of tumor cell lines and all tumor tissues examined, but the magnitude of expression differed, with a difference ranging from 1.7 to 10 folds for the same type of cancer. In some patients, the level of expression was as low as 12% of the positive control. K20 mRNA expression was negative for lung and esophageal tumor cell lines and the corresponding carcinoma specimens. In one of 6 bladder cancer specimens and in 4 of 5 colorectal cancer tissues, K20 expression was positive, at a level of 41%-77% of the positive control. There was no expression of K20 in bladder tumor cell line EJ1 and colorectal tumor cell line SW480.

CONCLUSION

These results demonstrate that K19 and K20 may be used as a valuable marker for detecting circulating cancer cells, but the low level of expression in some cases of carcinoma would probably result in false negative results.

[Rapid construction of recombinant baculovirus carrying hepatitis B virus surface antigen gene by using a novel baculovirus shuttle vector(Bacmid)]

In order to express the HBV surface antigen (HBV) efficiently by using the Bac-to-Bac system and to produce HBsAg for diagnosis and vaccine development of HBV, a recombinant donor plasmid pFB-BS carrying HBsAg gene was constructed. The gene was inserted into shuttle plasmid (Bacmid) in E. coli DH10Bac with the help of Tn7 transposition system. The recombinant Bacmid was examined by PCR and transfected to Sf9 cells. HBsAg was expressed under the control of polyhedrin promoter of baculovirus in insect cells and was identified by ELISA. The quantity of the expression reached to 2 micrograms/10(6) cells and most production was within cells. Our data suggested that the Bac-to-Bac system can be used successfully and rapidly in the expression of viral gene.

[Expression of hepatitis C viral structure protein by recombinant vaccinia virus]

The hepatitis C viral (HCV) DNA fragment coding for the core and two glycoproteins E1 + E2/NS1 were inserted into vaccinia virus vector pJSA1175, under the control of the promoter 7.5K. 143TK- cells transfected with the HCV recombinant plasmid pJSA1175CE in the presence of infectious TK+ vaccinia virus (Tiantan stain) yielded recombinant vaccinia virus and expressed an approximately 90 kDa polyprotein. Southern blot hybridization showed that the inserted HCV cDNA was located at the vaccinia virus TK+ gene, J fragment. One polypeptide band between 106 and 80 kDa was revealed in SDS-PAGE which reacted with anti-core murine serum. The polypeptide could be secreted into the medium, the total amount was about the same as in the cells.