[Mechanism of n-butanol alcohol extract of Baitouweng Decoction in treatment of vulvovaginal candidiasis based on negative regulation of NLRP3 inflammasome via PKCδ/NLRC4/IL-1Ra axis]

This study aimed to explore the mechanism of n-butanol alcohol extract of Baitouweng Decoction(BAEB) in the treatment of vulvovaginal candidiasis(VVC) in mice based on the negative regulation of NLRP3 inflammasome via PKCδ/NLRC4/IL-1Ra axis. In the experiment, female C57BL/6 mice were divided randomly into the following six groups: a blank control group, a VVC model group, high-, medium-, and low-dose BAEB groups(80, 40, and 20 mg·kg~(-1)), and a fluconazole group(20 mg·kg~(-1)). The VVC model was induced in mice except for those in the blank control group by the estrogen dependence method. After modeling, no treatment was carried out in the blank control group. The mice in the high-, medium-, and low-dose BAEB groups were treated with BAEB at 80, 40, and 20 mg·kg~(-1), respectively, and those in the fluconazole group were treated with fluconazole at 20 mg·kg~(-1). The mice in the VVC model group received the same volume of normal saline. The general state and body weight of mice in each group were observed every day, and the morphological changes of Candida albicans in the vaginal lavage of mice were examined by Gram staining. The fungal load in the vaginal lavage of mice was detected by microdilution assay. After the mice were killed, the degree of neutrophil infiltration in the vaginal lavage was detected by Papanicolaou staining. The content of inflammatory cytokines interleukin(IL)-1β, IL-18, and lactate dehydrogenase(LDH) in the vaginal lavage was tested by enzyme-linked immunosorbent assay(ELISA), and vaginal histopathology was analyzed by hematoxylin-eosin(HE) staining. The expression and distribution of NLRP3, PKCδ, pNLRC4, and IL-1Ra in vaginal tissues were measured by immunohistochemistry(IHC), and the expression and distribution of pNLRC4 and IL-1Ra in vaginal tissues were detected by immunofluorescence(IF). The protein expression of NLRP3, PKCδ, pNLRC4, and IL-1Ra was detected by Western blot(WB), and the mRNA expression of NLRP3, PKCδ, pNLRC4, and IL-1Ra was detected by qRT-PCR. The results showed that compared with the blank control group, the VVC model group showed redness, edema, and white secretions in the vagina. Compared with the VVC model group, the BAEB groups showed improved general state of VVC mice. As revealed by Gram staining, Papanicolaou staining, microdilution assay, and HE staining, compared with the blank control group, the VVC model group showed a large number of hyphae, neutrophils infiltration, and increased fungal load in the vaginal lavage, destroyed vaginal mucosa, and infiltration of a large number of inflammatory cells. BAEB could reduce the transformation of C. albicans from yeast to hyphae. High-dose BAEB could significantly reduce neutrophil infiltration and fungal load. Low-and medium-dose BAEB could reduce the da-mage to the vaginal tissue, while high-dose BAEB could restore the damaged vaginal tissues to normal levels. ELISA results showed that the content of inflammatory cytokines IL-1β, IL-18, and LDH in the VVC model group significantly increased compared with that in the blank control group, and the content of IL-1β, IL-18 and LDH in the medium-and high-dose BAEB groups was significantly reduced compared with that in the VVC model group. WB and qRT-PCR results showed that compared with the blank control group, the VVC model group showed reduced protein and mRNA expression of PKCδ, pNLRC4, and IL-1Ra in vaginal tissues of mice and increased protein and mRNA expression of NLRP3. Compared with the VVC model group, the medium-and high-dose BAEB groups showed up-regulated protein and mRNA expression of PKCδ, pNLRC4, and IL-1Ra in vaginal tissues and inhibited protein and mRNA expression of NLRP3 in vaginal tissues. This study indicated that the therapeutic effect of BAEB on VVC mice was presumably related to the negative regulation of NLRP3 inflammasome by promoting PKCδ/NLRC4/IL-1Ra axis.

[Recommendations of diagnosis and treatment of relapsing polychondritis in China]

Relapsing polychondritis is an immune mediated systemic inflammatory disease, involving the cartilaginous and proteoglycan rich structures. The characteristic manifestations were inflammation and deformity of ear and nasal cartilage. Here, Chinese Rheumatology Association summarized manifestations, diagnosis and disease activity index evaluation of relapsing polychondritis, standardized treatment regimens, to improve disease prognosis.

[Activity of essential oil extracted from Artemisia argyi in inducing apoptosis of Candida albicans]

To explore the activity of essential oil extracted from Artemisia argyi (AAEO) in inducing the apoptosis of Candida albicans SC5314. The effect of AAEO on reactive oxygen species(ROS) and mitochondria membrane potential(MMP) of C. albicans SC5314 was detected by flow cytometry. Phosphatidylserine externalization was observed under fluorescence microscopic with Annexin-V/PI staining at the early stage of apoptosis in C. albicans. Metacaspase activity was observed under fluorescence microscopic with FITC-VAD-FMK staining at the early stage of apoptosis in C. albicans. C. albicans morphology was observed by DAPI nuclear staining and fluorescence microscopy. After intervention with 0.5 mL•L⁻¹ AAEO, apoptosis of C. albicans significantly increased, metacaspase activity increased, nuclear pyknosis and fragmentation, and intracellular ROS were significantly increased, and mitochondrial membrane potential decreased significantly. The certain concentrations of AAEO could induce the apoptosis of C. albicans.

[Role of circulating T follicular helper subsets and T follicular helper effector memory cells in systemic lupus erythematosus]

Objective: To investigate the role of T follicular helper (Tfh) subsets and T follicular helper effector memory (Tfhem) cells in circulation of patients with systemic lupus erythematosus (SLE), and explore their roles in SLE disease activity index as biomarkers. Methods: This study enrolled 64 patients with SLE and 15 healthy controls. In peripheral blood from patients with SLE and health controls, the percentage of Tfhem (CD3(+)CD4(+)CD45RA(-)CXCR5(+)CCR7(low)PD-1(high)) cells, Tfh (CD3(+)CD4(+)CD127(high)CD25(l)ow CD45RA(-)CXCR5(+)) subset: Tfh1 (CXCR3(+)CCR6(-)Tfh), Tfh2 (CXCR3(-)CCR6(+) Tfh), Tfh17 (CXCR3(-)CCR6(+) Tfh), were detected by flow cytometry. The correlations of Tfhem/Tfh subsets with clinical indicators which we collected were analyzed. Results: The percentage of Tfhem was significantly increased in SLE patients compare to health controls (1.40±1.12 vs 0.51±0.24, P<0.000 1), and it was also correlated with systemic lupus erythematosus disease activity index (SLEDAI) (P=0.015 3) and anti-dsDNA antibody (P=0.003 1), but not with complement C3 (C3), complement C4 (C4), erythrocyte sedimentation rate (ESR), and C reaction protein (CRP). In addition, the percentage of Tfh2, but not Tfh1 or Tfh17, was significantly increased in SLE patients compare to health controls (3.83±2.74 vs 2.18±1.07, P=0.000 4). As compared to anti-dsDNA antibody<25 group, the percentage of Tfh2 in anti-dsDNA antibody>25 group was increased with no significant statistical difference (4.33±3.20 vs 3.70±1.070, P=0.069 6). Conclusion: Our investigation show that Tfhem is associated with SLEDAI and it is a valuable evaluation biomarker for disease process and treatment. Meanwhile Tfhem is also associated with anti-dsDNA antibody, and it plays an important role in autoantibody production in SLE pathogenesis. Tfhem may be a good therapeutic target in SLE. For the meantime, the percentage of Tfh2 is significantly increased in SLE patients, and it had certain correlation with anti-dsDNA antibody, it might be involved in the development of SLE.

[Inhibitory effect of extract of Coptidis Rhizoma on invasion of Candida albicans hyphae in vitro]

The aim of this paper was to investigate the inhibitory effect of extract of Coptidis Rhizoma(ECR) on invasion of Candida albicans hyphae in vitro.XTT reduction method was used to evaluate the metabolic activity of C.albicans.The colony edge growth of C.albicans was observed by solid medium.The growth of C.albicans hyphae was determined on semi-solid medium.The morphology and viability changes of C.albicans hyphae were assessed by scanning electron microscope and fluorescence microscope.qRT-PCR method was used to detect the ALS3 and SSA1 expression of C.albicans invasin genes.The results showed that the metabolic viability by XTT method detected that the activity of C.albicans was gradually decreased under the intervention of 64,128 and 256 mg·L-1 of ECR respectively.128,256 mg·L-1 of ECR significantly inhibited colony folds and wrinkles on solid medium and the hyphal invasion in semi-solid medium.Scanning electron microscopy and fluorescence microscopy showed that 128,256 mg·L-1 of ECR could inhibit the formation of C.albicans hyphae.qRT-PCR results showed that the expression of invasin gene ALS3 and SSA1 was down-regulated,and especially 256 mg·L-1 of ECR could down-regulate the two genes expression by 4.8,1.68 times respectively.This study showed that ECR can affect the invasiveness of C.albicans by inhibiting the growth of hyphae and the expression of invasin.

Mechanism of berberine-mediated fluconazole-susceptibility enhancement in clinical fluconazole-resistant Candida tropicalis isolates

BACKGROUND

Candida tropicalis was one of the most common non-albicans Candida (NACA) species creating relatively high morbidity and mortality. We previously demonstrated that the antifungal effect of BBR in combination with FLC might be attributed to reactive oxygen species production, ergosterol content and efflux pump levels in a clinical C. tropicalis isolate.

METHODS

we employed thirteen clinical C. tropicalis isolates as well as four standard reference strains to evaluate the antifungal activity of BBR in combination with FLC under planktonic and biofilm states by analyzing the mRNA expressions of ERG11, CDR1 and MDR1 by qRT-PCR.

RESULTS

The susceptibility tests showed that BBR in combination with FLC produced a FICI range of 0.13-1 under planktonic state and 0.25-1 under biofilm state in the seventeen strains. The mRNA expressions of ERG11, CDR1 and MDR1 were upregulated 1.43-2.10 and 1.47-4.42 fold in the case of BBR/FLC used alone compared with the control. The combined usage of BBR plus FLC resulted in a decrease of 2.84- (p<0.01) and 2.39-fold (p<0.05) in the expression of ERG11 mRNA, 2.98- (p<0.05) and 3.06-fold (p<0.05) in the expression of CDR1 mRNA, 1.41- and 4.33-fold in the expression of MDR1 mRNA compared with the BBR/FLC used alone.

CONCLUSION

The synergism of BBR with FLC might be relevant with the inhibitions on the mRNA expressions of ERG11 and efflux pumps.

Antiproliferation of Berberine in Combination with Fluconazole from the Perspectives of Reactive Oxygen Species, Ergosterol and Drug Efflux in a Fluconazole-Resistant Candida tropicalis Isolate

Candida tropicalis has emerged as an important pathogenic fungus in nosocomial infections due to its recalcitrant resistance to conventional antifungal agents, especially to fluconazole (FLC). Berberine (BBR) is a bioactive herbal-originated alkaloids and has been reported to possess antifungal functions against C. albicans. In this paper, we tried to figure out the antifungal mechanisms of BBR and/or FLC in a clinical C. tropicalis isolate 2006. In the microdilution test, the minimum inhibitory concentration (MIC) of BBR was found 16 μg/mL with fractional inhibitory concentration index (FICI) 0.13 in C. tropicalis 2006. The synergism of BBR and FLC was also confirmed microscopically. After the treatments of BBR and/or FLC, the studies revealed that (i) FLC facilitated BBR to increase reactive oxygen species (ROS), (ii) FLC enhanced the intranuclear accumulation of BBR, (iii) BBR decreased the extracellular rhodamine 123 (Rh123) via inhibiting efflux transporters, (iv) FLC assisted BBR to reduce ergosterol content, and (v) BBR in combined with FLC largely downregulated the expressions of Candida drug resistance 1 (CDR1) and CDR2 but impact slightly multidrug resistance 1 (MDR1), and upregulate the expression of ergosterol 11 (ERG11). These results suggested that BBR could become a potent antifungal drug to strengthen FLC efficacy in FLC-resistant C. tropicalis via ROS increase, intracellular BBR accumulation, ergosterol decrease and efflux inhibition.

[Intervention of systolic pressure and left ventricular hypertrophy in rats under cold stress]

OBJECTIVE

To investigate the effects of different drugs on systolic blood pressure (SBP) and left ventricular hypertrophy (LVH) in spontaneously hypertensive rats under cold stress.

METHODS

A total of 40 male spontaneously hypertensive rats aged 10 weeks (160~200 g) were given adaptive feeding for 7 days at a temperature of 20±1°C and then randomly divided into control group, cold stress group, metoprolol group, amlodipine group, and benazepril group, with 8 rats in each group. SBP, body weight, and heart rate were measured once a week. After the rats were sacrificed by exsanguination, left ventricular weight (LVW) was measured, and left ventricular weight index (LVWI; mg/g) was calculated. Radioimmunoassay was used to measure the concentrations of endothelin-1 (ET-1) and angiotensin-II (Ang-II) in plasma and myocardium, and the chemical method was used to measure the concentrations of nitric oxide (NO) in plasma and myocardium. RT-PCR was used to measure the mRNA expression of endothelin-A receptor.

RESULTS

Compared with the cold stress group, all medication groups showed significant reductions in SBP since week 5 (P<0.05). The cold stress group showed a significant increase in LVWI compared with the control group (3.38±0.27 mg/g vs 2.89±0.19 mg/g, P<0.05). The amlodipine group showed a significant reduction in LVWI compared with the cold stress group (2.98±0.28 mg/g vs 3.38±0.27 mg/g, P<0.05). The cold stress group showed a significant reduction in plasma NO concentration compared with the control group (104.9±19.5 μmol/L vs 129.3±17.8 μmol/L, P<0.05) ; compared with the cold stress group, all the medication groups showed significant increases in blood NO concentration (P<0.05). The cold stress group showed a significant increase in myocardial ET-1 concentration compared with the control group (6.3±1.5 pg/100 mg vs 4.5±1.9 pg/100 mg, P<0.05) ; compared with the cold stress group, the amlodipine group showed a significant reduction in myocardial ET-1 concentration (4.4±1.0 pg/100 mg vs 6.3±1.5 pg/100 mg, P<0.05). The cold stress group had significantly higher mRNA expression of endothelin-A receptor than the control group (0.86±0.23 vs 0.45±0.16, P<0.01) ; compared with the cold stress group, the amlodipine group showed a significant reduction in the mRNA expression of endothelin-A receptor (0.41±0.14 vs 0.86±0.23, P<0.01).

CONCLUSION

Amlodipine can reduce the increase in SBP and inhibit LVH in spontaneously hypertensive rats under cold stress.

[New advance in studies on antimicrobal activity of Scutellaria baicalensis and its effective ingredients]

In recent years, with the constant increase in the population with hypoimmunity, bacterial and fungal infections have been increasing. Due to the drug resistance, clinically optional anti-bacterial and antifungal medicines become increasingly limited. Scutellaria baicalensis, a species of perennial herbaceous plant of scutellaria genus of lamiaceae family, and its effective components have multiple pharmacological effects such as anti-inflammation, anti-oxidation, anti-tumor, anti-microbial. Especially, its remarkable antibacterial and antifungal activities are of great significance to treat the increasing number of cases with drug-fast bacterial and antifungal infections. In this paper, the authors summarized the advance in studies on antibacterial and antifungal effects and mechanisms in recent years on the basis of the domestic and foreign studies on S. baicalensis and its effective ingredients.

[Effect of andrographolide on Candida albicans biofilm dispersion]

Along with the increase in fungal infections, Candida albicans prevention and control become the focus of anti-fungal infection at present. This study aims to discuss the effect monomer andrographolide (AG) on C. albicans biofilm dispersion. In the experiment, micro-well plates and medical catheter pieces were used to establish the C. albicans biofilm model. It was discovered by XTT assay and flat band method that 1 000, 500, 250 mg x L(-1) AG could impact the activity of C. albicans biofilm dispersion cells. The morphological structures of residual biofilms on catheter pieces were observed with scanning electron microscopy, which showed that 1 000, 500, 250 mg x L(-1) AG could induce C. albicans biofilm dispersion in a dose-dependent manner, and the dispersed cells were dominated by the yeast phase. According to the real-time fluorescence quantification PCR (qRT-PCR) test, AG could up-regulate HSP90 expression and down-regulate UME6 and PES1 expressions. This study demonstrates that AG could induce C. albicans biofilm dispersion to some extent.

[Effect of andrographolide derivative Yanhuning on in vivo Candida albicans biofilms in rats]

OBJECTIVE

To investigate the effect of andrographolide derivative Yanhuning (YHN) on Candida albicans biofilms in rats.

METHOD

The rat C. albicans biofilms subcutaneous catheter model was established by intraperitoneally injecting YHN (40, 20, 10, 5, 2.5 mg x kg (-1)), with the FLC (80 mg x kg(-1)) positive group as the control group. After 7 d, CFU counting and XTT assay were used to evaluate the effect of YHN on C. albicans biofllms in vivo. Scanning electron microscopy (SEM) was applied to observe the morphological changes in rat biofilms intervened by YHN. The real-time fluorescence quantification PCR was adopted to detect expressions of C. albicans adhesion-related genes, such as ALS1, ALS3, HWP1, EAP1 and MP65.

RESULT

The YHN group showed much less CFUs on catheter pieces and lower XTT metabolic activity than the blank group, with dosage dependence. SEM also showed that YHN could obviously decrease C. albicans adhesion on subcutaneous catheters in rats. According to qRT-PCR's results, YHN can down-regulate expressions of ALS1, ALS3, HWP1, EAP1 and MP65.

CONCLUSION

YHN could inhibit C. albicans biofilms in rats.

[Study on inhibitory effect of different extract fractions from longdan xiegan decoction on biofilms of Candida albicans]

OBJECTIVE

To observe the inhibitory effect of different extract fractions from Longdan Xiegan decoction on biofilms of Candida albicans, and discuss its possible mechanism.

METHOD

The micro-dilution method and the XTT reduction assay were adopted to explore the antifungal activity of different extract fractions from Longdan Xiegan decoction and detect the inhibitory effect of different extracts on biofilms of C. albicans. The expression quantity of the adhesion related gene ALS1 and hypha formation SUN41 were detected by qRT-PCR.

RESULT

The MICs of extracts from Longdan Xiegan decoction, including petroleum ether, water, butanol, methanol and ethyl acetate, against C. albicans were > 1 000, > 1 000, > 1 000, 125, 125 mg x L(-1). The SMIC50 against biofilms of C. albicanswere > 1 000, > 1000, > 1 000, 500, 500 mg x L(-1). The SMIC50 were > 1 000, > 1 000, > 1 000, > 1 000 and 1 000 mg x L(-1). 1 000 mg x L(-1) ethyl acetate extracts could considerably inhibit the expression of the adhesion related gene ALS1 and hypha formation SUN41.

CONCLUSION

The ethyl acetate extract showed the greatest activity against Candida albicans biofilms.

[Advance in studies on anti-infection of andrographolide and its derivatives in past 10 years]

Andrographolide (AG) is a main effective ingredient in leaves of Andrographis paniculata. AG and its derivatives have such effects in anti-infection, anti-tumor and immuno-regulation. Particularly, its antibacterial, antiviral and anti-protozoal activities play an increasingly important role in resisting opportunistic infections. On the basis of our studies on AG over the years, we made a summary for the basis and clinical studies on AG and its derivatives over the past 10 years.

Modification of glycosylation reduces microvilli on rat liver epithelial cells

Effect of glycosylation modification on the shape of microvillus was investigated on rat liver epithelial cell line WB-F344. Since rat ER alpha-mannosidase has 89% identity to human 6A8 alpha-mannosidase, we used an antisense 6A8 cDNA fragment to inhibit expression in WB-F344 cells. Cells were transfected with antisense 6A8, the relevant sense fragment or the mock plasmid. Genomic PCR for neo(R) demonstrated integration of the transfected gene into host DNA. Enzymatic activity assay on p -nitro-phenyl-alpha-D-mannopyranoside showed suppression of ER alpha-mannosidase expression in the cells transfected with antisense 6A8. Concanavalin A binding to these cells was enhanced, indicating a modification in glycosylation. Number reduction and blunting of microvillus on these cells was observed. Transduction with the sense fragment or the mock had no effect. Cells with suppressed ER alpha-mannosidase expression grew slower in culture. Our results indicate an obvious effect of glycosylation modification on microvilli, which might be related with malfunctioning of cells.

Accumulation and acute toxicity of silver in Potamogeton crispus L

In the present study, Potamogeton crispus L. plants exposed to various concentrations of silver (Ag) (5, 10, 15, and 20 microM) for 5d were investigated to determine the accumulating potential of Ag and its influence on nutrient elements, chlorophyll pigments and fluorescence, various antioxidant enzymes and compounds, adenosine triphosphate (ATP), protein content and ultrastructure. The accumulation of Ag was found to increase in a concentration dependent manner with a maximum of 29.3 microg g(-1) at 20 microM. The nutrient elements (except Ca), photosynthetic pigments, chlorophyll a fluorescence parameters (Fo, Fv, Fv/Fm, Fv/Fo), malondialdehyde (MDA), ATP, peroxidase (POD) activity, ascorbate (AsA), reduced glutathione (GSH) and protein contents decreased significantly as concentration of Ag augmented. In contrast, an induction in SOD activity was recorded, while an initial rise in Ca content and CAT activity was followed by subsequent decline. Morphological symptoms of senescence phenomena such as chlorosis and damage of chloroplasts and mitochondria were observed even at the lowest concentration of Ag, which suggested that Ag hastened the senescence of the tested plants. The loss of nutrients and chlorophyll content and damage of chloroplasts were associated with disturbances in photosynthetic capacity as indicated by the quenching of chlorophyll a fluorescence. Decreased chlorophyll and protein contents suggest oxidative stress induced by Ag. In addition, both the reduction of ATP and the damage to the ultrastructure of organelles were indicative of general disarray in the cellular functions exerted by Ag.

Inhibition of 6A8 alpha-mannosidase gene expression resulted in telomere length shortening in nasopharyngeal carcinoma cell CNE-2L2

Telomere length shortening was observed in the nasopharyngeal carcinoma cell CNE-2L2 when 6A8 alpha-mannosidase expression was inhibited by antisense 6A8 DNA. Transduction with mock or an irrelevant DNA did not affect the telomere length in the carcinoma cells. Telomerase activity and mRNA transcription of TRF 1 and 2 were not changed in the cells treated with antisense 6A8. The Con A binding test showed an enhancement on the proteins isolated from the cells treated with antisense 6A8, but not on those from mock- or irrelevant DNA-treated cells. The data imply an association between glycosylation modification with telomere shortening in antisense 6A8-treated cells.

[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.

Long-term expression of a transferred gene in Epstein-Barr virus transformed human B cells

Delivering a gene into the Epstein-Barr virus (EBV)-transformed B cells is useful in studying effects of the gene on B-cell functions. However, although people have been able to efficiently transfer genes into and get them expressed in B-lympho blastoid cells for a time probably long enough to kill the cells using vectors harbouring oriP, the expression time of the delivered gene is not long enough in order to study the gene function in B cells. To solve this problem, we constructed an adeno-associated virus (AAV) plasmid pAGX(+) based on plasmids pSub201 and pRc/CMV. We developed and packaged recombinant AAV (rAAV) expression vectors containing an antisense or a sense DNA fragment of 6A8 cDNA encoding a human alpha-mannosidase, or an antisense fragment of 5D4 cDNA encoding a human cell membrane protein, or EYFP DNA. EBV-transformed B cell SKW6 and 3D5 were transduced with those rAAV or the mock. Transduction with the rAAV-EYFP showed an infection frequency of 64 +/- 3.5% and 58 +/- 6.2% for SKW6 and 3D5 cell, respectively. Genomic polymerase chain reaction (PCR) for neoR gene indicated an integration of the transferred gene into the host DNA. After being cultured and propagated for over 12 months, the cells were detected for the expression of the transferred gene. The RT-PCR, enzymatic assay and Con A binding test demonstrated an inhibition of 6A8 alpha-mannosidase in both SKW6 and 3D5 cells transduced with the antisense 6A8 DNA. Immunofluorescence staining with monoclonal antibodies (MoAb) 5D4 showed a reduction of the 5D4 protein expression on both the cells transduced with the antisense 5D4 DNA. The DNA fragmentation assay showed a resistance of the cells with 6A8 alpha-mannosidase inhibition to apoptosis induction by anti-Fas antibody. The data indicate that the AAV vector pAGX(+) can efficiently introduce genes into EBV-transformed B cells and the delivered gene can be expressed in the cells for more than 12 months which may be long enough for the study of gene functions in B cells.

Cloning, expression and characterization of a cDNA (6A8) encoding a novel human alpha-mannosidase

A 3300-bp cDNA (6A8) has been isolated from a human tonsil cell lambdagt11 cDNA library (GenBank accession number: AF044414). The 6A8 gene is localized on human chromosome 13q31-32. Its cDNA has an open reading frame from position 57 bp to 3243 bp, encoding a 1062 amino-acid polypeptide. The sequence of the polypeptide has 89% identity to rat liver ER alpha-mannosidase. Homogenates of COS-7 cells transfected with 6A8 cDNA showed an enhanced enzymatic activity with p-nitro-phenyl-alpha-D-mannopyranoside, which was not inhibited by swainsonine. These data suggest that 6A8 alpha-mannosidase belongs to the class II alpha-mannosidase. Western blot analysis showed a band for 6A8 cDNA encoded protein of approximately 120 kDa. Northern blot analysis revealed two 6A8 mRNA transcripts with different tissue distribution. Enhanced concanavalin A (ConA) binding to CNE-2L2 cells transfected with a reverse 6A8 DNA was observed, indicating that the 6A8 protein is an important cellular alpha-mannosidase.

Metabolites of Colletotrichum gloeosporioides, an endophytic fungus in Artemisia mongolica

A new antimicrobial metabolite, named colletotric acid (1), was isolated from a liquid culture of Colletotrichum gloeosporioides, an endophytic fungus colonized inside the stem of Artemisia mongolica. The structure was determined using spectroscopic methods (EIMS and FABMS,(1)H and (13)C NMR, (1)H-(1)H COSY, HMBC, and HMQC). Compound 1 inhibited the growth of Bacillus subtilis, Staphylococcusaureus, and Sarcina lutea with minimal inhibitory concentrations (MICs) of 25, 50, and 50 microg/mL, respectively, and the crop pathogenic fungus Helminthosporium sativum (MIC: 50 microg/mL).