The association between interleukin-19 concentration and diabetic nephropathy.

BACKGROUND: Interleukin-19 (IL-19) is a newly discovered cytokine belonging to the Interleukin-10(IL-10) family. IL-19 have indispensable functions in many inflammatory processes and also can induce the angiogenic potential of endothelial cells. The purpose of present study was to investigate the relation of serum interleukin-19 (IL-19) levels with diabetic nephropathy (DN). METHODS: Two hundred study groups of patients with type 2 diabetes mellitus (T2DM) (109 males and 91 females) were recruited, included normoalbuminuria(n = 102), microalbuminuria(n = 72) and macroalbuminuria(n = 26) . The 50 healthy blood donors were enrolled for the control group. All subjects were assessed for: IL-19, High-sensitivity C-reactive protein (Hs-CRP), Cystatin C, urinary albumin excretion rate (UAE) and glycosylated hemoglobin A1c(HbA1c). RESULTS: The serum IL-19 levels in DN patients were found to be significantly higher compared to controls. IL-19 levels were significantly positively correlated with Hs-CRP, Cystatin C, UAE and HbA1c(r = 0.623, 0.611,0.591 and 0.526 respectively, P < 0.01). Multivariable logistic regression analysis showed IL-19 levels (P = 0.01) were found to be independently associated with patients with DN. CONCLUSIONS: IL-19 is significantly positive correlated with UAE and Cystatin C. IL-19 may play an important role that contributes to the progression of diabetic nephropathy.

[Overexpression of Toxoplasam gondii ROP18 by Tet-on Lentivirus Expression System].

OBJECTIVE: To construct a 293T mutant cell line over-expressing ROP18 of Toxoplasma gondii by Tet-on lentivirus expression system. METHODS: Rop18 gene of T. gondii was amplified by PCR, and inserted into a lentiviral vector pLVCT-tTR-KRAB. The recombinant plasmid pLVCT-tTR-KRAB-ROP18 (6 µg) and 293T human embryonic kidney cells were co-transfected with psPAX2 (4 µg) and pMD2.G (2 µg) for the packaging. The result of co-transfection was evaluated by fluorescence microscopy. At 48 h and 72 h after co-transfection, the supernatant of the packaging lentivirus was collected for the 293T cell infection. The doxycycline (DOX) was added into the medium to induce the ROP18 expression in 293T cells. The ROP18 fusion expression was observed under fluorescence microscope and detected by RT-PCR after induction. RESULTS: PCR product of the gene fragment encoding ROP18 was 960 bp. The recombinant plasmid pLVCT-tTR-KRAB-ROP18 was identified by PCR and restriction enzyme digestion. Green fluorescence was observed in 293T cells at 48 h post-transfection. Bright green fluorescence was observed in 293T cells at 24 h after DOX induction. RT-PCR results showed that a 960 bp specific band (ROP18 gene) was detectable in 293T cells. CONCLUSION: 293T cell line stably expressing ROP18 is established with Tet-on lentivirus expression system.

[Construction of beta-hydroxyacyl-acyl carrier protein dehydratase mutant of Toxoplasma gondii by tetracycline inducible expression system].

OBJECTIVE: To construct a beta-hydroxyacyl-acyl carrier protein dehydratase (FABZ) mutant of Toxoplasma gondii with tetracycline inducible expression system. METHODS: The fabz gene was amplified from T. gondii genomic DNA, and then used to construct the tetracycline inducible expression vector pTetO7-Sag1-FABZ-Ty-DHFR. The vector was transfected into TATi strain by electroporation. The FABZ defective mutant was selected by pyrimethamine and limitting dilution assay. The expression of Ty-tagged mutant was detected by Western blotting. 5 x 10(5) tachyzoites of FABZ defective mutant were cultured in HFF in the presence of anhydrotetracycline (ATc, 1 microg/ml) for 24 h and 48 h, respectively. The expression of Ty-tagged FABZ protein in the mutant was detected by Western blotting. RESULTS: The mutant could express the transit peptide (t-FABZ) and mature FABZ (m-FABZ) with the Ty-epitope tag. After ATc added in culture medium for 24 h and 48 h, the expression of t-FABZ in the mutant decreased significantly (P<0.05). CONCLUSION: The FABZ mutant is constructed with a tetracycline inducible expression system.

Separation and purification of Toxoplasma gondii tachyzoites from in vitro and in vivo culture systems.

In this study, we evaluated four methods to separate and purify Toxoplasma gondii tachyzoites from in vivo and in vitro culture systems, including trypsin digestion, purification with a 3-µm filter, CF-11 cellulose purification, and Percoll purification. Our results indicate that both purification with a 3-µm filter and CF11 cellulose purification methods remove leukocytes or HeLa cells, and can therefore be used as candidate methods for the purification of in vivo and in vitro culture products. Trypsin digestion had a high tachyzoite recovery rate, but 22.35% of leukocytes and 69.64% of HeLa cells remained in the purified products. Percoll solution [30% (v/v)] also had a high tachyzoite recovery rate, but 3.44% of leukocytes and 61.61% of HeLa cells remained in the purified products. The 40% Percoll solution was also a candidate method for purifying tachyzoites from in vivo culture products, with a 65.45% tachyzoite recovery rate and without leukocytes.

[Effects of oral type II collagen on serum antibody and the cytokine cxpression in Peyer's patches].

AIM: To explore the effects of oral type II collagen (CII) on the morphology, cytokine expressions of Peyer's patches(PP)and the levels of serum specific IgG, IgA, IgM. METHODS: CII was orally administrated to Kunming mice in continuous 10 days at different dosage. The CII or adjuvant immunization was given at 11 d and 21 d. The blood and Peyer's patches were collected at 11 d, 21 d and 31 d. The PP hyperplasy was observed by light microscope after HE staining. The fluorescent real time RT-PCR was used to detect the mRNA expressions of IL-17, TNF-α, IFN-γ and TGF-ß1 in PP lymph node. The serum specific IgG, IgA, IgM contents were detected by ELISA. RESULTS: After oral administration of CII for 10 d, the PP lymph node hyperplasia was active and the cap-shape structure could be seen clearly in high dose group, the serum IgA could be detected, the gene expressions of IL-17, TNF-α and IFN-γ were inhibited. After the CII initial immunity, the IgA, IgM, IL-17 levels were descended and TGF-ß1 level was increased in the experiment groups as compared with control group(P < 0.05 or P < 0.01). After the CII booster, IgA was notably increased in high dose group(P < 0.05), in experiment groups IgM was still suppressed (P < 0.05 or P < 0.01) and TGF-ß1 levels were higher than control group(P < 0.05). In adjuvant immunization groups the cytokine expressions were similar to CII immunization groups, the differences of serum specific IgG, IgA, IgM could not be observed as compared with control group. CONCLUSION: The oral administration of CII can increase the serum specific IgA and suppress the gene expressions of IL-17, TNF-α, IFN-γ in the Peyer's patches. It can still have inhibitory action on the serum specific IgA, IgM and IL-17 gene expressions after CII immunization. The results indicate that the changes of the serum specific antibodies and cytokine gene expressions play an important role on treating rheumatoid arthritis by oral CII to induce immune tolerance.

Efficacy of ginkgolic acids against Cryptosporidium andersoni in cell culture.

Cryptosporidium is a worldwide waterborne parasite and the treatment is a severe problem in immunocompromised patients. In this study, we used the in vitro culture system to evaluate the anti-Cryptosporidium activity of ginkgolic acids (GAs), nitazoxanide (NTZ), garlicin (GAR), and artemether (ART). The growth of Cryptosporidium andersoni in HCT-8 cells was determined by real-time PCR assay. When exposed to 5.00 µg/ml GAs or 10.00 µg/ml NTZ for 48 h, the number of C. andersoni in cultures was on a very low lever, but the number of parasites did not significantly decrease when exposed to GAR and ART. Our results indicate that GAs could be a potential drug for the treatment of cryptosporidiosis.

[Stable green fluorescent protein expression in Toxoplasma gondii mutant].

OBJECTIVE: To construct a Toxoplasma gondii mutant for stably expressing green fluorescent protein (GFP), and establish method to determine the rate of mutant-infected HeLa cells. METHODS: Freshly lysed-out tachyzoites of T. gondii RH strain were transfected with plasmid ptubP30-GFP/sag-CAT. Stable transformants were selected with chloramphenicol and limited dilution. The expression of GFP in mutant tachyzoite was determined by RT-PCR and fluorescence microscopy. When infected with 1 x 10(4)-1 x 10(7) mutant tachyzoites respectively for 24 h, the total number of HeLa cells with green fluorescence was determined by fluorescent microscope in 10 high-power fields, and the rate of HeLa cells with parasitophorous vacuole was determined by flow cytometry. RESULTS: Untransfected tachy-zoites were killed by chloramphenicol, while the stable transformants showed resistance to chloramphenicol. The expression of GFP gene was detected by RT-PCR. The P30-GFP transfectants displayed fluorescence outside the parasite. The rate of mutant-infected HeLa cells increased with the rise of the number of mutant for infection. When infected with 1 x 10(4)-1 x 10(7) tachyzoites, the numbers of HeLa cells with fluorescence were (14 +/- 6), (133 +/- 45), (332 +/- 93) and (443 +/- 90), and the rates of infected cells were (0.49 +/- 0.09)%, (8.76 +/- 0.50)%, (21.0 +/- 21.49)%, and (39.00 +/- 3.47)% by flow cytometry, respectively. CONCLUSION: T. gondii mutant with GFP tag is constructed, which provides a new method to determine the proliferation when cultured in host cells.

[Real-time PCR in analyzing DNA extraction from Cryptosporidium oocysts].

OBJECTIVE: To compare the quality and quantity of DNA extracted from Cryptosporidium oocysts by different methods. METHODS: Cryptosporidium oocysts were treated with different kinds of lysis buffers from USA Promega (Promega) and Shanghai Generay (Generay) commercial DNA extraction kits, 2% Triton X-100 and 5% guanidine thiocyanate. The oocysts were then broken down by freeze-thawing, proteinase K and sonication. Genomic DNA was purified using the commercial kits or Chelex-100. Real-time PCR technique was used to determine the copies of Cryptosporidium oocyst wall protein (COWP) gene. The Promega commercial DNA extraction kit was used as control. RESULTS: The Promega kit resulted in a higher copy number of COWP gene [(6.45-9.86) x 10(6)] than that of Generay commercial DNA kit [(2.38-3.69) x 10(6)], 5% guanidine thiocyanate [(1.27-21.29) x 10(5)] or 2% Triton X-100 [(2.06-866.70) x 10(3)] , respectively. The method of freeze-thawing plus proteinase K plus sonication provided the highest copy number of COWP gene. CONCLUSION: The method of freeze-thawing + proteinase K + sonication is most effective. The effect of DNA extraction by Generay kit and 5% guanidine thiocyanate is similar to that of Promega kit.

Toxoplasma gondii: a simple Real-time PCR assay to quantify the proliferation of the apicoplast.

A Real-time quantitative PCR assay to quantify the Toxoplasma gondii apicoplast was studied. Primers were designed to amplify a 305bp product specific to T. gondii apicoplast. Standard curves were generated for both T. gondii apicoplast DNA and genomic DNA, and were used to compute the relative concentration of apicoplast DNA copies in the test samples. The results indicated that the copies of T. gondii apicoplast DNA was significantly low when exposed to ciprofloxacin, clindamycin and azithromycin for 48h in the second infectious cycle. Our study shows that the Real-time PCR technique is a simple and quick technique for screening the anti-apicoplast drugs.

Effect of select medium supplements on in vitro development of Cryptosporidium andersoni in HCT-8 cells.

We evaluated the effect of fetal calf serum (FCS), glucose, ascorbic acid, calcium pantothenate, folic acid, and insulin on the growth of Cryptosporidium andersoni in human colon tumor (HCT-8) cells. After being incubated for 48 h, the proliferation of parasites was determined by real-time polymerase chain reaction (PCR) assay, and the development of C. andersoni was observed by transmission electron microscopy (TEM). Ten percent FCS was the best concentration for C. andersoni culture. Glucose, ascorbic acid, and insulin had a significant effect on the growth of C. andersoni when added into 10% FCS RPMI 1640. Calcium pantothenate had no significant effect and folic acid had the inhibited effect. We also observed the stages of trophozoite, macrogamont, microgamont, type I meront, type II meront, and sporozoite of C. andersoni in HCT-8 cells by TEM. Our results indicated that the best medium for C. andersoni was 10% FCS RPMI 1640 medium containing 50 mM glucose, 50 microg/ml ascorbic acid, and 0.3 U/ml insulin. Real-time PCR could provide a quick and precise technique to determine the proliferation of parasites. Cultivation of C. andersoni in HCT-8 cells will facilitate the study of interactions between parasites and host cells as well as provide a reliable system for evaluating anticryptosporidial compound efficacy.

Anti-Toxoplasma gondii activity of GAS in vitro.

ETHNOPHARMACOLOGICAL RELEVANCE: The sarcotesta of Ginkgo biloba is a Chinese herbal medicine used for treating toxoplasmosis, a serious disease requiring treatment with antibiotics that can have serious side effects. AIM OF THE STUDY: To investigate the anti-Toxoplasmagondii activity of ginkgolic acids (GAs) isolated from the Ginkgo biloba sarcotesta in Toxoplasmagondii-infected human foreskin fibroblast (HFF) cells in vitro. MATERIALS AND METHODS: The safe concentration of GAs for HFF cells was determined by methyl thiazolyl tetrazolium (MTT) cell proliferation assay. The presence of Toxoplasmagondii was measured by [3H]-thymine deoxyriboside ([3H]-TdR) and [3H]-leucine ([3H]-Leu) incorporation, as well as Giemsa staining. The positive control was the commonly used and highly effective antibiotic azithromycin. RESULTS: Light microscopy revealed that most HFF cells were infected after 4h of exposure to Toxoplasmagondii. After 48 h of exposure to either GAs or azithromycin, Toxoplasmagondii DNA and protein synthesis were minimal, there were no visible parasites in HFF cells, and the HFF cells had no significant morphological changes. CONCLUSIONS: These results demonstrate that GAs have significant anti-Toxoplasma activity with low toxicity to HFF cells, suggesting that GAs could be an alternative treatment for toxoplasmosis.

[In vitro culture of tachyzoites of Toxoplasma gondii RH strain in HeLa cells].

OBJECTIVE: To establish a stable and efficient in vitro culture model for tachyzoites of Toxoplasma gondii RH strain. METHODS: Tachyzoites were inoculated into HeLa cells to establish an in vitro culture system. The proliferation of tachyzoites was observed under microscope by the method of Giemsa stain. At the same time, the longterm tachyzoites maintenance in HeLa cells was established, and the effect of different temperature and time on the yield and motility of tachyzoites were observed. RESULTS: The RH strain tachyzoites were cultured and maintained in HeLa cells. Most HeLa cells were destroyed 96 h after inoculation. In the long-term culture system, the proliferation of tachyzoites was stable and its virulence to mouse showed no decrease. Furthermore, tachyzoites in this system proliferated by 5-20 times and (1-5) x 10(7) tachyzoites were harvested. When cultured in HeLa cells at 37 degrees C for 72h then at 25 degrees C for another 120 h, the tachyzoites proliferated by more than 40 times with a motility rate of over 90%. However, rare HeLa cells left in the medium were found. CONCLUSION: Tachyzoites of T. gondii RH strain can be subcultured in HeLa cells for a long time, and high proliferation rate of tachyzoites can be obtained from this in vitro culture system.

[Detection of Pneumocystis carinii DNA in rats by PCR-ELISA].

OBJECTIVE: To establish a PCR-ELISA and evaluate its use in detecting DNA of Pneumocystis carinii (P. c) in rat model. METHODS: SD rats and Wistar rats were used in the experiment. P. c DNA from rat lung tissue and BALF was amplified by PCR. The amplified products were visualized by ethidium bromide (EB) staining after agarose gel electrophoresis or detected by ELISA. The results were compared with that by Giemsa stain. RESULTS: The positive rate in the two species of rats by the two methods was 96.4% and 100% in lung tissue, 96.4% and 100% in BALF, respectively, with no significant difference (P>0.05). Giemsa positive samples were all positive by PCR-ELISA. The negative control group had one positive by ELISA in lung tissue and BALF respectively. CONCLUSION: PCR-ELISA shows a high sensitivity and specificity in detecting the DNA of Pneumocystis carinii, which is a secure and easy use method.