Transcriptome analysis of developing zebrafish (Danio rerio) embryo following exposure to Gaudichaudione H reveals teratogenicity and cardiovascular defects caused by abnormal iron metabolism.

Gaudichaudione H (GH), a caged polyprenylated xanthone from Garcinia plants, showed anti-cancer and anti-inflammatory effects in vitro. However, the in vivo toxicity of this compound has never been reported. The present study was aimed to address the toxic effects of Gaudichaudione H using zebrafish embryos and larvae as an in vivo test model. The zebrafish embryos were treated with GH having different concentrations (0, 0.28, 0.38 and 0.57 µg/mL). The results revealed that GH induces significant embryonic mortality, decreased heartbeat, cardiotoxicity, cardiovascular defects, increased apoptosis and decreased hemoglobinization in zebrafish embryos and larvae. According to transcriptome analysis, 1841 genes were significantly differentially expressed (1185 down-regulated and 656 up-regulated) after GH treatment. The main functions of these genes were related to iron metabolism pathways. The toxicity of GH on zebrafish embryonic development and cardiovascular may due to large amounts of downregulated genes involved in metabolic pathways and DEGs related to 'Iron ion binding' and 'Heme binding' functions.

Physalin B reduces Aß secretion through down-regulation of BACE1 expression by activating FoxO1 and inhibiting STAT3 phosphorylation.

Physalin B (PB), one of the major active steroidal constituents of Solanaceae Physalis plants, has a wide variety of biological activities. We found that PB significantly down-regulated ß-amyloid (Aß) secretion in N2a/APPsw cells. However, the underlying mechanisms are not well understood. In the current study, we investigated the changes in key enzymes involved in ß-amyloid precursor protein (APP) metabolism and other APP metabolites by treating N2a/APPsw cells with PB at different concentrations. The results indicated that PB reduced Aß secretion, which was caused by down-regulation of ß-secretase (BACE1) expression, as indicated at both the protein and mRNA levels. Further research revealed that PB regulated BACE1 expression by inducing the activation of forkhead box O1 (FoxO1) and inhibiting the phosphorylation of signal transducer and activator of transcription 3 (STAT3). In addition, the effect of PB on BACE1 expression and Aß secretion was reversed by treatment with FoxO1 siRNA and STAT3 antagonist S3I-201. In conclusion, these data demonstrated that PB can effectively down-regulate the expression of BACE1 to reduce Aßsecretion by activating the expression of FoxO1 and inhibiting the phosphorylation of STAT3.

[Effect and Mechanism of Sulforaphane on G2/M Phase Arrest of Acute Myeloid Leukemia KG1a and KG1 Cells].

OBJECTIVE: To investigate the effect of sulforaphane (SFN) on G2/M phase arrest of acute myeloid leukemia cells and its molecular mechanism. METHODS: KG1a and KG1cells were treated by different concentrations of SFN for 48 h. Flow cytometry (FCM) was used to analyze the phase distribution of cell cycle. High-throughput sequencing was used to detect the effect of SFN on the expression of cell cycle related genes in KG1a cells. The mRNA expression of P53, P21, CDC2 and CyclinB1 were detected by qPCR. The protein expression of P53, CDC2, P-CDC2 and CyclinB1 were detected by Western blot. RESULTS: Cells in the G2/M phase were increased from 11.9% to 54.0% in KG1a cells and 18.5% to 83.3% in KG1 cells after treated by SFN (8 µ mol / L) for 48 hours（P<0.001）. KEGG analysis indicated that P53 pathway was enriched in KG1a cells after treated by SFN. The heat-map graph showed that SFN could change the relevant genes of the cell cycle in KG1a cells. After SFN treatment, the mRNA level of P53 and P21 were significantly increased in KG1 and KG1a cells（P<0.05 or P<0.01）. The mRNA level of CDC2 showed a decrease trend with the increasing dose of SFN. At the dosage of 8 µmol /L, the mRNA expression levels of CDC2 was significantly lower than that in control group（P<0.05）. At the same time, the protein level of P53 was significantly increased in KG1 and kG1a cells after treated by SFN（P<0.05）. The protein level of CDC2 showed a decrease trend with the increasing dose of SFN in a dose manner（r=0.9482 and r=0.8977）. The protein levels of CDC2 in SFN 8 and 12 µ mol/L groups were significantly lower than that in control group(P<0.05, P<0.01). The protein levels of P-CDC2 was increased. But the change of mRNA and protein level of CyclinB1 was not significant. CONCLUSION: SFN induces leukemia cells to block in G2/M phase by activating P53 signaling pathway, which can inhibit the expression of CDC2 and the activity of CDC2/cyclinB1.

EPAS1 targeting by miR-152-3p in Paclitaxel-resistant Breast Cancer.

Background: Paclitaxel plays a pivotal role in the chemotherapy of breast cancer, but resistance to this drug is an important obstacle in the treatment. It is reported that microRNA-152-3p (miR-152-3p) is involved in tamoxifen resistance in breast cancer, but whether it is involved in paclitaxel resistance in breast cancer remains unknown. Materials and methods: We examined the expression of miR-152-3p in breast cancer tissues and cells by qRT-PCR. After transfecting paclitaxel-resistant MCF-7/TAX cells with miR-152-3p mimics, we analyzed the function of miR-152-3p in these cells by MTT assay and flow cytometry. We screened the target gene, endothelial PAS domain-containing protein 1 (EPAS1), using bioinformatics analysis and verified it with the dual luciferase reporter gene experiment. The relationship between EPAS1 and miR-152-3p and their roles in paclitaxel resistance of breast cancer were further investigated using RNA interference and transfection techniques. Results: The expression of miR-152-3p in normal breast tissues and cells was markedly higher than that in breast cancer. Overexpression of miR-152-3p decreased the survival rate and increased the apoptosis rate and sensitivity of MCF-7/TAX cells to paclitaxel. We confirmed that EPAS1 is the target of miR-152-3p and is negatively regulated by this miRNA. Moreover, transfection with EPAS1 siRNA enhanced the susceptibility and apoptosis rate of MCF-7/TAX cells to paclitaxel. Co-transfection of miR-152-3p mimics and EPAS1 increased paclitaxel sensitivity and apoptosis induced by the drug. Conclusion: miR-152-3p inhibits the survival of MCF-7/TAX cells and promotes their apoptosis by targeting the expression of EPAS1, thereby, enhancing the sensitivity of these breast cancer cells to paclitaxel.

Zebrafish Lacking Circadian Gene per2 Exhibit Visual Function Deficiency.

The retina has an intrinsic circadian clock, but the importance of this clock for vision is unknown. Zebrafish offer many advantages for studying vertebrate vision and circadian rhythm. Here, we explored the role of zebrafish per2, a light-regulated gene, in visual behavior and the underlying mechanisms. We observed that per2 mutant zebrafish larvae showed decreased contrast sensitivity and visual acuity using optokinetic response (OKR) assays. Using a visual motor response (VMR) assay, we observed normal OFF responses but abnormal ON responses in mutant zebrafish larvae. Immunofluorescence showed that mutants had a normal morphology of cone photoreceptor cells and retinal organization. However, electron microscopy showed that per2 mutants displayed abnormal and decreased photoreceptor ribbon synapses with arciform density, which resulted in retinal ON pathway defect. We also examined the expression of three cone opsins by quantitative real-time PCR (qRT-PCR), and the expression of long-wave-sensitive opsin (opn1lw) and short-wave-sensitive opsin (opn1sw) was reduced in mutant zebrafish larvae. qRT-PCR analyses also showed a down-regulation of the clock genes cry1ba and bmal1b in the adult eye of per2 mutant zebrafish. This study identified a mechanism by which a clock gene affects visual function and defined important roles of per2 in retinal information processing.

[Effects of Arsenic Trioxide on K562 Cell Proliferation and Its Mechanisms].

OBJECTIVE: To investigate the effects of arsenic trioxide (As2O3) on K562 cell proliferation by regulating cell cycle protein D1 and cyclin-dependent kinase inhibitor p27kip1. METHODS: MTT was used to detect the effect of As2O3 on K562 cell proliferation, so as to screen out the appropriate drug concentration. Furthermore, the K562 cell apoptosis was observed by microscopy. The expression of CyclinD1 and p27kip1 in K562 cells treated with As2O3 was analyzed by reverse transcription-polymerase chain reaction(RT-PCR), immunohistochemistry and Western blot. RESULTS: As2O3 could inhibit the proliferation of K562 cells in a dose- and time- dependent manner (r= 0.967). And the apoptosis cell number in As2O3 group was significantly higher than that in the control group(P<0.05). As2O3 could markedly inhibit the expression of CyclinD1 in K562 cells(P<0.05), but the expression of P27kip1 was not significantly changed after As2O3 treatment. CONCLUSIONS: As2O3 can induce K562 cell apoptosis and inhibit K562 cell proliferation by regulating the expression of CyclinD1.

[Mannan-Binding Lectin Inhibits Candida Albicans-Induced DC Maturation and Cytokine Secretion].

OBJECTIVE: To investigate the effects of mannan-binding lectin (MBL) on the maturation and cytokine secretion of human dendritic cells (DC) induced by Candida albicans (C. albicans). METHODS: The plastic-adherent mononuclear cells were prepared from the blood of healthy adult volunteers. The human peripheral blood mononuclear cells-derived dendritic cells (MNC-DC) were induced by 5-day-culture in medium supplemented with rhGM-CSF and rhIL-4, and then cultured for 2 days in presence or absence of C. albicans at varying concentration of human MBL ranging from 1 to 20 mg/L. DC's shape and characters were observed under inverted microscopy, the expression of CD83 and CD86 on DC was analyzed by FACS. The levels of TNF-α and IL-6 were detected by ELISA. FACS also was used to investigate the interaction of MBL with immature DC(imDC) and C. albicans. Western blot was used to detect C. albicans-induced IκBα phosphorylation and p65/NF-κB translocation in DC. RESULTS: MBL at higher concentrations (10-20 mg/L) down-regulated the expression of CD83 and CD86 on the monocyte-derived dentritic cells(MoDC) induced by C. albicans, and inhibited the production of TNF-α and IL-6 induced by C. albicans. FACS showed that MBL could not only bind to C. albicans but also bind to imDCs in a Ca2+-dependent manner. Western blot showed that MBL could decrease the phosphorylation of IκBα and the nuclear translocation of p65/ NF-κB. CONCLUSION: MBL may inhibit TNF-α and IL-6 production induced by C. albicans in DC through NF-κB signaling pathways, suggesting that MBL can play some roles in the regulation of C. albicans-induced immune response.

[Mechanism of MBL inhibiting the LPS-induced DC maturation].

The study was aimed to investigate the mechanism of mannan-binding lectin (MBL) on bacterial lipopolysaccharide (LPS)-induced human peripheral blood monocyte-derived dendritic cell (DC) maturation. The monocytes were prepared from the peripheral blood of healthy adult volunteers. The immature dendritic cells (imDC) were induced by 5-day-culture in medium supplemented with rhGM-CSF and rhIL-4. FACS was used to investigate the interaction of MBL with imDC and the impact of MBL on LPS binding to imDC. ELISA and Western blot was used to analyze the interaction of MBL with soluble TLR4 ectodomain protein (sTLR4); Western blot was used to detect LPS-induced NF-κB translocation in imDC. The results showed that MBL could directly bind to imDC in the presence of calcium. sTLR4 protein or LPS could competitively inhibit the binding of MBL to imDC. ELISA and Western blot showed that MBL could evidently bind to sTLR4 protein in a concentration-dependent manner. FACS showed that MBL could competitively inhibit the binding of LPS to imDC by binding to imDC directly. Western blot showed that MBL decreased LPS-induced NF-κB translocation in imDC. It is concluded that MBL may competitively inhibit the binding of LPS to imDC by binding to TLR4 expressed on imDC, resulted in inhibition of LPS-induced DC maturation, suggesting that MBL can regulate DC maturation through ligand-binding. This study provides the good foundation to clarify the mechanism of MBL inhibiting the LPS-induced DC maturation.

[Advances in the zebrafish circadian clock mechanisms].

Zebrafish has recently become an emerging vertebrate model for circadian studies. Here we summarized recent advances in the field of zebrafish circadian research. The characteristics and advantages of zebrafish as a circadian model, as well as its time-keeping mechanisms, were highlighted. Because light and temperature as external time cues both play important roles in the circadian regulation of zebrafish, we focused on recent studies concerning the effects of light and temperature on circadian clock genes and circadian regulatory pathways in zebrafish. We also provided the perspectives on prospective zebrafish circadian studies.

[The expression and significance of Notch1 in the human kidney tubular cell transdifferentiation induced by TGF-ß(1);].

AIM: To explore the dynamic expression and significance of Notch1 in the human kidney tubular epithelial cell transdifferentiation (KTECT)induced by TGF-ß(1);. METHODS: Normal human kidney epithelial cell line (HK-2) was cultured and then divided into blank group, and TGF-ß(1);(10 ng/mL) induced group. At the 12 h, 24 h, 48 h and 72 h, the morphologic changes of HK-2 cells were observed under an inverted phase contrast microscope. The expression of α-SMA, E-cadherin and Notchl as well as their mRNA were examined by immunohisto-chemistry staining and RT-PCR respictively. RESULTS: Compared with the normal control group, the expression levels ofα-SMA and Notchl markedly increased in TGF-ß(1); induced group (P<0.05), but the expression of E-cadherin obviously reduced(P<0.05). The expression of Notch1 protein and its mRNA was positively correlated to the expression ofα-SMA(r(protein);=0.958; r(mRNA);=0.944; P<0.05), and was negatively correlated to the expression of E-cadherin(r(protein);=-0.937; r(mRNA);=-0.921; P<0.05). CONCLUSION: Notch1 may participate in the KTECT induced by TGF-ß(1);.

[Influence of angiotensin-(1-7) on angiotensin II induced rat's tubular epithelial-myofibroblast transdifferentiation].

AIM: To explore the influence of angiotensin-(1-7)[Ang-(1-7)] on angiotension II(Ang II) induced rat's tubular epithelial-myofibroblast transdifferentiation and the secretion of extracellular matrix. METHODS: The NRK52E were maintained and sub-cultured treated with Ang-(1-7) (10(-6); mmol/L) and Ang II(10(-6); mmol/L) for 24, 48, 72, 96 hours, we detect the protein expressions of E-cadherin and α-SMA by immunocytochemistry method; The content of Col I and FN in the cultured supernatant were measured by ELISA; The mRNA expression of E-cadherin, α-SMA, Col I and FN was detected by real-time PCR. RESULTS: Treat with ang II 96 h, the protein and mRNA expression of E-cadherin decreased significantly (P<0.05), but the protein and mRNA expression α-SMA, col I and FN increased significantly (P<0.05); treat with Ang II and Ang-(1-7), the protein and mRNA expression of E-cadherin increased significantly (P<0.05), but the protein and mRNA expression α-SMA, col I and FN decreased significantly (P<0.05). CONCLUSION: Ang-(1-7) can inhibits Ang II-induced rat's tubular epithelial myofibroblast transdifferentiation and decrease the secretion of FN and Col I.

[Effect of Astragalus injection on the signal conduction of neonatal postasphyxial-serum induced human renal tubular cell injury].

OBJECTIVE: To investigate, from cytoprotein and molecular levels, the action mechanism of astragalus injection (ASI) on the signal conduction of human renal tubular cells (HK-2) injury induced by neonatal postasphyxial-serum (NPS), whether it is through activating the nuclear factor kappaB (NF-kappaB) signaling pathway. METHODS: Taking HK-2 as the target cell and the 20% NPS as the attacking factor, the experiment was conducted by dividing the target cells into two groups before attacking, the blank control group and the ASI pretreated group. The nuclear translocation of NF-kappaB was detected by confocal microscopy with indirect immunofluorescence stain, and the amount of NF-kappaB inhibitor subunit (I-kappaBalpha) was detected by Western blot before attacking. The detections were repeated at various time points in the experiment, i.e., 15 min, 1 h and 2 h after attacking, respectively. RESULTS: Before attacking, the nuclear translocation of NF-kappaB and the amount of I-kappaBalpha were not different in the two groups. But the former increased and the latter decreased significantly in the ASI group at all the time points after attacking with the topmost changes presented at 1 h after attacking, and significantly different to those in the control group at corresponding time CONCLUSION: ASI pretreatment could inhibit the activation of NF-kappaB induced by postasphyxial-serum.

[Interventional effects of emodin on transforming growth factor-beta1/integrin-linked kinase signal way in interleukin-1beta-induced transdifferentiation of rat tubular epithelial-myofibroblasts].

OBJECTIVE: To study the effects of transforming growth factor-beta1/integrin-linked kinase (TGF-beta1/ILK) signal way in interleukin-1beta (IL-1beta)-induced rat tubular epithelial-myofibroblast transdifferentiation (TEMT), and to investigate whether emodin inhibits IL-1beta-induced TEMT through the TGF-beta1/ILK signal way-dependent mechanism. METHODS: Normal rat kidney epithelial cell line (NRK52E) was used in this study. NRK52E cells were divided into blank control group, emodin control group, IL-1beta-induced group, emodin-inhibited group, SB431542 (TGF-beta 1 type I receptor blocker)-inhibited group, emodin plus SB431542-inhibited group, emodin-pretreated group and emodin-reversed group. After 48-hour culture, morphological changes of the NRK52E cells were observed by an inverted phase contrast microscope. The expressions of alpha-smooth muscle actin (alpha-SMA) and E-cadherin were detected by two-color immunohistochemical staining, while the expressions of TGF-beta1 and ILK were detected by one-color immunohistochemical staining. We also performed the imaging analysis to quantitatively analyze the result of the immunohistochemical staining. The secretion of fibronectin (FN) was analyzed by enzyme-linked immunosorbent assay. RESULTS: Compared with the blank control group, IL-1beta might induce TEMT, which was showed in increasing expression of alpha-SMA, increasing secreting of FN and decreasing expression of E-cadherin, and at the same time the expressions of TGF-beta1 and ILK were enhanced (P<0.05). Emodin might inhibit all of those changes induced by IL-1beta (P<0.05). When TGF-beta1 signal way was intercepted, IL-1beta induced-TEMT was suppressed and the expression of ILK was decreased, however, there was no significant difference in expression of TGF-beta1 between the SB431542 group and the IL-1beta-induced group. Compared with emodin-inhibited group, emodin-pretreatment could not prevent IL-1beta induced-TEMT in a certain extent, but emodin could not revert IL-1beta-induced TEMT. Spearman correlation analysis showed that TGF-beta1 expression had positive correlation with expressions of alpha-SMA, FN, ILK and negative correlation with E-cadherin expression, and the expression of ILK was positively correlated with the expressions of alpha-SMA and FN and negatively correlated with E-cadherin expression. CONCLUSION: IL-1beta induces TEMT partly depending on TGF-beta1/ILK signal way, partly via which emodin inhibits the TEMT induced by IL-1beta.

[Role of serum from asphyxiated neonates in the inducement of human renal tubular cell adhesion to neutrophils].

OBJECTIVE: To study the role of serum from asphyxiated neonates in the inducement of human renal proximal tubular epithelial cells (HK-2) adhesion to neutrophils and possible mechanisms. METHODS: HK-2 cells were cultured randomly with 20% serum from neonates (1, 3, and 7 days after asphyxia), pyrrolidine dithiocarbamate (PDTC) or placebo. The activity of myeloperoxidase (MPO), an indicator of adhesion ability of HK-2 cells to neutrophils in suspensions, was detected by the biochemistry assay. Intercellular adhesion molecule-1 (ICAM-1) and nuclear factor-kappaB (NF-kappaB) of HK-2 cells were examined with the immunohistochemical staining. RESULTS: The expression of MPO in the post-asphyxial 1-day serum treatment group were significantly higher than that in the PDTC treatment and the control groups as well as the post-asphyxial 3 and 7-day serum treatment groups (P<0.01). The expression of ICAM-1 and NF-kappaB in the post-asphyxial 1-day serum treatment group was also significantly higher than that in the other groups (P<0.01). CONCLUSIONS: Serum from asphyxiated neonates can induce HK-2 cell adhesion to neutrophils, possibly through activating NF-kappaB and increasing the synthesis and expression of ICAM-1 on the surface of renal tubular epithelial cells.

[Interventional effect of emodin on the expression of intergern linked kinase in tubular epithelial-myofibroblast transdifferentiation].

AIM: To observe the change of ILK expression in interleukin-1beta(IL-1beta)-induced tubular epithelial-myofibroblast transdifferentiation, and to investigate whether emodin inhibit IL-1beta-induced tubular epithelial-myofibroblast transdifferentiation through an intergern linked kinase-dependent mechanism. METHODS: Normal rat kidney epithelial cell line (NRK52E) was cultured and then divided into blank group, emodin control group, IL-1beta-induced group and emodin-inhibited group. When the cells were cultured for 48 h, their morphological changes were observed by an inverted phase contrast microscope. The expression of a-smooth muscle actin (a-SMA) and E-cadherin were detected using a two-color immunohistochemistry staining technique, while the expression of integrin-linked kinase (ILK) was detected using a one-color immunohistochemistry staining technique. The secretion of fibronectin (FN) was analyzed by ELISA. RESULTS: NRK52E cells cultured with IL-1 became fibroblast-like in appearance. The expression of a-SMA was enhanced (65h5+/-1h7 vs 140h4+/-3h0, P<0h05), the expression of E-cadherin was decreased (82h5+/-1h0 vs 36h0+/-2h8, P<0h05), the expression of ILK was enhanced (36h1+/-3h1 vs 82h4+/-1h2, P<0h05), and the secretion of FN was increased (54h6+/-3h1 vs 124h8+/-3h2 mg/L, P<0h05). Emodin markedly inhibited all of those changes induced by IL-1beta. CONCLUSION: The expression of ILK is up-regulated in IL-1beta-induced tubular epithelial-myofibroblast transdifferentiation. Emodin might inhibit TEMT by a down-regulation the expression of ILK.

[Gene cloning, optimized expression and immunogenicity evaluation of tetanus toxin fragment C].

OBJECTIVE: To obtain highly purified tetanus toxin fragment C (TTC) with good immunogenicity. METHODS: The gene fragment encoding TTC was amplified from Clostridium tetani plasmid DNA by PCR, inserted into the vector pET43.1a (+) and expressed in E. coli BL21(DE3)plysS. After purification using Ni2+-chelate affinity chromatography, the expressed fusion protein was digested by thrombin and the resultant TTC protein was purified with Ni2+-chelate affinity chromatography followed by identification with SDS-PAGE and Western blotting. The purifed TTC protein was then used to immunize mice to test its immunogenecity. RESULTS: The 1373-bp gene fragment encoding TTC was obtained, and the constructed recombinant expression vector pET43.1a (+)-TTC was successfully expressed in E. coli BL21(DE3)plysS. SDS-PAGE identified a recombinant fusion protein with relative molecular mass (Mr) of 117 000, which accounted for 22% of the total bacterial protein. The TTC protein with Mr of 50 000 was obtained after purification of the thrombin digestion products of the fusion protein, with a purity reaching 95.5%. Both the fusion protein and TTC protein could be recognized by anti-tetanus toxin antibody as shown by Western blotting. The titer of the anti-serum from mice immunized with the TTC protein was 1:25 600, and the anti-serum could specifically bind to tetanus toxin. CONCLUSION: Highly purified and immunogenetic TTC protein has been successfully obtained, which provides a good model antigen for studying antigen presentation and immune responses in vivo.

[Role and mechanism of Salvia miltiorrhiza Bunge in alleviating injury induced by hypoxia/reoxygenation in HK-2 cells].

OBJECTIVE: Salvia miltorrhiza Bunge (SMB) is a traditional Chinese herb, which is considered to promote blood flow and remove blood stasis. This study examined whether SMB can alleviate injury induced by hypoxia/reoxygenation (H/R) in human kidney proximal tubular cells-2 (HK-2 cells). METHODS: There were 3 experimental groups: control, H/R injury and SMB-treated H/R injury. H/R injury of HK-2 cells was induced by first covering the cells with and then removing liquid paraffin wax. Different concentrations of compound SMB solution (0.05%, 0.10%, 0.15% or 0.20%) were administered to the SMB-treated H/R injury group before the hypoxic injury. After 4, 12 and 24 hrs of hypoxia and 4, 12, 24 and 48 hrs of reoxygenation, morphologic changes of HK-2 cells were observed under an inverted microscope. Cell viability was measured by the MTT method. Lactate dehydrogenase (LDH) activity in the culture supernatants was assayed using biochemical methods; TNF-alpha levels were determined by radioimmunoassay (RIA). RESULTS: The number of HK-2 cells was significantly reduced in the H/R injury group after hypoxia, and reached a nadir 24 hrs after hypoxia treatment. Various concentrations of SMB-treated groups showed significantly greater number of HK-2 cells than the H/R injury group. SMB solution (0.10%) produced the best effect. The levels of LDH and TNF-alpha in the H/R injury group were significantly increased, and reached a peak between 24 hrs of hypoxia and 4 hrs of reoxygenation when compared to the control group. Pre-treating with 0.10% SMB resulted in significantly lower levels of LDH and TNF-alpha than in the untreated H/R injury group at various time points of H/R. CONCLUSIONS: SMB has protective effects against H/R injury of HK-2 cells, possibly through inhibition of inflammatory cytokines.

[Construction, expression and immunogenicity study of a chimeric MS/hIL-12 eukaryotic expression plasmid].

OBJECTIVE: To construct and express a chimeric Mtb8.4 with signal peptide (MS)/hIL12 eukaryotic expression plasmid, and to study the immunogenicity of the MS/hIL-12 chimeric genetic vaccines. METHODS: The MS/hIL-12 chimeric gene was amplified by polymerase chain reaction (PCR) and cloned into the eukaryotic expression vector pCI-neo. The correct pCI-neo-MS/hIL12 (pMSI) recombinant plasmid was identified by PCR, restricted enzyme digestion and DNA sequencing. COS-7 cells were transfected with pMSI constructs by cationic liposome. After 48 hours, mRNA of the target gene was detected by RT-PCR, and hIL-12 protein in culture supernatant and cell lysates was detected by Western blot. C57BL/6N mice were vaccinated with MS/hIL-12 chimeric gene vaccine for three times at 3 week intervals. Four weeks after the final inoculation, three mice were sacrificed for measurement of the cytokine response and cytotoxic T lymphocyte (CTL) induction. RESULTS: The accuracy of plasmid construction was confirmed by a number of molecular biological techniques. Transfection of COS-7 cells with plasmids pMSI lead to transient expression of fusion proteins. The IFN-gamma and IL-2 titers were (1,521 +/- 48) ng/L and (755 +/- 41) ng/L in MS/hIL-12 chimeric gene vaccine group, (820 +/- 50) ng/L and (297 +/- 31) ng/L in MS gene vaccine group, (1,487 +/- 40) ng/L and (767 +/- 50) ng/L in BCG group, (121 +/- 16) ng/L and (62 +/- 10) ng/L in vacant vector group, and (48 +/- 16) ng/L and (32 +/- 17) ng/L in PBS group respectively. The levels of IFN-gamma and IL-2 in MS/hIL-12 chimeric gene vaccine group were higher than those of MS gene vaccine group, vacant vector group and PBS group (P < 0.01) and was similar to the BCG group (P > 0.05). The level of IL-4 in BCG group [(91 +/- 11) ng/L] increased significantly as compared to other groups (P < 0.01). When effector-cell-to-target-cell ratio (E:T ratio) were 100:1, 50:1, and 10:1 respectively, the CTL activity was 77.5%, 51.2%, 30.3% in MS/hIL-12 chimeric gene vaccine group, 56.2%, 37.8%, 11.5% in MS gene vaccine group, 28.9%, 21.4%, 9.8% in BCG group. The cytotoxicity in MS/hIL-12 chimeric gene vaccine group was higher than that of other groups (P < 0.01). CONCLUSION: When used to construct the chimeric gene vaccine, hIL-12 could improve the immunogenicity of MS gene vaccine.

Chronic hepatitis B serum promotes apoptotic damage in human renal tubular cells.

AIM: To investigate the effect of the serum of patients with chronic hepatitis B (CHB) on apoptosis of renal tubular epithelial cells in vitro and to study the role of hepatitis B virus (HBV) and transforming growth factor-beta (1) (TGF-beta (1)) in the pathogenesis of hepatitis B virus associated glomerulonephritis (HBV-GN). METHODS: The levels of serum TGF-beta(1) were measured by specific enzyme linked immunosorbent assay (ELISA) and HBV DNA was tested by polymerase chain reaction (PCR) in 44 patients with CHB ,and 20 healthy persons as the control. The normal human kidney proximal tubular cell (HK-2) was cultured together with the sera of healthy persons, CHB patients with HBV-DNA negative (20 cases) and HBV-DNA positive (24 cases) for up to 72 h. Apoptosis and Fas expression of the HK-2 were detected by flow cytometer. RESULTS: The apoptosis rate and Fas expression of HK-2 cells were significantly higher in HBV DNA positive serum group 19.01%+/-5.85% and 17.58%+/-8.35%, HBV DNA negative serum group 8.12%+/-2.80% and 6.96%+/-2.76% than those in control group 4.25%+/-0.65% and 2.33%+/-1.09%, respectively (P<0.01). The apoptosis rate and Fas expression of HK-2 in HBV DNA positive serum group was significantly higher than those in HBV DNA negative serum (P<0.01). Apoptosis rate of HK-2 cells in HBV DNA positive serum group was positively correlated with the level of HBV-DNA (r = 0.657). The level of serum TGF-beta (1) in CHB group was 163.05+/-91.35 microg/L, significantly higher as compared with 81.40+/-40.75 microg/L in the control group (P<0.01). CONCLUSION: The serum of patients with chronic hepatitis B promotes apoptotic damage in human renal tubular cells by triggering a pathway of Fas up-regulation. HBV and TGF-beta (1) may play important roles in the mechanism of hepatitis B virus associated glomerulonephritis.

[Replication of a model of injury to human renal proximal tubular cells induced by hypoxia/reoxygenation].

OBJECTIVE: To replicate a new model of injury to human renal proximal tubular cells (HK-2) induced by hypoxia/reoxygenation. METHODS: Human renal proximal tubular cell line HK-2 cell was used as the target cell. Tubular cells were divided into six groups: 4 hours of hypoxia, 12 hours of hypoxia, 24 hours of hypoxia, and 24 hours of hypoxia followed by reoxygenation 4, 12 or 24 hours later groups. Each group was accompanied by a control group. Hypoxic culture conditions were produced by covering the culture with liquid paraffin. Trypan blue exclusion was used for cell count and cell viability. The activity of lactate dehydrogenase (LDH) in the culture medium was determined by biochemical method. RESULTS: After being challenged by hypoxia followed by reoxygenation, trypan blue exclusion rate was greater, cell count and cell viability were lower, and the activity of LDH was increased. It indicated that the destruction of integrity of cellular membrane was induced by ischemia/reperfusion injury, and the tubular cells may be injured irreversibly. CONCLUSION: A simple model of hypoxic injury of renal tubular cells is replicated by covering the culture cells with liquid paraffin.