Biomedical subjects

Jian-ping Gong

Publications and source records attributed to Jian-ping Gong.

17 recordsLinked to original sources

PubMed2006

hTERT/re-caspase-3 system induce apoptosis in hTERT-positive cancer cells.

Apoptosis induction is a promising approach for the treatment of human cancer. To achieve this purpose, the design of an expression system capable to induce apoptosis specifically in cancer cells is essential. Telomerase is an attractive target for delivery of apoptotic genes as an overwhelming majority of cancers have telomerase activity whereas most normal cells have low or an absence of telomerase activity. Activation of telomerase is tightly regulated at the transcriptional level of human telomerase reverse transcriptase (hTERT). In the present study, we developed a telomerase-specific delivery system of apoptosis-inducible gene re-Caspase-3, through utilizing the promoter of the hTERT gene, and then investigated its antitumor effect on cancer cells and tissues. The reason we used the re-Caspase-3 gene is that it is capable of autocatalytic processing and inducing apoptosis independent of the initiator Caspases. Here, we demonstrated that the hTERT/re-Caspase-3 system induced apoptosis in hTERT-positive cancer cells: CNE1 (nasopharyngeal carcinoma), HRT-18 (colonic carcinoma), MGC (stomath carcinoma), but not in hTERT-low Hacat (human normal keratinize epithelium) cells. In addition, the growth of s.c. tumors in nude mice was suppressed significantly by the treatment with the hTERT/re-Caspase-3 system. Results suggested that the telomerase-specific transfer of there-Caspase-3 gene may be an effective and promising targeting approach for the treatment of cancer.

Animals↗

PubMed2006

[The mechanism and treatment phases chosen of glycine for inhibition lipopolysaccharide induced Kupffer cells activation].

OBJECTIVE: To explore the possible mechanism and optimal treatment phase of glycine for inhibition lipopolysaccharide (LPS) induced Kupffer cells (KCs) activation. METHODS: The KCs were isolated from 40 BALB/c mice and divided into four groups: the endotoxin group, the prevention group, the early treatment group and the later treatment group (n = 10). The endotoxin group was treated with 10 mg/L LPS, and in the other three groups, glycine (1 mmol/L) was given 24 h before, or at 0 h or 4 h respectively after LPS stimulation. At 0 h, 1 h, 2 h, 6 h and 12 h after LPS stimulation, the mRNA levels and protein expression of interleukin-1 receptor associated kinase-4 (IRAK-4) were determined by reverse transcription polymerase chain reaction (RT-PCR) and Western blot respectively, and nuclear factor-kappaB (NF-kappaB) activities as well as tumor necrosis factor alpha (TNF-alpha) levels were also detected by enzyme-linked immunosorbent assay (ELISA). RESULTS: The climax values of IRAK-4, NF-kappaB and TNF-alpha were significantly higher in the endotoxin group and the later treatment group than that in the other two groups (t = 3.17, 4.33, 2.47, 126.73, P < 0.01). CONCLUSION: The results indicated that prophylactic or simultaneous treatment with glycine could effectively inhibit LPS-induced KCs activation by inhibiting IRAK-4 expression.

Animals↗

PubMed2006

Glycine blunts transplantative liver ischemia-reperfusion injury by downregulating interleukin 1 receptor associated kinase-4.

AIM: To determine whether glycine could downregulate interleukin 1 receptor associated kinase-4 (IRAK-4) expression to interfere with lipopolysaccharides (LPS) signal transduction and blunt transplantative liver ischemia-reperfusion injury (I/RI). METHODS: SD rats were randomly divided into two groups: donor animals of the glycine group (n=40) were given glycine (1.5 mL; 300 mmol/L, iv) 1 h before harvest, and the control group were treated with 1.5 mL physiological saline (n= 40). Orthotopic liver transplantation was then performed according to the Kamada technique. Ten animals in each group were followed up for 7 d after surgery to assess survival. The remaining animals in each group were divided into 3 subgroups (n=10) at 1h, 2 h and 6 h after portal vein reperfusion. Levels of LPS, serum aspartate aminotransferase (AST), alanine aminotransferase (ALT) and total bilirubin in portal circulation, as well as IRAK-4 and TNF-alpha expression, NF-kappaB transcriptional activity and morphological study of liver tissues were analyzed. RESULTS: Reperfusion resulted in a significant elevation of LPS concentrations in each group persisting to the end of our study. However, glycine, which led to improved survival rate and liver function, significantly alleviated liver parenchyma cell damage by downregulating IRAK-4, TNF-alpha expression and NF-kappaB transcriptional activity compared with the control group. CONCLUSION: Glycine can attenuate hepatic I/RI by downregulating IRAK-4 to interfere with LPS signal transduction.

Animals↗

PubMed2006

[Expression changes of interleukin-1 receptor associated kinase-4 during endotoxin tolerance development in kupffer cells].

OBJECTIVE: To explore the mechanism of endotoxin tolerance (ET) through observing the expression of interleukin 1 receptor associated kinase-4 (IRAK-4) during endotoxin tolerance development in Kupffer cells (KCs). METHODS: Isolated KCs of Balb/c mouse were divided into two groups: the non-endotoxin tolerance (NET) group and the endotoxin tolerance (ET) group, which were pretreated with 10 ng/ml lipopolysaccharide (LPS) for 24 h. Then, the two groups were treated with 100 ng/ml LPS. The expressions of IRAK-4 gene and protein level were determined by RT-PCR and Western blot. The activities of NF-kappaB of KCs and the TNFalpha level were estimated by ELISA at 0 h, 1 h, 3 h, 6 h and 12 h after LPS stimulation. RESULTS: The ultimate level of IRAK-4, the activities of NF-kappaB and the TNFalpha level were evidently lower in the ET group than those in the NET group (t = 12.4, 17.4 and 138.9 respectively, P<0.01). CONCLUSIONS: Pretreatment with LPS on KCs could induce endotoxin tolerance of KCs and inhibition of IRAK-4 expression may be one of the reasons for its development.

Animals↗

PubMed2006

[The protection mechanisms of glycine against liver injury induced by lipopolysaccharides].

OBJECTIVE: To explore the protective mechanisms of glycine (Gly) on lipopolysaccharides (LPS) induced liver injury. METHODS: BABL/c mice were randomly divided into a LPS group, in which the animals were intraperitoneally injected with 10 mg/kg LPS, and a Gly group, in which the mice were pretreated with a 5% Gly-containing diet for 3 days before receiving the same dose of LPS. The livers of the mice were examined for histopathological changes. The TNF alpha and interleukin-10 (IL-10) levels in the blood plasma were measured using ELISA analysis. The mRNA expression of TNF alpha, IL-10 and Toll-like receptor 4 (TLR4) in hepatic tissues were detected using RT-PCR analysis. Protein expression of TLR4 in livers was detected using immunohistochemistry. RESULTS: The Gly group mice had an improved survival rate and attenuated LPS-induced pathological changes in the liver tissues in comparison with those of the LPS group animals. The TNF alpha levels [(1,852.80+/-126.64) pg/ml vs (708.83+/-51.29) pg/ml, P<0.05] in plasma, as well as the expression of TNF alpha (A 1.59+/-0.14 vs. 0.91+/-0.11, P<0.05) and TLR4 (A 0.97+/-0.12 vs. 0.53+/-0.11, P<0.05) mRNA in liver tissues were decreased. However, the levels of plasma interleukin-10 [(344.09+/-31.70) pg/ml vs (418.64+/-38.86) pg/ml, P<0.05] were significantly increased and the peaking time left, shifted. CONCLUSIONS: Gly pretreatment could attenuate LPS -induced liver injury in mice, which may be associated with its role in down-regulating TLR4 expression and up-regulating IL-10 production.

Animals↗

PubMed2006

[The influence with block the endotoxin signal transduction for ischemia/reperfusion injury of graft liver in rats].

OBJECTIVE: To explore the feasibility of interleukin 1 receptor associated kinase-4 (IRAK-4) as gene therapy target for liver ischemia/reperfusion injury (I/RI) and effective approach in vivo for short hairpin RNA (shRNA) interference used to gene therapy in liver graft hqappened. METHODS: Sprague-Dawley rats were randomly divided into three groups: the control group, the in vivo transfection group (IVT) and the cold ischemia transfection group (CIT). Experiments of orthotopic liver transplantation were performed by two-cuff method. CIT were perfused with IRAK-4-shRNA plasmid (pSIIRAK-4) during cold ischemia phase, IVT received the equivalent volumes (2 mL) of pSIIRAK-4 after portal vein inosculated, and the control group leaved without any treatment. At 0 min, 60 min and 180 min after reperfusion, the expression of IRAK-4 gene and protein level were determined by RT-PCR and Western blot. The serum TNF-alpha level was detected by ELISA. Liver histopathological changes and cell apoptosis were observed by electron microscope and TUNEL. RESULTS: After reperfusion, the expression of IRAK-4 were largely depressed in CIT than that of IVT and the control group (P < 0.01), and furthermore, the serum TNF-alpha level, proportion of hepatocyte apoptosis and severity of hepatocyte injury were also lower than the latter. CONCLUSION: These results indicate that depression IRAK-4 expression with IRAK-4-shRNA through portal vein perfusion during cold ischemia phase could effectively blunt graft hepatic I/RI.

Animals↗

PubMed2006

[Endoscopy-assisted internal fixation of ramus and subcondylar fracture].

OBJECTIVE: To investigate clinical application of endoscopy-assisted internal fixation of ramus and subcondylar fractures. METHODS: In 11 patients with mandibular ramus and subcondylar fractures, endoscopy-assisted internal fixations with titanium plates were performed using micro-angular drill and screwdriver. RESULTS: All of the patients showed no visible facial scars. Orthorpantography and three dimensional reconstructions of spiral CT scan demonstrated that all fractures were healed 1 to 15 months after operation. Slight malocclusion existed in 1 case and slight limited mouth openings were found in 2 cases. CONCLUSIONS: Endoscopy-assisted internal fixation of mandibular ramus and subcondylar fracture avoided visible facial scars and the risk of facial nerve damage, it is, therefore, a minimally invasive and effective procedure.

Adult↗

PubMed2005

[Expression of CD14 and Toll-like receptor 4 on Kupffer cells and its role in ischemia-reperfusion injury on rat liver graft].

OBJECTIVE: To study the expression of lipopolysaccharide (LPS) receptor CD14 and Toll-like receptor 4 (TLR4) on Kupffer cells and its role in ischemia-reperfusion injury (IRI) on rat liver graft. METHODS: The Kupffer cells following IRI were isolated and divided into control, ischemia-reperfusion (IR), and anti-CD14 antibody group. The mRNA and protein expression of CD14 and TLR4, nuclear factor kappa B (NF-kappaB) activity and TNF-alpha level in supernatant were measured. RESULTS: The mRNA and protein expression of CD14 and TLR4 in IR group were significantly higher than those in control group (P < 0.01). The NF-kappaB activity and TNF-alpha level in IR group were significantly higher than those in control group (P < 0.01), and they greatly decreased after anti CD14 antibody treatment (compared with IR group, P < 0.05), but were still significantly higher than those in control group (P < 0.01). CONCLUSIONS: LPS following IRI could up-regulate CD14 and TLR4 gene and protein expression on Kupffer cells, and subsequently activate NF-kappaB to produce cytokines, but other signal transduction pathways might also participate in the IRI.

Animals↗

PubMed2005

[The effect of glycine on CD14 and NF-kappa B in Kupffer cells from rat liver grafts after ischemia-reperfusion injury].

OBJECTIVE: To investigate the effect of glycine on CD14 and NF-kappa B in Kupffer cells from rat liver grafts after ischemia-reperfusion injury (IRI). METHODS: The rats were randomly divided into an IRI group, saline solution preconditioning group, and glycine preconditioning group. Their survival rates, graft functions, and hepatic histopathologic examinations were observed after IRI. Kupffer cells (KCs) following IRI were isolated and cultured to detect CD14 mRNA, NF-kappa B binding activity, and the TNF alpha and IL-1 level in the supernatant of the media. RESULTS: (1) Glycine preconditioning greatly enhanced the one-week survival rate (chi2 = 6.67 and 8.57 respectively), improved graft function, and ameliorated the histopathologic signs of injury. (2) The CD14 mRNA expression level (F = 7.64), NF-kappa B binding activity (F = 11.47), TNF alpha and IL-1 production (F = 14.08 and 9.56 respectively) in the glycine group were significantly lower than those in the other two groups. CONCLUSION: Glycine could efficiently protect rat liver grafts from ischemia-reperfusion injury by repressing the expression of CD14 and NF-kappa B binding activity in Kupffer cells and inhibiting the productions of TNF alpha and IL-1.

Animals↗

PubMed2005

[Expression of CD14 protein in U937 cells induced by vitamin D3].

AIM: To observe the 1, 25-dihydroxy vitamin D3 (Vit D3) induced CD14 expression in human U937 cell line and the reaction of the cells to LPS stimulation following the induction. METHODS: U937 cells were cocultured with 0.1 mumol/L Vit D3 for 24 hours to induce the expression of CD14 gene and the sensitiveness of U937 cells to stimulation of LPS at various concentrations and for different times were observed. RESULTS: Vit D3 stably induced U937 cells to express CD14 mRNA and CD14 protein. The sensitivity of U937 cells to LPS stimulation increased notably after Vit D3 induction. It was demonstrated that low concentration of LPS stimulated the activation of NF-kappaB in U937/CD14 cells, and enhanced the transcription and expression of TNF-alpha gene, and even release of TNF-alpha into the culture supernatant. CONCLUSION: Vit D3 can induce U937 cells to express CD14 gene and CD14 protein and enhance the reactivity of U937/CD14 cells to LPS stimulation.

Animals↗

PubMed2005

[An experimental study of the inhibitory effects on the activation of endotoxin-induced Kupffer cells through short hairpin RNA targeting interleukin-1 receptor associated kinase-4 gene].

OBJECTIVE: To explore the inhibitory effects on the activation of endotoxin-induced Kupffer cells (KCs) through short hairpin RNA (shRNA) targeting interleukin-1 receptor associated kinase-4 (IRAK-4) gene. METHODS: Two effective transfection shRNA plasmid (pSIIRAK-4-A, pSIIRAK-4-B) and one invalidated plasmids (pSIIRAK-4-C) targeting IRAK-4 gene were constructed. The isolated mouse KCs were divided into three groups: the normal control group, the RNAi control group (pSIIRAK-4-C) and the RNAi effective group (pSIIRAK-4-A, pSIIRAK-4-B). Then KCs were stimulated with 0.1 microg/ml lipopolysaccharide (LPS) after 24 h transfection with the constructed plasmid. The expression of IRAK-4 gene and protein level were determined by RT-PCR and Western blot at 6 h after LPS stimulation, and the activities of NF-kappaB in KCs and the TNFalpha level were estimated by ELISA at 0 h, 1 h, 3 h, 6 h and 12 h. RESULTS: The level of IRAK-4, the activities of NF-kappaB and the TNF-alpha level in the RNAi effective group were evidently lower than those in normal and RNAi control groups (P < 0.01) at 1 h, 3 h, and 6 h. Especially, the pSIIRAK-4-A group in which the changes of the above indices were of no difference (P > 0.05), had better inhibited effects than that of the pSIIRAK-4-B group (P < 0.01). CONCLUSION: The shRNA targeting IRAK-4 gene could effectively inhibit the activation of endotoxin-induced KCs.

Animals↗

PubMed2004

Peplomycin induces G1-phase specific apoptosis in liver carcinoma cell line Bel-7402 involving G2-phase arrest.

AIM: To investigate the mechanism of peplomycin (PEP)-induced apoptosis in liver carcinoma cell line (Bel-7402). METHODS: Growth inhibition by PEP was analyzed using 3- 4,5-Dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT) assay. Apoptotic cells were detected using Hoechest 33258 staining, and confirmed by flow cytometric analysis and DNA fragmentation analysis. The expression of cyclin A and B1 were determined by flow cytometry and Western blot. Annexin V assay was measured by flow cytometric analysis. RESULTS: PEP induced apoptosis and then inhibited cell proliferation in liver carcinoma cell line Bel-7402. Cells treated with PEP 50 mumol/L for 15 h were arrested in G2-phase with dramatical expression of cyclin A and a little change in cyclin B1. Almost all the apoptosis occurred in cells undergoing the G1-phase after treatment for 24 h. CONCLUSION: Peplomycin induced G1-phase specific apoptosis in Bel-7402 involving G2-phase arrest.

Antibiotics, Antineoplastic↗

PubMed2004

[Study on ligustrazine in reversing multidrug resistance of HepG2/ADM cell in vitro].

OBJECTIVE: To study the reverse effect of ligustrazine (TMP) on HepG2/ADM, a herd of hepatocellular carcinoma cell, multidrug resistance (MDR) and the influence of P-gp170 expression. METHOD: The reverse effect of ligustrazine on HepG2/ADM cell was observed, with the methods of cell culture, MTT's analyze, RT-PCR and Flow cytometric, etc. RESULT: Ligustrazine could make MDR of cell line of HepG2/ADM reduce the expression of P-gp170, enhance the density of adriamycin in cell and increase the adriamycin's cytotoxicity. With the Flow cytometric, the results of RT-PCR showed the transcriptional activity of the MDR1 decreased. CONCLUSION: Ligustrazine can reverse MDR of HCC cell line of HepG2/ADM and has prospect in clinical use.

ATP Binding Cassette Transporter, Subfamily B↗

PubMed2003

[The relationship between ATM gene silence inducing apoptosis susceptibility and abnormal CDK activity].

OBJECTIVE: To explore the molecular elements responsible for the enhanced apoptotic susceptibility in U937 cells mediated by silencing atactic telangiectasis mutation (ATM) gene. METHODS: Two U937 cell mutants, U937-ASPI3K (ATM gene negative) and U937-pZEOSV2 (+) (ATM gene positive) were used as a cell model system. Apoptosis was examined by measuring free nucleosome concentrations in U937 cells. Western blotting was employed to measure nuclear protein abundances of cdc25A, cdc25B, cdc25C, total p34cdc2, p34cdc2 (Thr161) or p34cdc2 (Thr14, Tyr15). RT-PCR was used to estimate cdc25 transcript levels. RESULTS: U937-ASPI3K exhibited an enhanced apoptotic susceptibility to lower dosage of irradiation, which could not be blocked by protein synthesis inhibitor. Protein serine-theronine phosphatase inhibitor or cyclin-dependent kinase (CDK) inhibitors could abolish the enhancement. Upon irradiation, p34cdc2 in U937-pZEOSV2 (+) was in an inactive state owing to phosphorylation of Thr 14 and Tyr15, which was associated with a dramatic decrease of nuclear cdc25A, cdc25B and cdc25C poteins. In contrast, p34cdc2 in U937-ASPI3K was in an active state owing to the low phosphorylation of Thr14 and Tyr15, which was associated with constant nuclear cdc25A, cdc25B and cdc25C protein abundance before and after irradiation. The responsive decrease of nuclear cdc25 proteins occurred at the post-transcription level. CONCLUSION: Silencing ATM gene blocks the irradiation induced responsive decrease of nuclear cdc25 proteins, resulting in an abnormal activation p34cdc2 is the critical molecular mechanism for the enhanced apoptotic responses.

Apoptosis↗

PubMed2003

In vivo expression of lipopolysaccharide binding protein and its gene induced by endotoxin.

OBJECTIVE: To investigate the expression of lipopolysaccharide binding protein (LBP) and its gene in rats with endotoxemia and explore the role of LBP in the response of host to endotoxin. METHODS: Thirty Wistar rats were divided randomly into five groups: the normal group and the endotoxemia groups (1, 3, 6, 12 hours after LPS injection, respectively). The level of plasma endotoxin was determined by the Limulus Amebocyte Lysate assay. The expression of LBP mRNA in hepatic tissue was examined by reverse transcription polymerase chain reaction (RT-PCR). Plasma levels of LBP, tumor necrosis factor (TNF)-alpha and interleukin (IL)-6 were measured by enzyme-linked immunosorbent assay (ELISA). Morphologic changes of hepatic tissue were observed under transmission electron microscope. RESULTS: The level of plasma endotoxin peaked at 1 h after LPS injection, then declined, but was still higher than that of the normal group at 12 h; intrahepatic expression of LBP mRNA and plasma LBP increased with time after LPS stimulation; TNF-alpha and IL-6 in plasma increased with upregulation of LBP expression; there were significant differences between the normal group and endotoxemia groups (P<0.05). Activation of Kupffer cells and injury of hepatocytes could be seen in rats with endotoxemia. CONCLUSIONS: LPS can upregulate the intrahepatic expression of LBP mRNA and increase the plasma LBP level. Under certain conditions, LBP may enhance the sensitivity of host to the toxic effects of LPS.

Acute-Phase Proteins↗

PubMed2003

[The role of cyclooxygenase 2 and prostaglandin I2 in the development of portal hypertensive gastropathy].

OBJECTIVES: To study the role of cyclooxygenase 2 (COX 2) and prostaglandin I2 (PGI2) in the development of portal hypertensive gastropathy (PHG). METHODS: Forty Wistar rats were divided into surgery group (32) and control group (8). Partial portal vein ligation method was used to narrow the sectional area of portal vein to establish the experimental model of PHG in surgery group rats. Then they were divided into four groups (8 rats in each). The free pressure of portal vein was determined at the 1st, 2nd, 3rd, 4th weeks after the operation, and 8 rats were killed to observe the pathological change of gastric mucosa. The levels of 6-keto-PGF1 alpha, a stable metabolite of PGI2, were determined by radioimmunoassay in gastric mucosa homogenate and the blood of portal vein. The expression of COX 2 in gastric mucosa was determined by immunohistochemistry. RESULTS: The free pressure of portal vein increased rapidly after partial portal vein ligation and maintained a high stable level after 1 week. They were (2.40+/-0.15) kPa, (2.38+/-0.17) kPa, (2.52+/-0.21) kPa, and (2.46+/-0.17) kPa at the 1st, 2nd, 3rd, and 4th weeks after partial portal vein ligation, while it was (0.90+/-0.16) kPa in control group (t>or=17.356, P<0.05). The gastric mucosa appeared pale, edema, hyperaemia, surface erosion, punctate hemorrhage and these lesions were more apparent with the time after the operation. The pathological examination showed that the gastric mucosa and submucosa thickened. The vessels of gastric mucosa and submucosa expanded and increased. There were lymphocytes and neutrophils infiltration around the vessels in the gastric mucosa and submucosa. The 6-keto-PGF1 alpha levels in gastric mucosa and the blood of portal vein increased rapidly and maintained a high level after partial portal vein ligation,which were higher than those in control group (104.52pg/ml+/-25.11pg/ml vs 73.62pg/ml+/- 20.33pg/ml, t=2.710, P<0.05; 180.21pg /ml+/-37.56pg /ml vs 142.11pg /ml+/-31.51pg /ml, t=2.198, P<0.05). The results of immunohistochemistry showed that the intensity and degree of the COX 2 staining in gastric tissue increased at the 1st, 2nd, 3rd, 4th weeks after partial portal vein ligation, while the COX 2 in control group rats was negative. CONCLUSIONS: The expression of COX 2 and PGI2 in gastric tissue increased in portal hypertension. PGI2 as an inflammatory medium, damages the gastric mucosa by expanding vessels and other mechanisms in portal hypertension. It may be one of the important factors contributing to the development of PHG.

Animals↗

PubMed2002

[Quantitative analysis of cell cyclin E expression threshold].

BACKGROUND & OBJECTIVES: It is important to analyze the threshold of cyclins when we research the mechanism of cell cycle progressing. However, there was no effective way to caculate quantitatively. This study was designed to analyze cyclin E expression threshold quantitatively. METHODS: MOLT-4 cells were detected at different photomultiplier tube (PMT) voltage by cyclin E/DNA multiparameter flow cytometry. Using this method, MOLT-4 cells were detected at the same voltage after being treated with caffeine and cycloheximide (CHX), and then MOLT-4 cells and JURKAT cells were detected at the same voltage. Threshold of cyclin E was counted by using formula B2/A x C (A, B, C indicates the minimum, threshold, and maximum of cyclin E fluorescence intensity respectively). RESULTS: Cyclin E threshold of MOLT-4 cells calculated by formula B2/A x C was invariable at different voltage. It decreased when cells treaded with caffeine and unchanged when treated with cycloheximide. At the same time, cyclin E threshold of JURKAT cells calculated by formula was much lower than that of Molt-4 cells. CONCLUSIONS: Formula B2/A x C can be used to analyze cyclin E expression threshold quantitatively.

Caffeine↗