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Biomedical subjects

Hong Ren

Publications and source records attributed to Hong Ren.

At least 19 recordsLinked to original sources
PubMed2026

Genomic and transcriptomic features of HBV integration in treatment-naïve, HBeAg-positive children with chronic HBV infection.

BACKGROUND: Hepatitis B virus (HBV) integration represents a major obstacle to curing HBV; however, the landscape of HBV integration and local immune response to transcriptionally active viral integration in children with chronic HBV infection remain unclear. Herein, we aimed to elucidate this landscape in this population. METHODS: Genomic analyses using a probe-based capture strategy were performed on 18 children and 28 adults with chronic HBV infection. Spatial transcriptomics (ST) was performed on 12 children from our cohort and 3 adults from a public database. FINDINGS: All patients were hepatitis B e antigen (HBeAg)-positive and treatment-naïve. Genomically, children exhibited significantly lower clonal expansion level of HBV-integrated hepatocytes than adults, despite comparable unique breakpoint counts. After adjusting for confounding variables, age was identified as an independent risk factor for total frequency of unique integration breakpoints (b = 3.22, P = 0.005). Spatially, ST revealed that spots with transcriptionally active viral integration exhibited a sparse distribution and accounted for a low proportion of all spots in children. Notably, at these spots, children showed reduced adaptive immune cells (e.g., CD8+ T cells) but increased innate components (myeloid cells, Kupffer cells, activated dendritic cells) and APC co-stimulation, whereas adults exhibited a uniform reduction of immune cell populations. INTERPRETATION: Compared with adults, children exhibit lower clonal expansion of HBV-integrated hepatocytes and distinct immune profiles in response to transcriptionally active viral integration, offering new insights into their differing clinical course. FUNDING: Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education).

Humans↗
PubMed2006

A DNA vaccine against chimeric AFP enhanced by HSP70 suppresses growth of hepatocellular carcinoma.

Alpha-fetoprotein (AFP) is produced principally in fetal liver, gastrointestinal tract and the yolk sac which is temporarily present during embryonic development. AFP is overexpressed in the majority of hepatocellular carcinoma (HCC) and thus offers an attractive target for immunotherapy against this neoplasm. Here, we report that anti-HCC effects were achieved in a therapeutic setting with a DNA vaccine encoding mouse AFP and co-expressing heat shock protein 70 (HSP70) gene. We also demonstrated that this vaccine elicited a marked and highly effective AFP specific CTL response against AFP-positive target cells. This vaccine also induced the prolongation of life span in mice bearing the tumor and the eradication of HCC. It is anticipated that vaccine strategies such as this may contribute to the effective future treatment of hepatocellular carcinoma.

Animals↗
PubMed2006

Protein phosphatase 6 down-regulates TAK1 kinase activation in the IL-1 signaling pathway.

TAK1 (transforming growth factor beta-activated kinase 1) is a serine/threonine kinase that is a mitogen-activated protein kinase kinase kinase and an essential intracellular signaling component in inflammatory signaling pathways. Upon stimulation of cells with inflammatory cytokines, TAK1 binds proteins that stimulate autophosphorylation within its activation loop and is thereby catalytically activated. This activation is transient; it peaks within a couple of minutes and is subsequently down-regulated rapidly to basal levels. The mechanism of down-regulation of TAK1 has not yet been elucidated. In this study, we found that toxin inhibition of type 2A protein phosphatases greatly enhances interleukin 1 (IL-1)-dependent phosphorylation of Thr-187 in the TAK1 activation loop as well as the catalytic activity of TAK1. From proteomic analysis of TAK1-binding proteins, we identified protein phosphatase 6 (PP6), a type-2A phosphatase, and demonstrated that PP6 associated with and inactivated TAK1 by dephosphorylation of Thr-187. Ectopic and endogenous PP6 co-precipitated with TAK1, and expression of PP6 reduced IL-1 activation of TAK1 but did not affect osmotic activation of MLK3, another MAPKKK. Reduction of PP6 expression by small interfering RNA enhances IL-1-induced phosphorylation of Thr-187 in TAK1. Enhancement occurred without change in levels of PP2A showing specificity for PP6. Our results demonstrate that PP6 specifically down-regulates TAK1 through dephosphorylation of Thr-187 in the activation loop, which is likely important for suppressing inflammatory responses via TAK1 signaling pathways.

Cells, Cultured↗
PubMed2006

Alkylene tether-length dependent gamma-aminobutyric acid type A receptor competitive antagonism by tacrine dimers.

Bis(7)-tacrine was previously demonstrated as an antagonist of gamma-aminobutyric acid type A (GABA(A)) receptors. In this study, the effects of a series of alkylene-linked tacrine dimers on GABA(A) receptors were examined. In radioligand binding assay, the analogues differed in binding affinity for GABA(A) receptors, and potency monotonically increased as the tether was shortened from nine to two methylenes. Bis(2)-tacrine, the shortest tacrine dimer, could displace [(3)H]muscimol from rat brain membranes with an IC(50) of 0.48 microM, which was 11, 13 and 525 times more potent than the GABA(A) receptor antagonist (+)-bicuculline, bis(7)-tacrine and tacrine, respectively. In whole-cell patch-clamp recordings, these dimeric tacrine analogues competitively antagonized GABA-induced inward current with a rank order of potency of bis(2)-tacrine>bicuculline>bis(7)-tacrine>bis(9)-tacrine>tacrine, and the potency of bis(2)-tacrine was 11, 18 and 487 times higher than that of (+)-bicuculline, bis(7)-tacrine and tacrine, respectively. Bis(2)-tacrine shifted the GABA concentration-response curve to the right in a parallel manner, and the inhibition was voltage-independent between -80 and +20 mV. It can be concluded that the shorter the alkylene linkage in tacrine dimers the stronger the binding affinity and higher the antagonistic effect on the GABA(A) receptor will be.

Alkylation↗
PubMed2006

[Association of single nucleotide polymorphism of megsin gene with IgA nephropathy].

OBJECTIVE: To investigate whether the single nucleotide polymorphisms (SNPs) in the gene of megsin, a novel serine protease inhibitor, account for the pathogenicity of IgA nephropathy (IgAN). METHODS: A comprehensive megsin gene survey, including the entire coding region, part of the regulatory region, and exon-intron connection region, was performed by PCR-direct sequencing on the DNA samples of peripheral blood from 12 randomly selected IgAN patients and 12 randomly selected healthy persons. Eight SNPs with moderate or high frequencies (with the frequency > 5%) selected from the 11 SNPs found were used as candidate SNPs. Then 210 IgAN patients proven by renal-biopsy, all of Chinese Han nationality, and 103 normal volunteers were recruited. The 8 candidate SNPs were genotyped by direct sequencing or PCR-RFLP and a case-control association study was carried out. RESULTS: The SNP of 267G/A in 5'untranslated region within exon1 was significantly associated with IgAN. The frequency of AG/AA genotype of the IgA patients was 29.0%, significantly higher than that of the controls (16.5%, P < 0.05). The frequency of A allele of the IgA patients was 14.8%, significantly higher than that of the controls (8.7%, P < 0.05). The odds ratio of AG/AA genotype versus GG genotype was 2.07 with the 95% confidence interval of 1.15 - 3.74. The linkage disequilibrium between two SNPs existed commonly within one gene. CONCLUSION: 267G/A in megsin gene is associated with IgAN susceptibility. AG and AA genotypes are the risk factors of pathogenesis of IgAN.

Adolescent↗
PubMed2006

Identification of a regulatory autophosphorylation site in the serine-threonine kinase RIP2.

Receptor-interacting protein 2 (RIP2) is a serine-threonine kinase that mediates signaling for many receptors of the innate and adaptive immune systems. Toll like receptors (TLR) are an important component of the innate immune response. Stimulation of RIP2-deficient cells with ligands for TLR 2, 3 and 4 results in impaired cytokine production and decreased activation of NF-kB and MAP kinases compared to wild-type cells. Stimulation of TLR 4 with its ligand lipopolysaccaride (LPS) leads to the activation of RIP2 kinase activity and its autophosphorylation. Here we identify serine residue 176 as a site of autophosphorylation using a combination of mass spectrometry and mutational analysis. Mutation of S176 to alanine not only abolishes autophosphorylation of RIP2 but also significantly decreases its catalytic activity. A phospho-specific anti-S176 antibody detects wild-type RIP2 but not kinase-dead RIP2 or the RIP2 S176A mutant. Endogenous RIP2 in THP-1 cells and mouse bone marrow derived macrophages can be detected by the phospho-RIP2 (S176) antibody only after stimulation with LPS suggesting that the antibody recognizes activated RIP2. In summary, our results indicate that S176 is a regulatory autophosphorylation site for RIP2 and that S176 phosphorylation can be used to monitor the activation state of RIP2.

Amino Acid Sequence↗
PubMed2006

Analysis of variabilities of serum proteomic spectra in patients with gastric cancer before and after operation.

AIM: To study the variabilities of serum proteomic spectra in patients with gastric cancer before and after operation in order to detect the specific protein markers that can be used for quick diagnosis of gastric cancer. METHODS: Proteomic spectra of 46 serum samples from patients with gastric cancer before and after operation and 40 from normal individuals were generated by IMAC-Cu protein chip and surface-enhanced laser desorption/ ionization time of flight mass spectrometry. RESULTS: Fourteen differentially expressed proteins in serum were screened by analysis of proteomic spectra of preoperative patients and normal individuals. We obtained 4 proteins (heat shock protein 27, glucose-regulated protein, prohibitin, protein disulfide isomerase A3) making up marker pattern which was able to class the patient-team and normal-team. These marker patterns yielded 95.7% sensitivity and 92.5% specificity, respectively. The proteins over-expressed in serum of preoperative patients were obviously down-regulated. CONCLUSION: Specific protein markers of gastric cancer can be used for the quick diagnosis of gastric cancer and judgment of prognosis. SELDI-TOF-MS is a useful tool for the detection and identification of new protein markers in serum.

Biomarkers, Tumor↗
PubMed2006

Novel vaccines for the treatment of chronic HBV infection based on mycobacterial heat shock protein 70.

Immunogenic peptide-based vaccines can raise significant cellular immune responses. Although cytotoxic T lymphocytes (CTL) peptide epitopes are generally poor immunogens, heat shock protein 70 from Mycobacterium tuberculosis (TBhsp70) can overcome this problem since it is a potent adjuvant that links innate and adaptive immune responses. Our goal is to use TBhsp70 as an adjuvant for development of therapeutic vaccines for chronic Hepatitis B virus infection (HBV). To this end, we genetically fused the HBV core 18-27 peptide (HBcAg((18-27))) as a CTL epitope to the C-terminus of TBhsp70 and expressed the resulting protein in methylotropic yeast Pichia pastoris GS115. At the same time, the TBhsp70-HBcAg((18-27)) peptide complex was reconstituted in vitro. We investigated whether TBhsp70-peptide complex and TBhsp70-peptide fusion protein could generate antigen specific CTL responses in vitro. Dendritic cells (DC) from HLA-A2(+) chronic HBV infection and healthy control pulsed with two vaccines were studied phenotypically by FACS analyses and functionally by cytokine release, and HBV-specific CTL response. Our results demonstrate that two vaccines can activate DC of chronic HBV infection and healthy control by upregulation CD40 and CD86, high production of IL-12p70 and TNF-alpha. Furthermore, autologous T cells with DC stimulated by two vaccines can produce IFN-gamma and generate HBV-specific CTL response. However, capacity for CTL response and cytokines production from HBV infections remained inferior to that of healthy controls. Thus, the strategy of utilizing TBhsp70 may provide a novel design for the development of prophylactic and therapeutic vaccines.

Adolescent↗
PubMed2006

Secalonic acid D; A cytotoxic constituent from marine lichen-derived fungus Gliocladium sp. T31.

Secalonic acid D (SAD) was isolated as the major secondary metabolite of the marine lichen-derived fungus Gliocladium sp. T31. Its structure was established on the basic of physico-chemical and spectroscopic data. This is the first report on the isolation of SAD from this fungus, as well as its inhibitory effect on K562 cell cycle and its cytotoxicity against several tumor cell lines in vitro.

Antineoplastic Agents↗
PubMed2006

Tissue-engineered graft constructed by self-derived cells and heterogeneous acellular matrix.

BACKGROUND: Endothelial and smooth muscle cells were used as seeding cells and heterogeneous acellularized matrix was used as scaffold to construct the tissue-engineered graft. METHODS: A 2 weeks piglet was selected as a donor of seeding cells. Two-centimetre length of common carotid artery was dissected. Endothelial cells and smooth muscle cells were harvested by trypsin and collagenase digestion respectively. The isolated cells were cultured and expanded using routine cell culture technique. An adult sheep was used as a donor of acellularized matrix. The thoracic aorta was harvested and processed by a multi-step decellularizing technique to remove the original cells and preserve the elastic and collagen fibers. The cultured smooth muscle cells and endothelial cells were then seeded to the acellularized matrix and incubated in vitro for another 2 weeks. The cell seeded graft was then transplanted to the cell-donated piglet to substitute part of the native pulmonary artery. RESULTS: The cultured cells from piglet were characterized as endothelial cells by the presence of specific antigens vWF and CD31, and smooth muscle cells by the presence of specific antigen alpha-actin on the cell surface respectively with immunohistochemical technique. After decellularizing processing for the thoracic aorta from sheep, all the cellular components were extracted and elastic and collagen fibers kept their original morphology and structure. The maximal load of acellular matrix was decreased and 20% lower than that of untreated thoracic aorta, but the maximal tensions between them were not different statistically and they had similar load-tension curves. Three months after transplantation, the animal was sacrificed and the graft was removed for observation. The results showed that the inner surfaces of the graft were smooth, without thrombosis and calcification. Under microscopy, a great number of growing cells could be seen and elastic and collagen fibers were abundant. CONCLUSION: Cultured self-derived endothelial and smooth muscle cells could be used as seeding cells and heterogeneous acellularized matrix could be used as scaffold in constructing tissue-engineered graft.

Animals↗
PubMed2006

[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.

Animals↗
PubMed2006

[Immune adjuvant effect of TB.HSP70 to its accompanying cytotoxic T lymphocytes epitope elicits HBV specific immune response].

OBJECTIVE: To investigate whether Mycobacterium tuberculosis heat shock protein 70 (TB.HSP70) can be used as an adjuvant carrier to stimulate immune response to an accompanying cytotoxic T lymphocytes (CTL) epitope peptide from hepatitis B virus (HBV) core antigen. METHODS: In vitro, peripheral blood mononuclear cells (PBMCs) from chronic hepatitis B volunteers were stimulated with TB.HSP70-CTL fusion protein and TB.HSP70/CTL complex, and then HBV specific CTL activity was assessed. In vivo, the CD4+ T, CD8+ T and natural killer cells (NKs) in the peripheral blood and in spleens of the immunized mice were measured by flow cytometry and the protective HBV specific immune responses of the mice were also evaluated. RESULTS: The results revealed that both of them could induce HBV specific CTL response in human PBMCs and in the immunized mice. In the mice they activated CD4+ T, CD8+ T and NKs. Furthermore, the immunocompetence of the TB.HSP70-CTL fusion protein was stronger than that of TB.HSP70/CTL complex. The HBV specific killing rate was 28.9%, the CD8+ T cell population was 43.9% and the NKs was 13.6% in splenocytes of immunized mice with TB.HSP70-CTL fusion protein. The CTL peptide alone was capable of generating weak CTL lysis. The TB.HSP70 showed almost no target cell killing. CONCLUSION: The results demonstrate that TB.HSP70 may be used as a new adjuvant carrier to improve the immunogenicity of short CTL epitope and produce effective CTL response.

Adjuvants, Immunologic↗
PubMed2006

[Effect of tumor antigen specific CTL induced by dendritic cells on a model of human hepatocellular carcinoma in nude mice (LCI-D20)].

OBJECTIVES: To investigate the cure effect of tumor antigen specific CTL on a model of human hepatocellular carcinoma in nude mice LCI-D20. METHODS: Dendritic cells (DCs) were induced from peripheral blood mononuclear cells of healthy people in vitro by using recombinant human granulocyte-macrophage colony stimulating factor (rhGM-CSF) and interleukin-4 (rhIL-4) and were pulsed with tumor antigen from hepatocellular carcinoma cell line MHCC97H. Then tumor antigen specific cytotoxic T lymphocytes (CTLs) were induced. By intraperitoneal injection of tumour antigen specific CTLs into the LCI-D20, the preventive and therapeutic effects of these CTLs to HCC in the LCI-D20 model were assessed. Cytokine-induced killer (CIK) cells and phosphate buffer solution were used as controls at the same time. RESULTS: The weights of tumors in the tumor antigen specific CTL group, in the CIK cell group and in the blank group were (1.11+/-0.63), (1.12+/-0.36) and (2.68+/-0.53) grams respectively (t = 5.18, t = 6.06, P < 0.01). The amount of blood alpha fetal protein in the tumor antigen specific CTL and CIK groups were (52.1+/-9.7) microg/L and (48.6+/-5.2) microg/L, and was (82.2+/-7.2) microg/L in the blank group (t = 17.26, t = 22.07, P < 0.01 respectively). The metastasis rates in livers were 16.7%, 16.7% and 58.3% in the tumor antigen specific CTL, CIK cell and blank control groups respectively (chi2= 4.44, P < 0.01). The survival time of the mice in the tumor antigen specific CTL group was (79.0+/-5.02) days, (73.3+/-7.0) days in the CIK group, and (52.3+/-5.2) days in the blank group (t = 14.56, t = 17.54, P < 0.01). CONCLUSION: Tumor antigen specific CTLs may prevent metastasis in the LCI-D20 model and prolong the survival time.

Animals↗
PubMed2006

[Immunotherapy with a chimeric AFP and HSP70 gene DNA vaccine targeting on a murine hepatocellular carcinoma].

OBJECTIVES: To investigate immune responses and the anti-tumor effect of a constructed Chimeric AFP-Mt.HSP70 DNA vaccine in mice. METHODS: Chimeric AFP-Mt.HSP70 was constructed by molecular clone techniques. Spleen cells derived from mice immunized twice were induced to secrete IFN gamma and were assayed using ELISA. The activity of the cytotoxic lymphocytes (CTL) derived from spleen cells was assayed using lactate dehydrogenase (LDH). 4 x 10(6) Hepa1-6 cells/200 microl were injected subcutaneously into the right axilla of each mouse bearing the tumor. The anti-tumor effect of the recombinant DNA vaccine was evaluated by measuring tumor sizes of the mice. RESULTS: AFP-specific CTL reaction was induced by our chimeric DNA vaccine and Mt.HSP70 enhanced this effect (P < 0.05). The CTL activity was about 32% at E/T=50:1. The IFN gamma secreted by spleen cells of mice immunized with chimeric plasmids was about 200 pg/ml. It was higher than those in the other groups; Tumor sizes of mice immunized with fused plasmids were smaller than those in the other groups. Survival times of mice immunized with the fused plasmids were prolonged. CONCLUSION: Chimeric DNA vaccine can induce AFP-specific CTL reaction and has an anti-tumor effect on transplanted tumors in our murine experiment.

Animals↗
PubMed2006

[Study on risk factors of sporadic hepatitis E virus cases in some districts of Shanghai].

OBJECTIVE: To study the risk factors of acute sporadic hepatitis E virus (HEV) cases and to analyze its partial sequence in some districts of Shanghai. METHODS: 30 blood samples were collected from the acute sporadic HEV cases in 2003-2004 and the RT-nPCR method was applied to obtain the sequence of HEV in these cases. Meanwhile, a 1:2 case-control study was used to identify risk factors in the process of sporadic HEV infection in these regions of Shanghai. RESULTS: Data from the sequential analysis showed that HEV of the sporadic cases belonged to HEV genotype IV. Finding from the case-control study implicated that the housing condition, outside eating history, especially seafoods (OR = 7.048) played an important role in the infection of HEV. Results from multiple logistic regression showed that eating raw seafoods appeared to be one of the risk factors of HEV infection. CONCLUSION: HEV sequences isolated from the sporadic cases of HEV in some districts of Shanghai belonged to HEV genotype IV. Foods, especially seafood, were the risk factors in the infection of HEV.

Acute Disease↗
PubMed2006

[Screening and their anti-tumor activity of antisense oligodeoxynucleotides targeting KDR mRNA in breast cancer MCF-7 cells].

OBJECTIVE: To screen the antisense oligodeoxynucleotides (asONs) which could hybridize with KDR (kinase insert domain-containing receptor) mRNA in an effective and specific way and to explore their anti-tumor effects on breast cancer MCF-7 cell line in vitro. METHODS: The asONs were firstly selected using oligodeoxynucleotides library hybridization or computer prediction, then their hybridization ability with KDR mRNA was further tested with oligonucleotide microarray. The asONs with strong hybridization intensity were selected. Their inhibitory effects on MCF-7 cells proliferation and KDR expression were assayed by MTT, RT-PCR and Western blotting assay, respectively. RESULTS: In 13 asONs selected with oligodeoxynucleotides library hybridization, 8 (8/13, 61.5%) showed strong hybridization signals, while such was only 1 in 17 asONs designed by computer prediction. 9 asONs with strong hybridization intensity were selected and synthesized with phosphorothioated modification. All these asONs inhibited the MCF-7 cells proliferation in a dose-dependent manner, in which asON4 and asON7 screened by oligodeoxynucleotides library in combination with oligonucleotide microarray were the most effective, with inhibitory rates of 51.6% and 62.2% at 0.8 micromol/L, respectively. The KDR expression at mRNA and protein levels was reduced by both the two asONs, in a dose-dependent manner. CONCLUSION: asONs screened by oligodeoxynucleotides library hybridization are well consistent with that chosen with oligonucleotide microarray. The combination of oligodeoxynucleotides library with oligonucleotide microarray is an effective approach of asONs screening. The asONs targeting KDR mRNA showed prominent anti-tumor activity on breast cancer MCF-7 cells.

Breast Neoplasms↗