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Biomedical subjects

Hong Tang

Publications and source records attributed to Hong Tang.

At least 19 recordsLinked to original sources

Label-Free Urinary Proteomics Uncovers Immune-Related Non-Invasive Biomarkers for Primary Biliary Cholangitis.

Diagnosis of primary biliary cholangitis (PBC) currently depends on invasive liver biopsy or serum markers with inadequate diagnostic performance. This study aimed to identify non-invasive urinary protein biomarkers for PBC detection. Urine specimens from biopsy-verified PBC patients and healthy controls were processed through ultracentrifugation-based protein extraction, enzymatic digestion, and HPLC-ESI-IT/MS proteomic profiling; protein quantification was completed using Spectronaut v14.8. We identified 194 differentially expressed urinary proteins (109 upregulated, 85 downregulated) and screened 10 immune-related candidates through GO and KEGG enrichment. Pearson correlation further filtered three core proteins, osteopontin (SPP1/OPN), RAMP3 and S100A8, that correlated significantly with key PBC biochemical indices (ALP, GGT, AST, ALT, IgM, p < 0.05). Elevated urinary concentrations of OPN, RAMP3 and S100A8 were validated by ELISA in an independent cohort containing 30 PBC patients and 20 healthy volunteers. In summary, urinary OPN, RAMP3 and S100A8 are markedly increased in PBC patients and hold promise as non-invasive diagnostic biomarkers for PBC; however, their diagnostic specificity against other cholestatic and autoimmune liver diseases remains to be evaluated, and further confirmation in larger multicenter cohorts with disease control groups is warranted.

Humans↗

Advances in Helicobacter pylori lipopolysaccharide structure and function.

Helicobacter pylori is a widespread pathogen responsible for chronic gastritis, peptic ulcers, and an elevated risk of gastric cancer. Lipopolysaccharide (LPS), localized exclusively in the outer leaflet of the outer membrane, is essential for maintaining bacterial integrity. Recent advances have deepened our understanding of H. pylori LPS structure, particularly lipid A modifications and the redefinition of the core oligosaccharide and O-antigen regions. The complete set of enzymes involved in LPS biosynthesis has been identified in the reference strain G27, and comparative genomics has revealed a notable regional difference (the absence of the heptan domain in East Asian strains). Here, we summarize recent insights into the structure and function of H. pylori LPS, emphasizing its role in bacterial persistence and its promise as a target for LPS-based glycoconjugate vaccine development.

Helicobacter pylori↗

Internalization of CD40 regulates its signal transduction in vascular endothelial cells.

The CD40 ligand (CD40L)-CD40 dyad can ignite proinflammatory and procoagulatory activities of the vascular endothelium in the pathogenesis and progression of atherosclerosis. Besides being expressed on the activated CD4(+) T cell surface (mCD40L), the majority of circulating CD40L reservoir (sCD40L) in plasma is released from stimulated platelets. It remains debatable which form of CD40L triggers endothelial inflammation. Here, we demonstrate that the agonistic antibody of CD40 (G28.5), which mimics the action of sCD40L, induces rapid endocytosis of CD40 independent of TRAF2/3/6 binding while CD40L expressed on the surface of HEK293A cells captures CD40 at the cell conjunction. Forced internalization of CD40 by constitutively active mutant of Rab5 preemptively activates NF-kappaB pathway, suggesting that CD40 was able to form an intracellular signal complex in the early endosomes. Internalized CD40 exhibits different patterns of TRAF2/3/6 recruitment and Akt phosphorylation from the membrane anchored CD40 complex. Finally, mCD40L but not sCD40L induces the upregulation of proinflammatory cytokines and cell adhesion factors in the primary human vascular endothelial cells in vitro, although both forms of CD40L activate NF-kappaB pathway. These results therefore may help understand the molecular mechanism of CD40L signaling that contributes to the pathophysiology of atherosclerosis.

Animals↗

Molecular functions and biological roles of hepatitis B virus x protein.

Chronic infection of hepatitis B virus (HBV) is one of the major causes of hepatocellular carcinoma (HCC) in the world. Hepatitis B virus X protein (HBx) has been long suspected to be involved in hepatocarcinogenesis, although its oncogenic role remains controversial. HBx is a multifunctional regulator that modulates transcription, signal transduction, cell cycle progress, protein degradation pathways, apoptosis, and genetic stability by directly or indirectly interacting with host factors. This review focuses on the biological roles of HBx in HBV replication and cellular transformation in terms of the molecular functions of HBx. Using the transient HBV replication assay, ectopically expressed HBx could stimulate HBV transcription and replication with the X-defective replicon to the level of those with the wild one. The transcription coactivation is mainly contributing to the stimulatory role of HBx on HBV replication although the other functions may affect HBV replication. Effect of HBx on cellular transformation remains controversial and was never addressed with human primary or immortal cells. Using the human immortalized primary cells, HBx was found to retain the ability to overcome active oncogene RAS-induced senescence that requires full-length HBx. At least two functions of HBx, the coactivation function and the ability to overcome oncogene-induced senescence, may be cooperatively involved in HBV-related hepatocarcinogenesis.

Amino Acid Sequence↗

[Experimental study of liver fibrosis reversal effect of warming-yang compound formula ganzhifu].

OBJECTIVE: To observe the effect of Ganzhifu (GZF), a Chinese compound formula for Warming-yang on experimental hepatic fibrosis, and to explore its mechanism. METHODS: Fifty-nine Wistar rats were divided into the normal control group and the model group. After the hepatic fibrosis model was established in rats by subcutaneous injection of CCl4 and feeding 10% alcohol in the model group, the rats were randomly sub-divided into the Ganzhifu group, colchicine group and model group, they were treated with Ganzhifu, colchicine and normal saline of same volume once a day respectively for 30 days as one treatment course. The serum liver function and hepatic fibrosis indexes, liver tissue contents of hydroxyproline (Hyp), malondialdehyde (MDA) and superoxide dismutase (SOD) activity were measured at the end of the experiment. Histologic changes of liver tissue were observed and scored by the modified inflammatory activity and fibrosis semiquantative scoring system (SSS), and collagen type I , III and IV in liver tissue were stained and semiquantitive analysis conducted. RESULTS: In the Ganzhifu group, liver function and inflammatory activity and fibrosis SSS scores were markedly improved, indexes of hepatic fibrosis, liver contents of Hyp, MDA and collagen type I, III and IV were significantly decreased, and the SOD activity was increased, the changes were more significant as compared with those in the model group. The protective effect of Ganzhifu against hepatic fibrosis was the same as that of colchicine. CONCLUSION: Ganzhifu can alleviate or reverse hepatic fibrosis in experimental hepatic fibrosis, and antioxidation may be its mechanism.

Animals↗

[On the role of liver-enriched transcription factors in regulating HBV transcription and replication].

OBJECTIVE: To investigate the effects of various liver-enriched transcription factors in regulating HBV transcription and replication, and to explore their potential roles in HBV hepatotropism. METHODS: The replication-competent HBV recombinant plasmid pHBV4.1 plus different liver-enriched transcription factor (HNF1, HNF3, HNF4, HNF6, C/EBP and RXRa/PPARa) expression plasmids were co-transfected into nonhepatic cell lines (NIH3T3, HeLa, 293T, SW1353, CV-1 and COS1). The transcription levels of 3.5 kb, 2.4/2.1 kb and 0.7 kb HBV RNA were analyzed by Northern blot hybridization, and the level of HBV DNA replication intermediates was detected by Southern blot hybridization analysis. RESULTS: In the absence of co-transfected liver enriched transcription factor expression vectors, the 3.5 kb HBV RNA is not transcribed and HBV DNA replication is not detected after transfecting of NIH 3T3 cells with pHBV4.1. Expression of the liver-enriched transcription factor HNF4 or RXRalpha/PPARalpha, stimulates the transcription of 3.5 kb HBV RNA and the replication of HBV DNA. In contrast, expression of HNF1, HNF3, HNF6 and C/EBP does not stimulate the transcription of 3.5 kb HBV RNA and therefore does not activate viral replication. HNF4 and RXRalpha/PPARalpha were also shown to activate the transcription of 3.5 kb HBV RNA and viral replication in divers cell types including HeLa, 293T, SW1353, CV-1 and COS1 cells. Mutation of the proximal nucleocapsid HNF4 binding site results in a greatly decreased level of HNF4 or RXRalpha/PPARalpha dependent HBV replication. CONCLUSION: This study demonstrated that the liver-enriched transcription factors HNF4 and RXRa/PPARa can support HBV transcription and replication in nonhepatic cells, indicating that liver-specific gene transcription is one of the determinants of HBV hepatotropism.

Animals↗

[Effects of epidermal growth factor on cellular expression of estrogen and androgen receptors in mouse prostate].

OBJECTIVE: To investigate the effects of epidermal growth factor (EGF) on estrogen receptor (ER) and androgen receptor (AR) in mouse prostate cells and explore the putative role of EGF in prostatic hyperplasia. METHODS: Sixty male Kunming mice were randomly divided into two EGF groups and one control group (n=20) and subjected to subcutaneous injection of 1 and 2 microg/day EGF and distilled water, respectively, for 28 consecutive days. The cellular expression of ER and AR in the prostate of mice in different groups was evaluated by flow cytometry. RESULTS: Compared with the control group, the positivity rate of ER and its expression level were significantly increased in the mouse prostate after EGF treatment (P<0.01), and the ER expression level was significantly higher in mouse with 2 microg/day EGF treatment than in those treated with 2 microg/day EGF (P<0.01). AR positivity rate and expression level also increased significantly in comparison with the control group (P<0.05), but no significant variation was found between 1 microg/day and 2 microg/day EGF groups. CONCLUSION: EGF can increase the cellular expression of ER and AR in mice prostate and may play a role in the pathogenesis of prostatic hyperplasia.

Animals↗

[Assessment of left ventricular diastolic function by pulsed Doppler tissue imaging in patients with type 2 diabetes mellitus].

OBJECTIVE: To assess the value of pulsed Doppler tissue imaging (PW-DTI) in evaluating the left ventricular diastolic dysfunction (LVDD) in patients with type 2 diabetes mellitus (DM). METHODS: Seventy-seven type 2 diabetic patients and 43 healthy volunteers underwent PW-DTI and mitral inflow pulsed wave Doppler (MPWD). Six positions of the mitral annulus were measured by PW-DTI for early diastolic velocity (Em), end diastolic velocity (Am), Em/Am ratio. Early mitral inflow velocity (E), end mitral inflow velocity (A), left ventricular isovolumetric relaxation (IVRT) and E/A ratio were measured by MPWD. RESULTS: In the diabetic patients, Em, Em/Am and E/A ratios were significantly decreased and Am and A increased with prolonged IVRT. The two examination modalities showed a significant correlation between Em/Am and E/A. The detection rate of LVDD in the diabetic group was 94.81% by PW-DTI and 79.22% by MPWD. CONCLUSION: PW-DTI and MPWD show a significant correlation in assessment of the left ventricular filling, but the former displays better performance in sensitive and accurate diastolic function evaluation and provides early evidence for of diabetic cardiomyopathy of due to its potent ability in differentiation of false-normal presentations.

Adult↗

Mitomycin C "straight scleral tunnel incision"--trabeculectomy with a releasable suture.

OBJECTIVE: To evaluate the efficacy of "straight scleral tunnel incision" -trabeculectomy with a releasable suture supplemented with mitomycin C (MMC) on reducing intraocular pressure (IOP), complications, and corneal astigmatism in patients with primary angle-closure glaucoma (PACG). METHODS: Totally 217 acute or chronic PACG patients with occludable angle above 180 degrees and IOP above 21 mm Hg were divided into 3 groups. Patients in group A (98 cases, 128 eyes), B (71 cases, 95 eyes), and C (48 cases, 60 eyes) were treated with "straight scleral tunnel incision"-trabeculectomy with a releasable suture supplemented with MMC, releasable suture trabeculectomy with MMC, and trabeculectomy with MMC, respectively. IOP, complications, and surgically induced astigmatism (SIA) were evaluated preoperatively and up to 12 months postoperatively. RESULTS: IOP of 2 weeks after treatment was significantly lower than preoperative IOP in all the 3 groups (all P <0. 001). Success rates (IOP < or = 20 mm Hg) in group A, B, and C were 87.91%, 89.23%, and 83.72% respectively at 12 months after treatment (P = 0.256). The incidence of shallow anterior chamber and hypotony had no significant difference between group A and B, but both of them were lower than that in group C (P < 0.05). There were no significant differences in preoperative corneal astigmatism among the 3 groups. The corneal astigmatism after 2 weeks in group A (1.71 +/- 1.47D) was higher than that before operation (1.28 +/- 1.05D, P = 0.126). With 12 months gone, the astigmatism almost returned to preoperative levels. The corneal astigmatisms after 2 weeks in group B and C (1.99 +/- 1.20D and 2. 22 +/- 1.39D) were significantly higher than those before operation (1.20 +/- 0.85D and 1.18 +/- 0.93D, P = 0.002, P = 0.001), respectively. With 12 months gone, the mean astigmatisms in group B and C (1.87 +/- 0.91D and 1.90 +/- 1.16D) were still significantly higher than those before operation (P = 0.001, P = 0.003). The highest astigmatic polar values in group A, B, and C (1.00D, 1. 89D, and 1. 77D) occurred after 2 weeks, 1 month, and 1 month postoperation, respectively, which were significantly higher than those before operation (0.19 +/- 1.32D, 0.12 +/- 1.22D, and 0.17 +/- 1.25D, P < 0.01), respectively. With 12 months gone, they were 0. 03D, -0. 18D, and -0. 13D higher than those before operation, respectively. The rates of function bleb and thin-wall bleb were 71.43% and 26.37% in group A, 75.38% and 29.23% in group B, 72.09% and 25.58% in group C, respectively at 12 months after treatment There were no significant differences among the 3 groups. CONCLUSION: "Straight scleral tunnel incision" -trabeculectomy with a releasable suture supplemented with MMC can reduce complications and get satisfactory results in reducing IOP and SIA.

Aged↗

[Review of nonlinear filters for medical ultrasonic images].

Ultrasound medical imaging has been widely applied in clinic diagnoses because of its real-time, non-invasiveness and convenience. However, it suffers from severe speckle noises. Until now, a lot of filtering algorithms have been proposed, but none of them is satisfactory. In this paper, four nonlinear filter methods, based on median filter, wavelet decomposition and anisotropic diffusion, are systematically reviewed. Finally, the prospect of the nonlinear filtering method is discussed.

Algorithms↗

[A preliminary study on the extraction method of velocity pulsated signals in the velocity spectrum image of pulsed Doppler ultrasounds in vitro].

Focus on the defects of the extraction method of velocity pulsated signals in the velocity spectrum image of pulsed Doppler ultrasounds (such as the limited data, great amount of work and low reproducibility), we combine the earlier research results and the basic rules of the velocity spectrum image, and employing the visual basics plateau, to design and develop a software to extract the velocity signals from the spectrum image automatically. Compare the mean velocity and RNS between the PIV and the PDU resulting from the method, the correlations are r = 0.93 and r = 0.78 respectively. The study reveals the software increase the amount of valid data, decrease the amount of work and increase reproducibility of the signals extraction. The method may be an effective way to analyse the velocity spectrum image of PDU in clinic.

Arteries↗

Differential regulation of chromatin structure of the murine 3' IgH enhancer and IgG2b germline promoter in response to lipopolysaccharide and CD40 signaling.

Class switch recombination (CSR) of murine immunoglobulin heavy chain (IgH) is controlled by germline transcription-coupled modification of the accessibility of the highly repetitive switch regions (S) located upstream of the constant region genes. Activation of the 3' IgH enhancer (3'E) is believed to regulate CSR during B cell terminal differentiation, although the detailed molecular mechanism remains unclear. Here, we show that BAF57 and BRG1, two essential subunits of murine SWI/SNF complex, differentially associate with the DNase I hypersensitive region HS1/2 of 3'E and the IgG2b germline promoter in response to LPS activation or CD40 engagement. Both LPS and CD40 signaling cause SWI/SNF complex to dissociate from HS1/2 and associate with their responsive IgG2b germline promoter, suggesting the potential fluidity of chromatin structure and specific regulatory mode for the ATP-dependent chromatin remodeler during CSR. More interesting, increase in histone acetylation is either inverse or parallel with the action of SWI/SNF complex at HS1/2 enhancer or IgG2b germline promoter, respectively. Chromatin immunoprecipitation experiments show that alteration of histone H3 and H4 acetylation has overall similarities in response to LPS and CD40 signaling, with H3 hyperacetylated and H4 hypoacetylated at the HS1/2 enhancer and reversed modification patterns at the IgG2b germline promoter. Finally, the specificity of LPS and CD40 signaling in control of CSR could be partially coded by the specific acetylation marking of H3 and H4. Our results further strengthen the notion that chromatin remodeling plays a critical role in CSR.

Acetylation↗

Purification of infectious adenovirus in two hours by ultracentrifugation and tangential flow filtration.

Adenoviruses are excellent vectors for gene transfer and are used extensively for high-level expression of the products of transgenes in living cells. The development of simple and rapid methods for the purification of stable infectious recombinant adenoviruses (rAds) remains a challenge. We report here a method for the purification of infectious adenovirus type 5 (Ad5) that involves ultracentrifugation on a cesium chloride gradient at 604,000g for 15 min at 4 degrees C and tangential flow filtration. The entire procedure requires less than two hours and infectious Ad5 can be recovered at levels higher than 64% of the number of plaque-forming units (pfu) in the initial crude preparation of viruses. We have obtained titers of infectious purified Ad5 of 1.35x10(10) pfu/ml and a ratio of particle titer to infectious titer of seven. The method described here allows the rapid purification of rAds for studies of gene function in vivo and in vitro, as well as the rapid purification of Ad5.

Adenoviridae↗

Arsenic trioxide (As(2)O(3)) induces apoptosis through activation of Bax in hematopoietic cells.

This study explores the roles of Bax and other Bcl-2 family members play in arsenic trioxide (As(2)O(3))-induced apoptosis. We showed that As(2)O(3) treatment triggered Bax conformational change and subsequent translocation from cytosol to mitochondria to form various multimeric homo-oligomers in IM-9 cells. On the other hand, human leukemic Jurkat cells deficient in Bax showed dramatically reduced apoptosis in response to As(2)O(3). Stable overexpression of Bcl-2 in IM-9 cells (IM-9/Bcl-2) inhibited As(2)O(3)-mediated Bax activation and apoptosis, and this inhibition could be partially averted by cell-permeable Bid-Bcl-2 homology (BH)3 peptide. Meanwhile, Bax conformational change and oligomerization induced by As(2)O(3) were not inhibited by the pancaspase inhibitor z-VAD-fmk, although Bid cleavage could be completely abolished. Bax activation by As(2)O(3) seemed to require stress-induced intracellular reactive oxygen species (ROS), since the ROS scavengers (N-acetyl-L-cysteine and lipoic acid) could completely block the conformational change and translocation of Bax from cytosol to mitochondria. These data suggest that As(2)O(3) might exert the cell killing in part by inducing Bax activation through a Bcl-2-suppressible pathway in hematopoietic cells that is caspase independent and intracellular ROS regulated.

Annexin A5↗

Tissue microarray for high-throughput analysis of gene expression profiles in hepatocellular carcinoma.

AIM: To study the expression profiles of HBsAg, HBcAg, p21WAF1/CIP1 (p21), Rb genes in hepatocellular carcinoma (HCC) and to investigate their roles in the hepatocar-cinogenesis. METHODS: HCC tissue microarray containing 120-min tissues of 40 HCC cases was constructed. HBsAg, HBcAg, p21 and Rb proteins were immunohistochemically stained by streptavidin-peroxidase conjugated method (S-P). The expression loss of these genes in cancerous, para-cancerous tissues and adjacent normal liver tissues of 40 HCCs were comparatively examined. RESULTS: The positive rate of HBsAg expression in cancerous tissues of 40 HCCs was 7.5%, which was lower than that in para-cancerous and adjacent normal liver tissues (chi2 =12.774, P < 0.01; chi2 = 18.442, P < 0.01). The positive rate of HBcAg expression in cancerous tissues of 40 HCCs was 20.0%, which was also lower than that in para-cancerous and adjacent normal liver tissues (chi2 = 9.482, P < 0.01; chi2 = 14.645, P < 0.01). p21 protein deletion rate in cancerous tissues of 40 HCCs was 27.5%, which was higher than that in para-cancerous and adjacent normal liver tissues (chi2 = 7.439, P < 0.01; chi2 = 11.174, P < 0.01). p21 protein deletion correlated remarkably with the pathological grade of HCC (chi2 = 0.072, P < 0.05). Rb protein deletion rate in cancerous tissues of 40 HCCs was 42.5%, which was also higher than that in para-cancerous and adjacent normal liver tissues (chi2 = 10.551, P < 0.01; chi2 = 18.353, P < 0.01). Rb protein deletion rate did not correlate remarkably with tumor size or pathological grade of HCC (chi2 = 0.014, P > 0.05; chi2 = 0.017, P > 0.05). CONCLUSION: Expression deletion of HBsAg, HBcAg, p21 and Rb proteins in HCCs may play important roles in the carcinogenesis of HCC. Tissue microarray is an effective high-throughput technique platform for cancer research.

Carcinoma, Hepatocellular↗

Specific cleavage of Mcl-1 by caspase-3 in tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced apoptosis in Jurkat leukemia T cells.

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) induces programmed cell death through the caspase activation cascade and translocation of cleaved Bid (tBid) by the apical caspase-8 to mitochondria to induce oligomerization of multidomain Bax and Bak. However, the roles of prosurvival Bcl-2 family proteins in TRAIL apoptosis remain elusive. Here we showed that, besides the specific cleavage and activation of Bid by caspase-8 and caspase-3, TRAIL-induced apoptosis in Jurkat T cells required the specific cleavage of Mcl-1 at Asp-127 and Asp-157 by caspase-3, while other prototypic antiapoptotic factors such as Bcl-2 or Bcl-X(L) seemed not to be affected. Mutation at Asp-127 and Asp-157 of Mcl-1 led to cellular resistance to TRAIL-induced apoptosis. In sharp contrast to cycloheximide-induced Mcl-1 dilapidation, TRAIL did not activate proteasomal degradation of Mcl-1 in Jurkat cells. We further established for the first time that the C-terminal domain of Mcl-1 became proapoptotic as a result of caspase-3 cleavage, and its physical interaction and cooperation with tBid, Bak, and voltage-dependent anion-selective channel 1 promoted mitochondrial apoptosis. These results suggested that removal of N-terminal domains of Bid by caspase-8 and Mcl-1 by caspase-3 enabled the maximal mitochondrial perturbation that potentiated TRAIL-induced apoptosis.

Amino Acid Sequence↗

Theoretical studies on the optical spectra and EPR parameters for trigonal Yb3+ center in CsCdBr3 crystal.

In this paper, the crystal-field energy levels, the EPR g factors g//, g(perpendicular) of Yb3+ and hyperfine structure constants A//, A(perpendicular) of 171Yb3+ and 173Yb3+ isotopes in CsCdBr3 crystal are calculated from the crystal-field theory. The calculated results (seven energy levels and six EPR parameters) are in reasonable agreement with the observed values. In the calculation, we find that Yb3+ ion does not occupy the exact Cd2+ site, but is shifted from the center of bromine octahedron by a distance (Delta)Z approximately 0.184 angstroms along C3 axis. The results are discussed.

Bromine↗