Biomedical subjects

Ning Xu

Publications and source records attributed to Ning Xu.

At least 19 recordsLinked to original sources

PubMed2026

Could the preoperative urethral curve be used to predict immediate urinary continence following Retzius-sparing robot-assisted radical prostatectomy? A retrospective multi-center study.

PURPOSE: Immediate urinary continence (UC) recovery following Retzius-sparing robot-assisted radical prostatectomy (RS-RARP) remains highly variable, highlighting the need for reliable preoperative prediction. We aimed to develop and validate models to identify patients likely to achieve immediate UC recovery following RS-RARP. MATERIALS AND METHODS: A total of 580 prostate cancer patients who underwent RS-RARP from four medical centers were assigned to a training set (n=348), an internal validation set (n=103) and an external validation set (n=129). Independent predictors were identified through univariate analysis and LASSO regression. A nomogram was constructed using multivariate logistic regression. Its performance was evaluated with receiver operating characteristic (ROC) curve, calibration curves, and decision curve analysis. RESULTS: Immediate UC recovery was observed in 84.5% (294/348) of patients in the training cohort, 80.6% (83/103) in the internal validation cohort, and 81.4% (105/129) in the external validation cohort, respectively. Multivariate analysis identified membranous urethral length (MUL) (OR=1.23, P=0.029) and urethral curvature (OR=2.84, P<0.001) as independent predictors, while prostate volume (PV) (OR=0.84, P <0.001) as a protective factor. The nomogram integrating MUL, PV, and urethral curvature demonstrated superior predictive accuracy, with an AUC of 0.87 (95% CI, 0.83-0.91) in the training cohort. The bootstrap-corrected calibration slope was 0.96, and the Brier score was 0.08. Calibration curves and decision curve analysis confirmed the predictive accuracy and clinical utility of the nomogram. CONCLUSIONS: Our study introduces a novel quantitative method for assessing urethral curvature. The mpMRI-based model, integrating urethral curvature and prostate spatial configuration, offers enhanced predictive accuracy for postoperative immediate UC recovery.

Humans↗

PubMed2025

A complete and near-perfect rhesus macaque reference genome: lessons from subtelomeric repeats and sequencing bias.

A truly complete, telomere-to-telomere (T2T), and error-free reference genome remains a foundational resource-and long-standing goal-for unbiased comparative and functional genomics. While recent T2T assemblies of humans and other primates have made substantial progress, most still contain thousands of base-level errors, particularly within highly repetitive regions. Here, we present T2T-MMU8v2.0, a near-perfect T2T assembly of the rhesus macaque (Macaca mulatta), representing the highest base-level accuracy reported in a primate genome to date. By employing an optimized ONT-only assembly strategy, we identify subtelomeric satellite-rich regions as the principal bottleneck to improving assembly quality, owing to technological biases in long-read platforms and limitations in current hybrid assembly frameworks. We discover 268 previously unannotated repeat families and resolve ~8 Mbp of SATR satellite arrays, with over 99-fold enrichment in historically misassembled subtelomeric regions. These satellites form four distinct genomic architectures, each with unique SATR satellite composition, segmental duplication organization, and epigenetic signatures, distinct from the subtelomeric architectures observed in hominid genomes. Notably, in contrast to the largely gene-poor subtelomeric regions in African hominids, the SATR architectures in macaques harbor 58 actively transcribed genes, supported by open chromatin and expression data, suggesting gene innovation within these repetitive regions. Functionally, T2T-MMU8v2.0 improves read mappability and accuracy across sequencing platforms, and results in a 19% improvement of transcription start site enrichment scores and 5,821 additional chromatin accessibility peaks on average, thereby enhancing variant detection, regulatory annotation, and transcriptomic resolution in population genetics or single-nucleus studies. Together, this work establishes a new benchmark for genomics, offers a roadmap for resolving complex repetitive regions, and reveals previously unrecognized features of subtelomeric genome structure and evolution.

Journal Article↗

PubMed2007

KAL1 mutations are not a common cause of idiopathic hypogonadotrophic hypogonadism in humans.

Hypogonadotrophic hypogonadism results in the absence of puberty and if left untreated leads to infertility. Mutations in KAL1 are known to account for some of the cases of Kallmann syndrome. The aim of this study was to determine the prevalence of KAL1 mutations in a large number of patients with idiopathic hypogonadotrophic hypogonadism (IHH). One hundred and thirty eight patients (109 males and 29 females) with IHH were studied for mutations in KAL1. DNA from these patients was subjected to denaturing gradient gel electrophoresis or single strand conformation polymorphism to identify mutations. Sequencing was performed to confirm mutations detected. Four mutations were found in 109 males (3.7%). All four mutations were in anosmic/hyposmic men making the prevalence 4/63 (6.3%) in this group of patients. No mutations were found in the 29 female patients. KAL1 mutations are an uncommon cause of Kallmann syndrome.

Adult↗

PubMed2007

A mutation in the fibroblast growth factor receptor 1 gene causes fully penetrant normosmic isolated hypogonadotropic hypogonadism.

CONTEXT: Kallmann syndrome (KS) consists of idiopathic hypogonadotropic hypogonadism (IHH) and anosmia/hyposmia. Currently, the fibroblast growth factor receptor 1 (FGFR1) gene is the only known autosomal dominant cause of KS, which is also associated with synkinesia, midfacial defects, and dental agenesis. OBJECTIVE: Mutations in FGFR1 typically demonstrate reduced penetrance, variable expressivity, and until recently have been exclusively identified in families with anosmia. The purpose of this study was to determine whether FGFR1 mutations were present in a unique family with autosomal dominant, fully penetrant, normosmic IHH. DESIGN: The study is a review of detailed clinical findings, dynamic endocrine studies, and performance of a molecular analysis of the FGFR1 gene. SETTING: The study was carried out in an academic medical center. PATIENTS: All four affected individuals have complete IHH with full penetrance but no anosmia/hyposmia, and they have none of the FGFR1-associated anomalies. In addition, no other family member has anosmia. Inverventions: Interventions included detailed phenotype characterization including history, physical exam, smell testing, dynamic pituitary testing, brain imaging, and molecular analysis. MAIN OUTCOME MEASURES: Outcome was measured by the determination of the severity of IHH, olfactory function, and sequence of the FGFR1 gene. RESULTS: The same heterozygous nonsense mutation, Arg622X, was present in all four affected members, but not in three unaffected members or 100 controls. The mutation is predicted to encode a truncated protein or result in nonsense-mediated decay. CONCLUSIONS: Our findings indicate that mutations in the FGFR1 gene can cause normosmic, fully penetrant, complete IHH with little or no variable expressivity, and without the other FGFR1-associated anomalies typically found in KS.

Adolescent↗

PubMed2006

The transport of alpha(1A)-adrenergic receptor with 33-nm step size in live cells.

We used the technique of single particle tracking (SPT) with high tempo-spatial resolution to efficiently explore the route and mechanism for the transport of alpha(1A)-adrenergic receptor (alpha(1A)-AR) in real time in living cells. We found that the initial transport of alpha(1A)-AR in cells depended on actin filaments with the velocity of 0.2 microm/s and exhibited discrete 33-nm steps. It was noted that the step size, the rate constant, and the velocities were in accordance with the character of single myosin in vitro, implying that while transporting each endosome myosins did not work in the "tug-of-war" mode and that they did not adopt the strategy to boost up transporting speed by working coordinately. These results provided insight into the mechanism of GPCR transport in vivo.

Actins↗

PubMed2006

ACTH reduces the rise in ApoB-48 levels after fat intake.

It has been repeatedly demonstrated that ACTH administration lowers plasma lipid concentrations in man. The present study was designed to test the hypothesis, based on observations of decreased apolipoprotein B (ApoB) synthesis and secretion in vitro, that ACTH administration inhibits the postprandial output of ApoB in man. Therefore, we studied the response to a fat-rich meal supplemented with Vitamin A in eight healthy volunteers, who underwent this test without premedication, after 4 days administration of ACTH, and after 4 days administration of a glucocorticoid (betamethasone). As expected, fasting plasma levels of low-density lipoproteins (LDL)-cholesterol (-25%) and ApoB (-17%) decreased after ACTH, but not after betamethasone administration. Also, the elevation of plasma ApoB-48 in response to fat intake (to twice the basal levels) was markedly reduced after ACTH administration. However, the postprandial rise in plasma triglycerides and retinyl palmitate was unimpaired, suggesting that ACTH administration induced the secretion of fewer but larger chylomicrons. The effect of betamethasone on the postprandial response was similar but less pronounced. This study confirms earlier reports on the lipid-lowering effects of ACTH and supports our theory, based on in vitro studies, that the lipid-lowering effects of ACTH administration in man involves an inhibition of ApoB production.

Adrenocorticotropic Hormone↗

PubMed2006

Role of endothelin-1 and nitric oxide bioavailability in transplant-related vascular injury: comparative effects of rapamycin and cyclosporine.

BACKGROUND: Cyclosporine (CyA) is associated with many side effects, including endothelial dysfunction and transplant vasculopathy (TxV). We previously demonstrated that CyA results in impairment of nitric oxide bioavailability and enhanced sensitivity to endothelin-1 (ET-1). In this study, we evaluated rapamycin (SRL) for its effects on the endothelium. METHODS AND RESULTS: Lewis rats (n = 8) were injected with SRL (1.5 mg/kg), CyA (5 mg/Kg), or saline (Con) intraperitoneally daily for 2-weeks. Thoracic aortic segments were assessed for endothelial-dependent (Edep) and independent (Eind) relaxation after exposure to acetylcholine and sodium nitroprusside by deriving the percent maximum relaxation (Emax). ET-1 plasma levels were also measured. Thoracic aortic expression of endothelial nitric oxide synthase (eNOS), ET(A) and ET(B) receptors (Rc), were determined. Oxidative injury was assessed by changes in 8-isoprostane levels. CyA exposure resulted in lower Edep vasorelaxation compared with control and SRL (Emax: SRL, 58+/-4%; CyA, 24+/-7%; Con, 52+/-8%; P=0.001). No differences in Eind vasorelaxation were seen. CyA exposure also increased sensitivity to ET-1 (% maximum contraction [Cmax]: Con, 211+/-8%; SRL, 230+/-5%; CyA, 259+/-3%; P=0.04). Only SRL treatment reduced ET-1 plasma levels. CyA reduced eNOS expression by 30% and increased ETA Rc expression by 34% compared with both Con and SRL (P=0.02). CyA resulted in higher 8-isoprostane levels (CyA, 50+/-2%; SRL, 3+/-3%; Con, 2+/-5%; P=0.02). CONCLUSIONS: CyA results in vascular dysfunction characterized by impairment of Edep vasorelaxation and enhanced sensitivity to vasospasm. SRL did not impair Edep vasorelaxation or increase sensitivity to vasospasm while lowering ET-1 levels and preserving eNOS protein expression. We conclude that SRL is less deleterious to the vasculature than CyA and may prevent TxV by these mechanisms.

Acetylcholine↗

PubMed2006

Elevated endothelin-1 levels impair nitric oxide homeostasis through a PKC-dependent pathway.

BACKGROUND: Endothelin-1 (ET-1) plays an important role in the maintenance of vascular tone and pathological states such as ischemia/reperfusion (I/R) injury, coronary vasospasm, and cardiac allograft vasculopathy. We assessed the effects of elevated ET-1 levels as seen after I/R to determine if ET-1 modulates nitric oxide (NO) production via the translocation of specific protein kinase C (PKC) isoforms. METHODS AND RESULTS: Human saphenous vein endothelial cells (HSVECs) (n=8) were incubated with ET-1 or phosphate-buffered saline (PBS) for 24 hours. NO production was determined in the supernatant by measuring nitrate/nitrite levels. Protein expression of endothelial nitric oxide synthase (eNOS), inducible NOS (iNOS), caveolin-1 and PKC were determined. Lastly, PKC translocation and activity were assessed after exposure to the drug of interest. HSVECs exposed to ET-1 displayed decreased NO production. PKC inhibition reduced NO production, whereas PKC activation increased production. NO production was maintained when HSVECs exposed to ET-1 were treated with the PKC agonist, PMA. eNOS protein expression was reduced after ET-1 treatment. PKC inhibition also downregulated eNOS protein expression, whereas PMA upregulated expression. ET-1 exposure led to a significant increase in PKCdelta and PKCalpha translocation compared with control, whereas translocation of PKClambda was inhibited. ET-1 exposure significantly reduced overall PKC activity compared with control. CONCLUSIONS: Our study demonstrates that high levels of ET-1 impair endothelial NO production via an isoform-specific PKC-mediated inhibition of eNOS expression. ET-1 antagonism with bosentan stimulates translocation of PKClambda and leads to increased PKC activity and NO production. ET-1 antagonism may provide a novel therapeutic strategy to improve vascular homeostasis.

Alkaloids↗

PubMed2006

Measurements of the yield stress in frictionless granular systems.

We perform extensive molecular dynamics simulations of two-dimensional frictionless granular materials to determine whether these systems can be characterized by a single static yield shear stress. We consider boundary-driven planar shear at constant volume and either constant shear force or constant shear velocity. Under steady flow conditions, these two ensembles give similar results for the average shear stress versus shear velocity. However, near jamming it is possible that the shear stress required to initiate shear flow can differ substantially from the shear stress required to maintain flow. We perform several measurements of the shear stress near the initiation and cessation of flow. At fixed shear velocity, we measure the average shear stress Sigma(yv) in the limit of zero shear velocity. At fixed shear force, we measure the minimum shear stress Sigma(yf) required to maintain steady flow at long times. We find that in finite-size systems Sigma(yf) > Sigma(yv), which implies that there is a jump discontinuity in the shear velocity from zero to a finite value when these systems begin flowing at constant shear force. However, our simulations suggest that the difference Sigma(yf) - Sigma(yv), and thus the discontinuity in the shear velocity, tend to zero in the infinite-system-size limit. Thus, our results imply that in the large-system limit, frictionless granular systems can be characterized by a single static yield shear stress. We also monitor the short-time response of these systems to applied shear and show that the packing fraction of the system and shape of the velocity profile can strongly influence whether or not the shear stress at short times overshoots the long-time average value.

Journal Article↗

PubMed2006

Mammalian tolloid alters subcellular localization, internalization, and signaling of alpha(1a)-adrenergic receptors.

In the present study, we identified the CUB5 domain of mammalian Tolloid (mTLD) as a novel protein binding to alpha(1A)-adrenergic receptor (AR) using the yeast two-hybrid system. Whereas CUB5 did not couple to either alpha(1B)-AR or alpha(1D)-AR. It was determined that amino acids 322 to 359 of alpha(1A)-AR were the major binding region for CUB5. The direct interaction between alpha(1A)-AR cytoplasmic tail and CUB5 was discovered by glutathione S-transferase pull-down assay. We confirmed the interaction of mTLD with alpha(1A)-AR in human embryonic kidney (HEK) 293 cells by immunoprecipitation, immunofluorescence, and fluorescence resonance energy transfer. Although mTLD did not affect the density and affinity of receptors in crudely prepared membranes from HEK293 cells stably expressing alpha(1A)-AR, it significantly altered the subcellular localization of the receptors. Moreover, mTLD reduced the level of cell surface alpha(1A)-ARs, delayed the initial rate of agonist-induced receptor internalization, and facilitated agonist-induced calcium transient. We have demonstrated that mTLD interacts with alpha(1A)-AR directly, alters the subcellular localization of receptor, and influences agonist-induced alpha(1A)-AR internalization and calcium signaling.

Amino Acid Sequence↗

PubMed2006

Immunohistochemical localization of programmed death-1 ligand-1 (PD-L1) in gastric carcinoma and its clinical significance.

The present study examined programmed death-1 ligand-1 (PD-L1) detected by immunohistochemical labeling in 102 cases of human gastric carcinoma, 10 adenoma and 10 normal tissues. The relationship between PD-L1 immunolocalization and clinical pathological features, as well as the prognosis of gastric carcinoma, was explored. There was no PD-L1 detectable in normal gastric tissues and very weak immunolabeling in gastric adenomas, but it could be detected in 42.2% of gastric carcinoma tissues. There was no correlation between PD-L1 immunolocalization and patient age, sex, tumor location or the degree of tumor differentiation in the gastric carcinomas. However, PD-L1 immunodetection was significantly correlated to tumor size, invasion, lymph node metastasis and survival time of patients. PD-L1 immunolabeling was significantly enhanced (P<0.01) when the tumor infiltrated into the deep muscular layers, with lymph node metastasis or survival time of less than 2 years, Moreover, multivariate analysis demonstrated that PD-L1 immunodetection could be used as an independent factor to evaluate the prognosis of gastric carcinoma.

Adenoma↗

PubMed2006

Detection of carcinoembryonic antigen mRNA in peritoneal washes from gastric cancer patients and its clinical significance.

AIM: To establish a more sensitive method for detection of free cancer cells in peritoneal washes from gastric cancer patients during surgery and to evaluate its clinical significance. METHODS: The carcinoembryonic antigen (CEA) mRNA levels in peritoneal washes from 65 cases of gastric cancer were detected by real-time RT-PCR. Peritoneal lavage cytology (PLC) was applied simultaneously to detection of free cancer cells.Negative controls included peritoneal washes from 5 cases of benign gastric disease and blood samples from 5 adult healthy volunteers. RESULTS: There was no CEA mRNA in peritoneal washes from benign gastric disease patients and in blood of adult healthy volunteers. The positive percentage of free cancer cells detected by real-time RT-PCR was 47.7% and only 12.3% by PLC. The positive rate of CEA mRNA was significantly related with serosa invasion between peritoneal metastasis and stage of gastric cancer. CONCLUSION: Real-time RT-PCR is a sensitive and rapid method for the detection of free cancer cells in peritoneal washes. The presence of free cancer cells in peritoneal washes is related to the pathologic stage of gastric cancer.

Adult↗

PubMed2006

Down-regulation of apolipoprotein M expression is mediated by phosphatidylinositol 3-kinase in HepG2 cells.

Apolipoprotein M (apoM) is a novel apolipoprotein present mostly in high-density lipoprotein (HDL) in human plasma. In the present study, we demonstrate that insulin, insulin-like growth factor I (IGF-I), and IGF-I potential peptide (IGF-IPP) significantly inhibits apoM expression, in a dose- and a time-dependent manner, in the human hepatoma cell line, HepG2 cells. Insulin-induced down-regulation of apoM was blocked by AG1024 (a specific insulin receptor inhibitor) and LY294002 (a phosphatidylinositol 3-kinase (PI3K) inhibitor), which indicates that it is mediated via the activation of PI3K pathway. In contrast, PD98059 (a MAP kinase inhibitor) did not influence insulin-induced down-regulation of apoM expression, and activation of neither PPAR-alpha agonist (GW7647) nor PPAR-gamma agonist (GW1929) influences apoM expression in HepG2 cells, which indicates that regulation of apoM expression is not related to the activation of PPAR-alpha and PPAR-gamma in hepatic cells, whereas, both PPAR-alpha and PPAR-gamma agonists could inhibit apoB expression. Moreover, in the present study, we demonstrated that PPAR beta/delta agonist (GW501516) could inhibit both apoM and apoB expression in the HepG2 cells. In conclusion, this study shows that apoM expression is regulated by PI3-kinase in HepG2-cells.

Apolipoproteins↗

PubMed2006

Influence of liver cancer on lipid and lipoprotein metabolism.

Liver plays a key role in the metabolism of plasma apolipoproteins, endogenous lipids and lipoproteins. Hepatocellular carcinoma (HCC) is one of the most common fatal malignant tumors in China and in other Southeast Asian countries. This has been attributed to the high incidence of hepatitis B infection. Hepatitis B proteins, such as the hepatitis B X protein (HBx) that is large hepatitis B surface protein could regulate transcription of many candidate genes for liver carcinogenesis. It has known that patients who suffered from acute hepatitis B could have lipid disorders such as decreased plasma level of high-density lipoproteins (HDL). Furthermore, aberrations of lipid metabolism are often seen in the chronic hepatitis B infection. Plasma lipid profiles could be changed under HCC. In majority of the reports in HCC, plasma levels of triglycerides (TG), cholesterol, free fatty acids (FFA), HDL, low-density lipoproteins (LDL), lipoprotein (a) (Lp(a)), apolipoprotein AI (apoAI) and apoB were slight to significantly decreased, however, in some cases plasma levels of TG and Lp(a) might be increased. It has been suggested that analysis of plasma levels of lipids, lipoproteins and apolipoproteins in the patients suffered from HCC reflects on the hepatic cellular impairment status. Studies revealed that alterations seen in the plasma levels of lipids, lipoproteins and apolipoproteins reflecting patients' pathologic conditions. Decreased serum levels of cholesterol and apoAI may indicate a poor prognosis. Human leukaemic cells and certain tumor tissues have a higher receptor-mediated uptake of HDL and LDL than the corresponding normal cells or tissues. LDL and HDL have therefore been proposed as a carrier for the water-insoluble anti-cancer agents.

Antineoplastic Agents↗

PubMed2006

Suppression of apolipoprotein M expression and secretion in alloxan-diabetic mouse: Partial reversal by insulin.

We previously reported that apolipoprotein M (apoM) expression is reduced in ob/ob mice. Whether such a reduction is specific for this model or is a more general phenomenon in diabetes models is not known. In the present study, we therefore investigated apoM expression and secretion in NMRI mice rendered diabetes through administration of alloxan (120 mg/kg). Plasma glucose levels were markedly increased and plasma insulin levels markedly reduced at 3 days after alloxan. At the same time, that plasma apoM concentrations were decreased by 70%, apoM mRNA levels in liver was decreased by 40%, and apoM mRNA in kidney was decreased by 20% in alloxan-treated mice compared to saline-injected controls. Furthermore we found also that daily sc administration of insulin (5 IU/kg per day) increased plasma apoM levels, and apoM mRNA levels in liver and kidney. We therefore conclude that apoM is reduced in this diabetes model and that exogenous insulin administrations partially reverses the abnormal apoM expression. Based on these results, we suggest that insulin regulates apoM synthesis in vivo and, therefore, that the reduction of apoM expression is a general phenomenon in diabetes models.

Adaptation, Physiological↗

PubMed2006

Hyperbaric oxygen preconditioning induces tolerance against spinal cord ischemia by upregulation of antioxidant enzymes in rabbits.

The present study examined the hypothesis that spinal cord ischemic tolerance induced by hyperbaric oxygen (HBO) preconditioning is triggered by an initial oxidative stress and is associated with an increase of antioxidant enzyme activities as one effector of the neuroprotection. New Zealand White rabbits were subjected to HBO preconditioning, hyperbaric air (HBA) preconditioning, or sham pretreatment once daily for five consecutive days before spinal cord ischemia. Activities of catalase (CAT) and superoxide dismutase were increased in spinal cord tissue in the HBO group 24 h after the last pretreatment and reached a higher level after spinal cord ischemia for 20 mins followed by reperfusion for 24 or 48 h, in comparison with those in control and HBA groups. The spinal cord ischemic tolerance induced by HBO preconditioning was attenuated when a CAT inhibitor, 3-amino-1,2,4-triazole,1 g/kg, was administered intraperitoneally 1 h before ischemia. In addition, administration of a free radical scavenger, dimethylthiourea, 500 mg/kg, intravenous, 1 h before each day's preconditioning, reversed the increase of the activities of both enzymes in spinal cord tissue. The results indicate that an initial oxidative stress, as a trigger to upregulate the antioxidant enzyme activities, plays an important role in the formation of the tolerance against spinal cord ischemia by HBO preconditioning.

Amitrole↗

PubMed2006

[Application of PCR-based tRNAval Pol III-shRNA expression cassettes in screening of efficient siRNA for inhibiting hepatitis B virus].

OBJECTIVE: To screen efficient siRNA for inhibiting hepatitis B virus using the technique of PCR-based tRNA(val) Pol III-shRNA expression cassettes (SECs). METHODS: Based on core gene sequence of HBV, five target sites of siRNA were designed. tRNAval Pol III-shRNA expression cassettes produced by one-step overlapping extension PCR strategy were co-transfected with HBV C gene and pC-EGFP plasmid into AD293 cells respectively. Forty-eight hours after transfection, fluorescence of HBVC-GFP protein was detected by fluorescence-activated cell sorting (FACS); HBV C mRNA was detected by semi-quantitative RT-PCR. HBV-producing HepG2. 2. 15 cells were transfected with selected SECs for 72 h, HBsAg and HBeAg in the cell culture medium were detected by radioimmunoassay assay (RIA). HBV pgRNA from cell total RNA was detected by semi-quantitative PCR. RESULT: Co-transfection with pC-GFP plasmid and SECs into AD293 cells resulted in inhibition expression of HBV C gene and decrease of EGFP fluorescence intensity. SEC-492i showed most significant inhibition effect on HBV C-EGFP expression compared with other SECs. Selected SEC-492i or SEC-282i targeting core gene could efficiently decrease expression of HBeAg and the level of HBV pgRNA in a dose-dependent manner. SEC-492i inhibited HBV replication and antigen expression in a more efficient way than SEC-282i at the same final concentration. CONCLUSION: The expressed shRNA, which targets sites on HBV C mRNA in 492i, is to have having most efficient RNAi effect. tRNAval Pol III-shRNA expression cassettes produced by one-step overlapping extension PCR strategy should be useful for identification of optimal siRNA.

Base Sequence↗

PubMed2006

[Inhibitory effect of mesenchymal stem cells carrying murine beta defensin 2 on malignant ascites in mice].

BACKGROUND & OBJECTIVE: Murine beta defensin 2 (MBD2) is a small antimicrobial peptide of the innate immune system. It provides a critical link between the innate immune system and the adaptive immune response. This study was to develop a set of MBD2-lentivirus system, and observe its inhibitory effect on malignant ascites in mice. METHODS: MBD2 RNA was extracted from kidneys of BALB/c mice, and the fragment of MBD2 was amplified by reverse transcription-polymerase chain reaction (RT-PCR). MBD2 plasmid was constructed, and the lentivirus system expressing MBD2 was produced in 293FT cells. Mesenchymal stem cells (MSCs) were then infected with MBD2-Lentivirus, and stably infected cells (MBD2-MSCs) were selected. The expression of MBD2 was detected by RT-PCR. The biological function of MBD2 was evaluated by dendritic cell (DC) migration experiment. BALB/c mice bearing intraperitoneal MethA tumors were injected intraperitoneally with MBD2-MSCs at the 2nd, 4th, 6th, and 8th day after inoculation. Ascites status and survival status of the mice were observed. Long-term survivors were inoculated intraperitoneally with MethA tumor cells again to observe their survival status. RESULTS: The expression of MBD2 in MBD2-MSCs was verified by RT-PCR. Numbers of migrated DCs were significantly increased in MBD2-MSC group than in normal saline (NS) group, MSC group, and null lentivirus (Null) group (43+/-8 vs. 8+/-1, 14+/-2, and 12+/-3, P<0.01). The volume of tumor ascites was significantly less in MBD2-MSC group than in NS group, MSC group, and Null group [(3.0+/-1.0) ml vs. (10.8+/-1.0) ml, (10.2+/-1.3) ml, and (9.8+/-1.6) ml, P<0.05]. Some mice in MBD2 group were still alive 40 days after tumor inoculation, while none in control groups survived up to 20 days after tumor inoculation (P<0.05). After inoculated with MethA tumor cells again, the mice in MBD2-MSC group still survived longer than those in control groups. CONCLUSION: MBD2-lentivirus gene therapy system is constructed successfully, and can inhibit the formation of malignant ascites.

Animals↗