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Xin Wu

Publications and source records attributed to Xin Wu.

At least 19 recordsLinked to original sources
PubMed2026

Comparative genomic characterization and antimicrobial resistance of bacteremia-causing Enterococcus faecium and Enterococcus faecalis in a Chinese hospital.

Enterococci are common commensals of the human gut and important opportunistic pathogens, with Enterococcus faecium and Enterococcus faecalis being the most clinically prevalent species. A significant epidemiological shift has emerged with an increasing clinical burden of E. faecium. To compare genomic evolution of E. faecium and E. faecalis, we performed whole-genome sequencing on 93 E. faecium and 32 E. faecalis isolates causing bloodstream infections at a single hospital (2022-2024). Analysis of patient demographics revealed that E. faecium infections originated from fewer sources than E. faecalis, with a higher proportion deriving from intra-abdominal infections. Multilocus sequence typing identified ST78 and ST789 as the predominant sequence types for E. faecium, whereas ST16 and ST179 were most common for E. faecalis. E. faecium carried more antimicrobial resistance genes and putative virulence marker (PVM)-type virulence genes than E. faecalis, with vancomycin resistance predominantly mediated by vanHAX (33/93, 35.5%) and a single E. faecalis isolate also carrying vanHAX (1/32, 3.1%); the structurally incomplete vanHMX gene cluster was detected in 11 E. faecium isolates. Pan-genome analysis indicated a larger core genome in E. faecalis compared to E. faecium, consistent with greater plasmid replicon diversity in the latter. Intra-host comparisons showed that two E. faecalis pairs from the same patient were clonally related, with one isolate acquiring a vanHAX plasmid conferring vancomycin resistance. In contrast, E. faecium isolates exhibited marked genomic diversity even among clonally related pairs. These findings suggest that E. faecium possesses greater genomic plasticity and adaptive potential to the clinical environment.IMPORTANCEThis study provides a detailed comparison of clinical and genomic features between Enterococcus faecium and Enterococcus faecalis from the same hospital setting. We show that E. faecium isolates, mainly ST78/ST789, carry more antimicrobial resistance genes and a higher number of putative virulence marker (PVM) genes than E. faecalis, reflecting their hospital-adapted nature. E. faecium also exhibits a smaller core genome and greater diversity of plasmid replicon types, indicating higher genomic plasticity and capacity for horizontal gene transfer. By contrast, E. faecalis retains a larger core genome and a set of classical virulence factors, and its within-host isolates are clonally related. These distinct genomic profiles help to understand how the two species adapt to clinical environments and may inform more targeted infection control strategies and resistance surveillance.

Enterococcus faecium↗
PubMed2006

Transplantation of human amniotic epithelial cells improves hindlimb function in rats with spinal cord injury.

BACKGROUND: Human amniotic epithelial cells (HAECs), which have several characteristics similar to stem cells, therefore could possibly be used in cell therapy without creating legal or ethical problems. In this study, we transplanted HEACs into the injured spinal cord of rats to investigate if the cells can improve the rats' hindlimb motor function. METHODS: HAECs were obtained from a piece of fresh amnion, labeled with Hoechst33342, and transplanted into the site of complete midthoracic spinal transections in adult rats. The rats (n = 21) were randomly divided into three groups: Sham-operation group (n = 7), cells-graft group (n = 7), and PBS group (n = 7). One rat of each group was killed for histological analysis at the second week after the transplantation. The other six rats of each group were killed for histological analysis after an 8-week behavioral testing. Hindlimb motor function was assessed by using the open-field BBB scoring system. Survival rate of the graft cells was observed at second and eighth weeks after the transplantation. We also detected the myelin sheath fibers around the lesions and the size of the axotomized red nucleus. A one-way ANOVA was used to compare the means among the groups. The significance level was set at P < 0.05. RESULTS: The graft HAECs survived for a long time (8 weeks) and integrated into the host spinal cord without immune rejection. Compared with the control group, HAECs can promote the regeneration and sprouting of the axons, improve the hindlimb motor function of the rats (BBB score: cells-graft group 9.0 +/- 0.89 vs PBS group 3.7 +/- 1.03, P < 0.01), and inhibit the atrophy of axotomized red nucleus [cells-graft group (526.47 +/- 148.42) microm(2) vs PBS group (473.69 +/- 164.73) microm(2), P < 0.01]. CONCLUSION: Transplantation of HAECs can improve the hindlimb motor function of rats with spinal cord injury.

Amnion↗
PubMed2006

Differential response between the p53 ubiquitin-protein ligases Pirh2 and MdM2 following DNA damage in human cancer cells.

Pirh2, a recently identified ubiquitin-protein ligase, has been reported to promote p53 degradation. Pirh2 physically interacts with p53 and promotes ubiquitination of p53 independently of MDM2. Like MDM2, Pirh2 is thought to participate in an autoregulatory feedback loop that controls p53 function. We have previously reported that Pirh2 was overexpressed in human and murine lung cancers as compared to uninvolved lung tissue. Pirh2 increase could potentially cause degradation of wildtype p53 and reduce its tumor suppression function in the lung tumor cells. Since Pirh2 has been reported to be transactivated by p53, however, the mechanisms by which a high level of Pirh2 expression is maintained in tumor cells despite low level of wildtype p53 protein are unclear. In order to evaluate p53 involvement in the transactivation of Pirh2, we evaluated Pirh2, MDM2, p53 and p21 expression with Western blot analysis and real time PCR after gamma irradiation or cisplatin DNA damage treatment using human cancer cell lines containing wildtype (A549, MCF-7), mutant (H719) and null (H1299) p53. Surprisingly, Pirh2 expression was not affected by the presence of wildtype p53 in the cancer cells. In contrast, MDM2 was upregulated by wildtype p53 in A549 and MCF-7 cells and was absent from the H1299 and the H719 cells. We conclude that Pirh2 operates in a distinct manner from MDM2 in response to DNA damage in cancer cells. Pirh2 elevation in p53 null cells indicates the existence of additional molecular mechanisms for Pirh2 upregulation and suggests that p53 is not the sole target of Pirh2 ubiquitin ligase activity.

Animals↗
PubMed2006

The prognostic significance of preoperative plasma levels of osteopontin in patients with hepatocellular carcinoma.

We aimed to evaluate the prognostic value of preoperative plasma osteopontin (OPN) levels in 101 patients with hepatocellular carcinoma (HCC) who underwent liver resection. Plasma OPN levels were detected by ELISA. The association of plasma OPN levels of patients with clinicopathological characteristics, tumor recurrence, and survival was analyzed. The median plasma OPN level of patients was 176.90 ng/ml (range 13.73-780.00 ng/ml), which was significantly higher than that of 24 healthy volunteers (63.74 ng/ml, range 12.20-122.32 ng/ml). Plasma OPN levels were significantly different in patients with different numbers of tumor nodules (168.18 and 217.11 ng/ml for single and multiple nodules, respectively; P = 0.002), different Edmondson's grades (201.24, 168.36, and 503.58 ng/ml for grades I, II, and III/IV, respectively; P = 0.015), and different TNM stages (168.16, 167.54, and 216.18 ng/ml for stages I, II, and III/IV, respectively; P = 0.016). Significantly higher plasma OPN levels were found in patients with a recurrence of HCC after resection, compared with those without recurrence (213.55 versus 153.70 ng/ml; P = 0.0013). A higher plasma OPN level was a leading independent prognostic factor for both overall survival (OS) and disease-free survival (DFS) in univariate and multivariate Cox models. This suggests that the preoperative plasma OPN level can be used as a predictive marker for HCC recurrence and may be helpful to assess the prognosis of patients with HCC after surgery.

Adult↗
PubMed2006

Effectiveness and dentin bond strengths of two materials for reinforcing thin-walled roots.

OBJECTIVES: To investigate the effectiveness of two restorative materials for reinforcing thin-walled roots and their microtensile bond strengths to root canal dentin. METHODS: Twenty-one decoronated maxillary central incisor roots were root filled and the canals enlarged to leave approximately 1.0 mm thick dentin walls. The roots were distributed randomly to three equal groups. Group 1 (control): a large tapered cast post-core was fabricated. Group 2 (BIS-CORE): a thick layer of dual-cured composite was placed in the post-hole before fabrication of a small-diameter tapered cast post-core. Group 3 (ChemFil Superior): a thick layer of glass-ionomer was placed, as before. Metal-ceramic crowns were fabricated for all teeth. Microtensile bond strength tests and optical and atomic force microscope observations were employed to examine adhesion between the two restorative materials and the root canal dentin. RESULTS: Mechanical loading (kN) demonstrated that composite 0.64 (S.D. 0.05), but not glass-ionomer 0.49 (0.05), significantly reinforced the fracture resistance of thin-walled roots, P<0.001. Microtensile bond strengths (MPa) were 21.7 (1.6) for composite and 12.9 (1.7) for glass-ionomer, P=002. SIGNIFICANCE: A thick intermediate layer of resin-bonded composite, sandwiched between the root dentin and a small-diameter cast Ni-Cr post or dowel, increased significantly the fracture resistance of the roots.

Adult↗
PubMed2006

[Fluorine-18 fluorodeoxyglucose-positron emission tomography imaging of carcinoma of cardia or fundus of stomach].

OBJECTIVE: To investigate the value of fluorine-18 fluorodeoxyglucose (FDG)-positron emission tomography (PET) in carcinoma of cardia or fundus of stomach. METHODS: From April 1999 to April 2005, 57 patients with carcinoma of cardia or fundus of stomach were imaged with FDG-PET. FDG-PET imaging were analyzed by visual method combined with semiquantitative analysis. The results were compared with pathological findings and follow-up results. RESULTS: In 29 untreated patients, 25 T(2) to T(4) tumors were all FDG avid and 4 T(1) cases showed nothing abnormal at the primary site. In 24 patients performed curative operation 40 resected enlarged lymph nodes beyond 1 cm were diagnosed correctly by FDG-PET. FDG-PET revealed distant metastases in 5 patients and corrected them from curative surgery candidates to late stage. In 28 treated patients FDG-PET confirmed 22 cases with recurrence or metastasis. CONCLUSIONS: FDG-PET has limited value in confirming T stage in carcinoma of cardia or fundus of stomach. It showed potential in N and M staging and predicting treatment response.

Adult↗
PubMed2006

Integrin receptor activation triggers converging regulation of Cav1.2 calcium channels by c-Src and protein kinase A pathways.

L-type, voltage-gated Ca2+ channels (CaL) play critical roles in brain and muscle cell excitability. Here we show that currents through heterologously expressed neuronal and smooth muscle CaL channel isoforms are acutely potentiated following alpha5beta1 integrin activation. Only the alpha1C pore-forming channel subunit is critical for this process. Truncation and site-directed mutagenesis strategies reveal that regulation of Cav1.2 by alpha5beta1 integrin requires phosphorylation of alpha1C C-terminal residues Ser1901 and Tyr2122. These sites are known to be phosphorylated by protein kinase A (PKA) and c-Src, respectively, and are conserved between rat neuronal (Cav1.2c) and smooth muscle (Cav1.2b) isoforms. Kinase assays are consistent with phosphorylation of these two residues by PKA and c-Src. Following alpha5beta1 integrin activation, native CaL channels in rat arteriolar smooth muscle exhibit potentiation that is completely blocked by combined PKA and Src inhibition. Our results demonstrate that integrin-ECM interactions are a common mechanism for the acute regulation of CaL channels in brain and muscle. These findings are consistent with the growing recognition of the importance of integrin-channel interactions in cellular responses to injury and the acute control of synaptic and blood vessel function.

Animals↗
PubMed2006

[Effects of puerarin on proliferation of vascular smooth muscle cells induced by thrombin].

OBJECTIVE: To investigate the effects of puerarin on the proliferation of vascular smooth muscle cells (VSMC) induced by thrombin and the mechanism thereof. METHODS: VSMCs were isolated from the thoracic aorta of a SD rat and cultured, then co-cultured with thrombin of the concentration 0.1, 0.3, 1.0, 3.0, and 10 U/L for 24 h, thrombin of the concentration of 1 U/L for 0, 6, 12, 24, 36, and 48 h respectively, or thrombin of the concentration of 1 U/L combined with puerarin of the concentrations of 1.5 x 10(-5), 1.5 x 10(-4), or 1.5 x 10(-3) mol/L for 24 h. Flow cytometry was used to detect the cell number and cell cycle. Western blotting was used to indicate the protein expression of the oncogenes c-fos and bcl-2 RT-PCR was used to evaluate the thrombin receptor (TR) mRNA expression. RESULTS: he numbers of the groups of VSMCs stimulated by 0.1, 0.3, 1.0, 3.0, and 10 U/L thrombin for 24 hours were 4.82 x 10(4)/ml +/- 0.11 x 10(4)/ml, 6.37 x 10(4)/ml +/- 0.09 x 10(4)/ml, 8.78 x 10(4)/ml +/- 0.08 x 10(4)/ml, 7.37 x 10(4)/ml +/- 0.07 x 10(4)/ml, and 5.28 x 10(4)/ml +/- 0.12 x 10(4)/ml respectively, all significantly higher than that of the control group (4.08 +/- 0.054 x 10(4)/ml, all P < 0.05). The effect of thrombin was in a dose-dependent manner within a concentration range of 0.1 - 1.0 U/L. The suppression rates of VSMC proliferation in the combination groups with puerarin of the concentrations of 1.5 x 10(-5), 1.5 x 10(-4), and 1.5 x 10(-3) mol/L were 10.9% +/- 1.6%, 32.1% +/- 3.3%, and 42.6% +/- 5.2% respectively in comparison with the thrombin group (all P < 0.05). The c-fos protein expression of the VSMCs after thrombin stimulation for 24 h increased by 156.0% +/- 11.3% (P < 0.05), and the bcl-2 protein expression of the VSMCs pretreated with puerarin of the concentrations of 1.5 x 10(-5), 1.5 x 10(-4), and 1.5 x 10(-3) mol/L, and then stimulated by thrombin was significantly lower than that of the VSMCs only stimulated by thrombin with the suppression rates of 20.7% +/- 2.1%, 31.6% +/- 5.2%, and 44.5% +/- 7.5% respectively (all P < 0.05). The bcl-2 protein expression of the VSMCs after thrombin stimulation for 24 h increased by 96.7% +/- 8.3% (P < 0.05), and the bcl-2 protein expression of the VSMCs pretreated with puerarin of the concentrations of 1.5 x 10(-5), 1.5 x 10(-4), and 1.5 x 10(-3) mol/L, and then stimulated by thrombin was significantly lower than that of the VSMCs only stimulated by thrombin with the suppression rates of 7.1% +/- 0.8%, 18.8% +/- 1.2%, and 39.6% +/- 6.4% respectively (all P < 0.05). The stimulation of thrombin increased the TR mRNA expression by 183.9% +/- 9.4%. The puerarin of the concentrations of 1.5 x 10(-5) mol/L and 1.5 x 10(-4) mol/L decreased the increase of TR mRNA expression induced by thrombin, however, without significant differences (both P > 0.05), and puerarin of the concentration of 1.5 x 10(-3) mol/L significantly suppressed the increase of TR mRNA expression induced by thrombin by 17.6% +/- 1.7% (P < 0.05). CONCLUSION: Puerarin suppresses the proliferation and DNA synthesis of VSMC induced by thrombin. The inhibitory effect of puerarin is closely related with the suppression of the protein expression of c-fos and bcl-2n, and partly related with the suppression of the TR mRNA expression.

Animals↗
PubMed2005

Sodium azide dilates coronary arterioles via activation of inward rectifier K+ channels and Na+-K+-ATPase.

Sodium azide (NaN(3)), a potent vasodilator, causes severe hypotension on accidental exposure. Although NaN(3) has been shown to increase coronary blood flow, the direct effect of NaN(3) on coronary resistance vessels and the mechanism of the NaN(3)-induced response remain to be established. To address these issues without confounding influences from systemic parameters, subepicardial coronary arterioles were isolated from porcine hearts for in vitro study. Arterioles developed basal tone at 60 cmH(2)O intraluminal pressure and dilated acutely, in a concentration-dependent manner, to NaN(3) (0.1 microM to 50 microM). The NaN(3) response was not altered by the nitric oxide synthase inhibitor N(G)-nitro-L-arginine methyl ester or endothelial removal. Neither inhibition of phosphoinositol 3-kinase and tyrosine kinases nor blockade of ATP-sensitive, Ca(2+)-activated, and voltage-dependent K(+) channels affected NaN(3)-induced dilation. However, the vasomotor action of NaN(3) was significantly attenuated in a similar manner by the inward rectifier K(+) (K(IR)) channel inhibitor Ba(2+), the Na(+)-K(+) ATPase inhibitor ouabain, or the guanylyl cyclase inhibitor 1H-[1,2,4]oxadiazolo[4,3,-a]quinoxalin-1-one (ODQ). Ba(2+), in combination with either ouabain or ODQ, nearly abolished the vasodilatory response. However, there was no additive inhibition by combining ouabain and ODQ. The NaN(3)-mediated vasodilation was also attenuated by morin, an inhibitor of phosphatidylinositolphosphate (PIP) kinase, which can regulate K(IR) channel activity. With the use of whole cell patch-clamp methods, NaN(3) acutely enhanced Ba(2+)-sensitive K(IR) current in isolated coronary arteriolar smooth muscle cells. Collectively, this study demonstrates that NaN(3), at clinically toxic concentrations, dilates coronary resistance vessels via activation of both K(IR) channels and guanylyl cyclase/Na(+)-K(+)-ATPase in the vascular smooth muscle. The K(IR) channels appear to be modulated by PIP kinase.

Animals↗
PubMed2005

[Tricuspid replacement and short-term follow-up: summary of 42 cases].

OBJECTIVE: To summarize the experience in tricuspid valve replacement (TVR). METHODS: From March 1997 to June 2004, 42 patients underwent isolated or combined TVR. Of the cases, 20 cases had prior cardiac operation (tricuspid valve had been repaired in 8). Indication of TVR: (1) irreparable and/or progressive tricuspid lesions; (2) intolerable tricuspid dysfunction after tricuspid repair. Instead of tricuspid repair, TVR was preferred when one of the following co-existed: moderate to severe increase of pulmonary vascular resistance; residual left heart dysfunction; previously repaired tricuspid. Simultaneous replacement after unsuccessful tricuspid repair had to be done in 14 cases. Valve replacement combinations were isolated TVR in 30 cases, tricuspid and aortic and mitral in 8, tricuspid and mitral in 3, tricuspid and aortic in 1. Fourteen tissue and 28 bi-leaflet mechanical valve prostheses were used in the tricuspid position. Other simultaneous procedures included corrections of congenital anomalies in 10 patients, repair of peri-prosthetic leakage, resection of myxoma and coronary artery bypass grafting in 1 case each. RESULTS: The operative mortality was 17%, and mortality 31%. Four patients died of low cardiac output. Massive cerebral thromboembolism, renal failure and dyscrasia was the cause of death in 1 case each. Post-operative heart function NYHA classification: 21 cases in I, 10 in II, 1 in III and 1 in IV. Late death occurred in 2 cases. CONCLUSIONS: TVR is preferable for a severely damaged or deformed tricuspid valve if the possibility of successful repairing is small, especially when accompanied pulmonary vascular disease and uncorrected lesions and/or dysfunction of the left heart co-exists.

Adolescent↗
PubMed2005

Neuronal sorting protein-related receptor sorLA/LR11 regulates processing of the amyloid precursor protein.

sorLA (Sorting protein-related receptor) is a type-1 membrane protein of unknown function that is expressed in neurons. Its homology to sorting receptors that shuttle between the plasma membrane, endosomes, and the Golgi suggests a related function in neuronal trafficking processes. Because expression of sorLA is reduced in the brain of patients with Alzheimer's disease (AD), we tested involvement of this receptor in intracellular transport and processing of the amyloid precursor protein (APP) to the amyloid beta-peptide (Abeta), the principal component of senile plaques. We demonstrate that sorLA interacts with APP in vitro and in living cells and that both proteins colocalize in endosomal and Golgi compartments. Overexpression of sorLA in neurons causes redistribution of APP to the Golgi and decreased processing to Abeta, whereas ablation of sorLA expression in knockout mice results in increased levels of Abeta in the brain similar to the situation in AD patients. Thus, sorLA acts as a sorting receptor that protects APP from processing into Abeta and thereby reduces the burden of amyloidogenic peptide formation. Consequently, reduced receptor expression in the human brain may increase Abeta production and plaque formation and promote spontaneous AD.

Alzheimer Disease↗
PubMed2005

GBA server: EST-based digital gene expression profiling.

Expressed Sequence Tag-based gene expression profiling can be used to discover functionally associated genes on a large scale. Currently available web servers and tools focus on finding differentially expressed genes in different samples or tissues rather than finding co-expressed genes. To fill this gap, we have developed a web server that implements the GBA (Guilt-by-Association) co-expression algorithm, which has been successfully used in finding disease-related genes. We have also annotated UniGene clusters with links to several important databases such as GO, KEGG, OMIM, Gene, IPI and HomoloGene. The GBA server can be accessed and downloaded at http://gba.cbi.pku.edu.cn.

Algorithms↗
PubMed2005

[Effects of acrylonitrile on the activities of antioxidant enzymes and levels of lipid peroxidation in rat testes].

OBJECTIVE: To explore the mechanism of male reproductive toxicity induced by acrylonitrile (ACN). METHODS: Male Sprague-Dawley rats were daily administrated ACN by intraperitoneal injection 5 times a week for 13 weeks at the dose of 0, 7.5, 15.0 and 30.0 mg/kg body weight, respectively. The rats were sacrificed and testes were removed at the end of 4, 8, 13 or 15 weeks, respectively. The activities of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) and glutathione S-transferase (GST) and the levels of glutathione (GSH) and malonaldehyde (MDA) were detected in testes. RESULTS: Following ACN treatment of 4 weeks, the levels of GSH in ACN 15.0 mg/kg and 30.0 mg/kg group were (7.44 +/- 0.77) mg/g pro and (6.95 +/- 0.77) mg/g pro respectively, and the activity of GSH-Px was (70.89 +/- 4.01) U/mg pro in 30.0 mg/kg group, all of which were significantly higher than the control group (P < 0.05, P < 0.01). After 8 weeks, the levels of GSH decreased to (2.50 +/- 0.94) mg/g pro in ACN 30.0 mg/kg group (P < 0.01); the activities of SOD increased to (102.08 +/- 16.08) NU/mg pro and (113.30 +/- 17.20) NU/mg pro in ACN 15.0 mg/kg and 30.0 mg/kg group (P < 0.01). After 13 weeks, the levels of GSH declined in ACN 15.0 mg/kg and 30.0 mg/kg group, and the activities of GST decreased in ACN 30.0 mg/kg group, and of GSH-Px decreased in both doses group. However, the level of MDA [(0.68 +/- 0.16) nmol/mg pro] were significantly higher in 30.0 mg/kg group than that in control group [(0.38 +/- 0.12) nmol/mg pro] (P < 0.01). 2 weeks after stopping ACN treatment, the level of GSH restored to normal but the levels of MDA or the activity of GSH-Px in 30.0 mg/kg group were still higher or lower respectively than those of control (P < 0.05). CONCLUSION: ACN may impair the balance of antioxidant system, thus induce lipid peroxidation damage to rat testes.

Acrylonitrile↗
PubMed2004

KIAA0008 gene is associated with invasive phenotype of human hepatocellular carcinoma--a functional analysis.

PURPOSE: To investigate the function of the KIAA0008 gene, one of the leading genes in the signature associated with hepatocellular carcinoma (HCC) metastasis selected by cDNA microarray, and especially its possible roles in invasion and metastasis of hepatocellular carcinoma. METHODS: Expression levels of KIAA0008 in 27 primary tumors and 23 matched non-tumor liver tissues from HCC patients, and four HCC cell lines with different metastatic potentials were detected by semi-quantitative RT-PCR and real-time RT-PCR. Recombinant expression plasmid vectors of the KIAA0008 gene were constructed and transfected into HCC cells. The subcellular localization of the KIAA0008 gene product and in vitro effects of KIAA0008 overexpression on proliferation and invasion of HCC cell line were also investigated. RESULTS: Expression levels of KIAA0008 in HCC tissues were statistically higher than those of paired non-tumorous liver tissues (P < 0.001, paired Wilcoxon test), and in HCCs with high invasiveness these were statistically higher than those with low invasiveness (P = 0.002, Mann-Whitney test). In the four HCC cell lines with an identical genetic background and stepwise higher invasiveness potentials, its expression was consistent with their invasiveness potential. The KIAA0008 gene product was concentrated on the nucleus and cell membrane of HCC cells, without any distribution in the cytoplasm. Overexpression of KIAA0008 in the MHCC97L cell line resulted in increased cell proliferation, colony formation, and invasion. CONCLUSIONS: KIAA0008 expression is associated with invasiveness of HCC; overexpression of KIAA0008 leads to a more invasive phenotype of HCC cell lines.

Adult↗
PubMed2004

Apolipoprotein E promotes astrocyte colocalization and degradation of deposited amyloid-beta peptides.

We have previously shown that apolipoprotein E (Apoe) promotes the formation of amyloid in brain and that astrocyte-specific expression of APOE markedly affects the deposition of amyloid-beta peptides (Abeta) in a mouse model of Alzheimer disease. Given the capacity of astrocytes to degrade Abeta, we investigated the potential role of Apoe in this astrocyte-mediated degradation. In contrast to cultured adult wild-type mouse astrocytes, adult Apoe(-/-) astrocytes do not degrade Abeta present in Abeta plaque-bearing brain sections in vitro. Coincubation with antibodies to either Apoe or Abeta, or with RAP, an antagonist of the low-density lipoprotein receptor family, effectively blocks Abeta degradation by astrocytes. Phase-contrast and confocal microscopy show that Apoe(-/-) astrocytes do not respond to or internalize Abeta deposits to the same extent as do wild-type astrocytes. Thus, Apoe seems to be important in the degradation and clearance of deposited Abeta species by astrocytes, a process that may be impaired in Alzheimer disease.

Amyloid beta-Peptides↗
PubMed2004

Lithium, a common drug for bipolar disorder treatment, regulates amyloid-beta precursor protein processing.

Lithium is one of the most widely used mood-stabilizing agents for the treatment of bipolar disorder. Although the underlying mechanism(s) of this mood stabilizer remains controversial, recent evidence linking lithium to neurotrophic/neuroprotective effects (Choi and Sung (2000) 1475, 225-230; Davies et al. (2000) 351, 95-105) suggests novel benefits of this drug in addition to mood stabilization. Here, we report that both lithium as well as valproic acid (VPA) inhibit beta-amyloid peptide (Abeta) production in HEK293 cells stably transfected with Swedish amyloid precursor protein (APP)(751) and in the brains of the PDAPP (APP(V717F)) Alzheimer's disease transgenic mouse model at clinically relevant plasma concentrations. Both lithium and VPA are known to be glycogen synthase kinase-3 (GSK3) inhibitors. Our studies reveal that GSK3beta is a potential downstream kinase, which modulates APP processing because inhibition of GSK3 activity by either a dominant negative GSK3beta kinase-deficient construct or GSK3beta antisense oligonucleotide mimics lithium and VPA effects. Moreover, lithium treatment abolished GSK3beta-mediated Abeta increase in the brains of GSK3beta transgenics and reduced plaque burden in the brains of the PDAPP (APP(V717F)) transgenic mice.

Alzheimer Disease↗