Rapid collapse of mitochondrial transmembrane potential in HL-60 cells and isolated mitochondria treated with anti-tumor 1,4-anthracenediones

Since synthetic analogs of 1,4-anthraquinone (AQ code number), such as AQ8, AQ9 and AQ10, can trigger cytochrome c release without caspase activation and retain their ability to induce apoptosis in multidrug-resistant (MDR) tumor cells, fluorescent probes of transmembrane potential have been used to determine whether these anti-tumor compounds might directly target mitochondria in cell and cell-free systems to cause the collapse of mitochondrial membrane potential (/Deltapsim) that is linked to permeability transition pore (PTP) opening. Using JC-1 dye, the abilities of various AQ analogs to induce the /Deltapsim in wild-type and MDR HL-60 cells are rapid (within 2.5-10 min), irreversible after drug removal, concentration dependent in the 0.256-10 micromol/l range and generally related to their anti-tumor activities in vitro. The /Deltapsim caused by AQ9 and AQ10, which are more potent than mitoxantrone, staurosporine and the reference depolarizing agent carbonyl cyanide m-chlorophenylhydrazone (CCCP) in HL-60 cells, are not prevented by caspase-2 or -8 inhibitors, suggesting that activations of these apical caspases upstream of mitochondria are not involved in this process. Antitumor AQ analogs (0.256-10 micromol/l) also mimic the abilities of the known depolarizing agents CCCP, alamethicin, gramicidin A and 100 micromol/l CaCl2 to directly induce within 15 min the /Deltapsim in isolated mitochondria prepared from mouse liver and loaded with rhodamine 123 dye. The fact that 20 micromol/l Ca2+, which is insufficient to trigger depolarization on its own, is required to reveal the depolarizing effect of AQ9 in isolated mitochondria suggests that anti-tumor AQ analogs might interact with the PTP to alter its conformation and increase its Ca2+ sensitivity. Indeed, such Ca2+-dependent /Deltapsim of isolated mitochondria treated with 1.6 micromol/l AQ9 or 100 micromol/l Ca2+ are blocked by ruthenium red. Daunorubicin (DAU) is unable to mimic the rapid /Deltapsim caused by anti-tumor AQ analogs within 2.5-40 min of treatment in HL-60 cells or isolated mitochondria. Moreover, the /Deltapsim caused by 1.6 micromol/l AQ9 or 100 micromol/l Ca2+ in isolated mitochondria are similarly blocked by cyclosporin A (CsA), bongkrekic acid and decylubiquinone, which prevent PTP opening, suggesting that, in contrast to DAU, anti-tumor AQ analogs that directly target mitochondria to trigger the Ca2+-dependent and CsA-sensitive /Deltapsim, might induce PTP opening and the mitochondrial pathway of apoptosis even in the absence of nuclear signals.     

Establishment and characterization of human hepatocellular carcinoma cell line FHCC-98

AIM: To establish a novel human hepatocellular carcinoma (HCC) cell line FHCC-98 from HCC tissue and to provide a suitable model for studying HCC occurrence, progress and metastasis.METHODS: Serially passaged cells were cultured and their morphologies were observed under light and electron microscope. Cytogenetic study was conducted by using flow cytometry and chromosome analysis. Expressions of tumor markers such as α-fetoprotein (AFP), cytokeratin (CK) and hepatoma metastasis-associated factor HAb18G/CD147 on the FHCC-98 cells were detected by immunocytochemistry or Western blotting. Lactic dehydrogenase (LDH) isoenzymes were detected by polyacrylamide gel electrophoresis (PAGE).Xenograft was performed by inoculating FHCC-98 cells into the flanks of nude mice.RESULTS: Morphology of FHCC-98 cells was the same as that of other malignant cells. The expressions of the cells were positive for HAb18G/CD147 and CK, and negative for AFP. Its population doubling time was 21.4 h. The cell DNA was tetraploid and the major chromosomes were triploid by cytogenetics analysis. The tumorigenicity in nude mice was 100%. PAGE showed four bands representing LDH2, LDH3,LDH4 and LDH5.CONCLUSION: FHCC-98 is a novel HCC cell line and an ideal cell model for further exploring the mechanism of hepatocellular carcinoma invasion and metastasis.     

脑出血患者血浆胶质纤维酸性蛋白浓度的变化

目的:揭示脑出血患者血浆胶质纤维酸性蛋白浓度的变化,探讨并评价其与疾病预后的相关性。方法:收集脑出血患者和同期健康体检合格者各86例。患者静脉血在脑出血后第1、2、3、5和7d获得,健康体检合格者静脉血在体检时获得,ELISA检测血浆胶质纤维酸性蛋白浓度。结果:脑出血患者血浆胶质纤维酸性蛋白浓度在脑出血后第1d升高,第2d到达高峰,后逐渐下降,均显著高于正常对照组(均P<0.01);与入院时美国国立卫生院神经功能缺损评分呈显著正相关(均P<0.01)。死亡组血浆胶质纤维酸性蛋白浓度均显著高于生存组(均P<0.01)。R0C曲线分析显示,脑出血后第1、2、3、5和7d血浆胶质纤维酸性蛋白浓度预测脑出血1月内死亡均有显著价值(均P<0.01),相比之下,第2d的血浆胶质纤维酸性蛋白浓度对脑出血1月内死亡的预测价值最高。结论:血浆胶质纤维酸性蛋白浓度脑出血后显著升高,与疾病预后显著相关。     

Quantile regression for the statistical analysis of immunological data with many non-detects

Background

Hemolytic uremic syndrome (HUS) leading to acute kidney failure, is a condition linked to the production of primarily Shiga toxin 2 (Stx2) by some E. coli serotypes. We have previously shown that Stx2 A subunit-specific human monoclonal antibody (HuMAb) 5C12, and B subunit-specific HuMAb 5H8 inhibit cultured cell death, and protect mice and piglets from fatal Stx2-intoxication. We have also shown that 5H8 blocks binding of Stx2 to its cell-surface receptor globotriaosyl ceramide (Gb₃), whereas Stx2 when complexed with 5C12 binds Gb₃ with higher affinity than Stx2. The mechanism by which 5C12 neutralizes Stx2 in vitro involves trapping of Stx2 in the recycling endosomes and releasing it into the extracellular environment. Because of the clinical implications associated with the formation of Stx2/antibody complexes and the potential for trapping and clearance through a severely damaged kidney associated with HUS, we investigated the likely site(s) of Stx2/antibody localization and clearance in intoxicated mice treated with antibody or placebo.

Results

Mice were injected with radiolabeled Stx2 (¹²⁵I-Stx2) 4 hours after administration of 5C12, 5H8, or phosphate buffered saline (PBS) and the sites of localization of labeled Stx2, were investigated 3, 24 and 48 hours later. The liver recorded statistically much higher concentrations of labeled Stx2 for groups receiving 5C12 and 5H8 antibodies after 3, 24 and 48?hours, as compared with the PBS group. In contrast, highest levels of labeled Stx2 were detected in the kidneys of the PBS group at all 3 sampling times. Mice receiving either of the two HuMAbs were fully protected against the lethal effect of Stx2, as compared with the fatal outcome of the control group.

Conclusions

The results suggest that HuMAbs 5C12 and 5H8 promoted hepatic accumulation and presumably clearance of toxin/antibody complexes, significantly diverting Stx2 localization in the kidneys, the target of Stx2 and the cause of HUS. This is in contrast to the fatal outcome of the control group receiving PBS. The results also confirm earlier observations that both HuMAbs are highly and equally protective against Stx2 intoxication in mice.     

Involvement of metabotropic glutamate receptor 5 in cardiomyocyte differentiation from mouse embryonic stem cells

Metabotropic glutamate receptors (mGluRs) are G-protein coupled receptors (GPCRs) activated by glutamate. The function of mGluRs is not restricted to the regulation of synaptic transmission. Although some roles of mGluR5 in mouse embryonic stem cells (ESCs) have been proposed, little is known about the significance of mGluR5 in cardiomyocyte differentiation from ESCs. We demonstrated that mGluR5 expression increased during cardiomyocyte differentiation. Activation of mGluR5 with (RS)-3, 5-dihydroxy phenylglycine (DHPG) promoted cardiomyocyte differentiation in a dose-dependent manner. DHPG significantly enhanced PI 3-kinase enhancer (PIKE) and PI3K p110α expression, but had no significant effect on Homer1b/c. The coexpression of PIKE or PI3K p110α together with Troponin T in embryoid bodies (EBs) treated with DHPG was elevated to 9.51% and 12.05%, respectively. Inhibition of mGluR5 with 2-methyl-6-(phenylethynyl)pyridine (MPEP) treating the ESCs, did hold back the cardiogenesis from the ESCs at the early differentiation stage. However, EBs applied by MPEP could not inhibit cardiomyocyte differentiation. Small interfering RNA (siRNA) of mGluR5 blocked cardiomyocyte differentiation by repressing PIKE and PI3K p110α expression, but had no notable influence on Homer1b/c. mGluR5 siRNA also decreased the DHPG-induced Ca2? transient peak amplitude in the isolated ESC-derived cardiomyocytes. The amplitude of Ca2? oscillation was reduced by ～90% with si-mGluR5-3 compared with si-control. The protein expression of T-type Ca2? channel and L-type Ca2? channel was decreased in si-mGluR5-3-treated EBs. Taken together, these results revealed that mGluR5/PIKE/PI3K signaling pathway was involved in cardiomyocyte differentiation from ESCs. The key function of mGluR5 is probably associated with cardiogenesis and Ca2? signal in ESC-derived cardiomyocytes.     

Molecular characterization of the newly identified human parvovirus 4 in the family Parvoviridae

Human parvovirus 4 (PARV4) is an emerging human virus, and little is known about the molecular aspects of PARV4 apart from its incomplete genome sequence, which lacks information of the termini. We analyzed the gene expression profile of PARV4 using a nearly full-length HPV4 genome in a replication competent system in 293 cells. We found that PARV4 utilizes two promoters to transcribe non-structural protein- and structural protein-encoding mRNAs, respectively, which were polyadenylated at the right end of the genome. Three major proteins, including the large non-structural protein NS1a, whose mRNA is spliced, and capsid proteins VP1 and VP2, were detected. Additional functional analysis of the NS1a revealed its capability to induce cell cycle arrest at G2/M phase in ex vivo-generated human hematopoietic stem cells. Taken together, our characterization of the molecular features of PARV4 suggests that PARV4 represents a new genus in the family Parvoviridae.     

Development of a smart garment to reduce kyphosis during daily living

Many of the aches and pains of adults are the result of the long-term effects of bad posture or body misalignment. Postural kyphosis in adolescence, which is an excessive rounding of the upper spine, may be one of the effects of poor standing and sitting habits. A smart garment, consisting of a harness and two data-sensor loggers, was developed to monitor and provide vibration feedback to wearers to improve their posture during daily activities. Laboratory tests verified that the garment could provide an accuracy of 2?±?2° during static measurement and 3?±?2° during stable or slowly changing posture activities and 4?±?4° during rapidly changing posture activities. Four volunteers wore the system for 3?h per day and for 4 consecutive days. The feedback was provided on the last 2?days and the kyphotic angle reduced by 8?±?1° and 8?±?2° on the last 2?days, respectively. Although the long-term effects of reminding the subjects?? posture is still not clear, a short-term result shows promise that the smart garment may be able to improve the kyphosis.