[Analysis of epidemiological characteristics and risk factors of catheter-associated urinary tract infections in patients with perineal and/or hip burns].

Objective: To explore the epidemiological characteristics and risk factors of catheter-associated urinary tract infections in patients with perineal and/or hip burns. Methods: This study was a retrospective case series study. From January 2018 to December 2022, 260 patients with perineal and/or hip burns and urinary catheters indwelling who met the inclusion criteria were admitted to the Department of Burns and Wound Repair of the Second Affiliated Hospital of Zhejiang University School of Medicine, including 192 males and 68 females, aged 20-93 years. The total incidence of catheter-associated urinary tract infections in patients with perineal and/or hip burns, the detection of pathogenic bacteria, and the resistance of major Gram-negative and Gram-positive bacteria to commonly used antimicrobial drugs in clinic were recorded. According to whether catheter-associated urinary tract infection occurred or not, the patients were divided into infection group (43 cases) and non-infection group (217 cases). The basic conditions including gender, age, total burn area, depth of perineal burn, depth of hip burn, and burn site on admission, complications of diabetes mellitus, inhalation injury, and hypoproteinaemia, invasive operations including tracheotomy and non-perineal/hip debridement/skin transplantation surgery, duration of catheter retention, number of urethral catheterization, and bladder irrigation of patients between the two groups were compared, and the independent risk factors influencing the occurrence of catheter-associated urinary tract infections in patients with perineal and/or hip burns were screened. Results: The total incidence of catheter-associated urinary tract infections in patients with perineal and/or hip burns in this study was 16.5% (43/260). The pathogens detected were predominantly Gram-negative, followed by fungi; the main Gram-negative bacterium was Klebsiella pneumoniae, and the main Gram-positive bacterium was Enterococcus faecalis. The resistance rates of Klebsiella pneumoniae to amoxicillin/clavulanic acid, amitraz, amikacin, ciprofloxacin, ceftriaxone, and levofloxacin were higher than 70.0%, the resistance rates of Klebsiella pneumoniae to cefoxitin, cefoperazone/sulbactam, cefepime, meropenem, imipenem, and piperacillin/tazobactam ranged from 56.3% to 68.8%, and the resistance rates of Klebsiella pneumoniae to ceftazidime and tigecycline were lower than 50.0%. The resistance rates of Enterococcus faecalis to ciprofloxacin and penicillin were both 85.7%, the resistance rates of Enterococcus faecalis to erythromycin, clindamycin, moxifloxacin, and tetracycline ranged from 14.3% to 57.1%, and the resistance rates of Enterococcus faecalis to linezolid, tigecycline, and vancomycin were all 0. The differences were statistically significant between the two groups in terms of gender, status of complication of hypoproteinaemia, depth of perineal burn, status of non-perineal/hip debridement/skin transplantation surgery, status of bladder irrigation, number of urethral catheterization, and duration of catheter retention of patients (with χ2 values of 7.80, 4.85, 10.68, 9.11, and 16.48, respectively, and Z values of -4.88 and -5.42, respectively, P<0.05). There were no statistically significant differences in the age, total burn area, complications of diabetes mellitus and inhalation injury, burn site, depth of hip burns, and status of tracheotomy of patients between the two groups (P>0.05). Multifactorial logistic regression analysis showed that gender, deep partial-thickness perineal burns, non-perineal/hip debridement/skin transplantation surgery, bladder irrigation, and duration of catheter retention were the independent risk factors for catheter-associated urinary tract infections in patients with perineal and/or hip burns (with odds ratios of 2.86, 2.63, 2.79, 2.34, and 1.04, respectively, with 95% confidence intervals of 1.21-6.73, 1.03-6.71, 1.03-7.59, 1.05-5.22, and 1.02-1.06, respectively, P<0.05). Conclusions: The incidence of catheter-associated urinary tract infections is high in patients with perineal and/or hip burns, with Klebsiella pneumoniae as the predominant pathogenic bacteria having a high resistance rate to commonly used antimicrobial drugs in clinic. Gender, deep partial-thickness perineal burns, non-perineal/hip debridement/skin transplantation surgery, bladder irrigation, and duration of catheter retention are the independent risk factors for catheter-associated urinary tract infections in patients with perineal and/or hip burns.

[Study on static parameters of internal nasal valve in 3-dimensional model of nasal cavity space].

Objective: To identify the internal nasal valve (INV) and to evaluate its key parameters in the established 3D models of nasal cavity space via Mimics from CT images, in order to provide evidence for quantitative diagnosis of nasal valve compromise. Methods: A total of 32 Han adults without nasal diseases who underwent maxillofacial CT test in Shanghai Ninth People's Hospital from January 2015 to December 2018 were retrospectively recruited, including 16 males and 16 females, with the age ranged from 20 to 80 years (50% age<50 years old). Maxillofacial CT images were used to create 3D model of nasal cavity space. The INV was identified and the following parameters were measured: the angle between the INV and the nasal bone (θINV-B), unilateral cross-sectional area of the INV (AINV-R, AINV-L), total cross-sectional area of the INV (AINV), unilateral height of the INV (HINV-R, HINV-L), unilateral nasal valve angle (αINV-R, αINV-L), and the sum of nasal valve angle (αINV). The AINV in our study was compared with the results of the previously adopted planes (PlaneC, perpendicular to the hard palate and PlaneB, plane perpendicular to the nasal bone). The parameters above were compared among genders, age and race groups. SPSS 26 and GraphPad Prism 9 software were used for statistical analysis and mapping of data. Results: The AINV in our study was (214.87±52.94) mm², which was significantly less than that of PlaneC (254.97±47.80) mm² and PlaneB (226.07±57.36) mm². The measured parameters were as follows: θINV-B was (82.07±7.06)°; AINV-R was (112.66±31.39) mm²; AINV-L was (102.21±27.14) mm²; AINV was (214.87±52.94) mm²; HINV-R was (24.87±4.62) mm; HINV-L was (24.35±4.86) mm; αINV-R was (20.48±2.99)°; αINV-L was (19.65±3.82)°; αINV was (40.13±6.24)°. The AINV-R was larger than AINV-L (t=2.33, P<0.05); The HINV, AINV-R, AINV-L and AINV of males were more than those of females (t value was 5.77, 3.21, 2.91 and 3.52, respectively, all P<0.01). The AINV of the young group (<50 years) was larger than that of the old group (t=2.83, P<0.01); The θINV-B was different between the Han people and the Caucasian (t=2.92,P<0.01). The αINV of the Han people was larger than that of Caucasians (Z=-6.92, P<0.01), but the HINV was smaller (Z=-3.89, P<0.01). Conclusion: The AINV carried out in 3D models of nasal cavity space is significantly smaller than that obtained by the previous methods of CT evaluation. INV static parameters differ among genders, age and race groups.

[Laterally extended endopelvic resection for advanced or recurrent gynecological malignancies: clinicopathological analysis].

To explore the feasibility and safety of laterally extended endopelvic resection (LEER) for advanced and recurrent gynecological malignancies with pelvic sidewall involvement and to evaluate this therapeutic potential of this novel salvage treatment. The clinicopathological data of 5 patients with gynecological malignancies who received laparoscopic LEER treatment in Obstetrics and Gynecology Hospital of Fudan University from January 2019 to September 2021 were retrospectively analyzed, including 3 cases of recurrent cervical cancer, 1 case of primary advanced endometrial cancer and 1 case of pelvic aggressive angiomyxoma. Among them, four patients achieved complete resection (R0) with a negative resection margin; the other patient with recurrent cervical cancer did not complete surgery because of the extreme risk of continuing surgery. The median operation time was 345 (225-482) minutes and the median blood loss was approximately 300 (200-600) ml. Complications occurred in three patients, including lymphocysts, urinary tract infections, and deep venous thrombosis of the lower extremities. Within a median follow-up time of 283 (128-715) days, 4 patients survived tumor-free, and 1 patient died. The high rate of complete resection (R0) and the encouraging oncological outcomes suggest that LEER may be an alternative treatment option for patients with advanced and recurrent gynecological malignancies involving the pelvic sidewall.

Determinants of SARS-CoV-2 receptor gene expression in upper and lower airways.

The recent outbreak of the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), which causes coronavirus disease 2019 (COVID-19), has led to a worldwide pandemic. One week after initial symptoms develop, a subset of patients progresses to severe disease, with high mortality and limited treatment options. To design novel interventions aimed at preventing spread of the virus and reducing progression to severe disease, detailed knowledge of the cell types and regulating factors driving cellular entry is urgently needed. Here we assess the expression patterns in genes required for COVID-19 entry into cells and replication, and their regulation by genetic, epigenetic and environmental factors, throughout the respiratory tract using samples collected from the upper (nasal) and lower airways (bronchi). Matched samples from the upper and lower airways show a clear increased expression of these genes in the nose compared to the bronchi and parenchyma. Cellular deconvolution indicates a clear association of these genes with the proportion of secretory epithelial cells. Smoking status was found to increase the majority of COVID-19 related genes including ACE2 and TMPRSS2 but only in the lower airways, which was associated with a significant increase in the predicted proportion of goblet cells in bronchial samples of current smokers. Both acute and second hand smoke were found to increase ACE2 expression in the bronchus. Inhaled corticosteroids decrease ACE2 expression in the lower airways. No significant effect of genetics on ACE2 expression was observed, but a strong association of DNA- methylation with ACE2 and TMPRSS2- mRNA expression was identified in the bronchus.

Leptin promotes proliferation and inhibits apoptosis of prostate cancer cells by regulating ERK1/2 signaling pathway.

OBJECTIVE: The aim of this study was to investigate the effect of leptin (Lep) on the proliferation, invasion and apoptosis of prostate cancer cells through the extracellular regulated protein kinase 1/2 (ERK1/2) signaling pathway. MATERIALS AND METHODS: Prostate cancer DU145 cells in the logarithmic growth phase were randomly divided into Lep (10, 20, 40, 80, 160 and 320 ng/mL) groups and blank control (Con) group. After culture, the cells were treated for 6 h, 12 h and 24 h, respectively. The effects of Lep on the proliferation and invasion of DU145 cells were detected via methyl thiazolyl tetrazolium (MTT) assay and transwell chamber assay, respectively. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was carried out to examine the messenger ribonucleic acid (mRNA) expressions of ERK1/2, b-cell lymphoma 2 (Bcl-2) and Bcl-2-associated X protein (Bax) in DU145 cells after Lep treatment for 24 h. Thereafter, immunofluorescence assay was performed to detect the localization of ERK1/2 protein in prostate cancer DU145 cells. In addition, the expressions of phosphorylated (p)-ERK, ERK1/2 and apoptosis-related proteins, Bcl-2, Bax and cleaved cysteinyl aspartate specific proteinase (c-Caspase 3) in prostate cancer DU145 cells after treatment with different concentrations of Lep for 24 h were examined by Western blotting. RESULTS: MTT assay results showed that the proliferation rate of DU145 cells increased significantly at 6 h, 12 h and 24 h after 5-320 ng/mL of Lep treatment (p<0.05). Transwell assay manifested that the number of invasive cells was significantly raised after Lep treatment for 24 h (p<0.05). Meanwhile, the invasion ability of cells increased gradually with the elevation of Lep concentration. Subsequent qRT-PCR results demonstrated that after treatment with different concentrations of Lep, the mRNA expressions of ERK1/2 and Bcl-2 rose markedly (p<0.05). However, the mRNA expression of Bax was remarkably down-regulated (p<0.05) with the increase of Lep concentration in a concentration-dependent manner. According to the detection using a laser scanning confocal microscope, ERK1/2 red fluorescence showed punctiform aggregation, which was gradually raised with the increase of Lep concentration for 24 h. Moreover, Western blotting results denoted that with the increase of Lep concentration, the protein expressions of p-ERK, ERK1/2 and Bcl-2 were notably elevated (p<0.05), while those of Bax and c-Caspase 3 were distinctly reduced (p<0.05). CONCLUSIONS: Lep activation induces the proliferation, promotes the invasion and inhibits the apoptosis of prostate cancer cells through the ERK1/2 signaling pathway.

[Application of gastric pull up and complex laryngotracheal flap to reconstruct the circumferencial defect after resection of the hypopharyngeal and cervical esophageal cancers].

Objective: To evaluate the efficacy of gastric pull-up and complex laryngotracheal flap in reconstruction for circumferencial defects after resection of hypopharyngeal and cervical esophageal cancers. Methods: A total of 163 cases (152 males, 11 females) with circumferencial defect after resection of hypopharyngeal and cervical esophageal cancers received reconstructive surgeries by gastric pull-up (42 cases) and complex laryngo-tracheal flaps (121 cases), of them 115 cases simultaneously underwent unilateral neck dissection and 20 cases had bilateral neck dissection. Postoperative radiotherapy was used in 67 cases, with a dosage of 40-60 Gy. Results: There were 127 (77.9%) cases with positive metastatic lymph nodes. Of 42 patients with gastric pull-up reconstruction, 39 cases (92.8%) recovered the function of oral swallowing after operation, and 8 cases with cervical esophageal cancer recovered the functions of oral swallowing and speech after gastroesophageal anastomosis reconstruction. There were 3 (7.1%) cases died of surgery and 8 cases with surgical complications. Reconstruction of upper digestive tract with combined laryngotracheal flap was successful in all 121 cases, with recovered oral swallowing function after operation. No patient died of surgery but 24 cases had complications, mainly pharynx skin fistula or wound infection, which were cured by conservative treatments. The 1-, 3- and 5-year survival rates for 163 patients were 69.8%, 50.5% and 34.3%, respectively. The independent factors for prognosis included T4 (P<0.001) and N+ (P=0.042). Conclusions: The complex of laryngotracheal flap with pectoralis major myocutaneous flap is suitable for most advanced hypopharyngeal cancer after resection of the tumor and reconstruction of circumferencial defect. It is simple technology, low and slight complication rate. The minority is not suitable for the application of pectoralis major myocutaneous flap can be used instead of free anterolateral thigh flap. Gastric pull-up for reconstruction of upper digestive tract is suitable for most patients with cervical esophageal cancer and hypopharyngeal carcinoma invading the cervical esophagus who are not suitable for laryngotracheal flap reconstruction, with good swallowing function after surgery. However, it is prudent to choose operative indications because of serious surgical trauma and risks for complications.

Proteomic alterations of fibroblasts induced by ovarian cancer cells reveal potential cancer targets.

The common spread pattern of ovarian cancer is peritoneal implantation. The growth of the shed ovarian cancer cells in the peritoneal cavity is closely related to the tumor microenvironment. Cancer-associated fibroblasts are vital in the tumor microenvironment. It is not clearly defined that the protein expression alters during the activating process of fibroblasts. This study detected the protein alterations in fibroblasts induced by ovarian cancer cells and explored the potential biological relevance through two-dimensional gel electrophoresis and mass spectrometry. Our data showed that the level of CENPE, BAG2, SOD2, GDI2, CORO1C, CFL1, DSTN, CALD1, PHGDH, PDHA1, AKR1B1, TST and TBCA proteins were significantly up-regulated in the fibroblasts co-cultured with ovarian cancer cells, whereas HSPB1, P4HB and VIM were significantlydown-regulated. However, only BAG2, SOD2 and CORO1C proteins were confirmed to be significantly increased by western blot analysis. The differentially expressed proteins were mainly involved in metabolic processes, cellular component organization, responses to stimulus, multicellular organismal processes, localization, protein depolymerization, cellular senescence and the mitotic pathway. These data demonstrated that fibroblasts had an altered protein expression pattern after being induced by ovarian cancer cells, and participated in multiple cell processes resulting in tumor progression. The differentially expressed proteins should be considered as targets for cancer treatment.

[Study on the metastatic sequence of cervix lymph node in hypopharyngeal carcinoma].

Objective: To investigate the metastatic sequence of cervical lymph node in hypopharyngeal carcinoma aimed at guiding neck exploration. Methods: Seventy-five serial sections of integrally dissected lateral neck specimens from 67 patients of hypophayryngeal carcinoma were histopathologically observed, and the metastatic sequence of cervical lymph node of hypophayryngeal carcinoma were analysed. Results: In 75 integrally dissected lateral neck specimens, 63 laterals were found to occur cervical lymph node metastases, the metastatic ratio was 84.0%. The analytic result of 63 dissected lateral neck specimens with positive lymph nodes showed that the metastatic lymph node ratio in descending order was level Ⅱ (90.5%), level Ⅲ (76.2%), level Ⅳ (41.3%), level Ⅴ (15.9%), level Ⅰ (7.9%) and level Ⅵ (3.2%). The metastatic ratio of lymph node between level Ⅰ~Ⅵ were significantly different from each other (P<0.01). When the tumor metastasized to one cervical lymph node, this could be found in levels Ⅱ or Ⅲ, when metastasized to two cervical lymph nodes, these could be found in levels Ⅱ, Ⅲ, Ⅳ, and when metastasized to more than 5 of cervical lymph nodes, these could be found in levels Ⅱ, Ⅲ, Ⅳ, Ⅴ, Ⅰand Ⅵ. According to the occurring sequence, metastatic ratio and number of cervical lymph node metastasis (LNM), levels Ⅱ and Ⅲ were identified as the first station, level Ⅳ was the second station and levels Ⅴ, Ⅰ and Ⅵ were the third station of cervical LNM in hypopharyngeal carcinoma. Conclusion: The confirmation of metastatic sequence of cervical lymph node in hypophayryngeal carcinoma provides a reliable evidence for neck lymph node dissection and reference value for clinic therapy.

Gene expression profiling analysis of the role of miR-22 in clear cell ovarian cancer.

This study aimed to investigate the role and potential mechanism of miR-22 in clear cell ovarian cancer (CCOC) progression. The gene expression profile of GSE16568, including 3 CCOC samples with miR-22 overexpression and 3 negative controls, was downloaded from the Gene Expression Omnibus database. Differentially expressed genes (DEGs) were screened using the limma package in R. Gene Ontology (GO) and pathway enrichment analysis of DEGs were performed by using The Database for Annotation, Visualization and Integrated Discovery (DAVID). Furthermore, protein-protein interaction (PPI) network of the DEGs was constructed using the Search Tool for the Retrieval of Interacting Genes (STRING) database. Besides, the miR-22-mRNA interaction pairs were predicted to explore the critical genes involved in the cancer. Totally, 95 up-regulated DEGs and 51 down-regulated DEGs were identified. The DEGs were enriched in different GO terms and pathways. The up-regulated genes cyclin-dependent kinases (CDK6), MDM2 oncogene, E3 ubiquitin protein ligase (MDM2), and thrombospondin 1 (THBS1) were involved in the p53 signaling pathway. The up-regulated gene FBJ murine osteosarcoma viral oncogene homolog (FOS) was a hub protein in the PPI network of the DEGs. The down-regulated DEGs including lymphoid enhancer-binding factor 1 (LEF1) and v-myb avian myeloblastosis viral oncogene homolog (MYB) were mainly associated with immunity. Nine DEGs as target genes were identified to be recognized by miR-22. Our study suggested that several key genes such as CDK6, MDM2, LEF1, MYB, and FOS that involved in different pathways including p53 signaling pathway were associated with CCOC progression. miR-22 may play an essential role in cell migration and invasion in CCOC through targeting responsive genes.

The histone deacetylase SIRT6 inhibits ovarian cancer cell proliferation via down-regulation of Notch 3 expression.

OBJECTIVE: SIRT6 belongs to the NAD+-dependent class III deacetylase sirtuin family. Accumulating evidences have supported the critical role of SIRT6 in the proliferation, differentiation, cell cycle progression and apoptosis of cancer cells. The present study aims to determine the expression of SIRT6 in human ovarian cancer tissues and further investigate its the biological effect in ovarian cancer. MATERIALS AND METHODS: Real time PCR and western blot were performed to examine the mRNA and protein levels SIRT6 in human ovarian cancer tissues and normal tissues. The proliferation of ovarian cancer cells was determined using MTT methods. Small interfering RNA (siRNA) technology was used to down-regulate the expression of SIRT6 and Notch 3. RESULTS: We found that the SIRT6 expression was significantly reduced in human ovarian cancer tissues compared to the normal tissues. Furthermore, our data showed that overexpression of SIRT6 inhibited the proliferation of ovarian cancer cells SKOV3 and OVCAR3. By contrast, down-regulation of SIRT6 enhanced ovarian cancer cells growth. In addition, our study showed that SIRT6 suppressed the expression of Notch 3 both at the mRNA and protein levels in ovarian cancer cells. CONCLUSIONS: Our findings indicated that SIRT6 inhibited the proliferation of ovarian cancer cells through down-regulation of Notch 3 expression, and might provide novel therapeutic targets for ovarian cancer therapy.

Combined NgR vaccination and neural stem cell transplantation promote functional recovery after spinal cord injury in adult rats.

AIMS: after spinal cord injury (SCI), there are many adverse factors at the lesion site such as glial scar, myelin-derived inhibitors, cell loss and deficiency of neurotrophins that impair axonal regeneration. Therefore, combination therapeutic strategies might be more effective than a single strategy for promoting functional recovery after SCI. In the present study, we investigated whether a Nogo66 receptor (NgR) vaccine, combined with neural stem cell (NSC) transplantation, could promote better functional recovery than when NgR vaccine or NSCs were used alone. METHODS: adult rats were immunized with NgR vaccine at 1 week after a contusive SCI at the thoracic level, and the NSCs, obtained from green fluorescent protein transgenic rats, were transplanted into the injury site at 8 weeks post injury. The functional recovery of the animals under various treatments was evaluated by three independent behavioural tests, that is, Basso, Beattie and Bresnahan locomotor rating scale, footprint analysis and grid walking. RESULTS: the combined therapy with NgR vaccination and NSC transplantation protected more ventral horn motor neurones in the injured spinal cord and greater functional recovery than when they were used alone. Furthermore, NgR vaccination promoted migration of engrafted NSCs along the rostral-caudal axis of the injured spinal cords, and induced their differentiation into neurones and oligodendrocytes in vivo. CONCLUSIONS: the combination therapy of NgR vaccine and NSC transplantation exhibited significant advantages over any single therapy alone in this study. It may represent a potential new therapy for SCI.

Plasticity of ovarian cancer cell SKOV3ip and vasculogenic mimicry in vivo.

The aim of this study is to investigate the plasticity of human epithelial ovarian cancer cell SKOV3ip and formation of vasculogenic mimicry (VM) in vivo. SKOV3ip was transfected with lentiviral vector carrying green fluorescence protein (GFP). Female nude mice were implanted intraperitoneally with GFP-labled SKOV3ip. When the transplanted tumor reached a volume of approximately 1 cm(3), paraffin-embedded, formaldehyde-fixed tissue was prepared and stained with hematoxylin and eosin (H & E). Tumor tissues were also studied by electron microscopy and fluorescence microscopy. The results of H & E staining, electron microscopy, and fluorescence microscopy indicated SKOV3ip formed patterned networks with erythrocytes in them, in the absence of vascular epithelial cells, which was a sign that SKOV3ip engaged in VM in vivo. Expression of vascular epithelium marker CD31 was investigated by immunohistochemical staining, immunofluorescence assay, semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR), and flow cytometric analysis (FACS). Factor VIII and vascular endothelial growth factor (VEGF) were also analyzed by FACS. Weak and focal CD31 immunohistochemical staining was found along the channels of tumor cells. Immunofluorescence assay and RT-PCR demonstrated that CD31 was expressed in primary-cultured SKOV3ip. CD31 and Factor VIII, but not VEGF were detected in primary-cultured SKOV3ip by FACS. The present study has shown that human ovarian cancer cell line SKOV3ip may be able to express some specific markers of vascular epithelial cells and has plasticity to form VM in vivo. In the following study, we indicated that hypoxia-inducible factor (HIF)-1alpha inhibitor, rapamycin, could possibly prevent VM and phenotype transformation of SKOV3ip, reflected by down-regulating expression of CD31 and Factor VIII. HIF-1alpha protein expression correlated with CD31 and Factor VIII protein expression in SKOV3ip. These results indicated that VM might be associated with HIF-1alpha.

[Molecular cloning of full length capsanthin/capsorubin synthase homologous gene from orange (Citrus sinensis)].

The complete sequence of orange homologous capsanthin/capsorubin synthase gene is 3788 bp long with a coding sequence of 1512 bp, which encodes a polypeptide of 503 amino acids. The 5' upstream sequence is 1721 bp long and the 3' downstream sequence is 555 bp long. The amino acid sequence of this gene is 78% and 69% identical to the genes from carrot and pepper, respectively. It is also partially homologous to plant neoxanthin synthase, lycopene beta-cyclase and lycopene epsilon cyclase genes. Isolation of the gene provides a framework for elucidation of the mechanisms involved in inability of citrus to produce capsanthin and capsorubin.

Human angiogenin is rapidly translocated to the nucleus of human umbilical vein endothelial cells and binds to DNA.

Human angiogenin is translocated to the nucleus of human umbilical vein endothelial cells in a time-dependent manner. Exogenous angiogenin appears in the nucleus in 2 min, reaches saturation in 15 min when 85% of the internalized angiogenin is in the nuclei, and remains associated with the nucleus for at least 4 h. Endothelial cells cultured at low density have a much higher capacity to translocate angiogenin to the nucleus than do those cultured at high density. This observation is consistent with previous findings that both the ability of endothelial cells to proliferate in response to angiogenin and the expression of an angiogenin receptor on the cell surface depend on cell density. Nuclear (125)I-angiogenin is not degraded and is neither spontaneously dissociated nor replaced by unlabeled angiogenin. It is, however, released by deoxyribonuclease I, but not by ribonuclease A, suggesting that angiogenin binds to DNA in the nucleus. These results suggest that in addition to acting as a ribonuclease, angiogenin may play a role in regulating gene expression by direct binding to DNA.

Caspase-8 is required for cell death induced by expanded polyglutamine repeats.

We show here that caspase-8 is required for the death of primary rat neurons induced by an expanded polyglutamine repeat (Q79). Expression of Q79 recruited and activated caspase-8. Inhibition of caspase-8 blocked polyglutamine-induced cell death. Coexpression of Q79 with the caspase inhibitor CrmA, a dominant-negative mutant of FADD (FADD DN), Bcl-2, or Bcl-xL, but not an N-terminally tagged Bcl-xL, prevented the recruitment of caspase-8 and inhibited polyglutamine-induced cell death. Furthermore, Western blot analysis revealed the presence of activated caspase-8 in the insoluble fraction of affected brain regions from Huntington's disease (HD) patients but not in those from neurologically unremarkable controls, suggesting the relocation and activation of caspase-8 during the pathogenesis of HD. These results suggest an essential role of caspase-8 in HD-related neural degenerative diseases.

Cleavage of BID by caspase 8 mediates the mitochondrial damage in the Fas pathway of apoptosis.

We report here that BID, a BH3 domain-containing proapoptotic Bcl2 family member, is a specific proximal substrate of Casp8 in the Fas apoptotic signaling pathway. While full-length BID is localized in cytosol, truncated BID (tBID) translocates to mitochondria and thus transduces apoptotic signals from cytoplasmic membrane to mitochondria. tBID induces first the clustering of mitochondria around the nuclei and release of cytochrome c independent of caspase activity, and then the loss of mitochondrial membrane potential, cell shrinkage, and nuclear condensation in a caspase-dependent fashion. Coexpression of BclxL inhibits all the apoptotic changes induced by tBID. Our results indicate that BID is a mediator of mitochondrial damage induced by Casp8.

Menadione reduced doxorubicin resistance in Ehrlich ascites carcinoma cells in vitro.

AIM: To study the effect of menadione (Men) reducing doxorubicin (Dox) resistance in Ehrlich ascites carcinoma (EAC) cells resistant to Dox (EAC/Dox cells). METHODS: Glutathione (GSH) content and membrane fluidity were measured by fluorometric assay and fluorescence depolarization assay, respectively. Glutathione S-transferase (GST) activity was measured with 1-chloro-2,4-dinitrobenzene as the substrate. Cell viability was determined by 3-(4, 5-dimethylthiazol)-2, 5-diphenyltetrazolium bromide assay. RESULTS: GSH content, GST activity, and membrane fluidity in EAC/Dox cells were higher than those in EAC cells (P < 0.01). The IC50 (95% confidence limits) for Dox on EAC/Dox cell was 22.3 (15.8-28.8) mg.L-1. Relative resistance of Dox in EAC/Dox cells was 42-fold. Pretreatment of EAC/Dox cells with Men 5 or 10 mg.L-1 decreased intracellular GSH content (P < 0.01). Men 1 mg.L-1 had no obvious effect on GSH content in EAC/Dox cells (P > 0.05), but decreased the elevated membrane fluidity efficiently (P < 0.05). Men had no obvious effect on GST activity in EAC/Dox cells (P > 0.05). IC50 of Dox was reduced to 9.6 (7.8-11.3), 6.0 (2.8-9.2), or 5.3 (3.9-6.7) mg.L-1 in EAC/Dox cells pretreated with Men 1, 5, or 10 mg.L-1. CONCLUSION: Men reduced Dox resistance effectively due in part to its depletion of GSH content in EAC/Dox cells.

Effect of phosphomonoesters, phosphodiesters, and phosphocreatine on glutamate uptake by synaptic vesicles.

L-Glutamate, a major excitatory amino acid, plays an important role in learning and memory. L-Glutamate uptake into synaptic vesicles is an ATP-dependent process. Exposure of neurons to high, sustained extracellular concentrations of glutamate results in excitotoxicity. Elevated levels of phosphomonoesters (PMEs), phosphodiesters (PDEs), and phosphocreatine (PCr) have been reported in Alzheimer disease (AD). In this article, the effects of selected PMEs, PDEs, and PCr on vesicular L-[3H]glutamate uptake into isolated bovine synaptic vesicles are investigated. D-myo-Inositol-1-monophosphate (I1P), D-myo-inositol-2-monophosphate (I2P), sn-glycero-3-phosphate, (alpha-GP) and PCr significantly stimulated L-[3H]glutamate uptake into synaptic vesicles. Phosphoethanolamine (PE), phosphocholine (PC), L-phosphoserine (L-PS) sn-glycero-3-phosphocholine (GPC), and sn-glycero-3-phosphoethanolamine (GPE) had little or no effect on vesicular L-glutamate uptake. These observations suggested that the vesicular uptake of glutamate can be regulated by endogenous PMEs and PCr. The mechanism of activation by I1P, I2P, and alpha-GP appears to be stimulation of Mg(2+)-ATPase activity. These effects on vesicular glutamate uptake may be important in diseases in which the levels of these metabolites are altered, as they are in AD.