RSSChemokine CCL2 enhances survival and invasiveness of endometrial stromal cells in an autocrine manner by activating Akt and MAPK/Erk1/2 signal pathway.
Source
Laboratory for Reproductive Immunology, Hospital and Institute of Obstetrics & Gynecology, Fudan University Shanghai Medical College, Shanghai, People's Republic of China.
Abstract
OBJECTIVE:
To clarify the role and mechanism of CCL2 in regulating the biological functions of endometrial stromal cells (ESCs).
DESIGN:
The CCL2 effect on the viability, proliferation, and invasion in the eutopic ESCs from endometriosis.
SETTING:
Research laboratories.
PATIENT(S):
Patients with endometriosis aged 23-47 years.
INTERVENTION(S):
None.
MAIN OUTCOME MEASURE(S):
Signal transduction and downstream molecules from CCR2.
RESULT(S):
We have found that the secretion of CCL2 by the eutopic ESCs from endometriosis is higher than that of healthy ESCs without endometriosis. The CCL2 can enhance the viability, proliferation, and invasion of ESCs in a dosage and time-dependent manner. Anti-CCL2 neutralizing antibody and CCR2 antagonist can completely abolish the increase in viability, proliferation, and invasiveness of ESCs induced by CCL2. The CCL2 can increase the expression ofproliferating cell nuclear antigen, survivin, and matrix metalloproteinase 2, and decrease the expression of tissue inhibitor of metalloproteinase 1 and 2, and promote the viability, proliferation and invasiveness of ESCs by activating Akt and MAPK/Erk1/2 signal pathway, but not p38 and JNK signal pathway.
CONCLUSION(S):
CCL2 might play an important role in regulating the functions of ESCs through Akt and MAPK/Erk1/2 signal pathway, and overexpression of CCL2 in ESCs and peritoneal fluid (PF) would lead to onset and development of endometriosis.
Copyright © 2012 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.
Fin reduction is a novel and unexpected teratogenic effect of amikacin-treated zebrafish embryos.
Source
Institute of Medical Sciences, Buddhist Tzu Chi University , Hualien , Taiwan.
Abstract
We used zebrafish as a model to assess amikacin-induced embryotoxicity. We exposed zebrafish embryos to amikacin, using different amikacin doses (0-10 ppm), durations (12-48 h), and onsets (0, 24, 48 hpf). Amikacin-induced embryonic toxicity and reduced survival rate were found dependent on the exposure dose, duration and onset. Based on immunostaining with neuron-specific antibodies, amikacin reduced the number and size of zebrafish neuromasts. In addition, Amikacin caused pelvic, dorsal and anal fin defects in dose-dependent and duration-dependent manners.Proliferating cell nuclear antigen immunostaining revealed that amikacin-induced fin defects were not due to reduction ofproliferating mesenchymal cells. TUNEL assay demonstrated that amikacin-induced fin defects might not associate with apoptosis. Therefore, further investigations are required to elucidate if other cell death pathways are involved in amikacin-induced fin defects.
Depletion of B2 but Not B1a B Cells in BAFF Receptor-Deficient ApoE Mice Attenuates Atherosclerosis by Potently Ameliorating Arterial Inflammation.
Source
Vascular Biology and Atherosclerosis Laboratory, Baker IDI Heart and Diabetes Institute, Victoria, Australia.
Abstract
We have recently identified conventional B2 cells as atherogenic and B1a cells as atheroprotective in hypercholesterolemic ApoE(-/-) mice. Here, we examined the development of atherosclerosis in BAFF-R deficient ApoE(-/-) mice because B2 cells but not B1a cells are selectively depleted in BAFF-R deficient mice. We fed BAFF-R(-/-) ApoE(-/-) (BaffR.ApoE DKO) and BAFF-R(+/+)ApoE(-/-) (ApoE KO) mice a high fat diet (HFD) for 8-weeks. B2 cells were significantly reduced by 82%, 81%, 94%, 72% in blood, peritoneal fluid, spleen and peripheral lymph nodes respectively; while B1a cells and non-B lymphocytes were unaffected. Aortic atherosclerotic lesions assessed by oil red-O stained-lipid accumulation and CD68+ macrophage accumulation were decreased by 44% and 50% respectively. B cells were absent in atherosclerotic lesions of BaffR.ApoE DKO mice as were IgG1 and IgG2a immunoglobulinsproduced by B2 cells, despite low but measurable numbers of B2 cells and IgG1 and IgG2a immunoglobulin concentrations in plasma. Plasma IgM and IgM deposits in atherosclerotic lesions were also reduced. BAFF-R deficiency in ApoE(-/-) mice was also associated with a reduced expression of VCAM-1 and fewer macrophages, dendritic cells, CD4+ and CD8+ T cell infiltrates and PCNA+ cells in lesions. The expression of proinflammatory cytokines, TNF-α, IL1-β and proinflammatory chemokine MCP-1 was also reduced. Body weight and plasma cholesterols were unaffected in BaffR.ApoE DKO mice. Our data indicate that B2 cells are important contributors to the development of atherosclerosis and that targeting the BAFF-R to specifically reduce atherogenic B2 cell numbers while preserving atheroprotective B1a cell numbers may be a potential therapeutic strategy to reduce atherosclerosis by potently reducing arterial inflammation.
Optimization of immunolocalization of cell cycle proteins in human corneal endothelial cells.
Abstract
PURPOSE:
En face observation of corneal endothelial cells (ECs) using flat-mounted whole corneas is theoretically much more informative than observation of cross-sections that show only a few cells. Nevertheless, it is not widespread for immunolocalization (IL) of proteins, probably because the endothelium, a superficial monolayer, behaves neither like a tissue in immunohistochemistry (IHC) nor like a cell culture in immunocytochemistry (ICC). In our study we optimized IL for ECs of flat-mounted human corneas to study the expression of cell cycle-related proteins.
METHODS:
We systematically screened 15 fixation and five antigen retrieval (AR) methods on 118 human fresh or stored corneas (organ culture at 31 °C), followed by conventional immunofluorescence labeling. First, in an attempt to define a universal protocol, we selected combinations able to correctly localize four proteins that are perfectly defined in ECs (zonula occludens-1 [ZO-1] and actin) or ubiquitous (heterogeneous nuclear ribonucleoprotein L [hnRNP L] and histone H3). Second, we screened protocols adapted to the revelation of 9 cell cycle proteins: Ki67, proliferating cell nuclear antigen (PCNA), minichromosome maintenance protein 2 (MCM2), cyclin D1, cyclin E, cyclin A, p16(Ink4a), p21(Cip1) and p27(Kip1). Primary antibody controls (positive controls) were performed on both epithelial cells of the same, simultaneously-stained whole corneas, and by ICC on human ECs in in vitro non-confluent cultures. Both controls are known to contain proliferating cells. IL efficiency was evaluated by two observers in a masked fashion. Correct localization at optical microscopy level in ECs was define as clear labeling with no background, homogeneous staining, agreement with previous works on ECs and/or protein functions, as well as a meaningful IL in proliferating cells of both controls.
RESULTS:
The common fixation with 4% formaldehyde (gold standard for IHC) failed to reveal 12 of the 13 proteins. In contrast, they were all revealed using either 0.5% formaldehyde at room temperature (RT) during 30 min alone or followed by AR with sodium dodecyl sulfate or trypsin, or pure methanol for 30 min at RT. Individual optimization was nevertheless often required to optimize the labeling. Ki67 was absent in both fresh and stored corneas, whereas PCNAwas found in the nucleus, and MCM2 in the cytoplasm, of all ECs. Cyclin D1 was found in the cytoplasm in a paranuclear pattern much more visible after corneal storage. Cyclin E and cyclin A were respectively nuclear and cytoplasmic, unmodified by storage. P21 was not found in ECs with three different antibodies. P16 and p27 were exclusively nuclear, unmodified by storage.
CONCLUSIONS:
IL in ECs of flat-mounted whole human corneas requires a specific sample preparation, especially to avoid overfixation with aldehydes that probably easily masks epitopes. En face observation allows easy analysis of labeling pattern within the endothelial layer and clear subcellular localization, neither of which had previously been described for PCNA, MCM2, or cyclin D1.
Cellular Apoptosis and Proliferation in the Middle and Late Intrasynovial Tendon Healing Periods.
Source
Hand Surgery Research Center, Department of Hand Surgery, Affiliated Hospital of Nantong University, Nantong, China; Department of Plastic Surgery, Rhode Island Hospital, Brown Alpert Medical School, Providence, RI; Department of Anatomy, Nantong University, Nantong, China.
Abstract
PURPOSE:
Cellular apoptosis might be an important molecular event in the middle or late healing periods of intrasynovial tendons, but this has not been studied. We aimed to investigate cellular apoptosis and corresponding cellular proliferation in the middle and late healing stages of intrasynovial tendons.
METHODS:
The flexor digitorum profundus tendons of 48 long toes (24 chickens) were completely transected within the sheath region and were repaired surgically. At days 28, 42, 56, and 84 after surgery, tendons were harvested and sectioned. In situ terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay was performed to detect apoptotic cells. The sections were stained immunofluorescently with antibodies to proliferating cell nuclear antigen to assess proliferation and to Bcl-2 (an anti-apoptotic protein). Positively stained tenocytes were counted, and their distributional differences were verified in 3-dimensional images.
RESULTS:
The repaired intrasynovial tendons exhibited generally greater apoptosis in the surface region than in the core. The differences were more remarkable in the extended region than in the junction region of the cut tendon. At the core of the junction site, apoptosis of tenocytes was pronounced at all time points, but it was less severe at the core of the extended region. The proliferating cell nuclear antigen-positive and Bcl-2-positive tenocytes decreased significantly and continually at days 28, 42, and 56, respectively; these tenocytes were at a minimum at days 56 and 84.
CONCLUSIONS:
Apoptotic changes of tenocytes are most marked in the surface region and in the junction region of the healing tendon in the middle and late healing stages. Apoptosis in the core is less dramatic compared to that in the surface in the extended tendon regions. Cellular proliferation declines drastically and is minimal at days 56 and 84.
CLINICAL RELEVANCE:
Tenocyte apoptosis in the middle and late stages might be an important event contributing to intrasynovial tendon remodeling, which affects the healing strength and formation of adhesions.
Copyright © 2011 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.
Synchronized expressions of hepatic stellate cells and their transactivation and liver regeneration during liver injury in an animal model of cholestasis.
Source
Department of Pediatric Surgery, Reproductive and Developmental Medicine, Kyushu University, Fukuoka, Japan. safira@pedsurg.med.kyushu-u.ac.jp
Abstract
BACKGROUND:
There is much known about hepatic stellate cells (HSCs) during liver injury. However, some aspects remain unclear, such as the natural expression levels of HSCs during the days to weeks after liver injury. Does liver regeneration start the same time as the injury process?
METHODS:
Fifty-four male Wistar rats aged 7 to 8 weeks, weighing 200 to 320 g each were subjected to bile duct ligation (BDL). After surgery, they were killed at different times post-BDL. Collagen deposition was analyzed, and immunohistochemical staining of α-smooth muscle actin (α-SMA), vimentin, matrix metalloproteinase-2 (MMP-2), tissue inhibitor matrix metalloproteinase-1, and proliferating cell nuclear antigen antibody (PCNA) was performed to evaluate HSCs and liver regeneration.
RESULTS:
The expression of α-SMA was seen as early as day 3 post-BDL, which started from peribiliary to perisinusoidal, and was seen throughout the whole liver sections on day 28 post-BDL. Similar expression patterns were seen in MMP-2 staining. The PCNA expression was strongest around the perisinusoidal area. These expression patterns were not observed in the sham-operated rats.
CONCLUSIONS:
The activation of HSCs showed a synchronized fibrogenic process and liver regeneration from days to weeks after liver injury. Matrix degradation was thus found to increase in accordance with chronic liver injury, which thus led to an excessive collagen deposition.
Copyright © 2011 Elsevier Inc. All rights reserved.
The importance of tumor proliferation markers in assessing lesions of the palatine tonsil.
Source
Department of ENT, University of Medicine and Pharmacy of Craiova, Romania. carmen_mogo@yahoo.com
Abstract
Oropharyngeal cancer, and especially squamous cell carcinoma, is one of the most common cancers worldwide, and its incidence is increasing, with the palatine tonsil being one of the main locations. The etiopathogenic factors, together with its location as well as the available immunohistochemical methods, make this type of cancer an accessible one in terms of diagnosis. However, it is usually diagnosed in late stages. Therefore, we tried to elucidate the causes of treatment failures and development of local recurrence. For this, we reassessed the proliferative pattern of tonsil lesions using the anti-p53, anti-PCNA and anti-Ki67 antibodies on 73 tonsil fragments collected after curative surgery on adults aged between 28 and 86 years. Following the reevaluation of the histopathological examination using markers for cellproliferation, the diagnosis was modified in 16 cases, representing about 22% of the cases take into study. By using immunohistochemical markers in the histopathological examination the diagnosis is improved, leading to a more appropriate therapeutical approach.
Crosstalk between integrin αvβ3 and estrogen receptor-α is involved in thyroid hormone-induced proliferation in human lung carcinoma cells.
Source
Ordway Signal Transduction, Albany, New York, United States of America.
Abstract
A cell surface receptor for thyroid hormone that activates extracellular regulated kinase (ERK) 1/2 has been identified on integrin αvβ3. We have examined the actions of thyroid hormone initiated at the integrin on human NCI-H522 non-smallcell lung carcinoma and NCI-H510A small cell lung cancer cells. At a physiologic total hormone concentration (10(-7) M), T(4) significantly increased proliferating cell nuclear antigen (PCNA) abundance in these cell lines, as did 3, 5, 3'-triiodo-L-thyronine (T(3)) at a supraphysiologic concentration. Neutralizing antibody to integrin αvβ3 and an integrin-binding Arg-Gly-Asp (RGD) peptide blocked thyroid hormone-induced PCNA expression. Tetraiodothyroacetic acid (tetrac) lacks thyroid hormone function but inhibits binding of T(4) and T(3) to the integrin receptor; tetrac eliminated thyroid hormone-induced lung cancer cell proliferation and ERK1/2 activation. In these estrogen receptor-α (ERα)-positive lung cancer cells, thyroid hormone (T(4)>T(3)) caused phosphorylation of ERα; the specific ERα antagonist ICI 182,780 blocked T(4)-induced, but not T(3)-induced ERK1/2 activation, as well as ERα phosphorylation, proliferating-cell nuclear antigen (PCNA) expression and hormone-dependent thymidine uptake by tumor cells. Thus, in ERα-positive human lung cancer cells, the proliferative action of thyroid hormone initiated at the plasma membrane is at least in part mediated by ERα. In summary, thyroid hormone may be one of several endogenous factors capable of supporting proliferation of lung cancer cells. Activity as an inhibitor of lung cancer cell proliferation induced at the integrin receptor makes tetrac a novel anti-proliferative agent.
Trophoblast-derived chemokine CXCL12 promotes CXCR4 expression and invasion of human first-trimester decidual stromal cells.
Source
Reproductive Medicine Center , Zhongnan Hospital of Wuhan University, Wuhan 430071, People's Republic of China.
Abstract
BACKGROUND The aim of this study was to investigate the role of the chemokine (C-X-C motif) ligand 12/chemokine (C-X-C motif) receptor 4 (CXCL12/CXCR4) axis on the crosstalk between human first-trimester trophoblast cells (TCs) and decidual stromal cells (DSCs), to contribute to a better understanding of the molecular mechanisms on the interaction between the mother and embryo during pregnancy. METHODS CXCR4 on human first-trimester DSC membranes was detected by flow cytometry. The effects of exogenous CXCL12 or TC-conditioned medium (TCM) on proliferation and invasion of DSCs were examined by measuring proliferating cell nuclear antigen (PCNA) and an invasion assay, respectively. Finally, a co-culture model was established to investigate the effect of CXCL12 secreted from TCs on motility of DSCs. RESULTS The mean (±SEM) percentage of DSCs positive for CXCR4 was 32.32 ± 7.18%. Human recombinant CXCL12 induced an increase in CXCR4 levels on DSCs via binding to CXCR4 (P < 0.01) but had no effect on the PCNA expression of DSCs. Moreover, both exogenous CXCL12 and TCM reinforced the invasive ability of DSCs via CXCR4 ligation. A co-culture model further confirmed that the enhanced invasiveness of DSCs in co-culture with TCs was inhibited by anti-CXCR4 or anti-CXCL12 neutralizing antibody (both P< 0.01). CONCLUSIONS Human first-trimester DSCs express membrane CXCR4 and TC-derived CXCL12 promotes CXCR4 expression and invasion of DSCs via ligation with CXCR4. Our data highlight the role of CXCL12/CXCR4 axis on the co-operation between TCs and DSCs during human first-trimester pregnancy.
Adipocytes enhance the proliferation of human leiomyoma cells via TNF-α proinflammatory cytokine.
Source
Department of Obstetrics and Gynecology, Center for Women's Health Research, Meharry Medical College, Nashville, TN 37208, USA.
Abstract
OBJECTIVE:
Obesity is a well-documented risk factor for uterine leiomyoma with a major impact on women health and health care system of the nation. Obesity is associated with increased secretion of adipokines that significantly influence growth and proliferation of tumor stroma and malignant cells. Adipokines, such as tumor necrosis factor α (TNF-α), are produced in the adipose tissue with concomitant expression in other organs and tissues. Increased and sustained cytokine production is associated with alterations in cell growth and differentiation. We, therefore, explored the influence of human adipocytes (SW872 cells)-mediated biological humoral factors on human uterine leiomyoma (HuLM) cells.
METHODS:
We measured cell proliferation and expression of cell-proliferating proteins (proliferating cell nuclear antigen[PCNA], cyclin D1, and B-cell lymphoma 2 [BCL-2]) in human leiomyoma cells cocultured with SW872 cells. SW872-conditioned media was neutralized for TNF-α and proliferation of HuLM cells was observed along with antiapoptotic marker, BCL-2, using Western immunoblot.
RESULTS:
We found that both SW872-conditioned media and coculture with SW872 cells increased HuLM cellproliferation significantly (P < .05). We determined that this effect was associated with the upregulation of specific markers for proliferation, such as PCNA, cyclin D1, and BCL-2 (P < .05). Furthermore, the addition of neutralizingantibodies, anti-TNF-α, to SW872-conditioned media reversed the proliferation of leiomyoma cells and induced apoptosis as indicated by the reduced expression of antiapoptotic marker BCL-2.
CONCLUSIONS:
SW872 cells secrete TNF-α, which is associated with a proliferative gene profile in HuLM cells and may play a role in initiation and/or progression of uterine leiomyoma.
Hepatic arterial infusion of bevacizumab in combination with oxaliplatin reduces tumor growth in a rat model of colorectal liver metastases.
Source
Department of General, Visceral, Vascular and Pediatric Surgery, University of Saarland, 66421, Homburg/Saar, Germany, jens.sperling@uniklinikum-saarland.de.
Abstract
Unresectable colorectal liver metastases are commonly treated with systemic chemotherapy (SCT). Clinical studies on the effect of additional systemic application of bevacizumab (BE), a monoclonal antibody directed against vascular endothelial growth factor, to SCT showed a slight increase of patient survival. Herein, we studied in a rat model of colorectal liver metastasis whether a locoregional application of oxaliplatin (OX) and BE via hepatic arterial infusion (HAI) is more effective to inhibit metastatic growth compared to systemic drug application. Ten days after implantation of CC531 colorectal cancer cells into the left liver lobe of WAG/Rij rats, animals underwent either HAI or systemic intravenous application of BE (5 mg/kg body weight), OX (85 mg/m(2) body surface) or a combination of both. Sham-treated animals received saline and served as controls. Tumor volume was measured at days 10 and 13 using three dimensional ultrasound. At day 13 tumor tissue was analyzed histologically and immunohistochemically. Systemic application of OX, BE or their combination did not affect tumor volume when compared to controls. In contrast, HAI of BE and particularly the combination of BE and OX significantly reduced tumor volume. In the tumor tissue this was associated with a decrease of vascularization and cell proliferation as well as an increase of cell apoptosis, as indicated by a decreased number of PECAM-1- and PCNA-positive cells and an increased number of cleaved caspase-3-positive cells. Locoregional administration of BE, particularly in combination with OX, enhances the inhibitory effect on hepatic metastatic growth compared to systemic application of the drugs.
[Effect of trimegestone on mammary gland of castrated rats].
Source
FEPAR – Curitiba(PR), Brasil.
Abstract
PURPOSE:
To evaluate the efect of trimegestone on the histological changes of the mammary tissue of castrated rats.
METHODS:
Forty-five virgin female Wistar rats were used after oophorectomy. Sixty days after surgery, with hypoestrogenisms confirmed, the experimental rats were randomly assigned to three groups of 15 animals each, when then the specific treatment for each group was started. The control group (C) and experimental groups 1 and 2 respectively received 0.9% saline solution, 17-beta-estradiol and 17-beta-estradiol in combination with trimegestone for 60 consecutive days. After the end of treatment , the inguinal mammary glands were removed, stained with hematoxylin and eosin (HE) for morphometry and examined by immunohistochemistry for the quantification of anti-PCNA antibody in the mammary tissue, followed by euthanasia. The morphometric parameters evaluated were: epithelium cell-proliferation, secretor activity and mammary stroma changes. There were nine deaths during the experiment. The variables were submitted to statistical analysis adopting the 0.05 level of significance.
RESULTS:
Histological changes were observed in 16/36 rats, mild epithelial hyperplasia in 13/36, moderate epithelial hyperplasia in 3/36, with no cases of severe epithelial hyperplasia. Stromal fibrosis was found in 10/36 and secretory activity in 5/36 rats. All morphometric variables were significant in the estrogen group compared to control (p=0.0361), although there were no difference between the group receiving combined treatment and the controls (p=0.405). The immunohistochemical analysis showed no difference between groups.
CONCLUSIONS:
The hormones administered to castrated rats, i.e., 17 beta-estradiol alone or in combination with trimegestone, increased the proliferation of breast cells, but this effect appeared to be lower in the combined treatment, the same occurring regarding fibrosis of the mammary stroma.
Serum autoantibody biomarkers for age-related macular degeneration and possible regulators of neovascularization.
Source
Division of Allergy and Immunology, Department of Pediatrics, Cincinnati Children's Hospital, Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH, USA; Department of Ophthalmology, Emory University School of Medicine and Emory Eye Center, Dobbs Ocular Immunology Laboratories, Atlanta, GA, USA.
Abstract
Age-related macular degeneration (AMD) is the leading cause of irreversible blindness in industrial counties. Its pathogenesis is at least partially mediated by immunological factors, including a possible autoimmune response. To date, only a few antibodies have been identified in sera from patients with AMD. In order to reveal an autoantibody profile for AMD and identify biomarkers for progression of this disease, we have performed an antigen microarray analysis of serum samples from patients with AMD and healthy controls. Sera from the AMD groups contained high levels of IgG and IgM autoantibodies to some systemic antigens when compared to the normal group. Targeted antigens included cyclic nucleotide phosphodiesterase, phosphatidylserine (PS) and proliferating cell nuclear antigen. The IgG/IgM ratio forantibodies to PS was notably elevated in the AMD group compared to the normal group, and this ratio correlated best with the stage of AMD patients with an anti-PS ratio greater than the cut-off value had a 44-fold risk for advanced AMD with choroidal neovascularization. PS immunoreactivity was also elevated in AMD retina. Moreover, IgG autoantibodies purified from sera of AMD patients induced more tube formation on choroidal-retinal endothelial cells compared to those of healthy donors. Hence, sera from patients with AMD contain specific autoantibodies which may be used as biomarkers for AMD, and the IgG/M ratio for autoantibodies to PS might allow better monitoring of AMD progression.
Copyright © 2011 Elsevier Inc. All rights reserved.
First description of an olfactory neuroblastoma in goldfish Carassius auratus: a case report.
Source
Cátedra de Histología y Embriología, Facultad de Ciencias Veterinarias, Universidad Nacional de Rosario, S2170HGJ Casilda, Argentina. fviglian@fveter.unr.edu.ar
Abstract
An external pinkish growing mass that emerged from the right nostril of an adult goldfish Carassius auratus L. was evaluated by means of light microscopy and immunohistochemistry. The neoplasm presented a well-developed fibrovascular stroma associated with solid cell nests and a large number of Flexner-Wintersteiner rosettes. Myelinated fibres were observed around them. Neoplastic cells showed a prominent degree of nuclear atypia and low mitotic activity. The latter was in agreement with the low reactivity of tumour cells to anti-proliferating cell nuclear antigenantibody. Immunohistochemistry also revealed anti-neuronal nitric oxide synthase, anti-S100 protein, antineuropeptide Y, and anti-cytokeratin immunoreactivity in tumour cells as well as in normal olfactory epithelium of goldfish control sections. Histopathological and immunohistochemical findings strongly suggest a diagnosis of an olfactory neuroblastoma (ONB). To our knowledge this is the first description of ONB in goldfish.
- PMID:
- 21991666
- [PubMed - indexed for MEDLINE]
Silencing of p130cas in ovarian carcinoma: a novel mechanism for tumor celldeath.
Source
Department of Gynecologic Oncology, University of Texas M. D. Anderson Cancer Center, Houston, TX 77230-1439, USA.
Abstract
BACKGROUND:
We investigated the clinical and biological significance of p130cas, an important cell signaling molecule, in ovarian carcinoma.
METHODS:
Expression of p130cas in ovarian tumors, as assessed by immunohistochemistry, was associated with tumor characteristics and patient survival. The effects of p130cas gene silencing with small interfering RNAs incorporated into neutral nanoliposomes (siRNA-DOPC), alone and in combination with docetaxel, on in vivo tumor growth and on tumor cell proliferation (proliferating cell nuclear antigen) and apoptosis (terminal deoxynucleotidyl transferase dUTP nick-end labeling) were examined in mice bearing orthotopic taxane-sensitive (HeyA8 and SKOV3ip1) or taxane-resistant (HeyA8-MDR) ovarian tumors (n = 10 per group). To determine the specific mechanisms by which p130cas gene silencing abrogates tumor growth, we measured cell viability (MTT assay), apoptosis (fluorescence-activated cell sorting), autophagy (immunoblotting, fluorescence, and transmission electron microscopy), and cellsignaling (immunoblotting) in vitro. All statistical tests were two-sided.
RESULTS:
Of 91 ovarian cancer specimens, 70 (76%) had high p130cas expression; and 21 (24%) had low p130cas expression. High p130cas expression was associated with advanced tumor stage (P < .001) and higher residual disease (>1 cm) following primary cytoreduction surgery (P = .007) and inversely associated with overall survival and progression-free survival (median overall survival: high p130cas expression vs low expression, 2.14 vs 9.1 years, difference = 6.96 years, 95% confidence interval = 1.69 to 9.48 years, P < .001; median progression-free survival: high p130cas expression vs low expression, 1.04 vs 2.13 years, difference = 1.09 years, 95% confidence interval = 0.47 to 2.60 years, P = .01). In mice bearing orthotopically implanted HeyA8 or SKOV3ip1 ovarian tumors, treatment with p130cas siRNA-DOPC in combination with docetaxel chemotherapy resulted in the greatest reduction in tumor growth compared with control siRNA therapy (92%-95% reduction in tumor growth; P < .001 for all). Compared with control siRNA therapy, p130cas siRNA-DOPC reduced SKOV3ip1 cell proliferation (31% reduction, P < .001) and increased apoptosis (143% increase, P < .001) in vivo. Increased tumor cell apoptosis may have persisted despite pan-caspase inhibition by the induction of autophagy and related signaling pathways.
CONCLUSIONS:
Increased p130cas expression is associated with poor clinical outcome in human ovarian carcinoma, and p130cas gene silencing decreases tumor growth through stimulation of apoptotic and autophagic cell death.
- PMID:
- 21957230
- [PubMed - indexed for MEDLINE]
- PMCID: PMC3206039
- [Available on 2012/11/2]
Increased levels of the cell cycle inhibitor protein, dacapo, accompany 20-hydroxyecdysone-induced G1 arrest in a mosquito cell line.
Source
Department of Entomology, University of Minnesota, St. Paul, USA.
Abstract
When treated with the steroid hormone 20-hydroxyecdysone (20E), C7-10 cells from the mosquito, Aedes albopictus, arrest in the G1 phase of the cell cycle. To explore whether 20E-mediated cell cycle arrest proceeds through increased levels of cell cycle inhibitor (CKI) proteins, we cloned the Ae. albopictus homolog of dacapo, the single member of the Cip/Kip family of CKI proteins known from Drosophila melanogaster. The Ae. albopictus dacapo cDNA encoded a 261-amino acid homolog of the Aedes aegypti protein XP_001651102.1, which is encoded by an ∼23 kb gene containing three exons. Like dacapo from D. melanogaster, the ∼27 kDa protein from Aedes and Culex mosquitoes contained several S/TXXE/D motifs corresponding to potential protein kinase CK2 phosphorylation sites, and a binding site forproliferating cell nuclear antigen (PCNA). When extracts from cells treated with 20E were analyzed by western blotting, using a primary antibody to synthetic peptides from the mosquito dacapo protein, up-regulation of an ∼27 kDa protein was observed within 24 h, and the abundance of the protein further increased by 48 h after hormone treatment. This is the first investigation of a cell cycle inhibitory protein in mosquitoes. The results reinforce growing evidence that 20E affects expression of proteins that regulate cell cycle progression.
© 2011 Wiley-Liss, Inc.
PCNA ubiquitination-independent activation of polymerase η during somatic hypermutation and DNA damage tolerance.
Source
Division of Immunology, The Netherlands Cancer Institute, 1066 CX Amsterdam, The Netherlands.
Abstract
The generation of high affinity antibodies in B cells critically depends on translesion synthesis (TLS) polymerases that introduce mutations into immunoglobulin genes during somatic hypermutation (SHM). The majority of mutations at A/T base pairs during SHM require ubiquitination of PCNA at lysine 164 (PCNA-Ub), which activates TLS polymerases. By comparing the mutation spectra in B cells of WT, TLS polymerase η (Polη)-deficient, PCNA(K164R)-mutant, andPCNA(K164R);Polη double-mutant mice, we now find that most PCNA-Ub-independent A/T mutagenesis during SHM is mediated by Polη. In addition, upon exposure to various DNA damaging agents, PCNA(K164R) mutant cells display strongly impaired recruitment of TLS polymerases, reduced daughter strand maturation and hypersensitivity. Interestingly, compared to the single mutants, PCNA(K164R);Polη double-mutant cells are dramatically delayed in S phase progression and far more prone to cell death following UV exposure. Taken together, these data support the existence of PCNA ubiquitination-dependent and -independent activation pathways of Polη during SHM and DNA damage tolerance.
Copyright © 2011 Elsevier B.V. All rights reserved.
A case of xanthoma in a Saanen goat.
Source
Department of Pathology, Faculty of Veterinary Medicine, University of Mehmet Akif Ersoy, Ortulu Yerleskesi, Burdur, Turkey.
Abstract
This report describes a case of a subcutaneous xanthoma of the sacral region in a 2-year-old female Saanen goat. The tan-coloured mass was 8.5 cm × 4.0 cm × 0.5 cm in size. Yellow-white areas were present across the cut surface. Histopathologically, the mass was composed of foamy macrophages, numerous giant cells, abundant lipid material and cholesterol clefts. The structure consisted of lobular areas surrounded by a stroma. Tissue sections were negative for bacteria, fungi and mycobacteria. Frozen tissue from the mass stained positively with Oil Red O, confirming lipid accumulation in both the extracellular spaces and the large foamy macrophages. Immunohistochemically, the mass was positive for vimentin, proliferating cell nuclear antigen and CD68, but negative for smooth muscle actin, glial fibrillary acidic protein and S100 protein antibodies. As the animal was presented dead, it was not possible to analyse blood lipid levels. To the authors' knowledge, this is the first report of a xanthoma in a goat.
© 2011 The Authors. Veterinary Dermatology © 2011 ESVD and ACVD.
- PMID:
- 21883545
- [PubMed - as supplied by publisher]
A quantitative analysis of transcriptionally active syncytiotrophoblast nuclei across human gestation.
Source
Department Physiology, Development and Neuroscience, University of Cambridge, Cambridge, UK.
Abstract
The syncytiotrophoblast (STB) epithelial covering of the human placenta is a unique terminally differentiated, multi-nucleated syncytium. No mitotic bodies are observed in the STB, which is sustained by continuous fusion of underlying cytotrophoblast cells (CTB). As a result, STB nuclei are of different ages. Morphologically, they display varying degrees of chromatin compaction, suggesting progressive maturational changes. Until recently, it was thought that STB nuclei were transcriptionally inactive, with all the mRNAs required by the syncytium being incorporated upon fusion of CTB. However, recent research has shown the presence of the active form of RNA polymerase II (RNA Pol II) in some STB nuclei. In this study, we confirm the presence of transcriptional activity in STB nuclei by demonstrating immunoreactivity for a transcription factor and an RNA polymerase I (RNA Pol I) co-factor, phospho-cAMP response element-binding protein and phospho-upstream binding factor, respectively. We also show, through immunoco-localisation studies, that a proportion of STB nuclei are both RNA Pol I and II transcriptionally active. Finally, we quantify the numerical densities of nuclei immunopositive and immunonegative for RNA Pol II in the STB of normal placentas of 11-39 weeks gestational age using an unbiased stereological counting tool, the physical disector. These data were combined with estimates of the volume of trophoblast to calculate total numbers of both types of nuclei at each gestational age. We found no correlation between gestational age and the numerical density of RNA Pol II-positive nuclei in the villous trophoblast (r = 0.39, P > 0.05). As the number of STB nuclei increases exponentially during gestation, we conclude that the number of transcriptionally active nuclei increases in proportion to trophoblast volume. The ratio of active to inactive nuclei remains constant at 3.9:1. These findings confirm that the majority of STB nuclei have intrinsic transcriptional activity, and that the STB is not dependent on CTB fusion for the provision of transcripts.
© 2011 The Authors. Journal of Anatomy © 2011 Anatomical Society of Great Britain and Ireland.
Characterization of Leishmania donovani MCM4: expression patterns and interaction with PCNA.
Source
Department of Microbiology, University of Delhi South Campus, New Delhi, India.
Abstract
Events leading to origin firing and fork elongation in eukaryotes involve several proteins which are mostly conserved across the various eukaryotic species. Nuclear DNA replication in trypanosomatids has thus far remained a largely uninvestigated area. While several eukaryotic replication protein orthologs have been annotated, many are missing, suggesting that novel replication mechanisms may apply in this group of organisms. Here, we characterize the expression of Leishmania donovani MCM4, and find that while it broadly resembles other eukaryotes, noteworthy differences exist. MCM4 is constitutively nuclear, signifying that, unlike what is seen in S.cerevisiae, varying subcellular localization of MCM4 is not a mode of replication regulation in Leishmania. Overexpression of MCM4 in Leishmania promastigotes causes progress through S phase faster than usual, implicating a role for MCM4 in the modulation of cellcycle progression. We find for the first time in eukaryotes, an interaction between any of the proteins of the MCM2-7 (MCM4) and PCNA. MCM4 colocalizes with PCNA in S phase cells, in keeping with the MCM2-7 complex being involved not only in replication initiation, but fork elongation as well. Analysis of a LdMCM4 mutant indicates that MCM4 interacts with PCNA via the PIP box motif of MCM4--perhaps as an integral component of the MCM2-7 complex, although we have no direct evidence that MCM4 harboring a PIP box mutation can still functionally associate with the other members of the MCM2-7 complex- and the PIP box motif is important for cell survival and viability. In Leishmania, MCM4 may possibly help in recruiting PCNA to chromatin, a role assigned to MCM10 in other eukaryotes.
No comments:
Post a Comment