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  • Complement and alcoholic liver disease: role of C1q in the pathogenesis of ethanol-induced liver injury in mice. 20416309

    BACKGROUND & AIMS: Complement is involved in the development of alcoholic liver disease in mice; however, the mechanisms for complement activation during ethanol exposure have not been identified. C1q, the recognition subunit of the first complement component, binds to apoptotic cells, thereby activating the classical complement pathway. Because ethanol exposure increases hepatocellular apoptosis, we hypothesized that ethanol-induced apoptosis would lead to activation of complement via the classical pathway.
    Document Type:
    Reference
    Product Catalog Number:
    Multiple
    Product Catalog Name:
    Multiple
  • Inhibitory Effect of intravitreal Injection of Bevacizumab on Nerve Growth Factor. 22040304

    Purpose: To investigate the inhibitory effect of intravitreal injection of bevacizumab on the expression of nerve growth factor (NGF) in rabbit retina. Methods: The right eyes of 40 New Zealand white rabbits were injected with 1.25 mg (0.05 cc) bevacizumab three times monthly; as controls, the left eyes received sham injections. Apoptosis in retinal cells was evaluated by immunohistochemical staining for caspase-3, and by in situ terminal deoxynucleotidyl transferase-mediated biotin-deoxyuridine triphosphate nick-end labeling (TUNEL) of DNA fragments. NGF and vascular endothelial growth factor (VEGF) proteins in rabbit retinas were measured quantitatively (Enzyme linked immunosorbent assay (ELISA)) and qualitatively (immunohistochemical staining) 1 and 4 months after injection. NGF and VEGF messenger RNAs in rabbit retinas were evaluated by real-time polymerase chain reaction (RT-PCR). Results: As shown by the TUNEL assay and caspase-3 immunostaining, the bevacizumab-injected group had significantly more apoptotic activity than did the control group. Levels of retinal NGF and VEGF proteins in the bevacizumab group were lower than those in the control group (p < 0.05). Immunohistochemical staining of NGF and VEGF was weaker in the bevacizumab group than in the control group. NGF and VEGF mRNA levels in the bevacizumab group were lower than those of the control group (p < 0.05). Conclusions: Findings of the present study suggest that apoptosis in retinal cells after intravitreal bevacizumab injection is increased by down-regulated NGF, caused by VEGF inhibition in rabbits.
    Document Type:
    Reference
    Product Catalog Number:
    Multiple
    Product Catalog Name:
    Multiple
  • An imbalance in Akt/mTOR is involved in the apoptotic and acantholytic processes in a mouse model of pemphigus vulgaris. 19552768

    Pemphigus vulgaris (PV) is an autoimmune blistering disease characterized by the presence of IgG autoantibodies against Dsg3. Our aim was to investigate the molecular events implicated in the development and localization of apoptosis and acantholysis in PV. We used a passive transfer mouse model together with immunohistochemical (IHC) techniques and the TUNEL assay, with quantification analysis in the basal layer of the epidermis. The activated signalling molecules analysed and apoptotic cells detected showed an identical localization. Herein, we found for the first time in vivo an increased expression of activated HER receptor isoforms in the basal layer in PV lesions. Besides, we observed the almost total lack of activated Akt compared with a higher level of activated mTOR within the basal cells of the epidermis. Our observations strongly support that the restriction of acantholysis to the basal layer may be due, at least in part, to the selective and increased presence of activated HER receptor isoforms in these cells. After phosphorylation of HER receptor isoforms, intracellular signalling pathways are activated in the basal layer. In addition, the imbalance in Akt/mTOR that takes place in the basal cells may provide intracellular signals necessary for the development of apoptosis and acantholysis.
    Document Type:
    Reference
    Product Catalog Number:
    S7101
    Product Catalog Name:
    ApopTag® Plus Peroxidase In Situ Apoptosis Kit - (ApopTag® Plus Peroxidase In Situ Apoptosis Kit)
  • Transplantation of genetically engineered cardiac fibroblasts producing recombinant human erythropoietin to repair the infarcted myocardium. 19014419

    ABSTRACT: BACKGROUND: Erythropoietin possesses cellular protection properties. The aim of the present study was to test the hypothesis that in situ expression of recombinant human erythropoietin (rhEPO) would improve tissue repair in rat after myocardial infarction (MI). METHODS AND RESULTS: RhEPO-producing cardiac fibroblasts were generated ex vivo by transduction with retroviral vector. The anti-apoptotic effect of rhEPO-producing fibroblasts was evaluated by co-culture with rat neonatal cardiomyocytes exposed to H2O2-induced oxidative stress. Annexin V/PI assay and DAPI staining showed that compared with control, rhEPO forced expression markedly attenuated apoptosis and improved survival of cultured cardiomyocytes. To test the effect of rhEPO on the infarcted myocardium, Sprague-Dawley rats were subjected to permanent coronary artery occlusion, and rhEPO-producing fibroblasts, non-transduced fibroblasts, or saline, were injected into the scar tissue seven days after infarction. One month later, immunostaining identified rhEPO expression in the implanted engineered cells but not in controls. Compared with non-transduced fibroblasts or saline injection, implanted rhEPO-producing fibroblasts promoted vascularization in the scar, and prevented cell apoptosis. By two-dimensional echocardiography and postmortem morphometry, transplanted EPO-engineered fibroblasts did not prevent left ventricular (LV) dysfunction and adverse LV remodeling 5 and 9 weeks after MI. CONCLUSION: In situ expression of rhEPO enhances vascularization and reduces cell apoptosis in the infarcted myocardium. However, local EPO therapy is insufficient for functional improvement after MI in rat.
    Document Type:
    Reference
    Product Catalog Number:
    S7101
    Product Catalog Name:
    ApopTag® Plus Peroxidase In Situ Apoptosis Kit - (ApopTag® Plus Peroxidase In Situ Apoptosis Kit)
  • Stem cell apoptosis in HIV-1 alopecia. 17026518

    BACKGROUND: Diffuse alopecia occurs in almost 7% of HIV-1-infected patients. Telogen effluvium is the main pathogenic mechanism involved. Apoptotic keratinocytes in the outer root sheath at bulge level was described as the most characteristic histopathologic finding of this kind of hair loss. METHODS: A case-control study was conducted to investigate the occurrence of apoptosis of follicular stem cells at the bulge in diffuse alopecia of HIV-1 infection. We applied a double-staining procedure to transverse scalp sections from 15 HIV-1-infected patients and 12 controls, with the monoclonal antibody anticytokeratin 19 as stem cell marker and TUNEL technique to identify apoptosis. RESULTS: Eighty percent of cases and 25% of controls presented at least one double-stained follicle. The proportion of positive follicles per section was 48% (+/-7%) for cases and 26% (+/-13%) for controls. CONCLUSION: Our study demonstrated that diffuse alopecia related to HIV-1 infection represents a hair cycle disturbance and that part of the follicular stem cell population become apoptotic in a higher proportion than normal subjects. We found no cytotoxic folliculitis. Owing to its cell-cycle interaction and caspase-induction capacities, we propose HIV-1 viral protein R as a possible follicular stem cell apoptosis inductor.
    Document Type:
    Reference
    Product Catalog Number:
    S7101
    Product Catalog Name:
    ApopTag® Plus Peroxidase In Situ Apoptosis Kit - (ApopTag® Plus Peroxidase In Situ Apoptosis Kit)
  • SMARCAL1 deficiency predisposes to non-Hodgkin lymphoma and hypersensitivity to genotoxic agents in vivo. 22888040

    Schimke immuno-osseous dysplasia (SIOD) is a multisystemic disorder with prominent skeletal, renal, immunological, and ectodermal abnormalities. It is caused by mutations of SMARCAL1 (SWI/SNF-related, matrix-associated, actin-dependent regulator of chromatin, subfamily a-like 1), which encodes a DNA stress response protein. To determine the relationship of this function to the SIOD phenotype, we profiled the cancer prevalence in SIOD and assessed if defects of nucleotide excision repair (NER) and nonhomologous end joining (NHEJ), respectively, explained the ectodermal and immunological features of SIOD. Finally, we determined if Smarcal1(del/del) mice had hypersensitivity to irinotecan (CPT-11), etoposide, and hydroxyurea (HU) and whether exposure to these agents induced features of SIOD. Among 71 SIOD patients, three had non-Hodgkin lymphoma (NHL) and one had osteosarcoma. We did not find evidence of defective NER or NHEJ; however, Smarcal1-deficient mice were hypersensitive to several genotoxic agents. Also, CPT-11, etoposide, and HU caused decreased growth and loss of growth plate chondrocytes. These data, which identify an increased prevalence of NHL in SIOD and confirm hypersensitivity to DNA damaging agents in vivo, provide guidance for the management of SIOD patients. © 2012 Wiley Periodicals, Inc.
    Document Type:
    Reference
    Product Catalog Number:
    S7101
    Product Catalog Name:
    ApopTag® Plus Peroxidase In Situ Apoptosis Kit - (ApopTag® Plus Peroxidase In Situ Apoptosis Kit)
  • Polymerized type I collagen reduces chronic cyclosporine nephrotoxicity. 20139407

    BACKGROUND: Polymerized type I collagen (P-collagen) has been successfully used to reduce human hypertrophic scars due to its anti-fibrotic and anti-inflammatory properties. We therefore carried out a study to determine if P-collagen reduces functional and structural injury in chronic cyclosporine [cyclosporine A (CsA)] nephropathy. METHODS: Four groups of six male Wistar rats fed with a low sodium diet were treated with vehicle, P-collagen (0.8 mg/day, i.p.), CsA (15 mg/kg) or CsA + P-collagen for 15 days. Mean arterial pressure, renal blood flow and glomerular filtration rate were measured in all groups. Structural injury such as arteriolopathy, tubulo-interstitial fibrosis (TI-fibrosis) and positive apoptotic cells were quantified. The mRNA expression levels of transforming growth factor-beta (TGF-beta), kidney injury molecule (Kim-1), alpha-smooth muscle actin (alpha-SMA), glutathione peroxidase, catalase and Cu/Zn superoxide dismutase (SOD) as well as MnSOD were assessed. Antioxidant enzyme activity, renal lipoperoxidation and urinary excretion of oxygen peroxide (UH(2)O(2)V) were determined. RESULTS: Cyclosporine produced renal dysfunction and induced the development of arteriolopathy, TI-fibrosis and tubular apoptosis. These alterations were associated with increases in TGF-beta, Kim-1 and alpha-SMA mRNA levels as well as with a significant increase of oxidative stress and a reduction of SOD activity. P-Collagen partially ameliorated CsA-induced renal dysfunction and structural injury and prevented both tubular apoptosis and increased oxidative stress. This renoprotective effect was found to be associated with a reduction of TGF-beta, Kim-1 and alpha-SMA mRNA levels. CONCLUSIONS: This study has therefore demonstrated that P-collagen appears to have anti-fibrotic and anti-apoptotic properties and highlights the possibility that the compound might be useful in a strategy to reduce chronic CsA nephrotoxicity.,
    Document Type:
    Reference
    Product Catalog Number:
    S7101
    Product Catalog Name:
    ApopTag® Plus Peroxidase In Situ Apoptosis Kit - (ApopTag® Plus Peroxidase In Situ Apoptosis Kit)
  • Further studies on the potential contribution of acetaldehyde accumulation and oxidative stress in rat mammary tissue in the alcohol drinking promotion of breast cancer. 20623749

    There is available evidence supporting a positive association between alcohol intake and risk of breast cancer. However, there is limited information regarding possible mechanisms for this effect. Past studies from our laboratory suggest that acetaldehyde accumulation in mammary tissue after alcohol intake may be of particular relevance and that cytosolic and microsomal in situ bioactivation of ethanol to acetaldehyde and free radicals and the resulting stimulation of oxidative stress could be a significant early event related to tumor promotion. In the present studies repetitive alcohol drinking for 28 days was found to produce significant decreases in the mammary tissue content of GSH and alpha tocopherol and in glutathione S-transferase or glutathione reductase activities. In contrast, glutathione peroxidase activity was slightly increased. Malondialdehyde determinations did not show the occurrence of lipid peroxidation while the xylenol orange procedure gave positive results. The mammary microsomal metabolism of ethanol to acetaldehyde was not induced after an acute dose of ethanol or acetone able to induce the activity of its liver counterpart. The cytosolic pathway of alcohol metabolism instead was significantly enhanced by these two treatments. No increased generation of comet images was found either in mammary tissue or in liver under the experimental conditions tested. Results suggest that, while acetaldehyde accumulation in mammary tissue could be a critical event resulting from increasing production of acetaldehyde in situ plus an additional amount of it arriving via blood, other factors such as poor handling of the accumulated acetaldehyde could be also relevant.Copyright © 2010 John Wiley & Sons, Ltd.
    Document Type:
    Reference
    Product Catalog Number:
    S7101
    Product Catalog Name:
    ApopTag® Plus Peroxidase In Situ Apoptosis Kit - (ApopTag® Plus Peroxidase In Situ Apoptosis Kit)
  • Neurodegeneration and cellular stress in the retina and optic nerve in rat cerebral ischemia and hypoperfusion models. 18640247

    Experimental cerebral ischemia induces a stress response in neuronal and non-neuronal cells. In the present study we aimed to evaluate detailed cellular stress responses and neurodegenerative changes in the retinas in rat focal cerebral ischemia and hypoperfusion models involving invasive vascular manipulations. Independent groups of adult male Wistar rats were subjected to i) transient middle cerebral artery occlusion (tMCAO), ii) permanent middle cerebral artery occlusion (pMCAO), iii) cortical photothrombosis of the sensorimotor cortex using Rose Bengal dye or iv) bilateral common carotid artery occlusion (BCCAO). Rats were killed, and their eyes with the optic nerves enucleated and processed for histology, immunohistochemistry for neuronal nuclei (NeuN), glial fibrillary acidic protein (GFAP), hypoxia-inducible factor 1alpha (HIF-1alpha), c-fos, alphaB-crystallin, heat shock protein (HSP) 27, HSP60 and HSP70, and detection of DNA defragmentation. The total number of the retinal ganglion cell layer (RGCL) neurons and GFAP-immunoreactive astrocytes located in the nerve fiber layer were estimated using unbiased stereological counting. Our findings indicate that although permanent and transient MCAO does not cause detectable morphological alterations in the retina or optic nerve, it evokes ischemic stress as revealed by HIF-1alpha and HSPs expression in the RGCL neurons and reactive gliosis in the Müller cells. Severe neurodegenerative changes in the retina and optic nerve of the BCCAO rats are accompanied by a significant increase in immunoreactivities for the c-fos, HSP27 and HSP70 as compared with the sham-operated animals. The retinas from the ipsilateral side of the Rose Bengal model showed a significant decrease in the total number of NeuN-positive neurons in the RGCL as compared with the contralateral ones. However, these eyes did not differ between each other in the HSPs and HIF-1alpha expression or in the GFAP-immunoreactivity of the Müller cells. In conclusion, our data suggest differential expression of various HSPs in the retina and possibly their distinct roles in the cerebral ischemia-mediated stress response and neurodegeneration.
    Document Type:
    Reference
    Product Catalog Number:
    S7101
    Product Catalog Name:
    ApopTag® Plus Peroxidase In Situ Apoptosis Kit - (ApopTag® Plus Peroxidase In Situ Apoptosis Kit)