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1.
Poult Sci ; 96(1): 127-134, 2017 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-27287381

RESUMO

Novel strategies to minimize the excretion of phosphorus in swine and poultry are critical in minimizing environmental degradation. We have developed a synthetic peptide vaccine to produce autoantibodies to fibroblast growth factor 23 (FGF-23), a bone-derived hormone that blocks kidney phosphate resorption and indirectly reduces intestinal phosphate absorption. Single Comb White Leghorn laying hens, fed a standard diet (inorganic phosphorus, Pi = 0.4%), were immunized over the course of 4 weeks with either a FGF-23 peptide vaccine or adjuvant control (without FGF-23 peptide). At peak antibody titer to the peptide (week 5), 24-h excreta were collected and hens were blood sampled (represents 0.4% Pi treatment). Hens were then fed a 0.8% Pi diet and blood was sampled at 24 and 72 h and 24-h excreta were collected at 12 to 36 and 60 to 84 h (represents 0.8% Pi treatment). Increasing Pi from 0.4 to 0.8% increased (P < 0.05) percent excreta phosphorus, total 24-h phosphorus excretion, and plasma levels of FGF-23 and phosphate in either control or FGF-23 peptide vaccinated hens as early as the first sampling period. FGF-23 peptide vaccinated hens fed 0.4% Pi had reduced (P < 0.05) percent excreta phosphorus, total 24 h phosphorus excretion, and plasma levels of FGF-23 and iPTH, and increased (P < 0.05) plasma levels of phosphate and 1,25(OH)2D3 when compared to control vaccinated hens fed 0.4% Pi. In the first collection period post 0.8% Pi feeding, FGF-23 peptide vaccinated hens had reduced (P < 0.05) plasma levels of FGF-23 and iPTH, and increased (P < 0.05) plasma levels of phosphate and 1,25(OH)2D3, and tended to have reduced percent excreta phosphorus (P = 0.085) and total 24 h phosphorus excretion (P = 0.078) when compared to control vaccinated hens. Results during the second collection period post 0.8% Pi feeding were similar to that at the first collection period. These results are the first to show that the inhibition of FGF-23 action by a peptide vaccine (via neutralizing antibody) reduced phosphorus excretion. The approach presented provides new information on phosphorus metabolism in the laying hen.


Assuntos
Autoanticorpos/metabolismo , Proteínas Aviárias/metabolismo , Galinhas/fisiologia , Fatores de Crescimento de Fibroblastos/metabolismo , Fósforo/metabolismo , Animais , Feminino , Fator de Crescimento de Fibroblastos 23 , Homeostase , Hormônios/metabolismo , Vacinas/administração & dosagem
2.
Poult Sci ; 96(4): 878-885, 2017 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-27647928

RESUMO

Novel means to reduce phosphate input into poultry feeds and increase its retention would preserve world phosphate reserves and reduce environmental impact of poultry production. Here we show that a maternally derived antibody to a fibroblast growth factor-23 (FGF-23) peptide (GMNPPPYS) alleviated phosphorus deficiency in chicks fed low non-phytate phosphorus (nPP) diets. White Leghorn laying hens were vaccinated with either an adjuvant control or the synthetic FGF-23 peptide, and chicks with control or anti-FGF-23 maternal antibodies were fed a diet containing either 0.13 or 0.45% nPP (experiment 1), and 0.20 or 0.45% nPP (experiment 2) for 14 d. In both experiments, decreasing nPP from 0.45 to 0.13 or 0.20% decreased BW gain, G:F, excreta phosphorus, plasma phosphate, and plasma FGF-23 at all time periods examined (nPP main effect, P < 0.05). In experiment 1, chicks with maternal anti-FGF-23 antibody had increased tibiotarsi ash (d 14), and decreased excreta phosphate (d 7, 14) and plasma intact parathyroid hormone (d 7) when compared to chicks with control antibody (antibody main effect, P < 0.05). Mortality (d 7 to 14, 1 to 14), posture scores (d 7, 14) and bone lesion scores (d 14) decreased and plasma phosphate (d 14) increased in anti-FGF-23 chicks fed 0.13% nPP, compared to those with control antibody on the same diet (P < 0.05). In experiment 2, chicks with maternal anti-FGF-23 antibody had increased tibiotarsi ash (d 14), and plasma phosphate (d 14) and 1,25(OH)2D3 (d 14) levels, compared to chicks with control antibody (antibody main effect, P < 0.05). BW gain and G:F were increased in chicks with anti-FGF-23 antibody fed 0.20% nPP, compared to control antibody chicks on the same diet, at all time periods examined (P < 0.05). In conclusion, maternally-derived anti-FGF-23 antibody increased phosphorus retention in chicks fed diets containing either 0.13 or 0.20% nPP and thereby, reduced signs of phosphorus deficiency.


Assuntos
Anticorpos/imunologia , Fatores de Crescimento de Fibroblastos/imunologia , Necessidades Nutricionais , Fosfatos/deficiência , Fósforo na Dieta/metabolismo , Ração Animal/análise , Fenômenos Fisiológicos da Nutrição Animal , Animais , Galinhas , Dieta/veterinária , Feminino , Fator de Crescimento de Fibroblastos 23
3.
Poult Sci ; 95(2): 430-8, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26839414

RESUMO

Interleukin-10 (IL-10) mRNA levels are increased within intestinal mucosa after Eimeria infection. IL-10 apical receptor presence on enterocytes suggests IL-10 is secreted into the intestinal lumen. Increased IL-10 has been shown to be central to the pathogenesis of numerous intracellular pathogens; we hypothesize luminal secretion of IL-10 enables Eimeria spp. infection in chickens. This study examines intestine luminal IL-10 levels and performance in broilers challenged with Eimeria when fed an anti-IL-10 antibody. Chicks were fed a diet (1 to 21 d) with control or anti-IL-10 antibody (0.34 g egg yolk antibody powder/Kg diet) with a saline or 10× dose of Advent coccidiosis vaccine on d 3. One chick per pen was euthanized on days 2, 4, 7, 10, 13, 16, and 19 post-challenge, bled, and intestines were collected for luminal fluid IL-10 concentrations. Body weight and feed intake were measured on d 21, and oocyst shedding was assessed on d 7 post-challenge. A significant Eimeria × antibody interaction on d 21 body weight (P < 0.05) showed chicks fed control antibody, but not anti-IL-10, had significant reductions in body weight when challenged with Eimeria spp. Oocyst shedding was increased with Eimeria challenge, but dietary antibody had no effect. Plasma carotenoid levels were reduced in Eimeria challenged chicks 4, 7, 10, and 16 days post-challenge compared to unchallenged chicks. Lack of an Eimeria × antibody interaction showed anti-IL-10 was not protective against Eimeria-induced decreases in plasma carotenoids. Eimeria challenge increased intestine luminal IL-10 on days 4 and 7 post-challenge in the cecum and jejunum, respectively, compared to unchallenged. Dietary anti-IL-10 decreased luminal IL-10 in the ileum on day 2 post-challenge when compared to control antibody fed chicks. No interaction between Eimeria challenge and antibody was observed on intestine luminal contents of IL-10, suggesting anti-IL-10 was ineffective at preventing increased Eimeria-induced luminal IL-10. In conclusion, Eimeria challenge increased intestinal luminal IL-10 and anti-IL-10 was effective at preventing Eimeria-induced decreased body weight, however the mechanism anti-IL-10 antibody protects body weight during Eimeria challenge remains unknown.


Assuntos
Proteínas Aviárias/farmacologia , Coccidiose/veterinária , Suplementos Nutricionais , Interleucina-10/farmacologia , Doenças das Aves Domésticas/prevenção & controle , Vacinas Protozoárias/farmacologia , Ração Animal/análise , Animais , Infecções Assintomáticas , Proteínas Aviárias/administração & dosagem , Coccidiose/parasitologia , Coccidiose/prevenção & controle , Dieta/veterinária , Eimeria/fisiologia , Feminino , Interleucina-10/administração & dosagem , Intestinos/parasitologia , Doenças das Aves Domésticas/parasitologia , Vacinas Protozoárias/administração & dosagem , Distribuição Aleatória , Virulência
4.
Poult Sci ; 95(2): 439-46, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26772659

RESUMO

Eimeria spp. must be controlled in floor-reared poultry to prevent the onset of coccidiosis. Here we use an oral antibody to chicken IL-10 to prevent growth depression due to Eimeria spp. infection. Egg antibody directed against an antigenic peptide of IL-10 was produced in laying hens and measured using an ELISA. In the first experiment, egg yolk powder containing antibody to chicken IL-10 (vlpramqt conjugate) (anti-IL-10 yolk powder) was fed at 3.4 g/kg feed to determine growth response following mixed Eimeria spp. challenge. Chicks were fed either anti-IL-10 antibodies or control antibodies and challenged (d3) with either sterile saline or a 10× attenuated Eimeria spp. vaccine. Control-fed and Eimeria-challenged chicks grew 8.8% slower than those challenged with saline (P < 0.04), whereas anti-IL-10-fed Eimeria challenged chicks were not different from untreated controls. In the second trial a dose response was performed with doses of either 0 (control antibody), 0.34-, or 3.4-g anti-IL-10 yolk powder/kg feed. Control-fed, Eimeria-challenged chicks grew 10.6% slower than control saline-challenged chicks (P < 0.05); however, anti-IL-10-fed chicks fed either dose of anti-IL-10 were not different from saline-challenged chicks. Finally, the effect of anti-IL-10 on acquired immunity was investigated. Chicks were fed control or anti-IL-10 yolk powder and vaccinated with a 1× dose of Eimeria vaccine at d 3. After 14 d, antibody was removed from the diet. Chicks were either saline or 10× Eimeria challenged at d 17. We found that the anti-IL-10-fed chickens did not show a reduction in growth due to challenge; hence anti-IL-10 does not appear to affect adaptive immunity during the primary immunization. Overall, use of an antibody to IL-10 is a novel method in preventing adverse effects of Eimeria spp. infection in poultry.


Assuntos
Anticorpos Antiprotozoários/farmacologia , Proteínas Aviárias/metabolismo , Galinhas , Coccidiose/veterinária , Interleucina-10/metabolismo , Doenças das Aves Domésticas/prevenção & controle , Ração Animal/análise , Animais , Anticorpos Antiprotozoários/administração & dosagem , Galinhas/crescimento & desenvolvimento , Coccidiose/parasitologia , Coccidiose/prevenção & controle , Dieta/veterinária , Eimeria/fisiologia , Feminino , Doenças das Aves Domésticas/parasitologia
5.
Poult Sci ; 94(6): 1128-37, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25825784

RESUMO

Hyperimmunized hens are an effective means of generating large quantities of antigen specific egg antibodies that have use as oral supplements. In this study, we attempted to create a peptide specific antibody that produced outcomes similar to those of the human pharmaceutical, sevelamer HCl, used in the treatment of hyperphosphatemia (a sequela of chronic renal disease). Egg antibodies were generated against 8 different human intestinal sodium-dependent phosphate cotransporter 2b (NaPi2b) peptides, and hNaPi2b peptide egg antibodies were screened for their ability to inhibit phosphate transport in human intestinal Caco-2 cell line. Antibody produced against human peptide sequence TSPSLCWT (anti-h16) was specific for its peptide sequence, and significantly reduced phosphate transport in human Caco-2 cells to 25.3±11.5% of control nonspecific antibody, when compared to nicotinamide, a known inhibitor of phosphate transport (P≤0.05). Antibody was then produced against the mouse-specific peptide h16 counterpart (mouse sequence TSPSYCWT, anti-m16) for further analysis in a murine model. When anti-m16 was fed to mice (1% of diet as dried egg yolk powder), egg yolk immunoglobulin (IgY) was detected using immunohistochemical staining in mouse ileum, and egg anti-m16 IgY colocalized with a commercial goat anti-NaPi2b antibody. The effectiveness of anti-m16 egg antibody in reducing serum phosphate, when compared to sevelamer HCl, was determined in a mouse feeding study. Serum phosphate was reduced 18% (P<0.02) in mice fed anti-m16 (1% as dried egg yolk powder) and 30% (P<0.0001) in mice fed sevelamer HCl (1% of diet) when compared to mice fed nonspecific egg immunoglobulin. The methods described and the findings reported show that oral egg antibodies are useful and easy to prepare reagents for the study and possible treatment of select diseases.


Assuntos
Imunoglobulinas/imunologia , Fosfatos/sangue , Proteínas Cotransportadoras de Sódio-Fosfato/genética , Animais , Anticorpos/metabolismo , Células CACO-2 , Embrião de Galinha , Galinhas , Ensaio de Imunoadsorção Enzimática , Humanos , Imunoglobulinas/sangue , Imunoglobulinas/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Óvulo/metabolismo , Análise de Sequência de Proteína , Proteínas Cotransportadoras de Sódio-Fosfato/imunologia
6.
ACS Chem Biol ; 10(3): 844-54, 2015 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-25559929

RESUMO

Oligomers that contain both α- and ß-amino acid residues, or "α/ß-peptides", have emerged as promising mimics of signal-bearing polypeptides that can inhibit or augment natural protein-protein interactions. α/ß-Peptides that contain a sufficient proportion of ß residues evenly distributed along the sequence can be highly resistant to enzymatic degradation, which is favorable with regard to in vivo applications. Little is known, however, about recognition of α/ß-peptides by the immune system. Prior studies have focused almost entirely on examples that contain a single ß residue; such α/ß-peptides frequently retain the immunological profile of the analogous α-peptide. We have conducted α-peptide vs α/ß-peptide comparisons involving higher ß residue content, focusing on molecules with αααß and ααßαααß backbone repeat patterns. Among analogues of an 18-mer derived from the Bim BH3 domain and an 8-mer derived from secreted phospholipase-2 (sPLA2), we find that recognition by antibodies raised against the prototype α-peptide is suppressed by periodic α → ß replacements. Complementary studies reveal that antibodies raised against Bim BH3- or sPLA2-derived α/ß-peptides fail to recognize prototype α-peptides displaying identical side chain repertoires. Because polypeptides containing d-α-amino acid residues are of growing interest for biomedical applications, we included the enantiomer of the sPLA2-derived α-peptide in these studies; this d-peptide is fully competent as a hapten, but the resulting antibodies do not cross react with the enantiomeric peptide. Among analogues of the 9-mer CD8(+) T-cell viral epitope GP33, we observe that periodic α → ß replacements suppress participation in the MHC I + peptide + T-cell receptor ternary complexes that activate cytotoxic T-lymphocytes, due in part to disruption of MHC binding.


Assuntos
Anticorpos/química , Antígenos Virais/química , Proteínas Reguladoras de Apoptose/química , Epitopos/química , Proteínas de Membrana/química , Oligopeptídeos/química , Fosfolipases A2/química , Proteínas Proto-Oncogênicas/química , Sequência de Aminoácidos , Animais , Anticorpos/imunologia , Anticorpos/isolamento & purificação , Especificidade de Anticorpos , Antígenos Virais/imunologia , Proteínas Reguladoras de Apoptose/imunologia , Proteína 11 Semelhante a Bcl-2 , Sítios de Ligação , Galinhas , Ensaio de Imunoadsorção Enzimática , Epitopos/imunologia , Humanos , Cinética , Proteínas de Membrana/imunologia , Modelos Moleculares , Dados de Sequência Molecular , Oligopeptídeos/síntese química , Oligopeptídeos/imunologia , Fosfolipases A2/imunologia , Ligação Proteica , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , Proteínas Proto-Oncogênicas/imunologia , Receptores de Antígenos de Linfócitos T/química , Receptores de Antígenos de Linfócitos T/imunologia , Estereoisomerismo , Linfócitos T Citotóxicos/citologia , Linfócitos T Citotóxicos/imunologia
7.
J Invest Dermatol ; 135(4): 1098-1107, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25337691

RESUMO

We present here that heat-shock protein 90 (Hsp90) inhibitor 17-(allylamino)-17-demethoxygeldanamycin (17AAG), when topically applied to mouse skin, inhibits UVR-induced development of cutaneous squamous cell carcinoma (SCC). In these experiments, DMSO:acetone (1:40 v/v) solution of 17AAG (500 nmol) was applied topically to mouse skin in conjunction with each UVR exposure (1.8 kJ m(-2)). The UVR source was Kodacel-filtered FS-40 sun lamps (approximately 60% UVB and 40% UVA). In independent experiments with three separate mouse lines (SKH-1 hairless mice, wild-type FVB, and protein kinase C epsilon (PKCɛ)-overexpressing transgenic FVB mice), 17AAG treatment increased the latency and decreased both the incidence and multiplicity of UVR-induced SCC. Topical 17AAG alone or in conjunction with UVR treatments elicited neither skin nor systemic toxicity. 17AAG-caused inhibition of SCC induction was accompanied by a decrease in UVR-induced (1) hyperplasia, (2) Hsp90ß-PKCɛ interaction, and (3) expression levels of Hsp90ß, Stat3, pStat3Ser727, pStat3Tyr705, pAktSer473, and matrix metalloproteinase (MMP). The results presented here indicate that topical Hsp90 inhibitor 17AAG is effective in prevention of UVR-induced epidermal hyperplasia and SCC. One may conclude from the preclinical data presented here that topical 17AAG may be useful for prevention of UVR-induced inflammation and cutaneous SCC either developed in UVR-exposed or organ transplant population.


Assuntos
Benzoquinonas/farmacologia , Proteínas de Choque Térmico HSP90/metabolismo , Lactamas Macrocíclicas/farmacologia , Melanoma/metabolismo , Neoplasias Induzidas por Radiação/metabolismo , Neoplasias Cutâneas/metabolismo , Acetona/química , Animais , Dimetil Sulfóxido/química , Epiderme/metabolismo , Proteínas de Choque Térmico HSP90/antagonistas & inibidores , Humanos , Inflamação , Metaloproteinases da Matriz/metabolismo , Melanoma/prevenção & controle , Camundongos , Neoplasias Induzidas por Radiação/prevenção & controle , Proteína Quinase C-épsilon/metabolismo , Pele/efeitos dos fármacos , Neoplasias Cutâneas/tratamento farmacológico , Raios Ultravioleta , Melanoma Maligno Cutâneo
8.
J Skin Cancer ; 2013: 452425, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23738074

RESUMO

To find clues about the mechanism by which kinase C epsilon (PKC ε ) may impart susceptibility to ultraviolet radiation (UVR)-induced development of cutaneous squamous cell carcinomas (SCC), we compared PKC ε transgenic (TG) mice and their wild-type (WT) littermates for (1) the effects of UVR exposures on percent of putative hair follicle stem cells (HSCs) and (2) HSCs proliferation. The percent of double HSCs (CD34+ and α 6-integrin or CD34+/CD49f+) in the isolated keratinocytes were determined by flow cytometric analysis. Both single and chronic UVR treatments (1.8 kJ/m(2)) resulted in an increase in the frequency of double positive HSCs in PKC ε TG mice as compared to their WT littermates. To determine the rate of proliferation of bulge region stem cells, a 5-bromo-2'-deoxyuridine labeling (BrdU) experiment was performed. In the WT mice, the percent of double positive HSCs retaining BrdU label was 28.4 ± 0.6% compared to 4.0 ± 0.06% for the TG mice, an approximately 7-fold decrease. A comparison of gene expression profiles of FACS sorted double positive HSCs showed increased expression of Pes1, Rad21, Tfdp1 and Cks1b genes in TG mice compared to WT mice. Also, PKC ε over expression in mice increased the clonogenicity of isolated keratinocytes, a property commonly ascribed to stem cells.

9.
Curr Microbiol ; 67(3): 279-85, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23579313

RESUMO

Glucose-inhibited division (GidA) protein is widely distributed in nature, and is highly conserved among bacteria and eukarya. In our previous study, a gidA mutant was attenuated in both in vitro and in vivo models of Salmonella infection. Furthermore, deletion of gidA resulted in a marked reduction in the expression of many virulence genes and proteins, suggesting a role for GidA in the regulation of Salmonella virulence. In this study, the effect of different environmental conditions (glucose, EDTA, and pH 5) on GidA expression in Salmonella was examined. Transcriptional analysis using real-time RT-PCR and a ß-galactosidase assay, displayed no differences in gidA transcription and promoter activity in different environmental conditions. Conversely, semiquantitative Western blot analysis revealed a significant increase in the GidA expression in Salmonella when grown under different environmental conditions. Salmonella in vitro virulence assays showed an increased virulence potential in the environmental conditions correlating to the increase in GidA expression. Together, our data indicate that GidA expression is modulated under different environmental conditions which correlate to increased Salmonella in vitro virulence.


Assuntos
Proteínas de Bactérias/biossíntese , Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos , Salmonella typhimurium/efeitos dos fármacos , Salmonella typhimurium/genética , Western Blotting , Ácido Edético/metabolismo , Perfilação da Expressão Gênica , Genes Reporter , Glucose/metabolismo , Concentração de Íons de Hidrogênio , Reação em Cadeia da Polimerase em Tempo Real , Virulência , Fatores de Virulência/metabolismo , beta-Galactosidase/análise
10.
Carcinogenesis ; 33(1): 184-90, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22072620

RESUMO

Plumbagin (PL) (5-hydroxy-2-methyl-1,4-napthoquinone), a medicinal plant-derived naphthoquinone, was isolated from the roots of the Plumbago zeylanica L. (also known as Chitrak). The roots of P. zeylanica L. have been used in Indian medicine for >2500 years as an anti-atherogenic, cardiotonic, hepatoprotective and neuroprotective agent. We present here that topical application of non-toxic doses (100-500 nmol) of PL to skin elicits dose-dependent inhibition of ultraviolet radiation (UVR)-induced development of squamous cell carcinomas (SCC). In this experiment, FVB/N mice were exposed to UVR (2 kJ/m(2)) three times weekly from a bank of six Kodacel-filtered FS40 sunlamps (∼ 60% UVB and 40% UVA). Carcinoma incidence in mice treated with vehicle, 100, 200 or 500 nmol PL, at 44 weeks post-UVR, were 86, 80 (P = 0.67), 53 (P = 0.12) and 7% (P = 0.0075), respectively. Both vehicle and PL-treated mice gained weight and did not exhibit any signs of toxicity during the entire period of the experiment. Molecular mechanisms associated with inhibition of UVR-induced development of SCC involved induction of apoptosis and inhibition of cell proliferation. Specific findings are that PL treatment (i) inhibited UVR-induced DNA binding of activating protein-1, nuclear factor-kappaB, Stat3 transcription factors and Stat3-regulated molecules (cdc25A and Survivin); (ii) inhibited protein levels of pERK1/2, PI3K85, pAKTSer473, Bcl(2), BclxL, proliferating cell nuclear antigen and cell cycle inhibitory proteins p27 and p21 and (iii) increased UVR-induced Fas-associated death domain expression, poly (ADP-ribose) polymerase protein cleavage and Bax/Bcl(2) ratio. Taken together, our findings suggest that PL may be a novel agent for the prevention of skin cancer.


Assuntos
Antineoplásicos Fitogênicos/uso terapêutico , Carcinoma de Células Escamosas/prevenção & controle , Naftoquinonas/uso terapêutico , Neoplasias Induzidas por Radiação/prevenção & controle , Neoplasias Cutâneas/prevenção & controle , Animais , Sobrevivência Celular/efeitos dos fármacos , DNA/metabolismo , Feminino , Camundongos , NF-kappa B/metabolismo , Fator de Transcrição STAT3/metabolismo , Fator de Transcrição AP-1/metabolismo , Raios Ultravioleta
11.
J Invest Dermatol ; 130(1): 270-7, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19626035

RESUMO

Chronic exposure to UVR is the major etiologic factor in the development of human skin cancers including squamous-cell carcinoma (SCC). We have previously shown that protein Kinase C epsilon (PKCepsilon) transgenic mice on FVB/N background, which overexpress PKCepsilon protein approximately eightfold over endogenous levels in epidermis, exhibit about threefold more sensitivity than wild-type littermates to UVR-induced development of SCC. To determine whether it is PKCepsilon and not the mouse genetic background that determines susceptibility to UVR carcinogenesis, we cross-bred PKCepsilon FVB/N transgenic mice with SKH-1 hairless mice to generate PKCepsilon-overexpressing SKH-1 hairless mice. To evaluate the susceptibility of PKCepsilon SKH-1 hairless transgenic mice to UVR carcinogenesis, the mice were exposed to UVR (1-2 KJ m(-2)) three times weekly from a bank of six kodacel-filtered FS40 sunlamps. As compared with the wild-type hairless mice, PKCepsilon overexpression in SKH-1 hairless mice decreased the latency (12 weeks), whereas it increased the incidence (twofold) and multiplicity (fourfold) of SCC. The SKH hairless transgenic mice were observed to be as sensitive as FVB/N transgenic mice to UVR-induced development of SCC and expression of proliferative markers (proliferating cell nuclear antigen, signal transducers and activators of transcription 3, and extracellular signal-regulated kinase 1/2). The results indicate that PKCepsilon level dictates susceptibility, irrespective of genetic background, to UVR carcinogenesis.


Assuntos
Carcinoma de Células Escamosas/enzimologia , Carcinoma de Células Escamosas/genética , Proteína Quinase C-épsilon/genética , Neoplasias Cutâneas/enzimologia , Neoplasias Cutâneas/genética , Raios Ultravioleta/efeitos adversos , Animais , Núcleo Celular/metabolismo , Relação Dose-Resposta à Radiação , Epiderme/fisiologia , Epiderme/efeitos da radiação , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Feminino , Regulação Enzimológica da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Predisposição Genética para Doença , Masculino , Camundongos , Camundongos Pelados , Camundongos Transgênicos , Fosfatidilinositol 3-Quinases/metabolismo , Fosforilação/efeitos da radiação , Antígeno Nuclear de Célula em Proliferação/metabolismo , Proteína Quinase C-épsilon/metabolismo , Fator de Transcrição STAT3/metabolismo , Especificidade da Espécie
12.
Mol Carcinog ; 46(8): 646-53, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17583567

RESUMO

Protein kinase C (PKC) represents a large family of phosphatidylserine (PS)-dependent serine/threonine protein kinases. At least six PKC isoforms (alpha, delta, epsilon, eta, micro, and zeta) are expressed in epidermis. PKC is a major intracellular receptor for 12-O-tetradecanoylphorbol-13-acetate (TPA) and is also activated by a variety of stress factors including ultraviolet radiation (UVR). PKC isozymes (alpha, delta, epsilon, and eta), exhibit specificities to the development of skin cancer. PKCepsilon, a calcium-insensitive PKC isoform, is linked to the development of squamous cell carcinoma (SCC) elicited either by the 7,12-Dimethylbenzanthracene (DMBA)-TPA protocol or by repeated exposures to UVR. PKCepsilon overexpressing transgenic mice, when treated either with TPA or exposed to UVR, elicit similar responses such as inhibition of apoptosis, promotion of cell survival, and development of SCC. PKCepsilon overexpression increases Stat3 activation after either TPA treatment or UVR exposure. Both PKCepsilon and signal transducers and activators of transcription-3 (Stat3) are implicated in the development of SCC. However, the link between PKCepsilon and Stat3 remains elusive. We found that PKCepsilon interacts with Stat3. PKCepsilon interaction with Stat3 was dependent upon UVR treatment. In reciprocal immunoprecipitation/blotting experiments, Stat3 coimmunoprecipitated with PKCepsilon. Colocalization of PKCepsilon with Stat3 was confirmed by double immunofluorescence staining. PKCepsilon interaction with Stat3 was PKCepsilon isoform specific and was not observed with other protein kinases. As observed in vitro with immunocomplex kinase assay with immunopurified PKCepsilon and Stat3, PKCepsilon phosphorylated Stat3 at the serine 727 residue. PKCepsilon depletion prevented Stat3Ser727 phosphorylation, Stat3 DNA binding, and transcriptional activity. The results presented indicate that PKCepsilon mediates Stat3 activation.


Assuntos
Carcinoma de Células Escamosas/etiologia , Proteína Quinase C-épsilon/metabolismo , Fator de Transcrição STAT3/metabolismo , Neoplasias Cutâneas/etiologia , Animais , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/patologia , Humanos , Fosforilação , Neoplasias Cutâneas/metabolismo , Neoplasias Cutâneas/patologia
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