Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 410
Filtrar
1.
Zool Res ; 42(5): 650-659, 2021 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-34472226

RESUMO

Phosphatidylserine (PS) is distributed asymmetrically in the plasma membrane of eukaryotic cells. Phosphatidylserine flippase (P4-ATPase) transports PS from the outer leaflet of the lipid bilayer to the inner leaflet of the membrane to maintain PS asymmetry. The ß subunit TMEM30A is indispensable for transport and proper function of P4-ATPase. Previous studies have shown that the ATP11A and TMEM30A complex is the molecular switch for myotube formation. However, the role of Tmem30a in skeletal muscle regeneration remains elusive. In the current study, Tmem30a was highly expressed in the tibialis anterior (TA) muscles of dystrophin-null ( mdx) mice and BaCl 2-induced muscle injury model mice. We generated a satellite cell (SC)-specific Tmem30a conditional knockout (cKO) mouse model to investigate the role of Tmem30a in skeletal muscle regeneration. The regenerative ability of cKO mice was evaluated by analyzing the number and diameter of regenerated SCs after the TA muscles were injured by BaCl 2-injection. Compared to the control mice, the cKO mice showed decreased Pax7 + and MYH3 + SCs, indicating diminished SC proliferation, and decreased expression of muscular regulatory factors (MYOD and MYOG), suggesting impaired myoblast proliferation in skeletal muscle regeneration. Taken together, these results demonstrate the essential role of Tmem30a in skeletal muscle regeneration.


Assuntos
Proteínas de Membrana/metabolismo , Músculo Esquelético/fisiologia , Regeneração/fisiologia , Células Satélites de Músculo Esquelético/metabolismo , Animais , Proliferação de Células , Distrofina/genética , Distrofina/metabolismo , Antagonistas de Estrogênios/toxicidade , Regulação da Expressão Gênica/fisiologia , Genótipo , Proteínas de Membrana/genética , Camundongos , Camundongos Endogâmicos mdx , Camundongos Knockout , Músculo Esquelético/efeitos dos fármacos , Proteína MyoD/genética , Proteína MyoD/metabolismo , Miogenina/genética , Miogenina/metabolismo , Cadeias Pesadas de Miosina/genética , Cadeias Pesadas de Miosina/metabolismo , Fator de Transcrição PAX7/genética , Fator de Transcrição PAX7/metabolismo , Regeneração/genética , Tamoxifeno/toxicidade
2.
Environ Res ; 197: 111121, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33823193

RESUMO

Endoxifen is the main active metabolite of a common cytostatic drug, tamoxifen. Endoxifen has been recently detected in the final effluent of municipal wastewater treatment plants. The antiestrogenic activity of endoxifen could bring negative effects to aquatic life if released to the water environment. This study elucidated the fate and susceptibility of (E)- and (Z)-endoxifen (2 µg mL-1, 1:1 wt ratio between the two easily interchangeable isomers) in wastewater and receiving surface water to sunlight. Phototransformation by-products (PBPs) and their toxicity were determined. Sunlight reduced at least 83% of endoxifen concentration in wastewater samples, whereas in surface water samples, 60% of endoxifen was photodegraded after 180 min of the irradiation. In ultrapure water samples spiked with endoxifen, PBPs were mainly generated via con-rotatory 6π-photocyclization, followed by oxidative aromatization. These PBPs underwent secondary reactions leading to a series of PBPs with different molecular weights. Eight PBPs were identified and the toxicity analysis via the Toxicity Estimation Software Tool revealed that seven of these PBPs are more toxic than endoxifen itself. This is likely due to the formation of poly-aromatic core in the PBPs due to exposure to sunlight. Therefore, highly toxic PBPs may be generated if endoxifen is present in water and wastewater exposed to sunlight. The presence, fates and activities of these PBPs in surface water especially at locations close to treated wastewater discharge points should be investigated.


Assuntos
Neoplasias da Mama , Águas Residuárias , Feminino , Humanos , Luz Solar , Tamoxifeno/análogos & derivados , Tamoxifeno/toxicidade , Água
3.
J Food Biochem ; 45(2): e13615, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33491243

RESUMO

Reports over the years have demonstrated toxic side effect-including reproductive toxicity- of tamoxifen (TAM), a drug of choice in the management of primary breast cancer. Chlorogenic acid (CGA), a dietary polyphenol, reportedly elicits beneficial pharmacological effects. However, the impact of CGA on TAM-associated reproductive toxicity is absent in the literature. We, therefore, experimented on CGA's effect and TAM-mediated reproductive toxicity in rats. Cohorts of rats were treated with TAM (50 mg/kg) or co-treated with CGA (25 or 50 mg/kg) for 14 consecutive days. The result showed that treatment of CGA significantly increases testosterone, LH, and FSH levels compared to the TAM group. However, prolactin level was markedly decreased after pretreatment of CGA in TAM-treated rats. CGA abated TAM-induced decreases acid phosphatase, alkaline phosphatase, and antioxidant enzymes in the testis. CGA alleviated TAM-facilitated surges of reactive oxygen and nitrogen species, myeloperoxidase, nitric oxide, interleukin-1ß, and tumor necrosis factor-alpha in rats epididymis and testes. Additionally, CGA increased anti-inflammatory cytokine -interleukin-10-, suppressed caspase-3 activity, and reduced pathological lesions in the examined organs of rats co-treated with CGA and TAM. CGA phytoprotective effect improved reproductive function occasioned by TAM-mediated toxicities in rats, by abating oxido-inflammatory damages and downregulating apoptotic responses. PRACTICAL APPLICATIONS: CGA protects against the damaging oxido-inflammatory responses incumbent on TAM metabolism. As an antioxidant abundant in plant-derived foods, CGA reportedly protects against inflammatory damage, hypertension, and neurodegenerative diseases. We present evidence that CGA ameliorates TAM-induced reproductive dysfunction by suppressing oxidative and inflammation stress downregulate apoptosis and improve reproductive function biomarker in rats.


Assuntos
Ácido Clorogênico , Estresse Oxidativo , Animais , Antioxidantes/metabolismo , Antioxidantes/farmacologia , Ácido Clorogênico/metabolismo , Ácido Clorogênico/farmacologia , Masculino , Ratos , Tamoxifeno/metabolismo , Tamoxifeno/toxicidade , Testículo/metabolismo
4.
Br J Oral Maxillofac Surg ; 59(1): 52-57, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32723574

RESUMO

Cleft palate is a common birth defect in mammals, which can be caused by genetic or environmental factors, or both. Decades have witnessed that many environmental exposures during gestation extremely increase the incidence of cleft palate. Tamoxifen (TAM), a widely-used drug in treating breast cancer, has been reported to be associated with craniofacial defects including micrognathia and cleft palate in humans. However, its exact effects on the developing palate remain unclear. Here we took advantage of a mouse model to explore how TAM affects palatal development at the molecular level. We showed that excess exposure of TAM in the early embryonic stages indeed leads to cleft palate in mice. RNA-sequencing results strongly suggest the involvement of mitogen-activated protein kinase (MAPK) signalling in TAM-induced cleft palate. Interestingly, in the anterior portion of the TAM-treated palatal shelf, phosphorylated (p)-AKT and p-ERK1/2 were activated but p-p38 was inhibited, while in the posterior palate, the p-AKT increased but the levels of p-p38 and p-JNK decreased. We conclude that excess TAM exposure causes cleft palate defects in mice by regulating MAPK pathways, which implicates the importance of tightly-regulated MAPK signalling in palatal development. This study provides a basis for further exploration of the molecular aetiology of cleft palate defects caused by environmental factors and, based on our results, we would give a serious warning regarding prescription of TAM and potential cleft palate defects in animal models involving the inducible Cre-LoxP system.


Assuntos
Fissura Palatina , Animais , Fissura Palatina/induzido quimicamente , Camundongos , Palato , Transdução de Sinais , Tamoxifeno/toxicidade
5.
Arch. Soc. Esp. Oftalmol ; 95(10): 496-500, oct. 2020. ilus
Artigo em Espanhol | IBECS | ID: ibc-201401

RESUMO

INTRODUCCIÓN: El tamoxifeno es un antiestrógeno no esteroideo que actúa como antagonista en el tejido mamario, la retina neurosensorial y el epitelio pigmentario de la retina (EPR). La incidencia de sus efectos oculares varía entre el 0,9 y el 11%. MÉTODOS: Serie de casos. Se evaluaron tres pacientes de sexo femenino mediante estudio por imagen multimodal que recibieron tamoxifeno por cáncer de mama con el propósito de realizar el seguimiento y determinar si hay cambios luego de la suspensión del tratamiento. RESULTADOS: Las tres pacientes presentaron signos de retinopatía cristalina durante el seguimiento con tomografía de coherencia óptica de dominio espectral (SD-OCT). CONCLUSIÓN: El seguimiento mediante estudios de imagen multimodal permitió evaluar la progresión de los cambios aportando una valoración pronóstica. Los hallazgos encontrados (agudeza visual e imagen multimodal) confirmaron los resultados de estudios previos que indicaban que, a un determinado nivel de toxicidad, el daño era irreversible


INTRODUCTION: Tamoxifen is a non-steroidal anti-oestrogen that acts as an antagonist in breast tissue, neurosensory retina, and retinal pigment epithelium (RPE). The reported incidence of its ocular effects varies between 0.9% and 11%. METHODS: Case series. Multimodal image studies were used to evaluate three female patients who were receiving tamoxifen for breast cancer for the purpose of monitoring and determining whether there are changes after discontinuation of treatment. RESULTS: All three patients showed signs of crystalline retinopathy using spectral domain optical coherence tomography (SD-OCT) during follow-up. CONCLUSION: The follow-up using multimodal imaging studies allowed evaluating the progression of the changes, providing a prognostic assessment. The findings reported (visual acuity and multimodal imaging) confirmed the results of previous studies, indicating that, at a certain level of toxicity, the damage was irreversible


Assuntos
Humanos , Feminino , Pessoa de Meia-Idade , Idoso , Tamoxifeno/toxicidade , Doenças Retinianas/induzido quimicamente , Imagem Multimodal/métodos , Progressão da Doença , Doenças da Coroide/induzido quimicamente , Doenças Retinianas/patologia , Tomografia de Coerência Óptica/métodos , Acuidade Visual , Doenças da Coroide/diagnóstico
6.
Sci Rep ; 10(1): 10967, 2020 07 03.
Artigo em Inglês | MEDLINE | ID: mdl-32620803

RESUMO

We sought here to induce the excision of a large intragenic segment within the intact dystrophin gene locus, with the ultimate goal to elucidate dystrophin protein function and stability in striated muscles in vivo. To this end, we implemented an inducible-gene excision methodology using a floxed allele approach, demarcated by dystrophin exons 2-79, in complementation with a cardiac and skeletal muscle directed gene deletion system for spatial-temporal control of dystrophin gene excision in vivo. Main findings of this study include evidence of significant intact dystrophin gene excision, ranging from ~ 25% in heart muscle to ~ 30-35% in skeletal muscles in vivo. Results show that despite evidence of significant dystrophin gene excision, no significant decrease in dystrophin protein content was evident by Western blot analysis, at three months post excision in skeletal muscles or by 6 months post gene excision in heart muscle. Challenges of in vivo dystrophin gene excision revealed acute deleterious effects of tamoxifen on striated muscles, including a transient down regulation in dystrophin gene transcription in the absence of dystrophin gene excision. In addition, technical limitations of incomplete dystrophin gene excision became apparent that, in turn, tempered interpretation. Collectively, these findings are in keeping with earlier studies suggesting the dystrophin protein to be long-lived in striated muscles in vivo; however, more rigorous quantitative analysis of dystrophin stability in vivo will require future works in which more complete gene excision can be demonstrated, and without significant off-target effects of the gene deletion experimental platform per se.


Assuntos
Marcação de Genes/métodos , Músculo Esquelético/metabolismo , Miocárdio/metabolismo , Animais , Cardiomiopatias/induzido quimicamente , Distrofina/deficiência , Distrofina/genética , Feminino , Deleção de Genes , Expressão Gênica/efeitos dos fármacos , Técnicas de Silenciamento de Genes/métodos , Coração/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos mdx , Camundongos Knockout , Músculo Esquelético/efeitos dos fármacos , Distrofia Muscular Animal/genética , Distrofia Muscular Animal/metabolismo , Distrofia Muscular de Duchenne/genética , Distrofia Muscular de Duchenne/metabolismo , Estabilidade Proteica , Tamoxifeno/farmacologia , Tamoxifeno/toxicidade
7.
Gastroenterology ; 158(6): 1650-1666.e15, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32032583

RESUMO

BACKGROUND & AIMS: Gastric chief cells, a mature cell type that secretes digestive enzymes, have been proposed to be the origin of metaplasia and cancer through dedifferentiation or transdifferentiation. However, studies supporting this claim have had technical limitations, including issues with the specificity of chief cell markers and the toxicity of drugs used. We therefore sought to identify genes expressed specifically in chief cells and establish a model to trace these cells. METHODS: We performed transcriptome analysis of Mist1-CreERT-traced cells, with or without chief cell depletion. Gpr30-rtTA mice were generated and crossed to TetO-Cre mice, and lineage tracing was performed after crosses to R26-TdTomato mice. Additional lineage tracing experiments were performed using Mist1-CreERT, Kitl-CreERT, Tff1-Cre, and Tff2-Cre mice crossed to reporter mice. Mice were given high-dose tamoxifen or DMP-777 or were infected with Helicobacter pylori to induce gastric metaplasia. We studied mice that expressed mutant forms of Ras in gastric cells, using TetO-KrasG12D, LSL-KrasG12D, and LSL-HrasG12V mice. We analyzed stomach tissues from GPR30-knockout mice. Mice were given dichloroacetate to inhibit pyruvate dehydrogenase kinase (PDK)-dependent cell competition. RESULTS: We identified GPR30, the G-protein-coupled form of the estrogen receptor, as a cell-specific marker of chief cells in gastric epithelium of mice. Gpr30-rtTA mice crossed to TetO-Cre;R26-TdTomato mice had specific expression of GPR30 in chief cells, with no expression noted in isthmus stem cells or lineage tracing of glands. Expression of mutant Kras in GPR30+ chief cells did not lead to the development of metaplasia or dysplasia but, instead, led to a reduction in labeled numbers of chief cells and a compensatory expansion of neck lineage, which was derived from upper Kitl+ clones. Administration of high-dose tamoxifen, DMP-777, or H pylori decreased the number of labeled chief cells. Chief cells were eliminated from epithelia via GPR30- and PDK-dependent cell competition after metaplastic stimuli, whereas loss of GRP30 or inhibition of PDK activity preserved chief cell numbers and attenuated neck lineage cell expansion. CONCLUSIONS: In tracing studies of mice, we found that most chief cells are lost during metaplasia and therefore are unlikely to contribute to gastric carcinogenesis. Expansion of cells that coexpress neck and chief lineage markers, known as spasmolytic polypeptide-expressing metaplasia, does not occur via dedifferentiation from chief cells but, rather, through a compensatory response from neck progenitors to replace the eliminated chief cells.


Assuntos
Celulas Principais Gástricas/fisiologia , Mucosa Gástrica/patologia , Infecções por Helicobacter/patologia , Helicobacter pylori/patogenicidade , Receptores de Estrogênio/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Animais , Azetidinas/toxicidade , Comunicação Celular/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Linhagem da Célula/efeitos dos fármacos , Linhagem da Célula/fisiologia , Ácido Dicloroacético/administração & dosagem , Modelos Animais de Doenças , Mucosa Gástrica/citologia , Mucosa Gástrica/efeitos dos fármacos , Infecções por Helicobacter/microbiologia , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Metaplasia/induzido quimicamente , Metaplasia/microbiologia , Metaplasia/patologia , Camundongos , Camundongos Knockout , Piperazinas/toxicidade , Piruvato Desidrogenase Quinase de Transferência de Acetil/antagonistas & inibidores , Receptores de Estrogênio/genética , Receptores Acoplados a Proteínas G/genética , Células-Tronco/fisiologia , Tamoxifeno/toxicidade
8.
J Invest Dermatol ; 140(8): 1556-1565.e11, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-31987884

RESUMO

We analyzed the role of WIF1 in normal and acanthotic epidermis of 12-O-tetradecanoylphorbol-13-acetate (TPA) or all-trans-retinoic acid (ATRA)-treated and basal cell carcinoma (BCC)-bearing mice. WIF1 protein is located in the follicular infundibulum and interfollicular epidermis (IFE) in murine back skin. Within the hyperplastic epidermis of TPA- or ATRA-treated or BCC-bearing murine skin, WIF1 and Keratin 10 overlap in Ki67⁻ suprabasal layers, while basal epidermal layers expressing Ki67, and BCCs expressing Wif1 mRNA, are free of WIF1 protein. This is similar in human skin, with the exception that WIF1 protein is found in single Ki67⁻ basal epidermal cells in normal skin and additionally in Ki67+ cells in acanthotic skin. Wif1-deficiency enhances acanthosis of the murine BCC-associated epidermis, which is accompanied by an increase of Ki67+ and of Sca-1+ basal cells. WIF1 overexpression in allografted BCC-derived keratinocytes prevents growth and keratinization, involving enhanced phosphorylation of protein kinase C and extracellular signal-regulated kinase 1 and arguably factors secreted by the in vivo environment. In summary, WIF1 protein marks suprabasal layers in the normal IFE. It is also present in the epidermis overlaying BCCs where it diminishes proliferation of basal cells and production of differentiating suprabasal cells. In addition, WIF1 can prevent proliferation and keratinization of BCC-related keratinocytes.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Carcinoma Basocelular/patologia , Epiderme/patologia , Neoplasias Experimentais/patologia , Neoplasias Cutâneas/patologia , Proteínas Adaptadoras de Transdução de Sinal/genética , Animais , Carcinoma Basocelular/induzido quimicamente , Proliferação de Células/efeitos dos fármacos , Meios de Cultivo Condicionados/metabolismo , Epiderme/efeitos dos fármacos , Técnicas de Silenciamento de Genes , Células HEK293 , Humanos , Queratinócitos/patologia , Camundongos , Neoplasias Experimentais/induzido quimicamente , Cultura Primária de Células , Neoplasias Cutâneas/induzido quimicamente , Tamoxifeno/administração & dosagem , Tamoxifeno/toxicidade , Acetato de Tetradecanoilforbol/administração & dosagem , Acetato de Tetradecanoilforbol/toxicidade , Tretinoína/administração & dosagem , Tretinoína/toxicidade
9.
Toxicol Mech Methods ; 30(2): 115-123, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31532279

RESUMO

Tamoxifen (TAM) is used in breast cancer chemotherapy since its approval by the Food and Drug Administration in 1977. However, TAM therapy is accompanied with hepatotoxicity - a source of worry to clinicians. Oxidative stress and inflammation are the major implicated mechanisms contributing to TAM hepatotoxicity. In this study, we explored whether zinc (Zn) supplementation could prevent TAM-induced hepatotoxicity in female Wistar rats. Rats were subjected to oral pretreatment of Zn (100 mg/kg body weight (b.w.)/day) for 14 days against hepatic toxicity induced by single intraperitoneal administration of TAM (50 mg/kg b.w.) on day 13. TAM markedly elevated serum liver enzymes, whereas total protein and albumin considerably reduced. TAM caused prominent depletion of hepatic-reduced glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) activity. Also, TAM significantly increased malondialdehyde (MDA) level. Further, it raised liver levels of tumor necrosis factor-α (TNF-α), interleukin-1ß, (IL-1ß), interleukin-6 (IL-6), and nitric oxide (NO) confirmed by the liver histopathological alterations. The mechanistic inflammatory expression of inducible nitric oxide synthase (iNOS) and nuclear factor-kappa B (NF-ĸB), and expression of caspase-3 protein prominently increased. Zinc supplementation significantly modulated serum liver function markers, antioxidant enzymes, and GSH and MDA levels. Zinc downregulated the expression of cytokines, NO, iNOS, NF-ĸB and caspase-3, and ameliorated histopathological changes. Zinc protects against TAM-induced hepatotoxicity; it may serve as an adjuvant supplement for female patients undergoing TAM chemotherapy.


Assuntos
Apoptose/efeitos dos fármacos , Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , Cloretos/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Substâncias Protetoras/farmacologia , Tamoxifeno/toxicidade , Compostos de Zinco/farmacologia , Animais , Antioxidantes/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/patologia , Cloretos/administração & dosagem , Citocinas/metabolismo , Suplementos Nutricionais , Feminino , NF-kappa B/metabolismo , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo II/metabolismo , Substâncias Protetoras/administração & dosagem , Ratos , Ratos Wistar , Transdução de Sinais , Compostos de Zinco/administração & dosagem
10.
Sci Rep ; 9(1): 14140, 2019 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-31578396

RESUMO

Estrogen receptor-positive breast cancers are treated with tamoxifen, a drug that competitively inhibits the binding of estrogen to its receptor. Resistance to tamoxifen is a major hurdle in effective management of target breast cancer patient population. A number of dynamic changes within the tumor microenvironment, including the phenomenon of epithelial to mesenchymal transition (EMT), determine the response to endocrine therapy. EMT is marked by silencing or suppression of epithelial marker, E-Cadherin and we found significantly down-regulated E-Cadherin, among other epithelial markers, and a significantly up-regulated mesenchymal marker, Twist, among other mesenchymal markers, in a model system that comprised of tamoxifen sensitive MCF-7 cells and their tamoxifen-resistant counterparts, MCF-7-TAM, developed by chronic and escalating exposure of parental cells to tamoxifen. Further, E-cadherin, but not Twist, was differentially expressed in MCF-7-TAM cells because of differential methylation. Treatment with demethylating agent 5-azacytidine increased the expression of E-cadherin thus verifying a role of methylation in its silencing and, moreover, 5-azacytidine treatment also re-sensitized MCF-7-TAM cells to tamoxifen, as evaluated by assays for viability, apoptosis and migration potential. The 5-azacytidine effects were similar to effects of E-cadherin overexpression in MCF-7-TAM cells. This work describes novel mechanism of E-cadherin downregulation in tamoxifen resistant breast cancer cells. Further studies are needed to exploit this information for betterment of breast cancer therapy.


Assuntos
Neoplasias da Mama/metabolismo , Caderinas/genética , Metilação de DNA , Resistencia a Medicamentos Antineoplásicos , Antineoplásicos/toxicidade , Apoptose , Azacitidina/metabolismo , Caderinas/metabolismo , Movimento Celular , Regulação para Baixo , Feminino , Humanos , Células MCF-7 , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Receptores de Estrogênio/genética , Receptores de Estrogênio/metabolismo , Tamoxifeno/toxicidade , Proteína 1 Relacionada a Twist/genética , Proteína 1 Relacionada a Twist/metabolismo
11.
FASEB J ; 33(12): 14067-14082, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31657630

RESUMO

Glucocorticoids (GCs) are important hormones involved in the regulation of multiple physiologic functions. GCs are also widely used in anti-inflammatory/immunosuppressant drugs. GCs are synthesized by the adrenal cortex as part of the hypothalamus-pituitary-adrenal axis and also by intestinal epithelial cells, among other peripheral sites. GCs are one of the main therapy choices for the exacerbations of inflammatory bowel disease, but they are not useful to prolong remission, and development of tolerance with secondary treatment failure is frequent. Thus, GC actions at the intestinal epithelial level are of great importance, both physiologically and pharmacologically. We generated a tamoxifen-inducible nuclear receptor subfamily 3 group C member 1 (NR3C1)ΔIEC mouse model to study the effects of GCs on epithelial cells in vivo. Nr3c1 deletion in epithelial cells of the small intestine and colon was associated with limited colonic inflammation at 1 wk postdeletion, involving augmented epithelial proliferation and mucus production, plus local and systemic immune/inflammatory changes. This phenotype regressed substantially, but not completely, after 2 wk. The mechanism may involve augmented inflammatory signaling by epithelial cells or defective barrier function. We conclude that the epithelial GC receptor plays a significant role in colonic homeostasis in basal conditions, but its deficiency can be compensated in the short term. Future studies are required to assess the impact of Nr3c1 deletion in other conditions such as experimental colitis.-Aranda, C. J., Arredondo-Amador, M., Ocón, B., Lavín, J. L., Aransay, A. M., Martínez-Augustin, O., Sánchez de Medina, F. Intestinal epithelial deletion of the glucocorticoid receptor NR3C1 alters expression of inflammatory mediators and barrier function.


Assuntos
Células Epiteliais/metabolismo , Inflamação/metabolismo , Receptores de Glucocorticoides/metabolismo , Animais , Calgranulina A/genética , Calgranulina A/metabolismo , Calgranulina B/genética , Calgranulina B/metabolismo , Antagonistas de Estrogênios/toxicidade , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/fisiologia , Mucosa Intestinal/citologia , Camundongos , Camundongos Knockout , Camundongos Transgênicos , Receptores de Quimiocinas/genética , Receptores de Quimiocinas/metabolismo , Receptores de Glucocorticoides/genética , Tamoxifeno/toxicidade
12.
Am J Physiol Gastrointest Liver Physiol ; 317(4): G518-G530, 2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31369292

RESUMO

The sodium-dependent multivitamin transporter (SMVT; SLC5A6) is involved in intestinal absorption of vitamin B7 (biotin). We have previously shown that mice with an embryonic intestinal-specific SMVT knockout (KO) develop biotin deficiency and severe spontaneous intestinal inflammation in addition to growth retardation, developmental delays, and death within the first 6-7 wk of life. The profound morbidity and mortality associated with the SMVT-KO has limited our ability to further characterize the intestinal inflammation and other sequelae of this deletion in adult mice with a mature gut microbiota. To overcome this limitation, we generated an intestine-specific, tamoxifen-inducible, conditional SMVT-KO (SMVT-icKO). Our results showed that adult SMVT-icKO mice have reduced body weight, biotin deficiency, shorter colonic length, and bloody diarrhea compared with age- and sex-matched control littermates. All SMVT-icKO mice also developed spontaneous intestinal inflammation associated with induction of calprotectin (S100a8/S100a9), proinflammatory cytokines (IL-1ß, TNF-α, IFN-γ, and IL-6), and an increase in intestinal permeability. Additionally, the intestines of SMVT-icKO showed activation of the NF-κB pathway and the nucleotide-binding domain and leucine-rich repeat pyrin 3 domain (NLRP3) inflammasome. Notably, administration of broad-spectrum antibiotics reduced lethality and led to normalization of intestinal inflammation, proinflammatory cytokines, altered mucosal integrity, and reduced expression of the NLRP3 inflammasome. Overall, these findings support our conclusion that the biotin transport pathway plays an important role in the maintenance of intestinal homeostasis, and that NF-κB and the NLRP3 inflammasome, as well as gut microbiota, drive the development of intestinal inflammation when SMVT is absent.NEW & NOTEWORTHY This study demonstrates that deletion of the intestinal biotin uptake system in adult mice leads to the development of spontaneous gut inflammation and that luminal microbiota plays a role in its development.


Assuntos
Enterite/genética , Antagonistas de Estrogênios/toxicidade , Microbioma Gastrointestinal/efeitos dos fármacos , Intestinos/efeitos dos fármacos , NF-kappa B/efeitos dos fármacos , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Simportadores/metabolismo , Tamoxifeno/toxicidade , Envelhecimento , Animais , Biotina/metabolismo , Peso Corporal/efeitos dos fármacos , Colo/patologia , Citocinas/metabolismo , Diarreia/induzido quimicamente , Diarreia/microbiologia , Diarreia/patologia , Enterite/induzido quimicamente , Enterite/microbiologia , Intestinos/microbiologia , Camundongos , Camundongos Endogâmicos C57BL , Proteína 3 que Contém Domínio de Pirina da Família NLR/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Simportadores/efeitos dos fármacos , Simportadores/genética
13.
Life Sci ; 231: 116573, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-31207310

RESUMO

Hepatotoxicity is a common side effect encountered with tamoxifen (TAM) administration. Due to the great value of TAM in breast cancer treatment, hepato-protection is seriously recommended. AIMS: The present study investigated the hepato-protective effect of celecoxib (CX) against TAM-induced hepatotoxicity in rats. MAIN METHODS: Female rats were injected with TAM (45 mg/kg, i.p.) for 7 days and given CX (15 mg/kg, orally) 7 days before TAM injection, then continued for the following 7 days. KEY FINDINGS: Administration of CX for 14 days conferred significant hepatoprotection against TAM-induced hepatotoxicity indexed by decreased liver/body weight ratio, boosted cytoprotection and substantial reduction in serum LDH activity besides functional hepatic improvement; marked decrease in ALT, AST and ALP with significant elevation in serum albumin. Oxidant/antioxidants hemostasis was improved upon CX treatment with profound decrease in hepatic MDA content and elevation of GSH and SOD levels. Furthermore, hepatic content of NO decreased along with significant decrease in ASK-1, JNK and Bax levels as well as TNFα and caspase3 expression. Finally, CX administration resulted in obvious diminution of TAM-induced necrotic and apoptotic alterations. SIGNIFICANCE: Celecoxib might be used in combination with TAM in treatment protocol of breast to prevent liver injury induced by TAM and further clinical studies might be needed to approve this notion.


Assuntos
Celecoxib/farmacologia , Doença Hepática Induzida por Substâncias e Drogas/tratamento farmacológico , MAP Quinase Quinase 4/antagonistas & inibidores , MAP Quinase Quinase Quinase 5/antagonistas & inibidores , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Tamoxifeno/farmacologia , Animais , Antineoplásicos Hormonais/farmacologia , Antioxidantes/farmacologia , Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , Interações Medicamentosas , Feminino , Fígado/efeitos dos fármacos , Fígado/metabolismo , MAP Quinase Quinase 4/metabolismo , MAP Quinase Quinase Quinase 5/metabolismo , Fatores de Proteção , Ratos , Ratos Sprague-Dawley , Tamoxifeno/toxicidade
14.
Aquat Toxicol ; 213: 105220, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31202166

RESUMO

Tamoxifen (TAM) is an antiestrogenic agent and can enter the aquatic environment in wastewater. It has been reported that TAM can induce hepatic steatosis in vertebrates, however, the effects of TAM exposure on lipid metabolism of hepatopancreas in crustaceans remains unclear. In this study, four TAM concentrations (0, 6.7, 13.4 and 20 µg g-1 crab body weight) were injected into the swimming-leg of swimming crabs Portunus trituberculatus, as a means of evaluating the effects of TAM on the expression levels of lipid metabolism-related genes, lipid composition, and hepatopancreas histology. The results showed that the mRNA levels of three lipogenic related genes (diacylglycerol acyltransferase 1 (DGAT1), acetyl-CoA carboxylase (ACC) and fatty acyl desaturase (FAD)) decreased significantly in the 6.7 µg g-1 and 20 µg g-1 TAM treatments compare to the control. The mRNA levels of fatty acid synthase (FAS) decreased significantly in a dose-dependent manner as TAM concentration increased. The mRNA levels of two lipid catabolism-related genes (acyl-CoA oxidase (ACOX) and fatty acid transport protein (FATP)) were down-regulated among the three TAM treatments, while the enzyme activity and mRNA level of carnitine palmitoyltransferase I (CPT-I) was up-regulated by TAM treatments. Compared to the control, the lowest levels of total lipids and phospholipids were detected in the 6.7 µg g-1 TAM treatment, while the 20 µg g-1 TAM treatment had the lowest free fatty acids concentration. The 6.7 µg g-1 TAM treatment had the lowest percentages of 16:1n-7, 18:1n-9, 18:1n-7 and total monounsaturated fatty acids (∑MUFA), whilst simultaneously recording the highest percentages of 18:2n-6 and 20:2n-6 in this treatment. Moreover, histological observations indicated that TAM caused the walls of the hepatopancreatic tubules to become brittle, with a concurrent increase in the number of blister-like cells. These results suggest that TAM damages the hepatopancreas and leads to a reduction in hepatopancreatic lipid deposition in P. trituberculatus.


Assuntos
Braquiúros/metabolismo , Hepatopâncreas/metabolismo , Hepatopâncreas/patologia , Metabolismo dos Lipídeos/efeitos dos fármacos , Natação , Tamoxifeno/toxicidade , Animais , Braquiúros/efeitos dos fármacos , Carnitina O-Palmitoiltransferase/metabolismo , Ácidos Graxos não Esterificados/metabolismo , Feminino , Hepatopâncreas/efeitos dos fármacos , Metabolismo dos Lipídeos/genética , Oxirredução , Poluentes Químicos da Água/toxicidade
15.
J Pathol ; 248(2): 179-190, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30689202

RESUMO

In the mammalian stomach, the isthmus has been considered as a stem cell zone. However, various locations and proliferative activities of gastric stem cells have been reported. We focused here on the stem cell marker Bmi1, a polycomb group protein, aiming to elucidate the characteristics of Bmi1-expressing cells in the stomach and to examine their stem cell potential. We investigated the Bmi1-expressing cell lineage in Bmi1-CreERT; Rosa26-YFP, LacZ or Rosa26-Confetti mice. We examined the in vivo and ex vivo effects of Bmi1-expressing cell ablation by using Bmi1-CreERT; Rosa26-iDTR mice. The Bmi1 lineage was also traced during regeneration after high-dose tamoxifen-, irradiation- and acetic acid-induced mucosal injuries. In the lineage-tracing experiments using low-dose tamoxifen, Bmi1-expressing cells in the isthmus of the gastric antrum and corpus provided progeny bidirectionally, towards both the luminal and basal sides over 6 months. In gastric organoids, Bmi1-expressing cells also provided progeny. Ablation of Bmi1-expressing cells resulted in impaired gastric epithelium in both mouse stomach and organoids. After high-dose tamoxifen-induced gastric mucosal injury, Bmi1-expressing cell lineages expanded and fully occupied all gastric glands of the antrum and the corpus within 7 days after tamoxifen injection. After irradiation- and acetic acid-induced gastric mucosal injuries, Bmi1-expressing cells also contributed to regeneration. In conclusion, Bmi1 is a gastric stem cell marker expressed in the isthmus of the antrum and corpus. Bmi1-expressing cells have stem cell potentials, both under physiological conditions and during regeneration after gastric mucosal injuries. Copyright © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.


Assuntos
Complexo Repressor Polycomb 1/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Antro Pilórico/metabolismo , Células-Tronco/metabolismo , Ácido Acético , Animais , Biomarcadores/metabolismo , Diferenciação Celular , Linhagem da Célula , Proliferação de Células , Modelos Animais de Doenças , Fluoruracila/toxicidade , Regulação da Expressão Gênica no Desenvolvimento , Humanos , Camundongos Transgênicos , Complexo Repressor Polycomb 1/genética , Proteínas Proto-Oncogênicas/genética , Antro Pilórico/efeitos dos fármacos , Antro Pilórico/embriologia , Antro Pilórico/efeitos da radiação , Regeneração , Transdução de Sinais , Células-Tronco/efeitos dos fármacos , Células-Tronco/efeitos da radiação , Úlcera Gástrica/induzido quimicamente , Úlcera Gástrica/metabolismo , Úlcera Gástrica/patologia , Tamoxifeno/toxicidade
16.
Acta Pharmacol Sin ; 40(5): 608-619, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30315252

RESUMO

Tamoxifen (TMX) is an antiestrogen drug that is used in the treatment and prevention of all stages of estrogen-dependent breast cancer. Adverse effects of TMX include hepatotoxicity. In this study, we investigated the therapeutic effects of osthole, isolated from medicinal plants especially Fructus Cnidii, on TMX-induced acute liver injury in mice. Mice were injected with osthole (100 mg/kg, ip) or vehicle, followed by TMX (90 mg/kg, ip) 24 h later. We showed that a single injection of TMX-induced liver injury and oxidative stress. Pretreatment with osthole attenuated TMX-induced liver injury evidenced by dose-dependent reduction of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities. Pretreatment with osthole also blunted TMX-induced oxidative stress, evidenced by significant increase of reduced glutathione (GSH) as well as reduction of malondialdehyde (MDA) and hydrogen peroxide (H2O2). Consistently, osthole significantly enhanced the expressions of antioxidant genes (GPX1, SOD2, GCL-c, and G6pdh), but suppressed those of pro-oxidant genes (NOX2 and ACOX). Furthermore, osthole inhibited the production of inflammatory cytokines, reduced the metabolic activation of TMX, and promoted its clearance. We further revealed that osthole elevated hepatic cAMP and cGMP levels, but inhibition of PKA or PKG failed to abolish the hepatoprotective effect of osthole. Meanwhile, prominent phosphorylation of p38 was observed in liver in response to TMX, which was significantly inhibited by osthole. Pretreatment with SB203580, a p38 inhibitor, significantly attenuated TMX-induced increase of ALT and AST activities, reduced oxidative stress, and reversed the alterations of gene expression caused by TMX. Moreover, pretreatment with L-buthionine sulfoximine (BSO), an inhibitor of GSH synthesis, partly reversed the effect of osthole on TMX-induced liver injury. Consistently, pretreatment with N-acetyl-L-cysteine (NAC) significantly attenuated TMX-induced increase in ALT and AST activities. Notably, both BSO and NAC had no detectable effect on the phosphorylation levels of p38. Collectively, our results suggest that osthole prevents TMX hepatotoxicity by suppressing p38 activation and subsequently reducing TMX-induced oxidative damage.


Assuntos
Antioxidantes/uso terapêutico , Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , Cumarínicos/uso terapêutico , Moduladores de Receptor Estrogênico/toxicidade , Tamoxifeno/toxicidade , Alanina Transaminase/sangue , Alanina Transaminase/metabolismo , Animais , Antioxidantes/administração & dosagem , Aspartato Aminotransferases/sangue , Aspartato Aminotransferases/metabolismo , Cumarínicos/administração & dosagem , Citocinas/metabolismo , Relação Dose-Resposta a Droga , Moduladores de Receptor Estrogênico/administração & dosagem , Peróxido de Hidrogênio/metabolismo , Inflamação/prevenção & controle , Fígado/patologia , Masculino , Malondialdeído/metabolismo , Camundongos Endogâmicos BALB C , Estresse Oxidativo/efeitos dos fármacos , Tamoxifeno/administração & dosagem
17.
J Mol Cell Biol ; 11(1): 53-66, 2019 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-30239789

RESUMO

Skeletal muscle regeneration in adults is attributed to the presence of satellite stem cells that proliferate, differentiate, and eventually fuse with injured myofibers. However, the signaling mechanisms that regulate satellite cell homeostasis and function remain less understood. While IKKß-mediated canonical NF-κB signaling has been implicated in the regulation of myogenesis and skeletal muscle mass, its role in the regulation of satellite cell function during muscle regeneration has not been fully elucidated. Here, we report that canonical NF-κB signaling is induced in skeletal muscle upon injury. Satellite cell-specific inducible ablation of IKKß attenuates skeletal muscle regeneration in adult mice. Targeted ablation of IKKß also reduces the number of satellite cells in injured skeletal muscle of adult mice, potentially through inhibiting their proliferation and survival. We also demonstrate that the inhibition of specific components of the canonical NF-κB pathway causes precocious differentiation of cultured satellite cells both ex vivo and in vitro. Finally, our results highlight that the constitutive activation of canonical NF-κB signaling in satellite cells also attenuates skeletal muscle regeneration following injury in adult mice. Collectively, our study demonstrates that the proper regulation of canonical NF-κB signaling is important for the regeneration of adult skeletal muscle.


Assuntos
Quinase I-kappa B/metabolismo , Músculo Esquelético/fisiologia , Regeneração , Fator de Transcrição RelA/metabolismo , Animais , Apoptose , Diferenciação Celular , Proliferação de Células , Autorrenovação Celular , Quinase I-kappa B/antagonistas & inibidores , Quinase I-kappa B/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Desenvolvimento Muscular , Músculo Esquelético/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Células Satélites de Músculo Esquelético/citologia , Células Satélites de Músculo Esquelético/metabolismo , Transdução de Sinais , Tamoxifeno/toxicidade , Fator de Transcrição RelA/antagonistas & inibidores , Fator de Transcrição RelA/genética
18.
Toxicol Appl Pharmacol ; 363: 88-97, 2019 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-30503537

RESUMO

The endometrium is a particular sensitive target tissue for estradiol that is able to promptly modify its structure. Tamoxifen (TAM), a selective estrogen receptor modulator, was shown to promote a spectrum of uterine abnormalities, though the morphological and stereological effects of this drug in uterus is not clear. In this way, we have used an established model of ovariectomy followed by estradiol benzoate (EB) or TAM treatment and analyzed their effects in uterine histopathology and proliferation. Administration of EB promotes the unfolding and proliferation of the endometrium stroma, increasing uterine volume. No changes were found in uterine histomorphometric analysis upon TAM administration, except in the thickness of the luminal epithelium and endometrium layer. The latter may result from increased complexity and glandular volume density also observed in TAM treatment. In addition, EB induced PAX2 expression, an oncogene commonly found in epithelial tumors of the female genital tract, an effect that was weakened by previous TAM administration. Although treatments did not affect stroma cells proliferating index, in epithelial cells and, contrary to TAM, EB increased PCNA and not Ki67 expression. Collectively, our data suggest that the acute administration of TAM induces ERα-dependent atrophy of the uterine tissue and decreased the expression of proliferating cellular markers. On the contrary, if administered prior to EB, TAM is able to attenuate the action of the hormone in uterine morphology and biochemistry.


Assuntos
Antineoplásicos Hormonais/toxicidade , Tamoxifeno/toxicidade , Útero/patologia , Animais , Atrofia/induzido quimicamente , Atrofia/patologia , Proliferação de Células/efeitos dos fármacos , Células Epiteliais/efeitos dos fármacos , Estradiol/administração & dosagem , Estradiol/análogos & derivados , Receptor alfa de Estrogênio/metabolismo , Ciclo Estral/metabolismo , Feminino , Antígeno Ki-67/metabolismo , Ovariectomia , Fator de Transcrição PAX2/metabolismo , Antígeno Nuclear de Célula em Proliferação/metabolismo , Ratos , Ratos Wistar , Testes de Toxicidade Aguda , Útero/efeitos dos fármacos
19.
Exp Eye Res ; 180: 39-42, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30500365

RESUMO

The RAS gene family members, H-RAS, K-RAS, and N-RAS, are frequently mutated in human cancer. A subset of retinal tumors displays K-RAS mutations; however, the specific role of RAS activation on retinal tumor formation is unclear. To examine the role of RAS in retinal development, we overexpressed the mutant H-RAS gene (G12V) in retinal progenitor cells (RPCs), a multipotent progenitor cell population that gives rise to all six neuron types in the retina and to the Muller glia. The Msi1CreER mouse strain was used to induce mosaic activation of Ras (RasV12) in the RPCs of the postnatal retina. RAS-activated RPCs translocated to the basal part of the retina, differentiated into cells with glial characteristics, and underwent apoptosis. We next induced RAS activation in a large population of RPCs in the embryonic retina using the Pax6Cre mouse strain. In contrast to the phenotype observed in Msi1CreER;RasV12 mice, Ras-activated cells retained their apical attachment. Basal translocation was partially suppressed in the retina of Pax6Cre;RasV12 mice, indicating that basal translocation of Ras-activated cells was not cell autonomous. Notably, RAS-activated retinal cells were highly proliferative and promoted the formation of eye tumors in Pax6Cre;RasV12 mice. Together, our data indicate that the tumorigenicity of RAS activation in RPCs is context dependent, with tumor formation occurring when RAS activity is present in a large cluster of embryonic RPCs.


Assuntos
Células-Tronco Embrionárias/metabolismo , Neoplasias Oculares/patologia , Regulação da Expressão Gênica/fisiologia , Genes ras/genética , Células Fotorreceptoras de Vertebrados/metabolismo , Animais , Biomarcadores/metabolismo , Diferenciação Celular , Proliferação de Células , Antagonistas de Estrogênios/toxicidade , Neoplasias Oculares/metabolismo , Proteínas de Fluorescência Verde/metabolismo , Camundongos , Camundongos Transgênicos , Fator de Transcrição PAX6/genética , Tamoxifeno/toxicidade
20.
Ecotoxicol Environ Saf ; 169: 18-27, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30412894

RESUMO

The objective was to investigate endocrine-disrupting effects of polar compounds from oxidized frying oil. Estrogenicity of polar compounds was tested with a rat uterotrophic bioassay. Dietary oxidized frying oil (containing 51% polar compounds) or polar compounds isolated from it were incorporated into feed (in lieu of fresh soybean oil) and fed to ovariectomized rats, with or without treatment with exogenous ethynyl estradiol. Exogenous estrogen restored uterine weight, and caused histological abnormalities (stratified epithelia and conglomerate glands) as well as proliferation of uterine epithelial cells. However, tamoxifen or polar compounds reduced these effects. Furthermore, tamoxifen or polar compounds down-regulated uterine mRNA expression of estrogen receptor (ER)-target genes, implicating reduced ER activity in this hypo-uterotrophic effect. Inhibition of ER signaling and mitosis by polar compounds were attributed to reduced MAPK and AKT activation, as well as a reduced ligand binding domain-transactivity of ERα/ß. We concluded polar compounds from frying oil are potential endocrine-disrupting chemicals, with implications for food and environmental safety.


Assuntos
Disruptores Endócrinos/toxicidade , Antagonistas de Estrogênios/toxicidade , Animais , Culinária , Dieta , Estrogênios/farmacologia , Etinilestradiol/farmacologia , Feminino , Oxirredução , Ratos , Receptores de Estrogênio/antagonistas & inibidores , Receptores de Estrogênio/metabolismo , Óleo de Soja , Tamoxifeno/toxicidade , Útero/efeitos dos fármacos , Útero/metabolismo , Útero/patologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...