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1.
ACS Omega ; 9(18): 20243-20252, 2024 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-38737063

RESUMO

This research explores the crystallization process of honey during storage with a focus on its dissolution dynamics and essential characteristics. The investigation includes the examination of the effects of heat treatment at different temperatures (45-90 °C) and durations (23-960 min) on the induced crystallization of honey at 14 °C. Various analyses were conducted, including pH, acidity, color, sugar profile, phenolic and flavonoid contents, DPPH-scavenging activity, hydroxymethylfurfural (HMF), viscosity, and sensory attributes. The results indicated a reduction in the moisture content and pH, an increase in acidity, and higher levels of HMF at elevated temperatures. While the ash content remained relatively unchanged, variables such as color, glucose, fructose, total phenol, flavonoid, and antioxidant content exhibited variations with temperature. Viscosity decreased with an increase in temperature, suggesting Newtonian behavior and implying potential colloidal changes. Consumer sensory tests revealed significant differences among samples, with honey treated at 75 °C demonstrating superior physicochemical and sensory attributes. This study offers valuable insights into the dynamics of crystallized honey, providing information for both production practices and understanding consumer preferences.

2.
J Allergy Clin Immunol Glob ; 3(3): 100259, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38779310

RESUMO

Background: The skin microbiome is disrupted in atopic dermatitis (AD). Existing research focuses on moderate to severe, unmedicated disease. Objective: We sought to investigate metagenomic- and culture-based bacterial strain-level differences in mild, medicated AD and the effects these have on human keratinocytes (HKs). Methods: Skin swabs from anterior forearms were collected from 20 pediatric participants (11 participants with AD sampled at lesional and nonlesional sites and 9 age- and sex-matched controls). Participants had primarily mild to moderate AD and maintained medication use. Samples were processed for microbial metagenomic sequencing and bacterial isolation. Isolates identified as Staphylococcus aureus were tested for enterotoxin production. HK cultures were treated with cell-free conditioned media from representative Staphylococcus species to measure barrier effects. Results: Metagenomic sequencing identified significant differences in microbiome composition between AD and control groups. Differences were seen at the species and strain levels for Staphylococci, with S aureus found only in participants with AD and differences in Staphylococcus epidermidis strains between control and AD swabs. These strains showed differences in toxin gene presence, which was confirmed in vitro for S aureus enterotoxins. The strain from the participant with the most severe AD produced enterotoxin B levels more than 100-fold higher than the other strains (P < .001). Strains also displayed differential effects on HK metabolism and barrier function. Conclusions: Strain-level differences in toxin genes from Staphylococcus strains may explain varying effects on HK, with S aureus and non-aureus strains negatively affecting viability and barrier function. These differences are likely important in AD pathogenesis.

3.
Front Nutr ; 10: 1114076, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36742426

RESUMO

COVID-19 is a severe acute respiratory syndrome that mainly affects the human respiratory system. Unhealthy nutritional habits and obesity are expected as consequences of protective measures including quarantine. Obesity, in its growing prevalence, is a worldwide health issue associated with worsening health conditions. This is a cross-sectional study to assess the impact of the COVID-19 pandemic on obesity among Jordanian adults and across epidemiological statuses. Participants were randomly selected, and the survey was distributed on social media networking sites. A total of 672 subjects were surveyed and participated in the study between March and June 2021 via Google Form questionnaire. The results indicated that 74.4% of participants reported that they did not do any physical activity, and 43.5% changed their lifestyle and eating habits for the worse. During the COVID-19 pandemic, almost half of the participants reported an increase in hunger, consuming 3-4 meals/day, and consuming < 1 liter of water/day. Additionally, more than half of the participants reported no change in fat, cereals, and protein consumption, 46.4 % had no change in fruit and vegetable consumption, and 50.6% increased their consumption of sweets. Our results showed a significant increase in the self-reported BMI categories during the COVID-19 pandemic for all ages (p < 0.001). Change in weight and BMI was significantly associated with marital status, education level, living place, family size, family working members, and working status. Participants across all epidemiological statuses displayed a statistically significant increase in BMI. This study was conducted to observe the impacts of the COVID-19 pandemic on health behaviors and obesity among Jordanian adults and across epidemiological statuses. We found that there were significant negative changes in the lifestyle (physical activity) and eating behaviors of Jordanians during the COVID-19 quarantine which in turn increased their body weight and changed the obesity rate.

4.
ACS Omega ; 8(38): 34448-34457, 2023 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-37779931

RESUMO

Okra (Abelmoschus esculentus L.) is known for its high nutritional value, including its content of phytochemicals. This study aims to investigate the effect of drying and freezing conditions on the phytochemical content of okra. Our results indicated that both air-drying and freezing okra during 6 months of storage showed a significant decrease in total phenolic content, flavonoid content, anthocyanin content, and antioxidant activity. Furthermore, higher levels of phytochemicals were found for okra samples treated with Na2SO4 solution when compared to untreated okra. The freezing process appeared to better preserve the content of the investigated phytochemicals when compared to the decrease after drying. Our research has determined that both immersing and freezing okra samples consistently yielded better results in the preservation of phytochemical properties over time, compared to other methods. This study is important for the food industry, as it highlights the importance of proper storage methods to retain the nutritional value of okra.

5.
Sci Adv ; 9(26): eadg3736, 2023 06 30.
Artigo em Inglês | MEDLINE | ID: mdl-37390211

RESUMO

Immune checkpoint inhibitor (ICI) therapy is effective against many cancers for a subset of patients; a large percentage of patients remain unresponsive to this therapy. One contributing factor to ICI resistance is accumulation of monocytic myeloid-derived suppressor cells (M-MDSCs), a subset of innate immune cells with potent immunosuppressive activity against T lymphocytes. Here, using lung, melanoma, and breast cancer mouse models, we show that CD73-expressing M-MDSCs in the tumor microenvironment (TME) exhibit superior T cell suppressor function. Tumor-derived PGE2, a prostaglandin, directly induces CD73 expression in M-MDSCs via both Stat3 and CREB. The resulting CD73 overexpression induces elevated levels of adenosine, a nucleoside with T cell-suppressive activity, culminating in suppression of antitumor CD8+ T cell activity. Depletion of adenosine in the TME by the repurposed drug PEGylated adenosine deaminase (PEG-ADA) increases CD8+ T cell activity and enhances response to ICI therapy. Use of PEG-ADA can therefore be a therapeutic option to overcome resistance to ICIs in cancer patients.


Assuntos
Células Supressoras Mieloides , Animais , Camundongos , Adenosina , Imunoterapia , Terapia de Imunossupressão , Imunossupressores
6.
Oncoimmunology ; 8(3): 1561119, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30723593

RESUMO

The antigenic similarity between embryos and tumors has raised the idea of using embryonic material as a preventative vaccine against neoplastic disease. Indeed, we have previously reported that a vaccine comprises allogeneic murine embryonic stem cells (ESCs) and murine fibroblasts expressing GM-CSF (to amplify immune responses) successfully blocks the outgrowth of an implantable cancer (Lewis lung carcinoma; LLC) and lung tumors generated in mice using a combination of a mutagen followed by chronic pulmonary inflammation. However, such a vaccine is obviously impractical for application to humans. The use of fibroblasts to generate GM-CSF is needlessly complicated, and intact whole ESCs carry the hazard of generating embryomas/teratomas. Here, we report the successful application of an alternative prophylactic vaccine comprises exosomes derived from murine ESCs engineered to produce GM-CSF. Vaccination of mice with these exosomes significantly slowed or blocked the outgrowth of implanted LLC while control exosomes lacking GM-CSF were ineffective. Examination of tumor-infiltrating immune cells from mice vaccinated with the GM-CSF-expressing exosomes showed robust tumor-reactive CD8+ T effector responses, Th1 cytokine responses, and higher CD8+ T effector/CD4+CD25+Foxp3+ T regulatory cell ratio in the tumors. We conclude that a similar vaccine derived from GM-CSF- expressing human ESCs can be employed as a preventative vaccine for humans with an increased risk of developing cancer.

7.
Oncotarget ; 7(51): 84128-84141, 2016 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-27566591

RESUMO

Recent studies provide compelling evidence that melanoma is initiated and maintained by a small population of malignant cells called cancer-initiating cells (CICs) that exhibit stem-cell-like properties. Observations that CICs have a distinct biology when compared to that of the bulk tumor cells and, importantly, are resistant to chemotherapies and radiation, suggest that CICs are involved in invasion, metastasis, and ultimately relapse. Lunasin, a bioactive peptide present in soybean, has both chemopreventive activity and chemotherapeutic activity against multiple cancer types. In this study, we tested the potential of Lunasin to specifically target CICs in melanoma tumor cell populations. In vitro studies using human melanoma cell lines showed that Lunasin treatment decreased the size of a subpopulation of melanoma cells expressing the surrogate CIC marker, Aldehyde Dehydrogenase, concomitant with a reduction in the ability to form colonies in soft agar assays, and reduced tumor growth in mouse xenografts. Similarly, Lunasin inhibited colony formation by isolated melanoma CICs in soft agar and reduced oncosphere formation in vitro and substantially inhibited tumor growth in mouse xenografts. Mechanistic studies revealed that Lunasin treatment of isolated melanoma CICs induced expression of the melanocyte-associated differentiation markers Tyrosinase and Microphthalmia-associated Transcription Factor concomitant with reduced expression of the stemness factor NANOG. These findings document for the first time that Lunasin has significant therapeutic activity against melanoma by specifically targeting melanoma CICs, and inducing a more differentiated, non-CIC phenotype. Thus, Lunasin may represent a novel therapeutic option for both chemoresistant and advanced metastatic melanoma management.


Assuntos
Melanoma/tratamento farmacológico , Células-Tronco Neoplásicas/efeitos dos fármacos , Proteínas de Plantas/farmacologia , Ensaios Antitumorais Modelo de Xenoenxerto , Aldeído Desidrogenase/metabolismo , Animais , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Humanos , Masculino , Melanoma/metabolismo , Melanoma/patologia , Camundongos Nus , Modelos Biológicos , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/patologia , Carga Tumoral/efeitos dos fármacos
8.
Cancer Immunol Res ; 4(2): 101-12, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26603621

RESUMO

Highly aggressive cancers "entrain" innate and adaptive immune cells to suppress antitumor lymphocyte responses. Circulating myeloid-derived suppressor cells (MDSC) constitute the bulk of monocytic immunosuppressive activity in late-stage melanoma patients. Previous studies revealed that monocyte-derived macrophage migration inhibitory factor (MIF) is necessary for the immunosuppressive function of tumor-associated macrophages and MDSCs in mouse models of melanoma. In the current study, we sought to determine whether MIF contributes to human melanoma MDSC induction and T-cell immunosuppression using melanoma patient-derived MDSCs and an ex vivo coculture model of human melanoma-induced MDSC. We now report that circulating MDSCs isolated from late-stage melanoma patients are reliant upon MIF for suppression of antigen-independent T-cell activation and that MIF is necessary for maximal reactive oxygen species generation in these cells. Moreover, inhibition of MIF results in a functional reversion from immunosuppressive MDSC to an immunostimulatory dendritic cell (DC)-like phenotype that is at least partly due to reductions in MDSC prostaglandin E(2) (PGE(2)). These findings indicate that monocyte-derived MIF is centrally involved in human monocytic MDSC induction/immunosuppressive function and that therapeutic targeting of MIF may provide a novel means of inducing antitumor DC responses in late-stage melanoma patients.


Assuntos
Fatores Inibidores da Migração de Macrófagos/metabolismo , Melanoma/imunologia , Melanoma/metabolismo , Células Mieloides/imunologia , Células Mieloides/metabolismo , Animais , Biomarcadores , Diferenciação Celular , Linhagem Celular Tumoral , Modelos Animais de Doenças , Humanos , Imunofenotipagem , Masculino , Melanoma/patologia , Camundongos , Camundongos Transgênicos , Células Mieloides/patologia , Gradação de Tumores , Estadiamento de Neoplasias , Fenótipo , Espécies Reativas de Oxigênio/metabolismo
9.
Cancer Lett ; 347(1): 139-50, 2014 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-24513177

RESUMO

COUP-TFII is reduced in endocrine-resistant breast cancer cells and is negatively associated with tumor grade. Transient re-expression of COUP-TFII restores antiestrogen sensitivity in resistant LCC2 and LCC9 cells and repression of COUP-TFII results in antiestrogen-resistance in MCF-7 endocrine-sensitive cells. We addressed the hypothesis that reduced COUP-TFII expression in endocrine-resistant breast cancer cells results from epigenetic modification. The NR2F2 gene encoding COUP-TFII includes seven CpG islands, including one in the 5' promoter and one in exon 1. Treatment of LCC2 and LCC9 endocrine-resistant breast cancer cells with 5-aza-2'-deoxycytidine (AZA), a DNA methyltransferase (DNMT) inhibitor, +/- trichostatin A (TSA), a histone deacetylase (HDAC) inhibitor, increased COUP-TFII suggesting that the decrease in COUP-TFII is mediated by epigenetic changes. Methylation-specific PCR (MSP) revealed higher methylation of NR2F2 in the first exon in LCC2 and LCC9 cells compared to MCF-7 cells and AZA reduced this methylation. Translational importance is suggested by Cancer Methylome System (CMS) analysis revealing that breast tumors have increased COUP-TFII (NR2F2) promoter and gene methylation versus normal breast.


Assuntos
Antimetabólitos Antineoplásicos/farmacologia , Azacitidina/análogos & derivados , Neoplasias da Mama/metabolismo , Fator II de Transcrição COUP/metabolismo , Moduladores de Receptor Estrogênico/farmacologia , Ácidos Hidroxâmicos/farmacologia , Azacitidina/farmacologia , Neoplasias da Mama/patologia , Fator II de Transcrição COUP/genética , Ilhas de CpG , Metilação de DNA , Decitabina , Resistencia a Medicamentos Antineoplásicos , Receptor beta de Estrogênio/genética , Feminino , Humanos , Células MCF-7 , Reação em Cadeia da Polimerase em Tempo Real
10.
Int J Oncol ; 44(4): 1365-75, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24534923

RESUMO

Endocrine therapies have been successfully used for breast cancer patients with estrogen receptor α (ERα) positive tumors, but ~40% of patients relapse due to endocrine resistance. ß-glucans are components of plant cell walls that have immunomodulatory and anticancer activity. The objective of this study was to examine the activity of ß-D-glucan, purified from barley, in endocrine-sensitive MCF-7 versus endocrine-resistant LCC9 and LY2 breast cancer cells. ß-D-glucan dissolved in DMSO but not water inhibited MCF-7 cell proliferation in a concentration-dependent manner as measured by BrdU incorporation with an IC50 of ~164 ± 12 µg/ml. ß-D-glucan dissolved in DMSO inhibited tamoxifen/endocrine-resistant LCC9 and LY2 cell proliferation with IC50 values of 4.6 ± 0.3 and 24.2 ± 1.4 µg/ml, respectively. MCF-10A normal breast epithelial cells showed a higher IC50 ~464 µg/ml and the proliferation of MDA-MB-231 triple negative breast cancer cells was not inhibited by ß-D-glucan. Concentration-dependent increases in the BAX/BCL2 ratio and cell death with ß-D-glucan were observed in MCF-7 and LCC9 cells. PCR array analysis revealed changes in gene expression in response to 24-h treatment with 10 or 50 µg/ml ß-D-glucan that were different between MCF-7 and LCC9 cells as well as differences in basal gene expression between the two cell lines. Select results were confirmed by quantitative real-time PCR demonstrating that ß-D-glucan increased RASSF1 expression in MCF-7 cells and IGFBP3, CTNNB1 and ERß transcript expression in LCC9 cells. Our data indicate that ß-D-glucan regulates breast cancer-relevant gene expression and may be useful for inhibiting endocrine-resistant breast cancer cell proliferation.


Assuntos
Proliferação de Células/efeitos dos fármacos , Expressão Gênica/efeitos dos fármacos , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , beta-Glucanas/farmacologia , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos , Receptor alfa de Estrogênio/metabolismo , Receptor beta de Estrogênio/biossíntese , Feminino , Regulação Neoplásica da Expressão Gênica , Células HEK293 , Humanos , Proteína 3 de Ligação a Fator de Crescimento Semelhante à Insulina/biossíntese , Células MCF-7 , Fator 1 Nuclear Respiratório/biossíntese , Fator 1 Nuclear Respiratório/genética , Proteínas Supressoras de Tumor/biossíntese , beta Catenina/biossíntese
11.
Mol Cell Endocrinol ; 384(1-2): 134-42, 2014 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-24486192

RESUMO

Mice with a deletion of the hypothalamic basic helix-loop-helix transcription factor Nhlh2 display adult onset obesity. We have previously shown that Nhlh2 expression is induced by leptin. In this study, we identify a small proximal leptin-responsive promoter region in the Nhlh2 gene. This 163bp promoter contains five putative binding sites for the leptin-activated Stat3 transcription factor, and two putative binding sites for the NFκB transcription factor. Results of mutagenesis studies reveal that deletion of the NFκB sites have little effect, mutagenesis of the third Stat3 site eliminates both leptin-induced and basal expression of Nhlh2. Mutagenesis of the 4th and 5th sites eliminates leptin-induced expression, and increases basal expression above the WT promoter. Stat3 can be preferentially pulled down from leptin-treated mouse hypothalamic chromatin extracts. This study identifies leptin-induced Stat3 transcription factor as the major transcriptional regulator of Nhlh2. As Nhlh2 transcriptionally regulates genes within the melanocortin pathway, these findings have implications for human body weight control.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Regulação da Expressão Gênica , Hipotálamo/metabolismo , Leptina/genética , Fator de Transcrição STAT3/genética , Animais , Sequência de Bases , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Sítios de Ligação , Linhagem Celular , Genes Reporter , Humanos , Hipotálamo/citologia , Leptina/metabolismo , Luciferases/genética , Luciferases/metabolismo , Camundongos , Dados de Sequência Molecular , NF-kappa B/genética , NF-kappa B/metabolismo , Regiões Promotoras Genéticas , Ligação Proteica , Fator de Transcrição STAT3/metabolismo , Homologia de Sequência do Ácido Nucleico , Transdução de Sinais , beta-Galactosidase/genética , beta-Galactosidase/metabolismo
12.
Steroids ; 78(1): 15-25, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23123738

RESUMO

Dehydroepiandrosterone (DHEA) levels were reported to associate with increased breast cancer risk in postmenopausal women, but some carcinogen-induced rat mammary tumor studies question this claim. The purpose of this study was to determine how DHEA and its metabolites affect estrogen receptors α or ß (ERα or ERß)-regulated gene transcription and cell proliferation. In transiently transfected HEK-293 cells, androstenediol, DHEA, and DHEA-S activated ERα. In ERß transfected HepG2 cells, androstenedione, DHEA, androstenediol, and 7-oxo DHEA stimulated reporter activity. ER antagonists ICI 182,780 (fulvestrant) and 4-hydroxytamoxifen, general P450 inhibitor miconazole, and aromatase inhibitor exemestane inhibited activation by DHEA or metabolites in transfected cells. ERß-selective antagonist R,R-THC (R,R-cis-diethyl tetrahydrochrysene) inhibited DHEA and DHEA metabolite transcriptional activity in ERß-transfected cells. Expression of endogenous estrogen-regulated genes: pS2, progesterone receptor, cathepsin D1, and nuclear respiratory factor-1 was increased by DHEA and its metabolites in an ER-subtype, gene, and cell-specific manner. DHEA metabolites, but not DHEA, competed with 17ß-estradiol for ERα and ERß binding and stimulated MCF-7 cell proliferation, demonstrating that DHEA metabolites interact directly with ERα and ERßin vitro, modulating estrogen target genes in vivo.


Assuntos
Desidroepiandrosterona/análogos & derivados , Desidroepiandrosterona/fisiologia , Receptor alfa de Estrogênio/metabolismo , Receptor beta de Estrogênio/metabolismo , Androstenodiol/farmacologia , Androstenodiona/farmacologia , Animais , Linhagem Celular , Proliferação de Células , Cricetinae , Desidroepiandrosterona/farmacologia , Estradiol/farmacologia , Estradiol/fisiologia , Receptor alfa de Estrogênio/agonistas , Receptor beta de Estrogênio/agonistas , Feminino , Genes Reporter , Humanos , Concentração Inibidora 50 , Luciferases de Renilla/biossíntese , Luciferases de Renilla/genética , Miconazol/farmacologia , Elementos de Resposta , Ativação Transcricional , beta-Galactosidase/biossíntese , beta-Galactosidase/genética
13.
PLoS One ; 8(4): e62334, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23626803

RESUMO

INTRODUCTION: The role of miRNAs in acquired endocrine-resistant breast cancer is not fully understood. One hallmark of tumor progression is epithelial-to-mesenchymal transition (EMT), characterized by a loss of cell adhesion resulting from reduced E-cadherin and increased cell mobility. miR-200 family members regulate EMT by suppressing expression of transcriptional repressors ZEB1/2. Previously we reported that the expression of miR-200a, miR-200b, and miR-200c was lower in LY2 endocrine-resistant, mesenchymal breast cancer cells compared to parental, endocrine sensitive, epithelial MCF-7 breast cancer cells. Here we investigated the regulation of miR-200 family members and their role in endocrine-sensitivity in breast cancer cells. RESULTS: miR-200 family expression was progressively reduced in a breast cancer cell line model of advancing endocrine/tamoxifen (TAM) resistance. Concomitant with miR-200 decrease, there was an increase in ZEB1 mRNA expression. Overexpression of miR-200b or miR-200c in LY2 cells altered cell morphology to a more epithelial appearance and inhibited cell migration. Further, miR-200b and miR-200c overexpression sensitized LY2 cells to growth inhibition by estrogen receptor (ER) antagonists TAM and fulvestrant. Knockdown of ZEB1 in LY2 cells recapitulated the effect of miR-200b and miR-200c overexpression resulting in inhibition of LY2 cell proliferation by TAM and fulvestrant, but not the aromatase inhibitor exemestane. Demethylating agent 5-aza-2'-deoxycytidine (5-aza-dC) in combination with histone deacetylase inhibitor trichostatin A (TSA) increased miR-200b and miR-200c in LY2 cells. Concomitant with the increase in miR-200b and miR-200c, ZEB1 expression was decreased and cells appeared more epithelial in morphology and were sensitized to TAM and fulvestrant inhibition. Likewise, knockdown of ZEB1 increased antiestrogen sensitivity of LY2 cells resulting in inhibition of cell proliferation. CONCLUSIONS: Our data indicate that reduced miRNA-200b and miR-200c expression contributes to endocrine resistance in breast cancer cells and that the reduced expression of these miR-200 family members in endocrine-resistant cells can be reversed by 5-aza-dC+TSA.


Assuntos
Neoplasias da Mama/genética , Resistencia a Medicamentos Antineoplásicos/genética , Expressão Gênica , MicroRNAs/genética , Antineoplásicos Hormonais/farmacologia , Neoplasias da Mama/metabolismo , Caderinas/genética , Caderinas/metabolismo , Linhagem Celular Tumoral , Movimento Celular/genética , Epigênese Genética/efeitos dos fármacos , Transição Epitelial-Mesenquimal/genética , Estradiol/farmacologia , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Técnicas de Silenciamento de Genes , Proteínas de Homeodomínio/genética , Humanos , Hidroxitestosteronas/farmacologia , Células MCF-7 , Fatores de Transcrição/genética , Homeobox 1 de Ligação a E-box em Dedo de Zinco
14.
Gene ; 512(1): 134-42, 2013 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-23026212

RESUMO

Nescient helix-loop-helix-2 (NHLH2) is a basic helix-loop-helix transcription factor, which has been implicated, using mouse knockouts, in adult body weight regulation and fertility. A scan of the known single nucleotide polymorphisms (SNPs) in the NHLH2 gene revealed one in the 3' untranslated region (3'UTR), which lies within an AUUUA RNA stability motif. A second SNP is nonsynonymous within the coding region of NHLH2, and was found in a genome-wide association study for obesity. Both of these SNPs were examined for their effect on NLHL2 by creating mouse mimics and examining mRNA stability, and protein function in mouse hypothalamic cell lines. The 3'UTR SNP causes increased instability and, when the SNP-containing Nhlh2 3'UTR is attached to luciferase mRNA, reduced protein levels in cells. The nonsynonymous SNP at position 83 in the protein changes an alanine residue, conserved in NHLH2 orthologs through the Drosophila sp. to a proline residue. This change affects migration of the protein on an SDS-PAGE gel, and appears to alter secondary structure of the protein, as predicted using in silico methods. These results provide functional information on two rare human SNPs in the NHLH2 gene. One of these has been linked to human obese phenotypes, while the other is present in a relatively high proportion of individuals. Given their effects on NHLH2 protein levels, both SNPs deserve further analysis in whether they are causative and/or additive for human body weight and fertility phenotypes.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Polimorfismo de Nucleotídeo Único , Estabilidade de RNA , RNA Mensageiro/metabolismo , Regiões 3' não Traduzidas , Sequência de Aminoácidos , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/química , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Humanos , Camundongos , Dados de Sequência Molecular , Conformação de Ácido Nucleico , Obesidade/genética , Fases de Leitura Aberta , Filogenia , Conformação Proteica , Domínios e Motivos de Interação entre Proteínas , RNA Mensageiro/química , Alinhamento de Sequência
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