RESUMO
BACKGROUND: Corticosteroid injections (CSI) are commonly used for the treatment of shoulder pain in patients with osteoarthritis (OA) and rotator cuff arthropathy (RCA). These injections may increase the risk of infection following eventual shoulder arthroplasty. PURPOSE: The purpose of this study was to perform a systematic review and meta-analysis of existing data to explore the relationship between preoperative CSI's and postoperative periprosthetic joint infection (PJI) following shoulder arthroplasty. METHODS: A literature search was performed on PubMed, Embase, and Web of Science databases through September 29, 2023. Of the 4,221 retrieved, 7 studies including 136,233 patients were included for qualitative analysis. Studies describing patients receiving CSI prior to shoulder arthroplasty and the effect on postoperative infection risk were included in the systematic review and subsequent meta-analysis. Assessment of risk of bias was performed using the Methodological Index for Non-Randomized Studies (MINORS) criteria. RESULTS: Receiving a corticosteroid injection prior to shoulder arthroplasty was found to have a statistically significant association with increased risk for PJI (OR: 1.13. 95%; CI: 1.06-1.19; p < 0.0001). The rate of PJI increased when injections were given closer to the time of surgery. Patients who received an injection at any time point before surgery had a 5.4% risk of PJI compared to 7.9% and 9.0% in patients receiving an injection within 3 months and 1 month of surgery respectively. This time dependent association however did not reach statistical significance: 1 month OR 1.48; 95% Cl: 0.86-2.53; p = 0.16, 3 months OR 1.95; 95% Cl: 0.95-4.00; p = 0.07. CONCLUSION: The results of this systematic review and meta-analysis demonstrate that patients receiving corticosteroid shoulder injections prior to shoulder arthroplasty may be at an increased risk for prosthetic joint infection postoperatively. While time dependent stratification did not reach statistical significance, our findings indicate a clear trend of increased risk for patients receiving injections closer to surgery.
RESUMO
A dynamic partnership between follicle-stimulating hormone (FSH) and activin is required for normal Sertoli cell development and fertility. Disruptions to this partnership trigger Sertoli cells to deviate from their normal developmental pathway, as observed in inhibin α-knockout (Inha-KO) mice, which feature Sertoli cell tumours in adulthood. Here, we identified the developmental windows by which adult Sertoli cell tumourigenesis is most FSH sensitive. FSH was suppressed for 7 days in Inha-KO mice and wild-type littermates during the 1st, 2nd or 4th week after birth and culled in the 5th week to assess the effect on adult Sertoli cell development. Tumour growth was profoundly reduced in adult Inha-KO mice in response to FSH suppression during Weeks 1 and 2, but not Week 4. Proliferative Sertoli cells were markedly reduced in adult Inha-KO mice following FSH suppression during Weeks 1, 2 or 4, resulting in levels similar to those in wild-type mice, with greatest effect observed at the 2 week time point. Apoptotic Sertoli cells increased in adult Inha-KO mice after FSH suppression during Week 4. In conclusion, acute FSH suppression during the 1st or 2nd week after birth in Inha-KO mice profoundly suppresses Sertoli cell tumour progression, probably by inhibiting proliferation in the adult, with early postnatal Sertoli cells being most sensitive to FSH action.
Assuntos
Inibinas/metabolismo , Tumor de Células de Sertoli/patologia , Espermatogênese/genética , Neoplasias Testiculares/patologia , Ativinas/sangue , Animais , Hormônio Foliculoestimulante/sangue , Inibinas/genética , Masculino , Camundongos , Camundongos Knockout , Tumor de Células de Sertoli/genética , Tumor de Células de Sertoli/metabolismo , Células de Sertoli/metabolismo , Células de Sertoli/patologia , Neoplasias Testiculares/genética , Neoplasias Testiculares/metabolismo , Testículo/metabolismo , Testículo/patologiaRESUMO
The ovarian hormones oestrogen and progesterone profoundly influence breast cancer risk, underpinning the benefit of endocrine therapies in the treatment of breast cancer. Modulation of their effects through ovarian ablation or chemoprevention strategies also significantly decreases breast cancer incidence. Conversely, there is an increased risk of breast cancer associated with pregnancy in the short term. The cellular mechanisms underlying these observations, however, are poorly defined. Here we demonstrate that mouse mammary stem cells (MaSCs) are highly responsive to steroid hormone signalling, despite lacking the oestrogen and progesterone receptors. Ovariectomy markedly diminished MaSC number and outgrowth potential in vivo, whereas MaSC activity increased in mice treated with oestrogen plus progesterone. Notably, even three weeks of treatment with the aromatase inhibitor letrozole was sufficient to reduce the MaSC pool. In contrast, pregnancy led to a transient 11-fold increase in MaSC numbers, probably mediated through paracrine signalling from RANK ligand. The augmented MaSC pool indicates a cellular basis for the short-term increase in breast cancer incidence that accompanies pregnancy. These findings further indicate that breast cancer chemoprevention may be achieved, in part, through suppression of MaSC function.
Assuntos
Estrogênios/metabolismo , Glândulas Mamárias Animais/citologia , Progesterona/metabolismo , Células-Tronco/citologia , Animais , Aromatase/metabolismo , Inibidores da Aromatase/farmacologia , Antígeno CD24/metabolismo , Contagem de Células , Receptores ErbB/metabolismo , Estrogênios/farmacologia , Feminino , Humanos , Integrina beta1/metabolismo , Integrina beta3/metabolismo , Letrozol , Camundongos , Nitrilas/farmacologia , Ovariectomia , Comunicação Parácrina/efeitos dos fármacos , Gravidez , Prenhez/fisiologia , Progesterona/antagonistas & inibidores , Progesterona/farmacologia , Ligante RANK/metabolismo , Receptores de Estrogênio/deficiência , Receptores de Progesterona/deficiência , Transdução de Sinais/efeitos dos fármacos , Células-Tronco/efeitos dos fármacos , Células-Tronco/metabolismo , Triazóis/farmacologiaRESUMO
Although oestrogens are essential for spermatogenesis and their biosynthesis is dependent on aromatase expression, the molecular mechanism of aromatase regulation is poorly understood. Our laboratory has demonstrated that liver kinase B1 (LKB1) is a negative regulator of aromatase in the breast by phosphorylating AMP-activated protein kinase (AMPK) and inhibiting the nuclear translocation of the cAMP response element-binding protein-regulated transcription co-activator (CRTC) 2. The aim of this study was to determine the location of testis-associated proteins in the LKB1-CRTC pathway. Aromatase, LKB1, phosphorylated AMPK (pAMPK) and CRTC1-3 were examined by selected immunofluorescent antibodies in testis samples from a prepubertal boy and three fertile men. Aromatase, pAMPK and LKB1 proteins were present in the seminiferous epithelium and interstitium of the testis and were expressed in a differential and developmental manner in particular cell types. The expression pattern of LKB1 was similar to that of pAMPK and inversely related to aromatase expression. CRTC1 and CRTC3 were localised in the seminiferous epithelium, whereas CRTC2 was barely detectable in testis. These results lead to the conclusion that LKB1 is involved in the molecular pathway that underpins aromatase regulation in the testis via CRTC1 and CRTC3 and may be important for the oestrogen-mediated development of germ cells.
RESUMO
Unintended pregnancy is an important public health problem worldwide. Unwanted pregnancies may end in induced abortion (legal or illegal, safe or unsafe) or in childbirth. In many parts of the world both can be life threatening. Even where both are safe, abortion is distressing for all concerned while unwanted births often lead to poor health and social outcomes for both the mother and her child.
Assuntos
Anticoncepção Pós-Coito/métodos , Anticoncepcionais , Levanogestrel , Norpregnadienos , Sociedades Médicas/normas , Anticoncepção Pós-Coito/normas , Anticoncepcionais/administração & dosagem , Anticoncepcionais/efeitos adversos , Anticoncepcionais/farmacologia , Feminino , Humanos , Levanogestrel/administração & dosagem , Levanogestrel/efeitos adversos , Levanogestrel/farmacologia , Norpregnadienos/administração & dosagem , Norpregnadienos/efeitos adversos , Norpregnadienos/farmacologiaRESUMO
Purpose: To assess the diagnostic capability of radiographs (XRs) to detect pincer lesions compared with 3-dimensional (3D) computed tomography scans in patients undergoing hip arthroscopy for femoroacetabular impingement syndrome (FAIS). Methods: We performed a retrospective review of all patients who underwent hip arthroscopy for FAIS between September 1, 2020, and October 2, 2022. Preoperative imaging was reviewed. Pincer lesions were defined as a lateral center-edge angle greater than 40°; a Tönnis angle greater than 0°; the presence of the ischial spine, crossover, or posterior wall sign; and the presence of overcoverage greater than 80%. Under "select criteria," patients were classified as having a pincer lesion on XRs and 3D computed tomography reconstructions (CTRs) based on the lateral center-edge angle or Tönnis angle alone, whereas "all criteria" added the presence of the crossover sign and coverage percentage. Statistical analysis was performed to determine the diagnostic accuracy of XRs compared with 3D CTRs. Results: A total of 69 patients met the inclusion criteria. There were 21 male patients (30.4%) and 48 female patients (69.6%). The mean age was 33 ± 13.5 years. χ2 Analysis for select criteria found that 3D CTR was more likely than XRs to detect a pincer lesion. χ2 Analysis for all criteria found that 3D CTR was more likely than XRs to detect a pincer lesion. χ2 Analysis further showed that when using XRs, a pincer lesion was more likely to be detected under all criteria than under select criteria. Likewise, when using 3D CTR, a pincer lesion was more likely to be detected under all criteria than under select criteria. Conclusions: In this study, we found that 3D CTR detected pincer lesions in patients undergoing hip arthroscopy for FAIS with significantly higher sensitivity than XRs alone. Level of Evidence: Level III, retrospective cohort study.
RESUMO
Background: The BONEBRIDGE® (Med-El GmbH) is a bone-conduction device comprising an external audio processor and an internal Bone Conduction-Floating Mass Transducer (BC-FMT) surgically anchored to the temporal bone. Due to the implant's size, its placement may be challenging in certain anatomies, necessitating thorough surgical planning. Manual planning methods are laborious, time-intensive, and prone to errors. This study aimed to develop and validate an automated algorithm for determining skull thickness, aiding in the surgical planning of the BONEBRIDGE and other devices requiring similar bone thickness estimations. Materials and methods: Twelve cadaveric temporal bones underwent clinical computed tomography (CT). A custom Python algorithm was developed to automatically segment bone from soft tissue, generate 3D models, and perform ray-tracing to estimate bone thickness. Two thickness colormaps were generated for each sample: the cortical thickness to the first air cell and the total thickness down to the dura. The algorithm was validated against expert manual measurements to achieve consensus interpretation. Results: The algorithm estimated bone-to-air thicknesses (mean = 4.7 mm, 95% Confidence Interval [CI] of 4.3-5.0 mm) that closely matched the expert measurements (mean = 4.7 mm, CI of 4.4-5.0 mm), with a mean absolute difference (MAD) of 0.3 mm. Similarly, the algorithm's estimations to the dura (6.0 mm, CI of 5.4-6.5 mm) were comparable to the expert markings (5.9 mm, CI of 5.4-6.5 mm), with a MAD of 0.3 mm. Conclusions: The first automated algorithm to calculate skull thickness to both the air cells and dura in the temporal bone was developed. Colormaps were optimized to aid with the surgical planning of BONEBRIDGE implantation, however the tool can be generalized to aid in the surgical planning of any bone thickness application. The tool was published as a freely available extension to the open-source 3D Slicer software program (www.slicer.org).
RESUMO
INTRODUCTION: The majority of postmenopausal breast cancers are estrogen-dependent. Tumor-derived factors, such as prostaglandin E2 (PGE2), stimulate CREB1 binding to cAMP response elements (CREs) on aromatase promoter II (PII), leading to the increased expression of aromatase and biosynthesis of estrogens within human breast adipose stromal cells (ASCs). Hypoxia inducible factor-1α (HIF-1α), a key mediator of cellular adaptation to low oxygen levels, is emerging as a novel prognostic marker in breast cancer. We have identified the presence of a consensus HIF-1α binding motif overlapping with the proximal CRE of aromatase PII. However, the regulation of aromatase expression by HIF-1α in breast cancer has not been characterized. This study aimed to characterize the role of HIF-1α in the activation of aromatase PII. METHODS: HIF-1α expression and localization were examined in human breast ASCs using quantitative PCR (QPCR), Western blotting, immunofluorescence and high content screening. QPCR and tritiated water-release assays were performed to assess the effect of HIF-1α on aromatase expression and activity. Reporter assays and chromatin immunoprecipitation (ChIP) were performed to assess the effect of HIF-1α on PII activity and binding. Treatments included PGE2 or DMOG ((dimethyloxalglycine), HIF-1α stabilizer). Double immunohistochemistry for HIF-1α and aromatase was performed on tissues obtained from breast cancer and cancer-free patients. RESULTS: Results indicate that PGE2 increases HIF-1α transcript and protein expression, nuclear localization and binding to aromatase PII in human breast ASCs. Results also demonstrate that HIF-1α significantly increases PII activity, and aromatase transcript expression and activity, in the presence of DMOG and/or PGE2, and that HIF-1α and CREB1 act co-operatively on PII. There is a significant increase in HIF-1α positive ASCs in breast cancer patients compared to cancer-free women, and a positive association between HIF-1α and aromatase expression. CONCLUSIONS: This study is the first to identify HIF-1α as a modulator of PII-driven aromatase expression in human breast tumor-associated stroma and provides a novel mechanism for estrogen regulation in obesity-related, post-menopausal breast cancer. Together with our on-going studies on the role of AMP-activated protein kinase (AMPK) in the regulation of breast aromatase, this work provides another link between disregulated metabolism and breast cancer.
Assuntos
Tecido Adiposo/metabolismo , Aromatase/genética , Neoplasias da Mama/metabolismo , Dinoprostona/farmacologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Células Estromais/metabolismo , Tecido Adiposo/efeitos dos fármacos , Tecido Adiposo/patologia , Aromatase/metabolismo , Western Blotting , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Carcinoma Ductal de Mama/tratamento farmacológico , Carcinoma Ductal de Mama/metabolismo , Carcinoma Ductal de Mama/patologia , Núcleo Celular/efeitos dos fármacos , Núcleo Celular/metabolismo , Imunoprecipitação da Cromatina , Feminino , Imunofluorescência , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Técnicas Imunoenzimáticas , Ocitócicos/farmacologia , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Células Estromais/efeitos dos fármacos , Células Estromais/patologia , Células Tumorais CultivadasRESUMO
Expression of the oestrogen producing enzyme, aromatase, is regulated in a tissue-specific manner by its encoding gene CYP19A1. In post-menopausal women, the major site for oestrogen production in the breast is the adipose, where CYP19A1 transcription is driven by the distal promoter I.4 (PI.4). Transcripts via this promoter are also elevated in breast adipose fibroblasts (BAFs) adjacent to a tumour. PI.4 expression is stimulated by a number of cytokines, and TNFα is one such factor. The transcriptional mechanisms induced by TNFα to stimulate PI.4 are poorly characterised. We show that the early growth response (Egr) transcription factors play an important role in the TNFα-induced signalling pathway resulting in elevated PI.4 transcription. TNFα treatment of BAFs increases mRNA levels of all four Egr family members, with EGR2 being the most highly expressed. Overexpression of EGR2 causes an increase in endogenous CYP19A1 expression in preadipocyte Simpson-Golabi-Behmel syndrome cells, driven by increases in PI.4-specific transcripts. PI.4 luciferase reporter activity is increased in a dose-dependent manner by EGR2, EGR3 and EGR4, with EGR2 showing the most potent activation of promoter activity. Deletion analysis indicates that this promoter activity is being indirectly mediated by a short region of the promoter not containing any previously characterised binding sites, and we further show that EGR2 does not bind directly or indirectly to this promoter region. However, siRNA knockdown of the Egrs reduces the total and PI.4-derived CYP19A1 transcription in BAFs. These studies unveil a novel component of the aromatase gene regulatory network and further enhance the complexity of oestrogen production in the breast.
Assuntos
Tecido Adiposo/efeitos dos fármacos , Tecido Adiposo/metabolismo , Aromatase/genética , Mama/citologia , Fatores de Transcrição de Resposta de Crescimento Precoce/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Fator de Necrose Tumoral alfa/farmacologia , Animais , Linhagem Celular , Proteína 2 de Resposta de Crescimento Precoce/genética , Proteína 2 de Resposta de Crescimento Precoce/metabolismo , Fatores de Transcrição de Resposta de Crescimento Precoce/genética , Feminino , Expressão Gênica , Genes Reporter , Humanos , Regiões Promotoras Genéticas , Ligação Proteica , Interferência de RNA , RNA Mensageiro/genética , Elementos de Resposta , Deleção de Sequência , Ativação TranscricionalRESUMO
The interaction between breast tumor epithelial and stromal cells is vital for initial and recurrent tumor growth. While breast cancer-associated stromal cells provide a favorable environment for proliferation and metastasis, the molecular mechanisms contributing to this process are not fully understood. Nuclear receptors (NRs) are intracellular transcription factors that directly regulate gene expression. Little is known about the status of NRs in cancer-associated stroma. Nuclear Receptor Low-Density Taqman Arrays were used to compare the gene expression profiles of all 48 NR family members in a collection of primary cultured cancer-associated fibroblasts (CAFs) obtained from estrogen receptor (ER)α positive breast cancers (n = 9) and normal breast adipose fibroblasts (NAFs) (n = 7). Thirty-three of 48 NRs were expressed in both the groups, while 11 NRs were not detected in either. Three NRs (dosage-sensitive sex reversal, adrenal hypoplasia critical region, on chromosome X, gene 1 (DAX-1); estrogen-related receptor beta (ERR-ß); and RAR-related orphan receptor beta (ROR-ß)) were only detected in NAFs, while one NR (liver receptor homolog-1 (LRH-1)) was unique to CAFs. Of the NRs co-expressed, four were significantly down-regulated in CAFs compared with NAFs (RAR-related orphan receptor-α (ROR-α); Thyroid hormone receptor-ß (TR-ß); vitamin D receptor (VDR); and peroxisome proliferator-activated receptor-γ (PPAR-γ)). Quantitative immunohistochemistry for LRH-1, TR-ß, and PPAR-γ proteins in stromal fibroblasts from an independent panel of breast cancers (ER-positive (n = 15), ER-negative (n = 15), normal (n = 14)) positively correlated with mRNA expression profiles. The differentially expressed NRs identified in tumor stroma are key mediators in aromatase regulation and subsequent estrogen production. Our findings reveal a distinct pattern of NR expression that therefore fits with a sustained and increased local estrogen microenvironment in ER-positive tumors. NRs in CAFs may provide a new avenue for the development of intratumoral-targeted therapies in breast cancer.
Assuntos
Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Receptores Citoplasmáticos e Nucleares/metabolismo , Células Estromais/metabolismo , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/genética , Feminino , Expressão Gênica , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Imuno-Histoquímica , Pessoa de Meia-Idade , Gradação de Tumores , Receptor ErbB-2/metabolismo , Receptores Citoplasmáticos e Nucleares/genética , Receptores de Estrogênio/metabolismo , Receptores de Progesterona/metabolismo , Fatores de RiscoRESUMO
The present study aims to determine the estrogenicity of Millettia macrophylla, a Cameroonian medicinal plant, in ovariectomized rats and to investigate the underlying mechanisms, in order to justify scientifically its traditional use. To accomplish this objective, we used dichloromethane (DCM) and methanol (MeOH) extracts of the stem bark of M. macrophylla. In the cell culture based assay, the MeOH extract significantly transactivated estrogen receptor α (ERα) and estrogen receptor ß (ERß); in addition, the estrogen-like effects of both, DCM and MeOH extracts, could be inhibited in vitro by the pure ER antagonist ICI 182,780, indicating that these effects were primarily mediated through ERs. In animal experiments, both DCM and MeOH extracts significantly increased the uterine and vaginal epithelial heights in the 3-day treatment assay, while only the MeOH extract exhibited such effects in the sub-chronic treatment regimen. Furthermore, the MeOH extract significantly decreased fasting serum triglycerides, total cholesterol levels and artherogenic risk in the sub-chronic treatment. These results indicate that M. macrophylla extracts have estrogen-like effects supporting their traditional use in Cameroon to alleviate some menopausal problems (See graphical abstract in Supplementary Fig. 1, available in the online version only).
Assuntos
Receptor alfa de Estrogênio/genética , Receptor beta de Estrogênio/genética , Millettia , Fitoestrógenos , Extratos Vegetais/farmacologia , Ativação Transcricional/efeitos dos fármacos , Animais , Células Cultivadas , Epitélio/efeitos dos fármacos , Estradiol/análogos & derivados , Estradiol/farmacologia , Antagonistas de Estrogênios/farmacologia , Receptor alfa de Estrogênio/metabolismo , Receptor beta de Estrogênio/metabolismo , Feminino , Fulvestranto , Células HEK293 , Humanos , Metanol , Cloreto de Metileno , Ovariectomia , Extratos Vegetais/antagonistas & inibidores , Caules de Planta , Ratos , Ratos Wistar , Útero/efeitos dos fármacos , Vagina/efeitos dos fármacosRESUMO
The aim of this study was to create a comprehensive mouse model of the metabolic syndrome by crossing aromatase-deficient (ArKO) mice with apolipoprotein E-deficient (ApoE(-/-)) mice. Successive crossbreeding of ArKO with ApoE(-/-)-deficient mice generated double knockout, MetS-Tg mice. The phenotypic characteristics of the MetS-Tg mice were assessed at 3, 6, and 12 mo of age and compared with age- and sex-matched wild-type (WT) controls. Blood pressure and heart rate were recorded by a noninvasive, computerized tail-cuff system. Oral glucose and intraperitoneal insulin tolerance tests were performed. Serum cholesterol levels were measured by a combined quantitative colorimetric assay. Plasma adiponectin, C-reactive protein (CRP), insulin, interleukin-6 (IL-6), leptin, resistin, and tumor necrosis factor-α (TNF-α) were measured by multiplexed ELISA. MetS-Tg mice displayed significantly increased body weight, central obesity, and elevated blood pressure at all three ages compared with WT mice. Elevated serum cholesterol was associated with higher triglycerides and LDL/VLDL cholesterol particles and was accompanied by a decrease in HDL and histological evidence of fatty liver. MetS-Tg mice of all ages showed impaired glucose tolerance. At 12 mo, MetS-Tg mice had elevated plasma levels of CRP, IL-6, leptin, and TNF-α, but resistin levels were largely unchanged. We now report that this combination of gene knockouts produces a novel strain of mice that display the diverse clinical features of the metabolic syndrome, including central obesity, progressive hypertension, an adverse serum lipid profile, fatty liver, glucose intolerance, insulin resistance, and evidence of an inflammatory state.
Assuntos
Apolipoproteínas E/fisiologia , Aromatase/fisiologia , Modelos Animais de Doenças , Síndrome Metabólica/fisiopatologia , Tecido Adiposo Branco/imunologia , Tecido Adiposo Branco/patologia , Animais , Aorta/imunologia , Aorta/patologia , Apolipoproteínas E/genética , Aromatase/genética , Aterosclerose/etiologia , Proteína C-Reativa/análise , Cruzamentos Genéticos , Citocinas/sangue , Fígado Gorduroso/etiologia , Feminino , Intolerância à Glucose/etiologia , Hiperlipidemias/etiologia , Hipertensão/etiologia , Resistência à Insulina , Fígado/imunologia , Fígado/patologia , Masculino , Síndrome Metabólica/sangue , Síndrome Metabólica/imunologia , Síndrome Metabólica/patologia , Camundongos , Camundongos Knockout , Obesidade Abdominal/etiologiaRESUMO
The main biological active substance secreted by the pineal gland, melatonin (MLT), counteracts the effects of estrogens in breast cancer via exerting a number of its own oncostatic properties. Recent studies of postmenopausal women have identified that the major metabolite of MLT is statistically significantly associated with a lower risk of developing breast cancer. While MLT production decreases with age, breast cancer risk, however, increases with age and obesity. We hypothesize that MLT inhibits estrogen production in breast adipose fibroblasts (BAFs), the main local source of estrogen in breast tumors of postmenopausal women, by inhibiting transcription of the CYP19A1 gene that encodes the key enzyme aromatase. Normal BAFs were cultured from women undergoing breast reduction surgery, while breast cancer-associated fibroblasts (CAFs) were isolated from three women with estrogen receptor (ER) positive invasive ductal carcinomas. MTNR1A and MTNR1B receptor expression and CYP19A1 mRNA expression following MLT treatments were determined by qRT-PCR. BAFs express the G-protein coupled MLT receptors MTNR1A and MTNR1B with elevated levels of MTNR1A found in CAFs. Treatment of BAFs and CAFs with MLT resulted in significant suppression of CYP19A1 transcription and aromatase activity at pharmacological, physiological and sub-physiological concentrations. MLT suppression occurred through promoter-specific PI.4-, PI.3- and PII-derived CYP19A1 mRNA. Stimulation of CYP19A1 PII-mRNA and aromatase activity by prostaglandin E(2) (PGE(2)) were significantly attenuated by physiological doses of MLT. Lower levels of MLT in aging women may increase the risk of progressing ER-positive breast cancer through a decreased ability to suppress CYP19A1 expression and subsequent local estrogen production in BAFs/CAFs.
Assuntos
Tecido Adiposo/enzimologia , Aromatase/metabolismo , Neoplasias da Mama/enzimologia , Carcinoma Ductal de Mama/enzimologia , Fibroblastos/enzimologia , Melatonina/metabolismo , Tecido Adiposo/patologia , Aromatase/genética , Neoplasias da Mama/patologia , Carcinoma Ductal de Mama/patologia , Células Cultivadas , Dinoprostona/metabolismo , Regulação para Baixo , Feminino , Fibroblastos/patologia , Regulação Enzimológica da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Reação em Cadeia da Polimerase , Regiões Promotoras Genéticas , RNA Mensageiro/metabolismo , Receptor MT1 de Melatonina/metabolismo , Receptor MT2 de Melatonina/metabolismo , Receptores de Estrogênio/metabolismo , Transcrição GênicaRESUMO
Aromatase converts androgens to estrogens and it is expressed in gonads and non-reproductive tissues (e.g. brain and adipose tissues). As circulating levels of estrogens in males are low, we hypothesize that local estrogen production is important for the regulation of physiological functions (e.g. metabolism) and pathological development (e.g. breast and prostate cancers) by acting in a paracrine and/or intracrine manner. We generated a tissue-specific doxycycline-inducible, aromatase transgenic mouse to test this hypothesis. The transgene construct (pTetOAROM) consists of a full-length human aromatase cDNA (hAROM) and a luciferase gene under the control of a bi-directional tetracycline-responsive promoter (pTetO), which is regulated by transactivators (rtTA or tTA) and doxycycline. Our in vitro studies using MBA-MB-231tet cells stably expressing rtTA, showed that doxycycline treatment induced transgene expression of hAROM transcripts by 17-fold (P = 0.01), aromatase activity by 26-fold, (P = 0.0008) and luciferase activity by 9.6-fold (P = 0.0006). Pronuclear microinjection of the transgene generated four pTetOAROM founder mice. A male founder was bred with a female mammary gland-specific rtTA mouse (MMTVrtTA) to produce MMTVrtTA-pTetOAROM double-transgenic mice. Upon doxycycline treatment via drinking water, human aromatase expression was detected by RT-PCR, specifically in mammary glands, salivary glands and seminal vesicles of double-stransgenic mice. Luciferase expression and activity was detected in these tissues by in vivo bioluminescence imaging, in vitro luciferase assay and RT-PCR. In summary, we generated a transgenic mouse model that expresses the human aromatase transgene in a temporal- and spatial-specific manner, which will be a useful model to study the physiological importance of local estrogen production.
Assuntos
Aromatase/metabolismo , Doxiciclina/farmacologia , Regulação Enzimológica da Expressão Gênica , Animais , Aromatase/genética , Linhagem Celular Tumoral , Clonagem Molecular , DNA Complementar/genética , DNA Complementar/metabolismo , Doxiciclina/administração & dosagem , Ativação Enzimática , Ensaios Enzimáticos , Feminino , Vetores Genéticos/genética , Vetores Genéticos/metabolismo , Humanos , Luciferases de Vaga-Lume/genética , Luciferases de Vaga-Lume/metabolismo , Medições Luminescentes/métodos , Masculino , Glândulas Mamárias Humanas/citologia , Glândulas Mamárias Humanas/metabolismo , Camundongos , Camundongos Transgênicos , Microinjeções , Plasmídeos/genética , Plasmídeos/metabolismo , Regiões Promotoras Genéticas , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Glândulas Salivares/citologia , Glândulas Salivares/metabolismo , Glândulas Seminais/citologia , Glândulas Seminais/metabolismo , TransgenesRESUMO
Inspired by the localization, on 15q21.2 of the CYP19A1 gene in the linkage region of speech and language disorders, and a rare translocation in a dyslexic individual that was brought to our attention, we conducted a series of studies on the properties of CYP19A1 as a candidate gene for dyslexia and related conditions. The aromatase enzyme is a member of the cytochrome P450 super family, and it serves several key functions: it catalyzes the conversion of androgens into estrogens; during early mammalian development it controls the differentiation of specific brain areas (e.g. local estrogen synthesis in the hippocampus regulates synaptic plasticity and axonal growth); it is involved in sexual differentiation of the brain; and in songbirds and teleost fishes, it regulates vocalization. Our results suggest that variations in CYP19A1 are associated with dyslexia as a categorical trait and with quantitative measures of language and speech, such as reading, vocabulary, phonological processing and oral motor skills. Variations near the vicinity of its brain promoter region altered transcription factor binding, suggesting a regulatory role in CYP19A1 expression. CYP19A1 expression in human brain correlated with the expression of dyslexia susceptibility genes such as DYX1C1 and ROBO1. Aromatase-deficient mice displayed increased cortical neuronal density and occasional cortical heterotopias, also observed in Robo1-/- mice and human dyslexic brains, respectively. An aromatase inhibitor reduced dendritic growth in cultured rat neurons. From this broad set of evidence, we propose CYP19A1 as a candidate gene for human cognitive functions implicated in reading, speech and language.
Assuntos
Aromatase/genética , Encéfalo/crescimento & desenvolvimento , Dislexia/genética , Transtornos da Linguagem/genética , RNA Mensageiro/análise , Distúrbios da Fala/genética , Animais , Aromatase/metabolismo , Encéfalo/metabolismo , Encéfalo/patologia , Estudos de Coortes , Proteínas do Citoesqueleto , Dislexia/metabolismo , Feminino , Regulação da Expressão Gênica , Predisposição Genética para Doença , Humanos , Transtornos da Linguagem/metabolismo , Masculino , Camundongos , Camundongos Knockout , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Polimorfismo de Nucleotídeo Único , Regiões Promotoras Genéticas , Locos de Características Quantitativas , Receptores Imunológicos/genética , Receptores Imunológicos/metabolismo , Distúrbios da Fala/metabolismo , Translocação Genética , Proteínas RoundaboutRESUMO
BACKGROUND: Currently available live, oral rotavirus vaccines (LORVs) have significantly reduced severe rotavirus hospitalizations and deaths worldwide. However, LORVs are not as effective in low- and middle-income countries (LMIC) where rotavirus disease burden is highest. Next-generation rotavirus vaccine (NGRV) candidates in development may have a greater public health impact where they are needed most. The feasibility and acceptability of possible new rotavirus vaccines were explored as part of a larger public health value proposition for injectable NGRVs in LMICs. OBJECTIVE: To assess national stakeholder preferences for currently available LORVs and hypothetical NGRVs and understand rationales and drivers for stated preferences. METHODS: Interviews were conducted with 71 national stakeholders who influence vaccine policy and national programming. Stakeholders from Ghana, Kenya, Malawi, Peru, Senegal, and Sri Lanka were interviewed using a mixed-method guide. Vaccine preferences were elicited on seven vaccine comparisons involving LORVs and hypothetical NGRVs based on information presented comparing the vaccines' attributes. Reasons for vaccine preference were elicited in open-ended questions, and the qualitative data were analyzed on key preference drivers. RESULTS: Nearly half of the national stakeholders interviewed preferred a highly effective standalone, injectable NGRV over current LORVs. When presented as having similar efficacy to the LORV, however, very few stakeholders preferred the injectable NGRV, even at substantially lower cost. Similarly, a highly effective standalone injectable NGRV was generally not favored over an equally effective oral NGRV following a neonatal-infant schedule, despite higher cost of the neonatal option. An NGRV-DTP-containing combination vaccine was strongly preferred over all other options, whether delivered alone with efficacy similar to current LORVs or co-administered alongside an LORV (LORV + NGRV-DTP) to increase efficacy. CONCLUSION: Results from these national stakeholder interviews provide valuable insights to inform ongoing and future NGRV research and development.
Assuntos
Infecções por Rotavirus , Vacinas contra Rotavirus , Rotavirus , Hospitalização , Humanos , Lactente , Recém-Nascido , Pobreza , Infecções por Rotavirus/prevenção & controleRESUMO
BACKGROUND: Live oral rotavirus vaccines (LORVs) have significantly reduced rotavirus hospitalizations and deaths worldwide. However, LORVs are less effective in low- and middle-income countries (LMICs). Next-generation rotavirus vaccines (NGRVs) may be more effective but require administration by injection or a neonatal oral dose, adding operational complexity. Healthcare providers (HPs) were interviewed to assess rotavirus vaccine preferences and identify delivery issues as part of an NGRV value proposition. OBJECTIVE: Determine HP vaccine preferences about delivering LORVs compared to injectable (iNGRV) and neonatal oral (oNGRV) NGRVs. METHODS: 64 HPs from Ghana, Kenya, Malawi, Peru, and Senegal were interviewed following a mixed-method guide centered on three vaccine comparisons: LORV vs. iNGRV; LORV vs. oNGRV; oNGRV vs. iNGRV. HPs reviewed attributes for each vaccine in the comparisons, then indicated and explained their preference. Additional questions elicited views about co-administering iNGRV+LORV for greater public health impact, a possible iNGRV-DTP-containing combination vaccine, and delivering neonatal doses. RESULTS: Almost all HPs preferred oral vaccine options over iNGRV, with many emphasizing an aversion to additional injections. Despite this strong preference, HPs described challenges delivering oral doses. Preferences for LORV vs. oNGRV were split, marked by disparate views on rotavirus disease epidemiology and the safety, need, and feasibility of delivering neonatal vaccines. Although overwhelmingly enthusiastic about an iNGRV-DTP-containing combination option, several HPs had concerns. HP views were divided on the feasibility of co-administering iNGRV+LORV, citing challenges around logistics and caregiver sensitization. CONCLUSION: Our findings provide valuable insights on delivering NGRVs in routine immunization. Despite opposition to injectables, openness to co-administering LORV+iNGRV to improve efficacy suggests future HP support of iNGRV if adequately informed of its advantages. Rationales for LORV vs. oNGRV underscore needs for training on rotavirus epidemiology and stronger service integration. Expressed challenges delivering existing LORVs merit further examination and indicate need for improved delivery.
Assuntos
Infecções por Rotavirus , Vacinas contra Rotavirus , Rotavirus , Países em Desenvolvimento , Pessoal de Saúde , Humanos , Lactente , Recém-Nascido , Infecções por Rotavirus/epidemiologiaRESUMO
The hormone estradiol affects the auditory system both by itself and by its interaction with neuroprotective factors. In this study, we examined the role of estrogen receptors (ERs) in response to auditory trauma. We found a ligand-dependent protective role for ERbeta in the auditory system by investigating mice deficient in ERalpha (ERKO mice), ERbeta (BERKO mice), and aromatase (ARKO mice). Basal auditory brainstem response (ABR) thresholds were similar in all animals. An acoustic trauma causing a temporary hearing loss raised ABR thresholds in male and female BERKO and ARKO mice compared with WT and ERKO mice. The ERalpha-selective agonist, propyl(1H) pyrazole-1,3,5-triyl-trisphenol (PPT), partially protected ARKO mice from trauma, while the ERbeta-selective agonist, 2,3-bis (4-hydroxyphenyl)-propionitrile (DPN), protected WT and ARKO mice. Immunohistochemistry and western blotting confirmed the expression of ERbeta in cochlea of WT males and females. Levels of brain-derived neurotrophic factor (BDNF), a neuroprotective peptide that can be induced by estrogen, was lower in BERKO and ARKO mice compared with WT. DPN treatment increased BDNF expression in ARKO mice. These data indicate ERbeta-mediated neuroprotection involving BDNF in the auditory system of males and females.
Assuntos
Receptor beta de Estrogênio/metabolismo , Perda Auditiva Provocada por Ruído/metabolismo , Animais , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Cóclea/metabolismo , Receptor alfa de Estrogênio/agonistas , Receptor alfa de Estrogênio/deficiência , Receptor alfa de Estrogênio/genética , Receptor alfa de Estrogênio/metabolismo , Receptor beta de Estrogênio/agonistas , Receptor beta de Estrogênio/deficiência , Receptor beta de Estrogênio/genética , Feminino , Perda Auditiva Provocada por Ruído/tratamento farmacológico , Perda Auditiva Provocada por Ruído/genética , Perda Auditiva Provocada por Ruído/patologia , Imuno-Histoquímica , Masculino , Camundongos , Camundongos Knockout , Nitrilas/uso terapêuticoRESUMO
AMP-activated protein kinase (AMPK) is recognized as a master regulator of energy homeostasis. In concert with the AMPK-kinase LKB1, it has been shown to provide a molecular link between obesity and postmenopausal breast cancer via its actions to inhibit aromatase expression, hence estrogen production, within the breast. The anti-diabetic drug metformin is known to increase the activity of AMPK and was therefore hypothesized to inhibit aromatase expression in primary human breast adipose stromal cells. Results demonstrate that metformin significantly decreases the forskolin/phorbol ester (FSK/PMA)-induced expression of aromatase at concentrations of 10 and 50 muM. Consistent with the hypothesized actions of metformin to increase AMPK activity, treatment with 50 muM metformin results in a significant increase in phosphorylation of AMPK at Thr172. Interestingly, metformin also causes a significant increase in LKB1 protein expression and promoter activity, thereby providing for the first time an additional mechanism by which metformin activates AMPK. Furthermore, metformin inhibits the nuclear translocation of CRTC2, a CREB-coactivator known to increase aromatase expression which is also a direct downstream target of AMPK. Overall, these results suggest that metformin would reduce the local production of estrogens within the breast thereby providing a new key therapeutic tool that could be used in the neoadjuvant and adjuvant settings and conceivably also as a preventative measure in obese women.
Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Tecido Adiposo/efeitos dos fármacos , Inibidores da Aromatase/farmacologia , Aromatase/metabolismo , Mama/efeitos dos fármacos , Metformina/farmacologia , Células Estromais/efeitos dos fármacos , Quinases Proteína-Quinases Ativadas por AMP , Transporte Ativo do Núcleo Celular , Tecido Adiposo/enzimologia , Animais , Aromatase/genética , Sítios de Ligação , Mama/enzimologia , Células COS , Chlorocebus aethiops , Colforsina/farmacologia , Relação Dose-Resposta a Droga , Ativação Enzimática , Feminino , Humanos , Fosforilação , Regiões Promotoras Genéticas , Proteínas Serina-Treonina Quinases/metabolismo , Células Estromais/enzimologia , Acetato de Tetradecanoilforbol/farmacologia , Treonina , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , TransfecçãoRESUMO
1. Oestrogen plays an important role in ageing and ageing-related development. Lack of oestrogen prompts endocrine cell ageing of the ovary, whereas oestrogen overflow impacts on epithelial cell neoplastic development. 2. Recent studies indicate that oestrogen regulates cell proliferative fates by a mechanism of reprogramming the size of telomeres (ends of chromosomes) in the oestrogen target cells. This is achieved by upregulating the telomerase reverse transcriptase (TERT) gene in a temporal and spatial manner. 3. Currently, the relationship between oestrogen and telomerase activity in regulating productive cell development and function remains elusive. A number of lines of evidence suggest that telomerase is a downstream target of oestrogen in oestrogen-dependent reproductive ageing and neoplastic development. 4. The present minireview discusses our current understanding of the mechanisms by which telomerase maintenance of telomere homeostasis mediates oestrogen-induced ageing and tumourigenesis in the ovary under physiological and pathological conditions.