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1.
Circulation ; 143(2): 135-144, 2021 01 12.
Artigo em Inglês | MEDLINE | ID: mdl-33200947

RESUMO

BACKGROUND: Obesity may contribute to adverse outcomes in coronavirus disease 2019 (COVID-19). However, studies of large, broadly generalizable patient populations are lacking, and the effect of body mass index (BMI) on COVID-19 outcomes- particularly in younger adults-remains uncertain. METHODS: We analyzed data from patients hospitalized with COVID-19 at 88 US hospitals enrolled in the American Heart Association's COVID-19 Cardiovascular Disease Registry with data collection through July 22, 2020. BMI was stratified by World Health Organization obesity class, with normal weight prespecified as the reference group. RESULTS: Obesity, and, in particular, class III obesity, was overrepresented in the registry in comparison with the US population, with the largest differences among adults ≤50 years. Among 7606 patients, in-hospital death or mechanical ventilation occurred in 2109 (27.7%), in-hospital death in 1302 (17.1%), and mechanical ventilation in 1602 (21.1%). After multivariable adjustment, classes I to III obesity were associated with higher risks of in-hospital death or mechanical ventilation (odds ratio, 1.28 [95% CI, 1.09-1.51], 1.57 [1.29-1.91], 1.80 [1.47-2.20], respectively), and class III obesity was associated with a higher risk of in-hospital death (hazard ratio, 1.26 [95% CI, 1.00-1.58]). Overweight and class I to III obese individuals were at higher risk for mechanical ventilation (odds ratio, 1.28 [95% CI, 1.09-1.51], 1.54 [1.29-1.84], 1.88 [1.52-2.32], and 2.08 [1.68-2.58], respectively). Significant BMI by age interactions were seen for all primary end points (P-interaction<0.05 for each), such that the association of BMI with death or mechanical ventilation was strongest in adults ≤50 years, intermediate in adults 51 to 70 years, and weakest in adults >70 years. Severe obesity (BMI ≥40 kg/m2) was associated with an increased risk of in-hospital death only in those ≤50 years (hazard ratio, 1.36 [1.01-1.84]). In adjusted analyses, higher BMI was associated with dialysis initiation and with venous thromboembolism but not with major adverse cardiac events. CONCLUSIONS: Obese patients are more likely to be hospitalized with COVID-19, and are at higher risk of in-hospital death or mechanical ventilation, in particular, if young (age ≤50 years). Obese patients are also at higher risk for venous thromboembolism and dialysis. These observations support clear public health messaging and rigorous adherence to COVID-19 prevention strategies in all obese individuals regardless of age.


Assuntos
Índice de Massa Corporal , COVID-19 , Hospitalização , Obesidade , Sistema de Registros , SARS-CoV-2 , Fatores Etários , Idoso , American Heart Association , COVID-19/mortalidade , COVID-19/terapia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Obesidade/classificação , Obesidade/mortalidade , Obesidade/terapia , Estados Unidos/epidemiologia
2.
J Am Pharm Assoc (2003) ; 60(3): 485-490, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31901441

RESUMO

OBJECTIVE: The aim of this study was to analyze the effect of clinical pharmacy services on health outcomes and medication adherence concerning hypertension and diabetes in the homeless population. METHODS: This was a retrospective quasi-experimental study conducted between January 1, 2015, and December 31, 2016. The primary outcomes included median blood pressure and median glycosylated hemoglobin (A1C) change from baseline. The secondary end points included adherence to hypertension and diabetes medication, in addition to the differences in the number of admissions to urgent care clinics, emergency departments, or hospitals pre- and postpharmacist clinic visit. RESULTS: One-hundred ninety-eight homeless patients were seen by a pharmacist over the study time frame, and 116 of these patients were included. There was a decrease in systolic and diastolic blood pressure in the 6-months postpharmacist visit (139 mm Hg vs. 135 mm Hg, P = 0.413, and 85 mm Hg vs. 82 mm Hg, P = 0.197, respectively). The percentage of patients who met the blood pressure goals increased from 55% to 66% (P = 0.093). A statistically significant decrease in A1C was found (7.7% vs 7.2%, P = 0.038). The number of patients who met the A1C goal increased from 20% to 41% (P = 0.267) after pharmacist intervention. No medication class was associated with a median proportion of days covered of 80% or greater. However, differences were seen with biguanides (34% vs. 43%, P = 0.004), calcium channel blockers (44% vs. 59%, P < 0.001), and thiazides (28% vs. 39%, P = 0.039) pre- and postintervention. There was no difference in the number of visits to emergency departments or urgent care clinics, or hospitalizations. CONCLUSION: Homeless patients with hypertension and type 2 diabetes who had at least 1 visit with a pharmacist showed some improved health outcomes. Statistically significant benefits were seen in diabetes management, but not for blood pressure control.


Assuntos
Diabetes Mellitus Tipo 2 , Avaliação de Resultados em Cuidados de Saúde , Farmacêuticos , Pressão Sanguínea , Hemoglobinas Glicadas/análise , Humanos , Estudos Retrospectivos
3.
BMJ Open Qual ; 12(3)2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37730270

RESUMO

Delays in treatment of in-hospital cardiac arrests (IHCAs) are associated with worsened survival. We sought to assess the impact of a bundled intervention on IHCA survival in patients on centralised telemetry. A retrospective quality improvement study was performed of a bundled intervention which incorporated (1) a telemetry hotline for telemetry technicians to reach nursing staff; (2) empowerment of telemetry technicians to directly activate the IHCA response team and (3) a standardised escalation system for automated critical alerts within the nursing mobile phone system. In the 4-year study period, there were 75 IHCAs, including 20 preintervention and 55 postintervention. Cox proportional hazard regression predicts postintervention individuals have a 74% reduced the risk of death (HR 0.26, 95% CI 0.08 to 0.84) during a code and a 55% reduced risk of death (HR 0.45, 95% CI 0.23 to 0.89) prior to hospital discharge. Overall code survival improved from 60.0% to 83.6% (p=0.031) with an improvement in ventricular tachycardia/ventricular fibrillation (VT/VF) code survival from 50.0% to 100.0% (p=0.035). There was no difference in non-telemetry code survival preintervention and postintervention (71.4% vs 71.3%, p=0.999). The bundled intervention, including improved communication between telemetry technicians and nurses as well as empowerment of telemetry technicians to directly activate the IHCA response team, may improve IHCA survival, specifically for VT/VF arrests.


Assuntos
Comunicação , Parada Cardíaca , Humanos , Parada Cardíaca/terapia , Hospitais , Estudos Retrospectivos , Telemetria , Taxa de Sobrevida , Medicina de Emergência , Recursos Humanos de Enfermagem Hospitalar
4.
Front Pharmacol ; 13: 1020123, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36249792

RESUMO

Background: An in silico screen was performed to identify FDA approved drugs that inhibit SARS-CoV-2 main protease (Mpro), followed by in vitro viral replication assays, and in vivo pharmacokinetic studies in mice. These studies identified atovaquone as a promising candidate for inhibiting viral replication. Methods: A 2-center, randomized, double-blind, placebo-controlled trial was performed among patients hospitalized with COVID-19 infection. Enrolled patients were randomized 2:1 to atovaquone 1500 mg BID versus matched placebo. Patients received standard of care treatment including remdesivir, dexamethasone, or convalescent plasma as deemed necessary by the treating team. Saliva was collected at baseline and twice per day for up to 10 days for RNA extraction for SARS-CoV-2 viral load measurement by quantitative reverse-transcriptase PCR. The primary outcome was the between group difference in log-transformed viral load (copies/mL) using a generalized linear mixed-effect models of repeated measures from all samples. Results: Of the 61 patients enrolled; 41 received atovaquone and 19 received placebo. Overall, the population was predominately male (63%) and Hispanic (70%), with a mean age of 51 years, enrolled a mean of 5 days from symptom onset. The log10 viral load was 5.25 copies/mL vs. 4.79 copies/mL at baseline in the atovaquone vs. placebo group. Change in viral load did not differ over time between the atovaquone plus standard of care arm versus the placebo plus standard of care arm. Pharmacokinetic (PK) studies of atovaquone plasma concentration demonstrated a wide variation in atovaquone levels, with an inverse correlation between BMI and atovaquone levels, (Rho -0.45, p = 0.02). In post hoc analysis, an inverse correlation was observed between atovaquone levels and viral load (Rho -0.54, p = 0.005). Conclusion: In this prospective, randomized, placebo-controlled trial, atovaquone did not demonstrate evidence of enhanced SARS-CoV-2 viral clearance compared with placebo. However, based on the observed inverse correlation between atovaquone levels and viral load, additional PK-guided studies may be warranted to examine the antiviral effect of atovaquone in COVID-19 patients.

5.
Endocrinology ; 149(4): 1820-8, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18174286

RESUMO

Catch-up growth is defined as a linear growth rate greater than expected for age after a period of growth inhibition. We hypothesized that catch-up growth occurs because growth-inhibiting conditions conserve the limited proliferative capacity of growth plate chondrocytes, thus slowing the normal process of growth plate senescence. When the growth-inhibiting condition resolves, the growth plates are less senescent and therefore grow more rapidly than normal for age. To test this hypothesis, we administered propylthiouracil to newborn rats for 8 wk to induce hypothyroidism and then stopped the propylthiouracil to allow catch-up growth. In untreated controls, the growth plates underwent progressive, senescent changes in multiple functional and structural characteristics. We also identified genes that showed large changes in mRNA expression in growth plate and used these changes as molecular markers of senescence. In treated animals, after stopping propylthiouracil, these functional, structural, and molecular senescent changes were delayed, compared with controls. This delayed senescence included a delayed decline in longitudinal growth rate, resulting in catch-up growth. The findings demonstrate that growth inhibition due to hypothyroidism slows the developmental program of growth plate senescence, including the normal decline in the rate of longitudinal bone growth, thus accounting for catch-up growth.


Assuntos
Lâmina de Crescimento/fisiologia , Crescimento , Hipotireoidismo/fisiopatologia , Envelhecimento/fisiologia , Animais , Feminino , Propiltiouracila/farmacologia , RNA Mensageiro/análise , Ratos , Ratos Sprague-Dawley
6.
Gene ; 427(1-2): 58-64, 2008 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-18852034

RESUMO

TOMM70 is a subunit of the outer mitochondrial membrane translocase that plays a major role as a receptor of hydrophobic preproteins targeted to mitochondria. We have previously reported that two binding sites for transcription factor NRF-2 in the promoter region of the human TOMM70 gene are essential in activating transcription (Blesa et al., Mitochondrion 2004; 3:251-59. Blesa et al., Biochem Cell Biol 2006; 84:813-22). This region contains thirteen CpG methylation sites, three of which occur in the sequence 5'-CCGG-3' that is specifically recognized by HpaII methylase which modifies the internal cytosine residue. Interestingly, each NRF-2 site contains one CCGG sequence, allowing specific methylation of the NRF-2 sites and, therefore, providing an ideal model to study how methylation of these sites affects promoter activity. In this paper we report that site-specific methylation of the NRF-2 binding sites in the TOMM70 promoter down-regulated expression of a luciferase reporter in HeLa S3 cells. Electrophoretic mobility shift assays confirmed abrogation of NRF-2 binding at the methylated sites. These results suggest that methylation of the TOMM70 promoter in mammalian cells may silence TOMM70 expression. However, studies of methylation degree on DNAs from different sources found no methylation in the promoter regions of TOMM70 and other TOMM/TIMM family genes. Thus, although in vitro methylation inactivates the expression of TOMM70, our results suggest that this is not the mechanism modulating its expression in vivo. Since a number of nuclear genes encoding mitochondrial translocases have NRF-2 binding sequences containing CpG methylation sites, a possible role of methylation as a regulatory mechanism of mitochondrial biogenesis can be ruled out.


Assuntos
Metilação de DNA , Fator de Transcrição de Proteínas de Ligação GA/química , Fator de Transcrição de Proteínas de Ligação GA/genética , Proteínas de Membrana Transportadoras/genética , Proteínas Mitocondriais/genética , Regiões Promotoras Genéticas , Sequência de Bases , Sítios de Ligação , Ilhas de CpG , Vetores Genéticos , Células HeLa , Humanos , Proteínas de Transporte da Membrana Mitocondrial , Proteínas do Complexo de Importação de Proteína Precursora Mitocondrial , Modelos Genéticos , Dados de Sequência Molecular , Oligonucleotídeos/química , Sequências Reguladoras de Ácido Nucleico , Homologia de Sequência do Ácido Nucleico
7.
Biochem Cell Biol ; 86(1): 46-56, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18364745

RESUMO

The human TOMM34 gene encodes a cytosolic protein with chaperone-like activity that helps import some preproteins to the mitochondria by keeping them in an unfolded, import-compatible state. TOMM34 was found to be upregulated frequently in colorectal tumors, suggesting that it also has a role in the growth of cancer cells. In this context, TOMM34 is a potential target for novel anticancer drugs, and it might also be used in the diagnosis of colorectal cancer. Nuclear respiratory factors (NRFs) play an important role in governing the nuclear-mitochondrial interactions implicated in mitochondrial biogenesis. Our previous studies revealed that NRFs promote the expression of the major members of the mitochondrial transport machinery, TOMM70 and TOMM20. Here we report the existence of binding sites for NRF-1, Sp1, and NRF-2 in the 5' region of the human TOMM34 gene. We determined the effects of mutations at these sites on promoter activity in HeLa S3 and A204 cells, in conjunction with chromatin immunoprecipitation experiments, electrophoretic mobility shift assays, and in vivo methylation analysis of the promoter region. We conclude that NRF-1 is the main transcription factor regulating the expression of TOMM34. Sp1 interacts with NRF-1 to stimulate the promoter's full activity.


Assuntos
Regulação da Expressão Gênica , Proteínas de Transporte da Membrana Mitocondrial/genética , Fator 1 Nuclear Respiratório/metabolismo , Regiões Promotoras Genéticas , Fatores de Transcrição/metabolismo , Animais , Sequência de Bases , Linhagem Celular , Neoplasias Colorretais/genética , Neoplasias Colorretais/metabolismo , Metilação de DNA , Análise Mutacional de DNA , Genes Reporter , Humanos , Mitocôndrias/metabolismo , Proteínas de Transporte da Membrana Mitocondrial/metabolismo , Proteínas do Complexo de Importação de Proteína Precursora Mitocondrial , Dados de Sequência Molecular , Fator 1 Nuclear Respiratório/genética , Alinhamento de Sequência , Fator de Transcrição Sp1/metabolismo , Fatores de Transcrição/genética
8.
Bone ; 40(3): 577-86, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17169623

RESUMO

Fibroblast growth factor (FGF) signaling is essential for endochondral bone formation. Mutations cause skeletal dysplasias including achondroplasia, the most common human skeletal dysplasia. Most previous work in this area has focused on embryonic chondrogenesis. To explore the role of FGF signaling in the postnatal growth plate, we quantitated expression of FGFs and FGF receptors (FGFRs) and examined both their spatial and temporal regulation. Toward this aim, rat proximal tibial growth plates and surrounding tissues were microdissected, and specific mRNAs were quantitated by real-time RT-PCR. To assess the FGF system without bias, we first screened for expression of all known FGFs and major FGFR isoforms. Perichondrium expressed FGFs 1, 2, 6, 7, 9, and 18 and, at lower levels, FGFs 21 and 22. Growth plate expressed FGFs 2, 7, 18, and 22. Perichondrial expression was generally greater than growth plate expression, supporting the concept that perichondrial FGFs regulate growth plate chondrogenesis. Nevertheless, FGFs synthesized by growth plate chondrocytes may be physiologically important because of their proximity to target receptors. In growth plate, we found expression of FGFRs 1, 2, and 3, primarily, but not exclusively, the c isoforms. FGFRs 1 and 3, thought to negatively regulate chondrogenesis, were expressed at greater levels and at later stages of chondrocyte differentiation, with FGFR1 upregulated in the hypertrophic zone and FGFR3 upregulated in both proliferative and hypertrophic zones. In contrast, FGFRs 2 and 4, putative positive regulators, were expressed at earlier stages of differentiation, with FGFR2 upregulated in the resting zone and FGFR4 in the resting and proliferative zones. FGFRL1, a presumed decoy receptor, was expressed in the resting zone. With increasing age and decreasing growth velocity, FGFR2 and 4 expression was downregulated in proliferative zone. Perichondrial FGF1, FGF7, FGF18, and FGF22 were upregulated. In summary, we have analyzed the expression of all known FGFs and FGFRs in the postnatal growth plate using a method that is quantitative and highly sensitive. This approach identified ligands and receptors not previously known to be expressed in growth plate and revealed a complex pattern of spatial regulation of FGFs and FGFRs in the different zones of the growth plate. We also found temporal changes in FGF and FGFR expression which may contribute to growth plate senescence and thus help determine the size of the adult skeleton.


Assuntos
Fatores de Crescimento de Fibroblastos/biossíntese , Lâmina de Crescimento/metabolismo , Osteogênese , Animais , Condrócitos/metabolismo , Isoformas de Proteínas/metabolismo , RNA Mensageiro/análise , Ratos , Ratos Sprague-Dawley , Receptores de Fatores de Crescimento de Fibroblastos/biossíntese , Reação em Cadeia da Polimerase Via Transcriptase Reversa
9.
J Endocrinol ; 193(1): 75-84, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17400805

RESUMO

In the growth plate, stem-like cells in the resting zone differentiate into rapidly dividing chondrocytes of the proliferative zone and then terminally differentiate into the non-dividing chondrocytes of the hypertrophic zone. To explore the molecular switches responsible for this two-step differentiation program, we developed a microdissection method to isolate RNA from the resting (RZ), proliferative (PZ), and hypertrophic zones (HZ) of 7-day-old male rats. Expression of approximately 29,000 genes was analyzed by microarray and selected genes verified by real-time PCR. The analysis identified genes whose expression changed dramatically during the differentiation program, including multiple genes functionally related to bone morphogenetic proteins (BMPs). BMP-2 and BMP-6 were upregulated in HZ compared with RZ and PZ (30-fold each, P < 0.01 and 0.001 respectively). In contrast, BMP signaling inhibitors were expressed early in the differentiation pathway; BMP-3 and gremlin were differentially expressed in RZ (100- and 80-fold, compared with PZ, P < 0.001 and 0.005 respectively) and growth differentiation factor (GDF)-10 in PZ (160-fold compared with HZ, P < 0.001). Our findings suggest a BMP signaling gradient across the growth plate, which is established by differential expression of multiple BMPs and BMP inhibitors in specific zones. Since BMPs can stimulate both proliferation and hypertrophic differentiation of growth plate chondrocytes, these findings suggest that low levels of BMP signaling in the resting zone may help maintain these cells in a quiescent state. In the lower RZ, greater BMP signaling may help induce differentiation to proliferative chondrocytes. Farther down the growth plate, even greater BMP signaling may help induce hypertrophic differentiation. Thus, BMP signaling gradients may be a key mechanism responsible for spatial regulation of chondrocyte proliferation and differentiation in growth plate cartilage.


Assuntos
Proteínas Morfogenéticas Ósseas/genética , Condrócitos/citologia , Regulação da Expressão Gênica no Desenvolvimento , Lâmina de Crescimento/metabolismo , Animais , Proteína Morfogenética Óssea 2 , Proteína Morfogenética Óssea 3 , Proteína Morfogenética Óssea 6 , Proteína Morfogenética Óssea 7 , Condrócitos/metabolismo , Citocinas , Perfilação da Expressão Gênica , Glicoproteínas/genética , Fator 10 de Diferenciação de Crescimento , Peptídeos e Proteínas de Sinalização Intercelular/genética , Masculino , Análise de Sequência com Séries de Oligonucleotídeos , Proteínas , RNA Mensageiro/análise , Ratos , Ratos Sprague-Dawley , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fator de Crescimento Transformador beta/genética
10.
Biomaterials ; 26(17): 3511-9, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15621241

RESUMO

Finding a conductive substrate that promotes neural interactions is an essential step for advancing neural interfaces. The biocompatibility and conductive properties of polypyrrole (PPy) make it an attractive substrate for neural scaffolds, electrodes, and devices. Stand-alone polymer implants also provide the additional advantages of flexibility and biodegradability. To examine PPy biocompatibility, dissociated primary cerebral cortical cells were cultured on PPy samples that had been doped with polystyrene-sulfonate (PSS) or sodium dodecylbenzenesulfonate (NaDBS). Various conditions were used for electrodeposition to produce different surface properties. Neural networks grew on all of the PPy surfaces. PPy implants, consisting of the same dopants and conditions, were surgically implanted in the cerebral cortex of the rat. The results were compared to stab wounds and Teflon implants of the same size. Quantification of the intensity and extent of gliosis at 3- and 6-week time points demonstrated that all versions of PPy were at least as biocompatible as Teflon and in fact performed better in most cases. In all of the PPy implant cases, neurons and glial cells enveloped the implant. In several cases, neural tissue was present in the lumen of the implants, allowing contact of the brain parenchyma through the implants.


Assuntos
Córtex Cerebral/efeitos dos fármacos , Córtex Cerebral/patologia , Neurônios/efeitos dos fármacos , Neurônios/patologia , Polímeros/efeitos adversos , Polímeros/química , Próteses e Implantes/efeitos adversos , Pirróis/efeitos adversos , Pirróis/química , Animais , Órgãos Bioartificiais , Materiais Biocompatíveis/efeitos adversos , Materiais Biocompatíveis/química , Células Cultivadas , Análise de Falha de Equipamento , Gliose/induzido quimicamente , Gliose/patologia , Implantes Experimentais , Masculino , Teste de Materiais , Ratos , Ratos Sprague-Dawley
11.
J Mol Endocrinol ; 47(1): 99-107, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21642420

RESUMO

In embryonic growth cartilage, Indian hedgehog (Ihh) and parathyroid hormone-related protein (PTHrP) participate in a negative feedback loop that regulates chondrocyte differentiation. Postnatally, this region undergoes major structural and functional changes. To explore the organization of the Ihh­PTHrP system in postnatal growth plate, we microdissected growth plates of 7-day-old rats into their constituent zones and assessed expression of genes participating in the h­PTHrP feedback loop. Ihh, Patched 1, Smoothened, Gli1, Gli2, Gli3, and Pthr1 were expressed in regions analogous to the expression domains in embryonic growth cartilage. However, PTHrP was expressed in resting zone cartilage, a site that differs from the embryonic source, the periarticular cells. We then used mice in which lacZ has replaced coding sequences of Gli1 and thus serves as a marker for active hedgehog signaling. At 1, 4, 8, and 12 weeks of age, lacZ expression was detected in a pattern analogous to that of embryonic cartilage. The findings support the hypothesis that the embryonic Ihh­PTHrP feedback loop is maintained in the postnatal growth plate except that the source of PTHrP has shifted to a more proximal location in the resting zone.


Assuntos
Lâmina de Crescimento/metabolismo , Proteínas Hedgehog/metabolismo , Proteína Relacionada ao Hormônio Paratireóideo/metabolismo , Tíbia/metabolismo , Animais , Animais Recém-Nascidos , Cartilagem/metabolismo , Feminino , Perfilação da Expressão Gênica , Genes Reporter , Lâmina de Crescimento/anatomia & histologia , Lâmina de Crescimento/crescimento & desenvolvimento , Proteínas Hedgehog/genética , Fatores de Transcrição Kruppel-Like/genética , Fatores de Transcrição Kruppel-Like/metabolismo , Masculino , Camundongos , Especificidade de Órgãos , Proteína Relacionada ao Hormônio Paratireóideo/genética , Ratos , Ratos Sprague-Dawley , Transdução de Sinais/genética , Tíbia/anatomia & histologia , Tíbia/crescimento & desenvolvimento , Transcrição Gênica , beta-Galactosidase/biossíntese , beta-Galactosidase/genética
12.
Bone ; 46(5): 1380-90, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20096814

RESUMO

Growth plates are spatially polarized and structured into three histologically and functionally distinct layers-the resting zone (RZ), proliferative zone (PZ), and hypertrophic zone (HZ). With age, growth plates undergo functional and structural senescent changes including declines of growth rate, proliferation rate, growth plate height and cell number. To explore the mechanisms responsible for spatially-associated differentiation and temporally-associated senescence of growth plate in an unbiased manner, we used microdissection to collect individual growth plate zones from proximal tibiae of 1-week rats and the PZ and early hypertrophic zones of growth plates from 3-, 6-, 9-, and 12-week rats and analyzed gene expression using microarray. We then used bioinformatic approaches to identify significant changes in biological functions, molecular pathways, transcription factors and also to identify specific gene products that can be used as molecular markers for individual zones or for temporal development.


Assuntos
Regulação da Expressão Gênica/fisiologia , Lâmina de Crescimento/metabolismo , Animais , Senescência Celular/genética , Senescência Celular/fisiologia , Condrócitos/metabolismo , Biologia Computacional , Proteínas da Matriz Extracelular/genética , Regulação da Expressão Gênica/genética , Glicoproteínas/genética , Fator 10 de Diferenciação de Crescimento/genética , Lâmina de Crescimento/citologia , Hibridização In Situ , Análise em Microsséries , Microdissecção , Reação em Cadeia da Polimerase , Ratos , Ratos Sprague-Dawley , Fatores de Transcrição/genética , Fatores de Transcrição/fisiologia
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