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1.
Heliyon ; 9(3): e14413, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36967955

RESUMO

Background: Motion Sickness increases risk of performance deficits and safety of flight concerns. The etiology of motion sickness is poorly understood. Here, we attempted to quantify the physiological effects of motion sickness on static balance and determine the genetic predictors associated with these effects. Methods: 16 subjects underwent a disorientation stimulus to induce motion sickness. Motion sickness susceptibility was identified using the Motion Sickness Susceptibility Questionnaire. Postural balance outcomes were measured using two tasks, and small ribonucleic acid profiles were assessed with blood draws before motion sickness stimulus. Differences in postural sway before and after the stimulus as well as effect modification of susceptibility were assessed. A random forest followed by regression tree analysis was constructed for each postural sway variable to determine top genetic and covariate predictors. Findings: Significant differences existed in mean postural balance responses between before and after stimulus. Individuals with longer stimulus survival experienced a greater (but insignificant) perception of sway, even if not displaying increased sway for all conditions. Circulation small ribonucleic acids were differentially expressed between individuals with long and short stimulus survival, many of these microRNA have purported targets in genes related to vestibular disorders. Interpretation: We found motion sickness produces transient motor dysfunction in a healthy military population. Small ribonucleic acids were differentially expressed between subjects with long and short stimulus survival times.

2.
Clin Biomech (Bristol, Avon) ; 96: 105671, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35594783

RESUMO

BACKGROUND: Motion sickness and low back disorders are prevalent and debilitating conditions that affect the health, performance, and operational effectiveness of military aircrews. This study explored the effects of a motion sickness stimulus on biomechanical and genetic factors that could potentially be involved in the causal pathways for both disorders. METHODS: Subjects recruited from a military population were exposed to either a mild (n = 12) or aggressive (n = 16) motion sickness stimulus in a Neuro-Otologic Test Center. The independent variable of interest was the motion sickness stimulus exposure (before vs. after), though differences between mild and aggressive stimuli were also assessed. Dependent measures for the study included motion sickness exposure duration, biomechanical variables (postural stability, gait function, low back function, lumbar spine loading), and gene expression. FINDINGS: Seven of twelve subjects experiencing the mild motion sickness stimulus endured the full 30 min in the NOTC, whereas subjects lasted an average of 13.2 (SD 5.0) minutes in the NOTC with the aggressive motion sickness stimulus. Mild motion sickness exposure led to a significant decrease in the postural stability measure of sway area, though the aggressive motion sickness exposure led to a statistically significant increase in sway area. Both stimuli led to decreases in low back function, though the decrease was only statistically significant for the mild protocol. Both stimuli also led to significant changes in gene expression. INTERPRETATION: Motion sickness may alter standing balance, decrease low back function, and lead to changes in the expression of genes with roles in osteogenesis, myogenesis, development of brain lymphatics, inflammation, neuropathic pain, and more. These results may provide preliminary evidence for a link between motion sickness and low back disorders.


Assuntos
Militares , Enjoo devido ao Movimento , Expressão Gênica , Humanos , Enjoo devido ao Movimento/etiologia , Equilíbrio Postural , Posição Ortostática
3.
Am J Forensic Med Pathol ; 42(4): 367-372, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34793410

RESUMO

ABSTRACT: In this report, we describe 13 cases of drug overdose in Michigan in which valeryl fentanyl was found in postmortem blood. Valeryl fentanyl is a schedule I opioid that is rarely found in drug overdoses in the United States. Although little data exist on the mortality and morbidity associated with valeryl fentanyl, its molecular structure indicates that it would be less potent than fentanyl.When analyzing blood samples for valeryl fentanyl, samples from peripheral sites were sometimes negative for quantitative levels; however, samples from central sites in the same decedent were positive. This could indicate unique pharmacokinetics for valeryl fentanyl, which could have implications for other fentanyl analogs. Given the paucity of pharmacodynamic information, the prohibition of its use, the potential to buttress law enforcement efforts in monitoring drug trafficking trends, and to determine the efficacy of current regulations, laboratories should test for valeryl fentanyl. When testing for valeryl fentanyl, and likely other fentanyl analogs, the site of sample collection is important: central sources of blood are preferred to peripheral sources.


Assuntos
Overdose de Drogas , Transtornos Relacionados ao Uso de Opioides , Analgésicos Opioides , Fentanila , Humanos , Michigan , Estados Unidos
4.
J Skin Cancer ; 2021: 3087579, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34697572

RESUMO

The p53 tumor suppressor integrates upstream signals such as DNA damage and active oncogenes to initiate cell cycle arrest or apoptosis. This response is critical to halting inappropriate growth signals. As such, p53 activity is lost in cancer. In melanoma, however, the p53 gene is intact in a reported 94% of human cases. Rather than direct mutation, p53 is held inactive through interaction with inhibitory proteins. Here, we examine the expression of the two primary inhibitors of p53, MDM2 and MDM4, in genomic databases and biopsy specimens. We find that MDM4 is frequently overexpressed. Moreover, changes in splicing of MDM4 occur frequently and early in melanomagenesis. These changes in splicing must be considered in the design of therapeutic inhibitors of the MDM2/4 proteins for melanoma.

5.
J Clin Invest ; 131(19)2021 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-34428179

RESUMO

BACKGROUNDThe loss of insulin-like growth factor 1 (IGF-1) expression in senescent dermal fibroblasts during aging is associated with an increased risk of nonmelanoma skin cancer (NMSC). We tested how IGF-1 signaling can influence photocarcinogenesis during chronic UVB exposure to determine if fractionated laser resurfacing (FLR) of aged skin, which upregulates dermal IGF-1 levels, can prevent the occurrence of actinic keratosis (AK) and NMSC.METHODSA human skin/immunodeficient mouse xenografting model was used to test the effects of a small molecule inhibitor of the IGF-1 receptor on chronic UVB radiation. Subsequently, the durability of FLR treatment was tested on a cohort of human participants aged 65 years and older. Finally, 48 individuals aged 60 years and older with considerable actinic damage were enrolled in a prospective randomized clinical trial in which they underwent a single unilateral FLR treatment of one lower arm. Numbers of AKs/NMSCs were recorded on both extremities for up to 36 months in blinded fashion.RESULTSXenografting studies revealed that chronic UVB treatment with a topical IGF-1R inhibitor resulted in a procarcinogenic response. A single FLR treatment was durable in restoring appropriate UVB response in geriatric skin for at least 2 years. FLR resulted in sustained reduction in numbers of AKs and decreased numbers of NMSCs in the treated arm (2 NMSCs) versus the untreated arm (24 NMSCs).CONCLUSIONThe elimination of senescent fibroblasts via FLR reduced the procarcinogenic UVB response of aged skin. Thus, wounding therapies are a potentially effective prophylaxis for managing high-risk populations.TRIAL REGISTRATIONClinicalTrials.gov (NCT03906253).FUNDINGNational Institutes of Health, Veterans Administration.


Assuntos
Ceratose Actínica/prevenção & controle , Terapia a Laser/métodos , Envelhecimento da Pele/efeitos da radiação , Neoplasias Cutâneas/prevenção & controle , Idoso , Idoso de 80 Anos ou mais , Animais , Feminino , Humanos , Masculino , Camundongos , Pessoa de Meia-Idade , Receptor IGF Tipo 1/antagonistas & inibidores , Receptor IGF Tipo 1/fisiologia , Raios Ultravioleta
6.
J Cell Physiol ; 234(8): 13220-13232, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-30569573

RESUMO

Mitogen-activated protein kinase 6 (MAPK6) represents an atypical MAPK also known as extracellular signal-regulated kinase 3 (ERK3), which has been shown to play roles in cell motility and metastasis. ERK3 promotes migration and invasion of lung cancer cells and head and neck cancer cells by regulating the expression and/or activity of proteins involved in cancer progression. For instance, ERK3 upregulates matrix metallopeptidases and thereby promotes cancer cell invasiveness, and it phosphorylates tyrosyl-DNA phosphodiesterase 2, thereby enhancing chemoresistance in lung cancer. Here we discovered that ERK3 plays a converse role in melanoma. We observed that BRAF, an oncogenic Ser/Thr kinase, upregulates ERK3 expression levels by increasing both ERK3 messenger RNA levels and protein stability. Interestingly, although BRAF's kinase activity was required for upregulating ERK3 gene transcription, BRAF stabilized ERK3 protein in a kinase-independent fashion. We further demonstrate that ERK3 inhibits the migration, proliferation and colony formation of melanoma cells. In line with this, high level of ERK3 predicted increased survival among patients with melanomas. Taken together, these results indicate that ERK3 acts as a potent suppressor of melanoma cell growth and invasiveness.


Assuntos
Melanoma/enzimologia , Melanoma/patologia , Proteína Quinase 6 Ativada por Mitógeno/metabolismo , Invasividade Neoplásica/patologia , Animais , Linhagem Celular Tumoral , Proliferação de Células/fisiologia , Regulação Neoplásica da Expressão Gênica/fisiologia , Xenoenxertos , Humanos , Camundongos , Neoplasias Cutâneas/enzimologia , Neoplasias Cutâneas/patologia
7.
Dev Biol ; 433(2): 433-447, 2018 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-28774726

RESUMO

Planarian flatworms are popular models for the study of regeneration and stem cell biology in vivo. Technical advances and increased availability of genetic information have fueled the discovery of molecules responsible for stem cell pluripotency and regeneration in flatworms. Unfortunately, most of the planarian research performed worldwide utilizes species that are not natural habitants of North America, which limits their availability to newcomer laboratories and impedes their distribution for educational activities. In order to circumvent these limitations and increase the genetic information available for comparative studies, we sequenced the transcriptome of Girardia dorotocephala, a planarian species pandemic and commercially available in North America. A total of 254,802,670 paired sequence reads were obtained from RNA extracted from intact individuals, regenerating fragments, as well as freshly excised auricles of a clonal line of G. dorotocephala (MA-C2), and used for de novo assembly of its transcriptome. The resulting transcriptome draft was validated through functional analysis of genetic markers of stem cells and their progeny in G. dorotocephala. Akin to orthologs in other planarian species, G. dorotocephala Piwi1 (GdPiwi1) was found to be a robust marker of the planarian stem cell population and GdPiwi2 an essential component for stem cell-driven regeneration. Identification of G. dorotocephala homologs of the early stem cell descendent marker PROG-1 revealed a family of lysine-rich proteins expressed during epithelial cell differentiation. Sequences from the MA-C2 transcriptome were found to be 98-99% identical to nucleotide sequences from G. dorotocephala populations with different chromosomal number, demonstrating strong conservation regardless of karyotype evolution. Altogether, this work establishes G. dorotocephala as a viable and accessible option for analysis of gene function in North America.


Assuntos
Proteínas Argonautas/genética , Genes de Helmintos , Proteínas de Helminto/genética , Planárias/genética , Células-Tronco/citologia , Transcriptoma , Animais , Proteínas Argonautas/fisiologia , Biomarcadores , Clonagem de Organismos , Proteínas de Helminto/biossíntese , Homeostase/genética , Família Multigênica , Interferência de RNA , RNA de Cadeia Dupla/administração & dosagem , RNA de Cadeia Dupla/genética , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Regeneração/genética , Reprodução Assexuada , Análise de Sequência de RNA
8.
Int J Mol Sci ; 18(9)2017 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-28895891

RESUMO

Serine-arginine-rich (SR) or SR-like splicing factors interact with exon junction complex proteins during pre-mRNA processing to promote mRNA packaging into mature messenger ribonucleoproteins (mRNPs) and to dictate mRNA stability, nuclear export, and translation. The SR protein family is complex, and while many classical SR proteins have well-defined mRNA processing functions, those of other SR-like proteins is unclear. Here, we show that depletion of the homologous non-classical serine-arginine-rich (SR) splicing factors Bcl2-associated transcription factor (Btf or BCLAF) and thyroid hormone receptor-associated protein of 150 kDa (TRAP150) causes mitotic defects. We hypothesized that the depletion of these SR-like factors affects mitosis indirectly through an altered expression of mitotic checkpoint regulator transcripts. We observed an altered abundance of transcripts that encode mitotic regulators and mitotic chromosome misalignment defects following Btf and/or TRAP150 depletion. We propose that, in addition to their previously reported roles in maintaining mRNA distribution, Btf and TRAP150 control the abundance of transcripts encoding mitotic regulators, thereby affecting mitotic progression in human cells.


Assuntos
Cromossomos/metabolismo , Proteínas de Ligação a DNA/metabolismo , Proteínas Repressoras/metabolismo , Fatores de Processamento de Serina-Arginina/metabolismo , Fatores de Transcrição/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Transporte Ativo do Núcleo Celular , Ciclo Celular , Núcleo Celular , Proteínas de Ligação a DNA/genética , Regulação da Expressão Gênica , Células HeLa , Humanos , Proteínas Nucleares/metabolismo , Precursores de RNA , Estabilidade de RNA , RNA Mensageiro/metabolismo , RNA Interferente Pequeno/metabolismo , Proteínas de Ligação a RNA/metabolismo , Ribonucleoproteínas , Fatores de Processamento de Serina-Arginina/genética , Fatores de Transcrição/genética
9.
J Forensic Sci ; 62(5): 1304-1307, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28168714

RESUMO

This manuscript describes the use of comparative radiography of the chest to facilitate positive identification of human remains in advanced stages of decomposition. The method reported by Stephan et al. for positive identification of dry, disarticulated skeletal elements was used on semifleshed, decomposing remains. Positive identification was established through multiple points of concordance observed in radiographs of the left and right clavicles and the C5-T1 vertebrae. This case study demonstrates the applicability of the Stephan et al.'s method in cases involving decomposing remains.


Assuntos
Vértebras Cervicais/diagnóstico por imagem , Clavícula/diagnóstico por imagem , Antropologia Forense/métodos , Vértebras Torácicas/diagnóstico por imagem , Restos Mortais , Humanos
10.
J Low Genit Tract Dis ; 21(2): 150-156, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27984345

RESUMO

OBJECTIVE: The aim of the study was to review the current nomenclature and literature examining microbiome cytokine, genomic, proteomic, and glycomic molecular biomarkers in identifying markers related to the understanding of the pathophysiology and diagnosis of vulvodynia (VVD). MATERIALS AND METHODS: Computerized searches of MEDLINE and PubMed were conducted focused on terminology, classification, and "omics" variations of VVD. Specific MESH terms used were VVD, vestibulodynia, metagenomics, vaginal fungi, cytokines, gene, protein, inflammation, glycomic, proteomic, secretomic, and genomic from 2001 to 2016. Using combined VVD and vestibulodynia MESH terms, 7 references were identified related to vaginal fungi, 15 to cytokines, 18 to gene, 43 to protein, 38 to inflammation, and 2 to genomic. References from identified publications were manually searched and cross-referenced to identify additional relevant articles. A narrative synthesis of the articles was conducted; however, meta-analysis was not conducted because of substantial heterogeneity in the studies and limited numbers of control-matched studies. RESULTS: Varying definitions of VVD complicate a meta-analysis, and standard definitions will better allow for comparisons of studies and enhance the applicability of evidence to patient populations. Although data are still limited, genomic and molecular diagnostic testings continue to be investigated as potential tools for the diagnosis of VVD. CONCLUSIONS: Standardized nomenclature will allow for comparability of studies and progress in research related to the pathophysiology of VVD and to facilitate clinical decision making and treatment choices. Although the current understanding of the pathogenesis of VVD is limited, there are new opportunities to explore potential diagnostic markers differences in women with VVD, which may lead to targeted therapy.


Assuntos
Vulvodinia/diagnóstico , Vulvodinia/fisiopatologia , Feminino , Humanos , Terminologia como Assunto , Vulvodinia/etiologia
11.
Cancer Biomark ; 16(4): 575-97, 2016 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-27002761

RESUMO

BACKGROUND: Skin melanocytes can give rise to benign and malignant neoplasms. Discrimination of an early melanoma from an unusual/atypical benign nevus can represent a significant challenge. However, previous studies have shown that in contrast to benign nevi, melanoma demonstrates pervasive chromosomal aberrations. OBJECTIVE: This substantial difference between melanoma and benign nevi can be exploited to discriminate between melanoma and benign nevi. METHODS: Array-comparative genomic hybridization (aCGH) is an approach that can be used on DNA extracted from formalin-fixed paraffin-embedded (FFPE) tissues to assess the entire genome for the presence of changes in DNA copy number. In this study, high resolution, genome-wide single-nucleotide polymorphism (SNP) arrays were utilized to perform comprehensive and detailed analyses of recurrent copy number aberrations in 41 melanoma samples in comparison with 21 benign nevi. RESULTS: We found statistically significant copy number gains and losses within melanoma samples. Some of the identified aberrations are previously implicated in melanoma. Moreover, novel regions of copy number alterations were identified, revealing new candidate genes potentially involved in melanoma pathogenesis. CONCLUSIONS: Taken together, these findings can help improve melanoma diagnosis and introduce novel melanoma therapeutic targets.


Assuntos
Variações do Número de Cópias de DNA , Melanócitos/metabolismo , Melanoma/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Biópsia , Aberrações Cromossômicas , Hibridização Genômica Comparativa , Feminino , Amplificação de Genes , Humanos , Masculino , Melanócitos/patologia , Melanoma/patologia , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Nevo/genética , Nevo/patologia , Polimorfismo de Nucleotídeo Único , Deleção de Sequência , Adulto Jovem
12.
Anal Biochem ; 486: 17-23, 2015 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-26126956

RESUMO

As new technologies come within reach for the average cytogenetic laboratory, the study of chromosome structure has become increasingly more sophisticated. Resolution has improved from karyotyping (in which whole chromosomes are discernible) to fluorescence in situ hybridization and comparative genomic hybridization (CGH, with which specific megabase regions are visualized), array-based CGH (aCGH, examining hundreds of base pairs), and next-generation sequencing (providing single base pair resolution). Whole genome next-generation sequencing remains a cost-prohibitive method for many investigators. Meanwhile, the cost of aCGH has been reduced during recent years, even as resolution has increased and protocols have simplified. However, aCGH presents its own set of unique challenges. DNA of sufficient quantity and quality to hybridize to arrays and provide meaningful results is required. This is especially difficult for DNA from formalin-fixed paraffin-embedded (FFPE) tissues. Here, we compare three different methods for acquiring DNA of sufficient length, purity, and "amplifiability" for aCGH and other downstream applications. Phenol-chloroform extraction and column-based commercial kits were compared with adaptive focused acoustics (AFA). Of the three extraction methods, AFA samples showed increased amplicon length and decreased polymerase chain reaction (PCR) failure rate. These findings support AFA as an improvement over previous DNA extraction methods for FFPE tissues.


Assuntos
Fracionamento Químico/métodos , DNA/isolamento & purificação , Formaldeído/farmacologia , Genoma Humano/genética , Inclusão em Parafina , Fixação de Tecidos , Adolescente , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Controle de Qualidade , Adulto Jovem
13.
PLoS One ; 8(8): e71143, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23940705

RESUMO

The ectoparasitic mite, Sarcoptes scabiei that burrows in the epidermis of mammalian skin has a long co-evolution with its hosts. Phenotypic studies show that the mites have the ability to modulate cytokine secretion and expression of cell adhesion molecules in cells of the skin and other cells of the innate and adaptive immune systems that may assist the mites to survive in the skin. The purpose of this study was to identify genes in keratinocytes and fibroblasts in human skin equivalents (HSEs) that changed expression in response to the burrowing of live scabies mites. Overall, of the more than 25,800 genes measured, 189 genes were up-regulated >2-fold in response to scabies mite burrowing while 152 genes were down-regulated to the same degree. HSEs differentially expressed large numbers of genes that were related to host protective responses including those involved in immune response, defense response, cytokine activity, taxis, response to other organisms, and cell adhesion. Genes for the expression of interleukin-1α (IL-1α) precursor, IL-1ß, granulocyte/macrophage-colony stimulating factor (GM-CSF) precursor, and G-CSF precursor were up-regulated 2.8- to 7.4-fold, paralleling cytokine secretion profiles. A large number of genes involved in epithelium development and keratinization were also differentially expressed in response to live scabies mites. Thus, these skin cells are directly responding as expected in an inflammatory response to products of the mites and the disruption of the skin's protective barrier caused by burrowing. This suggests that in vivo the interplay among these skin cells and other cell types, including Langerhans cells, dendritic cells, lymphocytes and endothelial cells, is responsible for depressing the host's protective response allowing these mites to survive in the skin.


Assuntos
Regulação da Expressão Gênica , Sarcoptes scabiei/fisiologia , Escabiose/genética , Escabiose/parasitologia , Pele/metabolismo , Pele/parasitologia , Animais , Extratos Celulares/farmacologia , Humanos , Análise em Microsséries , Pele/efeitos dos fármacos , Pele Artificial/parasitologia , Transcriptoma
14.
PLoS One ; 7(8): e42034, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22870278

RESUMO

BACKGROUND: MDM4, also called MDMX or HDMX in humans, is an important negative regulator of the p53 tumor suppressor. MDM4 is overexpressed in about 17% of all cancers and more frequently in some types, such as colon cancer or retinoblastoma. MDM4 is known to be post-translationally regulated by MDM2-mediated ubiquitination to decrease its protein levels in response to genotoxic stress, resulting in accumulation and activation of p53. At the transcriptional level, MDM4 gene regulation has been less clearly understood. We have reported that DNA damage triggers loss of MDM4 mRNA and a concurrent increase in p53 activity. These experiments attempt to determine a mechanism for down-regulation of MDM4 mRNA. METHODOLOGY/PRINCIPAL FINDINGS: Here we report that MDM4 mRNA is a target of hsa-mir-34a (miR-34a). MDM4 mRNA contains a lengthy 3' untranslated region; however, we find that it is a miR-34a site within the open reading frame (ORF) of exon 11 that is responsible for the repression. Overexpression of miR-34a, but not a mutant miR-34a, is sufficient to decrease MDM4 mRNA levels to an extent identical to those of known miR-34a target genes. Likewise, MDM4 protein levels are decreased by miR-34a overexpression. Inhibition of endogenous miR-34a increased expression of miR-34a target genes and MDM4. A portion of MDM4 exon 11 containing this 8mer-A1 miR-34a site fused to a luciferase reporter gene is sufficient to confer responsiveness, being inhibited by additional expression of exogenous mir-34a and activated by inhibition of miR-34a. CONCLUSIONS/SIGNIFICANCE: These data establish a mechanism for the observed DNA damage-induced negative regulation of MDM4 and potentially provide a novel means to manipulate MDM4 expression without introducing DNA damage.


Assuntos
Regulação da Expressão Gênica/fisiologia , MicroRNAs/metabolismo , Proteínas Nucleares/biossíntese , Fases de Leitura Aberta , Proteínas Proto-Oncogênicas/biossíntese , RNA Mensageiro/metabolismo , Ubiquitinação/fisiologia , Proteínas de Ciclo Celular , Linhagem Celular Tumoral , Dano ao DNA/fisiologia , Humanos , MicroRNAs/genética , Proteínas Nucleares/genética , Proteínas Proto-Oncogênicas/genética , RNA Mensageiro/genética , Proteína Supressora de Tumor p53/biossíntese , Proteína Supressora de Tumor p53/genética
15.
J Cell Sci ; 124(Pt 24): 4286-98, 2011 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-22193954

RESUMO

Serine-arginine-rich (SR) proteins play a key role in alternative pre-mRNA splicing in eukaryotes. We recently showed that a large SR protein called Son has unique repeat motifs that are essential for maintaining the subnuclear organization of pre-mRNA processing factors in nuclear speckles. Motif analysis of Son highlights putative RNA interaction domains that suggest a direct role for Son in pre-mRNA splicing. Here, we used in situ approaches to show that Son localizes to a reporter minigene transcription site, and that RNAi-mediated Son depletion causes exon skipping on reporter transcripts at this transcription site. A genome-wide exon microarray analysis was performed to identify human transcription and splicing targets of Son. Our data show that Son-regulated splicing encompasses all known types of alternative splicing, the most common being alternative splicing of cassette exons. We confirmed that knockdown of Son leads to exon skipping in pre-mRNAs for chromatin-modifying enzymes, including ADA, HDAC6 and SetD8. This study reports a comprehensive view of human transcription and splicing targets for Son in fundamental cellular pathways such as integrin-mediated cell adhesion, cell cycle regulation, cholesterol biosynthesis, apoptosis and epigenetic regulation of gene expression.


Assuntos
Processamento Alternativo , Proteínas de Ligação a DNA/fisiologia , Proteínas Nucleares/fisiologia , Precursores de RNA/metabolismo , RNA Mensageiro/metabolismo , Proteínas de Ligação a RNA/fisiologia , Proteínas de Ligação a DNA/antagonistas & inibidores , Proteínas de Ligação a DNA/química , Células HeLa , Humanos , Metáfase , Antígenos de Histocompatibilidade Menor , Proteínas Nucleares/antagonistas & inibidores , Proteínas Nucleares/química , Interferência de RNA , Proteínas de Ligação a RNA/antagonistas & inibidores , Proteínas de Ligação a RNA/química , Fatores de Processamento de Serina-Arginina , Fuso Acromático/ultraestrutura , Transcrição Gênica , Tropomiosina/genética
16.
Front Biosci (Landmark Ed) ; 16(3): 1144-56, 2011 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-21196223

RESUMO

Mouse double minute 4 (MDM4), also known as MDMX or HDMX (human MDMX), is a critical negative regulator of the tumor suppressor p53. Under normal growth conditions, MDM4 contributes to the repression of p53 activity. Upon DNA damage, it becomes important to down-regulate MDM4 to allow a full p53 response. Here, the mechanisms by which MDM4 activity is controlled are reviewed and discussed, starting with alterations in copy number, then control of transcription, mRNA stability, translation, and finally post-translational interactions, modifications, localization, and targeting by recently developed drugs.


Assuntos
Proteínas Proto-Oncogênicas c-mdm2/genética , Processamento Alternativo , Animais , Dano ao DNA , Regulação da Expressão Gênica , Humanos , Camundongos , MicroRNAs/genética , Neoplasias/genética , Processamento de Proteína Pós-Traducional , Proteínas Proto-Oncogênicas c-mdm2/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-mdm2/fisiologia , RNA Mensageiro/metabolismo , Proteína Supressora de Tumor p53/antagonistas & inibidores , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/fisiologia
17.
J Forensic Sci ; 55(5): 1389-92, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20456585

RESUMO

Intracerebral hemorrhage (ICH) is a well-recognized complication of recreational cocaine use. The precise mechanism of the cocaine-induced hemorrhagic event is unclear, although multiple factors have been implicated. We report a case of a 62-year-old woman who suffered left parieto-occipital ICH with herniation and death, following a cocaine binge. Microscopic examination also revealed extensive cerebral amyloid angiopathy (CAA) in the vicinity of the hemorrhage. We additionally studied brain tissue in eight subjects between ages of 60 and 80 who were positive for cocaine metabolites at autopsy; of these, none had vascular amyloid-ß deposits by immunohistochemistry. Whereas we found no evidence that chronic cocaine use is a risk factor for CAA, given the age-associated nature of CAA and the aging population using cocaine, CAA-induced hemorrhage in the setting of cocaine use may be more common than recognized. This is the first reported case of CAA-associated ICH precipitated by cocaine.


Assuntos
Angiopatia Amiloide Cerebral/patologia , Hemorragia Cerebral/induzido quimicamente , Cocaína/efeitos adversos , Inibidores da Captação de Dopamina/efeitos adversos , Hemorragia Cerebral/patologia , Feminino , Patologia Legal , Humanos , Pessoa de Meia-Idade
18.
Aging (Albany NY) ; 1(1): 89-108, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19946469

RESUMO

While half of all human tumors possess p53 mutations, inactivation of wild-type p53 can also occur through a variety of mechanisms that do not involve p53 gene mutation or deletion. Our laboratory has been interested in tumor cells possessing wild-type p53 protein and elevated levels of HdmX and/or Hdm2, two critical negative regulators of p53 function. In this study we utilized RNAi to knockdown HdmX or Hdm2 in MCF7 human breast cancer cells, which harbor wild-type p53 and elevated levels of HdmX and Hdm2 then examined gene expression changes and effects on cell growth.Cell cycle and growth assays confirmed that the loss of either HdmX or Hdm2 led to a significant growth inhibition and G1cell cycle arrest. Although the removal of overexpressed HdmX/2 appears limited to an anti-proliferative effect in MCF7cells, the loss of HdmX and/or Hdm2 enhanced cytotoxicity in these same cells exposed to DNA damage. Through the use of Affymetrix GeneChips and subsequent RT-qPCR validations, we uncovered a subset of anti-proliferative p53 target genes activated upon HdmX/2 knockdown. Interestingly, a second set of genes, normally transactivated by E2F1 as cells transverse the G1-S phase boundary, were found repressed in a p21-dependent manner following HdmX/2 knockdown.Taken together, these results provide novel insights into the reactivation of p53 in cells overexpressing HdmX and Hdm2.


Assuntos
Dano ao DNA/genética , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica/fisiologia , Proteínas Nucleares/genética , Proteínas Proto-Oncogênicas c-mdm2/genética , Proteínas Proto-Oncogênicas/genética , Interferência de RNA , Proteína Supressora de Tumor p53/genética , Actinas/genética , Neoplasias da Mama/metabolismo , Proteínas de Ciclo Celular , Linhagem Celular Tumoral , Proliferação de Células , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/genética , Cisplatino/farmacologia , Ciclina A2/genética , Inibidor de Quinase Dependente de Ciclina p21/genética , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Dano ao DNA/efeitos dos fármacos , Regulação para Baixo/genética , Doxorrubicina/farmacologia , Fator de Transcrição E2F1/genética , Feminino , Fase G1/genética , Expressão Gênica/genética , Humanos , Proteínas Imediatamente Precoces/genética , Análise de Sequência com Séries de Oligonucleotídeos , Proteínas Proto-Oncogênicas c-bcl-2/genética , RNA Interferente Pequeno/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transfecção , Proteína Supressora de Tumor p53/metabolismo , Proteínas Supressoras de Tumor/genética , Regulação para Cima/genética
19.
J Org Chem ; 73(19): 7441-3, 2008 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-18759482

RESUMO

The synthesis of cribrostatin 6 (1) is described. A regioselective bromination, a biaryl coupling, and an intramolecular cyclization are the key steps in the synthesis.


Assuntos
Isoquinolinas/síntese química , Anti-Infecciosos/síntese química , Antineoplásicos/síntese química , Produtos Biológicos/síntese química , Ciclização , Halogenação
20.
Org Lett ; 9(17): 3255-7, 2007 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-17658834

RESUMO

The first total synthesis of santiagonamine (1) is achieved in 12 steps from isovanillin. A palladium-catalyzed Ullmann cross-coupling reaction and a photocyclization are the key steps in the synthesis.


Assuntos
Alcaloides/síntese química , Cumarínicos/síntese química , Isoquinolinas/síntese química , Benzaldeídos/química , Berberis/química , Plantas Medicinais/química , Cicatrização
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