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1.
Int J Mol Sci ; 21(19)2020 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-33003377

RESUMO

The world is currently experiencing the worst health pandemic since the Spanish flu in 1918-the COVID-19 pandemic-caused by the coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This pandemic is the world's third wake-up call this century. In 2003 and 2012, the world experienced two major coronavirus outbreaks, SARS-CoV-1 and Middle East Respiratory syndrome coronavirus (MERS-CoV), causing major respiratory tract infections. At present, there is neither a vaccine nor a cure for COVID-19. The severe COVID-19 symptoms of hyperinflammation, catastrophic damage to the vascular endothelium, thrombotic complications, septic shock, brain damage, acute disseminated encephalomyelitis (ADEM), and acute neurological and psychiatric complications are unprecedented. Many COVID-19 deaths result from the aftermath of hyperinflammatory complications, also referred to as the "cytokine storm syndrome", endotheliitus and blood clotting, all with the potential to cause multiorgan dysfunction. The sphingolipid rheostat plays integral roles in viral replication, activation/modulation of the immune response, and importantly in maintaining vasculature integrity, with sphingosine 1 phosphate (S1P) and its cognate receptors (SIPRs: G-protein-coupled receptors) being key factors in vascular protection against endotheliitus. Hence, modulation of sphingosine kinase (SphK), S1P, and the S1P receptor pathway may provide significant beneficial effects towards counteracting the life-threatening, acute, and chronic complications associated with SARS-CoV-2 infection. This review provides a comprehensive overview of SARS-CoV-2 infection and disease, prospective vaccines, and current treatments. We then discuss the evidence supporting the targeting of SphK/S1P and S1P receptors in the repertoire of COVID-19 therapies to control viral replication and alleviate the known and emerging acute and chronic symptoms of COVID-19. Three clinical trials using FDA-approved sphingolipid-based drugs being repurposed and evaluated to help in alleviating COVID-19 symptoms are discussed.


Assuntos
Betacoronavirus/efeitos dos fármacos , Infecções por Coronavirus/tratamento farmacológico , Lisofosfolipídeos/metabolismo , Fosfotransferases (Aceptor do Grupo Álcool)/antagonistas & inibidores , Pneumonia Viral/tratamento farmacológico , Esfingolipídeos/farmacologia , Receptores de Esfingosina-1-Fosfato/antagonistas & inibidores , Esfingosina/análogos & derivados , Replicação Viral/efeitos dos fármacos , Betacoronavirus/isolamento & purificação , COVID-19 , Humanos , Pandemias , SARS-CoV-2 , Esfingosina/metabolismo
2.
Mol Cancer ; 17(1): 37, 2018 02 19.
Artigo em Inglês | MEDLINE | ID: mdl-29455665

RESUMO

Regulation of the PI-3 kinase (PI3K)/Akt signalling pathway is essential for maintaining the integrity of fundamental cellular processes, cell growth, survival, death and metabolism, and dysregulation of this pathway is implicated in the development and progression of cancers. Receptor tyrosine kinases (RTKs) are major upstream regulators of PI3K/Akt signalling. The phosphatase and tensin homologue (PTEN), a well characterised tumour suppressor, is a prime antagonist of PI3K and therefore a negative regulator of this pathway. Loss or inactivation of PTEN, which occurs in many tumour types, leads to overactivation of RTK/PI3K/Akt signalling driving tumourigenesis. Cellular PTEN levels are tightly regulated by a number of transcriptional, post-transcriptional and post-translational regulatory mechanisms. Of particular interest, transcription of the PTEN pseudogene, PTENP1, produces sense and antisense transcripts that exhibit post-transcriptional and transcriptional modulation of PTEN expression respectively. These additional levels of regulatory complexity governing PTEN expression add to the overall intricacies of the regulation of RTK/PI-3 K/Akt signalling. This review will discuss the regulation of oncogenic PI3K signalling by PTEN (the regulator) with a focus on the modulatory effects of the sense and antisense transcripts of PTENP1 on PTEN expression, and will further explore the potential for new therapeutic opportunities in cancer treatment.


Assuntos
Neoplasias/metabolismo , PTEN Fosfo-Hidrolase/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Animais , Antineoplásicos/uso terapêutico , Humanos , MicroRNAs/genética , Neoplasias/tratamento farmacológico , PTEN Fosfo-Hidrolase/genética , Proteínas Tirosina Quinases/genética , Proteínas Tirosina Quinases/metabolismo , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética
3.
J Gene Med ; 20(5): e3017, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29578255

RESUMO

BACKGROUND: Gene therapy is one treatment that may ultimately cure type 1 diabetes. We have previously shown that the introduction of furin-cleavable human insulin (INS-FUR) to the livers in several animal models of diabetes resulted in the reversal of diabetes and partial pancreatic transdifferentiation of liver cells. The present study investigated whether streptozotocin-diabetes could be reversed in FRG mice in which chimeric mouse-human livers can readily be established and, in addition, whether pancreatic transdifferentiation occurred in the engrafted human hepatocytes. METHODS: Engraftment of human hepatocytes was confirmed by measuring human albumin levels. Following delivery of the empty vector or the INS-FUR vector to diabetic FRG mice, mice were monitored for weight and blood glucose levels. Intraperitoneal glucose tolerance tests (IPGTTs) were performed. Expression levels of pancreatic hormones and transcription factors were determined by a reverse transcriptase-polymerase chain reaction (RT-PCR) and immunohistochemistry. RESULTS: Diabetes was reversed for a period of 60 days (experimental endpoint) after transduction with INS-FUR. IPGTTs of the insulin-transduced animals were not significantly different from nondiabetic animals. Immunofluorescence microscopy revealed the expression of human albumin and insulin in transduced liver samples. Quantitative RT-PCR showed expression of human and mouse endocrine hormones and ß-cell transcription factors, indicating partial pancreatic transdifferentiation of mouse and human hepatocytes. Nonfasting human C-peptide levels were significantly higher than mouse levels, suggesting that transdifferentiated human hepatocytes made a significant contribution to the reversal of diabetes. CONCLUSIONS: These data show that human hepatocytes can be induced to undergo partial pancreatic transdifferentiation in vivo, indicating that the technology holds promise for the treatment of type 1 diabetes.


Assuntos
Transdiferenciação Celular/genética , Diabetes Mellitus Experimental/terapia , Diabetes Mellitus Tipo 1/terapia , Hepatócitos/metabolismo , Células Secretoras de Insulina/metabolismo , Insulina/metabolismo , Fígado/metabolismo , Animais , Transplante de Células/métodos , Células Cultivadas , Diabetes Mellitus Experimental/genética , Diabetes Mellitus Tipo 1/genética , Modelos Animais de Doenças , Hepatócitos/citologia , Humanos , Insulina/genética , Células Secretoras de Insulina/citologia , Lentivirus/genética , Fígado/citologia , Camundongos , Transplante Heterólogo
4.
Int J Mol Sci ; 18(9)2017 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-28869494

RESUMO

Sphingosine kinase (SphK) is a lipid enzyme that maintains cellular lipid homeostasis. Two SphK isozymes, SphK1 and SphK2, are expressed from different chromosomes and several variant isoforms are expressed from each of the isozymes, allowing for the multi-faceted biological diversity of SphK activity. Historically, SphK1 is mainly associated with oncogenicity, however in reality, both SphK1 and SphK2 isozymes possess oncogenic properties and are recognized therapeutic targets. The absence of mutations of SphK in various cancer types has led to the theory that cancer cells develop a dependency on SphK signaling (hyper-SphK signaling) or "non-oncogenic addiction". Here we discuss additional theories of SphK cellular mislocation and aberrant "dicing and splicing" as contributors to cancer cell biology and as key determinants of the success or failure of SphK/S1P (sphingosine 1 phosphate) based therapeutics.


Assuntos
Regulação Neoplásica da Expressão Gênica , Família Multigênica , Neoplasias/etiologia , Neoplasias/metabolismo , Fosfotransferases (Aceptor do Grupo Álcool)/genética , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , Splicing de RNA , Animais , Modelos Animais de Doenças , Evolução Molecular , Humanos , Isoenzimas , Lisofosfolipídeos/metabolismo , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Transporte Proteico , Receptores de Lisoesfingolipídeo/metabolismo , Transdução de Sinais , Esfingosina/análogos & derivados , Esfingosina/metabolismo
5.
Int J Mol Sci ; 17(4): 534, 2016 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-27070593

RESUMO

Due to the limitations of current treatment regimes, gene therapy is a promising strategy being explored to correct blood glucose concentrations in diabetic patients. In the current study, we used a retroviral vector to deliver either the human insulin gene alone, the rat NeuroD1 gene alone, or the human insulin gene and rat NeuroD1 genes together, to the rat liver cell line, H4IIE, to determine if storage of insulin and pancreatic transdifferentiation occurred. Stable clones were selected and expanded into cell lines: H4IIEins (insulin gene alone), H4IIE/ND (NeuroD1 gene alone), and H4IIEins/ND (insulin and NeuroD1 genes). The H4IIEins cells did not store insulin; however, H4IIE/ND and H4IIEins/ND cells stored 65.5 ± 5.6 and 1475.4 ± 171.8 pmol/insulin/5 × 106 cells, respectively. Additionally, several ß cell transcription factors and pancreatic hormones were expressed in both H4IIE/ND and H4IIEins/ND cells. Electron microscopy revealed insulin storage vesicles in the H4IIE/ND and H4IIEins/ND cell lines. Regulated secretion of insulin to glucose (0-20 mmol/L) was seen in the H4IIEins/ND cell line. The H4IIEins/ND cells were transplanted into diabetic immunoincompetent mice, resulting in normalization of blood glucose. This data shows that the expression of NeuroD1 and insulin in liver cells may be a useful strategy for inducing islet neogenesis and reversing diabetes.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Engenharia Celular/métodos , Transdiferenciação Celular , Glucose/metabolismo , Insulina/genética , Insulina/metabolismo , Fígado/citologia , Animais , Linhagem Celular , Diabetes Mellitus/genética , Diabetes Mellitus/terapia , Técnicas de Transferência de Genes , Terapia Genética , Humanos , Fígado/metabolismo , Masculino , Camundongos SCID , Ratos
6.
Nutr Rev ; 82(2): 193-209, 2024 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-37290429

RESUMO

CONTEXT: There is substantial evidence that reduced short-chain fatty acids (SCFAs) in the gut are associated with obesity and type 2 diabetes, although findings from clinical interventions that can increase SCFAs are inconsistent. OBJECTIVE: This systematic review and meta-analysis aimed to assess the effect of SCFA interventions on fasting glucose, fasting insulin, and homeostatic model assessment of insulin resistance (HOMA-IR). DATA SOURCES: Relevant articles published up to July 28, 2022, were extracted from PubMed and Embase using the MeSH (Medical Subject Headings) terms of the defined keywords [(short-chain fatty acids) AND (obesity OR diabetes OR insulin sensitivity)] and their synonyms. Data analyses were performed independently by two researchers who used the Cochrane meta-analysis checklist and the PRISMA guidelines. DATA EXTRACTION: Clinical studies and trials that measured SCFAs and reported glucose homeostasis parameters were included in the analysis. Standardized mean differences (SMDs) with 95%CIs were calculated using a random-effects model in the data extraction tool Review Manager version 5.4 (RevMan 5.4). The risk-of-bias assessment was performed following the Cochrane checklist for randomized and crossover studies. DATA ANALYSIS: In total, 6040 nonduplicate studies were identified, 23 of which met the defined criteria, reported fasting insulin, fasting glucose, or HOMA-IR values, and reported change in SCFA concentrations post intervention. Meta-analyses of these studies indicated that fasting insulin concentrations were significantly reduced (overall effect: SMD = -0.15; 95%CI = -0.29 to -0.01, P = 0.04) in treatment groups, relative to placebo groups, at the end of the intervention. Studies with a confirmed increase in SCFAs at the end of intervention also had a significant effect on lowering fasting insulin (P = 0.008). Elevated levels of SCFAs, compared with baseline levels, were associated with beneficial effects on HOMA-IR (P < 0.00001). There was no significant change in fasting glucose concentrations. CONCLUSION: Increased postintervention levels of SCFAs are associated with lower fasting insulin concentrations, offering a beneficial effect on insulin sensitivity. SYSTEMATIC REVIEW REGISTRATION: PROSPERO registration number CRD42021257248.


Assuntos
Diabetes Mellitus Tipo 2 , Resistência à Insulina , Humanos , Diabetes Mellitus Tipo 2/prevenção & controle , Diabetes Mellitus Tipo 2/tratamento farmacológico , Insulina , Obesidade , Glucose , Ácidos Graxos Voláteis/uso terapêutico , Glicemia/análise
7.
J Gene Med ; 15(1): 28-41, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23293075

RESUMO

BACKGROUND: Type 1 diabetes (T1D) results from an autoimmune attack against the insulin-producing ß-cells of the pancreas. The present study aimed to reverse T1D by gene therapy. METHODS: We used a novel surgical technique, which involves isolating the liver from the circulation before the delivery of a lentiviral vector carrying furin-cleavable human insulin (INS-FUR) or empty vector to the livers of diabetic non-obese diabetic mice (NOD). This was compared with the direct injection of the vector into the portal circulation. Mice were monitored for body weight and blood glucose. Intravenous glucose tolerance tests were performed. Expression of insulin and pancreatic transcription factors was determined by the reverse transcriptase-polymerase chain reaction and immunohistochemistry and immunoelectron microscopy was used to localise insulin. RESULTS: Using the novel surgical technique, we achieved long-term transduction (42% efficiency) of hepatocytes, restored normoglycaemia for 150 days (experimental endpoint) and re-established normal glucose tolerance. We showed the expression of ß-cell transcription factors, murine insulin, glucagon and somatostatin, and hepatic storage of insulin in granules. The expression of hepatic markers, C/EBP-ß, G6PC, AAT and GLUI was down-regulated in INS-FUR-treated livers. Liver function tests remained normal, with no evidence of intrahepatic inflammation or autoimmune destruction of the insulin-secreting liver tissue. By comparison, direct injection of INS-FUR reduced blood glucose levels, and no pancreatic transdifferentiation or normal glucose tolerance was observed. CONCLUSIONS: This gene therapy protocol has, for the first time, permanently reversed T1D with normal glucose tolerance in NOD mice and, as such, represents a novel therapeutic strategy for the treatment of T1D.


Assuntos
Diabetes Mellitus Tipo 1/terapia , Terapia Genética/métodos , Fígado/metabolismo , Alanina Transaminase/sangue , Animais , Aspartato Aminotransferases/sangue , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Glicemia/análise , Transdiferenciação Celular/efeitos dos fármacos , Feminino , Furina/metabolismo , Vetores Genéticos , Glucagon/genética , Glucagon/metabolismo , Teste de Tolerância a Glucose , Hepatócitos/metabolismo , Proteína Homeobox Nkx-2.2 , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Insulina/biossíntese , Insulina/sangue , Células Secretoras de Insulina/metabolismo , Lentivirus/genética , Camundongos , Camundongos Endogâmicos NOD , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Análise de Sequência com Séries de Oligonucleotídeos , Fatores de Transcrição Box Pareados/genética , Fatores de Transcrição Box Pareados/metabolismo , Somatostatina/genética , Somatostatina/metabolismo , Transativadores/genética , Transativadores/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Transdução Genética , Proteínas de Peixe-Zebra
8.
Artigo em Inglês | MEDLINE | ID: mdl-36901213

RESUMO

The 21st century has brought a growing and significant focus on performance and health within the workforce, with the aim of improving the health and performance of the blue- and white-collar workforce. The present research investigated heart rate variability (HRV) and psychological performance between blue and white-collar workers to determine if differences were evident. A total of 101 workers (n = 48 white-collar, n = 53 blue-collar, aged 19-61 years) underwent a three lead electrocardiogram to obtain HRV data during baseline (10 min) and active (working memory and attention) phases. The Cambridge Neuropsychological Test Automated Battery, specifically the spatial working memory, attention switching task, rapid visual processing and the spatial span, were used. Differences in neurocognitive performance measures indicated that white-collar workers were better able to detect sequences and make less errors than blue-collar workers. The heart rate variability differences showed that white-collar workers exhibit lower levels of cardiac vagal control during these neuropsychological tasks. These initial findings provide some novel insights into the relationship between occupation and psychophysiological processes and further highlight the interactions between cardiac autonomic variables and neurocognitive performance in blue and white-collar workers.


Assuntos
Coração , Ocupações , Humanos , Frequência Cardíaca , Psicometria , Eletrocardiografia
9.
Cancers (Basel) ; 15(20)2023 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-37894321

RESUMO

The phosphatase and tensin homolog deleted on chromosome 10 (PTEN) is a well characterised tumour suppressor, playing a critical role in the maintenance of fundamental cellular processes including cell proliferation, migration, metabolism, and survival. Subtle decreases in cellular levels of PTEN result in the development and progression of cancer, hence there is tight regulation of the expression, activity, and cellular half-life of PTEN at the transcriptional, post-transcriptional, and post-translational levels. PTENP1, the processed pseudogene of PTEN, is an important transcriptional and post-transcriptional regulator of PTEN. PTENP1 expression produces sense and antisense transcripts modulating PTEN expression, in conjunction with miRNAs. Due to the high sequence similarity between PTEN and the PTENP1 sense transcript, the transcripts possess common miRNA binding sites with the potential for PTENP1 to compete for the binding, or 'sponging', of miRNAs that would otherwise target the PTEN transcript. PTENP1 therefore acts as a competitive endogenous RNA (ceRNA), competing with PTEN for the binding of specific miRNAs to alter the abundance of PTEN. Transcription from the antisense strand produces two functionally independent isoforms (PTENP1-AS-α and PTENP1-AS-ß), which can regulate PTEN transcription. In this review, we provide an overview of the post-transcriptional regulation of PTEN through interaction with its pseudogene, the cellular miRNA milieu and operation of the ceRNA network. Furthermore, its importance in maintaining cellular integrity and how disruption of this PTEN-miRNA-PTENP1 axis may lead to cancer but also provide novel therapeutic opportunities, is discussed. Precision targeting of PTENP1-miRNA mediated regulation of PTEN may present as a viable alternative therapy.

10.
Artigo em Inglês | MEDLINE | ID: mdl-35206374

RESUMO

The COVID-19 pandemic has incited a rise in anxiety, with uncertainty regarding the specific impacts and risk factors across multiple populations. A qualitative systematic review was conducted to investigate the prevalence and associations of anxiety in different sample populations in relation to the COVID-19 pandemic. Four databases were utilised in the search (Medline, EMBASE, CINAHL, and PsycINFO). The review period commenced in April 2021 and was finalised on 5 July 2021. A total of 3537 studies were identified of which 87 were included in the review (sample size: 755,180). Healthcare workers had the highest prevalence of anxiety (36%), followed by university students (34.7%), the general population (34%), teachers (27.2%), parents (23.3%), pregnant women (19.5%), and police (8.79%). Risk factors such as being female, having pre-existing mental conditions, lower socioeconomic status, increased exposure to infection, and being younger all contributed to worsened anxiety. The review included studies published before July 2021; due to the ongoing nature of the COVID-19 pandemic, this may have excluded relevant papers. Restriction to only English papers and a sample size > 1000 may have also limited the range of papers included. These findings identify groups who are most vulnerable to developing anxiety in a pandemic and what specific risk factors are most common across multiple populations.


Assuntos
COVID-19 , Ansiedade/epidemiologia , COVID-19/epidemiologia , Depressão/epidemiologia , Feminino , Humanos , Saúde Mental , Pandemias , Gravidez , SARS-CoV-2
11.
Cells ; 11(14)2022 07 08.
Artigo em Inglês | MEDLINE | ID: mdl-35883588

RESUMO

Type 1 diabetes is a chronic illness in which the native beta (ß)-cell population responsible for insulin release has been the subject of autoimmune destruction. This condition requires patients to frequently measure their blood glucose concentration and administer multiple daily exogenous insulin injections accordingly. Current treatments fail to effectively treat the disease without significant side effects, and this has led to the exploration of different approaches for its treatment. Gene therapy and the use of viral vectors has been explored extensively and has been successful in treating a range of diseases. The use of viral vectors to deliver ß-cell transcription factors has been researched in the context of type 1 diabetes to induce the pancreatic transdifferentiation of cells to replace the ß-cell population destroyed in patients. Studies have used various combinations of pancreatic and ß-cell transcription factors in order to induce pancreatic transdifferentiation and have achieved varying levels of success. This review will outline why pancreatic transcription factors have been utilised and how their application can allow the development of insulin-producing cells from non ß-cells and potentially act as a cure for type 1 diabetes.


Assuntos
Transdiferenciação Celular , Diabetes Mellitus Tipo 1 , Células Secretoras de Insulina , Transdiferenciação Celular/genética , Técnicas de Reprogramação Celular/métodos , Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 1/terapia , Humanos , Insulina , Fatores de Transcrição/genética
12.
J Oncol ; 2022: 2250407, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36532885

RESUMO

Background: Overexpression of sphingosine kinase 1 (SphK1) is casually associated with many types of cancer, and inhibitors of SphK1 sensitize tumors to chemotherapy. SphK1 is expressed as two major isoforms, SphK1a and SphK1b. To date, no information has been reported on the SphK1 isoform expression profile and its clinical relevance. Objective: The objective is to examine the expression profile of the SphK1a and SPhK1b isoforms in human cancer and noncancer tissues and cell lines and explore their clinical relevance. Methods: We used PCR to qualitatively examine the expression profile of these two isoforms in breast, liver, and prostate cancer tissues plus paired adjacent tissues and in 11 cancer and normal cell lines (breast, cervical, bone, prostate, colon, brain, mesothelioma tumor and benign, and human kidney cells). Results: We found that SphK1a was ubiquitously expressed in all cancer cells and tissues tested; in contrast, SphK1b was only expressed in selective cell types in breast, prostate, and lung cancer. Conclusions: Our data suggest that SphK1a is important for generic SphK1/S1P functions, and SphK1b mediates specialized and/or unique pathways in a specific type of tissue and could be a biomarker for cancer. This discovery is important for future SphK1-related cancer research and may have clinical implications in drug development associated with SphK1-directed cancer treatment.

13.
Hum Mol Genet ; 18(15): 2851-62, 2009 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-19457929

RESUMO

Germline and somatic PTEN mutations are found in Cowden syndrome (CS) and multiple sporadic malignancies, respectively. PTEN function appears to be modulated by subcellular compartmentalization, and mislocalization may affect function. We have shown that cellular ATP levels affect nuclear PTEN levels. Here, we examined the ATP-binding capabilities of PTEN and functional consequences, relevant to cancer-associated mutations. PTEN mutation analysis of CS patients and sporadic colorectal carcinomas and comparative aminoacid analysis were utilized to identify mutations in ATP-binding motifs. The ability of wild-type (WT) or mutant PTEN to bind ATP was assessed by ATP-agarose-binding assays. Subcellular fractionation, western blotting, confocal microscopy and growth assays were used to determine relative nuclear-cytoplasmic localization and function. Somatic colorectal carcinoma-derived PTEN missense mutations were associated with nuclear mislocalization. These mutations altered cellular proliferation, apoptosis and anchorage-dependent growth. Examination of PTEN's amino acid sequence revealed these mutations resided in previously undescribed ATP-binding motifs (c.60-73; c.122-136). In contrast to WT PTEN, both cancer-associated somatic and germline-derived PTEN missense mutations, which lie within the ATP-binding motifs, result in mutant PTEN that does not bind ATP efficiently. We also show that CS patients with germline ATP-binding motif-mutations had nuclear PTEN mislocalization. Of four unrelated patients with functional germline ATP-binding domain mutations, all three female patients had breast cancers. Germline and somatic mutations within PTEN's ATP-binding domain play important pathogenic roles in both heritable and sporadic carcinogenesis by PTEN nuclear mislocalization resulting in altered signaling and growth. Manipulation of ATP may represent novel therapies in tumors with such PTEN alterations.


Assuntos
Trifosfato de Adenosina/metabolismo , Síndrome do Hamartoma Múltiplo/genética , Mutação , PTEN Fosfo-Hidrolase/genética , PTEN Fosfo-Hidrolase/metabolismo , Motivos de Aminoácidos , Sequência de Aminoácidos , Linhagem Celular Tumoral , Feminino , Mutação em Linhagem Germinativa , Síndrome do Hamartoma Múltiplo/metabolismo , Humanos , Masculino , Dados de Sequência Molecular , PTEN Fosfo-Hidrolase/química , Ligação Proteica , Transporte Proteico , Alinhamento de Sequência
14.
Methods Mol Biol ; 2324: 165-185, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34165715

RESUMO

PTENP1 is a processed pseudogene of the tumour suppressor phosphatase and tensin homolog deleted on chromosome 10 (PTEN). It functions posttranscriptionally to regulate PTEN by acting as a sponge for microRNAs that target PTEN. PTENP1 therefore functions as a competitive endogenous RNA (ceRNA), competing with PTEN for binding of microRNAs (miRNA) and thereby modulating PTEN cellular abundance. Studies of the overexpression of PTENP1 all confirm its oncosuppressive function to be mediated through the suppression of cell proliferation, induction of apoptosis, and inhibition of cell migration and invasion of cancer cells of differing types. These oncosuppressive functions are a direct consequence of miRNA binding by PTENP1 and the subsequent liberation of PTEN from miRNA induced suppression. In this chapter, we will focus initially on the description of a high efficiency transient transfection method to introduce and overexpress PTENP1 in the cell type of interest, followed by accurate methodologies to measure transfection efficiency by flow cytometry. We will then continue to describe two methods to analyze cell proliferation, namely the CCK-8 assay and Click-iT® EdU assay. Due to commonalities in the manifestation of the oncosuppressive effects of PTENP1, mediated through its role as a ceRNA, the methods presented in this chapter will have wide applicability to a variety of different cell types.


Assuntos
MicroRNAs/genética , PTEN Fosfo-Hidrolase/metabolismo , Pseudogenes , Proteínas Supressoras de Tumor/agonistas , Regiões 3' não Traduzidas/genética , Animais , Ligação Competitiva , Contagem de Células , Divisão Celular , Linhagem Celular Tumoral , Clonagem Molecular/métodos , Colorimetria/métodos , Replicação do DNA , Citometria de Fluxo/métodos , Corantes Fluorescentes , Humanos , Microscopia de Fluorescência , PTEN Fosfo-Hidrolase/genética , Plasmídeos/genética , Pseudogenes/genética , Coloração e Rotulagem/métodos , Transfecção/métodos , Proteínas Supressoras de Tumor/genética , Proteínas Supressoras de Tumor/metabolismo
15.
STAR Protoc ; 2(4): 100910, 2021 12 17.
Artigo em Inglês | MEDLINE | ID: mdl-34746868

RESUMO

MicroRNAs (miRNAs) are elements of the gene regulatory network and manipulating their abundance is essential toward elucidating their role in patho-physiological conditions. We present a detailed workflow that identifies important miRNAs using a machine learning algorithm. We then provide optimized techniques to validate the identified miRNAs through over-expression/loss-of-function studies. Overall, these protocols apply to any field in biology where high-dimensional data are produced. For complete details on the use and execution of this protocol, please refer to Wong et al. (2021a).


Assuntos
Perfilação da Expressão Gênica/métodos , Aprendizado de Máquina , MicroRNAs/genética , Transcriptoma/genética , Algoritmos , Técnicas de Cultura de Células/métodos , Células Cultivadas , Técnicas de Silenciamento de Genes , Redes Reguladoras de Genes/genética , Humanos , Ilhotas Pancreáticas/citologia , Fluxo de Trabalho
16.
Physiol Meas ; 41(9): 095001, 2020 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-33021231

RESUMO

OBJECTIVE: To investigate the relationship between EEG activity and the global and domain specific cognitive performance of healthy nurses, and determine the predictive capabilities of these relationships. APPROACH: Sixty-four nurses were recruited for the present study, and data from 61 were utilised in the present analysis. Global and domain specific cognitive performance of each participant was assessed psychometrically using the Mini-mental state exam and the Cognistat, and a 32-lead monopolar EEG was recorded during a resting baseline phase and an active phase in which participants completed the Stroop test. MAIN RESULTS: Global cognitive performance was successfully predicted (81%-85% of variance) by a combination of fast wave activity variables in the alpha, beta and theta frequency bands. Interestingly, predicting domain specific performance had varying degrees of success (42%-99% of the variance predicted) and relied on combinations of both slow and fast wave activity, with delta and gamma activity predicting attention performance; delta, theta, and gamma activity predicting memory performance; and delta and beta variables predicting judgement performance. SIGNIFICANCE: Global and domain specific cognitive performance of Australian nurses may be predicted with varying degrees of success by a unique combination of EEG variables. These proposed models image transitory cognitive declines and as such may prove useful in the prediction of early cognitive impairment, and may enable better diagnosis, and management of cognitive impairment.


Assuntos
Cognição , Eletroencefalografia , Enfermeiras e Enfermeiros , Austrália , Disfunção Cognitiva/diagnóstico , Humanos , Teste de Stroop
17.
Artigo em Inglês | MEDLINE | ID: mdl-31615872

RESUMO

Germline alterations of the tumor suppressor PTEN have been extensively characterized in patients with PTEN hamartoma tumor syndromes, encompassing subsets of Cowden syndrome, Bannayan-Riley-Ruvalcaba syndrome, Proteus and Proteus-like syndromes, as well as autism spectrum disorder. Studies have shown an increase in the risk of developing specific cancer types in the presence of a germline PTEN mutation. Furthermore, outside of the familial setting, somatic variants of PTEN occur in numerous malignancies. Here we introduce and discuss the prospect of moving toward a systems pathology approach for PTEN diagnostics, incorporating clinical and molecular pathology data with the goal of improving the clinical management of patients with a PTEN mutation. Detection of a germline PTEN mutation can inform cancer surveillance and in the case of somatic mutation, have value in predicting disease course. Given that PTEN functions in the PI3K/AKT/mTOR pathway, identification of a PTEN mutation may highlight new therapeutic opportunities and/or inform therapeutic choices.


Assuntos
Neoplasias/genética , PTEN Fosfo-Hidrolase/genética , Transtorno do Espectro Autista/genética , Biomarcadores Tumorais/genética , Genes Supressores de Tumor , Testes Genéticos , Mutação em Linhagem Germinativa , Síndrome do Hamartoma Múltiplo/genética , Terapia de Alvo Molecular/métodos , PTEN Fosfo-Hidrolase/metabolismo , Fosfatidilinositol 3-Quinases
18.
Cells ; 9(10)2020 10 02.
Artigo em Inglês | MEDLINE | ID: mdl-33023100

RESUMO

Previously, we used a lentiviral vector to deliver furin-cleavable human insulin (INS-FUR) to the livers in several animal models of diabetes using intervallic infusion in full flow occlusion (FFO), with resultant reversal of diabetes, restoration of glucose tolerance and pancreatic transdifferentiation (PT), due to the expression of beta (ß)-cell transcription factors (ß-TFs). The present study aimed to determine whether we could similarly reverse diabetes in the non-obese diabetic (NOD) mouse using an adeno-associated viral vector (AAV) to deliver INS-FUR ± the ß-TF Pdx1 to the livers of diabetic mice. The traditional AAV8, which provides episomal expression, and the hybrid AAV8/piggyBac that results in transgene integration were used. Diabetic mice that received AAV8-INS-FUR became hypoglycaemic with abnormal intraperitoneal glucose tolerance tests (IPGTTs). Expression of ß-TFs was not detected in the livers. Reversal of diabetes was not achieved in mice that received AAV8-INS-FUR and AAV8-Pdx1 and IPGTTs were abnormal. Normoglycaemia and glucose tolerance were achieved in mice that received AAV8/piggyBac-INS-FUR/FFO. Definitive evidence of PT was not observed. This is the first in vivo study using the hybrid AAV8/piggyBac system to treat Type 1 diabetes (T1D). However, further development is required before the system can be used for gene therapy of T1D.


Assuntos
Diabetes Mellitus Experimental/genética , Terapia Genética/métodos , Insulina/metabolismo , Animais , Humanos , Camundongos , Camundongos Endogâmicos NOD
20.
Biomark Insights ; 13: 1177271918786931, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30038486

RESUMO

BACKGROUND: Heart rate variability (HRV) is a non-invasive measure of the function of the autonomic nervous system, and its dynamic nature may provide a means through which stroke and its associated complications may be predicted, monitored, and managed. OBJECTIVE: The objective of this review is to identify and provide a critique on the most recent uses of HRV in stroke diagnosis/management and highlight areas that warrant further research. METHODS: The MEDLINE, CINAHL, and OVID MEDLINE databases were canvassed using a systematic search strategy, for articles investigating the use of HRV in stroke diagnosis and management. Initial paper selections were based on title alone, and final paper inclusion was informed by a full-text critical appraisal. RESULTS: The systematic search returned 98 records, of which 51 were unique. Following screening, 22 records were included in the final systematic review. The included papers provided some information regarding predicting incident stroke, which largely seems to be best predicted by time- and frequency-domain HRV parameters. Furthermore, post-stroke complications and functionality are similarly predicted by time- and frequency-domain parameters, as well as non-linear parameters in some instances. CONCLUSIONS: Current research provides good evidence that HRV parameters may have utility as a biomarker for stroke and for post-stroke complications and/or functionality. Future research would benefit from the integration of non-linear, and novel parameters, the hybridisation of HRV parameters, and the expansion of the utilisation of predictive regression and hazard modelling.

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