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1.
Blood ; 141(5): 503-518, 2023 02 02.
Artigo em Inglês | MEDLINE | ID: mdl-35981563

RESUMO

T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive and often incurable disease. To uncover therapeutic vulnerabilities, we first developed T-ALL patient-derived tumor xenografts (PDXs) and exposed PDX cells to a library of 433 clinical-stage compounds in vitro. We identified 39 broadly active drugs with antileukemia activity. Because endothelial cells (ECs) can alter drug responses in T-ALL, we developed an EC/T-ALL coculture system. We found that ECs provide protumorigenic signals and mitigate drug responses in T-ALL PDXs. Whereas ECs broadly rescued several compounds in most models, for some drugs the rescue was restricted to individual PDXs, suggesting unique crosstalk interactions and/or intrinsic tumor features. Mechanistically, cocultured T-ALL cells and ECs underwent bidirectional transcriptomic changes at the single-cell level, highlighting distinct "education signatures." These changes were linked to bidirectional regulation of multiple pathways in T-ALL cells as well as in ECs. Remarkably, in vitro EC-educated T-ALL cells transcriptionally mirrored ex vivo splenic T-ALL at single-cell resolution. Last, 5 effective drugs from the 2 drug screenings were tested in vivo and shown to effectively delay tumor growth and dissemination thus prolonging overall survival. In sum, we developed a T-ALL/EC platform that elucidated leukemia-microenvironment interactions and identified effective compounds and therapeutic vulnerabilities.


Assuntos
Células Endoteliais , Leucemia-Linfoma Linfoblástico de Células T Precursoras , Humanos , Células Endoteliais/metabolismo , Leucemia-Linfoma Linfoblástico de Células T Precursoras/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células T Precursoras/metabolismo , Comunicação Celular , Técnicas de Cocultura , Microambiente Tumoral
2.
Artigo em Inglês | MEDLINE | ID: mdl-39350506

RESUMO

Sex differences in patterns of cortical thickness and neuropsychiatric symptom (NPS) burden were examined among individuals with Alzheimer's disease (AD) and two copies (homozygote carriers) of the e4 allele of the apolipoprotein gene (APOE). A total of 752 participants with a clinical etiologic diagnosis of AD were selected from the National Alzheimer's Coordinating Center (NACC) database. Bayesian multilevel regression was used to examine both the within- and between-sex differences in gray-matter cortical thickness and total NPS burden associated with APOE homozygosity. Female homozygote carriers displayed a high probability of having reduced cortical thickness primarily in medial-lateral temporal regions and a greater burden of NPS, relative to both non-homozygous females and homozygous males. These findings support the notion that APOE4 status affects cortical thickness and symptom burden in men and women with AD differentially, with females showing more pronounced effects in brain areas known to be vulnerable in early AD. Future investigations should attempt to elucidate the proposed pattern of decline longitudinally.

3.
New Phytol ; 240(2): 757-769, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37518950

RESUMO

Mitragynine, an analgesic alkaloid from the plant Mitragyna speciosa (kratom), offers a safer alternative to clinical opioids such as morphine, owing to its more favorable side effect profile. Although kratom has been traditionally used for stimulation and pain management in Southeast Asia, the mitragynine biosynthesis pathway has remained elusive. We embarked on a search for mitragynine biosynthetic genes from the transcriptomes of kratom and other members of the Rubiaceae family. We studied their functions in vitro and in vivo. Our investigations led to the identification of several reductases and an enol methyltransferase that forms a new clade within the SABATH methyltransferase family. Furthermore, we discovered a methyltransferase from Hamelia patens (firebush), which catalyzes the final step. With the tryptamine 4-hydroxylase from the psychedelic mushroom Psilocybe cubensis, we accomplished the four-step biosynthesis for mitragynine and its stereoisomer, speciogynine in both yeast and Escherichia coli when supplied with tryptamine and secologanin. Although we have yet to pinpoint the authentic hydroxylase and methyltransferase in kratom, our discovery completes the mitragynine biosynthesis. Through these breakthroughs, we achieved the microbial biosynthesis of kratom opioids for the first time. The remarkable enzyme promiscuity suggests the possibility of generating derivatives and analogs of kratom opioids in heterologous systems.


Assuntos
Mitragyna , Alcaloides de Triptamina e Secologanina , Analgésicos Opioides , Mitragyna/genética , Extratos Vegetais , Triptaminas , Oxigenases de Função Mista
4.
J Neural Transm (Vienna) ; 130(10): 1303-1313, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37584690

RESUMO

Suicide is a significant public health crisis, with 800,000 people dying annually. Most people completing suicide have previous psychiatric conditions, and those with psychotic and mood disorders are particularly vulnerable. Unfortunately, there are currently no biomarkers available for accurately detecting suicidal ideation. Given the genetic and environmental factors that play a role in suicidal ideation, we attempted to determine epigenetic modifications, specifically DNA methylation, in response to changes in suicidal ideation. Using a longitudinal study design, 31 participants with schizophrenia spectrum disorders were interviewed at a baseline visit and again at a follow-up visit 3-12 months later. Current suicidal ideation was recorded at both visits with the Columbia Suicide Severity Rating Scale and the Beck Scale for Suicide Ideation, and whole blood was collected for methylation analysis. Our analysis shows a significant negative correlation between cg26910920 methylation and increasing Columbia Suicide Severity Rating Scale scores and a positive correlation between cg13673029 methylation and increasing Beck Scale for Suicide Ideation scores. This pilot study indicates that there is  the possibility  that DNA methylation can respond to changes in suicidal ideation over time and potentially be used as a biomarker of suicidal ideation in the future.


Assuntos
Esquizofrenia , Humanos , Esquizofrenia/genética , Ideação Suicida , Tentativa de Suicídio/psicologia , Estudos Longitudinais , Metilação , Projetos Piloto , Biomarcadores , Escalas de Graduação Psiquiátrica
5.
J Neural Transm (Vienna) ; 130(2): 165-169, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36648581

RESUMO

Various studies have investigated the relationship between genetic polymorphisms of antipsychotic drug-metabolizing agents and drug response. DNA methylation is a form of epigenetic modification that regulates gene expression. Few studies have analyzed the relationship between genome-wide methylation patterns and treatment resistance schizophrenia. The primary aim of this pilot study is to investigate the association between treatment resistance status and genome-wide DNA methylation in schizophrenia patients. Treatment resistance status was determined for 109 patients with schizophrenia. Treatment resistance was the primary outcome variable in a model, including methylation status of white blood cells using the Illumina 450 array. The genome-wide DNA methylation levels in 109 Schizophrenia subjects did not show that DNA methylation sties were associated with resistance status. From our study, it is evident the importance of continuing to investigate the relationship between DNA methylation and antipsychotic response to personalize treatment in schizophrenia. Future studies require larger prescription databases to build on the results presented in this pilot study.


Assuntos
Antipsicóticos , Esquizofrenia , Humanos , Esquizofrenia/tratamento farmacológico , Esquizofrenia/genética , Esquizofrenia Resistente ao Tratamento , Projetos Piloto , Metilação de DNA , Epigênese Genética , Antipsicóticos/uso terapêutico , Estudo de Associação Genômica Ampla
6.
Neuropsychobiology ; : 54-59, 2023 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-37984346

RESUMO

INTRODUCTION: An increased proclivity towards violence is often associated with those diagnosed with schizophrenia (SCZ), despite contradictory findings from prior studies exploring the association between violence and SCZ. Evidence has shown that certain comorbidities, specifically the presence of a substance use disorders, can result in increased aggression in those with SCZ. Copy number variation (CNV) load has also previously been implicated in the genetic vulnerability of individuals with SCZ. For this study, we aimed to determine whether CNV load correlates with increased violence in SCZ. METHODS: Community-dwelling patients diagnosed with SCZ spectrum disorders (n = 203) were recruited from a non-forensic population. The assessment for aggression was completed using a cross-sectional and retrospective design, and CNV analysis was conducted analysing genomic DNA using the Illumina Omni 2.5 array. RESULTS: No correlation between the number of CNV events (either deletion or duplication) and the severity of the physical violence episode index was found. However, there was a significant association between larger deletion events across the violent behaviours under investigation. DISCUSSION: These results need to be confirmed in more extensive studies using standardized tools developed for non-forensic populations, such as the Brown-Goodwin Scale of Aggression.

7.
Artigo em Inglês | MEDLINE | ID: mdl-37420032

RESUMO

Schizophrenia (SCZ) is a severe psychotic disorder associated with premature mortality and aging. Moreover, the symptoms and progression of psychiatric disorders in general are associated with decreased lifespan, biological aging, and poorer medical outcomes. In this study, we investigated the relationship between several epigenetic clocks and scanned the entire genome for association in a cohort of SCZ individuals (n = 107). Biological age was computed from blood DNA methylation (DNAm) and tested for association against  common  variants across the genome using general linear models. Genes affecting epigenetic age acceleration in our cohort were found mainly when using the telomeric length clock rather than the other biological clocks. These findings pair with existing evidence that there are some genes associated with longevity and suggest further investigations of  putative biological mechanisms for morbidity and premature mortality, not only in patients with SCZ but also in the general population.

8.
Psychiatry Clin Neurosci ; 77(1): 2-11, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36165228

RESUMO

AIM: Validating the vulnerabilities and pathologies underlying treatment-resistant schizophrenia (TRS) is an important challenge in optimizing treatment. Gyrification and surface area (SA), reflecting neurodevelopmental features, have been linked to genetic vulnerability to schizophrenia. The aim of this study was to identify gyrification and SA abnormalities specific to TRS. METHODS: We analyzed 3T magnetic resonance imaging findings of 24 healthy controls (HCs), 20 responders to first-line antipsychotics (FL-Resp), and 41 patients with TRS, including 19 clozapine responders (CLZ-Resp) and 22 FL- and clozapine-resistant patients (patients with ultratreatment-resistant schizophrenia [URS]). The local gyrification index (LGI) and associated SA were analyzed across groups. Diagnostic accuracy was verified by receiver operating characteristic curve analysis. RESULTS: Both CLZ-Resp and URS had lower LGI values than HCs (P = 0.041, Hedges g [gH ] = 0.75; P = 0.013, gH  = 0.96) and FL-Resp (P = 0.007, gH  = 1.00; P = 0.002, gH  = 1.31) in the left medial parietal cortex (Lt-MPC). In addition, both CLZ-Resp and URS had lower SA in the Lt-MPC than FL-Resp (P < 0.001, gH  = 1.22; P < 0.001, gH  = 1.75). LGI and SA were positively correlated in non-TRS (FL-Resp) (ρ = 0.64, P = 0.008) and TRS (CLZ-Resp + URS) (ρ = 0.60, P < 0.001). The areas under the receiver operating characteristic curve for non-TRS versus TRS with LGI and SA in the Lt-MPC were 0.79 and 0.85, respectively. SA in the Lt-MPC was inversely correlated with negative symptoms (ρ = -0.40, P = 0.018) and clozapine plasma levels (ρ = -0.35, P = 0.042) in TRS. CONCLUSION: LGI and SA in the Lt-MPC, a functional hub in the default-mode network, were abnormally reduced in TRS compared with non-TRS. Thus, altered LGI and SA in the Lt-MPC might be structural features associated with genetic vulnerability to TRS.


Assuntos
Clozapina , Esquizofrenia , Humanos , Esquizofrenia/diagnóstico por imagem , Esquizofrenia/tratamento farmacológico , Esquizofrenia/patologia , Clozapina/farmacologia , Clozapina/uso terapêutico , Lobo Parietal , Imageamento por Ressonância Magnética , Esquizofrenia Resistente ao Tratamento , Córtex Cerebral
9.
J Neural Transm (Vienna) ; 129(1): 105-114, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34966975

RESUMO

DNA methylation analysis at the genome-wide level is a useful tool to explore potential sex differences in SCZ patients. The primary aim of the current study was to identify differentially methylated regions of DNA between males and females with schizophrenia. We collected DNA samples from 134 schizophrenia patients to measure genome-wide methylation at single-base resolution in 96 males and 38 females. We further repeated the analysis in 13 subjects (9 females, 4 males) to confirm the sex differences and to reduce the effect of potential confounders. The longitudinal methylation analysis found significant replication of several genes across the genome. These genes included RFTN1, TLE1, DAZL, PRR4, UTP14C, RNU12, and LOC644649. The overall results showed robust association between autosomal CpG sites and sex. Longitudinal methylation analysis can be used as internal replication to confirm epigenetic variants that are stable over time.


Assuntos
Esquizofrenia , Ilhas de CpG , Metilação de DNA , Epigenoma , Feminino , Estudo de Associação Genômica Ampla/métodos , Humanos , Masculino , Esquizofrenia/genética , Caracteres Sexuais
10.
Pharmacopsychiatry ; 55(4): 211-219, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35483870

RESUMO

INTRODUCTION: The relationship between genetic polymorphisms of antipsychotic drug-metabolizing agents and drug receptors has been often investigated. DNA methylation is a form of epigenetic modification that regulates gene expression. Few studies have analyzed the relationship between genome-wide methylation patterns and antipsychotic dosage. The primary aim of this pilot study was to investigate the association between antipsychotic dosage and genome-wide DNA methylation in patients with schizophrenia (SCZ). METHODS: Current dosage of antipsychotic medications was assessed in 136 patients with SCZ. Dosage was standardized using three different methods: chlorpromazine equivalent dose (CPZe), defined daily dose (DDD), and percentage of Lexicomp maximum dose (PM%). DNA methylation was measured in white blood cells. Antipsychotic dosage was the primary outcome variable in a model, including genome-wide methylation status as the main predictor. RESULTS: This study did not show any association between DNA methylation and dosage variation for CPZe, PM%, and DDD. However, the probe cg271403389 was consistently associated with antipsychotic dosage across the three standardization methods. When looking at the genomic location of the most significant probes, we found that 15% were intergenic, 23% were in the distal promoter, 9% in the 3'untranslated region, 32% in the gene body, 3% in the 5' untranslated region, 15% in the proximal promoter, and 3% in the first exon. DISCUSSION: This study shows the importance of investigating the relationship between DNA methylation and optimal antipsychotic dosage to personalize treatment in SCZ. Future studies require larger prescription databases to build on the results of this analysis.


Assuntos
Antipsicóticos , Antipsicóticos/uso terapêutico , Metilação de DNA/genética , Descoberta de Drogas , Epigênese Genética , Humanos , Projetos Piloto
11.
J Nerv Ment Dis ; 210(2): 111-115, 2022 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-34618715

RESUMO

ABSTRACT: Half of patients with schizophrenia experience suicidal ideation. Only few studies have examined the effects of recent stress on both current and emergent suicidal ideation.A cohort of 85 patients with schizophrenia spectrum disorders was assessed. The study was divided into a cross-sectional and longitudinal arms to test the effect of recent stress on suicidal ideation. Analysis was done using logistic regression models.After correcting for covariates, recent stress had no significant effect on current suicidal ideation. However, increased total stress (odds ratio [OR] = 1.099 [1.032-1.170], p = 0.003) and health-related stress (OR = 1.331 [1.074-1.650], p = 0.009) at follow-up were predictive of emergent suicidal ideation.With this sample size, we were unable to draw firm conclusions regarding the effect of specific life events on suicidal ideation. Further studies involving larger samples that investigate the interplay between several risk factors are needed.


Assuntos
Acontecimentos que Mudam a Vida , Psicologia do Esquizofrênico , Estresse Psicológico , Ideação Suicida , Adulto , Estudos Transversais , Feminino , Seguimentos , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Suicídio/psicologia , Tentativa de Suicídio/psicologia , Adulto Jovem
12.
Psychiatry Clin Neurosci ; 76(11): 587-594, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36111425

RESUMO

BACKGROUND: Gamma-Aminobutyric Acid (GABA) is the primary inhibitory neurotransmitter in the central nervous system. GABAergic dysfunction has been implicated in the pathophysiology of schizophrenia. Clozapine, the only approved drug for treatment-resistant schizophrenia (TRS), involves the GABAergic system as one of its targets. However, no studies have investigated the relationship between brain GABA levels, as measured by proton magnetic resonance spectroscopy (1 H-MRS), and clozapine response in patients with TRS. METHODS: This study enrolled patients with TRS who did not respond to clozapine (ultra-resistant schizophrenia: URS) and who responded to clozapine (non-URS), patients with schizophrenia who responded to first-line antipsychotics (first-line responders: FLR), and healthy controls (HCs). We measured GABA levels in the midcingulate cortex (MCC) using 3T 1 H-MRS and compared these levels among the groups. The associations between GABA levels and symptom severity were also explored within the patient groups. RESULTS: A total of 98 participants (URS: n = 22; non-URS: n = 25; FLR: n = 16; HCs: n = 35) completed the study. We found overall group differences in MCC GABA levels (F(3,86) = 3.25, P = 0.04). Specifically, patients with URS showed higher GABA levels compared to those with non-URS (F(1,52) = 8.40, P = 0.03, Cohen's d = 0.84). MCC GABA levels showed no associations with any of the symptom severity scores within each group or the entire patient group. CONCLUSION: Our study is the first to report elevated GABA levels in the MCC in patients with schizophrenia resistant to clozapine treatment compared with those responsive to clozapine. Longitudinal studies are required to evaluate if GABA levels are a suitable biomarker to predict clozapine resistance.


Assuntos
Clozapina , Esquizofrenia , Humanos , Clozapina/farmacologia , Clozapina/uso terapêutico , Espectroscopia de Prótons por Ressonância Magnética/métodos , Esquizofrenia/diagnóstico por imagem , Esquizofrenia/tratamento farmacológico , Esquizofrenia Resistente ao Tratamento , Ácido gama-Aminobutírico
13.
Neuropsychobiology ; 80(5): 393-400, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33601401

RESUMO

BACKGROUND: Studies have shown that the overall copy number variant (CNV) load is associated with schizophrenia. Schizophrenia is a mental disorder that is frequently associated with suicidal behavior. METHODS: We recruited 263 patients with schizophrenia from the Centre for Addiction and Mental Health. The Columbia Suicide Severity Rating Scale was used to assess the presence of lifetime suicide attempt. Genotyping was completed using the Illumina Omni 2.5 chip. We tested the association between deletion events on chromosome 22 with suicide attempt in our schizophrenia sample. RESULTS: There was no significant difference between suicide attempters and non-attempters considering the presence/absence of deletion events on chromosome 22. CONCLUSION: Although our results did not show a significant association between deletions on chromosome 22 and suicide attempt in schizophrenia, CNV studies may reveal important, novel insights and open further investigation for the treatment of neuropsychiatric diseases.


Assuntos
Transtornos Psicóticos , Esquizofrenia , Cromossomos Humanos Par 22 , Humanos , Esquizofrenia/genética , Ideação Suicida , Tentativa de Suicídio
14.
Ann Vasc Surg ; 77: e7-e13, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34454017

RESUMO

The Mediterranean Federation for the Advancing of Vascular Surgery (MeFAVS) was founded in 2018, with the aim to promote cooperation among vascular professionals within Mediterranean countries. Due to its prominent social and economic impact on national health systems, diabetic peripheral artery was selected as the very first topic to be investigated by the federation. In this second paper, different experiences from delegates of participating countries were shared to define common strategies to harmonize, standardize, and optimize education and training in the Vascular Surgery specialty.


Assuntos
Angiopatias Diabéticas/cirurgia , Educação de Pós-Graduação em Medicina , Internato e Residência , Doença Arterial Periférica/cirurgia , Cirurgiões/educação , Procedimentos Cirúrgicos Vasculares/educação , Competência Clínica , Currículo , Angiopatias Diabéticas/diagnóstico , Angiopatias Diabéticas/epidemiologia , Humanos , Curva de Aprendizado , Região do Mediterrâneo/epidemiologia , Doença Arterial Periférica/diagnóstico , Doença Arterial Periférica/epidemiologia , Avaliação de Programas e Projetos de Saúde , Especialização
15.
Proc Natl Acad Sci U S A ; 120(1): e2218838120, 2023 01 03.
Artigo em Inglês | MEDLINE | ID: mdl-36574687

Assuntos
Cocaína , Plantas
16.
Proc Natl Acad Sci U S A ; 115(12): 3180-3185, 2018 03 20.
Artigo em Inglês | MEDLINE | ID: mdl-29511102

RESUMO

Monoterpenoid indole alkaloids (MIAs) possess a diversity of alkaloid skeletons whose biosynthesis is poorly understood. A bioinformatic search of candidate genes, combined with their virus-induced gene silencing, targeted MIA profiling and in vitro/in vivo pathway reconstitution identified and functionally characterized six genes as well as a seventh enzyme reaction required for the conversion of 19E-geissoschizine to tabersonine and catharanthine. The involvement of pathway intermediates in the formation of four MIA skeletons is described, and the role of stemmadenine-O-acetylation in providing necessary reactive substrates for the formation of iboga and aspidosperma MIAs is described. The results enable the assembly of complex dimeric MIAs used in cancer chemotherapy and open the way to production of many other biologically active MIAs that are not easily available from nature.


Assuntos
Carbolinas/metabolismo , Catharanthus/metabolismo , Alcaloides Indólicos/metabolismo , Proteínas de Plantas/genética , Aspidosperma/genética , Aspidosperma/metabolismo , Catharanthus/genética , Enzimas/genética , Enzimas/metabolismo , Regulação da Expressão Gênica de Plantas , Inativação Gênica , NADP/metabolismo , Proteínas de Plantas/metabolismo , Quinolinas/metabolismo , Strychnos/metabolismo , Tabernaemontana/metabolismo , Alcaloides de Vinca/metabolismo
17.
Drug Dev Res ; 82(5): 678-684, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-32394511

RESUMO

Tardive dyskinesia (TD) is a potentially irreversible movement disorder observed following long-term antipsychotic exposure. Its cause is unknown; however, a genetic component has been supported by studies of affected families. Dysbindin-1, encoded by the dystrobrevin-binding protein 1 DTNBP1 gene, has been associated with schizophrenia and is potentially involved in dopamine neurotransmission through its regulation of dopamine release and dopamine D2 receptor recycling, making it a candidate for investigation in TD. We investigated common variants across the DTNBP1 gene in our schizophrenia/patients with schizoaffective disorder of European ancestry. We found a number of DTNBP1 three-marker haplotypes to be associated with TD occurrence and TD severity (p < 0.05). These preliminary findings, if replicated in larger independent samples, would suggest that drugs targeting dysbindin-1 may be an option in the prevention and treatment of TD.


Assuntos
Disbindina/genética , Esquizofrenia/tratamento farmacológico , Esquizofrenia/genética , Discinesia Tardia/induzido quimicamente , Discinesia Tardia/genética , Adulto , Feminino , Predisposição Genética para Doença , Genótipo , Haplótipos , Humanos , Masculino
18.
Plant J ; 97(2): 257-266, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30256480

RESUMO

The important anticancer drugs, vinblastine, vincristine and analogs, are composed of the monoterpenoid indole alkaloids (MIAs), catharanthine and vindoline, found uniquely in the medicinal plant, Catharanthus roseus. While 26 genes involved in the assembly of these two MIAs are known, two key reactions have eluded characterization to complete the documentation of the vinblastine pathway in this plant species. The assembly of these dimeric MIAs requires O-acetylstemmadenine oxidase (ASO) and a dual function geissoschizine synthase (GS) that reduces cathenamine to form geissoschizine, and that also reduces the ASO product to form a common intermediate for subsequent conversion by four separate hydrolases to catharanthine, tabersonine or vincadifformine, respectively. The in planta role of ASO is supported by identifying a single amino acid-substituted ASO mutant with very low enzyme activity and by virus-induced gene silencing of ASO to produce plants that accumulate O-acetylstemmadenine rather than catharanthine and vindoline found in wild-type (WT) plants. The in planta role of GS is supported by showing that a low GS-expressing mutant accumulating lower levels of catharanthine and vindoline also displays significantly lower tabersonine-forming activity in coupled enzyme assays than in the WT background. Gene expression analyses demonstrate that both ASO and GS are highly enriched in the leaf epidermis where the pathways for catharanthine and tabersonine biosynthesis are expressed. The full elucidation of this canonical pathway enables synthetic biology approaches for manufacturing a broad range of MIAs, including these dimers used in cancer treatment.


Assuntos
Antineoplásicos Fitogênicos/metabolismo , Catharanthus/genética , Proteínas de Plantas/metabolismo , Alcaloides de Triptamina e Secologanina/metabolismo , Vimblastina/metabolismo , Vincristina/metabolismo , Carbolinas/metabolismo , Catharanthus/metabolismo , Alcaloides Indólicos/metabolismo , Engenharia Metabólica , Oxirredutases/genética , Oxirredutases/metabolismo , Proteínas de Plantas/genética , Plantas Medicinais , Biologia Sintética , Vimblastina/análogos & derivados , Alcaloides de Vinca/metabolismo
19.
Plant J ; 99(4): 626-636, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31009114

RESUMO

The biological activity of monoterpenoid indole alkaloids (MIAs) has led to their use in cancer treatment and other medical applications. Their biosynthesis has involved the formation of reactive intermediates by responsible enzymes to elaborate several different chemical scaffolds. Modification of scaffolds through different substitution reactions has produced chemically diverse MIAs and related biological activities. The present study characterizes the three-step pathway involved in the formation of (+)-echitovenine, the major O-acetylated MIA of Catharanthus roseus roots, and differentiates it from a parallel pathway involved in the formation of hörhammericine. Separate hydrolases convert a common reactive MIA intermediate to aspidosperma skeletons of opposite specific rotations, that is (+)-vincadifformine and (-)-tabersonine, respectively. The formation of (+) minovincinine from (+) vincadifformine 19-hydroxylase (V19H) is catalyzed by a root-specific cytochrome P450 with high amino acid sequence similarity to the leaf-specific tabersonine-3-hydroxylase involved in vindoline biosynthesis. Similarly, O-acetylation of (+)-minovincinine to form (+) echitovenine involves minovincinine-O-acetytransferase. The substrate specificity of V19H and MAT for their respective (+)-enantiomers defines the separate enantiomer-specific pathway involved in (+)-echitovenine biosynthesis and differentiates it from a parallel (-)-enantiomer-specific pathway involved in the formation of hörhammericine from (-)-tabersonine.


Assuntos
Alcaloides/metabolismo , Catharanthus/metabolismo , Alcaloides Indólicos/metabolismo , Quinolinas/metabolismo , Alcaloides de Triptamina e Secologanina/metabolismo , Alcaloides/química , Regulação da Expressão Gênica de Plantas , Alcaloides Indólicos/química , Folhas de Planta/metabolismo , Proteínas de Plantas/metabolismo , Raízes de Plantas/metabolismo , Quinolinas/química , Alcaloides de Triptamina e Secologanina/química
20.
J Neural Transm (Vienna) ; 127(9): 1315-1322, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32661777

RESUMO

In this study, we investigate the epigenetic mechanisms associated with current suicidal ideation. Gene expression changes have been found in post-mortem brain of suicide victims. However, it is not clear how in-vivo gene expression change confers risk for suicide. DNA methylation is a form of epigenetic modification that regulates gene expression. Our primary aim is to investigate genome-wide methylation in conferring risk for current suicidal ideation (SI) in schizophrenia. The presence of current SI and genome-wide methylation patterns were assessed in 107 patients with schizophrenia. DNA methylation has been measured in white blood cells as a possible peripheral biomarker of SI. SI was the primary outcome variable in a model including methylation status of white blood cells using the Illumina 450 array. We have tested the association with genome-wide methylation levels in 19 subjects with current SI and 88 subjects without current SI and we found that higher methylation level in the CpG cg06121808 located in the gene SLC20A1 on chromosome 2 was associated with current SI (p = 0.000003; beta difference = 0.06). Furthermore, the distal promoter analysis showed that the gene SMPD2 was hypermethylated in suicide ideators (p = 0.0001; beta difference = 0.02). Thus, molecular biomarkers could advance our understanding of the molecular mechanisms of stress-related SI. Furthermore, the methylation sites that we have identified should be replicated in other suicide related phenotypes to generate robust biomarkers with high translational value for proof of concept interventions aiming at reducing SI.


Assuntos
Esquizofrenia , Proteínas Cotransportadoras de Sódio-Fosfato Tipo III/genética , Esfingomielina Fosfodiesterase/genética , Ideação Suicida , Metilação de DNA , Estudo de Associação Genômica Ampla , Humanos , Regiões Promotoras Genéticas , Esquizofrenia/genética
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