RESUMO
DNA Ligase IV is responsible for sealing of double-strand breaks (DSBs) during nonhomologous end-joining (NHEJ). Inhibiting Ligase IV could result in amassing of DSBs, thereby serving as a strategy toward treatment of cancer. Here, we identify a molecule, SCR7 that inhibits joining of DSBs in cell-free repair system. SCR7 blocks Ligase IV-mediated joining by interfering with its DNA binding but not that of T4 DNA Ligase or Ligase I. SCR7 inhibits NHEJ in a Ligase IV-dependent manner within cells, and activates the intrinsic apoptotic pathway. More importantly, SCR7 impedes tumor progression in mouse models and when coadministered with DSB-inducing therapeutic modalities enhances their sensitivity significantly. This inhibitor to target NHEJ offers a strategy toward the treatment of cancer and improvement of existing regimens.
Assuntos
Quebras de DNA de Cadeia Dupla , Reparo do DNA por Junção de Extremidades/efeitos dos fármacos , DNA Ligases/antagonistas & inibidores , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Pirimidinas/uso terapêutico , Bases de Schiff/uso terapêutico , Sequência de Aminoácidos , Animais , Linhagem Celular Tumoral , DNA Ligase Dependente de ATP , DNA Ligases/química , DNA Ligases/genética , Modelos Animais de Doenças , Desenho de Fármacos , Resistencia a Medicamentos Antineoplásicos , Humanos , Linfócitos/efeitos dos fármacos , Linfoma/tratamento farmacológico , Linfoma/patologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Modelos Moleculares , Dados de Sequência Molecular , Estrutura Terciária de Proteína , Pirimidinas/síntese química , Pirimidinas/química , Tolerância a Radiação , Ratos , Bases de Schiff/síntese química , Bases de Schiff/química , Alinhamento de SequênciaRESUMO
Background and Objective. The role of adipokines in regulation of immune responses has been recognized, but very little is known about their impact on multiple sclerosis (MS). In this study, we analysed whether the major adipokines are differentially expressed in plasma of patients with different MS subtypes and clinically isolated syndrome (CIS) and explored their association with major disease characteristics. Methods. The levels of adiponectin, adipsin, leptin, and resistin in the plasma of 80 patients with different subtypes of MS and CIS were followed up annually over the two years. The data obtained were correlated with disease activity, EDSS and volumes of T1-weighted lesions (T1-LV), and fluid attenuation inversion recovery lesions (FLAIR-LV) on MRI. Results. In MS group, a correlation was found between the level of adipsin and EDSS score at baseline (r = 0.506, p < 0.001). In RRMS, the levels of adipsin correlated with EDSS scores (r = 0.542, p = 0.002), T1-LV (r = 0.410, p = 0.034), and FLAIR-LV (r = 0.601, p = 0.0001) at baseline and an increase in the T1-LV over the follow-up (r = 0.582, p = 0.003). Associations with other adipokines were not detected. Conclusion. Our exploratory study provides novel insights on the impact of adipokines in MS and suggests that adipsin exerts predictive potential as a biomarker of neurodegeneration.
RESUMO
The aim of this study was to evaluate diffusion tensor imaging (DTI) indices in the corpus callosum and pyramidal tract in normal-appearing white matter (NAWM) and the caudate nucleus and thalamus in deep grey matter (NADGM) in all MS subtypes and clinically isolated syndrome (CIS). Furthermore, it was determined whether these metrics are associated with clinical measures and the serum levels of candidate immune biomarkers. Apparent diffusion coefficients (ADC) values were significantly higher than in controls in all six studied NAWM regions in SPMS, 4/6 regions in RRMS and PPMS and 2/6 regions in CIS. In contrast, decreased fractional anisotropy (FA) values in comparison to controls were detected in 2/6 NAWM regions in SPMS and 1/6 in RRMS and PPMS. In RRMS, the level of neurological disability correlated with thalamic FA values (r = 0.479, P = 0.004). In chronic progressive subtypes and CIS, ADC values of NAWM and NADGM were associated with the levels of MIF, sFas, and sTNF- α . Our data indicate that DTI may be useful in detecting pathological changes in NAWM and NADGM in MS patients and that these changes are related to neurological disability.
RESUMO
Prolyl oligopeptidase (PREP) has been considered as a drug target for the treatment of neurodegenerative diseases. In plasma, PREP has been found altered in several disorders of the central nervous system including multiple sclerosis (MS). Oxidative stress and the levels of an endogenous plasma PREP inhibitor have been proposed to decrease PREP activity in MS. In this work, we measured the circulating levels of PREP in patients suffering of relapsing remitting (RR), secondary progressive (SP), primary progressive (PP) MS, and in subjects with clinically isolated syndrome (CIS). We found a significantly lower PREP activity in plasma of RRMS as well as in PPMS patients and a trend to reduced activity in subjects diagnosed with CIS, compared to controls. No signs of oxidative inactivation of PREP, and no correlation with the endogenous PREP inhibitor, identified as activated α-2-macroglobulin (α2M*), were observed in any of the patients studied. However, a significant decrease of α2M* was recorded in MS. In cell cultures, we found that PREP specifically stimulates immune active cells possibly by modifying the levels of fibrinogen ß, thymosin ß4, and collagen. Our results open new lines of research on the role of PREP and α2M* in MS, aiming to relate them to the diagnosis and prognosis of this devastating disease.
Assuntos
Doenças Desmielinizantes/sangue , Esclerose Múltipla Crônica Progressiva/sangue , Esclerose Múltipla Recidivante-Remitente/sangue , Serina Endopeptidases/sangue , alfa-Macroglobulinas/metabolismo , Adulto , Idoso , Animais , Biomarcadores/sangue , Linhagem Celular Tumoral , Doenças Desmielinizantes/diagnóstico , Feminino , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Esclerose Múltipla/sangue , Esclerose Múltipla/diagnóstico , Esclerose Múltipla Crônica Progressiva/diagnóstico , Esclerose Múltipla Recidivante-Remitente/diagnóstico , Prolil Oligopeptidases , Adulto JovemRESUMO
In this study we investigated the relationship between melatonin pathway and multiple sclerosis (MS) in a high-risk Finnish population by studying the single nucleotide polymorphisms (SNPs) in the genes coding for critical enzymes and receptors involved in the melatonin pathway. A total of 590 subjects (193 MS patients and 397 healthy controls) were genotyped for seven SNPs in four genes including tryptophan hydroxylases (TPH)1 and 2, arylalkylamine N-acetyltransferase (AANAT) and melatonin receptor 1B (MTNR1B). An overrepresentation of T allele carriers of a functional polymorphism (G-703T, rs4570625) in the promoter region of TPH2 gene was observed in the progressive MS subtypes. The haplotype rs4570625-rs10506645TT of TPH2 gene was associated with the risk of severe disability in primary progressive MS (PPMS), while haplotype rs4570625-rs10506645TC appeared to be protective against disability in secondary progressive MS (SPMS). In the MTNR1B gene, the haplotype rs10830963-rs4753426GC was associated with the risk of SPMS, whereas another haplotype rs10830963-rs4753426GT showed an association with the risk of PPMS. These data showing the association of polymorphisms in the TPH2 and MTNR1B genes with the progressive subtypes of MS and disability suggest dysregulation in melatonin pathway. Melatonin pathway seems to be involved in disease progression, and therefore its potential effects in overcoming MS-related neurodegeneration may be worth evaluating in future clinical trials.