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1.
J Alzheimers Dis Rep ; 7(1): 1179-1186, 2023.
Article in English | MEDLINE | ID: mdl-38025796

ABSTRACT

Background: The "Triana Test" is a novel story recall test based on emotional material with demonstrated accuracy in diagnosing mild cognitive impairment patients. Objective: This study aims to obtain normative data for the "Triana Test". Methods: A normative study was conducted at a university hospital in Spain. Partners of patients were systematically recruited if eligible (age ≥50, no memory complaints, and a total TMA-93 score at or above the 10th percentile). The "Triana Test" was administered and scored. For developing the normative data, a regression-based method was followed. Results: The final sample included 362 participants (median age = 66, range = 50-88; 64.9% females). A model including age and educational level better predicted the total scores. Combinations of these variables resulted in different 10th percentile scores. Conclusions: Norms for using the "Triana Test" are now available. The provided cutoffs for the 10th percentile will aid in the diagnosis of prodromal Alzheimer's disease.

2.
J Alzheimers Dis ; 95(1): 119-129, 2023.
Article in English | MEDLINE | ID: mdl-37482991

ABSTRACT

BACKGROUND: TMA-93 examines relational binding using images. Biomarker validation has demonstrated that it is discriminative for diagnosing early AD. The effect of cognitive reserve on TMA-93 performance remains unexplored and could improve the interpretative framework for using the test. OBJECTIVE: To study the effect of cognitive reserve on TMA-93 performance and to provide new norms for the test that include its measurement. METHODS: Cognitively unimpaired people aged 55 and over were systematically recruited for this cross-sectional normative study in southern Spain. Age, sex, and scores on the Cognitive Reserve Questionnaire (CRQ; maximum score: 25 points) were collected, and the TMA-93 was administered (maximum score: 30 points). Percentile-based reference data that captured combinations of socio-demographics variables with significant effect on TMA-93 performance were calculated. RESULTS: 902 participants (62.5% female; age: median = 68, IQR = 61-75, range = 55-90) were included. CRQ total scores were globally low (median = 8, IQR = 5-13, range = 0-24). Cognitive reserve, including modifiable items as reading activity and intellectual gaming activity, and age mainly supported the TMA-93 total score variance. Sex seemed to have some influence in the elderly. TMA-93 total scores medians began to drop from 70-75 years old. Higher total score on the CRQ and, possibly, female sex determined a gentler slope. New norms based on these variables showed wide variations in scores for the 5th and 10th percentiles. CONCLUSION: Visual relational binding ability depends on cognitive reserve, including modifiable items. The age-related binding deficit is buffered by higher cognitive reserve and, at older ages, by female sex.


Subject(s)
Cognitive Dysfunction , Cognitive Reserve , Aged , Humans , Female , Male , Neuropsychological Tests , Cross-Sectional Studies , Reading , Surveys and Questionnaires , Cognitive Dysfunction/diagnosis
3.
Int J Mol Sci ; 23(13)2022 Jul 04.
Article in English | MEDLINE | ID: mdl-35806435

ABSTRACT

Long-chain polyunsaturated fatty acids (LCPUFA), essential molecules whose precursors must be dietary supplied, are highly represented in the brain contributing to numerous neuronal processes. Recent findings have demonstrated that LCPUFA are represented in lipid raft microstructures, where they favor molecular interactions of signaling complexes underlying neuronal functionality. During aging, the brain lipid composition changes affecting the lipid rafts' integrity and protein signaling, which may induce memory detriment. We investigated the effect of a n-3 LCPUFA-enriched diet on the cognitive function of 6- and 15-months-old female mice. Likewise, we explored the impact of dietary n-3 LCPUFAs on hippocampal lipid rafts, and their potential correlation with aging-induced neuroinflammation. Our results demonstrate that n-3 LCPUFA supplementation improves spatial and recognition memory and restores the expression of glutamate and estrogen receptors in the hippocampal lipid rafts of aged mice to similar profiles than young ones. Additionally, the n-3 LCPUFA-enriched diet stabilized the lipid composition of the old mice's hippocampal lipid rafts to the levels of young ones and reduced the aged-induced neuroinflammatory markers. Hence, we propose that n-3 LCPUFA supplementation leads to beneficial cognitive performance by "rejuvenating" the lipid raft microenvironment that stabilizes the integrity and interactions of memory protein players embedded in these microdomains.


Subject(s)
Fatty Acids, Omega-3 , Fatty Acids, Unsaturated , Aging/metabolism , Animals , Dietary Supplements , Fatty Acids/metabolism , Fatty Acids, Omega-3/metabolism , Fatty Acids, Omega-3/pharmacology , Fatty Acids, Unsaturated/metabolism , Female , Hippocampus/metabolism , Membrane Microdomains/metabolism , Mice , Neuroinflammatory Diseases
4.
J Alzheimers Dis ; 88(2): 503-512, 2022.
Article in English | MEDLINE | ID: mdl-35599485

ABSTRACT

BACKGROUND: TMA-93 examines relational binding using images. The test has been proven to be discriminative for diagnosing early Alzheimer's disease by biomarkers. Norms for this test are available, but the elderly, at high risk for Alzheimer's disease, have not yet been widely represented. OBJECTIVE: To extend normative data on the TMA-93 for people aged 75 and over. METHODS: An extension of the Spanish TMA-93 normative study was undertaken. Only cognitively unimpaired people aged 75 and over were included. Age, gender, and educational attainment were registered as socio-demographic variables. Using histograms analysis, median comparisons, and linear regression analysis, we selected variables that demonstrated influence on TMA-93 total scores and provided percentile-base reference data according to combinations of those variables. RESULTS: We included 431 new participants, resulting in a total sample of 657 individuals (median age = 78, interquartile range = 76-81, range = 75-93). Percentile-base reference data stratified by a combination of age ranges (75-79, n = 428; and ≥80 years, n = 229), and educational attainment (< first grade, n = 253; first grade, n = 209; > first grade, n = 195) revealed that participants achieved a minimum TMA-93 total score of 26/30 at the 50th-percentile regardless of stratum. At the 10th-percentile, a maximum of 24/30 was achieved in the more educated stratum contrasting with a minimum of 19/30 in the less educated stratum. CONCLUSION: Although mitigated by lower levels of education, performance on the TMA-93 is widely preserved in cognitively unimpaired people aged 75 and over. The test could facilitate the screening of elderly patients with memory complaints.


Subject(s)
Alzheimer Disease , Aged , Alzheimer Disease/diagnostic imaging , Educational Status , Humans , Linear Models , Mass Screening , Neuropsychological Tests , Reference Values
5.
Front Mol Neurosci ; 15: 879146, 2022.
Article in English | MEDLINE | ID: mdl-35600079

ABSTRACT

There exists considerable interest to unveil preclinical period and prodromal stages of Alzheimer's disease (AD). The mild cognitive impairment (MCI) is characterized by significant memory and/or other cognitive domains impairments, and is often considered the prodromal phase of AD. The cerebrospinal fluid (CSF) levels of ß-amyloid (ßA), total tau (t-tau), and phosphorylated tau (p-tau) have been used as biomarkers of AD albeit their significance as indicators during early stages of AD remains far from accurate. The new biomarkers are being intensively sought as to allow identification of pathological processes underlying early stages of AD. Fifty-three participants (75.4 ± 8.3 years) were classified in three groups as cognitively normal healthy controls (HC), MCI, and subjective memory complaints (SMC). The subjects were subjected to a battery of neurocognitive tests and underwent lumbar puncture for CSF extraction. The CSF levels of estrogen-receptor (ER)-signalosome proteins, ßA, t-tau and p-tau, were submitted to univariate, bivariate, and multivariate statistical analyses. We have found that the components of the ER-signalosome, namely, caveolin-1, flotilin-1, and estrogen receptor alpha (ERα), insulin growth factor-1 receptor ß (IGF1Rß), prion protein (PrP), and plasmalemmal voltage dependent anion channel 1 (VDAC) could be detected in the CSF from all subjects of the HC, MCI, and SMC groups. The six proteins appeared elevated in MCI and slightly increased in SMC subjects compared to HC, suggesting that signalosome proteins undergo very early modifications in nerve cells. Using a multivariate approach, we have found that the combination of ERα, IGF-1Rß, and VDAC are the main determinants of group segregation with resolution enough to predict the MCI stage. The analyses of bivariate relationships indicated that collinearity of ER-signalosome proteins vary depending on the stage, with some pairs displaying opposed relationships between HC and MCI groups, and the SMC stage showing either no relationships or behaviors similar to either HC or MCI stages. The multinomial logistic regression models of changes in ER-signalosome proteins provide reliable predictive criteria, particularly for the MCI. Notably, most of the statistical analyses revealed no significant relationships or interactions with classical AD biomarkers at either disease stage. Finally, the multivariate functions were highly correlated with outcomes from neurocognitive tests for episodic memory. These results demonstrate that alterations in ER-signalosome might provide useful diagnostic information on preclinical stages of AD, independently from classical biomarkers.

6.
J Alzheimers Dis ; 86(1): 387-402, 2022.
Article in English | MEDLINE | ID: mdl-35068467

ABSTRACT

BACKGROUND: There exists considerable interest in the identification of molecular traits during early stages of Alzheimer's disease (AD). Mild cognitive impairment (MCI) is considered the closest prodromal stage of AD, and to develop gradually from earlier stages although not always progresses to AD. Classical cerebrospinal fluid (CSF) AD biomarkers, amyloid-ß peptides and tau/p-tau proteins, have been measured in prodromal stages yet results are heterogeneous and far from conclusive. Therefore, there exists a pressing need to identify a neurochemical signature for prodromal stages and to predict which cases might progress to AD. OBJECTIVE: Exploring potential CSF biomarkers related to brain oxidative and inorganic biochemistry during prodromal stages of the disease. METHODS: We have analyzed CSF levels of lipoxidative markers (MDA and 8-isoF2α), biometals (Cu, Zn, Se, Mn, and Fe), iron-transport protein transferrin (TFER), antioxidant enzymes (SOD and GPx4), detoxifying enzymes (GST and BuChE), as well as classical amyloid-ß and total and phosphorylated tau, in cognitively healthy controls, patients with MCI, and subjects exhibiting subjective memory complaints (SMC). RESULTS: Inter-group differences for several variables exhibit differentiable trends along the HC ⟶ SMC ⟶ MCI sequence. More interestingly, the combination of Se, Cu, Zn, SOD, TFER, and GST variables allow differentiable fingerprints for control subjects and each prodromal stage. Further, multivariate scores correlate positively with neurocognitive In-Out test, hence with both episodic memory decline and prediction to dementia. CONCLUSION: We conclude that changes in the CSF biochemistry related to brain oxidative defense and neurometallomics might provide more powerful and accurate diagnostic tools in preclinical stages of AD.


Subject(s)
Alzheimer Disease , Cognitive Dysfunction , Trace Elements , Alzheimer Disease/cerebrospinal fluid , Alzheimer Disease/diagnosis , Amyloid beta-Peptides/cerebrospinal fluid , Antioxidants , Biomarkers/cerebrospinal fluid , Cognitive Dysfunction/cerebrospinal fluid , Cognitive Dysfunction/diagnosis , Disease Progression , Humans , Peptide Fragments/cerebrospinal fluid , Prodromal Symptoms , Superoxide Dismutase , tau Proteins/cerebrospinal fluid
7.
Antioxidants (Basel) ; 10(6)2021 Jun 03.
Article in English | MEDLINE | ID: mdl-34205196

ABSTRACT

DHA (docosahexaenoic acid) is perhaps the most pleiotropic molecule in nerve cell biology. This long-chain highly unsaturated fatty acid has evolved to accomplish essential functions ranging from structural components allowing fast events in nerve cell membrane physiology to regulation of neurogenesis and synaptic function. Strikingly, the plethora of DHA effects has to take place within the hostile pro-oxidant environment of the brain parenchyma, which might suggest a molecular suicide. In order to circumvent this paradox, different molecular strategies have evolved during the evolution of brain cells to preserve DHA and to minimize the deleterious effects of its oxidation. In this context, DHA has emerged as a member of the "indirect antioxidants" family, the redox effects of which are not due to direct redox interactions with reactive species, but to modulation of gene expression within thioredoxin and glutathione antioxidant systems and related pathways. Weakening or deregulation of these self-protecting defenses orchestrated by DHA is associated with normal aging but also, more worryingly, with the development of neurodegenerative diseases. In the present review, we elaborate on the essential functions of DHA in the brain, including its role as indirect antioxidant, the selenium connection for proper antioxidant function and their changes during normal aging and in Alzheimer's disease.

8.
Nursing ; 51(7): 47-50, 2021 Jul 01.
Article in English | MEDLINE | ID: mdl-34157002

ABSTRACT

ABSTRACT: Accurate and precise BP measurements are crucial to clinical decision-making and interventions as healthcare professionals aim to prevent complications from hypertension, yet the literature provides no gold standard for measuring BP. This article discusses the additional research necessary to develop best practices and improve patient outcomes.


Subject(s)
Blood Pressure Determination/nursing , Blood Pressure Determination/standards , Humans , Reproducibility of Results
9.
Int J Mol Sci ; 22(10)2021 May 19.
Article in English | MEDLINE | ID: mdl-34069498

ABSTRACT

Tamoxifen is the most widely used selective modulator of estrogen receptors (SERM) and the first strategy as coadjuvant therapy for the treatment of estrogen-receptor (ER) positive breast cancer worldwide. In spite of such success, tamoxifen is not devoid of undesirable effects, the most life-threatening reported so far affecting uterine tissues. Indeed, tamoxifen treatment is discouraged in women under risk of uterine cancers. Recent molecular design efforts have endeavoured the development of tamoxifen derivatives with antiestrogen properties but lacking agonistic uterine tropism. One of this is FLTX2, formed by the covalent binding of tamoxifen as ER binding core, 7-nitrobenzofurazan (NBD) as the florescent dye, and Rose Bengal (RB) as source for reactive oxygen species. Our analyses demonstrate (1) FLTX2 is endowed with similar antiestrogen potency as tamoxifen and its predecessor FLTX1, (2) shows a strong absorption in the blue spectral range, associated to the NBD moiety, which efficiently transfers the excitation energy to RB through intramolecular FRET mechanism, (3) generates superoxide anions in a concentration- and irradiation time-dependent process, and (4) Induces concentration- and time-dependent MCF7 apoptotic cell death. These properties make FLTX2 a very promising candidate to lead a novel generation of SERMs with the endogenous capacity to promote breast tumour cell death in situ by photosensitization.


Subject(s)
Estrogen Antagonists/chemistry , Tamoxifen/analogs & derivatives , Tamoxifen/pharmacology , Breast Neoplasms/metabolism , Estrogen Receptor Modulators/pharmacology , Estrogens/metabolism , Female , Fluorescent Dyes/chemistry , Fluorescent Dyes/pharmacology , Humans , Molecular Dynamics Simulation , Photosensitizing Agents/chemistry , Photosensitizing Agents/pharmacology , Receptors, Estrogen/metabolism , Selective Estrogen Receptor Modulators/chemistry , Selective Estrogen Receptor Modulators/pharmacology , Uterus/metabolism
10.
Int J Mol Sci ; 20(15)2019 Aug 04.
Article in English | MEDLINE | ID: mdl-31382686

ABSTRACT

Lipids in the brain are major components playing structural functions as well as physiological roles in nerve cells, such as neural communication, neurogenesis, synaptic transmission, signal transduction, membrane compartmentalization, and regulation of gene expression. Determination of brain lipid composition may provide not only essential information about normal brain functioning, but also about changes with aging and diseases. Indeed, deregulations of specific lipid classes and lipid homeostasis have been demonstrated in neurodegenerative disorders such as Alzheimer's disease (AD) and Parkinson's disease (PD). Furthermore, recent studies have shown that membrane microdomains, named lipid rafts, may change their composition in correlation with neuronal impairment. Lipid rafts are key factors for signaling processes for cellular responses. Lipid alteration in these signaling platforms may correlate with abnormal protein distribution and aggregation, toxic cell signaling, and other neuropathological events related with these diseases. This review highlights the manner lipid changes in lipid rafts may participate in the modulation of neuropathological events related to AD and PD. Understanding and characterizing these changes may contribute to the development of novel and specific diagnostic and prognostic biomarkers in routinely clinical practice.


Subject(s)
Aging/metabolism , Lipids/genetics , Membrane Microdomains/metabolism , Neurodegenerative Diseases/metabolism , Aging/genetics , Aging/pathology , Alzheimer Disease/genetics , Alzheimer Disease/metabolism , Alzheimer Disease/pathology , Biomarkers/metabolism , Brain/metabolism , Brain/pathology , Humans , Membrane Microdomains/pathology , Neurodegenerative Diseases/genetics , Neurodegenerative Diseases/pathology , Neurons/metabolism , Neurons/pathology , Parkinson Disease/genetics , Parkinson Disease/metabolism , Parkinson Disease/pathology , Signal Transduction/genetics
11.
J Alzheimers Dis ; 67(1): 265-277, 2019.
Article in English | MEDLINE | ID: mdl-30530971

ABSTRACT

BACKGROUND: Assessment of hippocampal amnesia is helpful to distinguish between normal cognition and mild cognitive impairment (MCI), but not for identifying converters to dementia. Here biomarkers are useful but novel neuropsychological approaches are needed in their absence. The In-out-test assesses episodic memory using a new paradigm hypothesized to avoid reliance on executive function, which may compensate for damaged memory networks. OBJECTIVE: To assess the validity of the In-out-test in identifying prodromal Alzheimer's disease (PAD) in a clinical setting, by comparing this to the Free and Cued Selective Reminding Test (FCSRT) and cerebrospinal fluid biomarkers. METHODS: A cross-sectional study of 32 cognitively healthy, 32 MCI, and 30 progressive dementia subjects. All participants were given both the In-out-test and the FCSRT; 40 of them also received a lumbar puncture. RESULTS: Internal consistency was demonstrated using Cronbach Alpha (r = 0.81) and Inter-rater reliability with Kappa (k = 0.94). Intraclass correlation (ICC) for test-retest reliability: r = 0.57 (p = 0.57). ICC between the In-out-test and FCSRT r = 0.87 (p = 0.001). ICC between the In-out-test and Aß42 and P-tau/Aß42 for controls: 0.73 and 0.75, respectively; P-tau for MCI: 0.77 and total sample: 0.70; Aß42 for dementia: 0.71. All ICC measures between FCSRT and biomarkers were ≤0.264. AD diagnosis: In-out-test k = 0.71; FCSRT k = 0.49. PAD diagnosis (N = 35): In-out-test k = 0.69; FCSRT k = 0.44. CONCLUSIONS: The In-out-test detected prodromal AD with a higher degree of accuracy than a conventional hippocampal-based memory test. These results suggest that this new paradigm could be of value in clinical settings, predicting which patients with MCI will go on to develop AD.


Subject(s)
Alzheimer Disease/diagnosis , Neuropsychological Tests , Aged , Aged, 80 and over , Alzheimer Disease/cerebrospinal fluid , Amyloid beta-Peptides/cerebrospinal fluid , Biomarkers/cerebrospinal fluid , Cognitive Dysfunction/cerebrospinal fluid , Cognitive Dysfunction/diagnosis , Cross-Sectional Studies , Cues , Female , Humans , Male , Memory Disorders/diagnosis , Memory, Episodic , Middle Aged , Peptide Fragments/cerebrospinal fluid , Reproducibility of Results , tau Proteins/cerebrospinal fluid
12.
Suma psicol ; 25(2): 146-152, jul.-dic. 2018. tab
Article in Spanish | LILACS-Express | LILACS | ID: biblio-1004730

ABSTRACT

Resumen En este estudio se tuvo como objetivo analizar la relación entre la autoestima sexual (AS) y la excitación sexual como rasgo, estado y componente de la respuesta sexual. La muestra estuvo compuesta por 65 jóvenes heterosexuales que completaron la subescala Excitación Sexual de las Sexual Inhibition/Sexual Excitation Scales-Short Form, el Massachussets General Hospital Sexual Functioning Questionnaire y la subescala Autoestima sexual del Brief Sexuality Scale. A continuación, realizaron una tarea experimental donde completaron las escalas Valoración de Excitación Sexual y Valoración de Sensaciones Genitales tras visualizar un video neutro y otro con contenido sexual explícito. Los resultados mostraron asociaciones significativas entre la AS y la excitación sexual rasgo y la excitación sexual como componente de la respuesta sexual. Ambas manifestaciones de la excitación sexual explicaron un porcentaje significativo de la AS (R 2 = 0,19). Sin embargo, la excitación sexual estado no se asoció con la AS.


Abstract The aim was to analyze the relationship between sexual self-esteem (SSE) and sexual arousal as a trait, as a state and as a component of the sexual response. The sample consisted of 65 heterosexual young people who completed the Sexual Excitation subscale of the Sexual Inhibition/Sexual Excitation Scales-Short Form, the Massachusetts General Hospital Sexual Functioning Questionnaire, and the Sexual Self-esteem subscale of the Brief Sexuality Scale. Participants performed an experimental task where they completed the Ratings of Sexual Arousal and the Ratings of Genital Sensations after visualizing a neutral film and another one with explicit sexual content. The results showed significant associations between SSE and sexual arousal as a trait and as a component of the sexual response. These two types of excitation explained a significant percentage of the SSE (R 2 = 0.19). However, sexual arousal as a state did not correlate to the SSE.

13.
Front Biosci (Schol Ed) ; 9(1): 111-126, 2017 01 01.
Article in English | MEDLINE | ID: mdl-27814578

ABSTRACT

The increase in the incidence of Alzheimer's disease (AD) in old women may be attributable to estrogen deficiency, and estrogen replacement therapy may be useful in preventing or delaying the onset of this disease. In neuronal membranes, 17 beta-estradiol interacts with estrogen receptors (mERs) located in lipid raft signalosomes which trigger neuroprotective responses by anchoring to scaffolding caveolin-1 complexed with other proteins. We suggest that mER-signalosome malfunctions in AD and by menopause due to development of aberrations in these microstructures. Here, we report that mER dissociates from a voltage-dependent anion channel (VDAC), and that progressive dephosphorylation of VDAC1 enhances neurotoxicity. mER dissociates from caveolin-1 and other neuroprotective proteins, including insulin-like growth factor 1 receptor beta. Similar signalosome disarrangements are observed in AD patients. Moreover, in AD, lipid rafts exhibit alterations in lipid composition, and these changes cause an increase in liquid-ordered as compared to controls. Together, the data show that AD and menopause lead to disruption in the lipid raft structure, and disfunctioning of ER alpha and other neuroprotectors integrated into these signalosomes.


Subject(s)
Alzheimer Disease/metabolism , Estrogen Receptor alpha/metabolism , Membrane Microdomains/metabolism , Menopause/metabolism , Aged , Caveolin 1 , Female , Frontal Lobe/metabolism , Humans , Middle Aged , Phosphorylation , Voltage-Dependent Anion Channel 1/metabolism
14.
Curr Alzheimer Res ; 13(9): 973-84, 2016.
Article in English | MEDLINE | ID: mdl-26971937

ABSTRACT

Lipid rafts are membrane microdomains particularly enriched in cholesterol, sphingolipids and saturated fatty acids. These microstructures play a key role in a plethora of mechanisms involved in cell signaling, synapsis, cell-cell communication and cell survival. In the last years, increasing evidence indicate that lipid rafts may be altered in age-related neuropathologies, such as Alzheimer's disease and Parkinson disease even at asymptomatic stages. In particular, important changes in raft lipid composition are observed with the progression of these diseases, then inducing alterations in their physicochemical properties. Furthermore, these phenomena contribute to neuropathological events related to amyloidogenesis, aberrant protein aggregation and toxic cell signalling. In this review, we discuss some relevant data on the age-related molecular changes occurring in lipid rafts since the first stages of these neurodegenerative diseases. Further characterization of specific parameters associated with alterations of these microdomains may provide potential tools of diagnosis and prediction of these neuropathologies.


Subject(s)
Aging/metabolism , Membrane Microdomains/metabolism , Neurodegenerative Diseases/metabolism , Aging/pathology , Animals , Disease Progression , Humans , Membrane Microdomains/pathology , Neurodegenerative Diseases/diagnosis , Neurodegenerative Diseases/pathology
15.
J Biol Chem ; 286(9): 7149-60, 2011 Mar 04.
Article in English | MEDLINE | ID: mdl-21183686

ABSTRACT

Poly(ADP-ribose) polymerase-1 (PARP-1) modifies various proteins, including itself, with ADP-ribose polymers (automodification). Polymer synthesis is triggered by binding of its zinc finger 1 (Zn1) and 2 (Zn2) to DNA breaks and is followed by inactivation through automodification. The multiple functional domains of PARP-1 appear to regulate activation and automodification-mediated inactivation of PARP-1. However, the roles of these domains in activation-inactivation processes are not well understood. Our results suggest that Zn1, Zn2, and a domain identified in this study, the double-stranded DNA binding (DsDB) domain, are involved in DNA break-dependent activation of PARP-1. We found that binding of the DsDB domain to double-stranded DNA and DNA break recognition by Zn1 and Zn2, whose actual binding targets are likely to be single-stranded DNA, lead to the activation of PARP-1. In turn, the displacement of single- and double-stranded DNA from Zn2 and the DsDB domain caused by ADP-ribose polymer synthesis results in the dissociation of PARP-1 from DNA breaks and thus its inactivation. We also found that the WGR domain is one of the domains involved in the RNA-dependent activation of PARP-1. Furthermore, because zinc finger 3 (Zn3) has the ability to bind to single-stranded RNA, it may have an indirect role in RNA-dependent activation. PARP-1 functional domains, which are involved in oligonucleic acid binding, therefore coordinately regulate PARP-1 activity depending on the status of the neighboring oligonucleic acids. Based on these results, we proposed a model for the regulation of PARP-1 activity.


Subject(s)
DNA Damage/physiology , DNA, Single-Stranded/metabolism , DNA/metabolism , Models, Chemical , Poly(ADP-ribose) Polymerases , Adenosine Diphosphate Ribose/metabolism , Binding Sites/physiology , DNA Breaks, Double-Stranded , Humans , Peptide Fragments/chemistry , Peptide Fragments/genetics , Peptide Fragments/metabolism , Poly (ADP-Ribose) Polymerase-1 , Poly(ADP-ribose) Polymerases/chemistry , Poly(ADP-ribose) Polymerases/genetics , Poly(ADP-ribose) Polymerases/metabolism , Protein Structure, Tertiary , RNA/metabolism , Structure-Activity Relationship , Zinc Fingers/physiology
16.
J Med Chem ; 45(10): 1971-82, 2002 May 09.
Article in English | MEDLINE | ID: mdl-11985465

ABSTRACT

A one-bead-two-compound inhibitor library was synthesized by the split-mix method for the identification of inhibitors of a recombinant cysteine protease from Leishmania mexicana, CPB2.8DeltaCTE. The inhibitor library was composed of octapeptides with a centrally located reduced bond introduced by reductive amination of the resin-bound amines with Fmoc amino aldehydes. The library was screened on solid phase, and less than 1% of the library contained active compounds. The inhibitors displayed great specificity in the subsites flanking the enzyme catalytic triad with Cha and Ile/Leu preferred in P(2), Phe in P(1), Cha and Ile/Leu in P(1)', and Ile/Leu in P(2)'. Some of the inhibitors were resynthesized, and the kinetics of inhibition were determined in solution-phase assays. Most of the inhibitors had micromolar K(i) values, and a few inhibited the enzyme at nanomolar concentrations. One inhibitor, DKHF(CH(2)NH)LLVK (K(i) = 1 microm), was tested for antiparasite efficacy and shown to affect parasite survival with an IC(50) of approximately 50 microm.


Subject(s)
Cysteine Proteinase Inhibitors/chemical synthesis , Leishmania mexicana/enzymology , Oligopeptides/chemical synthesis , Amination , Animals , Combinatorial Chemistry Techniques , Cysteine Proteinase Inhibitors/chemistry , Cysteine Proteinase Inhibitors/pharmacology , Drug Evaluation, Preclinical , In Vitro Techniques , Macrophages/drug effects , Macrophages/parasitology , Mice , Mice, Inbred BALB C , Models, Molecular , Oligopeptides/chemistry , Oligopeptides/pharmacology , Oxidation-Reduction , Polyethylene Glycols , Recombinant Proteins/antagonists & inhibitors , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization , Structure-Activity Relationship
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