Working memory deficits in schizophrenia are associated with the rs34884856 variant and expression levels of the NR4A2 gene in a sample Mexican population: a case control study.

BACKGROUND: Cognitive functions represent useful endophenotypes to identify the association between genetic variants and schizophrenia. In this sense, the NR4A2 gene has been implicated in schizophrenia and cognition in different animal models and clinical trials. We hypothesized that the NR4A2 gene is associated with working memory performance in schizophrenia. This study aimed to analyze two variants and the expression levels of the NR4A2 gene with susceptibility to schizophrenia, as well as to evaluate whether possession of NR4A2 variants influence the possible correlation between gene expression and working memory performance in schizophrenia. METHODS: The current study included 187 schizophrenia patients and 227 controls genotyped for two of the most studied NR4A2 genetic variants in neurological and neuropsychiatric diseases. Genotyping was performed using High Resolution Melt and sequencing techniques. In addition, mRNA expression of NR4A2 was performed in peripheral mononuclear cells of 112 patients and 118 controls. A group of these participants, 54 patients and 87 controls, performed the working memory index of the WAIS III test. RESULTS: Both genotypic frequencies of the two variants and expression levels of the NR4A2 gene showed no significant difference when in patients versus controls. However, patients homozygous for the rs34884856 promoter variant showed a positive correlation between expression levels and auditory working memory. CONCLUSIONS: Our finding suggested that changes in expression levels of the NR4A2 gene could be associated with working memory in schizophrenia depending on patients' genotype in a sample from a Mexican population.

Variability in Behavioral Phenotypes after Forced Swimming-Induced Stress in Rats Is Associated with Expression of the Glucocorticoid Receptor, Nurr1, and IL-1ß in the Hippocampus.

Individual differences in coping with stress may determine either a vulnerable or resilient phenotype. Therefore, it is important to better understand the biology underlying the behavioral phenotype. We assessed whether individual behavioral phenotype to acute stress is related with the hippocampal expression of glucocorticoid receptor (GR), Nurr1, interleukin-1 beta (IL-1ß) or brain-derived neurotrophic factor (BDNF). Wistar male rats were exposed to forced swimming for 15 min and sacrificed at different times. Behavioral response was analyzed, and it was compared with the gene and protein expression of GR, Nurr1, IL-1ß and BDNF in the hippocampus for each time point. Behavioral phenotyping showed a group with high immobility (vulnerable) while another had low immobility (resilient). No significant differences were found in the Nurr1, IL-1ß and BDNF mRNA levels between resilient and vulnerable rats at different recovery times except for Nr3c1 (gene for GR). However, exposure to stress caused significantly higher levels of GR, Nurr1 and IL-1ß proteins of vulnerable compared to resilient rats. This variability of behavioral phenotypes is associated with a differential molecular response to stress that involves GR, Nurr1, and IL-1ß as mediators in coping with stress. This contributes to identifying biomarkers of susceptibility to stress.

Active coping of prenatally stressed rats in the forced swimming test: involvement of the Nurr1 gene.

Depending on genetic predisposition, prenatal stress may result in vulnerability or resilience to develop psychiatric disorders in adulthood. Nurr1 is an immediate early gene, important in the brain for the stress response. We tested the hypothesis that prenatal stress and the decrease of hippocampal Nurr1 alter offspring behavioral responses in the forced swimming test (FST). Pregnant Wistar rats were exposed to restraint stress (45 min, thrice daily) from gestation day 14. Prenatally stressed (PS) and non-prenatally stressed (NPS) male offspring were treated bilaterally with a Nurr1 antisense oligodeoxynucleotide (ODN; or control) into the hippocampus at 97 d of age. After 1 h, the rats were exposed to the FST (acute stressor) to analyze their behavioral responses. Thirty minutes after the FST, we analyzed the gene expression of Nurr1, Bdnf and Nr3c1 (genes for Nurr1, brain-derived neurotrophic factor (BDNF) and glucocorticoid receptor (GR), respectively) in the hippocampus, prefrontal cortex (PFC) and hypothalamus. Results showed that the decrease of hippocampal Nurr1 after the antisense ODN in adult NPS rats induces immobility (indicating depressive-like behavior). The PS adult rats, including the group with decreased hippocampal Nurr1, presented low immobility in the FST. This low immobility was concordant with maintenance of Nurr1 and Bdnf expression levels in the three analyzed brain regions; Nr3c1 gene expression was also maintained in the PFC and hypothalamus. These findings suggest that Nurr1 and associated genes could participate in the brain modifications induced by prenatal stress, allowing active coping (resilience) with acute stress in adulthood.

Human Health Risk Assessment of Arsenic and Other Metals in Herbal Products Containing St. John's Wort in the Metropolitan Area of Mexico City.

Consumption of St. John's wort plant is high worldwide due to its various medicinal properties. However, herbal products containing St. John's wort may be contaminated with toxic metals. This is often related to contamination of both water and the atmosphere, lack of proper cultivation methods, and inadequate plant storage conditions, as well as a lack of stricter sanitary supervision. A safety assessment of copper (Cu), lead (Pb), cadmium (Cd) and arsenic (As) content in 23 products containing St. John's wort (pharmaceutical herbal products, food supplements and traditional herbal remedies) sold in the metropolitan area of Mexico City was conducted. The analysis of metals was determined using a graphite-furnace atomic absorption spectrometer. All herbal products were contaminated with Cu, Pb, Cd and As. The pharmaceutical herbal items showed less contamination by metals. The daily human intake (DHI) values for Pb exceeded the permissible limits in the group of traditional herbal remedies. The DHI calculation for As exceeded the permitted intake values for all items in the group of traditional herbal remedies, five food supplements and one pharmaceutical herbal product. The hazard indicator calculation of the non-carcinogenic cumulative risk values for traditional herbal remedies was greater than 1, suggesting a risk to human health.

Neuroprotective-Neurorestorative Effects Induced by Progesterone on Global Cerebral Ischemia: A Narrative Review.

Progesterone (P4) is a neuroactive hormone having pleiotropic effects, supporting its pharmacological potential to treat global (cardiac-arrest-related) cerebral ischemia, a condition associated with an elevated risk of dementia. This review examines the current biochemical, morphological, and functional evidence showing the neuroprotective/neurorestorative effects of P4 against global cerebral ischemia (GCI). Experimental findings show that P4 may counteract pathophysiological mechanisms and/or regulate endogenous mechanisms of plasticity induced by GCI. According to this, P4 treatment consistently improves the performance of cognitive functions, such as learning and memory, impaired by GCI. This functional recovery is related to the significant morphological preservation of brain structures vulnerable to ischemia when the hormone is administered before and/or after a moderate ischemic episode; and with long-term adaptive plastic restoration processes of altered brain morphology when treatment is given after an episode of severe ischemia. The insights presented here may be a guide for future basic research, including the study of P4 administration schemes that focus on promoting its post-ischemia neurorestorative effect. Furthermore, considering that functional recovery is a desired endpoint of pharmacological strategies in the clinic, they could support the study of P4 treatment for decreasing dementia in patients who have suffered an episode of GCI.

Historical Aspects of Herbal Use and Comparison of Current Regulations of Herbal Products between Mexico, Canada and the United States of America.

Increased life expectancy and high costs of medicines and medical care have led to the use of herbal products. However, these items may contain toxic compounds that have an impact on public health. We will focus on the regulatory aspects and differences of these products marketed in the North American region (USA-Mexico-Canada) from government websites and selected literature. Mexico has an ancestral tradition of using plants for the treatment, improvement, and maintenance of human health as compared with Canada and the USA Currently, the use of herbal products in this region has a regulatory framework. The legal framework in these three countries is related to their history, idiosyncrasies, socio-economic and cultural aspects. Therefore, there are different public policies for herbal products consumed in the region. Mexico has a more specific classification of these products. In Canada, all herbal products are classified as natural health products and the safety and efficacy must be scientifically proven. In the USA, the development of botanical drugs is very recent. In particular, both herbal products classified as food supplements in Mexico and dietary supplements in the USA may have risks in both safety and efficacy.

Naturalistic Study of Depression Associated with Parkinson's Disease in a National Public Neurological Referral Center in Mexico.

Major depressive disorder (MDD) is a major health problem in Parkinson's disease (PD) patients. We described the clinical and sociodemographic factors of MDD among patients with PD at a national neurological referral center in Mexico. One hundred patients with PD + MDD were included in the study. All the patients were evaluated during the "ON" treatment phase of PD. Clinical scales for cognition (MMSE and MoCA) and MDD (MADRS) were applied. The mean age was 58.49 ± 11.02 years, and 57% of the sample was male. The most frequent symptom of PD was tremor (67%), and onset was more frequent on the right side (57%). Additionally, 49% of the patients with PD had moderate to severe (M/S) MDD. Selective serotonin reuptake inhibitors were the most frequent antidepressant treatment (69%). The scores of the scales were MADRS 21.33 ± 5.49, MoCA 21.06 ± 4.65, and MMSE 26.67 ± 1.20. The females had lower MMSE scores compared to the males (p = 0.043). The patients with M/S MDD had more rigidity at the beginning of PD (p = 0.005), fewer march alterations (p = 0.023), and a greater prevalence of left-side initial disease (p = 0.037). Rigidity was associated with M/S MDD (OR 3.75 p = 0.013). MDD was slightly more frequent in the males than in the females. The MDD symptoms and cognitive impairment were worse in the female population.

SORL1 Polymorphisms in Mexican Patients with Alzheimer's Disease.

The present study evaluated the risk effect of 12 Single Nucleotide Polymorphisms in the SORL1 gene in the Mexican population using Late-Onset Alzheimer's Disease (LOAD) and control subjects. Considering APOE as the strongest genetic risk factor for LOAD, we conducted interaction analyses between single nucleotide polymorphisms (SNPs) and the APOE genotype. METHODS: Patients were interviewed during their scheduled visits at neurologic and geriatric clinics from different institutions. The LOAD diagnosis included neurological, geriatric, and psychiatric examinations, as well as the medical history and neuroimaging. Polymorphisms in SORL1 were genotyped by real-time PCR in 156 subjects with LOAD and 221 controls. APOE genotype was determined in each study subject. Allelic, genotypic, and haplotypic frequencies were analyzed; an ancestry analysis was also performed. RESULTS: The A/A genotype in rs1784933 might be associated with an increased LOAD risk. Two blocks with high degree linkage disequilibrium (LD) were identified. The first block composed by the genetic variants rs668387, rs689021 and rs641120 showed a positive interaction (mainly the rs689021) with rs1784933 polymorphism. Moreover, we found a significant association between the APOE ε4 allele carriers and the variant rs2070045 located in the second LD block. CONCLUSION: The rs1784933 polymorphism is associated with LOAD in Mexican patients. In addition, the presence of APOE ε4 allele and SORL1 variants could represent a genetic interaction effect that favors LOAD risk in the Mexican population. SNPs have been proposed as genetic markers associated with the development of LOAD that can support the clinical diagnosis. Future molecular studies could help understand sporadic Alzheimer's Disease (AD) among the Mexican population, where currently there is a sub-estimate number in terms of disease frequency and incidence.

In vitro effects of stromal cells expressing different levels of Jagged-1 and Delta-1 on the growth of primitive and intermediate CD34(+) cell subsets from human cord blood.

In trying to contribute to our knowledge on the role of Notch and its ligands within the human hematopoietic system, we have assessed the effects of the OP9 stroma cell line - naturally expressing Jagged-1 - transduced with either the Delta-1 gene (OP9-DL1 cells) or with vector alone (OP9-V), on the in vitro growth of two different hematopoietic cell populations. Primitive (CD34(+) CD38(-) Lin(-)) and intermediate (CD34(+) CD38(+) Lin(-)) CD34(+) cell subsets from human cord blood were cultured in the presence of 7 stimulatory cytokines under four different conditions: cytokines alone (control); cytokines and mesenchymal stromal cells; cytokines and OP9-V cells; cytokines and OP9-DL1 cells. Proliferation and expansion were determined after 7days of culture. Culture of CD34(+) CD38(-) Lin(-) cells in the presence of OP9-V or OP9-DL1 cells resulted in a significant increase in the production of new CD34(+) CD38(-) Lin(-) cells (expansion), which expressed increased levels of Notch-1; in contrast, production of total nucleated cells (proliferation) was reduced, as compared to control conditions. In cultures of CD34(+) CD38(+) Lin(-) cells established in the presence of OP9-V or OP9-DL1 cells, expansion was similar to that observed in control conditions, whereas proliferation was also reduced. Interestingly, in these latter cultures we observed production of CD34(+) CD38(-) Lin(-) cells. Our results indicate that, as compared to MSC, OP9 cells were more efficient at inducing self-renewal and/or de novo generation of primitive (CD34(+) CD38(-) Lin(-)) cells, and suggest that such effects were due, at least in part, to the presence of Jagged-1 and DL1.

A Health Risk Assessment of Lead and Other Metals in Pharmaceutical Herbal Products and Dietary Supplements Containing Ginkgo biloba in the Mexico City Metropolitan Area.

The use of the medicinal plant Ginkgo biloba has increased worldwide. However, G. biloba is capable of assimilating both essential and toxic metals, and the ingestion of contaminated products can cause damage to health. The aim of this study was to investigate the safety of manganese (Mn), copper (Cu), lead (Pb), arsenic (As), and cadmium (Cd) in 26 items containing Ginkgo biloba (pharmaceutical herbal products, dietary supplements, and traditional herbal remedies) purchased in the metropolitan area of Mexico City. Metal analysis was performed using a graphite furnace atomic absorption spectrometer. All of the products were contaminated with Pb, 54% of them with As, and 81% with Cd. The lowest values of Pb, As, and Cd were detected in pharmaceutical herbal products > dietary supplements > traditional herbal remedies. The daily intake dose (DID) of pharmaceutical herbal products was within the established limits for the five metals. Dietary supplements and traditional herbal remedies exceeded the DID limits for Pb. The hazard quotients estimation and non-carcinogenic cumulative hazard estimation index for Mn, As, and Cd indicated no human health risk. Our results suggest that products containing G. biloba for sale in Mexico are not a health risk.

Plasma Levels of Amyloid-ß Peptides and Tau Protein in Mexican Patients with Alzheimer's Disease.

BACKGROUND: Alzheimer's disease (AD) causes memory deficit and alterations in other cognitive functions, mainly in adults over 60 years of age. As the diagnosis confirmation is performed by a postmortem neuropathological examination of the brain, this disease can be confused with other types of dementia at early stages. About 860,000 Mexicans are affected by dementia, most of them with insufficient access to adequate comprehensive health care services. Plasma biomarkers could be a rapid option for early diagnosis of the disease. OBJECTIVE: This study aimed to analyze some plasma biomarkers (amyloid-ß, tau, and lipids) in Mexican AD patients and control subjects with no associated neurodegenerative diseases. METHODS: Plasma amyloid-ß peptides (Aß40 and Aß42), total and phosphorylated tau protein (T-tau and P-tau), and cholesterol and triglyceride levels were quantified by enzyme-linked immunosorbent assay in AD patients and control subjects. RESULTS: In Mexican AD patients, we found significantly lower levels of Aß42 (p < 0.05) compared to the control group. In contrast, significantly higher levels of P-tau (p < 0.05) and triglycerides (p < 0.05) were observed in AD patients compared to controls. Furthermore, a significant correlation was found between the severity of dementia and plasma P-tau levels, Aß42/Aß40 and P-tau/T-tau ratios, and triglycerides concentrations. This correlation increased gradually with cognitive decline. CONCLUSION: The detection of these plasma biomarkers is an initial step in searching for a timely, less invasive, and cost-efficient diagnosis in Mexicans.

S-allyl Cysteine, a Garlic Compound, Produces an Antidepressant-Like Effect and Exhibits Antioxidant Properties in Mice.

Depression is a psychiatric disorder, and oxidative stress is a significant mechanism of damage in this mood disorder. It is characterized by an enhancement of oxidative stress markers and low concentrations of endogenous antioxidants, or antioxidants enzymes. This suggests that antioxidants could have an antidepressant effect. S-allyl cysteine (SAC) is a compound with antioxidant action or free radical scavenger capacity. The purpose of the current research was to evaluate the antidepressant-like effect as well as the antioxidant role of SAC on a preclinical test, using the Porsolt forced swim test (FST). SAC (30, 70, 120, or 250 mg/kg, ip) was administered to male BALB/c mice daily for 17 days, followed by the FST at day 18. Oxidative stress markers (reactive oxygen species, superoxide production, lipid peroxidation, and antioxidant enzymes activities) were analyzed in the midbrain, prefrontal cortex, and hippocampus. SAC (120 mg/kg) attenuated the immobility scores (44%) in the FST, and protection was unrelated to changes in locomotor activity. This antidepressant-like effect was related to decreased oxidative stress, as indicated by lipid peroxidation and manganese-superoxide dismutase (Mn-SOD) activity in the hippocampus. SAC exerts an antidepressant-like effect that correlated, in part, with preventing oxidative damage in hippocampus.

Association of polymorphisms and reduced expression levels of the NR4A2 gene with Parkinson's disease in a Mexican population.

INTRODUCTION: The NR4A2 transcription factor is important in the development, survival and phenotype of dopaminergic neurons and it is postulated as a possible biomarker for Parkinson's disease (PD). Therefore, our aim was to analyze in a sample of a Mexican population with idiopathic PD, mutations (in two hotspot mutation regions) and two polymorphisms (rs34884856 in promotor and rs35479735 intronic regions) of the NR4A2 gene. We also evaluate the levels of NR4A2 gene expression in peripheral blood for a Mexican population, and identify whether they are associated with NR4A2 gene polymorphisms. METHODS: We conducted a case-control study, which included 227 idiopathic PD cases and 454 unrelated controls. Genetic variants of the NR4A2 gene were genotyped by high-resolution melting (HRM) and validated by an automated sequencing method. The gene expression was performed in peripheral blood using a real-time polymerase chain reaction. RESULTS: The rs35479735 polymorphism was associated with a higher risk of developing PD. In addition, NR4A2 gene expression was significantly decreased in patients with PD. Linkage disequilibrium analysis showed a haplotype H4 (3C-3G) that showed lower levels of expression, and contained the risk alleles for both polymorphisms. CONCLUSIONS: In summary, this is the first study in a Mexican population that considers the analysis of NR4A2 in patients with PD. An association was identified between genotype and mRNA expression levels of NR4A2 in patients with PD. These results suggest that polymorphisms and expression of the NR4A2 gene could play an important role in the risk of developing PD in Mexican populations.

Functional integrity in vitro of hematopoietic progenitor cells from patients with chronic myeloid leukemia that have achieved hematological remission after different therapeutic procedures.

In this study, we have assessed the in vitro growth of hematopoietic progenitor cells (HPC) from chronic myeloid leukemia (CML) patients that have recovered after different treatments. Bone marrow cells were obtained from 33 CML patients, including patients at diagnosis, before treatment (n=12), and patients that have achieved hematological remission (and in most cases a major cytogenetic response) after different therapeutic procedures (n=21), including patients treated with Interferon-alpha (IFN; n=5), imatinib mesylate (IMATINIB; n=8) and patients that received an allogeneic hematopoietic cell transplant (HCT; n=8). Marrow cells were enriched for CD34(+) cells and cultured in a serum- and stroma-free liquid culture system, supplemented with a combination of 8 recombinant cytokines. Normal samples were studied as controls. HPC from CML patients before therapy showed deficient proliferation and expansion potentials in culture (140-fold increase in nucleated cell number and 1.3-fold increase in colony-forming cell number) as compared to normal progenitors (1200-fold increase in nucleated cell number and 25-fold increase in colony-forming cell number). In contrast, HPC from patients treated with IMATINIB showed growth potentials similar to those of normal progenitors. Progenitors from patients after HCT also showed significant proliferation and expansion capacities. Interestingly, progenitors from IFN-treated patients showed proliferation and expansion kinetics similar to those of cells from untreated patients. These results indicate that, although treatment of CML patients with IFN, IMATINIB or HCT resulted in complete hematological remission (and a major cytogenetic response), only patients treated with IMATINIB and, to a lesser extent, with HCT showed a full hematopoietic recovery, as determined by the in vitro growth of HPC in our culture system.

Ginkgo biloba Extract 761: A Review of Basic Studies and Potential Clinical Use in Psychiatric Disorders.

Ginkgo biloba extract 761 (EGb 761) is a well-defined extract obtained from Ginkgo biloba leaves according to a standardized method. It has been used extensively for the treatment of diseases related to the central nervous system including neurosensory disturbances, cerebrovascular insufficiency, peripheral vascular disturbances, and degenerative dementia. The potential use of EGb 761 has also been suggested for the treatment of psychiatric disorders such as anxiety and depression, which is discussed in the current review. These disorders constitute a global epidemic with serious economic and social consequences. Current available treatments with synthetic drugs may have some disadvantages and undesired side effects. There are diverse natural extracts that have been used for the treatment of psychiatric disorders due to their therapeutic action and low rate of side effects, such as EGb 761. EGb 761 has the ability to produce neuroprotection due to its chemical composition and the synergy of its components. We describe several neuroprotective mechanisms of action of EGb 761 such as antioxidant effects, modulation of neurotransmission, neuroendocrine regulation, and upregulation of neurotrophic factors, which underlie its potential therapeutic effect on psychiatric disorders. Furthermore, we discuss the therapeutic effects of EGb 761 both in animal models of psychiatric disorders and in clinical studies that include these pathologies. We focus on depression, anxiety, and schizophrenia, as well as the therapeutic action of EGb 761 on dementia in comorbidity with psychiatric disorders. In the current review, we propose thef potential use of EGb 761, alone or combined with current medication treatment, for psychiatric disorders.

S-Allylcysteine, a garlic compound, protects against oxidative stress in 1-methyl-4-phenylpyridinium-induced parkinsonism in mice.

S-Allylcysteine (SAC), the most abundant organosulfur compound in aged garlic extract, has multifunctional activity via different mechanisms and neuroprotective effects that are exerted probably via its antioxidant or free radical scavenger action. The 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-treated mouse has been the most widely used model for assessing neuroprotective agents for Parkinson's disease. 1-Methyl-4-phenylpyridinium (MPP(+)) is the stable metabolite of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine, and it causes nigrostriatal dopaminergic neurotoxicity. Previous studies suggest that oxidative stress, via free radical production, is involved in MPP(+)-induced neurotoxicity. Here, we report on the neuroprotective effect of SAC against oxidative stress induced by MPP(+) in the striatum of C57BL/6J mice. Mice were pretreated with SAC (125 mg/kg ip) daily for 17 days, followed by administration of MPP(+) (0.72 mg/kg icv), and were sacrificed 24 h later to evaluate lipid peroxidation, different antioxidant enzyme activities, spontaneous locomotor activity and dopamine (DA) content. MPP(+) administration resulted in a significant decrease in DA levels in the striatum. Mice receiving SAC (125 mg/kg ip) had significantly attenuated MPP(+)-induced loss of striatal DA levels (32%). The neuroprotective effect of SAC against MPP(+) neurotoxicity was associated with blocked (100% of protection) of lipid peroxidation and reduction of superoxide radical production - indicated by an up-regulation of Cu-Zn-superoxide dismutase activity - both of which are indices of oxidative stress. Behavioral analyses showed that SAC improved MPP(+)-induced impairment of locomotion (35%). These findings suggest that in mice, SAC attenuates MPP(+)-induced neurotoxicity in the striatum and that an antioxidant effect against oxidative stress may be partly responsible for its observed neuroprotective effects.