Induced Pluripotent Stem Cells and Organoids in Advancing Neuropathology Research and Therapies.

This review delves into the groundbreaking impact of induced pluripotent stem cells (iPSCs) and three-dimensional organoid models in propelling forward neuropathology research. With a focus on neurodegenerative diseases, neuromotor disorders, and related conditions, iPSCs provide a platform for personalized disease modeling, holding significant potential for regenerative therapy and drug discovery. The adaptability of iPSCs, along with associated methodologies, enables the generation of various types of neural cell differentiations and their integration into three-dimensional organoid models, effectively replicating complex tissue structures in vitro. Key advancements in organoid and iPSC generation protocols, alongside the careful selection of donor cell types, are emphasized as critical steps in harnessing these technologies to mitigate tumorigenic risks and other hurdles. Encouragingly, iPSCs show promising outcomes in regenerative therapies, as evidenced by their successful application in animal models.

Influence of Zika virus on the cytotoxicity, cell adhesion, apoptosis and inflammatory markers of glioblastoma cells.

Glioblastoma (GBM) is one of the most common types of brain tumor in adults. Despite the availability of treatments for this disease, GBM remains one of the most lethal and difficult types of tumors to treat, and thus, a majority of patients die within 2 years of diagnosis. Infection with Zika virus (ZIKV) inhibits cell proliferation and induces apoptosis, particularly in developing neuronal cells, and thus could potentially be considered an alternative for GBM treatment. In the present study, two GBM cell lines (U-138 and U-251) were infected with ZIKV at different multiplicities of infection (0.1, 0.01 and 0.001), and cell viability, migration, adhesion, induction of apoptosis, interleukin levels and CD14/CD73 cell surface marker expression were analyzed. The present study demonstrated that ZIKV infection promoted loss of cell viability and increased apoptosis in U-138 cells, as measured by MTT and triplex assay, respectively. Changes in cell migration, as determined by wound healing assay, were not observed; however, the GBM cell lines exhibited an increase in cell adhesion when compared with non-tumoral cells (Vero). The Luminex immunoassay showed a significant increase in the expression levels of IL-4 specifically in U-251 cells (MOI 0.001) following exposure to ZIKV. There was no significant change in the expression levels of IFN-γ upon ZIKV infection in the cell lines tested. Furthermore, a marked increase in the percentage of cells expressing the CD14 surface marker was observed in both GBM cell lines compared with in Vero cells; and significantly increased CD73 expression was observed particularly in U-251 cells, when compared with uninfected cells. These findings indicate that ZIKV infection could lead to reduced cell viability, elevated CD73 expression, improved cellular adherence, and higher rates of apoptosis in glioblastoma cells. Further studies are required to explore the potential use of ZIKV in the treatment of GBM.

Exploring CD39 and CD73 Expression as Potential Biomarkers in Prostate Cancer.

Prostate cancer (PC) is the most diagnosed tumor in males and ranks as the second leading cause of male mortality in the western world. The CD39 and CD73 enzymes play a crucial role in cancer regulation by degrading nucleotides and forming nucleosides. This study aimed to investigate the expression of the CD39 and CD73 enzymes as potential therapeutic targets for PC. The initial part of this study retrospectively analyzed tissue samples from 23 PC patients. Using the TissueFAXSTM cytometry platform, we found significantly higher levels of CD39-labeling its intensity compared to CD73. Additionally, we observed a correlation between the Gleason score and the intensity of CD39 expression. In the prospective arm, blood samples were collected from 25 patients at the time of diagnosis and after six months of treatment to determine the expression of CD39 and CD73 in the serum extracellular vesicles (EVs) and to analyze nucleotide hydrolysis. Notably, the expression of CD39 in the EVs was significantly increased compared to the CD73 and/or combined CD39/CD73 expression levels at initial collection. Furthermore, our results demonstrated positive correlations between ADP hydrolysis and the transurethral resection and Gleason score. Understanding the role of ectonucleotidases is crucial for identifying new biomarkers in PC.

Neural stem cells persist to generate new neurons in the hippocampus of adult and aged human brain - Fiction or accurate?

Adult neurogenesis, comprising the generation, differentiation and integration of new neurons in the mature brain, has emerged as a dynamic area of research over decades. The discovery of adult neurogenesis was a paradigm shift to comprehend mechanisms underlying brain plasticity, cognitive function, and neurological disorders. This review deliberates significant findings from articles published over four decades on adult neurogenesis, highlighting key milestones, methodological advances, and controversies that have shaped our comprehension of the phenomenon of adult neurogenesis. Early skepticism gave way to a rich body of evidence via various reliable approaches. Studies on neurogenic niches, microenvironmental factors, molecular regulators, and functional implications have uncovered the involvement of adult neurogenesis in learning, memory, mood, and even neurological and neurodegenerative conditions. Despite significant progress, several questions still need to be answered, including the exact contributions of new neurons to brain function, their integration into existing circuits, and the impact of enhancing adult neurogenesis in the human hippocampus. While the existence of robust neurogenesis in the adult and aged human hippocampus is yet to be confirmed, this review highlights evidence from a significant number of studies supporting the persistence of hippocampal neurogenesis during adulthood and aging in humans, including in some neurological conditions, such as epilepsy and Alzheimer's disease. Nonetheless, additional large-scale studies using single cell-RNA-seq, single nucleus-RNA-seq, and spatial transcriptomics are critical to validate the presence and contribution of hippocampal neurogenesis in the pathophysiology of various neurological and neurodegenerative conditions at different stages of the disease. There is also a need to develop standardized protocols for analyzing postmortem hippocampal tissues for cellular and molecular analyses.

WNT pathway in focal cortical dysplasia compared to perilesional nonlesional tissue in refractory epilepsies.

BACKGROUND: Focal cortical dysplasia (FCD) is a malformation of cortical development that causes medical refractory seizures, and one of the main treatments may be surgical resection of the affected area of the brain. People affected by FCD may present with seizures of variable severity since childhood. Despite many medical treatments available, only surgery can offer cure. The pathophysiology of the disease is not yet understood; however, it is known that several gene alterations may play a role. The WNT/ß-catenin pathway is closely related to the control and balance of cell proliferation and differentiation in the central nervous system. The aim of this study was to explore genes related to the WNT/ß-catenin pathway in lesional and perilesional brain tissue in patients with FCD type II. METHODS: Dysplastic and perilesional tissue from the primary dysplastic lesion of patients with FCD type IIa were obtained from two patients who underwent surgical treatment. The analysis of the relative expression of genes was performed by a qRT-PCR array (super array) containing 84 genes related to the WNT pathway. RESULTS: Our results suggest the existence of molecular alteration in some genes of the WNT pathway in tissue with dysplastic lesions and of perilesional tissue. We call this tissue of normal-appearing adjacent cortex (NAAC). Of all genes analyzed, a large number of genes show similar behavior between injured, perilesional and control tissues. However, some genes have similar characteristics between the perilesional and lesional tissue and are different from the control brain tissue, presenting the perilesional tissue as a molecularly altered material. CONCLUSION: Our results suggest that the perilesional area after surgical resection of tissue with cortical dysplasia presents molecular changes that may play a role in the recurrence of seizures in these patients. The perilesional tissue should receive expanded attention beyond the somatic mutations described and associated with FCD, such as mTOR, for example, to new signaling pathways that may play a crucial role in seizure recurrence.

Guillain-Barré syndrome associated with COVID-19: A systematic review.

With the outbreak of coronavirus disease 2019 (COVID-19), the whole world was impacted by a pandemic. With the passage of time and knowledge about the dynamics and viral propagation of this disease, the short-, medium- and long-term repercussions are still being discovered. During this period, it has been learned that various manifestations of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can affect the nervous system. In recent months, a variety of studies and case reports have proposed an association between COVID-19 and Guillain-Barré syndrome (GBS). The present work aims to systematically review the publications available to date to verify the relationship between these two pathologies and the characteristics of post-COVID GBS. There were 156 studies included in this work, resulting in a total of 436 patients. The findings show a mean age of the patients of 61,38 years and a male majority. The GBS symptoms began on average 19 days after the onset of COVID-19 infection. Regarding GBS, the main manifestations found included generalized weakness, reflex reduction, facial paresis/paralysis and hypoesthesia. As expected, the most common result in cerebrospinal fluid (CSF) analysis was albuminocytological dissociation. A pattern of blood analysis findings common to all patients was not observed due to non-standardization of case reports. Regarding electrodiagnostic studies, acute inflammatory demyelinating polyneuropathy (AIDP) appeared as the most common subtype of GBS in this study. There have been reports, to a lesser extent, of acute motor axonal neuropathy (AMAN), acute sensorimotor axonal neuropathy (AMSAN), the pharyngeal-cervical-brachial variant (PCB), and Miller-Fisher syndrome (MFS). The GBS treatment used was mainly intravenous immunoglobulin (IVIG) and plasma exchange (PLEX). Therefore, the present study reports a high prevalence of hospitalization and intensive care units ICU admissions, conjecturing a relationship between the development of GBS and the severity of COVID-19. Despite the severity, most patients showed improvement in GBS symptoms after treatment, and their residual symptoms did not include motor involvement. Therefore, the development of GBS seems to be related to COVID-19 infection, as reported by the present systematic review.

Environmental pollution and attention deficit hyperactivity disorder: A meta-analysis of cohort studies.

There is already knowledge of the extensive risk factors for attention deficit hyperactivity disorder (ADHD) and recent studies suggest that environmental pollution may contribute to an increase in the incidence of the disorder. The aim of our study was to perform a systematic review and meta-analysis of the risk of ADHD in people younger than 18 years old after exposure to environmental pollution. We searched the MEDLINE, Embase, SciELO, CINAHL, LILACS, Cochrane Central, and Web of Science databases and investigated the grey literature from inception until May 31, 2021. All cohort studies that provided data on exposure to environmental pollutants and ADHD in children and adolescents aged from zero to 18 years old were included. Two reviewers independently selected the studies and applied the quality criteria. If there was a divergence, a third reviewer contributed to the final decision. For the meta-analysis, risk ratios and their confidence intervals were calculated with the MetaXL 5.3 program, using the random effects model. In total, 21 articles were included in this systematic review, and 18 studies met the criteria for the meta-analysis, involving 134,619 participants. The meta-analysis suggested that children exposed to higher levels of heavy metal (RR: 2.41, 95% CI: 1.49-3.90), with low heterogeneity (I2 = 39%), and lead (RR: 2.37, 95% CI: 1.28-4.40), with moderate heterogeneity (I2 = 54%), are at greater risk of developing ADHD than those exposed to lower levels. This meta-analysis suggests that children exposed to higher levels of lead and heavy metal pollution are at greater risk of developing ADHD than those exposed to lower levels.

When to test for COVID-19 using real-time reverse transcriptase polymerase chain reaction: a systematic review.

OBJECTIVES: The aim of this study was to evaluate the time in days between symptom onset and first positive real-time reverse transcriptase polymerase chain reaction (RT-PCR) result for COVID-19. METHODS: This systematic review was conducted in the MEDLINE (PubMed), Embase, and Scopus databases using the following descriptors: "COVID-19", "SARS-CoV-2", "coronavirus", "RT-PCR", "real time PCR", and "diagnosis". RESULTS: The included studies were conducted in 31 different countries and reported on a total of 6831 patients. The median age of the participants was 49.95 years. The three most common symptoms were fever, cough, and dyspnea, which affected 4012 (58.68%), 3192 (46.69%), and 2009 patients (29.38%), respectively. Among the 90 included studies, 13 were prospective cohorts, 15 were retrospective cohorts, 36 were case reports, 20 were case series, and six were cross-sectional studies. The overall mean time between symptom onset and positive test result was 6.72 days. Fourteen articles were analyzed separately for the temporal profile of RT-PCR test results; the best performance was on days 22-24, when 98% of test results were positive. CONCLUSION: These findings corroborate the RT-PCR COVID-19 testing practices of some health units. In addition, the most frequently described symptoms of these patients can be considered the initial symptoms of infection and used in decision-making about RT-PCR testing.

Stem cell-based therapy for COVID-19 and ARDS: a systematic review.

Despite global efforts to establish effective interventions for coronavirus disease 2019 (COVID-19) and its major complications, such as acute respiratory distress syndrome (ARDS), the treatment remains mainly supportive. Hence, identifying an effective and safe therapy for severe COVID-19 is critical for saving lives. A significant number of cell-based therapies have been through clinical investigation. In this study, we performed a systematic review of clinical studies investigating different types of stem cells as treatments for COVID-19 and ARDS to evaluate the safety and potential efficacy of cell therapy. The literature search was performed using PubMed, Embase, and Scopus. Among the 29 studies, there were eight case reports, five Phase I clinical trials, four pilot studies, two Phase II clinical trials, one cohort, and one case series. Among the clinical studies, 21 studies used cell therapy to treat COVID-19, while eight studies investigated cell therapy as a treatment for ARDS. Most of these (75%) used mesenchymal stem cells (MSCs) to treat COVID-19 and ARDS. Findings from the analyzed articles indicate a positive impact of stem cell therapy on crucial immunological and inflammatory processes that lead to lung injury in COVID-19 and ARDS patients. Additionally, among the studies, there were no reported deaths causally linked to cell therapy. In addition to standard care treatments concerning COVID-19 management, there has been supportive evidence towards adjuvant therapies to reduce mortality rates and improve recovery of care treatment. Therefore, MSCs treatment could be considered a potential candidate for adjuvant therapy in moderate-to-severe COVID-19 cases and compassionate use.

Left Hemisphere Lateralization of Epileptic Focus Can Be More Frequent in Temporal Lobe Epilepsy Surgical Patients with No Consensus Associated with Depression Lateralization.

Temporal lobe epilepsy (TLE) is considered to be the most common form of epilepsy, and it has been seen that most patients are refractory to antiepileptic drugs. A strong association of this ailment has been established with psychiatric comorbidities, primarily mood and anxiety disorders. The side of epileptogenic may contribute to depressive and anxiety symptoms; thus, in this study, we performed a systematic review to evaluate the prevalence of depression in TLE in surgical patients. The literature search was performed using PubMed/Medline, Web of Science, and PsycNet to gather data from inception until January 2019. The search strategy was related to TLE, depressive disorder, and anxiety. After reading full texts, 14 articles meeting the inclusion criteria were screened. The main method utilized for psychiatric diagnosis was Diagnostic and Statistical Manual of Mental Disorders/Structured Clinical Interview for DSM. However, most studies failed to perform the neuropsychological evaluation. For those with lateralization of epilepsy, focus mostly occurred in the left hemisphere. For individual depressive diagnosis, 9 studies were evaluated, and 5 for anxiety. Therefore, from the data analyzed in both situations, no diagnosis was representative in preoperative and postoperative cases. In order to estimate the efficacy of surgery in the psychiatry episodes and its relation to seizure control, the risk of depression and anxiety symptoms in epileptic patients need to be determined before surgical procedures. Rigorous preoperative and postoperative evaluation is essential for psychiatry conditions in patients with refractory epilepsy candidates for surgery.

Case Report: Placental Maternal Vascular Malperfusion Affecting Late Fetal Development and Multiorgan Infection Caused by SARS-CoV-2 in Patient With PAI-1 4G/5G Polymorphism.

Background: Pregnant women are susceptible to the novel coronavirus (SARS-CoV-2), and the consequences for the fetus are still uncertain. Here, we present a case of a pregnant woman with subclinical hypothyroidism and a plasminogen activator inhibitor type 1 (PAI-1) 4G/5G polymorphism who was infected with SARS-CoV-2 at the end of the third trimester of pregnancy, with unexpected evolution of death of the newborn 4 days postpartum. Methods: Nested PCR was performed to detect the virus, followed by ssDNA sequencing. Results: Transplacental transmission of SARS-CoV-2 can cause placental inflammation, ischemia, and neonatal viremia, with complications such as preterm labor and damage to the placental barrier in patients with PAI-1 4G/5G polymorphism. Conclusion: We showed a newborn with several damages potentially caused due to the PAI-1 polymorphisms carried by the mother infected with SARS-CoV-2 during pregnancy.

Extracellular vesicles from human iPSC-derived neural stem cells: miRNA and protein signatures, and anti-inflammatory and neurogenic properties.

Grafting of neural stem cells (NSCs) derived from human induced pluripotent stem cells (hiPSCs) has shown promise for brain repair after injury or disease, but safety issues have hindered their clinical application. Employing nano-sized extracellular vesicles (EVs) derived from hiPSC-NSCs appears to be a safer alternative because they likely have similar neuroreparative properties as NSCs and are amenable for non-invasive administration as an autologous or allogeneic off-the-shelf product. However, reliable methods for isolation, characterization and testing the biological properties of EVs are critically needed for translation. We investigated signatures of miRNAs and proteins and the biological activity of EVs, isolated from hiPSC-NSCs through a combination of anion-exchange chromatography (AEC) and size-exclusion chromatography (SEC). AEC and SEC facilitated the isolation of EVs with intact ultrastructure and expressing CD9, CD63, CD81, ALIX and TSG 101. Small RNA sequencing, proteomic analysis, pathway analysis and validation of select miRNAs and proteins revealed that EVs were enriched with miRNAs and proteins involved in neuroprotective, anti-apoptotic, antioxidant, anti-inflammatory, blood-brain barrier repairing, neurogenic and Aß reducing activities. Besides, EVs comprised miRNAs and/or proteins capable of promoting synaptogenesis, synaptic plasticity and better cognitive function. Investigations using an in vitro macrophage assay and a mouse model of status epilepticus confirmed the anti-inflammatory activity of EVs. Furthermore, the intranasal administration of EVs resulted in the incorporation of EVs by neurons, microglia and astrocytes in virtually all adult rat and mouse brain regions, and enhancement of hippocampal neurogenesis. Thus, biologically active EVs containing miRNAs and proteins relevant to brain repair could be isolated from hiPSC-NSC cultures, making them a suitable biologic for treating neurodegenerative disorders.

Long-term changes in metabolic brain network drive memory impairments in rats following neonatal hypoxia-ischemia.

BACKGROUND AND PURPOSE: Hypoxia and cerebral ischemia (HI) events are capable of triggering important changes in brain metabolism, including glucose metabolism abnormalities, which may be related to the severity of the insult. Using positron emission microtomography (microPET) with [18F]fluorodeoxyglucose (18F-FDG), this study proposes to assess abnormalities of brain glucose metabolism in adult rats previously submitted to the neonatal HI model. We hypothesize that cerebral metabolic outcomes will be associated with cognitive deficits and magnitude of brain injury. METHODS: Seven-day-old rats were subjected to an HI model, induced by permanent occlusion of the right common carotid artery and systemic hypoxia. 18F-FDG-microPET was used to assess regional and whole brain glucose metabolism in rats at 60 postnatal days (PND 60). An interregional cross-correlation matrix was utilized to construct metabolic brain networks (MBN). Rats were also subjected to the Morris Water Maze (MWM) to evaluate spatial memory and their brains were processed for volumetric evaluation. RESULTS: Brain glucose metabolism changes were observed in adult rats after neonatal HI insult, limited to the right brain hemisphere. However, not all HI animals exhibited significant cerebral hypometabolism. Hippocampal glucose metabolism was used to stratify HI animals into HI hypometabolic (HI-h) and HI non-hypometabolic (HI non-h) groups. The HI-h group had drastic MBN disturbance, cognitive deficit, and brain tissue loss, concomitantly. Conversely, HI non-h rats had normal brain glucose metabolism and brain tissue preserved, but also presented MBN changes and spatial memory impairment. Furthermore, data showed that brain glucose metabolism correlated with cognitive deficits and brain volume outcomes. CONCLUSIONS: Our findings demonstrated that long-term changes in MBN drive memory impairments in adult rats subjected to neonatal hypoxic ischemia, using in vivo imaging microPET-FDG. The MBN analyses identified glucose metabolism abnormalities in HI non-h animals, which were not detected by conventional 18F-FDG standardized uptake value (SUVr) measurements. These animals exhibited a metabolic brain signature that may explain the cognitive deficit even with no identifiable brain damage.

The Interstitial System of the Brain in Health and Disease.

The brain interstitial fluid (ISF) and the cerebrospinal fluid (CSF) cushion and support the brain cells. The ISF occupies the brain interstitial system (ISS), whereas the CSF fills the brain ventricles and the subarachnoid space. The brain ISS is an asymmetrical, tortuous, and exceptionally confined space between neural cells and the brain microvasculature. Recently, with a newly developed in vivo measuring technique, a series of discoveries have been made in the brain ISS and the drainage of ISF. The goal of this review is to confer recent advances in our understanding of the brain ISS, including its structure, function, and the various processes mediating or disrupting ISF drainage in physiological and pathological conditions. The brain ISF in the deep brain regions has recently been demonstrated to drain in a compartmentalized ISS instead of a highly connected system, together with the drainage of ISF into the cerebrospinal fluid (CSF) at the surface of the cerebral cortex and the transportation from CSF into cervical lymph nodes. Besides, accumulation of tau in the brain ISS in conditions such as Alzheimer's disease and its link to the sleep-wake cycle and sleep deprivation, clearance of ISF in a deep sleep via increased CSF flow, novel approaches to remove beta-amyloid from the brain ISS, and obstruction to the ISF drainage in neurological conditions are deliberated. Moreover, the role of ISS in the passage of extracellular vesicles (EVs) released from neural cells and the rapid targeting of therapeutic EVs into neural cells in the entire brain following an intranasal administration, and the promise and limitations of ISS based drug delivery approaches are discussed.

Analysis of genes involved in cell proliferation, adhesion, and control of apoptosis during embryonic neurogenesis in Induced Pluripotent Stem Cells (iPSCs) from patients with Focal Cortical Dysplasia.

Focal cortical dysplasia (FCD) is a malformation of cortical development which is strongly associated with drug-refractory epilepsy. Certain studies have demonstrated an increase in mTOR signaling in patients with FCD on the basis of observation of phosphorylated molecules. The aim of the present study was to verify the differences in genes involved in cell proliferation, adhesion, and control of apoptosis during embryonic neurogenesis in iPSCs derived from the Focal Cortical Dysplasia. Fibroblasts were obtained from the skin biopsies of patients with FCD (n = 2) and controls (n = 2). iPSCs were generated by exposing the fibroblasts to viral vectors that contained the Yamanaka factors (OCT4, SOX2, KLF4, and c-MYC genes) responsible for promoving cell reprogramation. The fibroblasts and iPSCs were tested during different phases of neurodifferentiation for migration capacity and expression of the genes involved in the PI3K pathway. Fibroblasts of patients with FCD migrated with greater intensity during the first two time points of analyses. iPSCs did not exhibit any difference in cell migration between the groups. Fibroblasts, brain tissue, and iPSCs of the patients with FCD exhibited a significant reduction in the relative expression values of 4EBP-1. During neurodevelopment, the iPSCs from patients with FCD exhibited a reduction in the expression of cIAP-1, cIAP-2, PI3K, ß-Catenin and 4EBP-1 gene. We suggest that the differences observed in the migration potential of adult cells and in the gene expression related to the fundamental processes involved in normal brain development during the neurodifferentiation process might be associated with cortical alteration in the patients with FCD.

Evaluation of miR-135a/b expression in endometriosis lesions.

The pathogenesis of endometriosis is not clear; however, microRNAs (miRNAs/miRs) are involved in the pathogenesis. miRNAs are short noncoding RNAs involved in post-transcriptional regulation of gene expression by silencing the expression of target genes. The expression of miR-135a/b is associated with endometrial receptivity and implantation; the expression is also associated with the expression of certain genes, including homeobox protein Hox-A10 (HOXA-10). The present study investigated the expression of miR-135a/b in eutopic and ectopic endometrium tissues throughout the different phases of the menstrual cycle. Samples of ectopic endometriosis lesions and eutopic endometrium tissue from 23 patients who underwent laparoscopic surgery were obtained and analyzed. miRNA was extracted and the expression levels of miR-135a/b were determined by reverse transcription quantitative polymerase chain reaction assays using U6 as a housekeeping control. The expression levels of miR-135a and miR-135b in endometriosis lesions were decreased compared with the levels in endometrium tissue. However, miR-135a/b expression levels were increased in the secretory phase compared with the proliferative phase in endometriosis lesions. The increased expression of miR-135a/b during the secretory phase compared with the proliferative phase suggested that these genes serve a determinant role in the homeostasis of reproductive tissue. Therefore, the expression of genes may affect endometrial functioning, impairing embryo implantation.

A Model of Chronic Temporal Lobe Epilepsy Presenting Constantly Rhythmic and Robust Spontaneous Seizures, Co-morbidities and Hippocampal Neuropathology.

Many animal prototypes illustrating the various attributes of human temporal lobe epilepsy (TLE) are available. These models have been invaluable for comprehending multiple epileptogenic processes, modifications in electrophysiological properties, neuronal hyperexcitability, neurodegeneration, neural plasticity, and chronic neuroinflammation in TLE. Some models have also uncovered the efficacy of new antiepileptic drugs or biologics for alleviating epileptogenesis, cognitive impairments, or spontaneous recurrent seizures (SRS). Nonetheless, the suitability of these models for testing candidate therapeutics in conditions such as chronic TLE is debatable because of a lower frequency of SRS and an inconsistent pattern of SRS activity over days, weeks or months. An ideal prototype of chronic TLE for investigating novel therapeutics would need to display a large number of SRS with a dependable frequency and severity and related co-morbidities. This study presents a new kainic acid (KA) model of chronic TLE generated through induction of status epilepticus (SE) in 6-8 weeks old male F344 rats. A rigorous characterization in the chronic epilepsy period validated that the animal prototype mimicked the most salient features of robust chronic TLE. Animals displayed a constant frequency and intensity of SRS across weeks and months in the 5th and 6th month after SE, as well as cognitive and mood impairments. Moreover, SRS frequency displayed a rhythmic pattern with 24-hour periodicity and a consistently higher number of SRS in the daylight period. Besides, the model showed many neuropathological features of chronic TLE, which include a partial loss of inhibitory interneurons, reduced neurogenesis with persistent aberrant migration of newly born neurons, chronic neuroinflammation typified by hypertrophied astrocytes and rod-shaped microglia, and a significant aberrant mossy fiber sprouting in the hippocampus. This consistent chronic seizure model is ideal for investigating the efficacy of various antiepileptic drugs and biologics as well as understanding multiple pathophysiological mechanisms underlying chronic epilepsy.

Umbilical Mononuclear Cells and Fibroblast Interaction Downregulate the Expression of Cell Cycle Negative Control Genes.

The human umbilical cord blood (HUCB) is an excellent source of adult stem cells, having the benefit of being younger than the bone marrow stem cells. The role of stem cells in the lesion repair mechanism is still being studied. We evaluated the capability of HUCB to interfere into the fibroblast dedifferentiation plasticity through cocultivation. Direct and indirect cocultures were maintained for 24, 48, and 72 hours. Coculture viability was evaluated by MTT assay. The messenger RNA was extracted, and the expression of p16 and p21 genes was estimated by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR). The direct or indirect contact did not interfere with fibroblast cell viability. However, these direct and indirect contacts reduced the expression of p16 and p21 genes. A sigmoidal curve was applied to adjust gene expression against time, and a mathematical function was established for gene expression according to cell culture type. These results suggest that the differentiated cells were influenced by immature cells (HUCB) either by the direct contact or by signaling molecules, which alter their behavior and plasticity. Therefore our data may contribute to paracrine effects other than the commonly known to be responsible for the repair of lesions in stem cell therapy.

Depression comorbidity in epileptic rats is related to brain glucose hypometabolism and hypersynchronicity in the metabolic network architecture.

OBJECTIVE: Temporal lobe epilepsy (TLE) is one of the most common types of epilepsy syndromes in the world. Depression is an important comorbidity of epilepsy, which has been reported in patients with TLE and in different experimental models of epilepsy. However, there is no established consensus on which brain regions are associated with the manifestation of depression in epilepsy. Here, we investigated the alterations in cerebral glucose metabolism and the metabolic network in the pilocarpine-induced rat model of epilepsy and correlated it with depressive behavior during the chronic phase of epilepsy. METHODS: Fluorodeoxyglucose (18 F-FDG) was used to investigate the cerebral metabolism, and a cross-correlation matrix was used to examine the metabolic network in chronically epileptic rats using micro-positron emission tomography (microPET) imaging. An experimental model of epilepsy was induced by pilocarpine injection (320 mg/kg, ip). Forced swim test (FST), sucrose preference test (SPT), and eating-related depression test (ERDT) were used to evaluate depression-like behavior. RESULTS: Our results show an association between epilepsy and depression comorbidity based on changes in both cerebral glucose metabolism and the functional metabolic network. In addition, we have identified a significant correlation between brain glucose hypometabolism and depressive-like behavior in chronically epileptic rats. Furthermore, we found that the epileptic depressed group presents a hypersynchronous brain metabolic network in relation to the epileptic nondepressed group. SIGNIFICANCE: This study revealed relevant alterations in glucose metabolism and the metabolic network among the brain regions of interest for both epilepsy and depression pathologies. Thus it seems that depression in epileptic animals is associated with a more diffuse hypometabolism and altered metabolic network architecture and plays an important role in chronic epilepsy.