Layered double hydroxides (LDHs) as efficient and safe carriers for miRNA inhibitors: In vitro and in vivo assessment of biocompatibility.

Layered double hydroxides (LDHs) have been employed as nano-sized carriers for therapeutic/bio-active molecules, including small interfering RNAs (siRNAs). However, the potential of LDHs nanoparticles for an efficient and safe antisense oligonucleotide (AMO) delivery still requires studies. In this research, we have tested the suitability of a Mg-Al-LDH-based nanocarrier loaded with a miRNA-196b-5p inhibitor. LDHs (and LDH-Oligo complex) were synthesized by the coprecipitation method followed by physicochemical characterization as hydrodynamic size, surface charge, crystallinity, and chemical groups. Thymic endothelial cell line (tEnd.1) were transfected with LDH-Oligo and were evaluated for i. cell viability by MTT, trypan blue, and propidium iodide assays; ii. transfection efficiency by flow cytometry, and iii. depletion of miRNA-196b-5p by RT-qPCR. In addition, Drosophila melanogaster larvae were fed LDHs and evaluated for: i. larval motility; ii. pupation rate; iii. larval-pupal transition; iv. lethality, and v. emergence rate. We demonstrated that LDHs nanoparticles are stable in aqueous solutions and exhibit a regular hexagonal shape. The LDH-AMO complex showed a transfection efficiency of 93.95 ± 2.15 % and induced a significant depletion of miRNA-196b-5p 48h after transfection. No cytotoxic effects were detected in tEnd.1 cells at concentrations up to 50 µg/ml, as well as in Drosophila exposed up to 500 µg of LDH. In conclusion, our data suggest that LDHs are biocompatible and efficient carriers for miRNA inhibitors and can be used as a viable and effective tool in functional miRNA inhibition assays.

Iron and aluminum ore mining pollution induce oxidative and tissue damage on fruit-eating bats from the Atlantic Forest.

Mining, a vital industry for economic growth, poses significant environmental pollution challenges. Failures in tailings dam containment have caused environmental contamination and raised concerns about preserving the globally significant biodiversity in the Atlantic Forest, which is under severe threat. Fruit-eating bats are key for forest regeneration as essential seed dispersers and pollinators. This study focuses on two keystone species, Artibeus lituratus and Sturnira lilium, exploring the effects of iron ore mining area (FEOA) and aluminum ore mining area (ALOA) on these bats, respectively, and comparing to individuals from a preserved Atlantic Forest fragment (FFA). Bats from FEOA showed higher Aluminum (Al), Calcium (Ca), Iron (Fe) and Barium (Ba) liver accumulation, as well as Ca and Fe muscle accumulation. These animals also showed higher liver and kidney oxidative damage associated with liver fibrosis and kidney inflammation. Brain and muscle also showed oxidative stress. Bats from ALOA showed higher Ca and Ba liver accumulation and Ca, Zinc (Zn), and Ba muscle accumulation, along with higher brain oxidative stress, liver fibrosis, and kidney inflammation. Our findings indicate that iron and aluminum ore mining activities cause adverse effects on bat tissues, posing a potential threat to biodiversity maintenance in the Atlantic Forest.

N-Formyl-Methionyl-Leucyl-Phenylalanine Plays a Neuroprotective and Anticonvulsant Role in Status Epilepticus Model.

Status epilepticus (SE) is described as continuous and self-sustaining seizures, which triggers hippocampal neurodegeneration, inflammation, and gliosis. N-formyl peptide receptor (FPR) has been associated with inflammatory process. N-formyl-methionyl-leucyl-phenylalanine (fMLP) peptide plays an anti-inflammatory role, mediated by the activation of G-protein-coupled FPR. Here, we evaluated the influence of fMLP peptides on the behavior of limbic seizures, memory consolidation, and hippocampal neurodegeneration process. Male Wistar rats (Rattus norvegicus) received microinjections of pilocarpine in hippocampus (H-PILO, 1.2 mg/µL, 1 µL) followed by fMLP (1 mg/mL, 1 µL) or vehicle (VEH, saline 0.9%, 1 µL). During the 90 min of SE, epileptic seizures were analyzed according to the Racine's Scale. After 24 h of SE, memory impairment was assessed by the inhibitory avoidance test and the neurodegeneration process was evaluated in hippocampal areas. There was no change in latency and number of wet dog shake (WDS) after administration of fMLP. However, our results showed that the intrahippocampal infusion of fMLP reduced the severity of seizures, as well as the number of limbic seizures. In addition, fMLP infusion protected memory dysfunction followed by SE. Finally, the intrahippocampal administration of fMLP attenuated the process of neurodegeneration in both hippocampi. Taken together, our data suggest a new insight into the functional role of fMLP peptides, with important implications for their potential use as a therapeutic agent for the treatment of brain disorders, such as epilepsy. Schematic drawing on the neuroprotective and anticonvulsant role of fMLP during status epilepticus. Initially, a cannula was implanted in hippocampus and pilocarpine/saline was administered into the hippocampus followed by fMLP/saline (A-C). fMLP reduced seizure severity and neuronal death in the hippocampus, as well as protecting against memory deficit (D).

Different types of Status Epilepticus may lead to similar hippocampal epileptogenesis processes.

About 1-2% of people worldwide suffer from epilepsy, which is characterized by unpredictable and intermittent seizure occurrence. Despite the fact that the exact origin of temporal lobe epilepsy is frequently unknown, it is frequently linked to an early triggering insult like brain damage, tumors, or Status Epilepticus (SE). We used an experimental approach consisting of electrical stimulation of the amygdaloid complex to induce two behaviorally and structurally distinct SE states: Type I (fully convulsive), with more severe seizure behaviors and more extensive brain damage, and Type II (partial convulsive), with less severe seizure behaviors and brain damage. Our goal was to better understand how the various types of SE impact the hippocampus leading to the development of epilepsy. Despite clear variations between the two behaviors in terms of neurodegeneration, study of neurogenesis revealed a comparable rise in the number of Ki-67 + cells and an increase in Doublecortin (DCX) in both kinds of SE.

SARS-CoV-2 and Hypertension: Evidence Supporting Invasion into the Brain Via Baroreflex Circuitry and the Role of Imbalanced Renin-Angiotensin-Aldosterone-System.

Hypertension is considered one of the most critical risk factors for COVID-19. Evidence suggests that SARS-CoV-2 infection produces intense effects on the cardiovascular system by weakening the wall of large vessels via vasa-vasorum. In this commentary, we propose that SARS-CoV-2 invades carotid and aortic baroreceptors, leading to infection of the nucleus tractus solitari (NTS) and paraventricular hypothalamic nucleus (PVN), and such dysregulation of NTS and PVN following infection causes blood pressure alteration at the central level. We additionally explored the hypothesis that SARS-CoV-2 favors the internalization of membrane ACE2 receptors generating an imbalance of the renin-angiotensin-aldosterone system (RAAS), increasing the activity of angiotensin II (ANG-II), disintegrin, and metalloproteinase 17 domain (ADAM17/TACE), eventually modulating the integration of afferents reaching the NTS from baroreceptors and promoting increased blood pressure. These mechanisms are related to the increased sympathetic activity, which leads to transient or permanent hypertension associated with SARS-CoV-2 invasion, contributing to the high number of deaths by cardiovascular implications.

Neuroprotective Effect of Exogenous Galectin-1 in Status Epilepticus.

Intrahippocampal pilocarpine microinjection (H-PILO) induces status epilepticus (SE) that can lead to spontaneous recurrent seizures (SRS) and neurodegeneration in rodents. Studies using animal models have indicated that lectins mediate a variety of biological activities with neuronal benefits, especially galectin-1 (GAL-1), which has been identified as an effective neuroprotective compound. GAL-1 is associated with the regulation of cell adhesion, proliferation, programmed cell death, and immune responses, as well as attenuating neuroinflammation. Here, we administrated GAL-1 to Wistar rats and evaluated the severity of the SE, neurodegenerative and inflammatory patterns in the hippocampal formation. Administration of GAL-1 caused a reduction in the number of class 2 and 4 seizures, indicating a decrease in seizure severity. Furthermore, we observed a reduction in inflammation and neurodegeneration 24 h and 15 days after SE. Overall, these results suggest that GAL-1 has a neuroprotective effect in the early stage of epileptogenesis and provides new insights into the roles of exogenous lectins in temporal lobe epilepsy (TLE).

Hydroelectrolytic Disorder in COVID-19 patients: Evidence Supporting the Involvement of Subfornical Organ and Paraventricular Nucleus of the Hypothalamus.

Multiple neurological problems have been reported in coronavirus disease-2019 (COVID-19) patients because severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) likely spreads to the central nervous system (CNS) via olfactory nerves or through the subarachnoid space along olfactory nerves into the brain's cerebrospinal fluid and then into the brain's interstitial space. We hypothesize that SARS-CoV-2 enters the subfornical organ (SFO) through the above routes and the circulating blood since circumventricular organs (CVOs) such as the SFO lack the blood-brain barrier, and infection of the SFO causes dysfunction of the hypothalamic paraventricular nucleus (PVN) and supraoptic nucleus (SON), leading to hydroelectrolytic disorder. SARS-CoV-2 can readily enter SFO-PVN-SON neurons because these neurons express angiotensin-converting enzyme-2 receptors and proteolytic viral activators, which likely leads to neurodegeneration or neuroinflammation in these regions. Considering the pivotal role of SFO-PVN-SON circuitry in modulating hydroelectrolyte balance, SARS-CoV-2 infection in these regions could disrupt the neuroendocrine control of hydromineral homeostasis. This review proposes mechanisms by which SARS-CoV-2 infection of the SFO-PVN-SON pathway leads to hydroelectrolytic disorder in COVID-19 patients.

Maternal crack cocaine use in rats leads to depressive- and anxiety-like behavior, memory impairment, and increased seizure susceptibility in the offspring.

Crack users suffer the effects of cocaine present in the drug and the action of other active compounds from its pyrolysis. An emergent fact is an increase in the number of pregnant crack cocaine users. Studies suggest that crack cocaine and its metabolites cross the placenta, promoting premature birth, fever, irritability, sweating, and seizures in the early months of life. In children, the effects of crack cocaine have been associated with cognitive deficits, difficulty in verbalization, aggressiveness, and depression, besides enhancing the susceptibility to epileptic seizures, including status epilepticus (SE) in adulthood. Therefore, we investigated the effect of maternal exposure to smoke crack cocaine on several behavioral parameters in the offspring during adulthood. A series of behavioral tests and intrahippocampal pilocarpine (H-PILO) microinjection at sub-convulsive and convulsive doses in a rat model demonstrated that exposure to crack cocaine during the embryonic period leads to anxiogenic-like behavior and long-term memory impairment in both genders and promotes depressive-like behavior in the female. Besides, crack cocaine offspring exposed to a sub-convulsive H-PILO dose showed higher susceptibility to SE, increased seizure frequency, and neurodegeneration, while animals that received a convulsive dose of H-PILO displayed no alteration in SE severity. Taken together, our data suggest that crack cocaine exposure during the gestational period leads to an increased predilection for anxiety and depression, long-term memory deficits, and reduction in the threshold for developing epileptic seizures associated with neuronal death, which predispose crack cocaine babies to develop neuropsychological disorders.

Modulation of Glucose Availability and Effects of Hypo- and Hyperglycemia on Status Epilepticus: What We Do Not Know Yet?

Status epilepticus (SE) can lead to serious neuronal damage and act as an initial trigger for epileptogenic processes that may lead to temporal lobe epilepsy (TLE). Besides promoting neurodegeneration, neuroinflammation, and abnormal neurogenesis, SE can generate an extensive hypometabolism in several brain areas and, consequently, reduce intracellular energy supply, such as adenosine triphosphate (ATP) molecules. Although some antiepileptic drugs show efficiency to terminate or reduce epileptic seizures, approximately 30% of TLE patients are refractory to regular antiepileptic drugs (AEDs). Modulation of glucose availability may provide a novel and robust alternative for treating seizures and neuronal damage that occurs during epileptogenesis; however, more detailed information remains unknown, especially under hypo- and hyperglycemic conditions. Here, we review several pathways of glucose metabolism activated during and after SE, as well as the effects of hypo- and hyperglycemia in the generation of self-sustained limbic seizures. Furthermore, this study suggests the control of glucose availability as a potential therapeutic tool for SE.

Role of Modulation of Hippocampal Glucose Following Pilocarpine-Induced Status Epilepticus.

Status epilepticus (SE) is defined as continuous and self-sustaining seizures, which trigger hippocampal neurodegeneration, mitochondrial dysfunction, oxidative stress, and energy failure. During SE, the neurons become overexcited, increasing energy consumption. Glucose uptake is increased via the sodium glucose cotransporter 1 (SGLT1) in the hippocampus under epileptic conditions. In addition, modulation of glucose can prevent neuronal damage caused by SE. Here, we evaluated the effect of increased glucose availability in behavior of limbic seizures, memory dysfunction, neurodegeneration process, neuronal activity, and SGLT1 expression. Vehicle (VEH, saline 0.9%, 1 µL) or glucose (GLU; 1, 2 or 3 mM, 1 µL) were administered into hippocampus of male Wistar rats (Rattus norvegicus) before or after pilocarpine to induce SE. Behavioral analysis of seizures was performed for 90 min during SE. The memory and learning processes were analyzed by the inhibitory avoidance test. After 24 h of SE, neurodegeneration process, neuronal activity, and SGLT1 expression were evaluated in hippocampal and extrahippocampal regions. Modulation of hippocampal glucose did not protect memory dysfunction followed by SE. Our results showed that the administration of glucose after pilocarpine reduced the severity of seizures, as well as the number of limbic seizures. Similarly, glucose after SE reduced cell death and neuronal activity in hippocampus, subiculum, thalamus, amygdala, and cortical areas. Finally, glucose infusion elevated the SGLT1 expression in hippocampus. Taken together our data suggest that possibly the administration of intrahippocampal glucose protects brain in the earlier stage of epileptogenic processes via an important support of SGLT1.

Maternal, fetal and neonatal consequences associated with the use of crack cocaine during the gestational period: a systematic review and meta-analysis.

OBJECTIVE: Crack cocaine consumption is one of the main public health challenges with a growing number of children intoxicated by crack cocaine during the gestational period. The primary goal is to evaluate the accumulating findings and to provide an updated perspective on this field of research. METHODS: Meta-analyses were performed using the random effects model, odds ratio (OR) for categorical variables and mean difference for continuous variables. Statistical heterogeneity was assessed using the I-squared statistic and risk of bias was assessed using the Newcastle-Ottawa Quality Assessment Scale. Ten studies met eligibility criteria and were used for data extraction. RESULTS: The crack cocaine use during pregnancy was associated with significantly higher odds of preterm delivery [odds ratio (OR), 2.22; 95% confidence interval (CI), 1.59-3.10], placental displacement (OR, 2.03; 95% CI 1.66-2.48), reduced head circumference (- 1.65 cm; 95% CI - 3.12 to - 0.19), small for gestational age (SGA) (OR, 4.00; 95% CI 1.74-9.18) and low birth weight (LBW) (OR, 2.80; 95% CI 2.39-3.27). CONCLUSION: This analysis provides clear evidence that crack cocaine contributes to adverse perinatal outcomes. The exposure of maternal or prenatal crack cocaine is pointedly linked to LBW, preterm delivery, placental displacement and smaller head circumference.