Structural and Pharmacological Network Analysis of miRNAs Involved in Acute Ischemic Stroke: A Systematic Review

Acute ischemic stroke (AIS) is among the main causes of mortality worldwide. A rapid and opportune diagnosis is crucial to improve a patient’s outcomes; despite the current advanced image technologies for diagnosis, their implementation is challenging. MicroRNAs have been recognized as useful as biomarkers since they are specific and stable for characterization of AIS. However, there is still a lack of consensus over the primary miRNAs implicated in AIS. Here, we performed a systematic review of the literature covering from 2015–2021 regarding miRNAs expression during AIS and built structural networks to analyze and identify the most common miRNAs expressed during AIS and shared pathways, genes, and compounds that seem to influence their expression. We identified two sets of miRNAs: on one side, a set that was independent of geographical location and tissue (miR-124, miR-107, miR-221, miR-223, miR-140, miR-151a, miR-181a, miR-320b, and miR-484); and on the other side, a set that was connected (hubs) in biological networks (miR-27b-3p, miR-26b-5p, miR-124-3p, miR-570-3p, miR-19a-3p, miR-101-3p and miR-25-3p), which altered FOXO3, FOXO4, and EP300 genes. Interestingly, such genes are involved in cell death, FOXO-mediated transcription, and brain-derived neurotrophic factor signaling pathways. Finally, our pharmacological network analysis depicted a set of toxicants and drugs related to AIS for the first time

Insomnia Impairs Both the Pro-BDNF and the BDNF Levels Similarly to Older Adults with Cognitive Decline: An Exploratory Study

Sleep disorders, including insomnia, are common during aging, and these conditions have been associated with cognitive decline in older adults. Moreover, during the aging process, neurotransmitters, neurohormones, and neurotrophins decrease significantly, leading to the impairment of cognitive functions. In this sense, BDNF, the most abundant neurotrophic factor in the human brain, has been suggested as a potential target for the prevention and improvement of cognitive decline during aging; however, the current evidence demonstrates that the exogenous administration of BDNF does not improve cognitive function. Hence, in the present study, we quantified pro-BDNF (inactive) and BDNF (active) concentrations in serum samples derived from older individuals with insomnia and/or cognitive decline. We used linear regression to analyze whether clinical or sociodemographic variables impacted the levels of BNDF concentration. We observed that insomnia, rather than cognitive decline, is significantly associated with BDNF concentration, and these effects are independent of other variables. To our knowledge, this is the first study that points to the impact of insomnia on improving the levels of BDNF during aging and suggests that opportune treatment of insomnia may be more beneficial to prevent cognitive decline during aging

Data-Driven Approaches Used for Compound Library Design for the Treatment of Parkinson’s Disease

Parkinson’s disease (PD) is the second most common neurodegenerative disease in older individuals worldwide. Pharmacological treatment for such a disease consists of drugs such as monoamine oxidase B (MAO-B) inhibitors to increase dopamine concentration in the brain. However, such drugs have adverse reactions that limit their use for extended periods; thus, the design of less toxic and more efficient compounds may be explored. In this context, cheminformatics and computational chemistry have recently contributed to developing new drugs and the search for new therapeutic targets. Therefore, through a data-driven approach, we used cheminformatic tools to find and optimize novel compounds with pharmacological activity against MAO-B for treating PD. First, we retrieved from the literature 3316 original articles published between 2015–2021 that experimentally tested 215 natural compounds against PD. From such compounds, we built a pharmacological network that showed rosmarinic acid, chrysin, naringenin, and cordycepin as the most connected nodes of the network. From such compounds, we performed fingerprinting analysis and developed evolutionary libraries to obtain novel derived structures. We filtered these compounds through a docking test against MAO-B and obtained five derived compounds with higher affinity and lead likeness potential. Then we evaluated its antioxidant and pharmacokinetic potential through a docking analysis (NADPH oxidase and CYP450) and physiologically-based pharmacokinetic (PBPK modeling). Interestingly, only one compound showed dual activity (antioxidant and MAO-B inhibitors) and pharmacokinetic potential to be considered a possible candidate for PD treatment and further experimental analysis

Effect of PRL on [Ca²⁺]i in a cultured of hippocampal rat neurons.

<p>(<b>A</b>) Control, neurons stimulated with PRL (10 ng/mL for 6 min). (<b>B</b>) Neurons stimulated with Glu (100 μM for 5 min). (<b>C</b>) Neurons pretreated with PRL (10 ng/mL for 72 h) and then exposed to Glu (100 μM for 6 min). Each recording of [Ca2+]i represents an independent experiment. (<b>D</b>) Bars represent the mean ± SD [Ca²⁺]i from 4–9 independent experiments. Data were analyzed by one-way ANOVA followed by Tukey´s post hoc test.** <i>p</i><0.01 versus Glu.</p

Neuroprotective effect of PRL against glutamate-induced excitotoxicity. Cell viability was assessed by the Syto-13 and propidium iodide (PI) assay and mitochondrial activity was assessed by the MTT reduction assay.

<p>Cell cultures were treated with PRL or Glu alone, or both PRL (10 ng/mL for 72 h) and Glu (100 μM for 24 h). (<b>A</b>) Representative images from neurons stained with Syto-13 (green) and PI (red) in cultures exposed to the different treatments: <b><i>a-c</i>,</b> Vehicle (saline solution). <b><i>d-f</i>,</b> PRL (10 ng/mL). <b><i>g-i</i>,</b> PRL/Glu (10ng/mL and100 μM respectively), <b><i>j-l</i>,</b> Glu (100 μM). White arrows indicate red condensed nuclei indicative of dead cells. (<b>B</b>) Values are the mean ± SD (n = 4 independent experiments). (<b>C</b>) Mitochondrial activity was assessed by MTT reduction. (<b>D</b>) LDH activity in medium culture expressed by the Δ Abs at 340nm. Data were analyzed by one-way ANOVA followed by a Tukey´s post hoc test *<i>p</i><0.05 vs Glu, **<i>p</i><0.001 vs Glu. Scale bar = 100 μm.</p

PRL prevented procaspase-3 cleavage in hippocampal neurons exposed to Glu.

<p>(<b>A</b>) Results from Western blot and densitometry analyses are expressed as the relative ratio of cleaved caspase-3/GAPDH. Bars represent the mean ± SD from 4 independent experiments. Data were analyzed by one-way ANOVA followed by Tukey´s post hoc test. ** <i>p</i><0.01 <i>vs</i> Glu. Control (Saline Solution; Ctrl), PRL (10 ng/mL), PRL/Glu (10 ng/mL and 100 μM, respectively), Glu (100 μM), rat uterus in estrous (ERU).</p

Prolactin-induced neuroprotection against glutamate excitotoxicity is mediated by the reduction of [Ca²⁺]i overload and NF-κB activation

<div><p>Prolactin (PRL) is a peptidic hormone that displays pleiotropic functions in the organism including different actions in the brain. PRL exerts a neuroprotective effect against excitotoxicity produced by glutamate (Glu) or kainic acid in both <i>in vitro</i> and <i>in vivo</i> models. It is well known that Glu excitotoxicity causes cell death through apoptotic or necrotic pathways due to intracellular calcium ([Ca²⁺] i) overload. Therefore, the aim of the present study was to assess the molecular mechanisms by which PRL maintains cellular viability of primary cultures of rat hippocampal neurons exposed to Glu excitotoxicity. We determined cell viability by monitoring mitochondrial activity and using fluorescent markers for viable and dead cells. The intracellular calcium level was determined by a fluorometric assay and proteins involved in the apoptotic pathway were determined by immunoblot. Our results demonstrated that PRL afforded neuroprotection against Glu excitotoxicity, as evidenced by a decrease in propidium iodide staining and by the decrease of the LDH activity. In addition, the MTT assay shows that PRL maintains normal mitochondrial activity even in neurons exposed to Glu. Furthermore, the Glu-induced intracellular [Ca²⁺]i overload was attenuated by PRL. These data correlate with the reduction found in the level of active caspase-3 and the pro-apoptotic ratio (Bax/Bcl-2). Concomitantly, PRL elicited the nuclear translocation of the transcriptional factor NF-κB, which was detected by immunofluorescence and confocal microscopy. To our knowledge, this is the first report demonstrating that PRL prevents Glu excitotoxicity by a mechanism involving the restoration of the intracellular calcium homeostasis and mitochondrial activity, as well as an anti-apoptotic action possibly mediated by the activity of NF-κB. Overall, the current results suggest that PRL could be of potential therapeutic advantage in the treatment of neurodegenerative diseases.</p></div

PRL induced NF-κB activation in hippocampal neurons. Nuclear translocation of NF-κB was assessed by immunochemistry.

<p>Cell cultures were exposed to PRL (10 ng/mL for 72 h) and Glu (100 μM for 24 h), or were treated with PRL or Glu alone. Representative photomicrographs from primary cultures of rat hippocampal neurons: <b><i>a-d</i>,</b> Vehicle. <b><i>e-h</i>,</b> PRL (10 ng/mL). <b><i>i-l</i>,</b> PRL/Glu (10ng/mL and 100 μM respectively), <b><i>m-p</i>,</b> Glu (100 μM). Cytoskeleton was stained green with Phalloidin 488: nuclei were stained blue with Hoechst and in NF-κB protein was labeled in red. White arrows indicate nuclear translocation of NF-κB. Scale bar = 24.08 μm.</p

Proposed molecular mechanisms involved in the PRL-mediated neuroprotective effect against Glu-induce excitotoxicity in primary cultures of rat hippocampal neurons, which includes.

<p><b>a)</b> Regulation of [Ca²⁺]i homeostasis, <b>b)</b> NF-κB activation and the <b>c)</b> Concomitant overexpression of anti-apoptotic proteins. Question marks and dotted lines indicate hypothetical relationships.</p