Apoptosis Of Hippocampal Neurons Research Articles

Effect of remimazolam toluene sulfonate on the cognitive function of juveniles and its mechanism of action.

Remimazolam is a new benzodiazepine. Currently, it remains unclear how repeated exposure to remimazolam affects the cognitive function of the developing brain. In the present study, the equivalent doses of the two sedatives were derived from S-shaped dose-response curves, and the ED95 of remimazolam was 45mg/kg (95% CI 37.579-79.280), and for midazolam, it was 77mg/kg (95% CI 63.751-127.21) using probability analysis. Then, we evaluated the effects of remimazolam and midazolam on cognitive function in juvenile mice (C57BL/6) through Y-maze and MWM. TUNEL staining was used to observe the apoptosis of neurons in hippocampus, western blotting was used to detect the expression changes of related proteins, and the changes of LTP were observed by recording the activity of neurons through electrical stimulation. We found that there was no significant difference in the behavior of mice in MWM. However, the short-term memory of developing mice was impaired in Y-maze after repeated exposure to remimazolam and midazolam. Furthermore, our data demonstrated that the short-term memory damage caused by remimazolam is lighter than midazolam. Concurrently, the extent of caspase-3 upregulation, the number of neuronal apoptosis in CA1 and CA3 regions, a downward trend of PSD95 and BDNF in the hippocampus, and the inhibition of LTP were highly consistent with the behavior of short-term memory impairment. These results indicate that the degree of memory impairment caused by remimazolam is milder than that caused by midazolam, making it a potential replacement for midazolam in repeated medication and long-term sedation in children.

(+)-Borneol inhibits neuroinflammation and M1 phenotype polarization of microglia in epileptogenesis through the TLR4-NFκB signaling pathway

ObjectiveTo investigate the effect of (+)-borneol on neuroinflammation and microglia phenotype polarization in epileptogenesis and its possible mechanism.MethodsBased on mouse models of status epilepticus (SE) induced by pilocarpine, and treated with 15 mg/kg (+)-borneol, western-blot was used to detect the expressions of NeuN, Iba-1, TLR4, p65 and p-p65 in the hippocampus. Immunofluorescence was used to detect the expression of apoptosis-related proteins Bax and Bcl-2. To explore the effect of (+)-borneol on microglia in vitro, we used the kainic acid-induced microglia model and the concentration of (+)-borneol was 25 μM according to CCK-8 results. The levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and interleukin-10 (IL-10) in the supernatant of each group was detected by ELISA. The nitric oxide (NO) content in the supernatant was detected by Griess method. The expressions of Iba-1 and TLR4-NFκB signaling pathway-related proteins (TLR4, p65, p-p65) were detected by Western-Blot. Immunofluorescence was used to detect microglia’s M1 and M2 phenotype polarization and the expression of Iba-1 and TLR4.Results(+)-borneol reduced hippocampal neuronal injury, apoptosis, and microglia activation by inhibiting the TLR-NFκB signaling pathway in SE mice. TLR4 agonist LPS partially reversed the neuroprotective effect of (+)-borneol. In the KA-induced microglia model, (+)-borneol inhibited microglia activation, M1 phenotype polarization, and secretion of pro-inflammatory cytokines through the TLR4-NFκB signaling pathway. LPS treatment inhibited the therapeutic effects of (+)-borneol.Conclusion(+)-borneol inhibits microglial neuroinflammation and M1 phenotype polarization through TLR4-NFκB signaling pathway and reduces neuronal damage and apoptosis in SE mice. Therefore, (+)-borneol may be a potential drug for epilepsy modification therapy.

Mitochondrial transplantation following cardiopulmonary resuscitation improves neurological function in rats by inducing M2-type MG/MΦ polarization.

Explore the effects of mitochondrial transplantation (MT) after cardiopulmonary resuscitation (CPR) on the polarization of microglia/macrophages (MG/MΦ) and neurological function. Seventy-five Sprague-Dawley rats were randomly divided into five groups: sham, normal saline (NS), vehicle, mitochondria (Mito), and non-functional mitochondria (N-Mito) group. Rats in sham group underwent surgical procedures without cardiac arrest, while the other four groups underwent cardiac arrest and CPR, and then received NS, respiration buffer, mitochondrial suspension or non-functional mitochondria, immediately after the restoration of spontaneous circulation (ROSC). The number of mitochondria in the hippocampus, the morphology and structure of mitochondria in MG/MΦ, the phenotype of MG/MΦ, and hippocampal tissue injury, neuroinflammation, and neuronal apoptosis were detected on days 1 and 3 after ROSC. Neurodeficit score (NDS) was performed on days 1, 3, 7, 15 and 30 after ROSC. Compared with other groups, the number of mitochondria in the hippocampus was increased, and the morphology and structure of mitochondria in MG/MΦ were significantly improved in the Mito group. Our results show higher expression of M2-type markers in MG/MΦ and decreased hippocampal tissue damage in the Mito group. Levels of NSE and S100β in serum, and TNF-α, IL-6 in the hippocampus were decreased, while the levels of TGF-β and IL-10 were increased in the Mito group. Apoptosis rate of neurons in the Mito group was decreased and the NDS of the Mito group was higher than the other groups. Exogenous MT can improve neurological function after CPR by promoting the polarization of MG/MΦ to M2-type cells, and this could be a potential method for brain protection after CPR.

17β-estradiol Ameliorates Postoperative Cognitive Dysfunction in Aged Mice via miR-138-5p/SIRT1/HMGB1 Pathway.

Postoperative cognitive dysfunction (POCD) is a common neurological complication in older patients and correlated with adverse outcomes.17β-estradiol treatment was reported to provide neuroprotective protection in various neurologic disorders, but whether it attenuated POCD was unknown. The purpose of this study was to explore the effects of 17β-estradiol treatment on POCD and the mechanisms. We generated a POCD model in 15-month-old mice via laparotomy, followed by subcutaneous injection of 17β-estradiol, intraperitoneal injection of EX527 (a SIRT1 inhibitor) or bilateral hippocampal injection of miR-138-5p-agomir. Morris water maze test and open field test were applied to evaluate the cognitive function. The neuronal apoptosis in hippocampus was detected using TUNEL assay. Meanwhile, the levels of IL-1β and microglia activation were measured by ELISA and immunofluorescence, respectively. Western blot was utilized to assess the expression of SIRT1 and HMGB1 protein, and gene expression of miR-138-5p was determined through qRT-PCR. Behavioral tests showed that 17β-estradiol treatment improved cognitive function in aged POCD mice. In addition, 17β-estradiol attenuated neuronal apoptosis and microglia activation as well as IL-1β expression in hippocampus. Nonetheless, injection with EX527 abolished the beneficial impacts of 17β-estradiol against POCD. Furthermore, miR-138-5p was verified to bind with SIRT1, which regulated the expression of HMGB1. After treatment with 17β-estradiol, miR-138-5p expression was reduced in hippocampus, and the neuroprotective influence of 17β-estradiol on aged POCD mice was reversed after administration of miR-138-5p-agomir. 17β-estradiol treatment exerted neuroprotection effects on POCD in aged mice, which might be relevant to alleviating neuroinflammation via miR-138-5p/SIRT1/HMGB1 pathway.

The involvement of lidocaine in amyloid-β1-42-dependent mitochondrial dysfunction and apoptosis in hippocampal neurons via nerve growth factor-protein kinase B pathway.

This project is conceived to reveal the role of lidocaine in the process of Alzheimer's disease (AD) and its possible downstream targets. After the employment of AD cell model in mice hippocampal neuronal HT-22 cells in the presence of amyloid-β1-42 (Aβ1-42), Cell Counting Kit-8 method investigated cell viability. Oxidative damage was assayed based on a dichloro-dihydro-fluorescein diacetate fluorescent probe and commercially available kits. The 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolocarbocyanine iodide fluorescent probe estimated mitochondrial function. Terminal-deoxynucleotidyl transferase mediated nick end labeling, western blotting, and immunofluorescence appraised the apoptotic level. Western blot also ascertained the alternations of nerve growth factors (NGF)-protein kinase B (Akt) pathway-related proteins. Aβ1-42 concentration dependently triggered the viability loss, oxidative damage, and apoptosis in HT-22 cells. Lidocaine promoted the viability and reduced the mitochondrial impairment and mitochondria-dependent apoptosis in Aβ1-42-treated HT-22 cells in a concentration-dependent manner. Besides, lidocaine activated the NGF-Akt pathway and NGF absence blocked NGF-Akt pathway, aggravated mitochondrial dysfunction as well as mitochondria-dependent apoptosis in lidocaine-administrated HT-22 cells in response to Aβ1-42. Altogether, these observations concluded that lidocaine might stimulate NGF-Akt pathway to confer protection against mitochondrial impairment and apoptosis in Aβ1-42-mediated cellular model of AD.

Yeast Extract Peptides Alleviate Depression in Chronic Restraint Stress Rats by Alleviating Hippocampal Neuronal Apoptosis and Dysbiosis of the Gut Microbiota.

Depression as a global neurological disorder, and hippocampal neuronal apoptosis and disorders of the gut microbiota are closely related to it. This study aims to expose the ameliorative effect of enzyme peptides (AP) from brewer's yeast on depressive behavior caused by chronic restraint stress (CRS) in rats. After 4 weeks of AP intervention, a significant alleviation of depressive behavior in the sucrose preference test (SPT), forced swim test (FST), and light-dark test (LDT) is observed in depressed rats. AP ameliorates neuronal damage with increased the expression of the key CREB/BDNF/TrkB/Akt signaling pathway, which increases the levels of the monoamine neurotransmitters 5-hydroxytryptamine (5-HT) and norepinephrine (NE) in the hippocampus, buffering hyperactivity of the hypothalamo-pituitary-adrenal axis (HPA), and decreasing the serum cortisol (CORT) and adrenocorticotropic hormone (ACTH) levels in rats. In addition, AP modulates the disruption of the rat gut microbiota by chronic restraint stress (CRS), and the changes in the abundance of Lactobacillus animalis and Lactobacillus johnsonii are probably the key for AP performing antidepressant benefits. A strong correlation is found between gut microbiota and biochemical markers of depression. AP, as a natural and safe active substance, has a positive effect in the treatment of depression.

Low-frequency rTMS Plays a Neuroprotective role in Pilocarpine-induced Status Epilepticus Rat Models Through the AMPAR GluA1-STIM-Ca2+ Pathway.

Low-frequency repetitive transcranial magnetic stimulation (rTMS) refers to the stimulation of the brain using repetitive magnetic field pulses at a low frequency (≤ 1Hz) to reduce seizures. Currently, the mechanism is not well understood.Male Sprague-Dawley rats underwent pilocarpine-induced status epilepticus (SE) and were then stimulated with low-frequency rTMS. An epilepsy cell model was then established by incubating rat hippocampal neurons with Mg2+-free extracellular fluids. The effects of the low-frequency rTMS on epileptogenesis and hippocampal neuron injury were evaluated using a video electroencephalogram (vEEG) and Nissl staining, and the expression of AMPAR GluA1 and STIM in the hippocampus and hippocampal neurons was assessed using western blot and immunofluorescence. Additionally, the intracellular Ca2+ concentration and reactive oxygen species (ROS) were measured using flow cytometry.Low-frequency rTMS attenuated spontaneous recurrent seizures in rats with epilepsy, with the SE group exhibiting a higher incidence (100%) and frequency (3.00 ± 0.18 times/day) than the SE + 0.3 (50% incidence, 0.06 ± 0.03 times/day), SE + 0.5 (0.20 ± 0.02 times/day) and SE + 1Hz (1.02 ± 0.05 times/day) groups. Additionally, rTMS reduced the damage and apoptosis of hippocampal pyramidal neurons, increasing their numbers in the CA1 and CA3 regions. Furthermore, AMPAR GluA1 and STIM expression were upregulated in the hippocampus when using rTMS, reversing the downregulation caused by seizures. Immunofluorescence verified the increased fluorescence intensity of AMPAR GluA1 and STIM. Moreover, rTMS inhibited Ca2+ overload and ROS in epileptic neuron models.Low-frequency rTMS may exert neuroprotective effects through the AMPAR GluA1-STIM-Ca2+ pathway.

Glycyrrhizic Acid Inhibits Hippocampal Neuron Apoptosis by Activating the PI3K/ AKT Signaling Pathway.

Glycyrrhizic acid (GA), one of the main active substances in Glycyrrhiza, has anti-inflammatory, anti-viral, and neuroprotective effects. GA can significantly reduce cerebral infarction size in middle cerebral artery occlusion (MCAO) rats and suppress inflammatory responses. However, the underlying mechanism by which GA protects the neuronal system remains poorly understood. Cell proliferation and viability were tested using CCK-8 and Edu assays. The effects of GA on apoptosis were detected using flow cytometry and Tunel assays. Western blotting was performed to assess protein expression. Behavioral experiments were conducted using the Morris water maze and rotation tests. Infarct size was observed using TTC staining. We report that GA protects neurons by inhibiting apoptosis, mainly through the PI3K/AKT pathway in oxygen-glucose deprivation/reoxygenation (OGD/R) and MCAO rat models. GA increases the viability and proliferation of oxygen- and glucose-deprived hippocampal neurons. Hippocampal neuron apoptosis decreased after GA treatment in vitro and in vivo. Furthermore, we determined that GA treatment increased the active state of PI3K and its downstream protein p-AKT, whereas when using a specific inhibitor of PI3K, Y294002, the levels of p-PI3K and p-AKT decreased. Finally, we showed that GA treatment improved spatial memory and motor coordination in MCAO rats, while TTC staining showed that GA decreased cerebral infarct size in MCAO rats. We reveal that GA protects hippocampal neurons by inhibiting their apoptosis, mainly through the PI3K/AKT signaling pathway.

HINT1 promotes neuronal apoptosis and triggers schizophrenia-like behavior in rats

This study aims to investigate the mechanism by which Histidine triad nucleotide-binding protein 1 (HINT1) promotes hippocampal neuronal apoptosis, triggering schizophrenia (SZ)-like behavior in rats. By establishing a rat SZ-like model, we assessed learning, memory, emotional response, and cognitive function through the Morris Water Maze, auditory startle response, and open field tests. HINT1 expression in the hippocampus was analyzed via RT-PCR and Western blot. We also created a HINT1 overexpression model in hippocampal neuronal cells to analyze its effects on cell proliferation and apoptosis. This analysis was conducted using the CCK-8 assay and flow cytometry, along with the quantification of apoptosis-related proteins and neurotrophic factors. Our findings indicated that the SZ-like model rats exhibited diminished learning and memory abilities, altered emotional reactions, and impaired cognitive functions, alongside a notable increase in HINT1 mRNA and protein levels. HINT1 overexpression was observed to inhibit hippocampal neuronal cell proliferation and promote apoptosis, with an increase in the expression of pro-apoptotic proteins and a decrease in neurotrophic factors. These results suggest HINT1's role in the onset and development of SZ-like behavior through its upregulation and induction of apoptosis in hippocampal neuronal cells, underlining its potential as a therapeutic target.

Remimazolam ameliorates postoperative cognitive dysfunction after deep hypothermic circulatory arrest through HMGB1-TLR4-NF-κB pathway

BackgroundPostoperative cognitive dysfunction (POCD) is a complication of deep hypothermic circulatory arrest (DHCA). Various amounts of neurologic dysfunctions have been shown after DHCA, which has often been attributed to systemic inflammatory response syndrome and cerebral ischemia/reperfusion injury. Remimazolam is one of the commonly used anesthetic drugs with protective actions against inflammatory diseases, such as sepsis and cerebral ischemia/reperfusion injury. Here, we determined the protective effect and potential mechanism of action of remimazolam against neuronal damage after DHCA. MethodsA rat model of DHCA was established, and a gradient dosage of remimazolam was administered during cardiopulmonary bypass (CPB). The cognitive function of rats was evaluated by Morris water maze. Hematoxylin and eosin and TUNEL staining were performed to assess hippocampus tissue injury and neuronal apoptosis. Inflammatory cytokines concentration were analyzed by enzyme-linked immunosorbent assay. The protein expression was analyzed using automated electrophoresis western analysis and immunohistochemical analysis. ResultsThe appropriate dosage of remimazolam reduced histologic injury, neuronal apoptosis, microglia activation, and secondary inflammatory cascades, as well as the downregulation of the expression of the HMGB1-TLR4-NF-κB pathway after DHCA, improved the memory and learning abilities in DHCA rats. Further, administration of a TLR4 antagonist TAK-242 had a similar effect to remimazolam, while the TLR4 agonist LPS attenuated the effect of remimazolam. ConclusionsRemimazolam could ameliorate POCD after DHCA through the HMGB1-TLR4-NF-κB signaling pathway.

Impaired learning and memory in male mice induced by sodium arsenite was associated with MMP-2/MMP-9-mediated blood-brain barrier disruption and neuronal apoptosis

Arsenic is a widespread environmental contaminant known to accumulate in the brain, leading to cognitive impairment. However, the exact mechanisms by which arsenic causes cognitive deficits remain unclear. The present study aims to discover whether the destruction of the blood-brain barrier (BBB) mediated by matrix metalloproteinases 2 and matrix metalloproteinases 9 (MMP-2 and MMP-9) and subsequent neuronal apoptosis are involved in arsenic-induced cognitive impairment. Ninety male mice were given 0, 25, and 50 mg/L NaAsO2 in drinking water and 30 mg/kg doxycycline hyclate (DOX, an inhibitor of MMPs) gavage for 12 weeks to observe the alterations in learning and memory of mice, the morphology of hippocampal neurons, as well as the BBB permeability and ultrastructure, the localization and expression of tight junction proteins, MMP-2, and MMP-9. Our findings indicated that arsenic exposure induced learning and memory impairment in mice, accompanied by neuronal loss and apoptosis. Furthermore, arsenic exposure increased hematogenous IgG leakage into the brain, disrupted the tight junctions, reduced the expression of Claudin5, Occludin, and ZO1 in the endothelial cells, and increased the expression of MMP-2 and MMP-9 in the endothelial cells and astrocytes. Finally, DOX intervention preserved BBB integrity, alleviated hippocampal neuronal apoptosis, and improved cognitive impairment in mice caused by arsenic exposure. Our research demonstrates that cognitive disfunction in mice induced by arsenic exposure is associated with MMP-2 and MMP-9-mediated BBB destruction and neuronal apoptosis. The current investigation provides new insights into mechanisms of arsenic neurotoxicity and suggests that MMP-2 and MMP-9 may serve as potential therapeutic targets for treating arsenic-induced cognitive dysfunction in the future.

Deciphering the Protective Role of HIF-1α Downregulation on HIBD through the MALAT1/miR-140-5p/TGFBR1/NF-κB Signaling Pathway.

Hypoxic-ischemic brain damage (HIBD) in neonates is a substantial cause of mortality and neurodevelopmental impairment, with the exact molecular mechanisms still being elucidated. The involvement of HIF-1α, MALAT1, miR-140-5p, TGFBR1, and the NF-κB signaling pathway in such injury cascades is of increasing research interest due to their pivotal roles in cellular and pathological processes. This study aimed to explore how HIF-1α regulates the MALAT1/miR-140-5p/TGFBR1/NF-κB signaling axis to participate in the molecular mechanisms of HIBD in neonatal rats. Utilizing bioinformatic analyses and a suite of experimental approaches, the study delineated interactions and regulatory relationships among the molecules. Knockdown of HIF-1α was shown to mitigate brain tissue damage in a neonatal HIBD rat model through the MALAT1/miR-140-5p/TGFBR1/NF-κB signaling axis, revealing a protective effect achieved by inhibiting hippocampal neuron apoptosis and potentially guiding the way toward therapeutic interventions in HIBD. This study implicates the HIF-1α mediated regulation of the MALAT1/miR-140-5p/TGFBR1/NF-κB signaling axis in the pathological development of HIBD, offering insights into novel potential interventional strategies.

Berberine Alleviates Sevoflurane Anesthesia-Induced Cognitive Dysfunction in Neonatal Mice via Regulating CREB1.

Sevoflurane has been shown to stimulate neurotoxicity and lead to cognitive impairment. Berberine is known for its role in regulating nervous system diseases, including cognitive dysfunction. This study aimed to investigate the effects of berberine on cognitive dysfunction induced by sevoflurane anesthesia and its potential mechanisms. In the in vivo study, neonatal mice were subjected to sevoflurane anesthesia to induce cognitive dysfunction. The cognitive function of the neonatal mice was evaluated using the Morris water maze test, open field test, and tail suspension test. Enzyme-linked immunosorbent assay (ELISA) was utilized to assess the levels of inflammatory factors. Immunohistochemistry (IHC) was conducted to detect ionized calcium-binding adaptor molecule 1 (IBA-1)-positive cells and cleaved caspase-3-positive cells in the hippocampus of the neonatal mice. Western blotting was used to measure the levels of cyclic adenosine monophosphate (cAMP) response element-binding protein 1 (CREB1) in hippocampal tissues and neurons. Hippocampal neurons were isolated from the hippocampus of neonatal mice. These neurons were treated with berberine or subjected to cell transfection. The cell counting kit-8 (CCK-8) assay and terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assay were conducted to measure cell viability and apoptosis of hippocampal neurons in vitro. Berberine significantly attenuated sevoflurane-induced cognitive impairment and inflammation in neonatal mice (p < 0.05 or p < 0.01). Additionally, berberine reduced sevoflurane-triggered neuronal apoptosis in the hippocampus of neonatal mice (p < 0.01). Sevoflurane markedly decreased CREB1 expression in the hippocampus of neonatal mice (p < 0.01), which was elevated by berberine treatment (p < 0.01). Mechanistically, sevoflurane significantly suppressed cell viability and promoted cell apoptosis of hippocampal neurons (p < 0.0001 or p < 0.01), which were mitigated by berberine (p < 0.05, p < 0.01, or p < 0.001). Furthermore, berberine significantly elevated CREB1 expression in sevoflurane-treated hippocampal neurons (p < 0.01). The beneficial effects of berberine on cell viability and apoptosis in sevoflurane-treated hippocampal neurons were blocked by CREB1 depletion (p < 0.001). Our results demonstrated that CREB1 was significantly decreased in the hippocampus of sevoflurane-treated neonatal mice in vivo and in sevoflurane-treated hippocampal neurons in vitro. This decrease was mitigated by berberine treatment. Moreover, berberine improved sevoflurane anesthesia-induced cognitive impairment in neonatal mice by attenuating neuronal inflammation and apoptosis in vivo. The inhibitory effects of berberine on sevoflurane-induced cell apoptosis were reversed by CREB1 downregulation. These findings indicate that berberine protects against sevoflurane anesthesia-induced cognitive impairment by reducing apoptosis of hippocampal neurons, partially through increasing CREB1 expression.

Genetic patterning in hippocampus of rat undergoing impaired spatial memory induced by long-term heat stress

The organism's normal physiological function is greatly impacted in a febrile environment, leading to the manifestation of pathological conditions including elevated body temperature, dehydration, gastric bleeding, and spermatogenic dysfunction. Numerous lines of evidence indicate that heat stress significantly impacts the brain's structure and function. Previous studies have demonstrated that both animals and humans experience cognitive impairment as a result of exposure to high temperatures. However, there is a lack of research on the effects of prolonged exposure to high-temperature environments on learning and memory function, as well as the underlying molecular regulatory mechanisms. In this study, we examined the impact of long-term heat stress exposure on spatial memory function in rats and conducted transcriptome sequencing analysis of rat hippocampal tissues to identify the crucial molecular targets affected by prolonged heat stress exposure. It was found that the long-term heat stress impaired rats' spatial memory function due to the pathological damages and apoptosis of hippocampal neurons at the CA3 region, which is accompanied with the decrease of growth hormone level in peripheral blood. RNA sequencing analysis revealed the signaling pathways related to positive regulation of external stimulation response and innate immune response were dramatically affected by heat stress. Among the verified differentially expressed genes, the knockdown of Arhgap36 in neuronal cell line HT22 significantly enhances the cell apoptosis, suggesting the impaired spatial memory induced by long-term heat stress may at least partially be mediated by the dysregulation of Arhgap36 in hippocampal neurons. The uncovered relationship between molecular changes in the hippocampus and behavioral alterations induced by long-term heat stress may offer valuable insights for the development of therapeutic targets and protective drugs to enhance memory function in heat-exposed individuals.

The impact of dexmedetomidine on ketamine-induced neurotoxicity and cognitive impairment in young mice.

The potential neuroprotective effects of dexmedetomidine against ketamine-induced neurotoxicity remain inconclusive. This study aims to investigate the influence of dexmedetomidine on ketamine-induced neuronal apoptosis and neurodevelopmental toxicity. In vitro experiments employed concentrations of 0.1uM for dexmedetomidine and 50 uM for ketamine individually as well as their combination. Changes in apoptotic proteins and dendritic development in neurons were assessed after a 6-h exposure to the drugs with evaluations conducted 24hs' post-treatment. In vivo experiments entailed intraperitoneal administration starting from postnatal Day 7 (P7) continuously for 3days (P7-P9) using dosages of 100 mg/kg for ketamine and 1mg/kg for dexmedetomidine alone or combined. Learning, memory and motor coordination abilities were evaluated via rotary rod tests and shuttle box experiments at P30 and P60, respectively. Dexmedetomidine effectively mitigated ketamine-induced apoptosis in hippocampal neurons but did not alleviate associated dendritic developmental abnormalities. Although causing reduced motor coordination in mice, no improvement was observed with regard to this effect or reaction speed when treated with dexmedetomidine alongside ketamine. This study demonstrates that while dexmedetomidine can mitigate ketamine-induced neuronal apoptosis, it has limited impact on its associated neurodevelopmental toxicities.

Diosmin ameliorates inflammation, apoptosis and activates PI3K/AKT pathway in Alzheimer's disease rats.

Alzheimer's disease (AD), a prevalent cognitive disorder among the elderly, is frequently linked to the abnormal accumulation of myloid-β (Aβ), which is mainly as a result of neuronal death and inflammation. Diosmin, a flavonoid, is considered a potential drug for the treatment of AD. Our study aimed to uncover the molecular mechanism of diosmin in AD therapy. Here, rats were randomly divided into three groups: control, Aβ25-35, and Aβ25-35 + diosmin groups. AD model rats were induced by Aβ25-35 intraventricular injection, meanwhile 50mg/kg diosmin was orally administered for 6-week intervention. Morris water maze test assessed learning and memory abilities. Hippocampal neuronal damage was determined by HE, Nissl, and TUNEL staining. These assays indicate that diosmin improves cognitive dysfunction and reduces hippocampal neuronal loss and apoptosis. Western blot showed that diosmin reduced Bax (1.21 ± 0.12) and cleaved caspase-3 (1.27 ± 0.12) expression, and increased Bcl-2 (0.70 ± 0.06), p-PI3K (0.71 ± 0.08), and p-AKT (0.96 ± 0.10) in the hippocampus. ELISA indicated diosmin reduces IL-1β, IL-6, and TNF-α levels, suggesting anti-inflammation effect. These results suggest that diosmin inhibits neuronal apoptosis and neuroinflammatory responses to improve cognitive dysfunction in AD rats, possibly related to upregulation of the PI3K/AKT pathway, providing a scientific basis for its use in AD treatment.

Dingxian pill alleviates hippocampal neuronal apoptosis in epileptic mice through TNF-α/TNFR1 signaling pathway inhibition

Ethnopharmacological relevanceDingxian Pill (DXP), a famous traditional Chinese medicine prescription, and has been widely proven to have positive therapeutic effects on “Xianzheng” (the name of epilepsy in ancient China). However, the anti-epileptic molecular mechanisms of DXP are not yet fully understood and remain to be further investigated. Aim of the studyTo elucidate the molecular mechanism of DXP's improvement in epileptic neuronal loss, damage and apoptosis by regulating TNF-α/TNFR1 signaling pathway. Materials and methodsSixty Kunming mice were randomly divided in 6 groups: control group (equal volume of normal saline), model group (180 mg kg−1 pilocarpine hydrochloride – used to establish the epilepsy animal model), carbamazepine group (30 mg kg−1), and low, medium, and high-dose Dingxian Pill groups (4.08, 8.16, and 16.32 g kg−1, respectively – oral administration once daily for 2 weeks). Successful establishment of the epileptic mouse model was monitored with electroencephalography. Pathological changes in hippocampal tissue were analyzed with hematoxylin-eosin staining. Hippocampal neuronal apoptosis was analyzed with TUNEL staining. TNF-α, TNFR1, TRADD, FADD, and caspase-8 mRNA and protein expression levels in hippocampal tissue were analyzed with real-time quantitative polymerase chain reaction, immunohistochemistry, and Western blot, respectively. Cleaved caspase-8 protein levels in hippocampal tissue were measured with immunohistochemistry and Western blot. ResultsCompared to control, the model group showed an increase in continuous epileptic discharge waves on EEG, a damaged hippocampal neuron morphological structure, increased hippocampal neuronal apoptosis, and significantly increased TNF-α, TNFR1, TRADD, FADD, and caspase-8 mRNA and protein levels, and increased caspase-8 cleavage (P < 0.05). Compared to the model group, the carbamazepine group as well as the low-, medium-, and high-dose Dingxian Pill groups showed decreased epileptic discharges on EEG, an obvious hippocampal neuron morphological structure restoration, varying degrees of attenuated hippocampal neuronal apoptosis, and significantly decreased TNF-α, TNFR1, TRADD, FADD, and caspase-8 mRNA and protein levels as well as decreased caspase-8 cleavage (P < 0.05). ConclusionsDingxian Pill exerts an anti-epileptic effect through inhibition of TNF-α/TNFR1 signaling pathway-mediated apoptosis in hippocampal neurons.

Hippocampal Crhr1 conditional gene knockout ameliorated the depression-like behavior and pathological damage in male offspring mice caused by chronic stress during pregnancy

Numerous studies have demonstrated that chronic stress during pregnancy (CSDP) can induce depression and hippocampal damage in offspring. It has also been observed that high levels of corticotropin-releasing hormone (CRH) can damage hippocampal neurons, and intraperitoneal injection of a corticotropin releasing hormone receptor 1 (CRHR1) antagonist decreases depression-like behavior and hippocampal neuronal damage in a mouse depression model. However, whether CSDP causes hippocampal damage and depression in offspring through the interaction of CRH and hippocampal CRHR1 remains unknown and warrants further investigation. Therefore, hippocampal Crhr1 conditional gene knockout mice and C57/BL6J mice were used to study these questions. Depression-related indexs in male offspring mice were examined using the forced swim test (FST), sucrose preference test (SPT), tail suspension test (TST) and open field test (OFT). Serum CRH levels were measured by enzyme-linked immunosorbent assay (ELISA). Golgi-Cox staining was used to examine the morphological changes of hippocampal neuronal dendrites. Neuronal apoptosis in the hippocampal CA3 regions was detected by terminal deoxynucleotidy transferase dUTP nick end labeling (TUNEL) staining. The levels of mammalian target of rapamycin (mTOR), phosphorylated mTOR (p-mTOR) and protein kinase B (AKT) proteins were measured by Western blot analysis. This study showed that CSDP induces depression-like behavior, hippocampal neuronal dendrite damage and apoptosis in male offspring mice. Conditional gene knockout of hippocampal Crhr1 in mice reduced CSDP-induced depression-like behavior, hippocampal neuronal dendrite damage and apoptosis in male offspring, and counteracted the CSDP-induced decreased expression of p-Akt and mTOR activity in male offspring hippocampus. These findings demonstrated that CSDP might inhibit the Akt/mTOR pathway by increasing the levels of CRH, leading to increased CRH-mediated activation of hippocampal CRHR1, thereby inducing synaptic impairment and apoptosis in hippocampal neurons, which in turn leads to depression-like behavior in offspring.

Cold inducible RNA binding protein-regulated mitochondria associated endoplasmic reticulum membranes-mediated Ca2+ transport play a critical role in hypothermia cerebral resuscitation

Cardiac arrest is a global health issue causing more deaths than many other diseases. Hypothermia therapy is commonly used to treat secondary brain injury resulting from cardiac arrest. Previous studies have shown that CIRP is induced in specific brain regions during hypothermia and inhibits mitochondrial apoptotic factors. However, the specific mechanisms by which hypothermia-induced CIRP exerts its anti-apoptotic effect are still unknown. This study aims to investigate the role of Cold-inducible RNA-binding protein (CIRP) in mitochondrial-associated endoplasmic reticulum membrane (MAM)-mediated Ca2+ transport during hypothermic brain resuscitation.We constructed a rat model of cardiac arrest and resuscitation and hippocampal neuron oxygen-glucose deprivation/reoxygenation model. We utilized shRNA transfection to interfere the expression of CIRP and observe the effect of CIRP on the structure and function of MAM.Hypothermia induced CIRP can reduce the apoptosis of hippocampal neurons, and improve the survival rate of rats. Hypothermia induced CIRP can reduce the expressions of calcium transporters IP3R and VDAC1 in MAM, reduce the concentration of calcium in mitochondria, decrease the expression of ROS, and stabilize the mitochondrial membrane potential. Immunofluorescence and immunocoprecipitation showed that CIRP could directly interact with IP3R-VDAC1 complex, thereby changing the structure of MAM, inhibiting calcium transportation and improving mitochondrial function in vivo and vitro.Both in vivo and in vitro experiments have confirmed that hypothermia induced CIRP can act on the calcium channel IP3R-VDAC1 in MAM, reduce the calcium overload in mitochondria, improve the energy metabolism of mitochondria, and thus play a role in neuron resuscitation. This study contributes to understanding hypothermia therapy and identifies potential targets for brain injury treatment.

The effect of miR‑155‑5p on long‑term memory of sleep‑deprived mice through the BDNF/NF‑κB pathway.

Sleep deprivation (SD) is a prevalent sleep issue in modern society that significantly impairs neurological function and quality of life in affected individuals. This study seeks to investigate the involvement of the miR‑155‑5p/BDNF axis in SD mice, aiming to establish a theoretical foundation for potential treatment strategies. Male C57BL/6 mice were utilized in the construction of a SD model using the flower pot technique. HT22 cells were selected for cellular experiments. The Morris water maze was employed to assess the learning and memory capabilities of the mice. HE staining was utilized to observe pathological changes in hippocampal tissue. Levels of IL‑1β, IL‑6, and TNF‑α were analyzed using ELISA. The expression level of miR‑155‑5p was quantified via RT‑qPCR. The binding between miR‑155‑5p and brain‑derived neurotrophic factor (BDNF) was confirmed through a dual‑luciferase reporter assay. Apoptosis of hippocampal neurons was assessed using TUNEL. Western blot analysis was conducted to evaluate the expression levels of BDNF, p65, and p‑p65. The Morris water maze test revealed that the mice exhibited prolonged escape latency, decreased swimming velocity, and reduced time spent in the target platform quadrant, which are indicative of a successful construction of the SD model. The observed cognitive deficits in the mice were associated with SD‑induced damage to the hippocampal tissue, leading to increased levels of miR‑155‑5p and decreased levels of BDNF. miR‑155‑5p was found to directly bind to BDNF, thereby suppressing its mRNA and protein expression. The upregulation of BDNF effectively mitigated hippocampal damage by attenuating cell apoptosis and reducing inflammation levels in SD mice. Additionally, the BDNF/NF‑κB pathway was found to be suppressed in SD mice through the downregulation of miR‑155‑5p. Therefore, the silencing of miR‑155‑5p inhibited the activation of the NF‑κB pathway by upregulating BDNF, which improved long‑term memory and reduced neuronal damage in SD mice.