Histopathological Changes In Brain Research Articles

Xinglou Chengqi Decoction Protects against Cerebral Ischemia/Reperfusion Injury by Inhibiting Ferroptosis via SLC7A11/GPX4 Signaling.

Xinglou Chengqi decoction (XLCQD) is a Chinese formula that offers benefits in ischemic stroke. However, the underlying mechanism of the effects of XLCQD-mediated anti-ischemic stroke effects remains obscure. This study investigates the ferroptosis mechanism of XLCQD against cerebral ischemia/reperfusion (I/R) injury using rat models of middle cerebral artery occlusion/reperfusion (MCAO/R). Ferroptosis differs from traditional cell death pathways and is linked to oxidative stress-induced lipid peroxidation and glutathione (GSH) depletion, which is essential to the development of ischemic stroke. In this study, it is shown that XLCQD improves brain infarction, neurological dysfunction, and histopathological changes caused by MCAO/R exposure, and improving I/R-induced oxidative damage through inhibition of ferroptosis via (Solute Carrier Family 7 Member 11) SLC7A11/ (glutathione peroxidase 4) GPX4 pathway. Interestingly, it is found that XLCQD-mediated protection in I/Ris reversed by the silence of SLC7A11. XLCQD intervention significantly promotes GSH content and suppresses Reactive Oxygen Species(ROS), iron accumulation, as well as Malondialdehyde (MDA) generation, are markedly abrogated when SLC7A11 is knockdown by SLC7A11-shRNA transfection, indicating that SLC7A11 is the main target of XLCQD to further trigger intracellular events. In conclusion, XLCQD attenuates in vivo cerebral I/R injury by reducing ferroptosis via the SLC7A11/GPX4 pathway.

NLRP3 Inflammasome Activation Mediates Hepatitis E Virus-Induced Neuroinflammation.

Hepatitis E virus (HEV) is a foodborne zoonotic pathogen that is supposed to be one of the most common causes of acute viral hepatitis. However, HEV infection has been recently associated with a wide spectrum of extrahepatic manifestations, particularly neurological disorders. Previous studies have shown that HEV is able to cross the blood-brain barrier (BBB) and induce inflammatory response of the central nervous system. However, the pathogenesis of HEV-induced neuroinflammation and tissue injury of the central nervous system have yet to be fully elucidated. In this study, activation of NLRP3 inflammasome following HEV infection were investigated. In a gerbil model infected by HEV, brain histopathological changes including gliosis, neuronophagia and neuron injury were observed and expression of NLRP3, caspase-1, IL-1β and IL-18 were elevated. Brain microvascular endothelial cells (BMECs) are key components of the BBB that protects the brain from various challenges. Following HEV infection, virus-like particles range from 30 to 40 nm in diameter were observed in human BMECs (hBMECs). Enhanced expression levels of NLRP3 and subsequent ASC, caspase-1, IL-1β and IL-18 were detected in infected cells. Treatment with MCC950 alleviated HEV infection induced activation of NLRP3 inflammasome, mitochondrial damage and VE-cadherin degradation. The findings provide new insights into HEV-associated neuroinflammation. Moreover, targeting NLRP3 inflammasome signalling is a promising therapeutic in HEV-induced neurological disorder.

Beta vulgaris Betalains Mitigate Parasitemia and Brain Oxidative Stress Induced by Plasmodium berghei in Mice.

Although many drugs have been discovered to treat malaria infection, many of them face resistance from the host's body with long-term use. Therefore, this study aimed to evaluate the activity of betalains (from Beta vulgaris) and chloroquine (a reference drug) against brain oxidative stress induced by Plasmodium berghei in male mice. Two protocols were applied in this study: the therapeutic and prophylactic protocols. The results of the therapeutic protocol revealed a significant decrease in the level of parasitemia caused by P. berghei. Additionally, the histopathological changes in various brain regions were markedly improved after treatment with betalains. Regarding the prophylactic protocol, betalains were able to protect the brain tissues from oxidative stress, inflammation, and disrupted neurotransmitters expected to occur as a result of infection by P. berghei. This was demonstrated by modulating the activities of brain antioxidants (SOD and GSH), inflammatory cytokines (IL-6, IL-10, IL-12, TNF-α, and INF-γ), and neurotransmitters (serotonin, epinephrine, and norepinephrine). This study has proven that using betalains as a treatment or as a preventive has a vital and effective role in confronting the brain histopathological, oxidative stress, and inflammatory changes induced by P. berghei infection.

Network Pharmacology and Transcriptomics to Explore the Pharmacological Mechanisms of 20(S)-Protopanaxatriol in the Treatment of Depression.

Depression is one of the most common psychological disorders nowadays. Studies have shown that 20(S)-protopanaxatriol (PPT) can effectively improve depressive symptoms in mice. However, its mechanism needs to be further explored. In this study, we used an integrated approach combining network pharmacology and transcriptomics to explore the potential mechanisms of PPT for depression. First, the potential targets and pathways of PPT treatment of depression were screened through network pharmacology. Secondly, the BMKCloud platform was used to obtain brain tissue transcription data of chronic unpredictable mild stress (CUMS) model mice and screen PPT-altered differential expression genes (DEGs). Gene ontology (GO) analysis and the Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were performed using network pharmacology and transcriptomics. Finally, the above results were verified by molecular docking, Western blotting, and quantitative real-time polymerase chain reaction (qRT-PCR). In this study, we demonstrated that PPT improved depression-like behavior and brain histopathological changes in CUMS mice, downregulated nitric oxide (NO) and interleukin-6 (IL-6) levels, and elevated serum levels of 5-hydroxytryptamine (5-HT) and brain-derived neurotrophic factor (BDNF) after PPT treatment compared to the CUMS group. Eighty-seven potential targets and 350 DEGs were identified by network pharmacology and transcriptomics. Comprehensive analysis showed that transthyretin (TTR), klotho (KL), FOS, and the phosphatidylinositol 3-kinase-protein kinase B (PI3K-AKT) signaling pathway were closely associated with the therapeutic effects of PPT. Molecular docking results showed that PPT had a high affinity for PI3K, AKT, TTR, KL, and FOS targets. Gene and protein level results showed that PPT could increase the expression of PI3K, phosphorylation of PI3K (p-PI3K), AKT, phosphorylation of AKT (p-AKT), TTR, and KL and inhibit the expression level of FOS in the brain tissue of depressed mice. Our data suggest that PPT may achieve the treatment of depression by inhibiting the expression of FOS, enhancing the expression of TTR and KL, and modulating the PI3K-AKT signaling pathway.

The nongenomic neuroprotective effects of estrogen, E2-BSA, and G1 following traumatic brain injury: PI3K/Akt and histopathological study.

Studies suggest that both genomic and nongenomic pathways are involved in mediating the salutary effects of steroids following traumatic brain injury (TBI). This study investigated the nongenomic effects of 17β-estradiol (E2) mediated by the PI3K/p-Akt pathway after TBI. Ovariectomized rats were apportioned to E2, E2-BSA (E2 conjugated to bovine serum albumin), G1 [G-protein-coupled estrogen receptor agonist (GPER)] or their vehicle was injected following TBI, whereas ICI (classical estrogen receptor antagonist), G15 (GPER antagonist), ICI+G15, and their vehicles were injected before the induction of TBI and injection of drugs. Diffuse TBI was induced by the Marmarou model. Evans blue (EBC, 5 h), brain water contents (BWC), histopathological changes, and brain PI3K and p-Akt protein expressions were measured 24 h after TBI. The veterinary comma scale (VCS) was assessed before and at different times after TBI. The results showed a reduction in BWC and EBC and increased VCS in the E2, E2-BSA, and G1 groups. Also, E2, E2-BSA, and G1 reduced brain edema, inflammation, and apoptosis. The ICI and G15 inhibited the beneficial effects of E2, E2-BSA, and G1 on these parameters. All drugs, following TBI, prevented the reduction of brain PI3K/p-Akt expression. The individual or combined use of ICI and G15 eliminated the beneficial effects of E2, E2-BSA, and G1 on PI3K/p-Akt expressions. These findings indicated that PI3K/p-Akt pathway plays a critical role in mediating the salutary effects of estradiol on histopathological changes and neurological outcomes following TBI, suggesting that GPER and classic ERs are involved in regulating the expression of PI3K/p-Akt.

Examining the Influence of Zinc Oxide Nanoparticles and Bulk Zinc Oxide on Rat Brain Functions: a Comprehensive Neurobehavioral, Antioxidant, Gene Expression, and Histopathological Investigation

The study aimed to assess the impact of zinc oxide nanoparticles (ZnONPs) on rats’ neurobehavior compared to bulk zinc oxide (BZnO). Thirty male Sprague-Dawley rats were randomly assigned to five groups. The control group received Tween 80 (10%), while the ZnONP groups were given ZnONPs at 5 and 10 mg/kg body weight dosages, and the bulk zinc oxide (BZnO) groups received BZnO at the same dosages. Behavioral observations, neurobehavioral examinations, and assessments of brain tissue oxidative markers, neurotransmitter levels, and histopathological changes were performed. The results indicated that ZnONP at a dosage of 5 mg/kg improved general behavior, locomotor activity, memory, and recognition and reduced fearfulness in rats. Conversely, the higher dosage of 10 mg/kg and the bulk form had adverse effects on general behavior, locomotor activity, and learning ability, with the bulk form demonstrating the most severe impact—znONP-5 treatment increased antioxidant enzyme levels and decreased inflammatory markers. BZnO-5 exhibited lower oxidative stress markers, although still higher than BZnO-10. Furthermore, ZnONP-5 and BZnO-5 increased neurotransmitter levels compared to higher dosages. ZnONP-5 upregulated the expression of brain-derived neurotrophic factor (BDNF) mRNA, while BZnO-5 showed increased BDNF mRNA expression and decreased expression of genes related to apoptosis and inflammation. In summary, ZnONPs at 5 mg/kg demonstrated positive effects on rat brain function and behavior, while higher dosages and the bulk form had detrimental effects. In conclusion, the studies emphasized the importance of further assessing various doses and forms of zinc oxide on brain health, highlighting the significance of dosage considerations when using nanomaterials.

Moslosooflavone protects against brain injury induced by hypobaric hypoxic via suppressing oxidative stress, neuroinflammation, energy metabolism disorder, and apoptosis.

To investigate the protect effect of moslosooflavone against brain injury induced by hypobaric hypoxia (HH) in mice. Protective effects of moslosooflavone in oxidative stress, neuroinflammation, energy metabolism disorder, and apoptosis were studied in HH-induced brain damage mice. The pathological morphology in the cortex of mice was determined by hematoxylin and eosin staining. The related protein expressions were detected by western blot. Moslosooflavone improved HH-induced brain histopathological changes, reduced the contents of ROS and MDA, and elevated the levels of antioxidant enzymes and GSH in HH-exposed brains of mice. Moslosooflavone also markedly enhanced the ATPase activities and PK, ATP contents, while reducing LDH activity and the LD, TNF-α, IL-1β, and IL-6 contents HH-exposed brains of mice. In addition, moslosooflavone notably decreased the expression of HIF-1α, VEGF, Bax, and cleaved caspase-3 dramatically increasing the expression of Bcl-2, Nrf2, and HO‑1 in HH-exposed brains of mice. Our current studies indicate that moslosooflavone protects HH-induced brain injury possibly through alleviating oxidative stress and neuroinflammation, maintaining the balance of energy metabolism, and inhibiting cell apoptosis.

Effects of the Toxic Non-Protein Amino Acid β-Methylamino-L-Alanine (BMAA) on Intracellular Amino Acid Levels in Neuroblastoma Cells.

The cyanobacterial non-protein amino acid (AA) β-Methylamino-L-alanine (BMAA) is considered to be a neurotoxin. BMAA caused histopathological changes in brains and spinal cords of primates consistent with some of those seen in early motor neuron disease; however, supplementation with L-serine protected against some of those changes. We examined the impact of BMAA on AA concentrations in human neuroblastoma cells in vitro. Cells were treated with 1000 µM BMAA and intracellular free AA concentrations in treated and control cells were compared at six time-points over a 48 h culture period. BMAA had a profound effect on intracellular AA levels at specific time points but in most cases, AA homeostasis was re-established in the cell. The most heavily impacted amino acid was serine which was depleted in BMAA-treated cells from 9 h onwards. Correction of serine depletion could be a factor in the observation that supplementation with L-serine protects against BMAA toxicity in vitro and in vivo. AAs that could potentially be involved in protection against BMAA-induced oxidation such as histidine, tyrosine, and phenylalanine were depleted in cells at later time points.

Neuroprotective effects of ivermectin against transient cerebral ischemia-reperfusion in rats.

Stroke is a leading cause of disability and death worldwide. Ivermectin is a broad-spectrum anti-parasitic agent with potential anti-bacterial, anti-viral, and anti-cancer effects. However, the effects of ivermectin on the brain are poorly described. This study examined the effects of ivermectin on cerebral ischemia-reperfusion (IR) in rats. A rat model of transient global IR was induced by bilateral carotid artery occlusion for 20min. Rats received ivermectin (2mg/kg/day, ip) one hour after inducing cerebral IR for three consecutive days at 24-h intervals. Next, we examined the effects of ivermectin on brain infarction, histopathology, malondialdehyde levels, myeloperoxidase activity, spatial learning and memory, and phospho-AMPK protein levels. The results showed that ivermectin reduced brain infarct size (P < 0.001) and histopathological changes such as cerebral leukocyte accumulation and edema (P < 0.05) compared to untreated rats with IR. Treatment with ivermectin also decreased myeloperoxidase activity (P < 0.01) and malondialdehyde levels (P < 0.05) while increasing AMPK activity (P < 0.001), memory, and learning compared to the untreated IR group. Overall, we show for the first time that ivermectin conferred neuroprotective effects in a rat model of cerebral IR. Our results indicate that three days of treatment with ivermectin reduced brain infarct size, lipid peroxidation, and myeloperoxidase activity and improved memory and learning in rats with cerebral IR. These effects likely occurred via AMPK-dependent mechanisms.

Efficacy of artesunate combined with Atractylodes lancea or Prabchompoothaweep remedy extracts as adjunctive therapy for the treatment of cerebral malaria

BackgroundCerebral malaria is one of the most serious complications of Plasmodium infection and causes behavioral changes. However, current antimalarial drugs have shown poor outcomes. Therefore, new antimalarials with neuroprotective effects are urgently needed. This study aimed to evaluate the effects of selected extracts as monotherapy or adjunctive therapy with artesunate on antimalarial, anti-inflammatory, antioxidant, and neuroprotective properties in experimental cerebral malaria (ECM).MethodsECM was induced in male C57BL/6 mice by infection with Plasmodium berghei ANKA (PbA). Ethanolic extracts of Atractylodes lancea (a dose of 400 mg/kg) and Prabchompoothaweep remedy (a dose of 600 mg/kg) were evaluated as monotherapy and adjunctive therapy combined with artesunate at the onset of signs of cerebral malaria and continued for 7 consecutive days. Parasitemia, clinical scores, and body weight were recorded throughout the study. At day 13 post-infection, mouse brains were dissected and processed for the study of the inflammatory response, oxidative stress, blood–brain barrier (BBB) integrity, histopathological changes, and neurocognitive impairments.ResultsEthanolic extracts of A. lancea and Prabchompoothaweep remedy alone improved cerebral malaria outcome in ECM, whereas artesunate combined with extracts of A. lancea or Prabchompoothaweep remedy significantly improved the outcome of artesunate and crude extracts alone. Using real-time PCR, PbA-infected mice that had received the combination treatment showed significantly reduced gene expression of inflammatory cytokines (TNF-α, IL-1β, IL-6, and IL-10), chemokines (CXCL4 and CXCL10), and adhesion molecules (ICAM-1, VCAM1, and CD36). The PbA-infected mice that received the combination treatment showed a significantly decreased malondialdehyde level compared to the untreated group. Similarly, the Evans blue dye assay revealed significantly less dye extravasation in the brains of infected mice administered the combination treatment, indicating improved BBB integrity. Combination treatment improved survival and reduced pathology in the PbA-infected group. Additionally, combination treatment resulted in a significantly reduced level of cognitive impairment, which was analyzed using a novel object recognition test.ConclusionsThis study demonstrated that artesunate combined with A. lancea or Prabchompoothaweep remedy extracts as adjunctive therapy reduced mortality, neuroinflammation, oxidative stress, BBB integrity protection, and neurocognitive impairment in the ECM.

MR imaging and outcome in neonatal HIBD models are correlated with sex: the value of diffusion tensor MR imaging and diffusion kurtosis MR imaging.

Hypoxic-ischemic encephalopathy can lead to lifelong morbidity and premature death in full-term newborns. Here, we aimed to determine the efficacy of diffusion kurtosis (DK) [mean kurtosis (MK)] and diffusion tensor (DT) [fractional anisotropy (FA), mean diffusion (MD), axial diffusion (AD), and radial diffusion (RD)] parameters for the early diagnosis of early brain histopathological changes and the prediction of neurodegenerative events in a full-term neonatal hypoxic-ischemic brain injury (HIBD) rat model. The HIBD model was generated in postnatal day 7 Sprague-Dawley rats to assess the changes in DK and DT parameters in 10 specific brain structural regions involving the gray matter, white matter, and limbic system during acute (12 h) and subacute (3 d and 5 d) phases after hypoxic ischemia (HI), which were validated against histology. Sensory and cognitive parameters were assessed by the open field, novel object recognition, elevated plus maze, and CatWalk tests. Repeated-measures ANOVA revealed that specific brain structures showed similar trends to the lesion, and the temporal pattern of MK was substantially more varied than DT parameters, particularly in the deep gray matter. The change rate of MK in the acute phase (12 h) was significantly higher than that of DT parameters. We noted a delayed pseudo-normalization for MK. Additionally, MD, AD, and RD showed more pronounced differences between males and females after HI compared to MK, which was confirmed in behavioral tests. HI females exhibited anxiolytic hyperactivity-like baseline behavior, while the memory ability of HI males was affected in the novel object recognition test. CatWalk assessments revealed chronic deficits in limb gait parameters, particularly the left front paw and right hind paw, as well as poorer performance in HI males than HI females. Our results suggested that DK and DT parameters were complementary in the immature brain and provided great value in assessing early tissue microstructural changes and predicting long-term neurobehavioral deficits, highlighting their ability to detect both acute and long-term changes. Thus, the various diffusion coefficient parameters estimated by the DKI model are powerful tools for early HIBD diagnosis and prognosis assessment, thus providing an experimental and theoretical basis for clinical treatment.

Neuroprotective and Cardiometabolic Role of Vitamin E: Alleviating Neuroinflammation and Metabolic Disturbance Induced by AlCl3 in Rat Models.

Cardiovascular diseases (CVDs) and neurodegenerative disorders, such as diabetes mellitus and Alzheimer's disease, share a common pathophysiological link involving insulin resistance (IR), inflammation, and hypertension. Aluminium chloride (AlCl3), a known neurotoxicant, has been associated with neurodegeneration, cognitive impairment, and various organ dysfunctions due to the production of reactive oxygen species (ROS) and oxidative stress. In this study, we aimed to investigate the potential protective effects of metformin and vitamin E against AlCl3-induced neuroinflammation and cardiometabolic disturbances in rat models. Rats were divided into five groups: a normal control group, an AlCl3-treated diseased group without any treatment, and three groups exposed to AlCl3 and subsequently administered with metformin (100 mg/kg/day) alone, vitamin E (150 mg/kg/day) orally alone, or a combination of metformin (100 mg/kg/day) and vitamin E (150 mg/kg/day) for 45 days. We analyzed serum biomarkers and histopathological changes in brain, heart, and pancreatic tissues using H&E and Masson's trichrome staining and immunohistochemistry (IHC). Electrocardiogram (ECG) patterns were observed for all groups. The AlCl3-treated group showed elevated levels of inflammatory biomarkers, MDA, and disturbances in glycemic and lipid profiles, along with reduced insulin levels. However, treatment with the combination of metformin and vitamin E resulted in significantly reduced glucose, cholesterol, LDL, and TG levels, accompanied by increased insulin and HDL levels compared to the individual treatment groups. Histopathological analyses revealed that combination therapy preserved neuronal structures, muscle cell nuclei, and normal morphology in the brain, heart, and pancreatic tissues. IHC demonstrated reduced amyloid plaques and neurofibrillary tangles in the combination-treated group compared to the AlCl3-treated group. Moreover, the combination group showed a normal ECG pattern, contrasting the altered pattern observed in the AlCl3-treated group. Overall, our findings suggest that metformin and vitamin E, in combination, possess neuroprotective and cardiometabolic effects, alleviating AlCl3-induced neuroinflammation and metabolic disturbances.

Intranasal Nanotransferosomal Gel for Quercetin Brain Targeting: II. Antidepressant Effect in an Experimental Animal Model.

Depression is a serious mental disorder and the most prevalent cause of disability and suicide worldwide. Quercetin (QER) demonstrated antidepressant effects in rats exhibiting anxiety and depressive-like behaviors. In an attempt to improve QER's antidepressant activity, a QER-loaded transferosome (QER-TFS) thermosensitive gel for intranasal administration was formulated and optimized. The therapeutic effectiveness of the optimized formulation was assessed in a depressed rat model by conducting a behavioral analysis. Behavioral study criteria such as immobility, swimming, climbing, sucrose intake, number of crossed lines, rearing, active interaction, and latency to feed were all considerably enhanced by intranasal treatment with the QER-TFS in situ gel in contrast to other formulations. A nasal histopathological study indicated that the QER-TFS thermosensitive gel was safe for the nasal mucosa. An immunohistochemical analysis showed that the animals treated with the QER-TFS thermosensitive gel had the lowest levels of c-fos protein expression, and brain histopathological changes in the depressed rats were alleviated. According to pharmacodynamic, immunohistochemical, and histopathological experiments, the intranasal administration of the QER-TFS thermosensitive gel substantially alleviated depressive symptoms in rats. However, extensive preclinical investigations in higher animal models are needed to anticipate its effectiveness in humans.

Neuroprotective anticonvulsant and anxiolytic effects of octreotide in wistar rats

Somatostatin interneurons exhibited anti-epileptic activity. As a result, somatostatin agonists appear to be a promising target for antiepileptic drug development (AEDs). In this regard, we investigated the effects of octreotide, a somatostatin analog, on pentylenetetrazol (PTZ)-induced seizures in male Wistar rats. Animals were given octreotide at doses of 50 or 100 µg/kg for seven days. The anxiolytic effects of octreotide were then evaluated using open field and elevated plus-maze tests. Following that, mice were intraperitoneally given a single convulsive dosage of PTZ (60 mg/kg) and then monitored for 30 min for symptoms of seizures. Finally, the antioxidant capacity of brain tissue and histopathological changes in the hippocampus were investigated. Octreotide therapy for seven days at 50 or 100 µg/kg was more effective than diazepam in preventing acute PTZ-induced seizures (P < 0.05). Furthermore, both octreotide dosages revealed substantial anxiolytic effects in open-field and elevated plus-maze tests compared to untreated rats. Nonetheless, octreotide's anxiolytic impact was less effective than diazepam's. On the other hand, octreotide also suppressed neuronal apoptosis and attenuated oxidative stress. Our results suggest that chronic administration of octreotide has anticonvulsant, anxiolytic, and antioxidant activity in the male Wistar rat model.

Vitamin K2 protects against aluminium chloride-mediated neurodegeneration.

Recent studies have shown that, coupled with other environmental factors, aluminium exposure may lead to neurodegeneration resulting in cognitive impairment resembling Alzheimer's disease. Menaquinone, a form of vitamin K2, aids in maintaining healthy bones and avoids coronary calcification. It also has anti-inflammatory and antioxidant properties. Here, we study the neuroprotective effects of vitamin K2 (MK-7) using the animal model of Alzheimer's disease (AD). Aluminium chloride (AlCl3; 100mg/kg for 3weeks orally) was administered to Swiss albino mice to induce neurodegeneration and Vitamin K2 (100g/kg for 3weeks orally) was applied as treatment. This was followed by behavioural studies to determine memory changes. The behavioural observations correlated with proinflammatory, oxidative, and brain histopathological changes in AlCl3-treated animals with or without vitamin K2 treatment. AlCl3 administration led to memory decline which was partially restored in Vitamin K2 treated animals. Myeloperoxidase levels in the brain increased due to AlCl3-mediated inflammation, which Vitamin K2 prevented. The acetylcholine esterase and oxidative stress markers induced by AlCl3 were reversed by Vitamin K2. Also, Vitamin K2 helps to restore hippocampal BDNF levels and reduced the amyloid β accumulation in AlCl3-administered animals. Additionally, Vitamin K2 protected the hippocampal neurons against AlCl3-mediated damage as observed in histopathological studies. We conclude that Vitamin K2 could partially reverse AlCl3-mediated cognitive decline. It increases acetylcholine and BDNF levels while reducing oxidative stress, neuroinflammation, and β-amyloid deposition, thus protecting the hippocampal neurons from AlCl3-mediated damage.

Optogenetic stimulation of basal forebrain cholinergic neurons prevents neuroinflammation and neuropsychiatric manifestations in pristane induced lupus mice

BackgroundNeuroinflammation has been identified as one of the primary pathogenic factors of neuropsychiatric systemic lupus erythematosus (NPSLE). However, there are no dedicated treatments available in clinics to alleviate neuroinflammation in NPSLE. It has been proposed that stimulating basal forebrain (BF) cholinergic neurons may provide potent anti-inflammatory effects in several inflammatory diseases, but its potential role in NPSLE remains unexplored. This study aims to investigate whether and how stimulating BF cholinergic neurons has a protective effect on NPSLE.ResultsOptogenetic stimulation of BF cholinergic neurons significantly ameliorated olfactory dysfunction and anxiety- and depression-like phenotype in pristane induced lupus (PIL) mice. The increased expression of adhesion molecules (P-selectin and vascular cell adhesion molecule-1 (VCAM-1)), leukocyte recruitment, blood-brain barrier (BBB) leakage were significantly decreased. Notably, the brain histopathological changes, including the elevated levels of pro-inflammatory cytokines (TNF-α, IL-6 and IL-1β), IgG deposition in the choroid plexus and lateral ventricle wall and lipofuscin accumulation in the cortical and hippocampal neurons, were also significantly attenuated. Furthermore, we confirmed the colocalization between the BF cholinergic projections and the cerebral vessels, and the expression of α7-nicotinic acetylcholine receptor (α7nAChR) on the cerebral vessels.ConclusionOur data indicate that stimulation of BF cholinergic neurons could play a neuroprotective role in the brain through its cholinergic anti-inflammatory effects on cerebral vessels. Therefore, this may be a promising preventive target for NPSLE.

Meloxicam Targets COX-2/NOX1/NOX4/Nrf2 Axis to Ameliorate the Depression-like Neuropathology Induced by Chronic Restraint Stress in Rats.

Meloxicam has shown significant neuroprotection in experimental models of stroke, Alzheimer's disease, and Parkinson's disease. However, the potential of meloxicam to treat depression-like neuropathology in a chronic restraint stress (CRS) model and the associated molecular changes has been insufficiently explored. The current work aimed to explore the potential neuroprotective actions of meloxicam against CRS-evoked depression in rats. In the current experiments, animals received meloxicam (10 mg/kg/day; i.p.) for 21 days, and CRS was instigated by restraining the animals for 6 h/day during the same period. The sucrose preference test and the forced swimming test were used to explore the depression-linked anhedonia/despair, whereas the open-field test examined the animals' locomotor activity. The current findings revealed that CRS elicited typical depression behavioral anomalies in the animals, including anhedonia, despair, and diminished locomotor activity; these findings were reinforced with Z-normalization scores. These observations were corroborated by brain histopathological changes and increased damage scores. In CRS-exposed animals, serum corticosterone spiked, and the hippocampi revealed decreased monoamine neurotransmitter levels (norepinephrine, serotonin, and dopamine). Mechanistically, neuroinflammation was evident in stressed animals, as shown by elevated hippocampal TNF-α and IL-1β cytokines. Moreover, the hippocampal COX-2/PGE2 axis was activated in the rats, confirming the escalation of neuroinflammatory events. In tandem, the pro-oxidant milieu was augmented, as seen by increased hippocampal 8-hydroxy-2'-deoxyguanosine alongside increased protein expression of the pro-oxidants NOX1 and NOX4 in the hippocampi of stressed animals. In addition, the antioxidant/cytoprotective Nrf2/HO-1 cascade was dampened, as evidenced by the lowered hippocampal protein expression of Nrf2 and HO-1 signals. Interestingly, meloxicam administration mitigated depression manifestations and brain histopathological anomalies in the rats. These beneficial effects were elicited by meloxicam's ability to counteract the corticosterone spike and hippocampal neurotransmitter decrease while also inhibiting COX-2/NOX1/NOX4 axis and stimulating Nrf2/HO-1 antioxidant pathway. Together, the present findings prove the neuroprotective/antidepressant actions of meloxicam in CRS-induced depression by ameliorating hippocampal neuroinflammation and pro-oxidant changes, likely by modulating COX-2/NOX1/NOX4/Nrf2 axis.

Circ-Gucy1a2 Protects Mice from Cerebral Ischemia-Reperfusion Injury by Attenuating Neuronal Apoptosis and Mitochondrial Membrane Potential Loss

Cerebral ischemia-reperfusion (I/R) injury (CI/RI) is a severe problem in patients with cerebral ischemia. The current study explored the influences of circular (circ)-Gucy1a2 on neuronal apoptosis and mitochondrial membrane potential (MMP) in the brain tissue of CI/RI mice. Forty-eight mice were randomized into the sham group, transient middle cerebral artery occlusion (tMCAO) group, lentivirus negative control (LV-NC) group, and LV-Gucy1a2 group. Mice were first injected with lentivirus loaded with LV-Gucy1a2 or LV-NC via lateral ventricle, followed by the establishment of CI/RI models 2 weeks later. Twenty-four hours after CI/RI, the neurological impairment of mice was assessed using a 6-point scoring system. The cerebral infarct volume and brain histopathological changes were determined in CI/RI mice through histological staining. In vitro, pcDNA3.1-NC and pcDNA3.1-Gucy1a2 were transfected into mouse primary cortical neurons for 48 hours, followed by the establishment of oxygen-glucose deprivation/reoxygenation (OGD/R) models. The levels of circ-Gucy1a2 in mouse brain tissues and neurons were examined using RT-qPCR. Neuronal proliferation and apoptosis, MMP loss, and oxidative stress (OS)-related indexes in neurons were detected using CCK-8 assay, flow cytometry, JC-1 staining, and H2DFFDA staining. CI/RI mouse models and OGD/R cell models were successfully established. After CI/RI, neurons in mice were impaired and the cerebral infarction volume was increased. circ-Gucy1a2 was poorly expressed in CI/RI mouse brain tissues. Overexpression of circ-Gucy1a2 increased OGD/R-induced neuronal proliferation and mitigated apoptosis, MMP loss, and OS. Overall, circ-Gucy1a2 was down-regulated in brain tissues of CI/RI mice, and overexpression of circ-Gucy1a2 can protect mice from CI/RI.

Neuroprotective effect of Vitamin K2 against gut dysbiosis associated cognitive decline

Vitamin K2/ Menaquinones produced predominantly by the gut microbiome improve bone health and prevent coronary calcification. The central nervous system has been linked with gut microbiota via the gut-brain axis and is strongly associated with psychiatric conditions. In the present study, we show the role of Vitamin K2 (MK-7) in gut dysbiosis-associated cognitive decline. Gut dysbiosis was induced in mice by administering Ampicillin (250 mg/kg twice a day orally) for 14 days and Vitamin K2 (0.05 mg/kg) for 21 days with or without antibiotic treatment and altered gene expression profile of intestinal microbes determined. This was followed by behavioural studies to determine cognitive changes. The behavioural observations are then correlated with proinflammatory, oxidative, and brain and intestinal histopathological changes in antibiotic-treated animals with or without vitamin K2 administration. With the use of antibiotics, Lactobacillus, Bifidobacterium, Firmicutes, and Clostridium's relative abundance reduced. When vitamin K2 was added to the medication, their levels were restored. Cognitive impairment was observed in behavioural trials in the antibiotic group, but this drop was restored in mice given both an antibiotic and vitamin K. Myeloperoxidase levels in the colon and brain increased due to gut dysbiosis, which vitamin K2 prevented. The acetylcholine esterase and oxidative stress markers brought on by antibiotics were also decreased by vitamin K2. Additionally, vitamin K2 guarded against alterations in intestine ultrastructure brought on by antibiotic use and preserved hippocampus neurons. So, it can be concluded that vitamin K2 improved cognitive skills, avoided hippocampus neuronal damage from antibiotics, and lowered intestine and brain inflammation and oxidative stress.

Radix Rehmanniae Praeparata (Shu Dihuang) exerts neuroprotective effects on ICV-STZ-induced Alzheimer's disease mice through modulation of INSR/IRS-1/AKT/GSK-3β signaling pathway and intestinal microbiota.

Radix Rehmanniae Praeparata (RRP, Shu Dihuang in Cinese) is widely used as primal medicine in Chinese herbal formula for the treatment of Alzheimer's disease (AD). However, the underlying mechanism of RRP for AD remains unclear. The aim of this study was to investigate the therapeutic effect of RRP on intracerebroventricular injection of streptozotocin (ICV-STZ)-induced AD model mice and its potential mechanism. ICV-STZ mice were continuously gavaged with RRP for 21days. The pharmacological effects of RRP were evaluated by behavioral tests, brain tissue H&E staining and hippocampal tau protein phosphorylation levels. The expression levels of insulin receptor (INSR), IRS-1, pSer473-AKT/AKT and pSer9-GSK-3β/GSK-3β proteins in hippocampal and cortical tissues were detected by Western-blot method. The 16S rRNA gene sequencing was used to analyze the changes of intestinal microbiota in mice. The compounds in RRP were analyzed by mass spectrometry and their binding ability to INSR proteins was detected by molecular docking. The results showed that RRP ameliorated cognitive dysfunction and neuronal pathological changes of brain tissue in ICV-STZ mice, reduced tau protein hyperphosphorylation, INSR, IRS-1, pSer473-AKT/AKT, and pSer9-GSK-3β/GSK-3β levels in hippocampal and cortical tissues. Meanwhile, RRP reversed ICV-STZ-induced dysregulation of intestinal microbiota in AD mice. Mass spectrometry analysis showed that the RRP consisted mainly of seven compounds, namely Acteoside (Verbascoside), 5-Hydroxymethyl-2-furaldehyde (5-HMF), Apigenin7-O-glucuronide, Icariin, Gallic acid, Quercetin-3β-D-glucoside, and Geniposide. Molecular docking results further indicated that the compounds in RRP have binding ability to INSR protein and potential multiple synergistic effects. RRP ameliorates cognitive dysfunction and brain histopathological changes in AD mice. The mechanism of RRP ameliorating AD may be related to the regulation of INSR/IRS-1/AKT/GSK-3β signaling pathway and intestinal microbiota. This study supports the potential anti-AD efficacy of RRP and initially reveals the pharmacological mechanism of RRP, providing a theoretical basis for further clinical application of RRP.