Oxiracetam alleviates anti-inflammatory activity and ameliorates cognitive impairment in the early phase of traumatic brain injury.

BACKGROUND: We aimed to investigate the effects of oxiracetam on cognitive impairment in the early phase of traumatic brain injury (TBI), for which no specific treatment is currently available. METHODS: The in vitro study used a cell injury controller to damage SH-SY5Y cells and evaluate the effect of oxiracetam at a dosage of 100 nM. The in vivo study used a stereotaxic impactor to induce a TBI model in C57BL/6 J mice and analyzed immunohistochemical changes and cognitive function after an intraperitoneal injection of oxiracetam (30 mg/kg/day) for 5 days. The number of mice used in this study was 60. They were divided into three groups (sham, TBI, and TBI with oxiracetam treatment) (20 mice in each group). RESULTS: The in vitro study showed that oxiracetam treatment resulted in increased superoxide dismutase (SOD)1 and SOD2 mRNA expression. The mRNA and protein expression of COX-2, NLRP3, caspase-1, and interleukin (IL)-1 ß were decreased after oxiracetam treatment, along with decreases in intracellular reactive oxygen species production and apoptotic effects. TBI mice treated with oxiracetam exhibited the loss of fewer cortical damaged lesions, less brain edema, and fewer Fluoro-Jade B (FJB)-positive and terminal deoxynucleotidyl transferase dUTP nick end-labeling (TUNEL)-positive cells compared to those without oxiracetam treatment. The mRNA and protein expression of COX-2, NLRP3, caspase-1, and IL-1ß were decreased significantly after oxiracetam treatment. These inflammation-related markers, which colocalized with Iba-1-positive or GFAP-positive cells after TBI, were also decreased after oxiracetam treatment. TBI mice treated with oxiracetam had a smaller decrease in preference and more latency time than those not treated with oxiracetam, suggesting the amelioration of impaired cognitive impairment. CONCLUSIONS: Oxiracetam may be helpful in restoring cognitive impairment by ameliorating neuroinflammation in the early phase of TBI.

Human embryonic stem cell-derived cerebral organoids for treatment of mild traumatic brain injury in a mouse model.

OBJECTIVE: There are no effective treatments for relieving neuronal dysfunction after mild traumatic brain injury (TBI). Here, we evaluated therapeutic efficacy of human embryonic stem cell-derived cerebral organoids (hCOs) in a mild TBI model, in terms of repair of damaged cortical regions, neurogenesis, and improved cognitive function. METHODS: Male C57BL/6 J mice were randomly divided into sham-operated, mild TBI, and mild TBI with hCO groups. hCOs cultured at 8 weeks were used for transplantation. Mice were sacrificed at 7 and 14 days after transplantation followed by immunofluorescence staining, cytokine profile microarray, and novel object recognition test. RESULTS: 8W-hCOs transplantation significantly reduced neuronal cell death, recovered microvessel density, and promoted neurogenesis in the ipsilateral subventricular zone and dentate gyrus of hippocampus after mild TBI. In addition, increased angiogenesis into the engrafted hCOs was observed. Microarray results of hCOs revealed neuronal differentiation potential and higher expression of early brain development proteins associated with neurogenesis, angiogenesis and extracellular matrix remodeling. Ultimately, 8W-hCO transplantation resulted in reconstruction of damaged cortex and improvement in cognitive function after mild TBI. CONCLUSION: hCO transplantation may be feasible for treating mild TBI-related neuronal dysfunction via reconstruction of damaged cortex and neurogenesis in the hippocampus.

Glutamine deficiency in the prefrontal cortex increases depressive-like behaviours in male mice.

BACKGROUND: The brain levels of glutamate (Glu) and glutamine (Gln) are partially regulated through the Glu-Gln cycle. Astrocytes play a role in regulating the Glu-Gln cycle, and loss of astrocytes has been associated with depressive disorders. We hypothesized that levels of Glu and Gln would be affected by astrocyte loss and dysregulation of the Glu-Gln cycle and that depressive-like behaviours would be closely related to the level of changes in Glu and Gln. METHODS: We used liquid chromatography to measure Glu and Gln concentrations in the prefrontal cortex of male mice infused with L-α aminoadipic acid (L-AAA), a specific astrocyte toxin, in the prelimbic cortex. Methionine sulfoximine, a Gln synthetase inhibitor, and α-methyl-amino-isobutyric acid, a blocker of neuronal Gln transporters, were used to disturb the Glu-Gln cycle. We assessed the behavioural change by drug infusion using the forced swim test (FST) and sucrose preference test. RESULTS: The Glu and Gln levels were decreased on the fifth day after L-AAA infusion, and the infused mice showed longer durations of immobility in the FST and lower sucrose preference, indicative of depressive-like behaviour. Mice in which Gln synthetase or Gln transport were inhibited also exhibited increased immobility in the FST. Direct infusion of L-Gln reversed the increased immobility induced by astrocyte ablation and Glu-Gln cycle impairments. LIMITATIONS: Genetically modified animal models and diverse behavioural assessments would have been helpful to solidify our conclusions. CONCLUSION: Neuronal Gln deficiency in the prefrontal cortex may cause depressive behaviours.

WITHDRAWN: Effect of Therapeutic Hypothermia on Cognitive Impairment in a Mouse Model of Ischemia-Reperfusion Injury.

Ahead of Print article withdrawn by publisher.

Therapeutic effect of a hydrogel-based neural stem cell delivery sheet for mild traumatic brain injury.

OBJECTIVE: There are no effective clinically applicable treatments for neuronal dysfunction after mild traumatic brain injury (TBI). Here, we evaluated the therapeutic effect of a new delivery method of mouse neural stem cell (mNSC) spheroids using a hydrogel, in terms of improvement in damaged cortical lesions and cognitive impairment after mild TBI. METHODS: mNSCs were isolated from the subventricular zone and subgranular zone by a hydrogel-based culture system. GFP-transduced mNSCs were generated into spheroids and wrapped into a sheet for transplantation. Male C57BL/6J mice were randomly divided into four groups: sham operation, TBI, TBI with mNSC spheroids, and TBI with mNSC spheroid sheet transplantation covering the damaged cortex. Histopathological and immunohistochemical features and cognitive function were evaluated 7, 14, and 28 days after transplantation following TBI. RESULTS: Hydrogel-based culture systems and mNSC isolation were successfully established from the adult mice. Essential transcription factors for NSCs, such as SOX2, PAX6, Olig2, nestin, and doublecortin (DCX), were highly expressed in the mNSCs. A transplanted hydrogel-based mNSC spheroid sheet showed good engraftment and survival ability, differentiated into TUJ1-positive neurons, promoted angiogenesis, and reduced neuronal degeneration. Also, TBI mice treated with mNSC spheroid sheet transplantation exhibited a significantly increased preference for a new object, suggesting improved cognitive function compared to the mNSC spheroids or no treatment groups. CONCLUSION: Transplantation with a hydrogel-based mNSC spheroid sheet showed engraftment, migration, and stability of delivered cells in a hostile microenvironment after TBI, resulting in improved cognitive function via reconstruction of the damaged cortex. STATEMENT OF SIGNIFICANCE: This study presents the therapeutic effect of a new delivery method of mouse neural stem cells spheroids using a hydrogel, in terms of improvement in damaged cortical lesions and cognitive impairment after traumatic brain injury. Collagen/fibrin hydrogel allowed long-term survival and migratory ability of NSCs spheroids. Furthermore, transplanted hydrogel-based mNSCs spheroids sheet showed good engraftment, migration, and stability of delivered cells in a hostile microenvironment, resulting in reconstruction of the damaged cortex and improved cognitive function after TBI. Therefore, we suggest that a hydrogel-based mNSCs spheroids sheet could help to improve cognitive impairment after TBI.

Updated Trans-Ethnic Meta-Analysis of Associations between Inflammation-Related Genes and Intracranial Aneurysm.

OBJECTIVE: We performed an expanded multi-ethnic meta-analysis to identify associations between inflammation-related loci with intracranial aneurysm (IA) susceptibility. This meta-analysis possesses increased statistical power as it is based on the most data ever evaluated. METHODS: We searched and reviewed relevant literature through electronic search engines up to August 2022. Overall estimates were calculated under the fixed- or random-effect models using pooled odds ratio (OR) and 95% confidence intervals (CIs). Subgroup analyses were performed according to ethnicity. RESULTS: Our meta-analysis enrolled 15 studies and involved 3070 patients and 5528 controls including European, Asian, Hispanic, and mixed ethnic populations. Of 17 inflammation-related variants, the rs1800796 locus (interleukin [IL]-6) showed the most significant genome-wide association with IA in East-Asian populations, including 1276 IA patients and 1322 controls (OR, 0.65; 95% CI, 0.56-0.75; p=3.24×10-9) under a fixed-effect model. However, this association was not observed in the European population (OR, 1.09; 95% CI, 0.80-1.47; p=0.5929). Three other variants, rs16944 (IL-1ß), rs2195940 (IL-12B), and rs1800629 (tumor necrosis factor-α) showed a statistically nominal association with IA in both the overall, as well as East-Asian populations (0.01

Decreased expression of extracellular matrix proteins and trophic factors in the amygdala complex of depressed mice after chronic immobilization stress.

BACKGROUND: The amygdala plays an essential role in controlling emotional behaviors and has numerous connections to other brain regions. The functional role of the amygdala has been highlighted by various studies of stress-induced behavioral changes. Here we investigated gene expression changes in the amygdala in the chronic immobilization stress (CIS)-induced depression model. RESULTS: Eight genes were decreased in the amygdala of CIS mice, including genes for neurotrophic factors and extracellular matrix proteins. Among these, osteoglycin, fibromodulin, insulin-like growth factor 2 (Igf2), and insulin-like growth factor binding protein 2 (Igfbp2) were further analyzed for histological expression changes. The expression of osteoglycin and fibromodulin simultaneously decreased in the medial, basolateral, and central amygdala regions. However, Igf2 and Igfbp2 decreased specifically in the central nucleus of the amygdala. Interestingly, this decrease was found only in the amygdala of mice showing higher immobility, but not in mice displaying lower immobility, although the CIS regimen was the same for both groups. CONCLUSIONS: These results suggest that the responsiveness of the amygdala may play a role in the sensitivity of CIS-induced behavioral changes in mice.

Angelica tenuissima Nakai Ameliorates Cognitive Impairment and Promotes Neurogenesis in Mouse Model of Alzheimer's Disease.

OBJECTIVE: To research Angelica tenuissima Nakai (ATN) for use in novel Alzheimer's disease (AD) therapeutics. METHODS: The effect of a 30% ethanol extract of ATN (KH032) on AD-like cognitive impairment and neuropathological and neuroinflammatory changes induced by bilateral intracerebroventricular injections of ß-amyloid (Aß) peptide (Aß1-42) was investigated. Male C57Bl/6 mice were randomly divided into 4 groups, 10 in each group. KH032-treated groups were administrated with a low or high dose of KH032 (50 and 200 mg/kg, respectively), intragastrically for 16 days; distilled water was applied in the sham and negative groups. Open fifield test, Y maze and Morris water maze test were used for behavior test and cognitive ability. In addition, the neuroprotective effects of KH032 in Aß1-42-infused mice on the histopathological markers [neuronspecific nuclear protein (NeuN), Aß1-42] of neurodegeneration were examined. The levels of glial fibrillary acidic protein (GFAP), NeuN, phosphorylation extracellular signal-regulated kinase (ERK)/ERK, brain-derived neurotrophic factor (BDNF), phosphorylation cAMP response element-binding (CREB)/CREB protein expression were measured by Western blot. RESULTS: KH032 treatment ameliorated cognitive impairments, reduced the overexpression of Aß1-42, and inhibited neuronal loss and neuroinflammatory response in the Aß1-42-infused mice. Moreover, KH032 treatment enhanced BDNF expression levels in the hippocampus. Finally, KH032 treatment increased phosphorylation of ERK1/2 and CREB, vital for ERK-CREB signaling. CONCLUSIONS: KH032 attenuated cognitive defificits in the Aß1-42-infused mice by increasing BDNF expression and ERK1/2 and CREB phosphorylation and inhibiting neuronal loss and neuroinflflammatory response, suggesting that KH032 has therapeutic potential in neurodegenerative disorders such as AD.

Transplantation of porcine umbilical cord matrix mesenchymal stem cells in a mouse model of Parkinson's disease.

The present study compared mesenchymal stem cells derived from umbilical cord matrix (UCM-MSCs) with bone marrow (BM-MSCs) of miniature pigs on their phenotypic profiles and ability to differentiate in vitro into osteocytes, adipocytes and neuron-like cells. This study further evaluated the therapeutic potential of UCM-MSCs in a mouse Parkinson's disease (PD) model. Differences in expression of some cell surface and cytoplasm specific markers were evident between UCM-MSCs and BM-MSCs. However, the expression profile indicated the primitive nature of UCM-MSCs, along with their less or non-immunogenic features, compared with BM-MSCs. In vitro differentiation results showed that BM-MSCs had a higher tendency to form osteocytes and adipocytes, whereas UCM-MSCs possessed an increased potential to transform into immature or mature neuron-like cells. Based on these findings, UCM-MSCs were transplanted into the right substantia nigra (SN) of a mouse PD model. Transplantation of UCM-MSCs partially recovered the mouse PD model by showing an improvement in basic motor behaviour, as assessed by rotarod and bridge tests. These observations were further supported by the expression of markers, including nestin, tyrosine hydroxylase (TH), neuronal growth factor (NGF), vascular endothelial growth factor (VEGF) and interleukin-6 (IL-6), at the site of cell transplantation. Our findings of xenotransplantation have collectively suggested the potential utility of UCM-MSCs in developing viable therapeutic strategies for PD.

Resveratrol attenuates obesity-associated peripheral and central inflammation and improves memory deficit in mice fed a high-fat diet.

Obesity-induced diabetes is associated with chronic inflammation and is considered a risk factor for neurodegeneration. We tested the hypothesis that an AMP-activated protein kinase activator, resveratrol (RES), which is known to exert potent anti-inflammatory effects, would attenuate peripheral and central inflammation and improve memory deficit in mice fed a high-fat diet (HFD). C57BL/6J mice were fed an HFD or an HFD supplemented with RES for 20 weeks. Metabolic parameters in serum were evaluated, and Western blot analysis and immunohistochemistry in peripheral organs and brain were completed. We used the Morris water maze test to study the role of RES on memory function in HFD-treated mice. RES treatment reduced hepatic steatosis, macrophage infiltration, and insulin resistance in HFD-fed mice. In the hippocampus of HFD-fed mice, the protein levels of tumor necrosis factor-α and Iba-1 expression were reduced by RES treatment. Choline acetyltransferase was increased, and the phosphorylation of tau was decreased in the hippocampus of HFD-fed mice upon RES treatment. In particular, we found that RES significantly improved memory deficit in HFD-fed mice. These findings indicate that RES reverses obesity-related peripheral and central inflammation and metabolic derangements and improves memory deficit in HFD-fed diabetic mice.

Acute stress responsive RGS proteins in the mouse brain.

Regulator of G-protein signaling (RGS) proteins play an important role in G-protein coupled receptor (GPCR) signaling and the activity of some GPCRs is modulated via RGS protein levels during stress response. The aim of this study was to investigate changes in RGS protein mRNA expressions in the mouse brain after 2h restraint stress. The mRNA level of 19 RGS proteins was analyzed using real-time PCR in six brain regions, which included the prefrontal cortex, amygdala, hippocampus, hypothalamus, striatum, and pituitary gland, from control and stressed mouse. We found that the level of mRNA of each RGS varied according to brain region and that two to eight RGS proteins exhibited changes in mRNA levels in each brain region by restraint stress. It was also revealed that RGS4 protein amount was consistent with mRNA level, indicating RGS4 protein may have regulatory roles in the acute stress response.