Iba1 Expression Research Articles

CB1 Receptor Activation Provides Neuroprotection in an Animal Model of Glutamate-Induced Excitotoxicity Through a Reduction of NOX-2 Activity and Oxidative Stress.

Excitotoxicity is a process in which NADPH oxidase-2 (NOX-2) plays a pivotal role in the generation of reactive oxygen species (ROS). Oxidative stress influences the expression of Aquaporin 4 (AQP4), a water channel implicated in blood-brain barrier (BBB) permeability and edema formation. The endocannabinoid system is widely distributed in the brain, particularly through the cannabinoid receptor type 1 (CB1) and type 2 (CB2), which have been shown to have a neuroprotective function in brain injury. Given the significant involvement of NOX-2 in ROS production during excitotoxicity, our research aims to assess the participation of NOX-2 in the neuroprotective effect of the cannabinoid receptor agonist WIN55,212-2 against glutamate-induced excitotoxicity damage in the striatum using invivo model. Wild-type mice (C57BL/6) and NOX-2 KO (gp91Cybbtm1Din/J) were stereotactically injected in the striatum with monosodium glutamate or vehicle. Subsequently, a group of mice was administered an intraperitoneal dose of WIN55,212-2, AM251, or AM251/WIN55,212-2 following the intracerebral injection. Motor activity was assessed, and the lesion was examined through histological sections stained with cresyl violet. Additionally, brain water content and Evans blue assay were conducted. The activity of NOX was quantified, and the protein expression of CB1, gp91phox, AQP4, Iba-1, TNF-α, and NF-κB was analyzed using Western blot. Furthermore, ROS formation was measured through the DHE assay. The activation of the endocannabinoid receptors demonstrated a neuroprotective response during excitotoxicity, meditated by NOX-2. The reduction in ROS production led to a decrease in neuroinflammation, and AQP4 expression, resulting in reduced edema formation, and BBB permeability. During excitotoxic damage, WIN55,212-2 inhibits NOX-2-induced ROS production, reducing brain injury.

Daidzein ameliorates experimental traumatic brain injury-induced neurological symptoms by suppressing oxidative stress and apoptosis.

Traumatic brain injury (TBI) causes deficits in neurological function, induces pathological changes, and increases oxidative stress. The current investigation aimed to determine Daidzein's neuroprotective potential in experimental TBI. Initially, the HT-22 cell line exposed to H2O2 underwent in vitro examination, and the results showed that Daidzein had a neuroprotective effect evident from enhanced cell viability and decreased NO generation. Using three different Daidzein doses-1 mg/kg, 5 mg/kg, and 10 mg/kg-in the in vivo experiment, the potential of Daidzein was evaluated against TBI. The neurological severity score (NSS), kondziela's screen test, and elevated plus maze showed improvements after treatment with Daidzein manifested by decreased score, enhanced motor coordination, and anti-anxiety effects. Additionally, Daidzein improved mechanical allodynia and restored the breakdown of the blood-brain barrier. The FTIR spectral analysis showed restoration of the biochemical compositional changes. Furthermore, H & E and Toluidine blue staining revealed an improvement in the histopathological alterations. The RT-qPCR revealed an increase in mRNA expression level of Nrf2, HO-1, and Bcl-2 and the downregulation of Keap-1, Bax and Cleaved caspase-3 expressions. Thus, exhibiting its antioxidant and antiapoptotic potential. The RT-qPCR also manifested a decrease in mRNA expression of GFAP and Iba-1. Further immunohistochemistry results indicated Daidzein's antioxidant and antiapoptotic properties by upregulating Nrf2 and downregulating cleaved caspase-3. Daidzein also lowered the apoptosis index and improved neuronal survival evidenced by flow cytometric analysis. In addition to this, Daidzein notably increased the antioxidant enzyme levels and decreased the oxidative stress markers. The current study's findings point to the neuroprotective potential of the phytoestrogen Daidzein as it lessened neurological abnormalities, decreased oxidative stress, and lowered proapoptotic protein expression.

Semaglutide ameliorates Alzheimer's disease and restores oxytocin in APP/PS1 mice and human brain organoid models

AimsTo investigate the therapeutic effects and mechanisms of Semaglutide in Alzheimer's disease (AD), and identify its potential targets. MethodsWe systematically evaluated the effect of Semaglutide on Alzheimer's disease (AD), using both mice and human organoid models. ResultsBehavioral analyses on APP/PS1 mice demonstrated that Semaglutide improved the cognitive capabilities, particularly in the learning and memory domains. Biochemical investigations further highlighted its role in reducing amyloid plaque deposition and down-regulating the expression of glial fibrillary acidic protein (GFAP) and ionized calcium binding adaptor molecule 1 (Iba1) expression in the mouse brain tissues. Meanwhile, oxytocin (OXT) was up-regulated after Semaglutide treatment. Subsequent studies using human AD-brain organoids (BOs) models revealed that, upon Semaglutide treatment, these AD-BO models also exhibited reduced levels of amyloid-beta (Aβ), phosphorylated Tau (p-Tau) and GFAP expression as well as increased OXT level. ConclusionsSemaglutide can ameliorate Alzheimer's disease in pre-clinical models, suggesting the promising therapeutic potential in AD patients.

Evaluation of TRPM2 Channel-Mediated Autophagic Signaling Pathway in Hippocampus and Cortex Tissues of Rat Offspring Following Prenatal Exposure to Elevated Alcohol Levels.

Fetal alcohol syndrome (FAS) can occur because of high amount of alcohol intake during pregnancy and is characterized by both physical and neurological problems. Children diagnosed with FAS have difficulties in learning, memory, and coordination. Hippocampus has a major role in memory and learning. We aimed to determine whether alcohol exposure during pregnancy had any effect on offspring by evaluating learning ability as well as oxidative stress and autophagy in the hippocampus and cortex tissues of litters. Attention was also paid to sex differences. To do so, TRPM2, Beclin1, p62, LC3B, IBA1, parvalbumin, GAD65, and mGluR5 expression levels were evaluated by immunohistochemistry. Lactate dehydrogenase (LDH), and malondialdehyde (MDA) levels, as well as total oxidant (TOS) and total antioxidant (TAS) status were determined by ELISA. Learning experiments were evaluated by the Morris water maze (MWM) test. Our findings demonstrated that IBA1, LC3B, GAD65, and mGluR5 expression levels were higher in female rats of the chronic alcohol exposure (CAE) model. Our IHC results revealed that TRPM2 expression levels were significantly increased in both males and females in the CAE group. Likewise, TAS was lower, and TOS was higher in CAE animals. Moreover, MWM outcomes supported a learning deficiency in CAE litters compared to controls and indicated that female offspring outperformed males in learning experiments. Therefore, our results revealed the detrimental effects of alcohol exposure during pregnancy on autophagy signaling in the hippocampus and cortex tissue of litters, which could affect the learning ability of animals.

Neuroprotective effects of psilocybin in a rat model of stroke

BackgroundPsilocybin is a psychedelic 5HT2A receptor agonist found in “magic mushrooms”. Recent studies have indicated that 5HT2A agonists, such as dimethyltryptamine, given before middle cerebral artery occlusion (MCAo), improve staircase behavior, increased BDNF expression, and reduce brain infarction in stroke rats. The objective of this study is to determine the protective effect of psilocybin in cellular and animal models of stroke.MethodsAdult male and timed-pregnant Sprague-Dawley rats were used for this study. The neural protective effects of psilocybin were determined in primary rat cortical neurons and adult rats. Rats were subjected to a 60-min middle cerebral artery occlusion. Brain tissues were collected for histological and qRTPCR analysis.ResultsPsilocybin reduced glutamate-mediated neuronal loss in rat primary cortical neuronal cultures. Psilocybin-mediated protection in culture was antagonized by the BDNF inhibitor ANA12. Pretreatment with psilocybin reduced brain infarction and neurological deficits in stroke rats. Early post-treatment with psilocybin improved locomotor behavior, upregulated the expression of MAP2 and synaptophysin, and down-regulated the expression of IBA1 in the stroke brain. ANA12 significantly attenuated psilocybin-mediated reduction in brain infarction and improvements in locomotor behavior.ConclusionsPsilocybin reduced brain infarction and improved locomotor behavior in stroke rats; the protective mechanisms involve regulating BDNF expression. Our data support a novel therapeutic approach of psilocybin in stroke.

Vagus nerve stimulation with a small total charge transfer improves motor behavior and reduces neuroinflammation in a mouse model of Parkinson's disease

Parkinson's disease (PD) is a common neurodegenerative disease characterized by the loss of dopaminergic (DA) neurons in the substantia nigra (SN). Conventional treatments are ineffective in reversing disease progression. Recently, the therapeutic and rehabilitation potential of vagus nerve stimulation (VNS) in PD has been explored. However, the underlying mechanisms remain largely unknown. In this study, we investigated the neuroprotective effects of VNS in a lateral lesioned mice model of PD. Excluding controls, experimental mice received cuff electrode implantation on the left vagus nerve and 6-hydroxydopamine administration into the bilateral striatum. After ten days, electrical stimulation was delivered for 11 consecutive days onto PD animals. Behavioral tests were performed after stimulation. The expression of TH, Iba-1, GFAP, adrenergic receptors and cytokines in the SN and striatum was detected by immunofluorescence or western blotting. The activity of noradrenergic neurons in the locus coeruleus (LC) was also measured. Our results suggest that VNS improved behavioral performance in rod rotation, open field tests and pole-climbing tests in PD mice, accompanied by a decrease in the loss of dopaminergic neurons in the SN and increased TH expression in the striatum. Neuroinflammation-related factors, such as GFAP, Iba-1, TNF-α and IL-1β were also suppressed in PD mice after VNS compared to those without treatment. Furthermore, the proportion of c-Fos-positive noradrenergic neurons in the LC increased when animals received VNS. Additionally, the expression of the adrenergic receptor of α1BR was also upregulated after VNS compared to PD mice. In conclusion, VNS has potential as a novel PD therapy for neuroprotective effects, and indicate that activation of norepinephric neurons in LC may plays an important role in VNS treatment for PD.

Lignans of Schisandra chinensis (Turcz.) Baill inhibits Parkinson's disease progression through mediated neuroinflammation-TRPV1 expression in microglia

BackgroundSchisandra chinensis (Turcz.) Baill (S. chinensis), a member of the Magnoliaceae family, is renowned for its distinctive medicinal attributes and is commonly employed in the treatment of disorders affecting the CNS. PurposeThe potential therapeutic effects of a lignan-enriched extract derived from Schisandra chinensis (Turcz.) Baill (LSC) on PD is assessed, which focuses on its mechanisms of action in addressing neuroinflammation. MethodsThe LSC has been obtained by purifying the ethyl alcohol extract of S. chinensis. The Orbitrap-MS method has been employed to analyze the chemical composition of the LSC. In LPS-induced BV2 cells, LSC-induced changes in M1/M2 type inflammatory cytokines have been examined using the Griess reaction, Elisa, JC-1, flow cytometry, IF, and WB methods. A model of PD has been established by treatment of MPTP in C57BL/6 mice. The effect of LSC on behavioral changes, inflammatory factor levels, expression of TH and IBA-1, and production of autophagy in the midbrain has been investigated by TEM, immunohistochemistry, Elisa, and WB. ResultsLSC has relieved sports injuries and pathological damage, and targeted the TRPV1-AMPK-NLRP3 signaling pathway, which affected neuroinflammation and autophagy in vivo. Furthermore, in vitro investigations demonstrated that LSC has activated M1/M2 transformation, its related inflammatory factors, and protein expressions of the NLRP3-Caspase1 signaling pathway in LPS-BV2 cells. The research notably demonstrated that the LSC promoted autophagy and suppressed inflammation through targeting TRPV1. ConclusionIn the investigation, LSC focused on TRPV1 and controlled neuroinflammation-autophagy by regulating AMPK-NLRP3, which has been proven for the first time. The study has presented molecular data supporting the use of LSC in treating PD and offers references for developing drugs. Remarkably, LSC has the potential to be utilized as a therapeutic or health medication that could significantly decrease PD.

Bile duct ligation impairs visual acuity in rats by ammonia- and bilirubin-induced retinal degeneration.

Patients with hepatic failure are often accompanied by hepatic retinopathy, but the cellular and molecular mechanisms underlying the hepatic retinopathy remain unclear. In this study, we investigated how liver failure leads to hepatic retinopathy using bile duct ligation (BDL) rats as a cholestasis animal model. Light-dark box test was used to assess sensitivity to light, indexed as visual acuity. On D28 post-BDL, rats were subjected to light-dark box test and blood samples were collected for biochemical analyses. The rats then were euthanized. Liver, spleen and both side of eye were quickly harvested. We showed that BDL impaired rat sensitivity to light, significantly decreased the thickness of inner nuclear layer (INL), outer nuclear layer (ONL) and total retina, as well as the retinal cell numbers in ONL and ganglion cell layer (GCL). The expression of rhodopsin (RHO), brn-3a and GPX4 was significantly decreased in retina of BDL rats, whereas the expression of cleaved caspase 3, 8, 9, bax/bcl-2, RIP1, GFAP, and iba-1, as well as TUNEL-positive cells were significantly increased. In cultured retinal explant, we found that NH4Cl (0.2, 1, 5 mM) concentration-dependently impaired activity of retinal explant, decreased thickness of INL and ONL, downregulated expression of brn-3a, RHO and GFAP, increased expression of cl-caspase 3 and TUNEL-positive cell numbers, with NH4Cl (5 mM) almost completely disrupting the structure of the cultured retina; bilirubin (1 μM) significantly upregulated GFAP expression, whereas high level (10 μM) of bilirubin downregulated expression of GFAP. We further demonstrated in vivo that hyperammonemia impaired rat sensitivity to light, decreased thickness of INL and ONL, downregulated expression of RHO, brn-3a, GFAP and increased expression of cl-caspase 3; hyperbilirubinemia impaired rat sensitivity to light, upregulated expression of GFAP and iba-1. In conclusion, BDL impaired rat visual acuity due to the elevated levels of ammonia and bilirubin. Ammonia induced loss of retinal ganglion cells and rod photoreceptor cells via apoptosis-mediated cell death. Bilirubin impaired retinal function via activating microglia and Müller cells.

Analgesic Effect of Human Placenta Hydrolysate on CFA-Induced Inflammatory Pain in Mice.

To evaluate the efficacy of human placenta hydrolysate (HPH) in a mice model of CFA-induced inflammatory pain. TNF-α, IL-1β, and IL-6 are key pro-inflammatory cytokine factors for relieving inflammatory pain. Therefore, this study investigates whether HPH suppresses CFA-induced pain and attenuates the inflammatory process by regulating cytokines. In addition, the relationship between neuropathic pain and HPH was established by staining GFAP and Iba-1 in mice spinal cord tissues. This study was conducted for a total of day 28, and inflammatory pain was induced in mice by injecting CFA into the right paw at day 0 and day 14, respectively. 100 μL of 20% glucose and polydeoxyribonucleotide (PDRN) and 100, 200, and 300 μL of HPH were administered intraperitoneally twice a week. In the CFA-induced group, cold and mechanical allodynia and pro-inflammatory cytokine factors in the spinal cord and plantar tissue were significantly increased. The five groups of drugs evenly reduced pain and gene expression of inflammatory factors, and particularly excellent effects were confirmed in the HPH 200 and 300 groups. Meanwhile, the expression of GFAP and Iba-1 in the spinal cord was increased by CFA administration but decreased by HPH administration, which was confirmed to suppress damage to peripheral ganglia. The present study suggests that HPH attenuates CFA-induced inflammatory pain through inhibition of pro-inflammatory cytokine factors and protection of peripheral nerves.

Neuroprotection of isoorientin against microglia activation induced by lipopolysaccharide via regulating GSK3β, NF-κb and Nrf2/HO-1 pathways

Background: Isoorientin (ISO), a flavone C-glycoside, is a glycogen synthase kinase 3β (GSK3β) substrate-competitive inhibitor. ISO has potential in treatment of Alzheimer’s disease (AD). An excessive activation of GSK3β can lead to neuroinflammation causing neuronal damage. Microglia cells, as resident immune cells of the central nervous system, mediate neuroinflammation. Here, we studied the effects of ISO on microglial activation to alleviate neuroinflammation. Methods: Effects of ISO were observed upon the stimulation of mouse microglia BV2 or SIM-A9 cells by lipopolysaccharide (LPS). Lithium chloride (LiCl) was the positive control as a GSK3β inhibitor. The release of TNF-α and NO were analyzed by ELISA and Griess assays, while expressions of COX-2, Iba-1, BDNF, GSK3β, NF-κB p65, IκB, Nrf2 and HO-1 were detected by Western blotting. In the co-culture model of SIM-A9 cells and differentiated SH-SY5Y human neuroblastoma cells, effects of ISO on microglia-mediated neuronal damage were evaluated with the MTS assay. Results: ISO significantly inhibited the production of TNF-α (p < 0.01), NO (p < 0.001) and the expression of COX-2 (p < 0.01) and Iba-1 (p < 0.05) induced by LPS, and increased BDNF. The cell viability of SH-SY5Y was inhibited by LPS in the co-culture, which was prevented by ISO pretreatment. ISO increased the expression of p-GSK3β (Ser9), IκB and HO-1 in the cytoplasm, decreased NF-κB p65 and increased Nrf2 in the nucleus compared with the LPS group. Conclusion: ISO attenuated the activation of microglia through regulating the GSK3β, NF-κB and Nrf2/HO-1 signaling pathways to exert neuroprotection.

Immune-mediated impairment of tonic immobility defensive behavior in an experimental model of colonic inflammation.

Ulcerative colitis has been associated with psychological distress and an aberrant immune response. The immunomodulatory role of systemic cytokines produced during experimental intestinal inflammation in tonic immobility (TI) defensive behavior remains unknown. The present study characterized the TI defensive behavior of guinea pigs subjected to colitis induction at the acute stage and after recovery from intestinal mucosa injury. Moreover, we investigated whether inflammatory mediators (tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-8, IL-10, and prostaglandins) act on the mesencephalic nucleus, periaqueductal gray matter (PAG). Colitis was induced in guinea pigs by intrarectal administration of acetic acid. The TI defensive behavior, histology, cytokine production, and expression of c-FOS, IBA-1, and cyclooxygenase (COX)-2 in PAG were evaluated. Colitis reduced the duration of TI episodes from the first day, persisting throughout the 7-day experimental period. Neuronal c-FOS immunoreactivity was augmented in both columns of the PAG (ventrolateral (vlPAG) and dorsal), but there were no changes in IBA-1 expression. Dexamethasone, infliximab, and parecoxib treatments increased the duration of TI episodes, suggesting a modulatory role of peripheral inflammatory mediators in this behavior. Immunoneutralization of TNF-α, IL-1β, and IL-8 in the vlPAG reversed all effects produced by colitis. In contrast, IL-10 neutralization further reduced the duration of TI episodes. Our results reveal that peripherally produced inflammatory mediators during colitis may modulate neuronal functioning in mesencephalic structures such as vlPAG.

Antidepressant-like effect of riparin I and riparin II against CUMS-induced neuroinflammation via astrocytes and microglia modulation in mice.

Depression is a common mood disorder and many patients do not respond to conventional pharmacotherapy or experience a variety of adverse effects. This work proposed that riparin I (RIP I) and riparin II (RIP II) present neuroprotective effects through modulation of astrocytes and microglia, resulting in the reversal of depressive-like behaviors. To verify our hypothesis and clarify the pathways underlying the effect of RIP I and RIP II on neuroinflammation, we used the chronic unpredictable mild stress (CUMS) depression model in mice. Male Swiss mice were exposed to stressors for 28 days. From 15 th to the 22 nd day, the animals received RIP I or RIP II (50 mg/kg) or fluoxetine (FLU, 10 mg/kg) or vehicle, by gavage. On the 29 th day, behavioral tests were performed. Expressions of microglia (ionized calcium-binding adaptor molecule-1 - Iba-1) and astrocyte (glial fibrillary acidic protein - GFAP) markers and levels of cytokines tumor necrosis factor alfa (TNF-α) and interleukin 1 beta (IL-1β) were measured in the hippocampus. CUMS induced depressive-like behaviors and cognitive impairment, high TNF-α and IL-1β levels, decreased GFAP, and increased Iba-1 expressions. RIP I and RIP II reversed these alterations. These results contribute to the understanding the mechanisms underlying the antidepressant effect of RIP I and RIP II, which may be related to neuroinflammatory suppression.

Reduced voluntary wheel running behaviour in Kiss1r knockout mice

Kisspeptin and its receptor, Kiss1r, are novel players in the central balance of energy intake and expenditure. Recent evidence also indicates that kisspeptin signalling is important in thermoregulation and generation of the circadian rhythm. We used global Kiss1r knockout mice (Kiss1r KO), which are hypogonadal and develop obesity, to determine the impact of kisspeptin on circadian related behaviour. Voluntary wheel running was examined in Kiss1r KO and wild-type (WT) mice, using gonad intact and gonadectomised (GDX) mice to account for the effects of kisspeptin on gonadal sex steroids. Intact male and female Kiss1r KO mice covered only 10% and 30% of the distance travelled each day by their respective WT controls. In all mice, most of the running activity occurred during the dark phase. GDX WT mice ran significantly less during dark periods than the intact WT. GDX Kiss1r KO male mice ran significantly less than the GDX WT male mice, but the decrease was attenuated compared to intact mice. There was no difference between the female GDX Kiss1r KO and GDX WT. In contrast to the obese phenotype that develops in Kiss1r KO mice, body mass at the end of the study was significantly lower in the GDX Kiss1r KO than it was in the GDX WT mice. The difference in wheel running activity was not associated with any histological change in WAT, BAT, or muscle diameter. No difference in immunohistochemistry expression was seen in lateral hypothalamic orexin neurons or dopamine neurons in the ventral tegmental area / substantia nigra. We observed increased Iba1 expression (activation of microglia) in the arcuate nucleus of male Kiss1r KO mice. Overall, the circadian locomotor activity in male Kiss1r KO mice appears dependent on kisspeptin signalling and the obese phenotype does not develop in Kiss1r KO mice when they engage in voluntary activity.

Hsp60 deletion in cholinergic neurons: Impact on neuroinflammation and memory

Cholinergic circuit defects have been linked to various neurological abnormalities, yet the precise mechanisms underlying the impact of cholinergic signaling on cognitive functions, particularly in the context of neuroinflammation-associated, remain poorly understood. Similarly, while the dopamine receptor (D2R) has been implicated in the pausing of cholinergic interneurons (CIN), its relationship with behavior remains inadequately elucidated. In this study, we aimed to investigate whether D2R plays a role in the regulation of fear and memory in the Hsp60 knockout condition, given the non-canonical involvement of Hsp60 in inflammation. Using a CRE-floxed system, we selectively generated cholinergic neurons specific to Hsp60 knockout mice and subjected them to memory tests. Our results revealed a significant increase in freezing levels during recall and contextual tests in Hsp60-deprived mice. We also observed dysregulation of neurotransmitters and D2R in the hippocampus of Hsp60 knockout mice, along with enhanced impairments in cytokine levels and synaptic protein dysregulations. These changes were accompanied by alterations in PI3K/eIF4E/Jak/ERK/CREB signaling pathways. Notably, D2R agonism via Quinpirole led to a decrease in freezing levels during recall and contextual tests, alongside an increase in IBA-1 expression and improvements in inflammatory response-linked signaling pathways, including JAK/STAT/P38/JNK impairments. Given that these pathways are well-known downstream signaling cascades of D2R, our findings suggest that D2R signaling may contribute to the neuroinflammation induced by Hsp60 deprivation, potentially exacerbating memory impairments.

The GLP-1 medicines semaglutide and tirzepatide do not alter disease-related pathology, behaviour or cognitive function in 5XFAD and APP/PS1 mice

ObjectiveThe development of glucagon-like peptide-1 receptor (GLP-1R) agonists for the treatment of type 2 diabetes and obesity has been accompanied by evidence for anti-inflammatory and cytoprotective actions in the heart, blood vessels, kidney, and brain. Whether GLP-1R agonists might be useful clinically for attenuating deterioration of cognitive dysfunction and reducing the progression of Alzheimer's disease remains uncertain. MethodsHere we evaluated the actions of semaglutide and tirzepatide, clinically distinct GLP-1 medicines, in two mouse models of neurodegeneration. ResultsSemaglutide reduced body weight and improved glucose tolerance in 12-month-old male and female 5XFAD and APP/PS1 mice, consistent with pharmacological engagement of the GLP-1R. Nevertheless, amyloid plaque density was not different in the cerebral cortex, hippocampus, or subiculum of semaglutide-treated 12-month-old 5XFAD and APP/PS1 mice. IBA1 and GFAP expression were increased in the hippocampus of 5XFAD and APP/PS1 mice but were not reduced by semaglutide. Moreover, parameters of neurobehavioral and cognitive function evaluated using Open Field testing or the Morris water maze were not improved following treatment with semaglutide. To explore whether incretin therapies might be more effective in younger mice, we studied semaglutide and tirzepatide action in 6-month-old male and female 5XFAD mice. Neither semaglutide nor tirzepatide modified the extent of plaque accumulation, hippocampal IBA1+ or GFAP+ cells, or parameters of neurobehavioral testing, despite improving glucose tolerance and reducing body weight. mRNA biomarkers of inflammation and neurodegeneration were increased in the hippocampus of male and female 5XFAD mice but were not reduced after treatment with semaglutide or tirzepatide. ConclusionsCollectively, these findings reveal preservation of the metabolic actions of two GLP-1 medicines, semaglutide and tirzepatide, yet inability to detect improvement in structural and functional parameters of neurodegeneration in two mouse models of Alzheimer's disease.

Exosomal miRNA-21 derived from umbilical cord mesenchymal stem cells inhibits microglial overactivation to counteract nerve damage.

Traumatic brain injury (TBI) is a major cause of neurological disability, and current treatments have limited effectiveness. Recent studies have emphasized the potential of exosomes derived from umbilical cord mesenchymal stem cells (UC-MSCs-Exo) in TBI treatment, but the molecular mechanisms underlying their therapeutic effects are not fully understood. In this study, UC-MSCs-Exo was isolated using ultracentrifugation and intraventricularly injected to TBI rat model. The neurofunctional motor function of the rats was evaluated using the modified neurological severity score (mNSS), and the activation of microglia was assessed through immunofluorescence detection of IBA1 expression levels. Additionally, we established an in vitro neuroinflammatory model using BV2 microglia to investigate the effects of UC-MSCs-Exo and miRNA-21. Our findings indicate that UC-MSCs-Exo promote neurological recovery in TBI rats and inhibit excessive microglia activation. Furthermore, UC-MSCs-Exo highly expresses miRNA-21 and inhibited the proliferation, migration, and release of inflammatory mediators of BV2 microglia by transporting miRNA-21. The present study suggests that the promotion of neurological recovery in TBI rats by UC-MSCs-Exo may be attributed to the inhibition of excessive microglia activation through miRNA-21.

Ethyl acetate extract of Nymphaea candida Presl: A potential anti-depressant and neuroprotective treatment strategy

Nymphaea candida Presl (NC), traditionally used in medicine for heat syndrome-related ailments, possesses antioxidative, anti-inflammatory, hepatoprotective, and neuroprotective properties. This research investigates the antidepressant and neuroprotective effects and mechanisms of Nymphaea candida Presl ethyl acetate (NCEA). Primary components of NCEA were identified as phenolic acids and flavonoids through UPLC-MS/MS analysis. The depression mouse model was induced via intracerebroventricular injection of Lipopolysaccharide (LPS), followed by oral administration of fluoxetine and NCEA for one week. Biochemical assays and HE staining confirmed NCEA's non-toxicity and protective effects on the liver and lungs. NCEA administration mitigated LPS-induced depressive behaviors, decreased IL-1β, TNF-α levels in the hippocampus, suppressed microglial activation, reduced Iba-1 expression, and increased NA, brain-derived neurotrophic factor (BDNF), and dendritic spine density in the hippocampus. Furthermore, NCEA enhanced cell viability in a CORT-induced PC12 cell model, decreased lactate dehydrogenase (LDH) release rate, total superoxide dismutase (SOD) inhibition rate, intracellular nitric oxide (NO) release, and reduced reactive oxygen species (ROS) production. Our research findings suggest that NCEA exhibits significant antidepressant effects, which may be attributed to its reduction of neuroinflammation, improvement in neurotransmitter levels, neuronal protection, and antioxidative stress properties.

Acute ocular hypertension in the living human eye: Model description and initial cellular responses to elevated intraocular pressure

This initial methods study presents the initial immunohistochemical and transcriptomic changes in the optic nerve head and retina from three research-consented brain-dead organ donors following prolonged and transient intraocular pressure (IOP) elevation. In this initial study, research-consented brain-dead organ donors were exposed to unilateral elevation of IOP for 7.5 h (Donor 1), 30 h (Donor 2), and 1 h (Donor 3) prior to organ procurement. Optic nerve tissue and retinal tissue was obtained following organ procurement for immunohistological and transcriptomic analysis.Optic nerve sections in Donor 1 exposed to 7.5-hours of unilateral sub-ischemic IOP elevation demonstrated higher levels of protein expression of the astrocytic marker, glial fibrillary acidic protein (GFAP), within the lamina cribrosa with greatest expression inferior temporally in the treated eye compared to control. Spatial transcriptomic analysis performed on optic nerve head tissues from Donor 2 exposed to 30 h of unilateral IOP elevation demonstrated differential transcription of mRNA across laminar and scleral regions. Immunohistochemistry of retinal sections from Donor 2 exhibited higher GFAP and IBA1 expression in the treated eye compared with control, but this was not observed in Donor 3, which was exposed to only 1-hour of IOP elevation. While there were no differences in GFAP protein expression in the retina following the 1-hour IOP elevation in Donor 3, there were higher levels of transcription of GFAP in the inner nuclear layer, and CD44 in the retinal ganglion cell layer, indicative of astrocytic and Müller glial reactivity as well as an early inflammatory response, respectively.We found that transcriptomic differences can be observed across treated and control eyes following unilateral elevation of IOP in brain dead organ donors. The continued development of this model affords the unique opportunity to define the acute mechanotranscriptomic response of the optic nerve head, evaluate the injury and repair mechanisms in the retina in response to IOP elevation, and enable correlation of in vivo imaging and functional testing with ex vivo cellular responses for the first time in the living human eye.

Tet1-mediated 5hmC regulates hippocampal neuroinflammation via wnt signaling as a novel mechanism in obstructive sleep apnoea leads to cognitive deficit

BackgroundObstructive sleep apnoea (OSA) is a sleep-disordered breathing characterized by intermittent hypoxia (IH) that may cause cognitive dysfunction. However, the impact of IH on molecular processes involved in cognitive function remains unclear.MethodsC57BL / 6 J mice were exposed to either normoxia (control) or IH for 6 weeks. DNA hydroxymethylation was quantified by hydroxymethylated DNA immunoprecipitation (hMeDIP) sequencing. ten-eleven translocation 1 (Tet1) was knocked down by lentivirus. Specifically, cognitive function was assessed by behavioral experiments, pathological features were assessed by HE staining, the hippocampal DNA hydroxymethylation was examined by DNA dot blot and immunohistochemical staining, while the Wnt signaling pathway and its downstream effects were studied using qRT-PCR, immunofluorescence staining, and Luminex liquid suspension chip analysis.ResultsIH mice showed pathological changes and cognitive dysfunction in the hippocampus. Compared with the control group, IH mice exhibited global DNA hydroxylmethylation in the hippocampus, and the expression of three hydroxylmethylases increased significantly. The Wnt signaling pathway was activated, and the mRNA and 5hmC levels of Wnt3a, Ccnd2, and Prickle2 were significantly up-regulated. Further caused downstream neurogenesis abnormalities and neuroinflammatory activation, manifested as increased expression of IBA1 (a marker of microglia), GFAP (a marker of astrocytes), and DCX (a marker of immature neurons), as well as a range of inflammatory cytokines (e.g. TNFa, IL3, IL9, and IL17A). After Tet1 knocked down, the above indicators return to normal.ConclusionActivation of Wnt signaling pathway by hippocampal Tet1 is associated with cognitive dysfunction induced by IH.Graphical

Effects of apelin on neonatal brain neurogenesis in L-NAME-induced maternal preeclampsia

The aim of this study was to investigate the possible protective effects of apelin, which is known to have antioxidant and anti-inflammatory effects, on changes in neurogenesis in newborns of pregnant rats with L-NAME-induced preeclampsia. Wistar albino female rats were divided into four experimental groups: Control, Apelin, Preeclampsia and Preeclampsia + Apelin. Blood pressure was measured on the 5th, 11th and 17th days of gestation, urine protein was analyzed from urine samples collected for 24 h on the 6th, 12th and 18th days and serum creatinine was analyzed from serum samples. Maternal kidney and placenta tissues were obtained to establish the preeclampsia model, and neonatal brain tissues including the cortex, hippocampus and cerebellum regions were obtained to investigate neurogenesis and examined by histological and immunohistochemical methods. The number of newborns, body weight and brain weight of the newborns were measured. eNOS, IL-10, nNOS and NO levels in the brain analyzed via ELISA. Mean arterial pressure, urine protein and serum creatinine increased in the preeclampsia. Newborn weight decreased in the Preeclampsia group, the values in the Preeclampsia + Apelin group were closer to the Control and Apelin groups. In the Preeclampsia group, edema and dilatation in the proximal and distal tubules of kidneys, perivillous fibrin deposition and increase in syncytial nodules of placenta were observed. VEGF immunoreactivity decreased and iNOS immunoreactivity increased in both kidney and placenta. In neonatal brain tissue examinations, cytotoxic edema accompanied by thinning of cortex, delayed migration and lower cell counts in the hippocampus, and increase in intercellular spaces and EGL thickening in the cerebellum were observed in the preeclampsia. Expression of NeuN, GFAP, MBP, IL-10, eNOS, nNOS and NO levels decreased, whereas expression of Iba-1 increased in the preeclampsia. In the Preeclampsia + Apelin group, these findings were similar to the Control and Apelin groups. Apelin administration was found to be beneficial for preventing the adverse consequences of preeclampsia, but further experimental and clinical studies are needed to better understand these effects.