Brain Tissue Levels Research Articles

Acute Low Dose Naltrexone Increases β-Endorphin and Promotes Neuronal Recovery Following Hypoxia-Ischemic Stroke in Type-2 Diabetic Mice.

Diabetic patients experience significant mortality and poor recovery following ischemic stroke. Our clinical and basic science studies demonstrate an overall immune suppression in the periphery of diabetic stroke patients, as well as within the central nervous system (CNS) of type-2 diabetic mice following hypoxia-ischemia (HI). Low doses of naltrexone (LDN) improved clinical outcomes in many autoimmune diseases by acting on opioid receptors to release β-endorphin which in turn balances inflammatory cytokines and modulates the opioid growth factor (OGF)-opioid growth factor receptor (OGFr) pathway. We hypothesized that in our model of diabetic mice, LDN treatment will induce the release of β-endorphin and improve CNS response by promoting neuronal recovery post HI. To test this hypothesis, we induced HI in 10week old male db/db and db/ + mice, collected tissue at 24 and 72h post HI, and measured OGF levels in plasma and brain tissue. The infarct size and number of OGF + neurons in the motor cortex, caudate and hippocampus (CA3) were measured. Following HI, db/db mice had significant increases in brain OGF expression, increased infarct size and neurological deficits, and loss of OGFr + neurons in several different brain regions. In the second experiment, we injected LDN (1mg/kg) intraperitoneally into db/db and db/ + mice at 4, 24, and 48h post HI, and collected brain tissue and blood at 72h. Acute LDN treatment increased β-endorphin and OGF levels in plasma and promoted neuronal recovery in db/db mice compared to phosphate buffer saline (PBS)-treated diabetic mice suggesting a protective or regenerative effect of LDN.

Roflumilast Protects against Neuroinflammatory Alterations in Brain Tissues of Lipopolysaccharide-induced Mice Model.

Microglial overactivation promotes the production of various second messengers and inflammatory markers in brain tissue, resulting in neuroinflammation and neurodegeneration, which may lead to cognitive decline. The cyclic nucleotides are one of the important second messengers involved in the regulation of neurogenesis, synaptic plasticity, and cognition. The levels of these cyclic nucleotides are maintained by phosphodiesterase enzyme isoforms, particularly PDE4B, in the brain. An imbalance between PDE4B levels and cyclic nucleotides may lead to aggravating neuroinflammation. Lipopolysaccharides (LPS) were administered intraperitoneally on alternate days for 7 days at a dose of 500 μg/kg in mice, which triggered systemic inflammation. This may lead to the activation of glial cells and may activate oxidative stress and neuroinflammatory markers in brain tissue. Furthermore, oral administration of roflumilast (0.1, 0.2, and 0.4 mg/kg) in this model ameliorated oxidative stress markers, neuroinflammation and improved neurobehavioral parameters in these animals. The detrimental effect of LPS increased oxidative stress, AChE enzyme levels, and decreased catalase levels in brain tissues, along with memory impairment in animals. Moreover, it also enhanced the activity and expression of the PDE4B enzyme, resulting in a decline in cyclic nucleotide levels. Furthermore, treatment with roflumilast improved the cognitive decline, decreased AChE enzyme level, and increased the catalase enzyme level. Roflumilast also reduced the PDE4B expression in a dose-dependent manner, which LPS up-regulated. Roflumilast has shown an anti-neuroinflammatory effect and reversed the cognitive decline in LPS-induced mice model.

High affinity of β-amyloid proteins to cerebral capillaries: implications in chronic lead exposure-induced neurotoxicity in rats

Lead (Pb) is a known environmental risk factor in the etiology of Alzheimer’s disease (AD). The existing reports suggest that Pb exposure increases beta-amyloid (Aβ) levels in brain tissues and cerebrospinal fluid (CSF) and facilitates the formation of amyloid plaques, which is a pathological hallmark for AD. Pb exposure has long been associated with cerebral vasculature injury. Yet it remained unclear if Pb exposure caused excessive Ab buildup in cerebral vasculature, which may damage the blood–brain barrier and cause abnormal Ab accumulation. This study was designed to investigate the impact of chronic Pb exposure on Aβ accumulation in cerebral capillary and the expression of low-density lipoprotein receptor protein-1 (LRP1), a critical Aβ transporter, in brain capillary and parenchyma. Sprague–Dawley rats received daily oral gavage at doses of 0, 14 (low-dose), and 27 (high-dose) mg Pb/kg as Pb acetate, 5 d/wk, for 4 or 8 wks. At the end of Pb exposure, a solution containing Aβ40 was infused into the brain via the cannulated internal carotid artery. Data by ELISA showed a strikingly high affinity of Ab to cerebral vasculature, which was approximately 7–14 times higher than that to the parenchymal fractions collected from control brains. Pb exposure further aggravated the Aβ accumulation in cerebral vasculature in a dose-dependent manner. Western blot analyses revealed that Pb exposure decreased LRP1 expression in cortical capillaries and hippocampal parenchyma. Immunohistochemistry (IHC) studies further revealed a disrupted distribution of LRP1 alongside hippocampal vasculature accompanied with a decreased expression in hippocampal neurons by Pb exposure. Taken together, the current study demonstrated that the cerebral vasculature naturally possessed a high affinity to Aβ present in circulating blood. Pb exposure significantly increased Aβ accumulation in cerebral vasculature; such an increased Aβ accumulation was due partly to the diminished expression of LRP1 in response to Pb in tested brain regions. Perceivably, Pb-facilitated Ab aggravation in cerebral vasculature may contribute to Pb-associated amyloid alterations.

Dihydromyricetin suppresses inflammatory injury in microglial cells to improve neurological behaviors of Alzheimer's disease mice via the TLR4/MD2 signal.

We analyzed the role and mechanism of dihydromyricetin (DHM) in suppressing inflammatory injury in microglial cells via targeting MD2. In vitro, BV2 cells were used as the objects of study to induce inflammatory injury with LPS+ATP, then the cell apoptosis level was identified, inflammatory factor levels were measured by ELISA, TLR4 and MD2 were stained with fluorescence staining, and protein expression was determined using Western-blot (WB) assay. Afterwards, MD2 expression was knocked down n BV2 cells to construct the BV2-MD2-/- cell line, so as to detect the role of DHM on BV2-MD2-/-. Moreover, the binding of DHM to MD2 was analyzed via mall molecule-protein docking and pull-down assays. In-vivo, wild-type (WT) C67BL/6 mice and APP/PS1 (AD) mice were used as the objects of study, which were intervened with DHM to detect the changes in mouse cognition. In addition, the pathological changes of brain tissues were analyzed with H&E staining. In addition, the inflammatory factor and protein levels in brain tissues were also detected. DHM suppressed inflammatory injury in BV2 cells, reduced the cell apoptosis rate and inflammatory factor levels, and suppressed the level of TLR4 and MD2. After MD2 knockdown, DHM was unable to further suppress BV2 cell injury. Results of small molecule-protein docking and pull-down assays suggested that DHM bound to MD2 to suppress the formation of TLR4 complex. In AD mice, DHM improved the cognitive disorder in mice, suppressed inflammatory injury in brain tissues and lowered the expression of TLR4 protein. DHM targeted MD2 to suppress the formation of TLR4 protein complex, thereby suppressing inflammatory injury in microglial cells and improving the cognition in AD mice.

Protective Alzheimer's disease-associated APP A673T variant predominantly decreases sAPPβ levels in cerebrospinal fluid and 2D/3D cell culture models

The rare A673T variant was the first variant found within the amyloid precursor protein (APP) gene conferring protection against Alzheimer's disease (AD). Thereafter, different studies have discovered that the carriers of the APP A673T variant show reduced levels of amyloid beta (Aβ) in the plasma and better cognitive performance at high age. Here, we analyzed cerebrospinal fluid (CSF) and plasma of APP A673T carriers and control individuals using a mass spectrometry-based proteomics approach to identify differentially regulated targets in an unbiased manner. Furthermore, the APP A673T variant was introduced into 2D and 3D neuronal cell culture models together with the pathogenic APP Swedish and London mutations. Consequently, we now report for the first time the protective effects of the APP A673T variant against AD-related alterations in the CSF, plasma, and brain biopsy samples from the frontal cortex. The CSF levels of soluble APPβ (sAPPβ) and Aβ42 were significantly decreased on average 9–26% among three APP A673T carriers as compared to three well-matched controls not carrying the protective variant. Consistent with these CSF findings, immunohistochemical assessment of cortical biopsy samples from the same APP A673T carriers did not reveal Aβ, phospho-tau, or p62 pathologies. We identified differentially regulated targets involved in protein phosphorylation, inflammation, and mitochondrial function in the CSF and plasma samples of APP A673T carriers. Some of the identified targets showed inverse levels in AD brain tissue with respect to increased AD-associated neurofibrillary pathology. In 2D and 3D neuronal cell culture models expressing APP with the Swedish and London mutations, the introduction of the APP A673T variant resulted in lower sAPPβ levels. Concomitantly, the levels of sAPPα were increased, while decreased levels of CTFβ and Aβ42 were detected in some of these models. Our findings emphasize the important role of APP-derived peptides in the pathogenesis of AD and demonstrate the effectiveness of the protective APP A673T variant to shift APP processing towards the non-amyloidogenic pathway in vitro even in the presence of two pathogenic mutations.

Rabies virus infection is associated with variations in calbindin D-28K and calretinin mRNA expression levels in mouse brain tissue.

Rabies virus (RABV) infection leads to a fatal neurological outcome in humans and animals and is associated with major alterations in cellular gene expression. In this study, we describe the effects of RABV infection on the mRNA expression levels of two genes, encoding the Ca2+-binding proteins (Ca-BPs) calbindin D-28K (Calb1) and calretinin (Calb2), in the brains of BALB/c mice. Sixty 4-week-old mice were divided into two test groups and one control group. Mice were inoculated intramuscularly with either a street rabies virus (SRV) strain or a challenge virus standard (CVS-11) strain and sacrificed at 3-day intervals up to day 18 postinfection. A direct fluorescent antibody test (DFAT) was used to verify the presence of RABV antigen in brain tissues, and real-time quantitative PCR (RT-PCR) was used to assess gene expression. Infection with both RABV strains resulted in significant (p < 0.05) increases in Calb1 and Calb2 expression in the test animals when compared with the controls at various time points in the study. Correlation analysis indicated very weak insignificant (p > 0.05) negative and positive relationships, respectively, between Calb1 expression (r = -0.04) and Calb2 expression (r = 0.08) with viral load (CVS-11 strain). Insignificant (p > 0.05) relationships were also observed Calb1 expression (r = -0.28) and Calb2 expression (r = 0.06) and viral load for the SRV strain.The observed alterations in Calb1 and Calb2 expression in this study indicate possible impairments in neuronal Ca2+ buffering and Ca2+ homeostasis as a result of RABV infection and, consequently, possible involvement of calbindin-D28K and calretinin in the neuropathogenesis of rabies.

Abstract 348: Elucidation of SUMOylation machinery in human cancer cells and naked mole-rat tissues

Abstract Background: SUMOylation is a post-translational modification where small ubiquitin-like modifier (SUMO) proteins are conjugated to lysine residues of target proteins. SUMO proteins exist in all eukaryotes and participate in a catalytic cycle, which includes maturation, activation, conjugation, ligation, and de-modification. SUMOylation is known to regulate numerous molecular regulatory mechanisms such as: chromatin remodeling, DNA repair, immune responses, cell cycle progression, apoptosis, and the intracellular signal transduction. SUMOylation dysregulation is known to promote several diseases, including cancer cell survival. The unique traits of phenotypic and molecular adaptations found in naked mole rats (NMR) suggest high stability and effective functioning of the molecular machinery that counteract damage accumulation in its genome. NMR lifespan can reach up to 32 years and acquires a very efficient mechanism of resistance to cancer. This study aims to investigate the regulation of SUMO machinery between human cancer cells breast (MCF-7), colorectal (DLD-1), and neuroblastoma (SH-SY5Y)) and NMR brain and intestinal tissues, in order to find novel targets for cancer treatment. Results: The pairwise alignment identified the similarity of both SUMO genes and proteins including SUMO1, SUMO2/3, and SUMO components of Sentrin-specific protease isoforms (SENP 1-7), activation (SAE1 and Uba2), conjugation (Ubc9), and ligation isoforms (PIAS1-4) between NMR and human. In addition, qRT-PCR data revealed low expression of SUMO components at the mRNA level in NMR brain and intestinal tissues compared to MCF-7, DLD-1, and SH-SY5Y cell lines. On the contrary, PIAS4 expression is significantly higher in the NMR tissues compared to cancer cell lines. Protein analysis via Western blotting performed on MCF-7, DLD-1, and SH-SY5Y cell lines revealed similar levels to mRNA compared to NMR tissue. Ongoing studies are focusing on several functional assays to investigate effects of hUBE2I, hSENP1, and Myc/hPIAS4 effects on cytotoxicity and signaling properties of the cancer cells using techniques such as Microculture Tetrazolium (MTT), migration, invasion, and colony formation. The effect on cytotoxicity is also analyzed in relevance to clinical used treatments such as Doxorubicin in MCF-7, 5-Fluorouracil for DLD-1 and Methotrexate in SH-SY5Y. Conclusion: Expression analysis of SUMOylation machinery revealed lower expression of mRNA levels for SUMO components was observed in NMR tissues compared to all human cancer cells. However, PIAS4 expression was significantly higher in the NMR tissues compared to cancer cell lines. This data revealed important differences in NMR SUMOylation machinery (such as UBE2I, SENP1 and PIAS4) which provides a future therapeutic avenue to treat cancer. Citation Format: Mohammed Abdullah Mohammed Salih, Ritchie Williamson, Sriharsha Kantamneni. Elucidation of SUMOylation machinery in human cancer cells and naked mole-rat tissues [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 348.

Probiotic Fermentation of Kelp Enzymatic Hydrolysate Promoted its Anti-Aging Activity in D-Galactose-Induced Aging Mice by Modulating Gut Microbiota.

To investigate anti-aging effects of probiotic-fermented kelp enzymatic hydrolysate culture (KMF), probiotic-fermented kelp enzymatic hydrolysate supernatant (KMFS), and probiotic-fermented kelp enzymatic hydrolysate bacteria suspension (KMFP) in D-galactose-induced aging mice. The study uses a probiotic-mixture of Lactobacillus reuteri, Pediococcus pentosaceus, and Lactobacillus acidophilus strains for kelp fermentation. KMF, KMFS, and KMFP prevent D-galactose-induced elevation of malondialdehyde levels in serum and brain tissue of aging mice, and they increase superoxide dismutase and catalase levels and total antioxidant capacity. Furthermore, they improve the cell structure of mouse brain, liver, and intestinal tissue. Compared with the model control group, the KMF, KMFS, and KMFP treatments regulate mRNA and protein levels of genes associated with aging, the concentrations of acetic acid, propionic acid, and butyric acid in the three treatment groups are more than 1.4-, 1.3-, and 1.2-fold increased, respectively. Furthermore, the treatments affect the gut microbiota community structures. These results suggest that KMF, KMFS, and KMFP can modulate gut microbiota imbalances and positively affect aging-related genes to achieve anti-aging effects.

Protective effects of a novel glycogen phosphorylase inhibitor against cerebral ischemia-reperfusion injury in mice.

Aim: To evaluate the effects of a novel glycogen phosphorylase inhibitor (NGPI) on cerebral ischemia-reperfusion injury (CIRI). Methods: Cerebral ischemia was induced in mice using a modified bilateral common carotid artery ligation model. To assess the effects of NGPI against CIRI, mice which had been administered with different doses of NGPI (1.25, 2.5, 5mg/kg/day) for 7days before the injury were evaluated for infarct volume, the apoptosis level of brain tissue, integrity of brain tissue and oxidative stress level. Results: NGPI effectively improved the infarct area, apoptosis of neurons, integrity of brain tissue and oxidative stress level of mice with CIRI. Conclusion: NGPI could effectively improve CIRI and deserves further study.

Angelicin Alleviates Maternal Isoflurane Exposure-Induced Offspring Cognitive Defects Through the Carbonic Anhydrase 4/Aquaporin-4 Pathway.

An increasing number of studies reveal the deleterious effects of isoflurane (Iso) exposure during pregnancy on offspring cognition. However, no effective therapeutic strategy for Iso-induced deleterious effects has been well developed. Angelicin exerts an anti-inflammatory effect on neurons and glial cells. This study investigated the roles and mechanism of action of angelicin in Iso-induced neurotoxicity in vitro and in vivo. After exposing C57BL/6J mice on embryonic day 15 (E15) to Iso for 3 and 6h, respectively, neonatal mice on embryonic day 18 (E18) displayed obvious anesthetic neurotoxicity, which was revealed by the elevation of cerebral inflammatory factors and blood-brain barrier (BBB) permeability and cognitive dysfunction in mice. Angelicin treatment could not only significantly reduce the Iso-induced embryonic inflammation and BBB disruption but also improve the cognitive dysfunction of offspring mice. Iso exposure resulted in an increase of carbonic anhydrase (CA) 4 and aquaporin-4 (AQP4) expression at both mRNA and protein levels in vascular endothelial cells and mouse brain tissue collected from neonatal mice on E18. Remarkably, the Iso-induced upregulation of CA4 and AQP4 expression could be partially reversed by angelicin treatment. Moreover, GSK1016790A, an AQP4 agonist, was used to confirm the role of AQP4 in the protective effect of angelicin. Results showed that GSK1016790A abolished the therapeutic effect of angelicin on Iso-induced inflammation and BBB disruption in the embryonic brain and on the cognitive function of offspring mice. In conclusion, angelicin may serve as a potential therapeutic for Iso-induced neurotoxicity in neonatal mice by regulating the CA4/AQP4 pathway.

The role of microRNAs in depression.

Major depressive disorder (MDD) is a psychiatric disorder with increasing prevalence worldwide. It is a leading cause of disability and suicide, severely affecting physical and mental health. However, the study of depression remains at an exploratory stage in terms of diagnostics and treatment due to the complexity of its pathogenesis. MicroRNAs are endogenous short-stranded non-coding RNAs capable of binding to the 3'untranslated region of mRNAs. Because of their ability to repress translation process of genes and are found at high levels in brain tissues, investigation of their role in depression has gradually increased recently. This article summarizes recent research progress on the relationship between microRNAs and depression. The microRNAs play a regulatory role in the pathophysiology of depression, involving dysregulation of monoamines, abnormalities in neuroplasticity and neurogenesis, hyperactivity of the HPA axis, and dysregulation of inflammatory responses. These microRNAs might provide new clue for the diagnosis and treatment of MDD, and the development of antidepressant drugs.

Sevoflurane preconditioning improves neuroinflammation in cerebral ischemia/reperfusion induced rats through ROS-NLRP3 pathway

AimWe aimed to study the influence of sevoflurane on the nucleotide-binding domain and Leucine-rich repeat protein 3 (NLRP3) pathways in rats with cerebral ischemia/reperfusion (I/R) injury. MethodsSixty Sprague–Dawley rats were equally divided into five groups randomly: sham-operated, cerebral I/R, sevoflurane (Sevo), NLRP3 inhibitor-treated (MCC950), and sevoflurane and NLRP3 inducer-treated groups. Rats’ neurological functions were assessed using Longa scoring after 24 h of reperfusion, after which they were sacrificed, and cerebral infarction area was determined by triphenyl tetrazolium chloride staining. Pathological changes in damaged portions were assessed using hematoxylin-eosin and Nissl staining, and cell apoptosis was detected by terminal-deoxynucleotidyl transferase-mediated nick end labeling staining. Interleukin 1 beta (IL-1β), tumor necrosis factor α (TNF-α), interleukin-6 (IL-6), interleukin-18 (IL-18), malondialdehyde (MDA), and superoxide dismutase (SOD) levels in brain tissues were determined using enzyme-linked immunosorbent assay. Reactive oxygen species (ROS) levels were analyzed using a ROS assay kit. Protein levels of NLRP3, caspase-1, and IL-1β were determined by western blot. ResultsNeurological function scores, cerebral infarction areas, and neuronal apoptosis index were decreased in the Sevo and MCC950 groups than in the I/R group. IL-1β, TNF-α, IL-6, IL-18, NLRP3, caspase-1, and IL-1β levels decreased in the Sevo and MCC950 groups (p < 0.05). ROS and MDA levels increased, but SOD levels increased in the Sevo and MCC950 groups than in the I/R group. NLPR3-inducer nigericin eliminated the protective effects of sevoflurane on cerebral I/R injury in rats. ConclusionSevoflurane could alleviate cerebral I/R-induced brain damage by inhibiting the ROS-NLRP3 pathway.

Effects of RF and ELF Radiation on Oxidative Stress of Brain Tissue and Plasma of Diabetic Rats

Objective: Exposure to Radio Frequency (RF) and Extremely Low Frequency (ELF) radiation is increasing steadily with the progress of technology and industrialization. The aim of this study was to investigate whether RF and ELF radiation are oxidative stress effects in the plasma and brain tissue of diabetic and non-diabetic rats. Methods: Experiment groups were designed as follows; C (control), S (sham), ELF (ELF radiation exposure), RF (RF radiation exposure), ELF+RF (ELF and RF radiation exposure), D-C (Diabetic Control), D-S (Diabetic Sham), D-ELF (Diabetic ELF), D-RF (Diabetic RF), D-ELF+RF (Diabetic ELF+RF). The experimental diabetes model was induced with a single dose of 65mg/kg streptozotocin (STZ). 2100 MHz RF and 50 Hz ELF radiation groups exposed for 1 month. Total nitric oxide (NOx), malondialdehyde (MDA) and total sulfhydryl groups (RSH) / glutathione (GSH) levels were measured in plasma and brain tissue. Results: RF + ELF radiation exposure caused an increase in NOx and MDA levels in plasma and brain tissue of diabetic and non-diabetic rats (p&amp;lt;0.05). Exposure to RF and RF + ELF radiation caused a decrease in plasma RSH / tissue GSH levels in non-diabetic rats (p&amp;lt;0.05). Conclusion: The most prominent effect was seen in the diabetic group with RF + ELF radiation exposure.

Electroacupuncture and human iPSC-derived small extracellular vesicles regulate the gut microbiota in ischemic stroke via the brain-gut axis.

Electroacupuncture (EA) and induced pluripotent stem cell (iPSC)-derived small extracellular vesicles (iPSC-EVs) have substantial beneficial effects on ischemic stroke. However, the detailed mechanisms remain unclear. Here, we explored the mechanisms underlying the regulation of EA and iPSC-EVs in the microbiome-gut-brain axis (MGBA) after ischemic stroke. Ischemic stroke mice (C57BL/6) were subjected to middle cerebral artery occlusion (MCAO) or Sham surgery. EA and iPSC-EVs treatments significantly improved neurological function and neuronal and intestinal tract injury, downregulated the levels of IL-17 expression and upregulated IL-10 levels in brain and colon tissue after cerebral ischemia-reperfusion. EA and iPSC-EVs treatments also modulated the microbiota composition and diversity as well as the differential distribution of species in the intestines of the mice after cerebral ischemia-reperfusion. Our results demonstrated that EA and iPSC-EVs treatments regulated intestinal immunity through MGBA regulation of intestinal microbes, reducing brain and colon damage following cerebral ischemia and positively impacting the outcomes of ischemic stroke. Our findings provide new insights into the application of EA combined with iPSC-EVs as a treatment for ischemic stroke.

5-Methylcytosine and 5-Hydroxymethylcytosine in Scrapie-Infected Sheep and Mouse Brain Tissues.

Scrapie is a neurodegenerative disorder belonging to the group of transmissible spongiform encephalopathies or prion diseases, which are caused by an infectious isoform of the innocuous cellular prion protein (PrPC) known as PrPSc. DNA methylation, one of the most studied epigenetic mechanisms, is essential for the proper functioning of the central nervous system. Recent findings point to possible involvement of DNA methylation in the pathogenesis of prion diseases, but there is still a lack of knowledge about the behavior of this epigenetic mechanism in such neurodegenerative disorders. Here, we evaluated by immunohistochemistry the 5-methylcytosine (5mC) and 5-hydroxymethylcytosine (5hmC) levels in sheep and mouse brain tissues infected with scrapie. Expression analysis of different gene coding for epigenetic regulatory enzymes (DNMT1, DNMT3A, DNMT3B, HDAC1, HDAC2, TET1, and TET2) was also carried out. A decrease in 5mC levels was observed in scrapie-affected sheep and mice compared to healthy animals, whereas 5hmC displayed opposite patterns between the two models, demonstrating a decrease in 5hmC in scrapie-infected sheep and an increase in preclinical mice. 5mC correlated with prion-related lesions in mice and sheep, but 5hmC was associated with prion lesions only in sheep. Differences in the expression changes of epigenetic regulatory genes were found between both disease models, being differentially expressed Dnmt3b, Hdac1, and Tet1 in mice and HDAC2 in sheep. Our results support the evidence that DNA methylation in both forms, 5mC and 5hmC, and its associated epigenetic enzymes, take part in the neurodegenerative course of prion diseases.

Knee osteoarthritis accelerates amyloid beta deposition and neurodegeneration in a mouse model of Alzheimer’s disease

Knee osteoarthritis (OA) is characterized by knee cartilage degeneration and secondary bone hyperplasia, resulting in pain, stiffness, and gait disturbance. The relationship between knee OA and neurodegenerative diseases is still unclear. This study used an Alzheimer’s disease (AD) mouse model to observe whether osteoarthritis accelerates dementia progression by analyzing brain histology and neuroinflammation. Knee OA was induced by destabilizing the medial meniscus (DMM) in control (WT) and AD (5xFAD) mice before pathological symptoms. Mouse knee joints were scanned with a micro-CT scanner. A sham operation was used as control. Motor and cognitive abilities were tested after OA induction. Neurodegeneration, β-amyloid plaque formation, and neuroinflammation were analyzed by immunostaining, Western blotting, and RT-PCR in brain tissues. Compared with sham controls, OA in AD mice increased inflammatory cytokine levels in brain tissues. Furthermore, OA significantly increased β-amyloid deposition and neuronal loss in AD mice compared to sham controls. In conclusion, knee OA accelerated amyloid plaque deposition and neurodegeneration in AD-OA mice, suggesting that OA is a risk factor for AD.

Effects of Gundelia tournefortii L. on biochemical parameters, antioxidant activities and DNA damage in a rat model of experimental obesity.

The present study was designed to investigate the effects of Gundelia tournefortii L. plant extract on different tissues in terms of DNA damage, biochemical and antioxidant parameter values in rats with high-calorie diets. With this aim, Wistar albino male rats were divided into 4 groups containing 6 rats each and the study was completed over 12 weeks duration. At the end of the implementation process over the 12 weeks, rats were sacrificed and blood and tissue samples were obtained. Analyses were performed on blood and tissue samples. According to results for DNA damage (8-OHdG), in brain tissue the OG2 group was significantly reduced compared to the NC group. For MDA results in liver tissue, OG1 and OG2 groups were determined to increase by a significant degree compared to the control group, while the OG2 group was also increased significantly compared to the obese group. In terms of the other parameters, comparison between the groups linked to consumption of a high calorie diet (HCD) and administration of Gundelia tournefortii L. in terms of antioxidant activities and serum samples obtained statistically significant results. Gundelia tournefortii L. plant extracts had effects that may be counted as positive on antioxidant parameter activity and were especially identified to improve DNA damage and MDA levels in brain tissues. Additionally, consumption of Gundelia tournefortii L. plant extract in the diet may have antiobesity effects; thus, it should be evaluated for use as an effective weight-loss method and as a new therapeutic agent targeting obesity.

Effect of selenium against doxorubicin-induced oxidative stress, inflammation, and apoptosis in the brain of rats: Role of TRPM2 channel

Doxorubicin (DOX) is widely used as an anticancer drug in humans' various solid and haematological tumours. Although many studies on the toxic effect of DOX are used in different organs, its impact on brain tissue has yet to be adequately studied. This study investigated the protective effect of selenium (Se) and the role of transient receptor potential melastatin‐2 (TRPM2) channel activation against brain damage caused by DOX administration. Sixty rats were randomly divided into the sham, dimethyl sulfoxide (DMSO), DOX, DOX + Se, DOX + N-(p-amylcinnamoyl) anthranilic acid (ACA), and DOX + Se + ACA groups. The reactive oxygen species (ROS), poly [ADP-ribose] polymerase 1 (PARP1), and TRPM2 channel levels in brain tissues were measured by ELISA. In addition, a histopathological examination was performed in the cerebral cortex and hippocampal areas, and the TRPM2 channel, NF-κB, and caspase-3 expression were determined immunohistochemically. The levels of ROS, PARP1 and TRPM2 channel in the DOX group were higher than in the sham and DMSO groups (P &lt; 0.05). However, these parameters were decreased in the in DOX+Se and DOX+ACA groups by the treatments of Se and ACA (P &lt; 0.05). Also, we determined that Se and ACA treatment decreased the NF-κB, caspase-3, and TRPM2 channel expression in the cerebral cortex and hippocampal areas in the DOX-induced rats. The data showed that Se and/or ACA administration together with DOX administration could be used as a protective agent against DOX-induced brain damage.

Impact of Crossbreeding Between Local and Foreign Strains on the Growth Traits and the Expression of Insulin-Like Growth Factor Genes on Their Chicks

Abstract: The aim of this work was to evaluate the impact of crossing pure Gimmizah or Bandara (local breeds) with pure Ross (a foreign breed) on growth rate, and the expression of IGF genes. Two local breeds, Gimmizah (G) and Bandara (B), plus one exotic strain of meat-type Ross 308 (R) parents, were used. Combinations of these genotypes were tested on a total of 120 birds from three pure parents. The 180 hatched chicks were divided into three purebreds G×G, B×B, and R×R and three crossbreds R×G, R×B, and G×R and reared for 7 weeks. Body weight and weight gain were recorded for each genetic group. The feed intake and feed conversion ratio were calculated. At the 7th week of age, tissue samples from breast muscle and pituitary gland were collected for IGF gene mRNA expression analysis. The results revealed that the R×R chicks displayed significantly higher final body weight, average daily weight gain, and average daily feed intake when compared to the G×G, B×B, and other crossbred chick lines. While both R×B and G×R crossbred chicks had significantly higher final body weights and average daily weight gains than R×G crossbred chicks and local chicks (G×G and B×B). A better feed conversion ratio was observed in G×R, B×B, R×R and R×B chicks. Crossbred lines (R×B and G×R) had higher dressing percentages than R×G and local breeds. The highest muscular expression of the IGF-II gene was recorded in R×G chicks, while the other crossbred lines, R×B and G×R expressed higher levels of the IGF-II gene than purebred lines. In relation to IGF-I*, R×B chicks had higher relative expression of this gene than other crossbred and purebred lines. When compared to other crossbred lines (R×B and G×R), the expression of IGF-I in brain tissues was significantly higher in the R×G crossbred line. IGF-II and IGF-I* expression levels in brain tissue were higher in the R×G chicks compared to the G×R, G×G, B×B, and R×R chicks. It was concluded that crossing pure Gimmizah or Bandara, as local breeds, with pure Ross 308, as a foreign breed, improved growth traits in the obtained crossbred chicks.

Effect of Cyclooxygenase Inhibition on P-Glycoprotein Expression and Phenytoin Level in Brain Tissue of Pilocarpine Induced Epilepsy in Rats

Effect of Cyclooxygenase Inhibition on P-Glycoprotein Expression and Phenytoin Level in Brain Tissue of Pilocarpine Induced Epilepsy in Rats