Immunocytochemical localization of nitric oxide synthase-containing neurons in the visual cortex of the Mongolian gerbil.

INTRODUCTION: Nitric oxide (NO) is present in various cell types in the central nervous system and plays a crucial role in the control of various cellular functions. The diurnal Mongolian gerbil is a member of the rodent family Muridae that exhibits unique physiological, anatomical, and behavioral differences from the nocturnal rat and mouse, which render it a useful model for studying the visual system. The purpose of this study was to confirm the distribution and morphology of neurons that contain nitric oxide synthase (NOS) and their pattern of co-expressing NOS with neuropeptide Y (NPY), somatostatin (SST), and gamma-aminobutyric acid (GABA) in the visual cortex of Mongolian gerbils. MATERIALS AND METHODS: Mongolian gerbils were used in the study. We confirmed the localization of NOS in the visual cortex of Mongolian gerbils using horseradish peroxidase immunocytochemistry, fluorescent immunocytochemistry, and conventional confocal microscopy. RESULTS: NOS-immunoreactive (IR) neurons were present in all layers of the visual cortex of the Mongolian gerbil, with the exception of layer I, with the highest density observed in layer V (50.00%). The predominant type of NOS-IR neurons was multipolar round/oval cells (60.96%). Two-color immunofluorescence revealed that 100% NOS-IR neurons were co-labeled with NPY and SST and 34.55% were co-labeled with GABA. CONCLUSIONS: Our findings of the laminar distribution and morphological characteristics of NOS-IR neurons, as well as the colocalization patterns of NOS-IR neurons with NPY, SST, and GABA, indicated the presence of species-specific differences, suggesting the functional diversity of NO in the visual cortex. This study provides valuable data on the anatomical organization of NOS-IR neurons and, consequently, a better understanding of the functional aspects of NO and species diversity.

Neuroprotective Effects of Aucubin against Cerebral Ischemia and Ischemia Injury through the Inhibition of the TLR4/NF-κB Inflammatory Signaling Pathway in Gerbils.

Aucubin, an iridoid glycoside, possesses beneficial bioactivities in many diseases, but little is known about its neuroprotective effects and mechanisms in brain ischemia and reperfusion (IR) injury. This study evaluated whether aucubin exhibited neuroprotective effects against IR injury in the hippocampal CA1 region through anti-inflammatory activity in gerbils. Aucubin (10 mg/kg) was administered intraperitoneally once a day for one week prior to IR. Neuroprotective effects of aucubin were assessed by neuronal nuclei (NeuN) immunofluorescence and Floro-Jade C (FJC) histofluorescence. Microgliosis and astrogliosis were evaluated using immunohistochemistry with anti-ionized calcium binding adapter protein 1 (Iba1) and glial fibrillary acidic protein (GFAP). Protein levels of proinflammatory cytokines interleukin1 beta (IL1ß) and tumor necrosis factor alpha (TNFα) were assayed using enzyme-linked immunosorbent assay and Western blot. Changes in toll-like receptor 4 (TLR4)/nuclear factor-κB (NF-κB) signaling pathway were assessed by measuring levels of TLR4, inhibitor of NF-κB alpha (IκBα), and NF-κB p65 using Western blot. Aucubin treatment protected pyramidal neurons from IR injury. IR-induced microgliosis and astrogliosis were suppressed by aucubin treatment. IR-induced increases in IL1ß and TNFα levels were significantly alleviated by the treatment. IR-induced upregulation of TLR4 and downregulation of IκBα were significantly prevented by aucubin treatment, and IR-induced nuclear translocation of NF-κB was reversed by aucubin treatment. Briefly, aucubin exhibited neuroprotective effects against brain IR injury, which might be related to the attenuation of neuroinflammation through inhibiting the TLR-4/NF-κB signaling pathway. These results suggest that aucubin pretreatment may be a potential approach for the protection of brain IR injury.

A New Concept in Antidiabetic Therapeutics: A Concerted Removal of Labile Iron and Intracellular Deposition of Zinc.

BACKGRUOUND: The inflammatory process is known to be an integral part of the pathophysiology of type 2 diabetes mellitus (T2DM). The "labile," redox-active iron, serving as a catalyst in Fenton reaction, producing the deleterious reactive oxygen species, triggering and maintaining inflammation, is hypothesized to play a causative role in this process. Concenter Biopharma continued the development of a new platform of iron chelators (Zygosids), first initiated at the Hebrew University of Jerusalem, Israel (HUJI), acting via the novel mechanism, based on a sequestration of the labile redox-active iron and its substitution by zinc or gallium. The mode of action of Zygosids is based on the higher affinity of the metal-binding moiety of the complex to Fe3+ in comparison to already bound ion, leading to rapid release of the ion of another metal and chelation of Fe3+. Concomitantly, zinc ion, released by the complex, is known for its antidiabetic and anti-inflammatory role. METHODS: The therapeutic effect of zinc-desferrioxamine (Zygosid-50) and gallium-desferrioxamine, was tested on fat sand rat (Psammomys obesus) model of diet-induced T2DM and on Leprdb transgenic diabetic mice. RESULTS: Zygosids demonstrated an ability to noticeably reduce blood glucose and insulin levels and improve the lipid profile. Moreover, an ability to mitigate insulin resistance by >90% was shown on the sand rat model. In addition, a potent anti-inflammatory effect, expressed as a diminishment of the proinflammatory cytokines in tissue levels, was demonstrated. CONCLUSION: Zygosids demonstrated robust therapeutic efficacy in treatment of T2DM. Importantly, no adverse effects were detected, in all the experiments, indicating high safety profile.

Extracts from Dendropanax morbifera leaves ameliorates cerebral ischemia-induced hippocampal damage by reducing oxidative damage in gerbil.

AIM: In this study, we investigated the effects of Dendropanax morbifera extract (DME) on neuroprotection against ischemic damage in gerbils. METHODS: DME (100 or 300 mg/kg) was orally administered to gerbils for three weeks, and 2 h after the last DME treatment, transient forebrain ischemia in the common carotid arteries was induced for 5 min. The forebrain ischemia-related cognitive impairments were assessed by spontaneous motor activity and passive avoidance test one and four days after ischemia, respectively. In addition, surviving and degenerating neurons were morphologically confirmed by neuronal nuclei immunohistochemical staining and Fluoro-Jade C staining, respectively, four days after ischemia. Changes of glial morphology were visualized by immunohistochemical staining for each marker such as glial fibrillary acidic protein and ionized calcium-binding protein. Oxidative stress was determined by measurements of dihydroethidium, O2· (formation of formazan) and malondialdehyde two days after ischemia. In addition, glutathione redox system such as reduced glutathione, oxidized glutathione levels, glutathione peroxidase, and glutathione reductase activities were measured two days after ischemia. RESULTS: Spontaneous motor activity monitoring and passive avoidance tests showed that treatment with 300 mg/kg DME, but not 100 mg/kg, significantly alleviated ischemia-induced memory impairments. In addition, approximately 67 % of mature neurons survived and 29.3 % neurons were degenerated in hippocampal CA1 region four days after ischemia, and ischemia-induced morphological changes in astrocytes and microglia were decreased in the CA1 region after 300 mg/kg DME treatment. Furthermore, treatment with 300 mg/kg DME significantly ameliorated ischemia-induced oxidative stress, such as superoxide formation and lipid peroxidation, two days after ischemia. In addition, ischemia-induced reduction of the glutathione redox system in the hippocampus, assessed two days after the ischemia, was ameliorated by treatment with 300 mg/kg DME. These suggest that DME can potentially reduce ischemia-induced neuronal damage through its antioxidant properties.

Smooth Muscle Actin as a Criterion for Gravisensitivity of Stomach and Jejunum in Laboratory Rodents.

Smooth muscle tissue (SMT) is one of the main structural components of visceral organs, acting as a key factor in the development of adaptive and pathological conditions. Despite the crucial part of SMT in the gastrointestinal tract activity, the mechanisms of its gravisensitivity are still insufficiently studied. The study evaluated the content of smooth muscle actin (α-SMA) in the membranes of the gastric fundus and jejunum in C57BL/6N mice (30-day space flight), in Mongolian gerbils Meriones unguiculatus (12-day orbital flight) and after anti-orthostatic suspension according to E.R. Morey-Holton. A morphometric analysis of α-SMA in the muscularis externa of the stomach and jejunum of mice and Mongolian gerbils from space flight groups revealed a decreased area of the immunopositive regions, a fact indicating a weakening of the SMT functional activity. Gravisensitivity of the contractile structures of the digestive system may be due to changes in the myofilament structural components of the smooth myocytes or myofibroblast actin. A simulated antiorthostatic suspension revealed no significant changes in the content of the α-SMA expression level, a fact supporting an alteration in the functional properties of the muscularis externa of the digestive hollow organs under weightless environment. The data obtained contribute to the novel mechanisms of the SMT contractile apparatus remodeling during orbital flights and can be used to improve preventive measures in space biomedicine.

Expression analysis suggests that DNMT3L is required for oocyte de novo DNA methylation only in Muridae and Cricetidae rodents.

BACKGROUND: During early mammalian development, DNA methylation undergoes two waves of reprogramming, enabling transitions between somatic cells, oocyte and embryo. The first wave of de novo DNA methylation establishment occurs in oocytes. Its molecular mechanisms have been studied in mouse, a classical mammalian model. Current model describes DNA methyltransferase 3A (DNMT3A) and its cofactor DNMT3L as two essential factors for oocyte DNA methylation-the ablation of either leads to nearly complete abrogation of DNA methylation. However, DNMT3L is not expressed in human oocytes, suggesting that the mechanism uncovered in mouse is not universal across mammals. RESULTS: We analysed available RNA-seq data sets from oocytes of multiple mammals, including our novel data sets of several rodent species, and revealed that Dnmt3l is expressed only in the oocytes of mouse, rat and golden hamster, and at a low level in guinea pigs. We identified a specific promoter sequence recognised by an oocyte transcription factor complex associated with strong Dnmt3l activity and demonstrated that it emerged in the rodent clade Eumuroida, comprising the families Muridae (mice, rats, gerbils) and Cricetidae (hamsters). In addition, an evolutionarily novel promoter emerged in the guinea pig, driving weak Dnmt3l expression, likely without functional relevance. Therefore, Dnmt3l is expressed and consequently plays a role in oocyte de novo DNA methylation only in a small number of rodent species, instead of being an essential pan-mammalian factor. In contrast to somatic cells, where catalytically inactive DNMT3B interacts with DNMT3A, forming a heterotetramer, we did not find evidence for the expression of such inactive Dnmt3b isoforms in the oocytes of the tested species. CONCLUSIONS: The analysis of RNA-seq data and genomic sequences revealed that DNMT3L is likely to play a role in oocytes de novo DNA methylation only in mice, rats, gerbils and hamsters. The mechanism governing de novo DNA methylation in the oocytes of most mammalian species, including humans, occurs through a yet unknown mechanism that differs from the current model discovered in mouse.

Tat-CCT2 Protects the Neurons from Ischemic Damage by Reducing Oxidative Stress and Activating Autophagic Removal of Damaged Protein in the Gerbil Hippocampus.

CCT2 is a eukaryotic chaperonin TCP-1 ring complex subunit that mediates protein folding, autophagosome incorporation, and protein aggregation. In this study, we investigated the effects of CCT on oxidative and ischemic damage using in vitro and in vivo experimental models. The Tat-CCT2 fusion protein was efficiently delivered into HT22 cells in a concentration- and time-dependent manner, and the delivered protein was gradually degraded in HT22 cells. Incubation with Tat-CCT2 significantly ameliorated the 200 µM hydrogen peroxide (H2O2)-induced reduction in cell viability in a concentration-dependent manner, and 8 µM Tat-CCT2 treatment significantly alleviated H2O2-induced DNA fragmentation and reactive oxygen species formation in HT22 cells. In gerbils, CCT2 protein was efficiently delivered into pyramidal cells in CA1 region by intraperitoneally injecting 0.5 mg/kg Tat-CCT2, as opposed to control CCT2. In addition, treatment with 0.2 or 0.5 mg/kg Tat-CCT2 mitigated ischemia-induced hyperlocomotive activity 1 d after ischemia and confirmed the neuroprotective effects by NeuN immunohistochemistry in the hippocampal CA1 region 4 d after ischemia. Tat-CCT2 treatment significantly reduced the ischemia-induced activation of astrocytes and microglia in the hippocampal CA1 region 4 d after ischemia. Furthermore, treatment with 0.2 or 0.5 mg/kg Tat-CCT2 facilitated ischemia-induced autophagic activity and ameliorated ischemia-induced autophagic initiation in the hippocampus 1 d after ischemia based on western blotting for LC3B and Beclin-1, respectively. Levels of p62, an autophagic substrate, significantly increased in the hippocampus following treatment with Tat-CCT2. These results suggested that Tat-CCT2 exerts neuroprotective effects against oxidative stress and ischemic damage by promoting the autophagic removal of damaged proteins or organelles.

USP33 promotes nonalcoholic fatty acid disease-associated fibrosis in gerbils via the c-myc signaling.

Nonalcoholic fatty acid disease (NAFLD) is a common complication of obesity associated with liver fibrosis. The underlying molecular mechanisms involved in the progression from normal to fibrosis remain unclear. Liver tissues from the liver fibrosis model identified the USP33 gene as a key gene in NAFLD-associated fibrosis. USP33 knockdown inhibited hepatic stellate cell activation and glycolysis in gerbils with NAFLD-associated fibrosis. Conversely, overexpression of USP33 caused a contrast function on hepatic stellate cell activation and glycolysis activation, which was inhibited by c-Myc inhibitor 10058-F4. The copy number of short-chain fatty acids-producing bacterium Alistipes sp. AL-1, Mucispirillum schaedleri, Helicobacter hepaticus in the feces, and the total bile acid level in serum were higher in gerbils with NAFLD-associated fibrosis. Bile acid promoted USP33 expression and inhibiting its receptor reversed hepatic stellate cell activation in gerbils with NAFLD-associated fibrosis. These results suggest that the expression of USP33, an important deubiquitinating enzyme, is increased in NAFLD fibrosis. These data also point to hepatic stellate cells as a key cell type that may respond to liver fibrosis via USP33-induced cell activation and glycolysis.

Bioaccumulated provitamin A in black soldier fly larvae is bioavailable and capable of improving vitamin A status of gerbils.

The aim was to study whether provitamin A (proVA), which can bioaccumulate in black soldier fly larvae (BSFL), is bioavailable and can restore VA status in mammals. A model for studying the metabolism of this vitamin, the gerbil, was either fed a standard diet (C+ group), a diet without VA (C-), a diet in which VA was provided by ß-carotene (ß-C) from sweet potatoes (SP), or a diet in which VA was provided by ß-C from BSFL that had been fed sweet potatoes (BSFL). The animals were killed at the end of the supplementation period and ß-C, retinol and retinyl esters were measured in plasma and liver. As expected ß-C was not detected in plasma and liver of the C+ and C- groups. ß-C concentrations were lower (p < 0.05) in plasma and liver of the BSFL group as compared to the SP group. Liver retinol and retinyl ester concentrations were lower in the C- group than in all the other groups (p < 0.05). These concentrations were not significantly different in the C+ and SP groups while they were lower in the BSFL group (p < 0.05 for retinyl oleate and retinyl linoleate). In total, the liver stock of retinol equivalent was almost twice lower in the BSFL group than in the SP group. Thus, ß-C present in the BSFL matrix is bioavailable and capable of improving VA status, but this matrix decreases its effectiveness by a factor of around two compared to the sweet potato matrix.

20-Hydroxyecdysone bioavailability and pharmacokinetics in Gerbillus tarabuli, a gerbil model for metabolic syndrome studies.

Phytoecdysteroids are active natural compounds that have demonstrated many beneficial pharmacological effects on mammals, including Humans. 20-Hydroxyecdysone (20E) is the major phytoecdysteroid present in plants, and gerbils are particularly good responders to the addition of 20E to their diet. We have examined the oral bioavailability of 20E in the desert gerbil, Gerbillus tarabuli. 20E (5 and 50 mg.kg-1 body weight) was administered to gerbils by intra-peritoneal injection and oral gavage, respectively. Plasma samples were collected over 8 h and analyzed by HPLC-MS/MS to determine the 20E concentrations. The calculated oral bioavailability of 20E is approx. 12%, with a half-life of 30.6 and 33 min after per os administration or intra-peritoneal injection, respectively. This bioavailabilitty is much higher than that observed in laboratory rodents (ca. 1%). It is proposed that this unexpectedly high oral bioavailability of 20E in gerbils contributes to its high efficacy in this animal.

Genetic Diversity of a Heat Activated Channel-TRPV1 in Two Desert Gerbil Species with Different Heat Sensitivity.

Heat sensation and tolerance are crucial for determining species' survival and distribution range of small mammals. As a member of the transmembrane proteins, transient receptor potential vanniloid 1 (TRPV1) is involved in the sensation and thermoregulation of heat stimuli; however, the associations between animal's heat sensitivity and TRPV1 in wild rodents are less studied. Here, we found that Mongolian gerbils (Meriones unguiculatus), a rodent species living in Mongolia grassland, showed an attenuated sensitivity to heat compared with sympatrically distributed mid-day gerbils (M. meridianus) based on a temperature preference test. To explain this phenotypical difference, we measured the TRPV1 mRNA expression of two gerbil species in the hypothalamus, brown adipose tissue, and liver, and no statistical difference was detected between two species. However, according to the bioinformatics analysis of TRPV1 gene, we identified two single amino acid mutations on two TRPV1 orthologs in these two species. Further Swiss-model analyses of two TRPV1 protein sequences indicated the disparate conformations at amino acid mutation sites. Additionally, we confirmed the haplotype diversity of TRPV1 in both species by expressing TRPV1 genes ectopicly in Escherichia coli system. Taken together, our findings supplemented genetic cues to the association between the discrepancy of heat sensitivity and the functional differentiation of TRPV1 using two wild congener gerbils, promoting the comprehension of the evolutionary mechanisms of the TRPV1 gene for heat sensitivity in small mammals.

Na+/HCO3- Co-transporters Inhibitor S0859 Attenuates Global Cerebral Ischemia-reperfusion Injury of the CA1 Neurons in the Gerbil's Hippocampus.

BACKGROUND: Metabolic acidosis plays a key role in transient global cerebral ischemiareperfusion (I/R) induced delayed neuronal death (DND) of the hippocampal CA1 region of gerbils. Na+ coupled HCO3 - transporters (NBCs) mediated Na+/HCO3- - co-transportation can be activated by the pH gradient of intracellular and extracellular environments induced by acidosis. However, whether NBCs are activated and involved in I/R-induced neuronal injury is unknown. OBJECTIVE: In this work, we studied neuronal apoptosis, astrocyte activation, and hippocampusdependent memory task using a well-established transient global cerebral I/R model of gerbils and investigated whether the specific NBCs inhibitor S0859 could reverse this injury. METHODS: To explore the role of S0859 in I/R-induced DND, we established a transient global cerebral I/R model of Mongolian gerbils and studied neuronal apoptosis by using Nissl stain and TUNEL assay. The excitability and NBCs current were analyzed by whole-cell patch-clamp, while the cognitive function was evaluated by Barnes maze. RESULTS: We found that I/R increased the NBCs current, inhibited the excitability of CA1 neurons, and led to apoptosis in CA1 neurons. Selective NBCs inhibitor S0859 protected CA1 neurons from I/R induced neuronal cell death, astrocyte accumulation, and spatial memory impairment. CONCLUSION: These findings indicate that NBCs mediate transient global cerebral I/R induced DND of CA1 neurons, and NBCs inhibitors could be a promising target to protect neuronal functions after I/R.

Interference of altered plasma trace elements profile with hyperhomocysteinemia and oxidative stress damage to insulin secretion dysfunction in Psammomys obesus: focus on the selenium.

The objective of this study is to investigate the relationship between altered plasma trace elements, particularly selenium (Se), with Hyper-homocysteinemia (HhCys) as a predictive factor of insulin secretion dysfunction. The study is carried out on adult Psammomys obesus, divided in 4 experimental groups: (I) Normoglycemic/Normoinsulinemic; (II) Normoglycemic/Hyperinsulinemic; (III) Hyperglycaemic/Hyperinsulinemic and (IV) Hyperglycaemic/Insulin deficiency with ketoacidosis. The data showed that a drastic depletion of Se plasma levels is positively correlated with HhCys (>15 µmol/L; p < .001), concomitantly with decreased GPx activity, GSH levels, and GSH/GSSG ratio in group IV both in plasma and liver. In contrast, SOD activity is increased (p ≤ .001) in group IV both in plasma and liver. However, plasma Cu and Mn levels increased, while plasma Zn levels decreased in group IV (p < .001). Our study confirms the increase of plasma hCys levels seemed to be a major contributing factor to antioxidant capacities and alters the availability of selenium metabolism by interference with homocysteine synthesis in the insulin secretion deficiency stage.

The Neuroprotective Effects of mGlu1 Receptor Antagonists Are Mediated by an Enhancement of GABAergic Synaptic Transmission via a Presynaptic CB1 Receptor Mechanism.

In this study, we investigated the cross-talk between mGlu1 and CB1 receptors in modulating GABA hippocampal output in whole-cell voltage clamp recordings in rat hippocampal acute slices, in organotypic hippocampal slices exposed to oxygen and glucose deprivation (OGD) and in gerbils subjected to global ischemia. CB1 receptor expression was studied using immunohistochemistry and the CA1 contents of anandamide (AEA) and 2-arachidonoylglycerol (2-AG) were measured by LC-MS/MS. Our results show that mGlu1 receptor antagonists enhance sIPSCs in CA1 pyramidal cells and the basal and ischemic hippocampal release of GABA in vivo in a manner that is mediated by CB1 receptor activation. In hippocampal slices exposed to OGD and in ischemic gerbils, mGlu1 receptor antagonists protected CA1 pyramidal cells against post-ischemic injury and this effect was reduced by CB1 receptor activation. OGD induced a transient increase in the hippocampal content of AEA and this effect is prevented by mGlu1 receptor antagonist. Finally, OGD induced a late disruption of CB1 receptors in the CA1 region and the effect was prevented when CA1 pyramidal cells were protected by mGlu1 antagonists. Altogether, these results suggest a cooperative interaction between mGlu1 receptors and the endocannabinoid system in the mechanisms that lead to post-ischemic neuronal death.

Phosphoglycerate kinase 1 protects against ischemic damage in the gerbil hippocampus.

Phosphoglycerate kinase 1 (PGK1) is a metabolic enzyme that converts 1,3-diphosphoglycerate to 3-phosphoglycerate. In the current study, we synthesized a PEP-1-PGK1 fusion protein that can cross the blood-brain barrier and cell membrane, and the effects of PEP-1-PGK1 against oxidative stress were investigated HT22 cells and ischemic gerbil brain. The PEP-1-PGK1 protein and its control protein (Con-PGK1) were treated and permeability was evaluated HT22 cells. The PEP-1-PGK1 was introduced into HT22 cells depending on its concentration and incubation time and was gradually degraded over 36 h after treatment. PEP-1-PGK1, but not Con-PGK1, significantly ameliorated H2O2-induced cell damage and reactive oxygen species formation in HT22 cells. Additionally, PEP-1-PGK1, but not Con-PGK1, mitigated ischemia-induced hyperlocomotion 1 d after ischemia and 4 d after ischemia of neuronic cell death. PEP-1-PGK1 treatment significantly alleviated the raised lactate and succinate dehydrogenase activities in the early (15 min to 6 h) and late (4 and 7 d) stages of ischemia, respectively. In addition, PEP-1-PGK1 treatment ameliorated the decrease in ATP and pH levels in the late stage (2-7 d) of ischemia. Nuclear factor erythroid-2-related factor 2 (Nrf2) levels accelerated the ischemia-induced increase in the hippocampus 1 d after ischemia after PEP-1-PGK1 treatment. Neuroprotective and ameliorative effects were prominent at a low concentration (0.1 mg/kg), but not at a high concentration (1 mg/kg), of PEP-1-PGK1. Collectively, low concentrations of PEP-1-PGK1 prevented neuronal stress by increasing energy production.

Fermented Mentha arvensis administration provides neuroprotection against transient global cerebral ischemia in gerbils and SH-SY5Y cells via downregulation of the MAPK signaling pathway.

BACKGROUND: Globally, ischemic stroke is a major health threat to humans that causes lifelong disability and death. Mentha arvensis (MA) has been used in traditional medicine to alleviate oxidative stress and inflammation-related disorders. In the present study, the neuroprotective properties of fermented MA (FMA) extract were investigated in the gerbil and SH-SY5Y cells. model of transient global cerebral ischemia. METHODS: Bilateral common carotid artery occlusion-induced transient global cerebral ischemia in gerbil and hydrogen peroxide (H2O2)-mediated neurotoxic effects in human neuroblastoma cells (SH-SY5Y) were investigated. FMA (400 mg/kg) was orally administered for 7 days before induction of ischemic stroke. To evaluate the neuroprotective activity of FMA, we implemented various assays such as cell viability assay (MTT), lactate dehydrogenase (LDH) assay, histopathology, immunohistochemistry (IHC), histofluorescence, and western blot. RESULTS: FMA pretreatment effectively decreased transient ischemia (TI) induced neuronal cell death as well as activation of microglia and astrocytes in the hippocampal region. The protective effects of FMA extract against H2O2-induced cytotoxicity of SH-SY5Y cells were observed by MTT and LDH assay. However, FMA pretreatment significantly increased the expression of the antioxidant marker proteins such as superoxide dismutase-1 (SOD-1) and superoxide dismutase-2 (SOD-2) in the hippocampus and SH-SY5Y cells. Furthermore, the activation of mitogen-activated protein kinase (MAPK) further activated a cascade of outcomes such as neuroinflammation and apoptosis. FMA pretreatment notably decreased TI and H2O2 induced activation of MAPK (c-Jun N-terminal kinase (JNK), extracellular signal-regulated protein kinase (ERK), and p38) proteins in hippocampus and SH-SY5Y cells respectively. Besides, pretreatment with FMA markedly reduced H2O2 mediated Bax/Bcl2 expression in SH-SY5Y cells. CONCLUSION: Thus, these results demonstrated that neuroprotective activities of FMA might contribute to regulating the MAPK signaling pathway.

The neuroprotective effects of phosphoglycerate mutase 5 are mediated by decreasing oxidative stress in HT22 hippocampal cells and gerbil hippocampus.

Phosphoglycerate mutase 5 (PGAM5), a glycolytic enzyme, plays an important role in cell death and regulation of mitochondrial dynamics. In this study, we investigated the effects of PGAM5 on oxidative stress in HT22 hippocampal cells and ischemic damage in the gerbil hippocampus to elucidate the role of PGAM5 in oxidative and ischemic stress. Constructs were designed with a PEP-1 expression vector to facilitate the intracellular delivery of PGAM5 proteins. We observed time- and concentration-dependent increases in the intracellular delivery of the PEP-1-PGAM5 protein, but not its control protein (PGAM5), in HT22 cells, and morphologically demonstrated the localization of the transduced protein, which was stably expressed in the cytoplasm after 12 h of PEP-1-PGAM5 treatment. PEP-1-PGAM5 treatment significantly ameliorated cell death, reactive oxygen species formation, DNA fragmentation, and the reduction of cell proliferation induced by H2O2 treatment in HT22 cells. In addition, PEP-1-PGAM5 was effectively delivered to the gerbil hippocampus 8 h after treatment, and ischemia-induced hyperlocomotion and neuronal death in the hippocampal CA1 region were significantly alleviated 1 and 4 days after ischemia, respectively. Ischemia-induced microglial activation was also mitigated by treatment with 1.0 mg/kg PEP-1-PGAM5. At 3 h after ischemia, PEP-1-PGAM5 treatment significantly ameliorated the increase in lipid peroxidation, as assessed by malondialdehyde and hydroperoxide levels, and decreased glutathione levels (increases in glutathione disulfide, the oxidized form of glutathione) in the hippocampus. Two days after ischemia, treatment with PEP-1-PGAM5 significantly alleviated the ischemia-induced reduction in glutathione peroxidase activity and further increased superoxide dismutase activity in the hippocampus. The neuroprotective effects of PEP-1-PGAM5 are partially mediated by a reduction in oxidative stress, such as the formation of reactive oxygen species, and increases in the activity of antioxidants such as glutathione peroxidase and superoxide dismutase.

Relationship between Neuronal Damage/Death and Astrogliosis in the Cerebral Motor Cortex of Gerbil Models of Mild and Severe Ischemia and Reperfusion Injury.

Neuronal loss (death) occurs selectively in vulnerable brain regions after ischemic insults. Astrogliosis is accompanied by neuronal death. It can change the molecular expression and morphology of astrocytes following ischemic insults. However, little is known about cerebral ischemia and reperfusion injury that can variously lead to damage of astrocytes according to the degree of ischemic injury, which is related to neuronal damage/death. Thus, the purpose of this study was to examine the relationship between damage to cortical neurons and astrocytes using gerbil models of mild and severe transient forebrain ischemia induced by blocking the blood supply to the forebrain for five or 15 min. Significant ischemia tFI-induced neuronal death occurred in the deep layers (layers V and VI) of the motor cortex: neuronal death occurred earlier and more severely in gerbils with severe ischemia than in gerbils with mild ischemia. Distinct astrogliosis was detected in layers V and VI. It gradually increased with time after both ischemiae. The astrogliosis was significantly higher in severe ischemia than in mild ischemia. The ischemia-induced increase of glial fibrillary acidic protein (GFAP; a maker of astrocyte) expression in severe ischemia was significantly higher than that in mild ischemia. However, GFAP-immunoreactive astrocytes were apparently damaged two days after both ischemiae. At five days after ischemiae, astrocyte endfeet around capillary endothelial cells were severely ruptured. They were more severely ruptured by severe ischemia than by mild ischemia. However, the number of astrocytes stained with S100 was significantly higher in severe ischemia than in mild ischemia. These results indicate that the degree of astrogliosis, including the disruption (loss) of astrocyte endfeet following ischemia and reperfusion in the forebrain, might depend on the severity of ischemia and that the degree of ischemia-induced neuronal damage may be associated with the degree of astrogliosis.

The complex role of telocytes in female prostate tumorigenesis in a rodent model.

The prostate is not an organ exclusive to the male. It is also found in females of several species, including humans, in which part of the Skene gland is homologous to the male prostate. Evidence is accumulating that changes in the stroma are central to tumorigenesis. Equally, telocytes, a recently discovered type of interstitial cell, are essential for the maintenance of stromal organization. However, it is still uncertain whether there are telocytes in the female prostate and if they play a role in tumorigenesis. The present study used ultrastructural and immunofluorescence techniques to investigate the presence of telocytes in the prostate of Mongolian gerbil females, a rodent model that often has a functional prostate in females, as well as to assess the impact of a combination of N-ethyl-N-nitrosourea, testosterone, and estradiol on telocytes. The results point to the presence of telocytes in the female prostate in the perialveolar and interalveolar regions, and reveal that these cells are absent in regions of benign and premalignant lesions in the gland, in which the perialveolar smooth muscle is altered. Additionally, telocytes are also closely associated with infiltrated immune cells in the stroma. Our data suggest that telocytes are important for both the maintenance of smooth muscle and prostatic epithelium integrity, which indicates a protective role against the advancement of tumorigenesis. But telocytes are also associated with immune cells and a proinflammatory/proangiogenic role for these cells cannot be ruled out, implying that telocytes have a complex role in prostatic tumorigenesis in females.

Astaxanthin Confers a Significant Attenuation of Hippocampal Neuronal Loss Induced by Severe Ischemia-Reperfusion Injury in Gerbils by Reducing Oxidative Stress.

Astaxanthin is a powerful biological antioxidant and is naturally generated in a great variety of living organisms. Some studies have demonstrated the neuroprotective effects of ATX against ischemic brain injury in experimental animals. However, it is still unknown whether astaxanthin displays neuroprotective effects against severe ischemic brain injury induced by longer (severe) transient ischemia in the forebrain. The purpose of this study was to evaluate the neuroprotective effects of astaxanthin and its antioxidant activity in the hippocampus of gerbils subjected to 15-min transient forebrain ischemia, which led to the massive loss (death) of pyramidal cells located in hippocampal cornu Ammonis 1-3 (CA1-3) subfields. Astaxanthin (100 mg/kg) was administered once daily for three days before the induction of transient ischemia. Treatment with astaxanthin significantly attenuated the ischemia-induced loss of pyramidal cells in CA1-3. In addition, treatment with astaxanthin significantly reduced ischemia-induced oxidative DNA damage and lipid peroxidation in CA1-3 pyramidal cells. Moreover, the expression of the antioxidant enzymes superoxide dismutase (SOD1 and SOD2) in CA1-3 pyramidal cells were gradually and significantly reduced after ischemia. However, in astaxanthin-treated gerbils, the expression of SOD1 and SOD2 was significantly high compared to in-vehicle-treated gerbils before and after ischemia induction. Collectively, these findings indicate that pretreatment with astaxanthin could attenuate severe ischemic brain injury induced by 15-min transient forebrain ischemia, which may be closely associated with the decrease in oxidative stress due to astaxanthin pretreatment.