α-Linolenic Acid Induces Microglial Activation and Extracellular Tau Internalization.

Neuroinflammation is the brain condition that occurs due to the hyper-activation of brain's immune cells and microglia, over the stimulation of extracellular aggregated proteins such as amyloid plaques and by extracellular Tau as well. The phenotypic changes of microglia from inflammatory to anti-inflammatory can be triggered by many factors, which also includes dietary fatty acids. The classes of omega-3 fatty acids are the majorly responsible in maintaining the anti-inflammatory phenotype of microglia. The enhanced phagocytic ability of microglia might induce the clearance of extracellular aggregated proteins, such as amyloid beta and Tau. In this study, we emphasized on the effect of α-linolenic acid (ALA) on the activation of microglia and internalization of the extracellular Tau seed in microglia.

Dietary wheat gluten induces astro- and microgliosis in the hypothalamus of male mice.

Gluten, which is found in cereals such as wheat, rye and barley, makes up a major dietary component in most western nations, and has been shown to promote body mass gain and peripheral inflammation in mice. In the current study, we investigated the impact of gluten on central inflammation that is typically associated with diet-induced obesity. While we found no effect of gluten when added to a low-fat diet (LFD), male mice fed high fat diet (HFD) enriched with gluten increased body mass and adiposity compared with mice fed HFD without gluten. We furthermore found that gluten, when added to the LFD, increases circulating C-reactive protein levels. Gluten regardless of whether it was added to LFD or HFD led to a profound increase in the number of microglia and astrocytes in the arcuate nucleus of the hypothalamus, as detected by immunohistochemistry for ionised calcium binding adaptor molecule 1 (Iba-1) and glial fibrillary acidic protein (GFAP), respectively. In mice fed LFD, gluten mimicked the immunogenic effects of HFD exposure and when added to HFD led to a further increase in the number of immunoreactive cells. Taken together, our results confirm a moderate obesogenic effect of gluten when fed to mice exposed to HFD and for the first-time report gluten-induced astro- and microgliosis suggesting the development of hypothalamic injury in rodents.

The neuroprotective effect of ginsenoside Rb1 on the cerebral cortex changes induced by aluminium chloride in a mouse model of Alzheimer's disease: A histological, immunohistochemical, and biochemical study.

Alzheimer's disease (AD) is one of the most common types of dementia among neurodegenerative disorders characterized by attention deficits and memory loss. Panax ginseng is a traditional Chinese herbal remedy that has been employed for millennia to manage dementia linked with aging and memory impairment. Ginsenoside Rb1 is one of Panax ginseng's most abundant components. The present work evaluated the neuroprotective effects of ginsenoside Rb1 on the cerebral cortex of AlCl3-induced AD in adult male albino mice. Forty male mice were alienated arbitrarily into; control group, ginsenoside Rb1 group (70 mg/kg/day), AlCl3 group (50 mg/kg/day), and ginsenoside Rb1-AlCl3 group that received ginsenoside Rb1 one hour before AlCl3. Oxidative stress parameters, Amyloid ß (Aß) and phosphorylated tau protein, and acetylcholine esterase (AChE) activity were measured. Cerebral cortex sections were evaluated histologically by light microscopic examination and immunohistochemistry. AlCl3-induced memory impairment, Aß and phosphorylated tau protein accumulation, and AChE elevation. Moreover, histopathological alterations in the cerebral cortex were reported in the form of irregular shrunken neurons and the surrounding neuropil showed vacuolation. Some neurons appeared with darkly stained nuclei, others had faintly stained ones. The synaptophysin expression was significantly decreased, while the expression of cleaved caspase-3, glial fibrillary acidic protein (GFAP), and ionized calcium-binding adaptor molecule 1 (Iba-1) were significantly elevated. It's interesting to note that these changes were attenuated in mice pretreated with ginsenoside Rb1. Collected data indicated that ginsenoside Rb1 showed a potential neuroprotective effect against cerebral cortex changes caused by AlCl3 via suppression of Amyloid ß and phosphorylated tau protein formation, oxidative stress correction, anti-apoptotic effect, and by minimizing gliosis.

rTg-D: A novel transgenic rat model of cerebral amyloid angiopathy Type-2.

Background: Cerebral amyloid angiopathy (CAA) is common disorder of the elderly, a prominent comorbidity of Alzheimer's disease, and causes vascular cognitive impairment and dementia. Previously, we generated a transgenic rat model of capillary CAA type-1 that develops many pathological features of human disease. However, a complementary rat model of larger vessel CAA type-2 disease has been lacking. Methods: A novel transgenic rat model (rTg-D) was generated that produces human familial CAA Dutch E22Q mutant amyloid ß-protein (Aß) in brain and develops larger vessel CAA type-2. Quantitative biochemical and pathological analyses were performed to characterize the progression of CAA and associated pathologies in aging rTg-D rats. Results: rTg-D rats begin to accumulate Aß in brain and develop varying levels of larger vessel CAA type-2, in the absence of capillary CAA type-1, starting around 18 months of age. Larger vessel CAA was mainly composed of the Aß40 peptide and most prominent in surface leptomeningeal/pial vessels and arterioles of the cortex and thalamus. Cerebral microbleeds and small vessel occlusions were present mostly in the thalamic region of affected rTg-D rats. In contrast to capillary CAA type-1 the amyloid deposited within the walls of larger vessels of rTg-D rats did not promote perivascular astrocyte and microglial responses or accumulate the Aß chaperone apolipoprotein E. Conclusion: Although variable in severity, the rTg-D rats specifically develop larger vessel CAA type-2 that reflects many of the pathological features of human disease and provide a new model to investigate the pathogenesis of this condition.

Acupuncture points injection mitigates chronic pain through transient receptor potential V1 in mice.

Objectives: Tissue injury in peripheral sites can result in long-term potentiation in nociceptive neurons and surrounding glial cells, potentially resulting in the development of chronic inflammatory pain (CIP). Acupoint injection (AI) is similar to Western phototherapy, which injects solutions at specific sites to mitigate chronic pain. AI has shown greater benefits compared with acupuncture. In this study, we examined the therapeutic effect and explored the underlying mechanisms of AI in mice CIP model. Materials and Methods: We injected thrice complete Freund's adjuvant (CFA) into the mouse's hind paw to induce CIP. Results: We found that, after two weeks, CFA injection significantly induced mechanical and thermal hyperalgesia which were attenuated by AI treatment. Transient receptor potential V1 (TRPV1) channels and associated molecules were all increased in CIP in mice dorsal root ganglion (DRG), spinal cord (SC), thalamus, and somatosensory cortex (SSC). The aforementioned molecules were mitigated in AI and Trpv1 knockout mice. Furthermore, Iba1-positive cells (microglial marker) were also potentiated and shared a similar tendency with TRPV1. Conclusion: These findings suggest that AI can alleviate chronic pain by reducing TRPV1 overexpression in both neuronal and microglial cells. Our results suggest new potential therapeutic targets for AI in chronic pain.

Effects of modified Zhujing pill on retinal autophagy in mice with form deprivation myopia / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To investigate the effect of modified Zhujing pill on retinal autophagy in mice with form deprivation myopia.METHODS: Thirty C57BL/6 mice were randomly divided into a negative control group, a myopia model group and a traditional Chinese medicine intervention group, with 10 mice in each group. Except for the negative control group, all mice in the myopia model group and the traditional Chinese medicine intervention group used translucent EP tubes to cover their right eyes to make a form deprivation myopia(FDM)model; The traditional Chinese medicine intervention group gavage Zhujing pill modified suspension 0.546g/(kg·d)(0.15mL/d), the negative control group and the myopia model group were given an equal amount of normal saline(0.15mL/d)for 4wk. At the beginning and the end of the experiment respectively, the right eye diopter of the mouse was measured with a strip retinoscope, measurement of the axial length of the right eye of mouse by A-ultrasound. At the end of the experiment, the right eyes of all mice were taken for detection, and immunofluorescence method was used to locate and detect the activity and migration of the retinal microglia marker(Iba1); Transmission electron microscope observation of autophagosome formation in retinal pigment epithelial cells; Western Blot, real-time fluorescent quantitative PCR(q-PCR)to detect the autophagy marker LC3Ⅱ and p62 protein quantitative and gene expression in retinal tissues.RESULTS: At the end of the experiment, the refractive power of the right eyes of mice showed that the myopia model group and the traditional Chinese medicine intervention group formed relative myopia, the myopia model group and the traditional Chinese medicine intervention group were significantly lower than those of the negative control group(all P<0.01). At the end of the experiment, the axial length of the myopia model group and the Chinese medicine intervention group were significantly increased compared with the negative control group(P<0.01). Immunofluorescence method for locating and detecting Iba1 showed that the average optical density of Iba1 in the retina of the myopia model group increased the most obviously, followed by the increase in the negative control group, and the decrease in the traditional Chinese medicine intervention group. Compared with the negative control group, the myopia model group increased significantly(P<0.05), and the traditional Chinese medicine intervention group was significantly lower than the myopia model group(P<0.05). It was found that Iba1 migrated to the ganglion cell layer in the myopia model group and the traditional Chinese medicine intervention group. Transmission electron microscopy showed that autophagosomes were observed in the retinal pigment epithelial cells of the myopia model group and the Chinese medicine intervention group. The results of Western Blot and q-PCR showed that the expression of LC3Ⅱ and p62 increased most obviously in the traditional Chinese medicine intervention group, followed by the myopia model group, and the negative control group was the lowest.CONCLUSION: The results of the study show that modified Zhujing pill may enhance retinal autophagy in mice with FDM by inhibiting the activation of microglia.

Serum Levels of the Biomarkers Associated with Astrocytosis, Neurodegeneration, and Demyelination: Neurological Benefits of Citicoline Treatment of Patients with Ischemic Stroke and Atrial Fibrillation.

Ischemic stroke is a main complication of atrial fibrillation (cardiac arrhythmia). The aim of our study was to estimate the effects of citicoline (CDP-choline) therapy on the levels of circulating neurospecific protein markers in serum of the patients with ischemic stroke and atrial fibrillation. Fiftyfour patients (mean age 76 years) treated with citicoline in a dose of 2.0 g daily intravenously for 12 to 14 days in addition to basic treatment formed the examined group. Thirty-two patients (mean age 68.5 years) obtained only standard therapy and formed the control group. Serum levels of neuronal and glial protein markers, including glial fibrillary acidic protein (GFAP), a neurofilament light subunit (NF-L), myelin basic protein (MBP), and ionized calcium-binding adaptor molecule 1 (Iba1), were measured in patients of both groups before and after treatment; an immunoblotting technique followed by densitometry analysis were used. Supplementary citicoline treatment provided significant reductions of the levels of GFAP (33%, P = 0.034), NF-L (27%, P = 0.019), and MBP (32%, P = 0.018), as compared to the initial values, while there were no marked changes in the studied parameters in the control group. The results obtained allow us to hypothesize that therapeutic benefit of citicoline in patients with ischemic stroke and atrial fibrillation can be mediated through increasing neuronal viability, protecting against axonal injury, decreasing the level of reactive astrogliosis, preventing deficiencies in the blood-brain integrity, and reducing the intensity of demyelination. However, citicoline administration exerted no effect on the blood content of microglial marker Iba-1, thus possibly preserving an important functional significance of microglia, which is needed to resolve local inflammation and clear cellular debris, and also provide protective factors to reduce cell injury in the ischemic brain. The obtained results indicate that serum levels of neurospecific biomarkers are significant and clinically relevant indices of the efficiency of treatment of the above-mentioned pathologies and can be used for further investigations of the stroke pathophysiology and molecular mechanisms of nootropic-mediated neuroprotection.

Gisenoside Rg1 attenuates cadmium-induced neurotoxicity in vitro and in vivo by attenuating oxidative stress and inflammation.

OBJECTIVE: Gisenoside Rg1 is a potent neuroprotectant in ginseng. The aim of this study was to investigate the elimination effect of Rg1 on cadmium (Cd)-induced neurotoxicity. MATERIALS AND METHODS: A cumulative Cd exposure mouse model was established. Also, the toxicity of Cd and the protective effect of Rg1 were examined in vitro using cultured neurons and microglia. RESULTS: We found that Cd-intoxicated mice exhibited significant injury in the liver, kidney, small intestine, and testis, along with cognitive impairment. Antioxidant enzymes such as SOD, GSH-Px and CAT were reduced in the blood and brain, and correspondingly, the lipid peroxidation product MDA was elevated. In the brain, astrocytes and microglia were activated, characterized by an increase in inflammatory factors such as TNF-α, IL-1ß and IL-6, as well as their protein markers GFAP and IBA1. However, Rg1 eliminated Cd-induced toxicity and restored oxidative stress and inflammatory responses, correspondingly restoring the behavioral performance of the animals. Meanwhile, the BDNF-TrkB/Akt and Notch/HES-1 signaling axes were involved in the Rg1-mediated elimination of Cd-induced toxicity. CONCLUSION: Rg1 is a promising agent for the elimination of Cd-induced toxicity.

(-)-Syringaresinol suppressed LPS-induced microglia activation via downregulation of NF-κB p65 signaling and interaction with ERß.

Albiziae Cortex (AC) is a well-known traditional Chinese medicine with sedative-hypnotic effects and neuroprotective ability. However, the bioactive components of AC responsible for the neuro-protective actitivity remain unknown. Here, we investigated the anti-neuroinflammatory effects of (-)-syringaresinol (SYR) extracted from AC in microglia cells and wild-type mice. As a result, (-)-SYR significantly reduced lipopolysaccharide (LPS)-induced production of interleukin - 6 (IL-6), tumor necrosis factor α (TNF-α), interleukin -1 beta (IL-1ß), cycloxygenase-2 (COX-2), and nitric oxide (NO) in BV2 microglia cells. (-)-SYR also significantly reduced M1 marker CD40 expression and increased M2 marker CD206 expression. Moreover, we found that (-)-SYR inhibited LPS-induced NF-κB activation by suppressing the translocation of NF-κB p65 into the nucleus in a concentration-dependent manner. Meanwhile, estrogen receptor ß (ERß) was found to be implied in the anti-inflammatory activity of (-)-SYR in BV2 microglia. In vivo experiments revealed that administration of (-)-SYR in mice significantly reduced microglia/astrocytes activation and mRNA levels of proinflammatory mediators. Taken together, our data indicated that (-)-SYR exerted the anti-neuroinflammatory effects by inhibiting NF-κB activation and modulation of microglia polarization, and via interaction with ERß. The anti-neuroinflammatory activity of (-)-SYR may provide a new therapeutic avenue for the treatment of brain diseases associated with inflammation.

Regional microglial populations in central autonomic brain regions in SUDEP.

OBJECTIVE: Sudden unexpected death in epilepsy (SUDEP) may arise as a result of autonomic dysfunction during a seizure. The central autonomic networks (CANs) modulate brainstem cardiorespiratory regulation. Recent magnetic resonance imaging (MRI) studies in SUDEP have shown cortical and subcortical volume changes and altered connectivity between CAN regions, but the pathological correlate is unknown. Because neuroinflammation is both a cause and a consequence of seizures and may relate to regional brain pathology, our aim was to evaluate microglial populations in CANs in SUDEP. METHODS: In 55 postmortem cases, including SUDEP, epilepsy controls without SUDEP and nonepilepsy controls, we quantified Iba1-expressing microglia in 14 cortical and thalamic areas that included known CAN regions. RESULTS: Mean Iba1 labeling across all brain regions was significantly higher in SUDEP cases compared to epilepsy and nonepilepsy controls. There was significant regional variation in Iba1 labeling in SUDEP cases only, with highest labeling in the medial thalamus. Significantly higher labeling in SUDEP cases than epilepsy and nonepilepsy controls was consistently noted in the superior temporal gyrus. In cases with documented seizures up to 10 days prior to death, significantly higher mean Iba1 labeling was observed in SUDEP compared to epilepsy controls. SIGNIFICANCE: Our findings support microglial activation in SUDEP, including cortical and subcortical regions with known autonomic functions such as the thalamus and superior temporal gyrus. This may be relevant to cellular pathomechanisms underlying cardioregulatory failure during a seizure.

[Effect of Xiaoyao San on OVX combined with CUS anxiety and depression model rats based on hippocampal microglia M1 polarization].

To investigate the anti-anxiety and anti-depression effect and mechanism of Xiaoyao San on rats with ovariectomy(OVX) combined with chronic unpredictable stress(CUS) model. The model of perimenopausal depression was established by OVX and CUS; the level of anxiety and depression was evaluated by open field test; the levels of interleukin-1ß(IL-1ß) and interleukin-6(IL-6) mRNA in rat hippocampus were detected by Real-time qPCR; double staining immunofluorescence was used to detect the expression of ionized calcium binding adaptor molecule-1(Iba-1) and inducible nitric oxide synthase(iNOS) in microglia of rat dentate gyrus(DG); Western blot was used to detect the protein expression of Iba-1 and iNOS of microglia in DG region of rat hippocampus. The results showed that in the model group, the number of horizontal movement, the number of vertical movement and central residence time were significantly reduced, and the grooming time was significantly prolonged(P<0.05 or P<0.01); the levels of IL-1ß and IL-6 in hippocampus increased significantly(P<0.05); the number of positive cells with co-expression of Iba-1/iNOS of microglia cells in DG region of hippocampus increased; the expression levels of Iba-1 and iNOS protein in hippocampus were significantly increased(P<0.01), suggesting that microglia in DG region of hippocampus was activated and polarized toward M1 type in rats with stress. The high dose group of Xiaoyao San significantly increased the number of horizontal movement, vertical movement and central residence time of model rats(P<0.05 or P<0.01), and significantly down-regulated the levels of inflammatory factors IL-1ß and IL-6(P<0.05). Meanwhile, it reversed the activation and quantity change of microglia in hippocampus. Although the Xiaoyao San low dose group had no significant effect on the behavioral indicators in the open field test and the levels of IL-1ß and IL-6, they all showed a trend of improvement. Low dose Xiaoyao San significantly decreased iNOS protein level(P<0.05), and high dose Xiaoyao San significantly down-regulated the protein expression of Iba-1 and iNOS in hippocampus microglia(P<0.05 or P<0.01). In conclusion, Xiaoyao San can improve anxiety and depression-like behavior in OVX combined with CUS model rats, and its mechanism is related to its anti-inflammatory effect by inhibiting M1 polarization of hippocampal microglia.

The effects of ozone exposure and sedentary lifestyle on neuronal microglia and mitochondrial bioenergetics of female Long-Evans rats.

Ozone (O3) is a widespread air pollutant that produces cardiovascular and pulmonary dysfunction possibly mediated by activation of central stress centers. Epidemiological data suggest that sedentary lifestyles may exacerbate responses to air pollutants such as O3. We sought to assess neurological changes in response to O3 exposure and an active lifestyle. We developed an animal model in which female Long-Evans rats were either sedentary or active with continuous access to running wheels starting at postnatal day (PND) 22 until the age of PND 100 and then exposed to O3 (0, 0.25, 0.5 or 1.0 ppm) 5 h/day for two consecutive days. We found significantly more reactive microglia within the hippocampus (HIP) in animals exposed to O3 in both sedentary and active rats. No changes were detected in astrocytic coverage. We next analyzed mitochondrial bioenergetic parameters (complex I, complex II and complex IV). Complex I activity was significantly affected by exercise in hypothalamus (HYP). Complex II activity was significantly affected by both exercise and O3 exposure in the HIP. Concomitant with the changes in enzymatic activity, there were also effects on expression of genes related to mitochondrial bioenergetics and antioxidant production. These results demonstrate that O3 induces microglia reactivity within stress centers of the brain and that mitochondrial bioenergetics are altered. Some of these effects may be augmented by exercise, suggesting a role for lifestyle in O3 effects on brain mitochondrial bioenergetics parameters in agreement with our previous reports on other endpoints.

Estradiol Increases Microglial Response to Lipopolysaccharide in the Ventromedial Hypothalamus during the Peripubertal Sensitive Period in Female Mice.

Sensitive periods are times of development during which the effects of experience are unusually strong and long lasting. The peripubertal period has emerged as one such sensitive period, and a single administration of lipopolysaccharide (LPS) during this time reduces hormone-induced sexual behavior in adult female mice. During periods of high synaptic turnover, maturation, and elimination, as occurs during this sensitive period, microglia are particularly active. Estradiol also regulates microglial numbers, morphology, and activation. In addition, a good deal of evidence suggests that estradiol may confer this vulnerability to the effects of a stressor during the peripubertal period. Therefore, we investigated the effects of estradiol on microglial morphology, cytokine levels, and the sickness response to LPS. Estradiol levels were manipulated by implanting an estradiol-filled SILASTIC capsule (or oil-filled control) in ovariectomized mice or by administering the aromatase inhibitor, formestane (or oil control), to ovary-intact mice. We found that (1) estradiol elevates basal microglial Iba1 immunoreactivity in the ventromedial nucleus of the hypothalamus (VMH), (2) LPS induces higher levels of proinflammatory cytokines in the presence of estradiol, and (3) LPS causes hypothermia in the presence of estradiol. Taken together, these data suggest that estradiol enhances the effect of LPS during the pubertal sensitive period.

Neuroprotective and Anti-Inflammatory Effects of a Hydrophilic Saffron Extract in a Model of Glaucoma.

Glaucoma is a neurodegenerative disease characterized by the loss of retinal ganglion cells (RGCs). An increase in the intraocular pressure is the principal risk factor for such loss, but controlling this pressure does not always prevent glaucomatous damage. Activation of immune cells resident in the retina (microglia) may contribute to RGC death. Thus, a substance with anti-inflammatory activity may protect against RGC degeneration. This study investigated the neuroprotective and anti-inflammatory effects of a hydrophilic saffron extract standardized to 3% crocin content in a mouse model of unilateral, laser-induced ocular hypertension (OHT). Treatment with saffron extract decreased microglion numbers and morphological signs of their activation, including soma size and process retraction, both in OHT and in contralateral eyes. Saffron extract treatment also partially reversed OHT-induced down-regulation of P2RY12. In addition, the extract prevented retinal ganglion cell death in OHT eyes. Oral administration of saffron extract was able to decrease the neuroinflammation associated with increased intraocular pressure, preventing retinal ganglion cell death. Our findings indicate that saffron extract may exert a protective effect in glaucomatous pathology.

Sequential alteration of microglia and astrocytes in the rat thalamus following spinal nerve ligation.

BACKGROUND: Spinal reactive astrocytes and microglia are known to participate to the initiation and maintenance of neuropathic pain. However, whether reactive astrocytes and microglia in thalamic nuclei that process sensory-discriminative aspects of pain play a role in pain behavior remains poorly investigated. Therefore, the present study evaluated whether the presence of reactive glia (hypertrophy, increased number and upregulation of glial markers) in the ventral posterolateral thalamic nucleus (VPL) correlates with pain symptoms, 14 and 28 days after unilateral L5/L6 spinal nerve ligation (SNL) in rats. METHODS: Mechanical allodynia and hyperalgesia (von Frey filament stimulation) as well as ambulatory pain (dynamic weight bearing apparatus) were assessed. Levels of nine glial transcripts were determined by quantitative real-time PCR on laser microdissected thalamic nuclei, and levels of proteins were assessed by Western blot. We also studied by immunohistofluorescence the expression of glial markers that label processes (GFAP for astrocytes and iba-1 for microglia) and cell body (S100ß for astrocytes and iba-1 for microglia) and quantified the immunostained surface and the number of astrocytes and microglia (conventional counts and optical dissector method of stereological counting). RESULTS: Differential, time-dependent responses were observed concerning microglia and astrocytes. Specifically, at day 14, iba-1 immunostained area and number of iba-1 immunopositive cells were decreased in the VPL of SNL as compared to naïve rats. By contrast, at day 28, GFAP-immunostained area was increased in the VPL of SNL as compared to naïve rats while number of GFAP/S100ß immunopositive cells remained unchanged. Using quantitative real-time PCR of laser microdissected VPL, we found a sequential increase in mRNA expression of cathepsin S (day 14), fractalkine (day 28), and fractalkine receptor (day 14), three well-known markers of microglial reactivity. Using Western blot, we confirmed an increase in protein expression of fractalkine receptor at day 14. CONCLUSIONS: Our results demonstrate a sequential alteration of microglia and astrocytes in the thalamus of animals with lesioned peripheral nerves. Furthermore, our data report unprecedented concomitant molecular signs of microglial activation and morphological signs of microglial decline in the thalamus of these animals.

Protective effects of Alpinae Oxyphyllae Fructus extracts on lipopolysaccharide-induced animal model of Alzheimer's disease.

ETHNOPHARMACOLOGICAL RELEVANCE: Alpinae Oxyphyllae Fructus (AOF) with warming and tonifying the kidney and spleen, anti-salivation, anti-polyuria and anti-diarrhea functions is the dried ripe fruits of Alpinia oxyphylla Miq. (Zingiberaceae). As a traditional Chinese medicine, its application history is very long. AIMS OF THE STUDY: The purpose of our study is to investigate the effects of different solvent extracts from AOF on lipopolysaccharide (LPS)-induced animal model of Alzheimer's disease (AD) to elucidate the traditional medical theories with modern pharmacological methods and provide a reference for further clarifying its active components and mechanisms. MATERIALS AND METHODS: The method of stepwise screening was adopted in this paper. The animals were divided into 9 groups, including control (CT) group, model (MD) group, donepezil (DPZ) group, total extract (TT) group, petroleum ether extract (PE) group, chloroform extract (CF) group, ethyl acetate extract (EA) group, n-butanol extract (NB) group and water extract (WT) group. The anti-amnesic effects of different solvent extracts from AOF were measured in LPS-induced memory deficits mice by Y maze test and Morris water maze (MWM) test. Hematoxylin eosin (HE) staining was applied to observe pathological changes in hippocampus and cerebral cortex tissue of different groups. Biochemical indicators including ionized calcium-binding adaptor molecule 1 (IBA-1), interleukin beta 1 (IL-1ß), Aß1-42 and hyperphosphorylated tau proteins (p-tau) in hippocampus and cortex after treatment with LPS were measured according to the manufacturer's instructions of ELISA kits. HPLC was used to evaluate the major components of different extracts. RESULTS: It was found that successive intragastric administration of AOF (360 mg/kg) extracts for 14 days showed different degrees of improvement on LPS-induced AD model as measured by Y-maze test, Morris water maze test, and Histopathological examination. Moreover, the results of ELISA suggested petroleum ether (PE) extracts were worth recommending for inhibiting the high level of IBA-1, IL-1ß, Aß1-42 and p-tau in hippocampus and cortex after treatment with LPS. CONCLUSIONS: The present study demonstrated for the first time that AOF attenuated LPS-induced learning and memory impairment, which may be associated with its inhibitory effect on neuroinflammation, amyloids-ß (Aß) deposition and p-tau. This research provided a theoretical basis for elucidating the traditional theory of AOF, and was also the stepping stone to the next step.

The yin/yang of inflammatory status: Blood-brain barrier regulation during sleep.

Sleep loss induces a low-grade inflammatory status characterized by a subtle but sustained increase of pro-inflammatory mediators, which are key regulators of blood-brain barrier function. To investigate the influence of inflammatory status on blood-brain barrier dysfunction induced by sleep restriction we performed an experiment using two strains of mice with different immunological backgrounds, C57BL/6 mice that have a predominant pro-inflammatory response and BALB/c mice that have a predominant anti-inflammatory response. Mice were sleep-restricted during 10 days using the flowerpot technique during 20 h per day with 4 h of daily sleep opportunity. The systemic inflammatory status, blood-brain barrier permeability, and the hippocampal expression of neuroinflammatory markers were characterized at the 10th day. Serum levels of TNF and IFN-γ increased in sleep-restricted C57BL/6 but not in BALB/c mice; no changes in other cytokines were found. Sleep restriction increased blood-brain barrier permeability in C57BL/6 strain but not in BALB/c. The hippocampus of sleep-restricted C57BL/6 mice exhibited an increase in the expression of the neuroinflammatory markers Iba-1, A2A adenosine receptor, and MMP-9; meanwhile in sleep-restricted BALB/c mice the expression of this markers was lesser than the control group. These data suggest that cytokines may be playing a key role in modulating blood-brain barrier function during sleep restriction, and probably the effects are related to Iba-1, MMP-9 and A2A adenosine receptor overexpression.

Astrocyte IKKß/NF-κB signaling is required for diet-induced obesity and hypothalamic inflammation.

OBJECTIVE: Obesity and high fat diet (HFD) consumption in rodents is associated with hypothalamic inflammation and reactive gliosis. While neuronal inflammation promotes HFD-induced metabolic dysfunction, the role of astrocyte activation in susceptibility to hypothalamic inflammation and diet-induced obesity (DIO) remains uncertain. METHODS: Metabolic phenotyping, immunohistochemical analyses, and biochemical analyses were performed on HFD-fed mice with a tamoxifen-inducible astrocyte-specific knockout of IKKß (GfapCreERIkbkbfl/fl, IKKß-AKO), an essential cofactor of NF-κB-mediated inflammation. RESULTS: IKKß-AKO mice with tamoxifen-induced IKKß deletion prior to HFD exposure showed equivalent HFD-induced weight gain and glucose intolerance as Ikbkbfl/fl littermate controls. In GfapCreERTdTomato marker mice treated using the same protocol, minimal Cre-mediated recombination was observed in the mediobasal hypothalamus (MBH). By contrast, mice pretreated with 6 weeks of HFD exposure prior to tamoxifen administration showed substantially increased recombination throughout the MBH. Remarkably, this treatment approach protected IKKß-AKO mice from further weight gain through an immediate reduction of food intake and increase of energy expenditure. Astrocyte IKKß deletion after HFD exposure-but not before-also reduced glucose intolerance and insulin resistance, likely as a consequence of lower adiposity. Finally, both hypothalamic inflammation and astrocytosis were reduced in HFD-fed IKKß-AKO mice. CONCLUSIONS: These data support a requirement for astrocytic inflammatory signaling in HFD-induced hyperphagia and DIO susceptibility that may provide a novel target for obesity therapeutics.

Startle suppression after mild traumatic brain injury is associated with an increase in pro-inflammatory cytokines, reactive gliosis and neuronal loss in the caudal pontine reticular nucleus.

Mild traumatic brain injury (mTBI) can produce somatic symptoms such as headache, dizziness, fatigue, sleep disturbances and sensorimotor dysfunction. Sensorimotor function can be measured by tests such as the acoustic startle reflex (ASR), an evolutionarily conserved defensive response to a brief yet sharp acoustic stimulus. mTBI produces a long-lasting suppression of ASR in rodents and humans; however, the mechanism of this suppression is unknown. The present study examined whether inflammatory processes in the brainstem (particularly the caudal pontine reticular nucleus, PnC) could account for the suppression of ASR after mTBI, because the PnC is an essential nucleus of the ASR circuit. Furthermore, while inflammation after mTBI is commonly observed in brain regions proximal to the site of impact (cortex and hippocampus), the effects of mTBI in brainstem structures remains largely understudied. The present study demonstrated a suppression of ASR one day after injury and lasting at least three weeks after an mTBI, replicating previous findings. Within the PnC, transient elevations of IL-1ß and TNF-α mRNA were observed at one day after injury, while IL-1α mRNA exhibited a delayed increase at three weeks after injury. Reactive gliosis (via IBA-1-ir for microglia and GFAP-ir for astrocytes) were also observed in the PnC, at one day and seven days after injury, respectively. Finally, the number of giant neurons (the major functional cell population in the PnC) was decreased three weeks after injury. The results indicate that glial activation precedes neuronal loss in the PnC, and correlates with the behavioral suppression of the ASR. The results also raise implications for brainstem involvement in the development of post-traumatic symptoms.