Transcriptional mutagenesis mediated by 8-oxoG induces translational errors in mammalian cells.

Reactive oxygen species formed within the mammalian cell can produce 8-oxo-7,8-dihydroguanine (8-oxoG) in mRNA, which can cause base mispairing during gene expression. Here we found that administration of 8-oxoGTP in MTH1-knockdown cells results in increased 8-oxoG content in mRNA. Under this condition, an amber mutation of the reporter luciferase is suppressed. Using second-generation sequencing techniques, we found that U-to-G changes at preassigned sites of the luciferase transcript increased when 8-oxoGTP was supplied. In addition, an increased level of 8-oxoG content in RNA induced the accumulation of aggregable amyloid ß peptides in cells expressing amyloid precursor protein. Our findings indicate that 8-oxoG accumulation in mRNA can alter protein synthesis in mammalian cells. Further work is required to assess the significance of these findings under normal physiological conditions.

Neural regeneration: role of traditional Chinese medicine in neurological diseases treatment.

The effects of a single compound and a mixture of traditional Chinese medicine (TCM) on promoting proliferation, differentiation, and migration of neural stem cells and regulating their microenvironment have been observed by Chinese scholars in recent years. These results showed good prospects in improving neural regeneration and repair of neurological disorders such as ischemic brain injury, Alzheimer's disease, Parkinson's disease, and depression. According to the TCM theory, the relationship between life of an individual and the disease was regarded as an entirety, and the theory emphasized the treatment based on syndrome differentiation since ancient times. In this paper, we attempted to introduce these medicines, which belong to natural products and have already been proved to possess clear therapeutic action on human bodies in the clinical setting. We summarized their effects promoting brain neurogenesis and repairing brain injuries in animal models and some mechanisms at the cellular and molecular levels.

Protective effects of octacosanol on 6-hydroxydopamine-induced Parkinsonism in rats via regulation of ProNGF and NGF signaling.

AIM: To investigate the protective effects of octacosanol in 6-hydroxydopamine-induced Parkinsonian rats and find whether octacosanol has effects on pro nerve growth factor (pro-NGF), NGF and the downstream effector proteins. METHODS: Behavioral tests, enzymatic assay, tyrosine hydroxylase immunohistochemistry, TUNEL and Western blot were used to investigate the effects of octacosanol in this rat model of PD. RESULTS: Oral administration of octacosanol (35-70 mg/kg, po for 14 d) significantly improved the behavioral impairments in rats induced by 6-OHDA and dose-dependently preserved the free radical scavenging capability of the striatum. Octacosanol treatment also effectively ameliorated morphological appearances of TH-positive neuronal cells in nigrostriatal systems and decreased the apoptotic cells induced by 6-OHDA in striatum. In addition, octacosanol strikingly blocked the 6-OHDA-induced increased expression of proNGF-p75NTR-sortilin death signaling complex and its downstream effector proteins. Meantime, octacosanol prevented the decreased levels of NGF, its receptors TrkA and p-Akt which together mediated the cell survival pathway. CONCLUSION: The findings implicated that the anti-parkinsonism effects afforded by octacosanol might be mediated by its neuro-microenvironment improving potency through retrieving the ratios of proNGF:NGF and the respective receptors p75NTR:TrkA in vivo. Due to its excellent tolerability and non-toxicity, octacosanol may be a promising agent for PD treatment.

[Relationship of oxidative DNA damage and expression of mitochondrial apoptotic proteins in rat striatum induced by 6-hydroxydopamine].

OBJECTIVE: To study the relationship between oxidative DNA damage and mitochondrial apoptosis relative proteins in rat striatum induced by 6-hydroxydopamine (6-OHDA) during the pathogenesis of Parkinson's disease (PD). METHODS: 6-OHDA was stereotactically injected into the bilateral right striatum of rats to produce PD models. Assays for 8-oxo-dG immunohistochemistry and Western blot for MTH1, Cytochrome c, Cl-caspase 9 and Cl-caspase 3 in right striatum was separately conducted. RESULTS: In 10 successful PD rats, compared with either sham or normal group, there were obvious more 8-oxo-dG positive cells in lesioned striatum while there was a lower expression of MTH1. Furthermore, the expressions of such intrinsic apoptotic pathway factors as cytoplasmic Cytochrome c, Cl-caspase 9 and Cl-caspase 3 were highly up-regulated in lesioned striatum. CONCLUSION: Oxidative DNA damage plays a key role in the pathogenesis of PD. Furthermore Cytochrome c, caspase 9 and caspase 3 are involved in the regulation of apoptosis under oxidative DNA damage induced by 6-OHDA.

Gossypium herbaceam extracts attenuate ibotenic acid-induced excitotoxicity in rat hippocampus.

Excitotoxicity is one of the most extensively studied processes of neuronal death and plays an important role in Alzheimer's disease. In the present study, the protective effects of Gossypium herbaceam extracts (GHE) on learning and memory impairment induced by excitatory neurotoxin ibotenic acid were examined in vivo using Morris water maze. Furthermore, neuroprotective effects of GHE were investigated with methods of immunohistochemistry and biochemistry. Our data showed that oral administration with GHE at the doses of 35, 70 and 140 mg/kg exerted an improved effect on the learning and memory impairment in rats induced by intracerebral injection of ibotenic acid. To confirm the precise mechanism of memory improvement by presence of GHE, we further investigated the potential protection on the hippocampus. Our findings suggest that GHE afforded a beneficial inhibition on pro-apoptosis proteins expression following ibotenic acid. Additionally, calcium pump activity and calbindin-D28k expression were dramatically increased after GHE treatment, implicating that the modulation of calcium homeostasis could be involved in the mechanism underlying neuroprotection of GHE against ibotenic acid-induced excitotoxicity. These data suggested that GHE could be a potential agent for preventing or retarding the development or progression of Alzheimer's disease.

Effects of hormone replacement therapy on magnetic resonance imaging of brain parenchyma hyperintensities in postmenopausal women.

AIM: To apply 3.0 magnetic resonance imaging (MRI) to study the effects of long-term, low dose hormone replacement therapy (HRT) on the brain parenchyma of postmenopausal women. METHODS: A total of 155 postmenopausal healthy female medical staff members from Peking Union Medical College Hospital were enrolled. The HRT group was composed of 71 subjects who had been given a low dose of HRT for over 4 years, while 84 women who had never been given HRT were enrolled in the control group. The Mini-Mental State Examination (MMSE) was used to evaluate mental state, and an Enzyme-Linked ImmunoSorbent Assay (ELISA) was used to detect plasma levels of sex hormones. In addition, all participants were subjected to an MRI, including axial T2 weighted imaging (T2WI), fluid-attenuated inversion recovery (FLAIR), T1 weighted imaging (T1WI, oblique coronal, vertical to the hippocampus, slice thickness 3 mm without gaps), and a 3D image of the whole brain. RESULTS: The ELISA showed that the plasma level of estradiol in the HRT group was significantly higher than that in the control group (P<0.05). No differences were observed in the MMSE between the two groups. In participants older than 70 years of age, the number of deep white matter hyperintensities (DWMHs) in the control group was significantly higher than that in the HRT group (P=0.0013); however, in other age subgroups, no statistical differences were observed. Finally, no significant difference in periventricular hyperintensity (PVH) between the two groups was observed. CONCLUSION: We found that a high plasma level of estradiol in postmenopausal women receiving long-term HRT was correlated with the survival of brain parenchyma.Acta Pharmacologica Sinica (2009) 30: 1065-1070; doi: 10.1038/aps.2009.81.

Gossypium herbaceam extracts inhibited NF-kappaB activation to attenuate spatial memory impairment and hippocampal neurodegeneration induced by amyloid-beta in rats.

Amyloid-beta (Abeta) is considered to be responsible for the pathogenesis of Alzheimer's disease. In the present study, the protective effect of Gossypium herbaceam extracts (GHE) on learning and memory impairment induced by Abeta were examined in vivo using Morris water maze and step through task. Furthermore, the antioxidant activity and neuroprotective effect of GHE was investigated with methods of histochemistry and biochemistry. These data showed that oral administration with GHE at the doses of 35, 70 and 140 mg/kg exerted an improved effect on the learning and memory impairment in rats induced by intracerebroventricular (i.c.v.) injection of 10 microg of Abeta(25-35). Subsequently, the GHE afforded a beneficial action on promotion on the activity of glutathione peroxidase and catalase, as well as inhibition on the NF-kappaB activation in the hippocampus followed by the presence of Abeta(25-35). Meanwhile, the number of degenerating neurons with an apoptotic feature was dramatically decreased in hippocampus after treatment with GHE, implicating that its antioxidant stress and inhibition of NF-kappaB activation could be involved in the mechanism underlying neuroprotection of GHE against Abeta-induced cell death. These findings suggested that GHE might be a potential agent for treatment of Alzheimer's disease.

Effects of long-term low-dose hormone replacement therapy on the binding capacity of platelet peripheral-type benzodiazepine receptor in postmenopausal women.

The effects of long-term low-dose hormone replacement therapy (HRT) on the level of hormone in plasma and on the binding capacity of peripheral-type benzodiazepine receptor (PBR) on the platelet membranes were investigated among women. This study was a retrospective and case-controlled study where 64 women using long-term low-dose HRT for over 4 years entered the study and 99 women, age and education matched, were enrolled as control. Plasma hormone level and platelet PBR binding capacity of two groups were analyzed. A significant increase in plasma estradiol level in women using HRT was observed, compared to those in the control group. Meanwhile, women in the HRT group displayed higher platelet PBR binding capacity. Further analysis demonstrated that the binding capacity of platelet PBR was closely related to estradiol plasma level in all subjects. These results suggest that long-term low-dose HRT could relieve the decrease of estradiol level in plasma and PBR binding capacity on platelets in postmenopausal women, alleviate the endocrine imbalance process, and might be beneficial for reducing the risks of some diseases.

Transplantation of human amniotic cells exerts neuroprotection in MPTP-induced Parkinson disease mice.

To determine the survival and differentiation of cultured Human amniotic cells (HACs) upon transplantation into the brain of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP)-induced Parkinson disease (PD) mice. Mouse model of PD was established with injections of MPTP (15 mg/kg, fourth, 2 h interval). After being labeled with PKH26, HACs isolated from human were transplanted into the striatum of PD mice. Immunohistochemistry was performed to evaluate the toxicity of MPTP in the substantia nigra, graft survival and endogenous neurogenesis. Brain-derived neurotrophic factor (BDNF) and glial cell line-derived neurotrophic factor (GDNF) level in the striatum were tested by ELISA. Our results showed that cultured HACs can express the marker of neural progenitor cells and differentiate into neuron, dopaminergic neuron, astrocyte and oligodendrocyte. TH-positive neural cells were significantly reduced in the substantia nigra in the model mice, whereas which increased in transplantation mice. Immunohistology results showed that transplanted HACs survived and migrated in the brain of PD model mouse, though no morphological integration was observed. BrdU-positive cells in the Subventricular zone (SVZ) and neurotrophins of the striatum increased in the transplantation mice. The results suggested that transplanted HACs could survive and promote the endogenous neurogenesis of mice, which maybe related to the increased level of neurotrophins of the striatum.

Effects of ning shen ling granule and dehydroepiandrosterone on cognitive function in mice undergoing chronic mild stress.

OBJECTIVE: To investigate the changes of spontaneous and cognitive behavior, and cholinergic M receptors in the brain of mice subjected to chronic mild stress (CMS), and to determine the effect of Ning Shen Ling Granule (NSL) and dehydroepiandrosterone (DHEA) on them. METHODS: CMS model mice were established by applying stress every day for 3 consecutive weeks with 7 kinds of unforeseeable stress sources, and they were medicated for 1 week beginning at the 3rd week of modeling. The changes in behavior were determined by Morris Water Maze and spontaneous movement test, and M-receptor binding activity in cerebral cortex, hippocampus and hypothalamus were measured by radioactive ligand assay with 3H-QNB. RESULTS: (1) The spontaneous movement in CMS model mice was significantly reduced, with the latency for searching platform in Morris Water Maze obviously prolonged (P<0.01), and these abnormal changes in behavior were improved in those treated with NSL and DHEA. (2) The binding ability of M-receptor in cerebral cortex and hippocampus of CMS mice was significantly decreased as compared with those in the control group (P<0.05), but could be restored to the normal level after intervention with NSL or DHEA. CONCLUSION: The decline of spontaneous movement and spatial learning and memory ability could be induced in animals by chronic mild stress, and that may be related to the low activity of central cholinergic M-receptors. Both NSL and DHEA could effectively alleviate the above-mentioned changes.

Evaluation of neuroprotective effects of long-term low dose hormone replacement therapy on postmenopausal women brain hippocampus using magnetic resonance scanner.

OBJECTIVE: To investigate the effects of long-term low dose hormone replacement therapy (HRT) on postmenopausal women in hormone level, cognition score, hippocampus volume, and magnetic resonance spectroscopy (MRS) parameters. METHODS: A total of 182 postmenopausal women aged 50-87 years were chosen at Peking Union Medical College Hospital and assigned to HRT group and control group. The volunteers of HRT group had taken low dose hormone [estradiol (E2) 0.5-1.0 mg and progesterone 0.5-2.0 mg, once a day] for 4-33 years. The concentrations of E2, progesterone, and testosterone were measured using enzyme-linked immunosorbent assay (ELISA). The gene types of apolipoprotein E (ApoE) were measured by polymerase chain reaction, and the subjects with susceptible genes (ApoE epsilon3/epsilon4) of Alzheimer's disease (AD) were screened. Their hippocampus volumes and MRS parameters were obtained through magnetic resonance imaging (MRI), and results in two groups were analyzed by statistical method. RESULTS: Compared with control group, the concentrations of E2 at each age stage in HRT group were significantly higher (P < 0.05) except the 80-89 years old subgroup; yet, there were no statistical differences in the concentrations of progesterone and testosterone between the two groups. There was no obvious difference in ApoE subtypes distribution between the two groups. The results of hippocampus MRI for the subjects with susceptible genes ApoE epsilon3/epsilon4 (HRT group 14 cases, control group 11 cases) showed that the ratio of bilateral hippocampus volume to whole brain volume in HRT group (0.406 +/- 0.028) was significantly higher than control group (0.369 +/- 0.031, P < 0.05). The results of 1H MRS for the subjects with susceptible genes ApoE epsilon3/epsilon4 (HRT group 12 cases, control group 11 cases) showed that the N-acetylaspartate/total creatine at the area of hippocampus in HRT group (1.54 +/- 0.08) were significantly higher than control group (1.45 +/- 0.13, P < 0.05). CONCLUSIONS: For postmenopausal women, long-term low dose HRT can maintain the physiological concentration of E2 in plasma. Furthermore, the hippocampus MRI performed on those with ApoE epsilon3/epsilon4 genes shows that long-term low dose HRT can prevent hippocampus atrophy, which is beneficial to maintain the brain function and prevent AD.

[Effects of midazolam on muscarinic receptor of brain in healthy and scopolamine-treated rats].

OBJECTIVE: To investigate the recent and permanent effects of pretreatment with midazolam on muscarinic receptor of brain in healthy and scopolamine-treated rats. METHODS: (1) In recent effect group, thirty-eight male SD rats were randomly divided into 4 groups: control group (Con, n=9), midazolam group (Mid, n=9), scopolamine group (Sco, n=10), midazolam+scopolamine group (Mid+sco, n=10). On the 1st, 2nd, and 3rd days, Mid group and Mid+sco groups were treated with intraperitoneal injection of 50 mg/kg midazolam per day while Con group and Sco group were treated with intraperitoneal injection of the same voluminal physiological saline per day. On the 4th, 5th, and 6th days, Scopolamine 0.8 mg/kg intraperitoneal injection per day was administered in Sco group and Mid+sco group while same voluminal physiological saline was administered in Con group and Mid group. (2) In permanent effect group, thirty-six male SD rats were randomly divided into 4 groups: control group (Con, n=9), midazolam group (Mid, n=9), scopolamine group (Sco, n=9), midazolam+scopolamine group (Mid+sco, n=9). On the 1st, 2nd, and 3rd days, Mid group and Mid+sco group were treated with intraperitoneal injection of 50 mg/kg midazolam per day while Con group and Sco group were treated with intraperitoneal injection of the same voluminal physiological saline per day. On the 10th, 11th, and 12th days, Scopolamine 0.8 mg/kg intraperitoneal injection per day was administered in Sco group and Mid+sco group while the same voluminal physiological saline was administered in Con group and Mid group. (3)Then the rats was decapitated and the cerebra cortex and hippocampus were removed. The binding capacity of muscarinic receptor with [3H] QNB were determined. Bmax and Kd of muscarinic receptor in hippocampus were determined by Scatchard analysis in recent effect group. RESULTS: (1) In recent effect group: the binding capacity of muscarinic receptor in hippocampus was significantly higher in Con group than in Mid group, Sco group and Mid+sco group (P<0.01), which was also higher in Mid group than in Sco group (P<0.05) and Mid+sco group (P<0.01), higher in sco group than in Mid+sco group (P<0.01). Kd of muscarinic receptor in hippocampus in Sco group and Mid group were higher than in Con group and Mid+sco group (P<0.01). Bmax of muscarinic receptor in hippocampus was significantly higher in Con group than in Mid group (P<0.05), Sco group and Mid+sco group (P<0.01), which was also higher in Mid group than in Sco group and Mid+sco group (P<0.01), higher in sco group than in Mid+sco group (P<0.05). There was no significant difference of the binding capacity of muscarinic receptor in cortex. (2) In permanent effect group: the binding capacity of muscarinic receptor in hippocampus was significantly higher in Con group and Mid group than in Sco group and Mid+sco group (P<0.01). There was no significant difference of the binding capacity of muscarinic receptor in cortex. CONCLUSION: Pretreatment with intraperitoneal injection of 50 mg/kg midazolam for three days had no effect on muscarinic receptor of cortex, but could induce the binding capacity of muscarinic receptor with [3H] QNB and change the density and affinity of muscarinic receptor in hippocampus in healthy and scopolamine-treated rats, yet the changes were not permanent.

[Effect of lidocaine on the impairment of learning and memory function and central cholinergic system after transient global cerebral ischemia in mice].

OBJECTIVE: To evaluate the effects of lidocaine on the impairments of learning and memorial function and central cholinergic system after transient global cerebral ischemia in mice of different apolipoprotein E genotypes. METHODS: Transient global ischemia was induced by bilateral common carotid arteries occlusion (BCCAO) for 17 minutes. Healthy male C57BL/6J wild-type mice (C57 mice) and apolipoprotein E knockout mice (ApoE mice) were randomly divided into six groups: C57 control group (sham operation, neither BCCAO was performed nor pharmacologic intervention was given), C57 ischemia group (BCCAO for 17 minutes was performed and normal saline was given intraperitoneally), C57 lidocaine group (BCCAO for 17 minutes was performed and lidocaine was given intraperitoneally), ApoE control group (the same procedure as that of C57 control group), ApoE ischemia group (the same procedure as that of C57 ischemia group), ApoE lidocaine group (the same procedure as that of C57 lidocaine group). The mice were allowed to recover for 7 days. Morris water maze test were performed from the 8th postoperative day. Mice were tested four times daily for 5 consecutive days. The latency periods were recorded and the percentages of effective search strategies were calculated. On the 12th postoperative day after Morris water maze test, mice were decapitated under anesthesia. The cerebral cortex and hippocampus were removed quickly. The activities of acetylcholinesterase (AChE) and choline acetyltransferase (ChAT) as well as the binding activity of muscarinic receptor (M receptor) were assayed. RESULTS: (1) The latency periods were significantly longer in the ischemia groups than in the corresponding control groups (P<0.05 or 0.01). They were also significantly longer in C57 lidocaine group than in C57 ischemia group [on the 3rd day of test, (74.1+/-32.7)s vs (49.2+/-19.5)s] (P<0.05). However, they were significantly shorter in apoE lidocaine group than in apoE ischemia group [from the 3rd to the 5th days of test, (40.7+/-27.7)s vs (84.7+/-26.8)s, (31.2+/-19.2)s vs (72.1+/-33.0)s, and (28.0+/-22.1)s vs (60.8+/-26.9)s, respectively] (P<0.05 or 0.01). When compared between two strains, they were significantly longer in apoE ischemia group than in C57 ischemia group (P<0.05 or 0.01). However, they were significantly shorter in apoE lidocaine group than in C57 lidocaine group (P<0.01). (2) The percentages of effective search strategies were significantly lower in the ischemia groups than in the corresponding control groups (P<0.01). They were also significantly lower in C57 lidocaine group than in C57 ischemia group [from the 3rd to the 5th days of test, (18.2+/-11.7)% vs (41.7+/-17.7)%, (22.7+/-20.8)% vs (55.6+/-20.8)%, and (29.6+/-27.0)% vs (66.7+/-21.7)%, respectively] (P<0.01). However, they were significantly higher in apoE lidocaine group than in apoE ischemia group [from the 3rd to the 5th days of test, (41.7+/-25.8)% vs (15.6+/-12.9)%, 8.3+/-20.4)% vs (18.8+/-11.6)%, and (66.7+/-30.3)% vs (28.1+/-20.9)%, respectively] (P<0.01). When compared between two strains, they were significantly lower in apoE ischemia group than in C57 ischemia group (P<0.01). However, they were significantly higher in apoE lidocaine group than in C57 lidocaine group (P<0.01). (3) The parameters of central cholinergic system were significantly lower in the ischemia groups than in the corresponding control groups (P<0.05 or 0.01). They were also significantly lower in C57 lidocaine group than in C57 ischemia group [the activities of AChE of cerebral cortex and hippocampus, (0.44+/-0.09) U/mg protein vs (0.57+/-0.08) U/mg protein, and (0.73+/-0.21) U/mg protein vs (1.08+/-0.27) U/mg protein, respectively; the activities of ChAT of hippocampus, (80.60+/-6.55) pmol/mg protein/min vs (93.66+/-11.15) pmol/mg protein/min; and the binding activities of M receptor of cerebral cortex and hippocampus, (6.03+/-0.74) pmol/mg protein vs (7.49+/-0.48) pmol/mg protein, and (7.56+/-0.92) pmol/mg protein vs (10.65+/-3.35) pmol/mg protein, respectively] (P< 0.05 or 0.01). However, they were significantly higher in ApoE lidocaine group than in ApoE ischemia group [the activities of ChAT of cerebral cortex and hippocampus, (66.99+/-7.55) pmol/mg protein/min vs (46.23+/-4.96) pmol/mg protein/min, and (116.46+/-24.05) pmol/mg protein/min vs (92.08+/-16.33) pmol/mg protein/min, respectively] (P<0.05 or 0.01). When compared between two strains, they were significantly higher in ApoE lidocaine group than in C57 lidocaine group (P< 0.05 or 0.01). CONCLUSION: Transient global cerebral ischemia caused significant brain damages in both strains of mice, which were represented by decline of learning and memorial function and damage of the central cholinergic system. Compared with the C57 mice, the ApoE mice had enhanced susceptibility to global cerebral ischemic injury as shown by more severe decline of the learning and memorial function. In the C57 mice, lidocaine significantly worsened the ischemic brain damage. In the ApoE mice, however, lidocaine significantly alleviated the ischemic cerebral results.

[Correlation of changes of peripheral benzodiazepine receptors in hippocampus synaptosomes with cognitive impairment: experiment with D-galactose-induced senescent rats].

OBJECTIVE: To investigate the effects of peripheral benzodiazepine receptor (PBR) in hippocampus synaptosomes on spatial learning and memory. METHODS: Twenty-four Sprague-Dawley rats of both sexes were randomly divided into 2 equal groups: D-galactose-treated group, receiving subcutaneous injection of D-galactose 100 mg/kg once a day for 56 days, and normal saline (NS) control group, receiving comparable injections of NS. Spatial learning and memory were assessed by Morris water maze test for 5 days. After the behavioral testing all rats were decapitated and the hippocampus was removed immediately. Then, the synaptosomes in hippocampus were purified by density gradient centrifugation. The PBR binding parameters, maximal binding site density (B(max)) and equilibrium dissociation constant (KD), were estimated by radioligand [(3)H] PK11195 binding assays. RESULTS: Two weeks after the beginning of experiment the D-galactose-treated rats began to show symptoms of aging. On the 5th day of behavioral testing the D-galactose-induced aging rats presented significant impairment in water maze performance compared with the NS controls (P < 0.001). The decrease in specific [(3)H] PK11195 binding in the hippocampus synaptosomes of the D-galactose-treated group was 67.3 +/- 18.6 fmol/mg, significantly lower than that of the saline control group (127.9 +/- 20.1 fmol/mg, P < 0.01). The Scatchard analysis revealed that the B(max) of the D-galactose-treated group was 177.2 +/- 26.7 fmol/mg, significantly lower than that of the saline group (296.7 +/- 33.5 fmol/mg, P < 0.01), and the K(D) of the D-galactose-treated group was 0.503 +/- 0.06 nmol/L, not significantly different from that of the saline control group (0.502 +/- 0.05 nmol/L). Correlation analysis showed that the specific [(3)H] PK11195 binding in hippocampus synaptosomes was closely related to the escaping latency (r = -0.854), swimming time (r = 0.845), and distance (r = 0.851) in platform quadrant in Morris water maze in all rats (all P < 0.001). CONCLUSION: The decreased expression of PBR in hippocampus synaptosomes is possibly associated with the spatial learning-memory impairments induced by D-galactose.

M2 Macrophage Transplantation Ameliorates Cognitive Dysfunction in Amyloid-ß-Treated Rats Through Regulation of Microglial Polarization.

Alzheimer's disease (AD) is the most common neurodegenerative disorder in the elderly population. Neuroinflammation induced by amyloid-ß (Aß) aggregation is considered to be the critical factor underlying AD pathological mechanisms. Alternatively activated (M2) macrophages/microglia have been reported to have neuroprotective effects in neurodegenerative disease. In this study, we characterized the neuroprotective effects of M2 macrophage transplantation in AD model rats and investigated the underlying mechanisms. Intracerebroventricular injection of Aß1 - 42 to rats was used to model AD and resulted in cognitive impairment, neuronal damage, and inflammatory changes in the brain microenvironment. We observed an increased interferon regulatory factor (IRF) 5/IRF4 ratio, resulting in greater production of classically activated (M1) versus M2 microglia. M2 macrophage transplantation attenuated inflammation in the brain, reversed Aß1 - 42-induced changes in the IRF4-IRF5 ratio, drove endogenous microglial polarization toward the M2 phenotype, and ameliorated cognitive impairment. Nerve growth factor (NGF) treatment reduced the IRF5/IRF4 ratio and induced primary microglial polarization to the M2 phenotype in vitro; these effects were prevented by tyrosine Kinase Receptor A (TrkA) inhibition. M2 macrophage transplantation restored the balance of IRF4-IRF5 by affecting the expression of NGF and inflammatory cytokines in the brains of AD model rats. This drove microglial polarization to the M2 phenotype, promoted termination of neuroinflammation, and resulted in improved cognitive abilities.

Effect of Chinese herbal compound Naofucong () on the inflammatory process induced by high glucose in BV-2 cells.

OBJECTIVE: To determine the effect of medicated serum of Chinese herbal compound Naofucong (, NFC) on the microglia BV-2 cells viability and the transcription and expression of interleukin-6 (IL-6) and tumor necrosis factor α (TNF-α) in microglia BV-2 cells to further explore the mechanisms underlying the protective effect of NFC on inflammatory process induced by high glucose. METHODS: The microglia BV-2 cells incubated in vitro were divided into different groups: the control group (25 mmol/L glucose), the model group (75 mmol/L glucose), high glucose media containing different dose medicated serum of NFC. After being cultured for 24 h, changes in IL-6 and TNF-α were measured by quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assay. The expression of surface marker CD11b of activated microglia was measured by confocal laser scanning microscope and Western blot. Nuclear factor-κB (NF-κB) p-p65 expression was analyzed by Western blot. RESULTS: The model group obviously increased the expression of microglial surface marker CD11b and NF-κB p-p65 (all P<0.01), induced a signifificant up-regulation of release and the mRNA expression of IL-6 and TNF-α (P<0.01 or P<0.05). The medicated serum of NFC could obviously down-regulate the transcription and expression of surface marker CD11 b and NF-κB p-p65 (all P<0.01), and inhibit the mRNA and protein expression (P<0.01 or P<0.05) of inflflammatory cytokines, such as IL-6 and TNF-α, in microglia BV-2 cells cultured with high glucose for 24 h. CONCLUSIONS: The inhibition of microglial activation and IL-6 and TNF-α expression induced by high glucose may at least partly explain NFC therapeutic effects on diabetes-associated cognitive decline diseases. Its underlying mechanism could probably be related to the inhibition of NFC on NF-κB phosphorylation.

[Effects of acidic oligose on differentially expressed genes in the mice model of Alzheimer's disease by microarray].

AIM: To investigate the molecular mechanism of protective effect of acidic oligose 971 on Alzheimer's disease mouse model by using microarray. METHODS: Balb/c mice were randomly divided into control group, beta-AP(25-35) i.c.v. injected group and 971-treated group. The learning-memory ability of mice was tested by Morris water maze experiment. Total RNA of the cerebral cortex was extracted from the mice of each group. cDNA microarrays containing 1176 genes were used to investigate the gene expression pattern of each group. Expressions of 5 genes were randomly selected for further confirmation by RT-PCR. RESULTS: Icv injection of beta-AP(25-35) caused significant impairments in spatial and working memory performances of mice in Morris water maze and which were relieved by the treatment of 971. Up- and down- regulated genes were 19 and 12 in beta-AP(25-35)-injected group vs control group, respectively. Up- and down- regulated genes were 13 and 4, respectively, in 971-treated group vs beta-AP(25-35)-injected group. RT-PCR results indicated that 5 genes showed identical results to that of the microarray. CONCLUSION: The protective effect of 971 on learning and memory ability of beta-AP(25-35)-treated mouse may be related to the expression changes of genes involved in cell cycle, DNA repair, nerve growth, synaptic plasticity and immune response, etc.

[Effects of lidocaine on impairment of learning and memory function and cholinergic system caused by cerebral microsphere embolism in rats].

OBJECTIVE: To investigate the effects of lidocaine on impairment of learning and memory function and cholinergic system caused by cerebral microsphere embolism in rats. METHODS: Healthy male Wister rats were randomly divided into the following groups. (1) Control group. (2) 600 microsphere group and 900 microsphere group, in which 600 or 900 microspheres were injected into the right internal carotid artery, respectively. (3) 600 treatment group and 900 treatment group, in which 600 or 900 microspheres were injected into the right internal carotid artery, respectively, and lidocaine was given. Water maze tasks were tested for 5 consecutive days from the 7th postoperative day. The rats were then decapitated and regions of cerebral cortex, hippocampus, and striatum were selected. The activities of choline acetyltransferase and cholinesterase and the binding activity of muscarinic receptor were determined. RESULTS: (1) The latency periods were significantly longer in the 900 microsphere group than in the control group and in the 600 microsphere group. (2) The percentages of effective search strategy were significantly lower in the 600 and 900 microsphere groups than in the control group. They were significantly higher in the 600 and 900 treatment groups than in the corresponding microsphere groups. (3) The activities of choline acetyltransferase of cerebral cortex were significantly lower in the 900 microsphere and two treatment groups than in the control group. They were also significantly lower in the 600 and 900 treatment groups than in the corresponding microsphere groups. Those of striatum were all significantly lower in the microsphere and treatment groups than in the control group. (4) The activities of cholinesterase of cerebral cortex were significantly lower in the 900 microsphere group than in the control and 600 microsphere groups. They were significantly higher in the 900 treatment group than in the 900 microsphere group. Those of hippocampus were all significantly lower in the microsphere and treatment groups than in the control group. (5) The binding activities of muscarinic receptor of cerebral cortex were significantly lower in the 900 microsphere and two treatment groups than in the control group. They were also significantly lower in the two treatment groups than in the corresponding microsphere groups. Those of hippocampus and striatum were all significantly lower in the microsphere and treatment groups then in the control group. They were also significantly lower in the 600 or 900 treatment group than in the corresponding microsphere group. CONCLUSION: Cerebral microsphere embolism caused significant and quantity-dependent impairment of learning and memory function and cholinergic system in rats. Lidocaine alleviated learning and memory dysfunction caused by cerebral microsphere embolism, but further inhibited the parameters of central cholinergic system.

Lactulose enhances neuroplasticity to improve cognitive function in early hepatic encephalopathy.

Lactulose is known to improve cognitive function in patients with early hepatic encephalopathy; however, the underlying mechanism remains poorly understood. In the present study, we investigated the behavioral and neurochemical effects of lactulose in a rat model of early hepatic encephalopathy induced by carbon tetrachloride. Immunohistochemistry showed that lactulose treatment promoted neurogenesis and increased the number of neurons and astrocytes in the hippocampus. Moreover, lactulose-treated rats showed shorter escape latencies than model rats in the Morris water maze, indicating that lactulose improved the cognitive impairments caused by hepatic encephalopathy. The present findings suggest that lactulose effectively improves cognitive function by enhancing neuroplasticity in a rat model of early hepatic encephalopathy.

Neuroprotective effects of Aceglutamide on motor function in a rat model of cerebral ischemia and reperfusion.

PURPOSE: To investigate the effect and underlying mechanism of Aceglutamide on motor dysfunction in rats after cerebral ischemia-reperfusion. METHODS: Adult male Sprague-Dawley rats were subjected to 2 h transient middle cerebral artery occlusion (MCAO). Aceglutamide or vehicle was intraperitoneally given to rats at 24 h after reperfusion and lasted for 14 days. Subsequently functional recovery was assessed and number of tyrosine hydroxylase (TH)-positive neurons in substantia nigra (SN) was analyzed. Tumor necrosis factor receptor-associated factor 1(TRAF1), P-Akt and Bcl-2/Bax were determined in mesencephalic tissue by Western blot method. PC12 cells and primary cultured mesencephalic neurons were employed to further investigate the mechanism of Aceglutamide. RESULTS: Aceglutamide treatment improved behavioral functions, reduced the infarction volume, and elevated the number of TH-positive neurons in the SN. Moreover, Aceglutamide significantly attenuated neuronal apoptosis in the SN. Meanwhile Aceglutamide treatment significantly inhibited the expression of TRAF1 and up-regulated the expression of P-Akt and Bcl-2/Bax ratio both in vitro and in vivo. CONCLUSIONS: Aceglutamide ameliorated motor dysfunction and delayed neuronal death in the SN after ischemia, which involved the inhibition of pro-apoptotic factor TRAF1 and activation of Akt/Bcl-2 signaling pathway. These data provided experimental information for applying Aceglutamide to ischemic stroke treatment.