SELENOK-dependent CD36 palmitoylation regulates microglial functions and Aß phagocytosis.

Amyloid-beta (Aß) is a key factor in the onset and progression of Alzheimer's disease (AD). Selenium (Se) compounds show promise in AD treatment. Here, we revealed that selenoprotein K (SELENOK), a selenoprotein involved in immune regulation and potentially related to AD pathology, plays a critical role in microglial immune response, migration, and phagocytosis. In vivo and in vitro studies corroborated that SELENOK deficiency inhibits microglial Aß phagocytosis, exacerbating cognitive deficits in 5xFAD mice, which are reversed by SELENOK overexpression. Mechanistically, SELENOK is involved in CD36 palmitoylation through DHHC6, regulating CD36 localization to microglial plasma membranes and thus impacting Aß phagocytosis. CD36 palmitoylation was reduced in the brains of patients and mice with AD. Se supplementation promoted SELENOK expression and CD36 palmitoylation, enhancing microglial Aß phagocytosis and mitigating AD progression. We have identified the regulatory mechanisms from Se-dependent selenoproteins to Aß pathology, providing novel insights into potential therapeutic strategies involving Se and selenoproteins.

p38 and ERK1/2-Dependent Activation of c-Jun Is Required for the Downregulation of Oxidative Stress-Induced ERα in Hypothalamic Astrocytes.

INTRODUCTION: Gonadotropin-releasing hormone (GnRH) is a hypothalamic neuropeptide that plays important roles in the female fertility. Accumulating evidence suggests that ERα present in the astrocytes of the hypothalamus region is essential for production of GnRH. The astrocytes display age-related senescence associated to oxidative stress induced by the estrogen metabolites. However, it is still unclear whether and how ERα expression changes during astrocyte aging. METHODS: Immunofluorescence was performed to analyze the ERα gene levels in hypothalamic astrocytes of naturally aging C57BL/6J female mice. We employed an oxidative stress cell model receiving 2-hydroxyestradiol (2OH-E2) intervention to confirm the downregulation of ERα expression in primary astrocytes. Western blot analysis was used to explore which oxidative stress signaling pathways induced loss of the ERα gene. Finally, ChIP-qPCR was employed to evaluate whether the c-Jun protein is able to regulate ERα gene expression. RESULTS: Compared to young mice, we found that the ERα expression of mid-aged mice was significantly decreased. In hypothalamic astrocytes, 2OH-E2 treatment significantly reduced the expression of the ERα gene. Moreover, we observed that transcription factor c-Jun could directly inhibit transcriptional ERα gene expression and might also reduce it by decreasing H3K27 acetylation at promoter regions. Administration of the antioxidants Rg1 and astaxanthin significantly attenuated the decrease in ERα gene expression induced by oxidative stress. CONCLUSIONS: The current data demonstrate that oxidative stress leads to loss of ERα involving the activation of the p38 and ERK1/2 pathways and the induction of the c-Jun protein in hypothalamic astrocytes. C-Jun protein regulates ERα gene expression via direct transcriptional repression or involving histone acetylation modifications at ERα gene promoter sites.

Polygonatum sibiricum ameliorated cognitive impairment of naturally aging rats through BDNF-TrkB signaling pathway.

Cognitive dysfunction is high in the elderly population and seriously affects the quality of life. Brain-derived neurotrophic factor (BDNF) is one of the key neurotrophic proteins, and activation of BDNF-TrkB is considered an effective strategy to improve cognitive dysfunction during aging. In this study, administration of polygonatum sibiricum (PS) for 5 months effectively ameliorates the cognitive function, improving the Nissl body state in cortex and hippocampus in aging rats. In addition, PS can improve the synaptic structure and increase the number of synapses. Furthermore, PS reverses the reduction of synaptic plasticity-related proteins postsynaptic density protein 95 (PSD-95) and synaptophysin during aging and up-regulates the expression of BDNF-TrkB. In conclusion, PS improves cognitive dysfunction and enhances synaptic plasticity in naturally aged rats by regulating the BDNF-TrkB signaling pathway. PS has the potential to be developed as a novel and promising functional health food for the elderly. PRACTICAL APPLICATIONS: Polygonatum sibiricum (PS) is a traditional Chinese medicine, which has been included in the homologous plant of medicine and food. PS has been widely used to treat lung diseases, diabetes and antiaging in clinical. Studies have confirmed that PS can accelerate the repair and regeneration of damaged neurons, reverse the changes in synaptic structure, and improve the ability of learning and memory. Our study confirmed that PS significantly improved the cognitive function in aging rats. PS has great potential to be developed as a functional food for improving neurological function and anti-aging.

Recurrence Outcome in Hepatocellular Carcinoma within Milan Criteria Undergoing Microwave Ablation with or without Transarterial Chemoembolization.

Background and Objectives: The recurrence outcome in patients who underwent microwave ablation (MWA) with or without transarterial chemoembolization (TACE) for hepatocellular carcinoma (HCC) within Milan criteria remains unclear. The aim of this retrospective study was to identify the predictive factors of recurrence in these patients. Materials and Methods: From May 2018 to April 2021, 66 patients with HCC within Milan criteria were enrolled. Local tumor progression (LTP) and recurrence-free survival (RFS) were evaluated. Univariate and multivariate analyses were used to evaluate the risk factors of recurrence. The propensity score analysis was conducted to reduce potential confounding bias. Results: During the median follow-up of 25.07 months (95% confidence interval [CI], 21.85, 28.28), the median time to LTP and RFS were 20.10 (95%CI, 14.67, 25.53) and 13.03 (95%CI, 6.36, 19.70) months. No group difference (MWA vs. MWA + TACE) was found in 1-year cumulative LTP (p = 0.575) and RFS (p = 0.515), but meaningful significant differences were found in two-year recurrence (LTP, p = 0.007 and RFS, p = 0.037). Univariate and multivariate analyses revealed that treatment received before ablation was an independent risk factor of LTP (hazard ratio [HR] 4.37, 95%CI, 1.44, 13.32) and RFS (HR 3.41, 95%CI, 1.49, 7.81). Conclusions: The LTP and RFS in the MWA group were similar to that in the MWA combined with TACE. For HCC within Milan criteria, both groups preferentially selected MWA. More endeavor and rigorous surveillance should be taken to relapse prevention, in patients who have received previous treatment.

Effects of dietary nucleotides on growth performance, immune response, intestinal morphology and disease resistance of juvenile largemouth bass, Micropterus salmoides.

An 8 week feeding trial was carried out to investigate the effects of dietary nucleotides on growth performance, intestinal morphology, immune response and disease resistance of juvenile largemouth bass, Micropterus salmoides. Five grades of dietary nucleotide levels were designed as 0, 0.2, 0.4, 0.8 and 1.2 g kg-1 , respectively. Each group had 3 replicates, with 40 fish in each replicate. After the feeding experiment, 15 fish from each tank were infected with Aeromonas hydrophila for 14 days. The results indicated that fish fed the diets containing 0.4, 0.8 and 1.2 g kg-1 nucleotides had higher growth performance and feed utilization than those fed the control diet. Nonetheless, there were no significant differences in survival between all the groups, although fish fed the diets with all-level nucleotides obtained higher survival than those fed the control diet. Dietary nucleotides significantly affected the superoxide dismutase, acid phosphatase and catalase activities in serum but not the malondialdehyde content. Fish fed the 0.4 g kg-1 nucleotide diets had the highest fold height, enterocyte height and muscular layer thickness significantly. The average mortality of largemouth bass infected with A. hydrophila was significantly influenced by dietary nucleotides. The mortality was significantly higher in the control group (91.11%) and 0.02% nucleotide group (73.11%) followed by the other groups and lowest in the 0.8 g kg-1 nucleotide group. In summary, dietary 0.4-0.8 g kg-1 nucleotides promoted growth performance, enhanced immunity and improved intestinal morphology and disease resistance of largemouth bass.

Clinical efficacy of Shugan granule in the treatment of mixed anxiety-depressive disorder: A multicenter, randomized, double-blind, placebo-controlled trial.

ETHNOPHARMACOLOGICAL RELEVANCE: Shugan granule is derived from Xiaoyao powder, a traditional Chinese medicine that has been shown to be effective in treating emotional disorders. At present, there is no standard drug treatment for mixed anxiety-depressive disorder (MADD), and no evidence-based clinical trial has been performed for any drug, meaning MADD patients are unable to obtain standardized treatment. AIM OF THE STUDY: The purpose of this clinical trial was to test the clinical efficacy and safety of Shugan granules in the treatment of MADD, and to provide clinical trial-based support along with drug recommendations for the treatment of MADD. MATERIALS AND METHODS: A multicenter, randomized, double-blind, placebo-controlled study was conducted on 400 patients with MADD recruited from January 1, 2019 to December 31, 2020, and they were randomly divided into test and placebo groups with a 1:1 ratio. Subjects in the test group (n = 200) received oral administration of Shugan granules, while subjects in the placebo group (n = 200) received oral administration of a Shugan granule simulator. The treatment lasted for 8 weeks. The Hamilton Anxiety Scale (HAMA), Hamilton Depression Scale-17 (HAMD-17), Clinical Global Impression Scale (CGIS), Self-rating Anxiety Scale (SAS), and Self-rating Depression Scale (SDS) were used to evaluate efficacy. In addition, the traditional Chinese medicine (TCM) syndrome scale for MADD was developed to observe improvements of related symptoms in patients after treatment based on the disease guidelines of TCM and the clinical manifestations of depression. Furthermore, the safety of Shugan granules was evaluated during and after treatment. RESULTS: After 8 weeks of treatment, the total scores for HAMA, HAMD, SAS, and SDS in the test group were significantly lower than those in the placebo group (P < 0.01). The proportion of patients with efficacy index (EI) > 1 for the CGIS score in the test group was significantly higher than that in the placebo group (P < 0.01). The efficacy of treatment in the test group based on the TCM syndrome scale was 70.16% and 88.27% after 4 weeks and 8 weeks, respectively, which was significantly higher than that in the placebo group (44.27% and 66.67% after 4 weeks and 8 weeks, respectively; P < 0.01). The disappearance rate of single symptoms in the test group was 20-30% higher than that in the placebo group, with a significant difference between groups (P < 0.05). During the treatment period, the incidence of adverse reactions was 2.05% in the test group and 2.06% in the placebo group, with no significant differences noted (P = 1.0000). CONCLUSION: Shugan granule was more effective than placebo in the treatment of MADD. Moreover, there was no significant difference between the two groups in terms of safety. This paper provides a clinical therapeutic regime using Shugan granule for the treatment of MADD.

APOE4 genotype exacerbates the depression-like behavior of mice during aging through ATP decline.

Population-based studies reveal that apolipoprotein E (APOE) ε4 gene allele is closely associated with late-life depression (LLD). However, its exact role and underlying mechanism remain obscure. The current study found that aged apoE4-targeted replacement (TR) mice displayed obvious depression-like behavior when compared with age-matched apoE3-TR mice. Furthermore, apoE4 increased stress-induced depression-like behaviors, accompanied by declines in the hippocampal 5-HT (1A) radioligand [18F] MPPF uptake evidenced by positron emission tomography (PET). In [18F]-fluorodeoxyglucose PET ([18F]-FDG PET) analyses, the FDG uptake in the prefrontal cortex, temporal cortex and hippocampus of apoE4-TR mice significantly declined when compared with that of apoE3-TR mice after acute stress. Further biochemical analysis revealed that ATP levels in the prefrontal cortex of apoE4-TR mice decreased during aging or stress process and ATP supplementation effectively rescued the depression-like behaviors of elderly apoE4-TR mice. In primary cultured astrocytes from the cortex of apoE-TR mice, apoE4, when compared with apoE3, obviously decreased the mitochondrial membrane potential, mitochondrial respiration, and glycolysis in a culture time-dependent manner. Our findings highlight that apoE4 is a potential risk factor of depression in elderly population by impairing the glucose metabolism, reducing ATP level, and damaging mitochondrial functions in astrocytes, which indicates that in clinical settings ATP supplementation may be effective for elderly depression patients with apoE4 carrier.

The Effects of Early Oropharyngeal Administration of Microdosed Colostrum on Feeding Status in Ventilated Extremely Low-Birth-Weight Infants.

Background: For extremely low-birth-weight infants (ELBWIs), mechanical ventilation and total parenteral nutrition are generally required in the early stages and lose the protective effect of early gastrointestinal nutrition of colostrum. We conducted a prospective randomized controlled trial to explore the effectiveness of early colostrum oropharyngeal administration on the feeding status of ELBWIs on mechanical ventilation. Materials and Methods: We randomly divided mechanically ventilated ELBWIs into an intervention group and a control group. In the intervention group, we provided oropharyngeal administration of colostrum during mechanical ventilation. The first colostrum oropharyngeal administration ended within 24 hours of birth. In the control group, we gave colostrum only for gastrointestinal nutrition, and other interventions were the same as for the intervention group. We collected the 1st and 6th day of life airway secretions and urine specimens from both groups. We recorded feeding status, including corrected gestational age at onset of enteral nutrition, corrected gestational age of no gastric retention during feeding, corrected gestational age of full enteral nutrition, corrected gestational age of sucking began, and corrected gestational age of per oral feeding. We also recorded growth of body mass, the incidence of feeding intolerance, and necrotizing enterocolitis (NEC). Results: On the 6th day of life, concentrations of secretory immunoglobulin A, and lactoferrin in airway secretions and urine of the intervention group were significantly higher than those of the control group (p < 0.05). The intervention group showed younger corrected gestational age of no gastric retention during feeding, corrected gestational age of full enteral nutrition, the corrected gestational age of sucking began and per oral feeding than those in the control group (p < 0.05). The day of recovery to birth weight was earlier than those in the control group (p < 0.05). The rate of feeding intolerance and NEC incidence in the intervention group was significantly lower than in the control group (p < 0.05). Conclusions: Early oropharyngeal administration of colostrum improves immune function of the gastrointestinal tract and the systemic anti-infective capability in ELBWI on mechanical ventilation, promoting the maturity of gastrointestinal function, improving feeding condition, and reducing the risk of feeding intolerance and NEC.

Acetate supplementation produces antidepressant-like effect via enhanced histone acetylation.

BACKGROUND: Abnormal energy metabolism is often documented in the brain of patients and rodents with depression. In metabolic stress, acetate serves as an important source of acetyl coenzyme A (Ac-CoA). However, its exact role and underlying mechanism remain to be investigated. METHOD: We used chronic social failure stress (CSDS) to induce depression-like phenotype of C57BL/6J mice. The drugs were administered by gavage. We evaluated the depressive symptoms by sucrose preference test, social interaction, tail suspension test and forced swimming test. The dendritic branches and spine density were detected by Golgi staining, mRNA level was analyzed by real-time quantitative RT-PCR, protein expression level was detected by western blot, and the content of Ac-CoA was detected by ELISA kit. RESULT: The present study found that acetate supplementation significantly improved the depression-like behaviors of mice either in acute forced swimming test (FST) or in CSDS model and that acetate administration enhanced the dendritic branches and spine density of the CA1 pyramidal neurons. Moreover, the down-regulated levels of BDNF and TrkB were rescued in the acetate-treated mice. Of note, chronic acetate treatment obviously lowered the transcription level of HDAC2, HDAC5, HDAC7, HDAC8, increased the transcription level of HAT and P300, and boosted the content of Ac-CoA in the nucleus, which facilitated the acetylation levels of histone H3 and H4. LIMITATIONS: The effect of acetate supplementation on other brain regions is not further elucidated. CONCLUSION: These findings indicate that acetate supplementation can produce antidepressant-like effects by increasing histone acetylation and improving synaptic plasticity in hippocampus.

Estradiol-induced senescence of hypothalamic astrocytes contributes to aging-related reproductive function declines in female mice.

Hypothalamic astrocytes are important contributors that activate gonadotropin-releasing hormone (GnRH) neurons and promote GnRH/LH (luteinizing hormone) surge. However, the potential roles and mechanisms of astrocytes during the early reproductive decline remain obscure. The current study reported that, in intact middle-aged female mice, astrocytes within the hypothalamic RP3V accumulated senescence-related markers with increasing age. It employed an ovariectomized animal model and a cell model receiving estrogen intervention to confirm the estrogen-induced senescence of hypothalamic astrocytes. It found that estrogen metabolites may be an important factor for the estrogen-induced astrocyte senescence. In vitro molecular analysis revealed that ovarian estradiol activated PKA and up-regulated CYPs expression, metabolizing estradiol into 2-OHE2 and 4-OHE2. Of note, in middle-aged mice, the progesterone synthesis and the ability to promote GnRH release were significantly reduced. Besides, the expression of growth factors decreased and the mRNA levels of proinflammatory cytokines significantly increased in the aging astrocytes. The findings confirm that ovarian estradiol induces the senescence of hypothalamic astrocytes and that the senescent astrocytes compromise the regulation of progesterone synthesis and GnRH secretion, which may contribute to the aging-related declines in female reproductive function.

Quorum sensing inhibitors from marine bacteria Oceanobacillus sp. XC22919.

In this study, three active compounds isolated from Oceanobacillus sp. XC22919 were identified as 2-methyl-N-(2'-phenylethyl) butyramide (1), 3-methyl-N-(2'-phenylethyl)-butyramide (2) and benzyl benzoate (3), and were first reported to exhibit the apparent quorum sensing inhibitory activities against C. violaceum 026 and P. aeruginosa. Compounds 1-3 inhibited violacein production of C. violaceum 026 by 10.5-55.7, 11.2-55.7, and 27.2%-95.7%, respectively, and inhibited pyocyanin production of P. aeruginosa by 1.7-50.8, 39.1-90.7, and 57.2%-98.7%, respectively. The azocasein-degrading proteolytic rates of P. aeruginosa were observed by 13.4-31.5, 13.4-28.8, and 11.3%-21.1%, respectively. With respect to elastase, the range of inhibition of activity of compounds 1-3 was 2.1-30.3, 4.2-18.2, and 8.9%-15.7%, respectively. Compounds 1 and 3 also showed a concentration-dependent attenuation in biofilm formation, with the maximum of 50.6% inhibition, and 37.7% inhibition at 100 µg/mL, respectively.

Curcumin Ameliorates Memory Decline via Inhibiting BACE1 Expression and ß-Amyloid Pathology in 5×FAD Transgenic Mice.

Alzheimer's disease (AD) is the most common dementia and the trigger of its pathological cascade is widely believed to be the overproduction and accumulation of ß-amyloid protein (Aß) in the affected brain. However, effective AD remedies are still anxiously awaited. Recent evidence suggests that curcumin may be a potential agent for AD treatment. In this study, we used 5×FAD transgenic mice as an AD model to investigate the effects of curcumin on AD. Our results showed that curcumin administration (150 or 300 mg/kg/day, intragastrically, for 60 days) dramatically reduced Aß production by downregulating BACE1 expression, preventing synaptic degradation, and improving spatial learning and memory impairment of 5×FAD mice. These findings suggest that curcumin is a potential candidate for AD treatment.

[Postpartum pelvic floor rehabilitation on prevention of female pelvic floor dysfunction: a multicenter prospective randomized controlled study].

OBJECTIVE: To study the postpartum pelvic floor rehabilitation on the improvement of pelvic floor electrical physiological indexes and the prevention of female pelvic floor dysfunction in China. METHODS: A multicenter prospective randomized controlled study was carried out. From October 2011, postpartum women in five provinces were randomly assigned into treatment group and control group. The women in treatment group received electrical stimulation and biofeedback treatment. The women in control group performed pelvic floor muscle exercise at home. When 6 months and 12 months after delivery, comparing two groups of patients with pelvic floor electrical physiological indexes and pelvic organ prolapse quantitation measurements (POP-Q), to evaluate the effect of postpartum pelvic floor rehabilitation on the prevention of pelvic floor dysfunction. Pelvic floor impact questionnaire short form (PFIQ-7) and pelvic organ prolapse/incontinence sexual questionnaire-12 (PISQ-12) were used to evaluate the influence on quality of life and sexual life. RESULTS: Until June 2013, 324 women were participated, 124 in control group, 200 in treatment group. According to the baseline results, there was statistical significance in the results of pelvic floor electrical physiological indexes between the treatment and control groups in postpartum 6 months and 12 months; the proportion above level III of type I and type II muscle fibers strength in the treatment group, it was from 41.5% (83/200) and 40.5% (81/200) to 76.3% (145/190) and 79.5% (151/190) in postpartum 6 weeks and postpartum 6 months, increased to 80.6% (58/72) and 80.6% (58/72) in postpartum 12 months, improved significantly comparing with the control group (P < 0.01). According to Point Aa, treatment group and control group in the postpartum 6 weeks was (-2.2 ± 0.7) versus (-2.4 ± 0.6) cm, in postpartum 12 months (- 2.5 ± 1.1) versus (- 2.7 ± 0.6) cm, the improvement in treatment group was statistically significant (P < 0.01). And the other points were not significantly different (P > 0.05). There was no significant difference in the questionnaires in quality of life and quality of sexual life (P > 0.05). CONCLUSION: Neuromuscular electrical stimulation and biofeedback therapy in the early postpartum period could obviously improve pelvic floor electrical physiological indexes, and is beneficial to prevent the pelvic floor dysfunction.

Tripchlorolide improves cognitive deficits by reducing amyloid ß and upregulating synapse-related proteins in a transgenic model of Alzheimer's Disease.

Alzheimer's disease (AD) is characterized by early impairments in memory and progressive neurodegeneration. Disruption of synaptic plasticity processes that underlie learning and memory contribute partly to this pathophysiology. Tripchlorolide (T4 ), an extract from a traditional Chinese herbal Tripterygium wilfordii Hook F, has been shown to be neuroprotective in animal models of Parkinson's disease and to improve cognitive deficits in senescence-accelerated mouse P8. In this study, we investigated the effect of T4 on cognitive decline and synaptic plasticity in five times familial AD (5XFAD) mice co-expressing mutated amyloid precursor protein and presenilin-1. Five-month-old 5XFAD mice and wild type littermates were intraperitoneally injected with T4 , 5 µg/kg or 25 µg/kg, every other day for 60 days. T4 treatment significantly improved spatial learning and memory, alleviated synaptic ultrastructure degradation, up-regulated expression of synapse-related proteins, including synaptophysin, post-synaptic density-95, N-methyl-D-aspartate receptor subunit 1, phosphorylation of calcium/calmodulin dependent protein kinase II α, and phosphorylation of cyclic AMP-response element binding protein, and promoted activation of the phophoinositide-3-kinase-Akt-mammalian target of rapamycin signaling pathway in 5XFAD mice. Accumulation of amyloid ß (Aß) may contribute to synapse dysfunction and memory impairment in AD. We found that T4 treatment significantly reduced cerebral Aß deposits and lowered Aß levels in brain homogenates. These effects coincided with a reduction in cleavage of ß-carboxyl-terminal amyloid precursor protein (APP) fragment, levels of soluble APPß, and protein expression of ß-site APP cleaving enzyme 1. Taken together, our findings identify T4 as a potent negative regulator of brain Aß levels and show that it significantly ameliorates synaptic degeneration and cognitive deficits in a mouse model of AD.

Long-term ginsenoside Rg1 supplementation improves age-related cognitive decline by promoting synaptic plasticity associated protein expression in C57BL/6J mice.

In aging individuals, age-related cognitive decline is the most common cause of memory impairment. Among the remedies, ginsenoside Rg1, a major active component of ginseng, is often recommended for its antiaging effects. However, its role in improving cognitive decline during normal aging remains unknown and its molecular mechanism partially understood. This study employed a scheme of Rg1 supplementation for female C57BL/6J mice, which started at the age of 12 months and ended at 24 months, to investigate the effects of Rg1 supplementation on the cognitive performance. We found that Rg1 supplementation improved the performance of aged mice in behavior test and significantly upregulated the expression of synaptic plasticity-associated proteins in hippocampus, including synaptophysin, N-methyl-D-aspartate receptor subunit 1, postsynaptic density-95, and calcium/calmodulin-dependent protein kinase II alpha, via promoting mammalian target of rapamycin pathway activation. These data provide further support for Rg1 treatment of cognitive degeneration during aging.

[Profiles of reproduction-related mRNA expressions in hypothalamus of female mice with advancing age].

OBJECTIVE: To explore the effects of aging on the levels of reproduction-related mRNA genes including Gnrh, KISS1/KISS1r, estrogen receptor-alpha (ERα), estrogen receptor-beta (ERß) and progesterone receptor (PR) in hypothalamus. METHODS: Proestrus and metestrus in young (3-4 months) and middle-aged (10-11 months) female mice and diestrus in senile (18-19 months) female mice were observed. And the levels of related mRNA genes in preoptic area anterior hypothalamus (POA-AH) and medial basal hypothalamus (MBH) were determined by real-time polymerase chain reaction (RT-PCR). RESULTS: In middle-aged mice on proestrus, the level of Gnrh mRNA in POA-AH (0.896 ± 0.049) was significantly lower than that in young mice (1.228 ± 0.147, P = 0.049). The level of ERα mRNA in POA-AH decreased in young mice on proestrus whereas increased in middle-aged mice (0.432 ± 0.063 vs 0.603 ± 0.018, P = 0.016). The level of ERα mRNA of POA-AH, both in middle-aged mice (0.432 ± 0.063, P = 0.014) and senile mice (0.403 ± 0.145, P = 0.020) on diestrus, were significantly lower than that in young mice. The PR mRNA expression in middle-aged mice on proestrus (1.037 ± 0.037) was markedly lower than that in young mice (1.251 ± 0.081, P = 0.031) . In senile mice, the levels of Gnrh mRNA (1.520 ± 0.146, P = 0.004) and ERß mRNA (1.572 ± 0.184, P = 0.011) increased in POA-AH compared with that in young mice on metestrus. Aging had no effect upon KISS1 and KISS1r mRNA levels in POA-AH. In contrast, KISS1 mRNA level of MBH in middle-aged (1.663 ± 0.398, P = 0.037) and senile (2.622 ± 0.454, P = 0.014) mice obviously increased compared with the young mice group. CONCLUSION: Higher levels of ERα mRNA and decreases of PR and Gnrh mRNA in POA-AH in middle-aged mice on proestrus may play an important role in declining reproductive function.

Epigallocatechin-3-gallate suppresses 1-methyl-4-phenyl-pyridine-induced oxidative stress in PC12 cells via the SIRT1/PGC-1α signaling pathway.

BACKGROUND: Parkinson's disease is a high incidence neurodegenerative disease in elderly people, and oxidative stress plays an important role in the pathogenesis. Oxygen metabolism in the brain is high, which lacks an antioxidative protection mechanism. Recently, it has been found that polyphenols play an important role in antioxidation. (-)-epigallocatechin-3-gallate (EGCG) is an important component of tea polyphenols and its biological effects, such as strong antioxidation, scavenging of free radicals and anti-apoptosis, can pass through the blood brain barrier. The SIRT1/PGC-1α signaling pathway has not been reported in PC12 cells. Therefore, research of the protective mechanism of EGCG in PC12 cells damaged by -methyl-4-phenyl-pyridine (MMP+) may provide a new insight into protect against and treatment of Parkinson's disease. METHODS: MPP(+)-treated highly differentiated PC12 cells were used as the in vitro cell model. An MTT assay was used to investigate cell viability after EGCG treatment, a dichlorofluorescin diacetate assay was used to measure reactive oxygen species (ROS) production, western blot analysis was used to observe PGC-1α and SIRT1 protein expression, and real-time PCR to observe PGC-1α, SOD1 and GPX1 mRNA expression. RESULTS: PC12 cell viability was significantly reduced after MPP(+) treatment by 11.46% compared with that of the control (P < 0.05). However, cell viability was unchanged by 10 µmol/L EGCG treatment. In co-treatments with EGCG and MPP(+), cell viability was significantly increased by 12.92% (P < 0.05) and MPP(+)-induced ROS production was markedly decreased. PGC-1α mRNA expression was obviously upregulated by 21.51% (P < 0.05), and SOD1 and GPX1 mRNA expression was slightly increased by 12.94% and 15.63% (P > 0.05), respectively, by treatment with EGCG and then MPP(+) for 12 h. The mRNA expression of PGC-1α, SOD1 and GPX1 was increased by 25.17%, 40% and 146% (all P < 0.05), respectively, by treatment with EGCG and then MPP(+) for 24 h. Such effects were not observed with MPP(+) treatment alone. CONCLUSION: The SIRT1/PGC-1α pathway is one of the mechanisms of EGCG suppression of MPP(+)-induced injury of PC12 cells.

Ginsenoside Rb1 selectively inhibits the activity of L-type voltage-gated calcium channels in cultured rat hippocampal neurons.

AIM: To investigate the effect of ginsenoside Rb1 on voltage-gated calcium currents in cultured rat hippocampal neurons and the modulatory mechanism. METHODS: Cultured hippocampal neurons were prepared from Sprague Dawley rat embryos. Whole-cell configuration of the patch-clamp technique was used to record the voltage-gated calcium currents (VGCCs) from the hippocampal neurons,and the effect of Rb1 was examined. RESULTS: Rb1 (2-100 µmol/L) inhibited VGCCs in a concentration-dependent manner, and the current was mostly recovered upon wash-out. The specific L-type Ca(2+) channel inhibitor nifedipine (10 µmol/L) occluded Rb1-induced inhibition on VGCCs. Neither the selective N-type Ca(2+) channel blocker ω-conotoxin-GVIA (1 µmol/L), nor the selective P/Q-type Ca(2+) channel blocker ω-agatoxin IVA (30 nmol/L) diminished Rb1-sensitive VGCCs. Rb1 induced a leftward shift of the steady-state inactivation curve of I(Ca) to a negative potential without affecting its activation kinetics or reversal potential in the I-V curve. The inhibitory effect of Rb1 was neither abolished by the adenylyl cyclase activator forskolin (10 µmol/L), nor by the PKA inhibitor H-89 (10 µmol/L). CONCLUSION: Ginsenoside Rb1 selectively inhibits the activity of L-type voltage-gated calcium channels, without affecting the N-type or P/Q-type Ca(2+) channels in hippocampal neurons. cAMP-PKA signaling pathway is not involved in this effect.

Ginsenoside Rg1 attenuates ß-amyloid generation via suppressing PPARγ-regulated BACE1 activity in N2a-APP695 cells.

The level of ß-site APP-cleaving enzyme 1 (BACE1) has been documented to increase in the brains of patients with Alzheimer's disease, which has resulted in elevation of ß-amyloid (Aß) peptides. As a transcription factor binding site of the BACE1 promoter, peroxisome proliferator-activated receptor-γ (PPARγ) response element regulates the activity of the BACE1 promoter activity, indicating that PPARγ may become a potential target for Alzheimer's disease treatment. Recent studies have demonstrated that ginsenoside Rg1 which is an effective component of extracts of ginseng can prevent memory loss and improve cognitive function in a variety of animal models. However, the underlying mechanism remains unclear. In the present study, we found that Rg1 decreased the levels of Aß1₋40 and Aß1₋42 secreted in N2a-APP695 cells. The expression levels of both BACE1 mRNA and protein as well as ß-CTFs, a cleavaged C-terminal fragment of APP by BACE1, were reduced in cells treated with Rg1. Moreover, Rg1 treatment led to a translocation of PPARγ from cytoplasm to nuclear. Intriguingly, Rg1, like pioglitazone (a PPARγ agonist), suppressed BACE1 activity in N2a-APP695 cells, while its effect on BACE1 activity was attenuated by GW9662 (a PPARγ antagonist). These results indicate that Rg1 may be a PPARγ agonist to enhance the binding of nuclear PPARγ to the BACE1 promoter, which may in turn inhibit the transcription and translation of BACE1, suppress the activity of BACE1, and ultimately attenuate Aß generation. Therefore, ginsenoside Rg1 may serve as a promising agent in modulating Aß-related pathology in Alzheimer's disease.