Acupuncture therapy for Alzheimer's disease: The effectiveness and potential mechanisms.

Alzheimer's disease (AD) is a common neurodegenerative disease that accounts for approximately 70% of dementia. Following the global escalation of the aging process, the morbidity of AD is increasing rapidly. The current treatment for AD is mainly limited to medications, such as acetylcholinesterase inhibitors. However, the efficacy of acetylcholinesterase inhibitors in improving memory and cognitive functions is not satisfactory. It is a challenge to find an effective alternative therapy for ameliorating AD symptoms. As an important therapeutic technique in traditional Chinese medicine, acupuncture has been proved effective in treating many neurologic diseases including AD. The efficacy of acupuncture is also acknowledged by the National Institutes of Health of the United States. Here, we summarized the effectiveness of acupuncture for treating AD. Especially, the role of acupuncture at certain acupuncture points in modulating the brain function through meridians activity based on Chinese meridian theory is discussed. How acupuncture at a certain acupoint can improve AD symptoms is also described. Furthermore, the possible molecular mechanisms of acupuncture for AD are reviewed, and the role of acupuncture in modulating signaling molecules in neural protection and homeostasis is highlighted. This study may help to understand the theoretical basis and potential molecular mechanisms of acupuncture therapy for AD.

MUD1, a RING-v E3 ubiquitin ligase, has an important role in the regulation of pectin methylesterification in Arabidopsis seed coat mucilage.

Pectin is one of the major components of plant primary cell wall polysaccharides. The degree of pectin methylesterification (DM) plays an important role in the process of plant growth. However, little is known about the underlying regulatory mechanisms during the process of pectin demethylesterification. Here, we characterized mucilage defect 1 (mud1), a novel Arabidopsis thaliana mutant, which displays increased mucilage adherence resulting from increased activities of pectin methylesterases (PMEs) and decreased degree of pectin methylesterification (DM). MUD1 encodes a nuclear protein with a Really Interesting New Gene (RING)-v domain and is highly expressed in developing seed coat when seed coat mucilage starts to accumulate. We have demonstrated that MUD1 has E3 ubiquitin ligase activity in vitro. The expression of PME-related genes, including MYB52, LUH, SBT1.7, PMEI6, and PMEI14 decreased considerably in mud1. We propose that MUD1 acts as an ubiquitin ligase potentially regulating the DM of pectin by post-transcriptionally removing proteins that normally negatively regulate the level or activity of PMEs in the seed coat mucilage.

Potato NAC Transcription Factor StNAC053 Enhances Salt and Drought Tolerance in Transgenic Arabidopsis.

The NAC (NAM, ATAF1/2, and CUC2) transcription factors comprise one of the largest transcription factor families in plants and play important roles in stress responses. However, little is known about the functions of potato NAC family members. Here we report the cloning of a potato NAC transcription factor gene StNAC053, which was significantly upregulated after salt, drought, and abscisic acid treatments. Furthermore, the StNAC053-GFP fusion protein was found to be located in the nucleus and had a C-terminal transactivation domain, implying that StNAC053 may function as a transcriptional activator in potato. Notably, Arabidopsis plants overexpressing StNAC053 displayed lower seed germination rates compared to wild-type under exogenous ABA treatment. In addition, the StNAC053 overexpression Arabidopsis lines displayed significantly increased tolerance to salt and drought stress treatments. Moreover, the StNAC053-OE lines were found to have higher activities of superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) under multiple stress treatments. Interestingly, the expression levels of several stress-related genes including COR15A,DREB1A, ERD11, RAB18, ERF5, and KAT2, were significantly upregulated in these StNAC053-overexpressing lines. Taken together, overexpression of the stress-inducible StNAC053 gene could enhance the tolerances to both salt and drought stress treatments in Arabidopsis, likely by upregulating stress-related genes.

Astragalus protects PC12 cells from 6-hydroxydopamine-induced neuronal damage: A serum pharmacological study.

Accumulating evidence has already indicated that traditional Chinese medicine (TCM) possesses tremendous potential for treating neurodegenerative diseases. Astragalus, also named Huangqi, is a famous traditional medical herb that can be applied to treat cerebral ischemia and prevent neuronal degeneration. Nevertheless, the underlying mechanisms remain largely unexplored. In the present study, Astragalus-containing serum (ASMES) was prepared and added into the culture medium of PC12 cells to explore its neuroprotective effect on 6-hydroxydopamine (6-OHDA)-caused neuronal toxicity. Our data showed that ASMES significantly ameliorated the cellular viability of cultured PC12 cells against the neurotoxicity induced by 6-OHDA (P < 0.05). Moreover, ASMES significantly decreased the cell apoptosis triggered by 6-OHDA (P < 0.01). Furthermore, 2',7'-dichlorofluorescin diacetate assay was performed to detect the changes in oxidative stress, and we showed that 6-OHDA elevated the production of reactive oxygen species (ROS), whereas ASMES significantly reversed these changes (P < 0.01). Besides, mitochondrial membrane potential (MMP) assay showed that ASMES could restore 6-OHDA-damaged MMP in cultured PC12 cells (P < 0.05). In conclusion, Astragalus could protect PC12 cells from 6-OHDA-caused neuronal toxicity, and possibly, the ROS-mediated apoptotic pathway participated in this process. Collectively, our findings provided valuable insights into the potential in treatment of neurodegenerative diseases.

Melatonin regulates Aß production/clearance balance and Aß neurotoxicity: A potential therapeutic molecule for Alzheimer's disease.

Alzheimer's disease (AD) is an age-related neurodegenerative disease with multiple predisposing factors and complicated pathogenesis. Aß peptide is one of the most important pathogenic factors in the etiology of AD. Accumulating evidence indicates that the imbalance of Aß production and Aß clearance in the brain of AD patients leads to Aß deposition and neurotoxic Aß oligomer formation. Melatonin shows a potent neuroprotective effect and can prevent or slow down the progression of AD, supporting the view that melatonin is a potential therapeutic molecule for AD. Melatonin modulates the regulatory network of secretase expression and affects the function of secretase, thereby inhibiting amyloidogenic APP processing and Aß production. Additionally, melatonin ameliorates Aß-induced neurotoxicity and probably promotes Aß clearance through glymphatic-lymphatic drainage, BBB transportation and degradation pathways. In this review, we summarize and discuss the role of melatonin against Aß-dependent AD pathogenesis. We explore the potential cellular and molecular mechanisms of melatonin on Aß production and assembly, Aß clearance, Aß neurotoxicity and circadian cycle disruption. We summarize multiple clinical trials of melatonin treatment in AD patients, showing that melatonin has a promising effect on improving sleep quality and cognitive function. This review aims to stimulate further research on melatonin as a potential therapeutic agent for AD.

Buyang Huanwu Decoction Vigorously Rescues PC12 Cells Against 6-OHDA-Induced Neurotoxicity via Akt/GSK3ß Pathway Based on Serum Pharmacology Methodology.

Buyang Huanwu decoction (BYHWD), as a popular traditional Chinese medicine formula, was widely used for treating ischemic diseases. However, in the area of neurodegenerative diseases, the researches focused on BYHWD are rare but promising, and molecular mechanisms underlying are largely elusive. 6-Hydroxydopamine (6-OHDA), a dopaminergic-specific neurotoxin, is extensively used to establish neurotoxic model in vivo and in vitro. In our present study, we prepared drug-containing serum of BYHWD (Buyang Huanwu drug-containing serum [BYHWS]) based on serum pharmacology methodology. Neurotoxic model in vitro was established in PC12 cells, and innovative experimental grouping method was adopted to investigate neuroprotective effects of BYHWS on neurotoxicity induced by 6-OHDA exposure. Remarkably, BYHWS vigorously rescued PC12 cells from 6-OHDA-induced neurotoxicity even to surpass 100% in cell viability. Moreover, Hoechst/propidium iodide (PI) staining revealed that cell apoptotic rate was reduced significantly after incubation of BYHWS. Besides, BYHWS effectively restored the disruption of mitochondrial membrane potential and attenuated the elevation of intracellular reactive oxygen species level caused by 6-OHDA insult. Furthermore, BYHWS remarkably reversed the dephosphorylation of Akt (protein kinase B) and glycogen synthase kinase-3ß (GSK3ß) evoked by 6-OHDA. The above protective effects were attenuated by coculturing with Akt inhibitor LY294002. In summary, we concluded that the BYHWS vigorously blocked 6-OHDA-induced neurotoxicity via Akt/GSK3ß pathway and provided a novel insight into roles of BYHWD in the clinical practices on neurodegenerative diseases.

Resveratrol Protects PC12 Cell against 6-OHDA Damage via CXCR4 Signaling Pathway.

Resveratrol, herbal nonflavonoid polyphenolic compound naturally derived from grapes, has long been acknowledged to possess extensive biological and pharmacological properties including antioxidant and anti-inflammatory ones and may exert a neuroprotective effect on neuronal damage in neurodegenerative diseases. However, the underlying molecular mechanisms remain undefined. In the present study, we intended to investigate the neuroprotective effects of resveratrol against 6-OHDA-induced neurotoxicity of PC12 cells and further explore the possible mechanisms involved. For this purpose, PC12 cells were exposed to 6-OHDA in the presence of resveratrol (0, 12.5, 25, and 50 µM). The results showed that resveratrol increased cell viability, alleviated the MMP reduction, and reduced the number of apoptotic cells as measured by MTT assay, JC-1 staining, and Hoechst/PI double staining (all p < 0.01). Immunofluorescent staining and Western blotting revealed that resveratrol averts 6-OHDA induced CXCR4 upregulation (p < 0.01). Our results demonstrated that resveratrol could effectively protect PC12 cells from 6-OHDA-induced oxidative stress and apoptosis via CXCR4 signaling pathway.

Neuroprotection of resveratrol against neurotoxicity induced by methamphetamine in mouse mesencephalic dopaminergic neurons.

Resveratrol is originally extracted from huzhang, a Chinese herbal medicine. Recently, resveratrol has attracted a great of attention due to its antioxidant and antiapoptotic properties. Although the neuroprotection of resveratrol on neural damages in various models has been well characterized, little is known about the role of resveratrol in methamphetamine (MA) induced neurotoxicity in mesencephalic dopaminergic neurons. Dopaminergic neurons were isolated from midbrain of mouse embryos at embryonic day 15 and cultured in the presence of MA and resveratrol. Cell viability was examined by MTT assay and the apoptosis was assessed using Hoechst33342/PI double staining. To evaluate the Oxidative damage, ROS assay was performed. Moreover, the changes of time course of intracellular free calcium concentration ([Ca(2+) ]i) were analyzed with Fluo-3/AM tracing. The data showed that MA induced the neurotoxicity of cultured cells in a dose-dependent manner. Resveratrol significantly increased cellular viability and retarded cell apoptosis. Furthermore, resveratrol also attenuated MA induced ROS production and intracellular free calcium overload. Our results suggest that resveratrol protects dopaminergic neurons from MA-induced neuronal cytotoxicity, which, at least partly, is mediated by inhibition of [Ca(2+) ]i and oxidative stress. © 2015 BioFactors 41(4):252-260, 2015.

Neuroprotective effects of resveratrol on damages of mouse cortical neurons induced by ß-amyloid through activation of SIRT1/Akt1 pathway.

Resveratrol (3,5,4'-tihydroxy-trans-stilbene), a polyphenolic phytoalexin found in the skin and seeds of grapes, has been reported to possess a wide range of biological and pharmacological activities including antioxidant, anti-inflammatory, and antimutagenic effects. The present study intended to explore the neuroprotective effects of resveratrol against Aß25-35 -induced neurotoxicity of cultured mouse cortical neurons and the possible mechanisms involved. For this purpose, mouse cortical neurons were cultured and exposed to 30 µM Aß25-35 in the absence or presence of resveratrol (5, 10, and 25 µM). In addition, the potential contribution of the SIRT1/Akt1 neuroprotective pathway in resveratrol-mediated protection against Aß25-35 -induced neurotoxicity was also investigated. The results showed that resveratrol dose-dependently increased cell viability and reduced the number of apoptotic cells as measured by 3-[4,5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide (MTT) assay, lactate dehydrogenase (LDH) activity assay, reactive oxygen species (ROS) activity assay, and Hoechst/PI double staining. Further study revealed that resveratrol through activation of SIRT1/Akt1 to avert apoptosis. These findings raise the possibility that resveratrol may be a potent therapeutic compound against the neurodegenerative diseases.

Hyperthermia induces upregulation of connexin43 in the golden hamster neural tube.

BACKGROUND: During early embryonic development, maternal exposure to hyperthermia induces neural tube defects (NTDs). Connexins are essential for the formation of gap junctions and Connexin43 (Cx43) is crucially involved in neural tube development. This study was designed to explore the potential role of Cx43 in NTDs induced by hyperthermia. METHODS: Using PCR, the Cx43 cDNA was screened from the cDNA library of the neural tube from golden hamsters treated with hyperthermia. By Northern blot, the expression of Cx43 in heat-treated and control groups of the golden hamsters at day 8.5 after mating was detected. Finally, by in situ hybridization and RT-PCR, the expression of Cx43 was examined in the neural tube at different time points after heat treatment. RESULTS: Cx43 was stably expressed in heat-treated and control groups of the golden hamsters, whereas the expression was evidently higher in the heat-treated group. Cx43 expression in the neural tube at different time points after heat treatment was significantly higher than in control groups (p < 0.01). Hyperthermia did not induce any mutations in Cx43 cDNA. CONCLUSIONS: Our data provide the first evidence that hyperthermia induces upregulation of Cx43 in the golden hamster neural tube. NTDs caused by hyperthermia may be intimately related with the overexpression of Cx43.

Neuroprotective effects of Buyang Huanwu decoction against hydrogen peroxide induced oxidative injury in Schwann cells.

ETHNOPHARMACOLOGICAL RELEVANCE: Buyang Huanwu decoction (BYHWD) is a traditional Chinese medicine and can be used to promote peripheral nerve regeneration. However the regenerative mechanism of BYHWD remains unclear. The objective of this study was to investigate the protective mechanisms of BYHWD in Schwann cells damaged by hydrogen peroxide (H(2)O(2)). MATERIALS AND METHODS: Schwann cells which were derived from neonatal sciatic nerves of rats were used in subsequent experiments. Schwann cells were injured by various concentrations of H(2)O(2) (0.25, 0.5 and 1mM final concentration). BYHWD (600 µg/ml final concentration) was added to the medium either simultaneously or 1h later after the addition of H(2)O(2). Subsequently, methyl thiazolyl tetrazolium (MTT) assay was performed. Superoxide dismutase (SOD) activity and malondialdehyde (MDA) levels were also examined after 12h. The expression of Caspase 3 and the concentration of intercellular Ca(2+) ([Ca(2+)]i) were also determined. RESULTS: Among three concentrations of H(2)O(2), 0.5mM H(2)O(2) induced Schwann cells swelled and neuritis disappeared after 12h. In the presence of BYHWD, MTT assay showed that more cells were viable in comparison with the H(2)O(2) injury group. Moreover, the addition of BYHWD has also increased the SOD activity with decreased in MDA level. Furthermore, the concentration of [Ca(2+)]i and expression of Caspase 3 were decreased with the addition of BYHWD in culture. CONCLUSIONS: Our results revealed that BYHWD protected Schwann cells from oxidative injury. The mechanism of BYHWD promoting neural regeneration possibly associated with its anti-oxidative activity.

Effects of Buyang Huanwu Decoction on neurite outgrowth and differentiation of neuroepithelial stem cells.

To determine the effects of Buyang Huanwu Decoction (BYHWD), a traditional Chinese medicine, on neurite outgrowth and differentiation of neuroepithelial stem cells (NEPs), NEPs were isolated from embryonic neural tube and cultured in medium with rat serum containing BYHWD, which was prepared from rats administrated orally with BYHWD. The average neurite length of NEPs grew significantly longer in rat serum containing BYHWD than in control serum without BYHWD. More neurofilament (NF) positive cells and glial fibrillary acidic protein (GFAP) positive cells were detected in NEPs cultured in the presence of BYHWD. Besides, when cultured NEPs were loaded with Fluo-3-AM, the fluorescence intensity obtained from NEPs cultured in serum with BYHWD was significantly lower than that from NEPs cultured in control serum without BYHWD. Our results indicate that BYHWD could exert a promotion effect on neurite outgrowth and differentiation of NEPs.

Buyang Huanwu Decoction promotes growth and differentiation of neural progenitor cells: using a serum pharmacological method.

Buyang Huanwu Decoction (BYHWD), a traditional Chinese medicine, has been developed as a drug to be used for treatment of stroke for hundreds of years. However, the underlying mechanisms remain unknown. In this study, a serum pharmacological method was employed to investigate the effects of BYHWD on growth and differentiation of cultured neural progenitor cells derived from embryonic hippocampus. In culture medium containing BYHWD, the average neurite length of neural progenitor cells grew significantly longer than in control serum without BYHWD. Moreover, more neurofilament (NF) positive cells and glial fibrillary acidic protein (GFAP) positive cells were detected in the presence of BYHWD. The concentration of intracellular Ca(2+) in progenitor cells cultured with BYHWD was significantly lower than that cultured without BYHWD. These results suggest that BYHWD may promote growth and differentiation of neural progenitor cells.