Astragaloside IV against Alzheimer's disease via microglia-mediated neuroinflammation using network pharmacology and experimental validation.

Alzheimer's disease (AD) is one of the most prevalent neurodegenerative diseases in the world. The effective therapeutic methods and drugs are still not clear. Astragaloside IV (AS-IV), a triterpenoid saponin isolated from the root of Huangqi, has a beneficial effect in the treatment of AD. However, whether AS-IV alters microglia in the inflammation of AD is still ambiguous. In our study, 99 common targets were collected between AS-IV and AD. BCL2 apoptosis regulator (Bcl-2), pro-apoptotic BCL-2 protein BAX, epidermal growth factor receptor (EGFR), and receptor tyrosine phosphatase type C (PTPRC) were screened for inflammation and microglia in the above targets by network pharmacology. Interleukin-1ß (IL-1ß) and EGFR both interact with signal transducer and activator of transcription 3 (STAT3) by a protein interaction network, and IL-1ß had a higher affinity for AS-IV based on molecular docking. Enrichment revealed targets involved in the regulation of neuronal cell bodies, growth factor receptor binding, EGFR tyrosine kinase inhibitor resistance., etc. Besides, AS-IV alleviated the reduced cell proliferation in amyloid-beta (Aß)-treated microglial BV2 cells. AS-IV affected BV2 cell morphological changes and decreased cluster of differentiation 11b (CD11b) gene, IL-1ß, and EGFR mRNA levels increment during lipopolysaccharide (LPS) injury in BV2 cell activation. Therefore, AS-IV may regulate microglial activation and inflammation via EGFR-dependent pathways in AD. EGFR and IL-1ß are vital targets that may relate to each other to coregulate downstream molecular functions in the cure of AD. Our study provides a candidate drug and disease target for the treatment of neurodegenerative diseases in the clinic.

Ardisia gigantifolia stapf (Primulaceae): A review of ethnobotany, phytochemistry, pharmacology, clinical application, and toxicity.

ETHNOPHARMACOLOGICAL RELEVANCE: Ardisia gigantifolia Stapf, known as Zou-ma-tai (in Chinese), is a traditional folk medicine, which was commonly used by Dong, Jing, Li, Maonan, Miao, Mulam, Yao, and Zhuang people. The main use of A. gigantifolia is the treatment of rheumatoid arthritis, gouty arthritis, fractures, osteoproliferation, traumatic injuries, gynecological, and neurological diseases. Current studies have shown that the plant has various bioactive components, especially gigantifolinol, which has anti-tumor, anti-inflammatory, anti-tuberculosis, and neuroprotective activities. However, to date, few reviews have been made to summarize A. gigantifolia's related studies. AIMS OF THE REVIEW: This review aimed to summarize the traditional use, phytochemistry, pharmacology, clinical applications, and toxicity of A. gigantifolia, which expect to provide theoretical support for future utilization and highlight the further investigation of this vital plant. MATERIALS AND METHODS: The information related to A. gigantifolia were collated by surveying the traditional medicine books, ethnomedicinal publications, and searching academic resource databases including Web of Science, SciFinder, Springer Link, Pub Med, Science Direct, CNKI, and CQVIP database. RESULTS: A. gigantifolia has been used as a traditional folk medicine for more than 400 years in China. Different parts of the plant, including the aerial part, root, rhizome, and leaf, are mainly used as herbal medicine to treat rheumatoid arthritis, traumatic injuries, gynecological, etc. Currently, 165 compounds have been identified from the plant, including triterpenes, phenolics, coumarins, quinones, volatile oil, and sterols, 137 of which were identified from the rhizome parts. Pharmacological research showed that A. gigantifolia has various bioactivities, such as anti-tumor, anti-inflammatory, anti-oxidant, anti-thrombus, anti-tuberculosis, cough expectorant, and neuroprotective activities. Clinical studies have shown that the plant has no toxic side effects. In vivo administration at the maximum dose was not lethal, indicating the plant's safety. CONCLUSION: To date, most bioactive compounds are identified from the rhizomes of A. gigantifolia, which pharmacological activity and clinical observational studies have validated the plant's traditional use as a treatment for rheumatoid arthritis. It would be helpful to verify the mechanism of some components in vivo, such as gigantifolinol. Moreover, the plant's triterpenoid saponins demonstrated valid anti-tumor effects, especially the AG4 and AG36 compounds, which were shown to have anti-breast cancer effects both in vitro and in vivo. Further research on these components, including molecular mechanisms and in vivo metabolic regulation, needs to be confirmed.

Exosomal MicroRNA-126 from RIPC Serum Is Involved in Hypoxia Tolerance in SH-SY5Y Cells by Downregulating DNMT3B.

Ischemic tolerance in the brain can be induced by transient limb ischemia, and this phenomenon is termed remote ischemic preconditioning (RIPC). It still remains elusive how this transfer of tolerance occurs. Exosomes can cross the blood-brain barrier, and some molecules may transfer neuroprotective signals from the periphery to the brain. Serum miRNA-126 is associated with ischemic stroke, and exosomal miRNA-126 has shown protective effects against acute myocardial infarction. Therefore, this study aims to explore whether exosomal miRNA-126 from RIPC serum can play a similar neuroprotective role. Exosomes were isolated from the venous serum of four healthy young male subjects, both before and after RIPC. Exosomal miRNA-126 was measured by real-time PCR. The miRNA-126 target sequence was predicted by bioinformatics software. SH-SY5Y neuronal cells were incubated with exosomes, and the cell cycle was analyzed by flow cytometry. The expression and activity of DNA methyltransferase (DNMT) 3B, a potential target gene of miRNA-126, were examined in SH-SY5Y cells. The cell viability of SH-SY5Y cells exposed to oxygen-glucose deprivation (OGD) was also investigated. To confirm the association between miRNA-126 and DNMT3B, we overexpressed miRNA-126 in SH-SY5Y cells using lentiviral transfection. miRNA-126 expression was upregulated in RIPC exosomes, and bioinformatics prediction showed that miRNA-126 could bind with DNMT3B. DNMT levels and DNMT3B activity were downregulated in SH-SY5Y cells incubated with RIPC exosomes. After overexpression of miRNA-126 in SH-SY5Y cells, global methylation levels and DNMT3B gene expression were downregulated in these cells, consistent with the bioinformatics predictions. RIPC exosomes can affect the cell cycle and increase OGD tolerance in SH-SY5Y cells. RIPC seems to have neuroprotective effects by downregulating the expression of DNMTs in neural cells through the upregulation of serum exosomal miRNA-126.

Effects of 5-Aza on p-Y1472 NR2B related to learning and memory in the mouse hippocampus.

BACKGROUND: We have previously reported that 5-Aza-2-deoxycytidine (5-Aza-cdR) can repress protein serine/threonine phosphatase-1γ (PP1γ) expression and activity in the mouse hippocampus and affect the behaviour of mice in a water maze. It is well known that the phosphorylation of N-methyl-d-aspartate receptor 2B subunit (NR2B) plays a role in behaviour. In this study, we examined whether 5-Aza-cdR affects NR2B phosphorylation at tyrosine 1472 (p-Y1472 NR2B) and whether it affected the responses of the mice in a passive avoidance test. METHODS: 5-Aza-cdR (10 µM) was administered to mice via intracerebroventricular injection (i.c.v). The learning and memory behaviour of the mice were evaluated by measuring their response in a step-down type passive avoidance test 24 h after the injection. The mRNA level of NR2B was measured by real-time PCR. NR2B and p-Y1472 NR2B protein expression in the mouse hippocampus was detected by western blot and immunofluorescence. CDK5 activity was detected by the ADP-Glo™ + CDK5/p35 Kinase Enzyme System. To further clarify whether the 5-Aza-cdR effects on behaviour were dependent on cellular proliferation or not, the effect of 5-Aza-cdR on the expression level of NR2B, the phosphorylation level of p-Y1472 NR2B, cell viability and the cell cycle were analysed using the immortalized mouse hippocampal neuronal cells neural cell line HT22 treated with 10 µM 5-Aza-cdR compared with an untreated control group. RESULTS: After injection with 5-Aza-cdR, the behaviour of the mice in the step-down test was improved, while their phosphorylation level of p-Y1472 NR2B was increased and their CDK5 activity was decreased in the hippocampus. In vitro experiments showed 10 µM 5-Aza-cdR increased the p-Y1472 NR2B phosphorylation level with inhibition of cell viability and cell cycle arrest. CONCLUSIONS: Our results suggested that the effect of 5-Aza-cdR on behaviour may be related to the increase in phosphorylation of p-Y1472 NR2B in the hippocampus.

Cloning and characterization of a Ca(2+)/H(+) exchanger from the halophyte Salicornia europaea L.

The calcium ion (Ca(2+)), which functions as a second messenger, plays an important role in plants' responses to various abiotic stresses, and Ca(2+)/H(+) exchangers (CAXs) are an important part of this process. In this study, we isolated and characterized a putative Ca(2+)/H(+) exchanger gene (SeCAX3) from Salicornia europaea L., a succulent, leafless euhalophyte. The SeCAX3 open reading frame was 1368 bp long and encoded a 455-amino-acid polypeptide that showed 67.9% similarity to AtCAX3. SeCAX3 was expressed in the shoots and roots of S. europaea. Expression of SeCAX3 was up-regulated by Ca(2+), Na(+), sorbitol, Li(+), abscisic acid, and cold treatments in shoots, but down-regulated by Ca(2+), sorbitol, abscisic acid, and cold treatments in roots. When SeCAX3 was transformed into a Ca-sensitive yeast strain, the transformed cells were able to grow in the presence of 200 mM Ca(2+). Furthermore, SeCAX3 conferred drought, salt, and cold tolerance in yeast. Compared with the control strains, the yeast transformants expressing SeCAX3 were able to grow well in the presence of 30 mM Li(+), 150 mM Mg(2+), or 6 mM Ba(2+). These results showed that the expression of SeCAX3 in yeast suppressed its Ca(2+) hypersensitivity and conferred tolerance to Mg(2+) and Ba(2+). Together, these findings suggest that SeCAX3 might be a Ca(2+) transporter that plays a role in regulating cation tolerance and the responses of S. europaea to various abiotic stresses.