A Novel Paradigm Defines Functional Molecule Clusters for an Anti-Alzheimer's Disease Recipe from Traditional Chinese Medicine.

Traditional Chinese Medicine (TCM) prescriptions are organically composed of compatible herbs according to the TCM theory. The complex ingredients of TCM could act on multiple targets through various pathways simultaneously to exert pharmacological effects, making TCM an unrivaled gem in the medical world. However, due to a lack of comprehensive and standard study methods, the research of TCM products has been quite limited. A novel paradigm that could aid in the discovery of the material basis and fully clarify the mechanism of TCM prescriptions is urgently needed. In this study, a similarity analysis based on molecular fingerprints was adopted to explore the representative molecules of the Tiaoxin recipe, a Chinese patent formula approved by the National Medical Products Administration (NMPA) for the treatment of mild-to-moderate Alzheimer's disease (AD), and 38 out of 1047 chemicals were finally screened out. Next, we tried to define a new concept of a "functional molecule cluster" for chemicals with similar pharmacological effects to elucidate how the chemical mixture from TCMs produce their therapeutic effects. Four anti-AD functional molecule clusters from the Tiaoxin recipe were identified: an anti-inflammatory cluster, an anti-ROS cluster, an anti-AChE activity cluster, and an anti-A[Formula: see text] aggregation cluster. Furthermore, the chemicals from the anti-inflammatory cluster and anti-ROS cluster were proved to display their multi-target and multi-pathway roles partially or mainly through molecules of the TLR4-MYD88-NF-[Formula: see text]B and Keap1-Nrf2-ARE pathways. The functional molecule clusters may be vital to the explanation of the efficacy of the Tiaoxin recipe, which could give us a more profound understanding of TCM prescriptions. Our paradigm may open a novel path for TCM research.

Smilagenin induces expression and epigenetic remodeling of BDNF in alzheimer's disease.

BACKGROUND: Smilagenin (SMI) is a lipid-soluble steroidal sapogenin, extracted from traditional Chinses medicinal herbs Radix Asparagi, which is extracted from the dry root of Asparagus cochinchinensis (Lour.) Merr. We previously found that SMI significantly increased brain-derived neurotrophic factor (BDNF) expression in Aß-intoxicated SH-SY5Y cells. METHODS: In this study, we performed behavioral tests to analyze cognitive function of WT and APP/PS1 mice treated with or without SMI, and found that SMI could significantly improve the learning and memory ability of APP/PS1 mice. Moreover, immunofluorescence and ELISA results showed that SMI pretreatment could effectively reduce the deposition of ß-amyloid plaques in the cortex and hippocampus of APP/PS1 mice (26 mg/kg/day for 60 days) and inhibit the secretion of Aß1-42 in N2a/APPswe cells (10 µM concentration for 24 hours). RESULTS: Mechanistically, SMI enhanced BDNF mRNA expression, elevated the global level of H3AC and H4AC, and increased the expression of P300 in AD models. Furthermore, chromatin immunoprecipitation results showed that SMI could increase the levels of H3AC and H4AC at the promoter of BDNF promoter Ⅱ and Ⅳ, indicating that SMI epigenetically regulates BDNF expression through HAT enhancement. To further verify the critical role of P300 by which SMI upregulated histone acetylation in BDNF, AD mice were treated with SMI and C646 simultaneously. Behavioral experiments showed that the improvement effects of SMI on cognitive impairment were abolished after P300 inhibition in APP/PS1 mice. CONCLUSIONS: Our research for the first time demonstrated that SMI showed neuroprotective effects by increasing the expression of P300 protein, thus upregulating histone acetylation levels in the promoter region of BDNF and promoting its transcription. Our findings provide an important theoretical basis for the treatment of Alzheimer's disease with SMI extracted from Asparagus cochinchinensis (Lour.) Merr.

CircEPS15, as a sponge of MIR24-3p ameliorates neuronal damage in Parkinson disease through boosting PINK1-PRKN-mediated mitophagy.

Despite growing evidence that has declared the importance of circRNAs in neurodegenerative diseases, the clinical significance of circRNAs in dopaminergic (DA) neuronal degeneration in the pathogenesis of Parkinson disease (PD) remains unclear. Here, we performed rRNA-depleted RNA sequencing and detected more than 10,000 circRNAs in the plasma samples of PD patients. In consideration of ROC and the correlation between Hohen-Yahr stage (H-Y stage) and Unified Parkinson Disease Rating Scale-motor score (UPDRS) of 40 PD patients, circEPS15 was selected for further research. Low expression of circEPS15 was found in PD patients and there was a negative positive correlation between the circEPS15 level and severity of PD motor symptoms, while overexpression of circEPS15 protected DA neurons against neurotoxin-induced PD-like neurodegeneration in vitro and in vivo. Mechanistically, circEPS15 acted as a MIR24-3p sponge to promote the stable expression of target gene PINK1, thus enhancing PINK1-PRKN-dependent mitophagy to eliminate damaged mitochondria and maintain mitochondrial homeostasis. Thus, circEPS15 rescued DA neuronal degeneration through the MIR24-3p-PINK1 axis-mediated improvement of mitochondrial function. This study reveals that circEPS15 exerts a critical role in participating in PD pathogenesis, and may give us an insight into the novel avenue to develop potential biomarkers and therapeutic targets for PD.Abbreviations: AAV: adeno-associated virus; DA: dopaminergic; FISH: fluorescence in situ hybridizations; HPLC: high-performance liquid chromatography; H-Y stage: Hohen-Yahr stage; LDH: lactate dehydrogenase; MMP: mitochondrial membrane potential; MPTP/p: 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine/probenecid; NC: negative control; PD: Parkinson disease; PINK1: PTEN induced kinase 1; PBS: phosphate-buffered saline; ROS: reactive oxygen species; SNpc: substantia nigra pars compacta; TEM: transmission electron microscopy; UPDRS: Unified Parkinson's Disease Rating Scale-motor score.

Immunotherapy for Alzheimer's disease: targeting ß-amyloid and beyond.

Alzheimer's disease (AD) is the most common neurodegenerative disease in the elderly worldwide. However, the complexity of AD pathogenesis leads to discrepancies in the understanding of this disease, and may be the main reason for the failure of AD drug development. Fortunately, many ongoing preclinical and clinical studies will continually open up avenues to unravel disease mechanisms and guide strategies for AD diagnosis and drug development. For example, immunotherapeutic strategies targeting amyloid-ß (Aß) and tau proteins were once deemed almost certainly effective in clinical treatment due to the excellent preclinical results. However, the repeated failures of clinical trials on vaccines and humanized anti-Aß and anti-tau monoclonal antibodies have resulted in doubts on this strategy. Recently, a new anti-Aß monoclonal antibody (Aducanumab) has been approved by the US Food and Drug Administration, which brings us back to the realization that immunotherapy strategies targeting Aß may be still promising. Meanwhile, immunotherapies based on other targets such as tau, microglia and gut-brain axis are also under development. Further research is still needed to clarify the forms and epitopes of targeted proteins to improve the accuracy and effectiveness of immunotherapeutic drugs. In this review, we focus on the immunotherapies based on Aß, tau and microglia and their mechanisms of action in AD. In addition, we present up-to-date advances and future perspectives on immunotherapeutic strategies for AD.

Circular RNA Cwc27 contributes to Alzheimer's disease pathogenesis by repressing Pur-α activity.

Circular RNAs (circRNAs) have gained growing attention in participating in various biological processes and referring to multiply kinds of diseases. Although differentially expressed circRNA profiling in Alzheimer's disease (AD) has been established, little is known about the precise characteristic and functions of key circRNAs with direct relevance to AD in gene expression and disease-related cognition. Herein, we screened and identified circCwc27 as a novel circRNA implicated in AD. CircCwc27 was a neuronal-enriched circRNA that abundantly expressed in the brain and significantly upregulated in AD mice and patients. Knockdown of circCwc27 markedly improved AD-related pathological traits and ameliorated cognitive dysfunctions. Mechanistically, we excluded the miRNA decoy mechanism and focused on the important function of circRNA-RNA-binding protein (RBP) interaction in AD. CircCwc27 directly bound to purine-rich element-binding protein A (Pur-α), increased retention of cytoplasmic Pur-α, and suppressed Pur-α recruitment to the promoters of a cluster of AD genes, including amyloid precursor protein (APP), dopamine receptor D1 (Drd1), protein phosphatase 1, regulatory inhibitor subunit1B (Ppp1r1b), neurotrophic tyrosine kinase, receptor, type 1 (Ntrk1), and LIM homeobox 8 (Lhx8). Downregulation of circCwc27 enhanced the affinity of Pur-α binding to these promoters, leading to altered transcription of Pur-α targets. Moreover, Pur-α overexpression largely phenocopied circCwc27 knockdown in preventing Aß deposition and cognitive decline. Together, our findings suggest significant functional consequences of a circRNA-protein interaction, that circCwc27, by associating with the regulatory protein Pur-α, may act as a crucial player in AD pathogenesis and represent a promising AD therapeutic target with clinical translational potential.

Post-transcriptional regulation of α7 nAChR expression by miR-98-5p modulates cognition and neuroinflammation in an animal model of Alzheimer's disease.

Alzheimer's disease (AD) is a complicated neurodegenerative disease and therefore addressing multiple targets simultaneously has been believed as a promising therapeutic strategy against AD. α7 nicotinic acetylcholine receptor (nAChR), which plays an important role in improving cognitive function and alleviating neuroinflammation in central nervous system (CNS), has been regarded as a potential target in the treatment of AD. However, the regulation of α7 nAChR at post-transcriptional level in mammalian brain remains largely speculated. Herein, we uncovered a novel post-transcriptional regulatory mechanism of α7 nAChR expression in AD and further demonstrated that miR-98-5p suppressed α7 nAChR expression through directly binding to the 3'UTR of mRNA. Knockdown of miR-98-5p activated Ca2+ signaling pathway and consequently reversed cognitive deficits and Aß burden in APP/PS1 mice. Furthermore, miR-98-5p downregulation increased α7 nAChR expression, and ameliorated neuroinflammation via inhibiting NF-κB pathway and upregulating Nrf2 target genes. Our findings illustrate a prominent regulatory role of miR-98-5p in targeting inflammation and cognition, and provide an insight into the potential of miR-98-5p/α7 nAChR axis as a novel therapeutic strategy for AD.

Kir6.2 Deficiency Promotes Mesencephalic Neural Precursor Cell Differentiation via Regulating miR-133b/GDNF in a Parkinson's Disease Mouse Model.

The loss of dopaminergic (DA) neurons in the substantia nigra (SN) is a major feature in the pathology of Parkinson's disease (PD). Using neural stem or progenitor cells (NSC/NPCs), the prospect of replacing the missing or damaged DA neurons is very attractive for PD therapy. However, little is known about the endogenous mechanisms and molecular pathways regulating the NSC/NPC proliferation and differentiation in the development of PD. Herein, using Kir6.2 knockout (Kir6.2-/-) mice, we observed that genetic deficiency of Kir6.2 exacerbated the loss of SN DA neurons relatively early in a chronic MPTP/probenecid (MPTP/p) injection course, but rescued the damage of neurons 7 days after the last MPTP/p injection. Meanwhile, we found that Kir6.2 knockout predominantly increased the differentiation of nuclear receptor-related 1 (Nurr1+) precursors to DA neurons, indicating that Kir6.2 deficiency could activate an endogenous self-repair process. Furthermore, we demonstrated in vivo and in vitro that lack of Kir6.2 promoted neuronal differentiation via inhibiting the downregulation of glia cell line-derived neurotrophic factor (GDNF), which negatively related to the level of microRNA-133b. Notably, we revealed that Gdnf is a target gene of miR-133b and transfection of miR-133b could attenuate the enhancement of neural precursor differentiation induced by Kir6.2 deficiency. Collectively, we clarify for the first time that Kir6.2/K-ATP channel functions as a novel endogenous negative regulator of NPC differentiation, and provide a promising neuroprotective target for PD therapeutics.

Salmeterol, agonist of ß2-aderenergic receptor, prevents systemic inflammation via inhibiting NLRP3 inflammasome.

ß2-Aderenergic receptor (ß2AR) agonist, Salmeterol exhibits anti-inflammatory activities. However, the inhibitory effects of Salmeterol on inflammasome activation are elusive and the underlying mechanisms need to be explored. In this study, we established inflammatory model in primary bone marrow-derived macrophages (BMDM) from C57BL/6J mice and ß-arrestin2 knockout (ß-arrestin2-/-) mice in vitro. In vivo study by LPS intraperitoneally (i.p.) in C57BL/6J mice was carried out to ascertain its roles in systemic inflammation. We found that Salmeterol (10-10 M-10-7 M) prevented the cleavage of caspase-1 and the activation of NLRP3 inflammasome, reduced the release of pro-inflammatory cytokines tumor necrosis factor-α (TNF-α) and interleukin-1ß (IL-1ß) in vitro. Blockade of adenosine3',5'cyclic monophosphate (cAMP)/protein kinase A (PKA) pathway with cAMP or PKA inhibitors inhibited anti-inflammatory effects of Salmeterol only at 10-7 M. Depletion of ß-arrestin2 compromised the inhibitory effects of Salmeterol at both 10-10 M and 10-7 M. Salmeterol increased the interaction of ß-arrestin2 and NLRP3. In vivo study showed that Salmeterol decreased the serum concentrations of pro-inflammatory cytokines IL-1ß and TNF-α, blocked cleavage of caspase-1 and release of IL-1ß in BMDM. These findings imply that Salmeterol at low concentrations (10-10 M-10-7 M) shows anti-inflammatory effect via inhibiting NLRP3 inflammasome. The underlying mechanisms is dosage-dependent: Salmeterol at 10-10 M shows anti-inflammatory effects through ß-arrestin2 pathway, and 10-7 M Salmeterol inhibits inflammation via both classical G-protein coupled receptor (GPCR)/cAMP pathway and ß-arrestin2 pathway. These results provide new ideas for the future treatment of systemic inflammation and other inflammatory diseases.