ABSTRACT
BACKGROUND: Alzheimer's disease (AD) is a neurodegenerative disease featured by memory loss, neuroinflammation and oxidative stress. Overproduction or insufficient clearance of Aß leads to its pathological aggregation and deposition, which is considered the predominant neuropathological hallmark of AD. Therefore, reducing Aß levels and inhibiting Aß-induced neurotoxicity are feasible therapeutic strategies for AD treatment. Wolfberry has been traditionally used as a natural antioxidant and anti-aging product. However, whether wolfberry species has therapeutic potential on AD remains unknown. METHOD: The effects of fruitless wolfberry-sprout extract (FWE) on Aß fibrillation and fibril disaggregation was measured by thioflavin T fluorescence and transmission electron microscope imaging; Aß oligomer level was determined by dot-blot; Cell viability and apoptosis was assessed by MTT and TUNEL assay. The levels of Aß40/42, oxidative stress biomarkers and inflammatory cytokines were detected by corresponding kits. 8-month-old male APP/PS1 mice and their age-matched WT littermates were treated with FWE or vehicle by oral administration (gavage) once a day for 4 weeks. Then the cognitive performance was determined using object recognition test and Y-maze test. The Aß burden and gliosis was evaluated by immunostaining and immunoblotting, respectively. RESULTS: FWE significantly inhibited Aß fibrillation and disaggregated the formed Aß fibrils, lowered Aß oligomer level and Aß-induced neuro-cytotoxicity, and attenuated oxidative stress in vitro. Oral administration of FWE remarkably improved cognitive function, reduced Aß burden, decreased gliosis and inflammatory cytokines release, and ameliorated oxidative stress in the brains of APP/PS1 mice. CONCLUSION: These findings indicate that FWE is a promising natural agent for AD treatment.
Subject(s)
Alzheimer Disease/complications , Cognition Disorders/drug therapy , Cognition Disorders/etiology , Lycium/chemistry , Plant Extracts/therapeutic use , Alzheimer Disease/genetics , Alzheimer Disease/pathology , Amyloid beta-Peptides/metabolism , Amyloid beta-Protein Precursor/genetics , Animals , Brain/metabolism , Brain/pathology , Calcium-Binding Proteins/metabolism , Disease Models, Animal , Glial Fibrillary Acidic Protein/metabolism , Glutathione/metabolism , Glutathione Disulfide/metabolism , Interleukin-6/metabolism , Maze Learning/drug effects , Mice , Mice, Inbred C57BL , Mice, Transgenic , Microfilament Proteins/metabolism , Mutation/genetics , Oxidative Stress/drug effects , Peptide Fragments/metabolism , Presenilin-1/genetics , Recognition, Psychology/drug effects , Superoxide Dismutase/metabolism , Tumor Necrosis Factor-alpha/metabolismABSTRACT
Beta-amyloid (Aß) aggregates have a pivotal role in pathological processing of Alzheimer's disease (AD). The clearance of Aß monomer or aggregates is a causal strategy for AD treatment. Microglia and astrocytes are the main macrophages that exert critical neuroprotective roles in the brain. They may effectively clear the toxic accumulation of Aß at the initial stage of AD, however, their functions are attenuated because of glial overactivation. In this study, we first showed that heptapeptide XD4 activates the class A scavenger receptor (SR-A) on the glia by increasing the binding of Aß to SR-A, thereby promoting glial phagocytosis of Aß oligomer in microglia and astrocytes and triggering intracellular mitogen-activated protein kinase (MAPK) signaling cascades. Moreover, XD4 enhances the internalization of Aß monomers to microglia and astrocytes through macropinocytosis or SR-A-mediated phagocytosis. Furthermore, XD4 significantly inhibits Aß oligomer-induced cytotoxicity to glial cells and decreases the production of proinflammatory cytokines, such as TNF-α and IL-1ß, in vitro and in vivo. Our findings may provide a novel strategy for AD treatment by activating SR-A.
Subject(s)
Amyloid beta-Peptides/metabolism , Astrocytes/metabolism , Microglia/metabolism , Peptide Fragments/metabolism , Peptides/pharmacology , Receptors, Scavenger/physiology , Scavenger Receptors, Class A/physiology , Animals , Astrocytes/drug effects , Astrocytoma/pathology , Cell Line , Cell Line, Tumor , Cells, Cultured , Cerebral Cortex/cytology , Drug Evaluation, Preclinical , Humans , Interleukin-1beta/metabolism , Membrane Proteins/metabolism , Mice , Microglia/drug effects , Phagocytosis/drug effects , Rats , Tumor Necrosis Factor-alpha/metabolismABSTRACT
A full-length cDNA, BcMF11, has been cloned from Chinese cabbage (Brassica campestris L. ssp. chinensis Makino) using rapid amplification of the cDNA ends (RACE) based on a pollen-specific cDNA fragment (DN237921). The BcMF11 cDNA has a total length of 828bp with poly (A) tail. Analysis of the sequence demonstrated that BcMF11 is a novel non-coding RNA which has no prominent open reading frame (ORF) or coding capacity. No significant similarities were observed between BcMF11 and previously published sequences in GenBank. Transcription analysis indicated that BcMF11 is a novel pollen-specific ncRNA and may be involved in the pollen development of Chinese cabbage.