Loss of ESRP1 blocks mouse oocyte development and leads to female infertility.

Alternative splicing (AS) contributes to gene diversification, but the AS program during germline development remains largely undefined. Here, we interrupted pre-mRNA splicing events controlled by epithelial splicing regulatory protein 1 (ESRP1) and found that it induced female infertility in mice. Esrp1 deletion perturbed spindle organization, chromosome alignment and metaphase-to-anaphase transformation in oocytes. The first polar body extrusion was blocked during oocyte meiosis owing to abnormal activation of spindle assembly checkpoint and insufficiency of anaphase-promoting complex/cyclosome in Esrp1-knockout oocytes. Esrp1-knockout hampered follicular development and ovulation; eventually, premature ovarian failure occurred in six-month-old Esrp1-knockout mouse. Using single-cell RNA-seq analysis, 528 aberrant AS events of maternal mRNA transcripts were revealed and were preferentially associated with microtubule cytoskeletal organization. Notably, we found that loss of ESRP1 disturbed a comprehensive set of gene-splicing sites - including those within Trb53bp1, Rac1, Bora, Kif2c, Kif23, Ndel1, Kif3a, Cenpa and Lsm14b - that potentially caused abnormal spindle organization. Collectively, our findings provide the first report elucidating the ESRP1-mediated AS program of maternal mRNA transcripts, which may contribute to oocyte meiosis and female fertility in mice.

Tissue-resident CXCR4+ macrophage as a poor prognosis signature promotes pancreatic ductal adenocarcinoma progression.

Macrophage is an essential part of the tumor immune microenvironment of pancreatic ductal adenocarcinoma. In our study, we explored the CXCR4+ macrophages subset on its prognosis value, immune profile and distinct function in pancreatic cancer progression. Specimens from 102 postoperative pancreatic patients were analyzed by flow cytometry or immune-fluorescence, and the prognostic value of CXCR4+ macrophages infiltration was further determined by Cox regression. In silico analysis on TCGA, ICGC database and single-cell sequencing of pancreatic ductal adenocarcinoma further validated our findings. We found that high CXCR4+ macrophages infiltration was associated with poor overall survival (P < .01) and disease-free survival (P < .05) as an independent factor. CXCR4+ macrophages exhibited an M2 protumor phenotype with high expression of CD206. The function of CXCR4+ macrophages was further analyzed in the murine orthotopic PDAC model with its tumor promotion effect and inhibition of CD8+ T cells. Mechanistic and RNA-seq analysis showed that CXCR4+ macrophages participated in extracellular matrix remodeling procedures and especially secreted SPARC through CXCR4/PI3K/Akt pathway promoting tumor proliferation and migration. Our study reveals that CXCR4+ macrophages infiltration is an indicator of poor prognosis of PDAC and targeting these cells was potentially crucial in immunotherapy of PDAC.

First Report of Nigrospora hainanensis Causing Leaf Blight on Brachiaria Griseb in China.

Brachiaria Griseb is an important gramineous forage grown in tropical regions, and also a main grass species uses to restore grasslands in tropical and subtropical regions of China. In August 2022, symptoms of leaf blight were observed on nearly 30% of the Brachiaria forage grass in the base of the Chinese Academy of Tropical Agricultural Sciences, Hainan, China. Symptomatic leaves initially exhibited small, reddish-brown, round or oval spots on their tips, subsequently expanding in size along the leaf margin, and gradually becoming wilted and dry. Twenty leaves showing typical symptoms were randomly collected and pieces (5×5 mm) from the junction of diseased and healthy region were cut, sterilized with 75% alcohol for 30 s, followed by 5% sodium hypochlorite for 30 s. Rinsed three times with sterile water and dried with sterile filter paper. Leaf pieces were placed on potato dextrose agar (PDA) and incubated at 28℃. The colonies were white on the surface and gray on the reverse side. The conidiogenous cells were monoblastic, hyaline, globose or ampulliform, and 6 to 8.7(13.1) ×5 to 7.2 (9) m (n=200). Conidia is single celled, smooth, black, spherical, or ellipsoidal, and (11)13 to 16.5 × (8.2) 10.3 to16.1 m (n=100). Setae were not observed. The morphological characteristics of the isolates were consistent with Nigrospora species. A representative isolate (LNH-5) was selected for genomic DNA extraction. Sequences of the transcribed spacer region of rDNA (ITS), partial translation elongation factor (TEF1), and beta-tubulin fragment (TUB) were amplified using primer pairs ITS1/ITS4(White et al. 1990), EF-728F and EF-986R (Carbone et al. 1999) and Bt2a and Bt2b (Glass et al. 1995), respectively. The sequences of ITS (OQ473493), TEF1 (OQ506059) and TUB gene (OQ506055) were submitted to GenBank. They were 99 to 100% identical to the Nigrospora hainanensis ITS(OM283581.1)(538 out of 519 bp),TEF1(YK019415.1)(274 out of 276 bp),and TUB (OK086377.1)(405 out of 405 bp) sequences. The phylogenetic maximum likelihood analysis using the combined ITS, TEF1 and TUB sequences indicated that the isolate was part of the N. hainanensis clade (100% bootstrap value) that also contained the type isolate LC6979 of this species. Pathogenicity was tested on 15 healthy Brachiaria plants. Fungal conidia were harvested by flooding two-week-old single conidial cultures with sterile water, centrifuging, and adjusting the concentration to 107 spores/mL. Then 10 µL of conidial suspension was dropped onto the surfaces of leaves wounded with a sterile needle. Sterile distilled water was used for control treatment. The test was repeated three times. After inoculation, the plants were kept at 90~100% relative humidity at 25 to 28°C in a greenhouse for two weeks, and monitored daily for lesion development. Seven days post inoculation, all the inoculated leaves presented symptoms similar to those observed under natural conditions, while the control leaves showed no symptoms. The fungus was re-isolated from the diseased tissues by the single spore isolation method (Choi et al. 1999) to complete Koch's postulates. This pathogen has been reported on sugarcane in China (Raza et al., 2019; Zheng et al., 2022). To our knowledge, this is the first report of N. hainanensis causing leaf blight on Brachiaria plants in China.

Binding properties of odorant-binding protein 4 from bean bug Riptortus pedestris to soybean volatiles.

The bean bug Riptortus pedestris is a notorious insect pest that can damage various crops, especially soybean, in East Asia. In insects, the olfactory system plays a crucial role in host finding and feeding behaviour in which the odorant-binding proteins (OBPs) are believed to be involved in initial step in this system. In this study, we produced the R. pedestris adult antennae-expressed RpedOBP4 protein using a recombinant expression system in E. coli. Fluorescence competitive binding confirmed that RpedOBP4 has binding affinities to 7 of 20 soybean volatiles (ligands), and that a neutral condition is the best environment for it. The binding property of RpedOBP4 to these ligands was further revealed by integrating data from molecular docking, site-directed mutagenesis and ligand binding assays. This demonstrated that five amino acid residues (I30, L33, Y47, I57 and Y121) are involved in the binding process of RpedOBP4 to corresponding ligands. These findings will not only help us to more thoroughly explore the olfactory mechanism of R. pedestris during feeding on soybean, but also lead to the identification of key candidate targets for developing environmental and efficient behaviour inhibitors to prevent population expansion of R. pedestris in the future.

Intrinsic Regularity of Catalytic Cobalt Chalcogenides in Lithium-Sulfur Battery: Theoretical Study Delivers New Insights.

Cobalt chalcogenides CoX2 (X=S, Se, Te) render great performance of lithium-sulfur batteries based on catalytic capacity to alleviate shuttle effect. Given that S/Se/Te belong to the same main group, the outstanding cycling stability delivered by CoTe2 aroused the curiosity about the uniqueness of CoTe2 and intrinsic laws of cobalt chalcogenide. Herein, comprehensive theoretical study delivers new insights into the intrinsic laws of CoX2 : the relative vertical distance of two X atomic layers (rather than atom electronegativity) mainly controls adsorption; CoX2 mainly regulates the charging process (rather than discharging process) thus contributes to great cycling stability. On this basis, the advantages of CoTe2 are three-fold: moderate polysulfide adsorption, facile ion transport capacity, and surprisingly great promotion of charging process. It is hope the results will facilitate the development of cobalt chalcogenides, especially tellurides as catalytic material in lithium sulfur batteries.

Antagonistic activity of selenium-enriched Bifidobacterium breve against Clostridioides difficile.

Probiotics have the potential to be used in the prevention of Clostridioides difficile infection (CDI). In this study, selenium (Se)-enriched Bifidobacterium breve YH68-Se was obtained under optimal culture conditions with single-factor and response surface optimization. The overall environmental resistance of YH68-Se was superior to that of the parental strain YH68, mainly reflected in the substantial improvement of antioxidant activity and gastrointestinal tolerance. YH68-Se dramatically inhibited C. difficile growth, spore, biofilm, toxin production, and virulence gene expression, rapidly disrupted C. difficile cell membrane permeability and integrity, and altered the membrane proton motive force (PMF), induced a large outflow of intracellular substances and eventually caused bacterial death. The main factor inducing this process originated from the lactic acid (LD) in YH68-Se. In addition, the LD production of YH68 increased with increasing selenite concentration and was accompanied by enhanced activities of thioredoxin reductase (TrxR), glutathione peroxidase (GSH-Px), and increased concentration of autoinducer-2 (AI-2), which may be the crucial factors contributing to the outstanding probiotic properties of YH68-Se and their potent antagonism of C. difficile. KEY POINTS: • Compared with the parental strain B. breve YH68, the environmental resistance of YH68-Se was improved. • YH68-Se was able to produce more lactic acid, which suppressed the important physiological activities of C. difficile and rapidly disrupted their cell membrane structures. • Sodium selenite in the suitable concentration range gradually increases the yield of lactic acid and phenylacetic acid, increased the concentration of autoinducer-2, and enhanced the activities of antioxidant enzymes TrxR and GSH-Px in YH68.

Structural length-scale of ß relaxation in metallic glass.

Establishing the structure-property relationship is an important goal of glassy materials, but it is usually impeded by their disordered structure and non-equilibrium nature. Recent studies have illustrated that secondary (ß) relaxation is closely correlated with several properties in a range of glassy materials. However, it has been challenging to identify the pertinent structural features that govern it. In this work, we show that the so-called polyamorphous transition in metallic glasses offers an opportunity to distinguish the structural length scale of ß relaxation. We find that, while the glass transition temperature and medium-range orders (MROs) change rapidly across the polyamorphous transition, the intensity of ß relaxation and the short-range orders (SROs) evolve in a way similar to those in an ordinary reference glass without polyamorphous transition. Our findings suggest that the MRO accounts mainly for the global stiffening of the materials and the glass transition, while the SRO contributes more to ß relaxation per se.

Characterization and Antioxidant Activity of Mannans from Saccharomyces cerevisiae with Different Molecular Weight.

Polysaccharides were extracted from natural sources with various biological activities, which are strongly influenced by their chemical structure and molecular weight. In this research, mannans polysaccharides were obtained from Saccharomyces cerevisiae by ethanol precipitation. The molecular weight of YM50, YM70, and YM90 mannans was 172.90 kDa, 87.09 kDa, and 54.05 kDa, respectively. Scanning electron microscopy of YM 90 mannans showed a rough surface with numerous cavities, while the surfaces of YM50 and YM70 were relatively smooth. Sepharose CL-6B and FTIR indicated that mannans had the characteristic bands of polysaccharides. The antioxidant activities of polysaccharides were evaluated in vitro using various assays. Mannans showed a good scavenging activity of DPPH radicals which depend on the molecular weight and concentration, and a higher scavenging activity of hydroxyl radical than ferric-reducing power activities. For the three types of mannans, cytotoxicity and hemolytic activity were rarely detected in mice erythrocytes and Caco-2 cells. Those results could contribute to the further application of mannans from Saccharomyces cerevisiae in the food and medicine industry.

Study on sampling scheme for detecting mycotoxin during wheat storage.

BACKGROUND: Mycotoxin produced by mould is one of the most serious contamination sources in food security. Safe storage of grain has become more important to control food security. Currently, there is no officially approved or standardized sampling scheme for detecting mycotoxin in grain storage worldwide. RESULTS: In this study, deoxynivalenol (DON) was taken as a typical mycotoxin in stored wheat to be detected. Population density of corn weevil could not significantly increase wheat moisture, but wheat moisture was highly significantly and positively correlated with DON content (P < 0.01). Corn weevil density significantly increased the DON content in wheat. DON contamination degree was mainly distributed in the region of 14-20 cm below the surface layer of wheat. In the process of ventilation and dehumidification during the storage period, moisture of wheat decreased slightly with the extension of ventilation, but the DON content in wheat increased significantly. Combined with the analysis of ventilation, DON content in the upper layer and H1 position, where the wind direction is not easy to reach, increased significantly. CONCLUSION: Areas with high insect population density (14-20 cm below the surface layer of stored wheat) and low ventilation and high humidification (H1 position in the upper layer) should be taken as the key cutting sample areas for detecting mycotoxin during the period of grain storage. This study provides for the first time a scientific basis for the standardization of the wheat sampling scheme to monitor mycotoxin contamination during wheat storage. © 2022 Society of Chemical Industry.

One-Pot Synthesis of Chromone-Fused Pyrrolo[2,1-a]isoquinolines and Indolizino[8,7-b]indoles: Iodine-Promoted Oxidative [2 + 2 + 1] Annulation of O-Acetylphenoxyacrylates with Tetrahydroisoquinolines and Noreleagnines.

An iodine-promoted one-pot cascade oxidative annulation reaction has been developed for the synthesis of chromone-fused-pyrrolo[2,1-a]isoquinolines and indolizino[8,7-b]indoles from o-acetylphenoxyacrylates, tetrahydroisoquinolines, and noreleagnines. This process underwent a logical approach to both chromone-fused-pyrrolo[2,1-a]isoquinolines and chromone-fused-indolizino[8,7-b]indoles isolamellarin derivatives. Manipulations of l-menthol and dl-α-tocopherol demonstrate the applications of this strategy.

Cascade Wolff Rearrangement/Acylation: A Metal-Free and Eco-Friendly Approach for 4-Hydroxy-pyrazolo[3,4-b]pyridin-6-ones and N-Pyrazole Amides Synthesis from 5-Aminopyrazoles and α-Diazoketones.

A highly chemoselective cascade Wolff rearrangement/acylation reaction between 5-aminopyrazoles and diazo compounds has been developed. The protocol can facilitate the switchable synthesis of 4-hydroxy-pyrazolo[3,4-b]pyridin-6-ones and N-pyrazole amides with the merits of a broad substrate scope, high functional group compatibility, and green and sustainable performance manner. All reactions proceeded efficiently without any catalyst and additives (acid and base) and resulted in the release of benign N2, wherein diethyl carbonate served as a green benign solvent.

Primary research on sampling scheme for analyzing mycotoxin distribution in wheat and rice fields.

BACKGROUND: Mycotoxins are among the most severe food contaminants. Deoxynivalenol and aflatoxin contamination are predominant in wheat and rice, respectively. Nowadays, there are no standardized and approved grain-sampling schemes worldwide. This study aimed to develop a scientific grain-sampling scheme to investigate the regularity of mycotoxin distributed in wheat and rice fields. The data were analyzed with analysis of variance and cluster analysis to select a better sampling scheme. RESULTS: Considering the influences of the weather before harvest (temperature, humidity, wind direction, and other conditions), we sampled grains from different places in different farmlands and detected the mycotoxin content of the sampled grains. The mycotoxin content had extremely significant differences in the area of rice fields (P<0.01) and significant differences in the area of wheat fields (P<0.05). The filtering effect existed peripheral the field areas, especially peripheral the humid areas, where the fungi were filtered and the toxin were easily produced. Furthermore, the upwind direction peripheral the field areas cause more filterature effect than other wind direction. Although 97% of mycotoxins in wheat can be removed through the shelling process, the toxin content were not obviously affected by rice lodging in the field. According to the cluster analysis, the peripheral and middle areas were divided into the same group with higher mycotoxin content. CONCLUSION: This paper developed a sampling scheme to detect the mycotoxin content of wheat and rice in the field, considering the temperature and humidity of the weather, locations, and other grain contamination conditions before harvest. Meanwhile, the sampling rule of lodging and wind direction in the field was also assayed. © 2021 Society of Chemical Industry.

Increasing soluble dietary fiber content and antioxidant activity of wheat bran through twin-screw extrusion pretreatment.

As a by-product during flour production, wheat bran is mainly used as raw material for fodder or fermentation. In the present work, wheat bran was extruded with different moisture conditions and the consequently chemical component, absorption capacity, and antioxidant activity of treated wheat bran were analyzed. Results showed that extrusion decreased the particle size and crystallinity of wheat bran, but increased the soluble dietary fiber content of which from 3.08% to 11.78%. Meanwhile, water holding capacity, oil holding capacity for peanut oil and lard, and swelling capacity of WB-W-G-Na reached 5.67 g/g, 3.34 g/g, 3.58 g/g and 4.3 mL/g, respectively. Moreover, DPPH radical scavenging activity of WB-W-G-Na increased from 6.8% to 18.4% and hydroxyl radical scavenging activity increased from 5.3% to 15.9%. Overall, this work provides an excellent pretreatment method for increasing the functional activities of wheat bran in the food industry.

Polar-π Interactions Promote Self-assembly of Dipeptides into Laminated Nanofibers.

Precise incorporation of functional residues into sequences allows for tailoring the noncovalent interactions between peptides to guide their self-assembly into well-defined nanostructures, thus facilitating creation of artificial functional materials resembling natural systems. Here, we report on the self-assembly of dipeptides consisting of one fluorinated phenylalanine unit (Z residue) and one natural aromatic residue into laminated nanofibers predominately driven by polar-π interactions. On the basis of characterizations using transmission electron microscopy, scanning electron microscopy, atomic force microscopy, circular dichroism, Fourier transform infrared spectroscopy, and thioflavin T binding assay, we found that the face-centered stacking pattern of the dipeptides FZ, ZF, and ZY stabilized by the polar-π interactions and antiparallel ß-sheet H-bonding interactions led to lamination of nanofibers and formation of ribbonlike nanostructures. Our findings demonstrate that incorporation of fluorinated aromatic units into short peptides not only promotes of polar-π interactions as alternative self-assembling driving forces but also governs the organizing pattern of peptides, thus benefiting creation of well-defined peptide nanostructures.

Enrichment and Distribution of Pb2+ Ions in Zwitterionic Poly(cysteine methacrylate) Brushes at the Solid-Liquid Interface.

Cysteine-based polyzwitterionic brushes have been prepared via a two-step route. First, poly(allyl methacrylate) (PAMA) brushes have been grown from the surface of silicon substrates using surface-initiated atom transfer radical polymerization. The obtained PAMA brushes with free pendant vinyl groups were further modified via radical thiol-ene addition reaction to attach l-cysteine moieties. Surface ζ potential investigations on pH-responsiveness of these poly(cysteine methacrylate) (PCysMA) brushes confirm their zwitterionic character at intermediate pH range, while at pH values either below pH 3.50 or above pH 8.59, they exhibit polyelectrolyte character. Under acid (pH < 3.50) or base (pH > 8.59) conditions, they possess either cationic or anionic character, respectively. In the zwitterionic region, these PCysMA brushes show positive surface ζ potential in the presence of Pb(CH3COO)2 solutions of various concentrations. The results are in line with microscopic investigations using anomalous X-ray reflectivity (AXRR) carried out along the absorption edge of Pb2+ ions. When the photon energies were varied around the absorption L3 edge of lead (13037 eV), the Pb2+ concentration normal to the silicon substrates, as a function of depth inside PCysMA brushes, could be revealed at the nanoscale. Both ζ potential and AXRR measurements confirm the enrichment of Pb2+ ions inside PCysMA brushes, indicating the potential of PCysMA to be used as a water purification material.

Critical Role of Trophic Factors in Protecting Müller Glia: Implications to Neuroprotection in Age-Related Macular Degeneration, Diabetic Retinopathy, and Anti-VEGF Therapies.

The concept that Müller glia (MG) are major retinal supporting cells for neuroprotection under various stresses is well established. However, the detailed molecular and cellular mechanisms of MG-mediated neuroprotection remain elusive. Particularly, the role and mechanism of MG in neuroprotection under diabetic and hypoxic stresses are largely unknown. In this article, we will discuss the role and mechanisms of a major growth factor, vascular endothelial growth factor (VEGF), in mediating MG viability and its potential impact on neuronal integrity in diabetes and hypoxia, demonstrate results on alternative mechanisms to VEGF signaling for MG and neural protection, and highlight the relevance of our work to the treatment of neovascular age-related macular degeneration, diabetic retinopathy, wet age-related macular degeneration, and other hypoxic retinal vascular diseases.

Efficient production of polysaccharide by Chaetomium globosum CGMCC 6882 through co-culture with host plant Gynostemma pentaphyllum.

Endophytic fungus, as a new kind of microbial resources and separated from plants, has attracted increasing attention due to its ability to synthesize the same or similar bioactive secondary metabolites as the host plants. Nevertheless, the effects of the symbiotic relationship between microorganisms and elicitors existed in host plant on metabolite production are not adequately understood. In the present work, the impacts of elicitors (ginseng saponin and puerarin) and symbiotic microorganisms on endophytic fungus Chaetomium globosum CGMCC 6882 synthesizing polysaccharide were evaluated. Results show that the polysaccharide titers increased from 2.36 to 3.88 g/L and 3.67 g/L with the addition of 16 µg/L ginseng saponin and puerarin, respectively. Moreover, the maximum polysaccharide titer reached 4.55 g/L when C. globosum CGMCC 6882 was co-cultured with UV-irradiated G. pentaphyllum. This work brings a significant contribution to the research and interpretation of the relationship between endophytic fungus and its host plant.

Utilization of glycerol and crude glycerol for polysaccharide production by an endophytic fungus Chaetomium globosum CGMCC 6882.

Crude glycerol is becoming a financial and environmental liability due to its surplus production from biodiesel industry, and its utilization as a fermentation feedstock for value-added chemicals production has been widely studied. In present work, the capacity of an endophytic fungus, Chaetomium globosum CGMCC 6882, using glycerol and crude glycerol for polysaccharide production was investigated. Results showed that the polysaccharide titers from glucose and glycerol were 1.85 and 3.8 g/L, respectively. Moreover, spore morphology of C. globosum CGMCC 6882 was favorable for polysaccharide production. Meanwhile, impurities in crude glycerol have no effect on polysaccharide production by C. globosum CGMCC 6882. Finally, characteristic results of polysaccharides produced from glucose, glycerol, and crude glycerol have suggested that metabolic flux might be a determinant factor on polysaccharide structure. Taken together, this research provided an innovative approach of utilizing crude glycerol produced from the biodiesel production process.

Biocatalytic Membrane Based on Polydopamine Coating: A Platform for Studying Immobilization Mechanisms.

Application of biocatalytic membrane is promising in food, pharmaceutical, and water treatment industries, whereas enzyme immobilization is the key step of biocatalytic membrane preparation. Thus, how to minimize the negative effect of immobilization on enzyme performance is required to answer. In this work, we proposed a platform for biocatalytic membrane preparation and immobilization mechanism investigation based on polydopamine (PDA) coating, which was demonstrated by immobilizing five commonly used enzymes (laccase, glucose oxidase, lipase, pepsin, and dextranase) on three commercially available membranes via three immobilization mechanisms (electrostatic attraction, covalent bonding, and hydrophobic adsorption), respectively. By examining the enzyme loading, activity, and kinetics under different immobilization mechanisms, we found that except for dextranase, enzyme immobilization via electrostatic attraction retained the most activity, whereas covalent bonding and hydrophobic adsorption were detrimental to enzyme conformation. Enzyme immobilization via covalent bonding ensured a high enzyme loading, and hydrophobic adsorption was only suitable for lipase and dextranase immobilization. Moreover, the properties of functional groups around the enzyme active center should be considered for the selection of suitable immobilization strategy (i.e., avoid covering the active center by membrane carrier). This work not only established a versatile platform for biocatalytic membrane preparation but also provided a novel methodology to evaluate the effect of immobilization mechanisms on enzyme performance.

Puerarin protects against ß-amyloid-induced microglia apoptosis via a PI3K-dependent signaling pathway.

Puerarin extracted from Radix puerariae is well-known for its anti-oxidative and neuroprotective activities. In this study, we investigated the protective effect of puerarin on amyloid-ß protein (Aß)-induced cytotoxicity and its potential mechanisms in BV-2 and primary microglial cells. We found that pretreatment with puerarin afforded protection against Aß-induced cytotoxicity through inhibiting apoptosis in BV-2 and primary microglial cells. This result was also confirmed by the activated caspase-3 assay. Phospho-Akt and Bcl-2 expression increased after pretreatment with puerarin in BV-2 and primary microglial cells exposed to Aß, whereas Bax expression and cytochrome c release decreased. In addition, puerarin treatment prevented the loss of mitochondrial membrane potential and reactive oxygen species production. Interestingly, these effects of puerarin against Aß insult were abolished by LY294002, an inhibitor of PI3K phosphorylation. Taken together, these findings suggest that puerarin prevents Aß-induced microglial apoptosis via the activation of PI3K/Akt signaling pathway, and might be a potential preventive or therapeutic agent for Alzheimer's disease.