Fatty acid metabolism promotes TRPV4 activity in lung microvascular endothelial cells in pulmonary arterial hypertension.

Pulmonary arterial hypertension (PAH) is a morbid disease characterized by significant lung endothelial cell (EC) dysfunction. Prior work has shown that microvascular endothelial cells (MVECs) isolated from animals with experimental PAH and patients with PAH exhibit significant abnormalities in metabolism and calcium signaling. With regards to metabolism, we and others have shown evidence of increased aerobic glycolysis and evidence of increased utilization of alternate fuel sources (such as fatty acids) in PAH EC. In the realm of calcium signaling, our prior work linked increased activity of the transient receptor potential vanilloid-4 (TRPV4) channel to increased proliferation of MVECs isolated from the Sugen/Hypoxia rat model of PAH (SuHx-MVECs). However, the relationship between metabolic shifts and calcium abnormalities was not clear. Specifically, whether shifts in metabolism were responsible for increasing TRPV4 channel activity in SuHx-MVECs was not known. In this study, using human data, serum samples from SuHx rats, and SuHx-MVECs, we describe the consequences of increased MVEC fatty acid oxidation in PAH. In human samples, we observed an increase in long-chain fatty acid levels that was associated with PAH severity. Next, using SuHx rats and SuHx-MVECs, we observed increased intracellular levels of lipids. We also show that increasing intracellular lipid content increases TRPV4 activity, whereas inhibiting fatty acid oxidation normalizes basal calcium levels in SuHx-MVECs. By exploring the fate of fatty acid-derived carbons, we observed that the metabolite linking increased intracellular lipids to TRPV4 activity was ß-hydroxybutyrate (BOHB), a product of fatty acid oxidation. Finally, we show that BOHB supplementation alone is sufficient to sensitize the TRPV4 channel in rat and mouse MVECs. Returning to humans, we observe a transpulmonary BOHB gradient in human patients with PAH. Thus, we establish a link between fatty acid oxidation, BOHB production, and TRPV4 activity in MVECs in PAH. These data provide new insight into metabolic regulation of calcium signaling in lung MVECs in PAH.NEW & NOTEWORTHY In this paper, we explore the link between metabolism and intracellular calcium levels in microvascular endothelial cells (MVECs) in pulmonary arterial hypertension (PAH). We show that fatty acid oxidation promotes sensitivity of the transient receptor potential vanilloid-4 (TRPV4) calcium channel in MVECs isolated from a rodent model of PAH.

Diosbulbin C, a novel active ingredient in Dioscorea bulbifera L. extract, inhibits lung cancer cell proliferation by inducing G0/G1 phase cell cycle arrest.

BACKGROUND: Despite the critical progress of non-small cell lung cancer (NSCLC) therapeutic approaches, the clinical outcomes remain considerably poor. The requirement of developing novel therapeutic interventions is still urgent. In this study, we showed for the first time that diosbulbin C, a natural diterpene lactone component extracted from traditional Chinese medicine Dioscorea bulbifera L., possesses high anticancer activity in NSCLC. METHODS: A549 and NCI-H1299 cells were used. The inhibitory effects of the diosbulbin C on NSCLC cell proliferation were evaluated using cytotoxicity, clone formation, EdU assay, and flow cytometry. Network pharmacology methods were used to explore the targets through which the diosbulbin C inhibited NSCLC cell proliferation. Molecular docking, qRT-PCR, and western blotting were used to validate the molecular targets and regulated molecules of diosbulbin C in NSCLC. RESULTS: Diosbulbin C treatment in NSCLC cells results in a remarkable reduction in cell proliferation and induces significant G0/G1 phase cell cycle arrest. AKT1, DHFR, and TYMS were identified as the potential targets of diosbulbin C. Diosbulbin C may inhibit NSCLC cell proliferation by downregulating the expression/activation of AKT, DHFR, and TYMS. In addition, diosbulbin C was predicted to exhibit high drug-likeness properties with good water solubility and intestinal absorption, highlighting its potential value in the discovery and development of anti-lung cancer drugs. CONCLUSIONS: Diosbulbin C induces cell cycle arrest and inhibits the proliferation of NSCLC cells, possibly by downregulating the expression/activation of AKT, DHFR, and TYMS.

Alloprevotella Can be Considered as a Potential Oral Biomarker in Intestinal Metaphase of Gastric Patients.

Gastric cancer is a malignant tumor with high incidence and death rate. Every year, Approximately 950,000 new cases of gastric cancer occur globally with nearly 700000 deaths,so gastric precancerous lesions(GPL) was crucial and important.At present, the effective diagnostic methods for gastric precancerous lesions are generally gastroscope and pathological changes of gastric mucosal, but those methods were invasive and would bring some pains to patients and not suitable for frequent and large-scale screening of gastric cancer or GPL.This study aimed to look for a sensitive,effective and non-invasive diagnostic method to improve the early diagnosis rate of GLP, and thereby reduce the incidence and death rate of gastric cancer.Tongue diagnosis is one of the classic diagnostic methods in traditional Chinese medicine(TCM).The tongue was closely related to the spleen and stomach.In the study, we collected 133 patients with chronic gastritis, including 53 cases in inflammatory group, 31 cases in atrophic group, and 49 cases in intestinal metaplasia group. and we analyzed the correlation between tongue,microbiota of tongue coating and clinical symptoms of GLP.The results showed that greasy coating was closely related to the intestinal metaphase of patients, indicating that greasy coating was closed link with intestinal metaphase phase of patients.Abundance of 209 genus were significant differences between greasy and non-greasy coating in intestinal metaphase phase of patients, Top10 were Streptococcus,norank_p__Saccharibacteria,Alloprevotella, Atopobium, Megasphaera, Gemella, Moraxella,unclassified_f__Prevotellaceae, Solobacterium and Stomatobaculum. Alloprevotella and Streptococcus were important genus markers and Alloprevotella was selected as a potential oral biomarker to diagnose intestinal metaphase phase of patients, the AUC value is 0.74.

Effect of treatment of Fusarium head blight infected barley grains with hop essential oil nanoemulsion on the quality and safety of malted barley.

Fusarium mycotoxin contamination of malting barley has been a persistent food safety issue for malting companies. In this study, the effect of hop essential oil (HEO) nanoemulsion on fungal biomass and mycotoxin production during the malting process was evaluated. Furthermore, the localization of fungal hyphae on the surface and inside the tissue of barley and malts was observed. The application of HEO nanoemulsion reduced fungal biomass and deoxynivalenol (DON) contents at each stage of the malting process as compared to control. During malting process, the fungal hyphae on kernel surfaces was reduced appreciably after steeping. However, the increment of hyphae was observed between the husk and testa layer of barley after germination than raw barley grains. In addition to its antifungal activity, the antioxidant activity of HEO in the treated malts suppressed the formation of aldehydes. This study lays the foundation for the utilization of HEO in the malting industry.

Spatial distribution and comparative analysis of Aconitum alkaloids in Fuzi using DESI-MSI and UHPLC-QTOF-MS.

Aconitum L. poisoning is a major type of poisoning caused by herbal medicines in many countries. However, despite its toxicity, Aconitum L. is still used because of its therapeutic value. Fuzi, the lateral root of Aconitum L., is one of the most important pharmacological parts. It is necessary for rational medication to figure out the types and contents of toxic Aconitum alkaloids (AAs) in Fuzi and its processed products. The present study aims to investigate the spatial distribution of toxic AAs in Fuzi and the quantification of AAs in various processing products through mass spectrometry methods. In this study, desorption electrospray ionization mass spectrometry imaging (DESI-MSI) was used to directly image the sections of raw Fuzi. The results showed a high content of diester alkaloids (DAs) and a relatively uniform distribution in the sections, while the content of monoester alkaloids (MAs) was low and uneven in the sections, distributed in the cortex, epidermis, vascular column, and other parts of the tissues. The content of non-ester alkaloids (NAs) was relatively minimum, and most of the NAs were distributed in the vascular column and the tightly connected cortex of the tissue. To further investigate the difference between raw and processed Fuzi, 60 known compounds were identified using UHPLC-QTOF-MS. The total contents of alkaloids in 7 processed Fuzi were lower than that in Shengfupian (SFP). Paofupian (PFP), Paotianxiong (PTX), Paofupian (PFP*), Danfupian (DFP), and Shufupian (SFP*) were the least similar. Zhengfupian (ZFP) and Chaofupian (CFP) had significantly reduced toxicity and increased efficacy compared with other processed products because the contents of active alkaloids in other processed products were also reduced. Understanding the distribution of metabolites and the composition changes after processing can guide users and herbal manufacturers to carefully choose the relatively safe and better therapeutic species of Fuzi. The information gathered from this study can contribute towards the improved and effective management of therapeutically important, nonetheless toxic, drugs such as Aconitum L.

Involvement of the inhibition of mitochondrial apoptotic, p53, NF-κB pathways and the activation of Nrf2/HO-1 pathway in the protective effects of curcumin against copper sulfate-induced nephrotoxicity in mice.

Chronic copper exposure could cause potential nephrotoxicity and effective therapy strategies are limited. This study investigated the protective effects of curcumin on copper sulfate (CuSO4)-induced renal damage in a mouse model and the underlying molecular mechanisms. Mice were administrated orally with CuSO4 (100 mg/kg per day) in combination with or without curcumin (50, 100 or 200 mg/kg per day, orally) for 28 days. Results showed that curcumin supplementation significantly reduce the Cu accumulation in the kidney tissues of mice and improved CuSO4-induced renal dysfunction. Furthermore, curcumin supplantation also significantly ameliorated Cu exposure-induced oxidative stress and tubular necrosis in the kidneys of mice. Moreover, compared to the CuSO4 alone group, curcumin supplementation at 200 mg/kg per day significantly decreased CuSO4-induced the expression of p53, Bax, IL-1ß, IL-6, and TNF-α proteins, levels of NF-κB mRNA, levels of caspases-9 and - 3 activities, and cell apoptosis, and significantly increased the levels of Nrf2 and HO-1 mRNAs in the kidney tissues. In conclusion, for the first time, our results reveal that curcumin could trigger the inhibition of oxidative stress, mitochondrial apoptotic, p53, and NF-κB pathways and the activation of Nrf2/HO-1 pathway to ameliorate Cu overload-induced nephrotoxicity in a mouse model. Our study highlights that curcumin supplementation may be a promising treatment strategy for treating copper overload-caused nephrotoxicity.

T-2 toxin and its cardiotoxicity: New insights on the molecular mechanisms and therapeutic implications.

T-2 toxin is one of the most toxic and common trichothecene mycotoxins, and can cause various cardiovascular diseases. In this review, we summarized the current knowledge-base and challenges as it relates to T-2 toxin related cardiotoxicity. The molecular mechanisms and potential treatment approaches were also discussed. Pathologically, T-2 toxin-induced cardiac toxicity is characterized by cell injury and death in cardiomyocyte, increased capillary permeability, necrosis of cardiomyocyte, hemorrhage, and the infiltration of inflammatory cells in the heart. T-2 toxin exposure can cause cardiac fibrosis and finally lead to cardiac dysfunction. Mechanistically, T-2 toxin exposure-induced cardiac damage involves the production of ROS, mitochondrial dysfunction, peroxisome proliferator-activated receptor-gamma (PPAR-γ) signaling pathway, endoplasmic reticulum (ER stress), transforming growth factor beta 1 (TGF-ß1)/smad family member 2/3 (Smad2/3) signaling pathway, and autophagy and inflammatory responses. Antioxidant supplementation (e.g., catalase, vitamin C, and selenium), induction of autophagy (e.g., rapamycin), blockade of inflammatory signaling (e.g., methylprednisolone) or treatment with PPAR-γ agonists (e.g., pioglitazone) may provide protective effects against these detrimental cardiac effects caused by T-2 toxin. We believe that our review provides new insights in understanding T-2 toxin exposure-induced cardiotoxicity and fuels effective prevention and treatment strategies against this important food-borne toxin-induced health problems.

Progress in Immunoassays of Toxic Alkaloids in Plant-Derived Medicines: A Review.

Plants are the cradle of the traditional medicine system, assuaging human or animal diseases, and promoting health for thousands of years. However, many plant-derived medicines contain toxic alkaloids of varying degrees of toxicity that pose a direct or indirect threat to human and animal health through accidental ingestion, misuse of plant materials, or through the food chain. Thus, rapid, easy, and sensitive methods are needed to effectively screen these toxic alkaloids to guarantee the safety of plant-derived medicines. Antibodies, due to their inherent specificity and high affinity, have been used as a variety of analytical tools and techniques. This review describes the antigen synthesis and antibody preparation of the common toxic alkaloids in plant-derived medicines and discusses the advances of antibody-based immunoassays in the screening and detection of toxic alkaloids in plants or other related matrices. Finally, the limitations and prospects of immunoassays for toxic alkaloids are discussed.

The joint effect of energy reduction with calcium supplementation on the risk factors of type 2 diabetes in the overweight population: a two-year randomized controlled trial.

Both excessive energy intake and low calcium intake are inversely associated with the aging-related diseases, particularly for type 2 diabetes mellitus(T2DM). This study examined whether energy reduction coupled with calcium supplementation aided in the prevention of T2DM among the overweight population. A randomized controlled trial(RCT) of 1021 overweight participants was performed, in which participants were randomly assigned to 4 groups: 1) energy-reduction group(ERG), 2) calcium supplementation group(CSG), 3) energy-reduction with calcium supplementation group(ER-CSG), 4) control group(CG). Nutritional habits, anthropometric and diabetes-related indicators were measured at baseline and each follow-up time. To analyze the separate effects of dietary energy reduction and calcium supplementation, ERG and ER-CSG were integrated into ERGs. Similarly, CSG and ER-CSG were integrated into CSGs. Compared to the non-energy-reduction groups(NERGs), ERGs had lower values of ΔBMI(-0.9kg/m2), ΔFSG (-0.34mmol/L), ΔHbA1c(0.16%), and ΔHOMA-IR(-0.13), and higher value of ΔGutt index(-5.82). Compared to the non-calcium supplementation groups(NCSGs), the ΔGutt index(-5.46) in CSGs showed a significant decrease. Moreover, these risk factors for T2DM were most effectively ameliorated in ER-CSG group with the decreased values of ΔFSG(-0.42mmol/L), ΔGutt index(-0.73), and the slowest increasing rate value of Δ2h-glucose(0.37mmol/L). This RCT demonstrated that energy-reduction with calcium supplementation was a useful dietary intervention strategy for preventing the development of T2DM in the overweight population.

Time-resolved fluorescent immunochromatographic assay-based on three antibody labels for the simultaneous detection of aflatoxin B1 and zearalenone in Chinese herbal medicines.

A time-resolved fluorescent immunochromatographic assay (TRFICA) was successfully developed for the sensitive, simultaneous, and quantitative detection of aflatoxin B1 (AFB1) and zearalenone (ZEN) in Chinese herbal medicines. Eu-nanospheres (EuNPs) with unique optical properties increased the stability and sensitivity of the immunochromatographic assay. To obtain stable quantitative results, we applied a three-label system in which monoclonal antibodies for AFB1 and ZEN were conjugated to the EuNPs as detection probes on the test line (T line), and EuNP-labelled chicken IgY conjugates acted as the reference on the control line (C line). The fluorescence intensities of the T and C lines were recorded, and the T/C ratio was employed as the quantitative signal for the elimination of strip variation and matrix effects. The parameters that affected the TRFICA were optimised. Under optimal conditions, the established TRFICA gave good linear ranges from 0.60 µg/kg to 3.92 µg/kg for AFB1 and from 0.40 µg/kg to 1.28 µg/kg for ZEN. The limits of detection for AFB1 and ZEN were as low as 0.60 and 0.40 µg/kg, respectively, in Chinese herbal medicines Semen coicis, Rhizoma dioscoreae, and Platycodon grandiflorus, respectively. The average recoveries of the spiked samples were 73%-95% for AFB1 and 75.83%-90% for ZEN, both with a relative standard deviation of < 9.08%. The results of 15 actual samples detected by the developed TRFICA showed a satisfactory correlation with those of ultra-performance liquid chromatography tandem mass spectrometry. Therefore, the TRFICA is a simple, rapid, and sensitive approach to quantitatively detect mycotoxins in Chinese herbal medicines.

Genome-wide analysis of maize CONSTANS-LIKE gene family and expression profiling under light/dark and abscisic acid treatment.

The CONSTANS-LIKE (COL) gene has an important role both in regulation flowering through photoperiodic control and response to abiotic stress. In the present study, we performed a genome-wide analysis of maize COL gene family and identified 19 non-redundant ZmCOL genes, which were unequally distributed on ten maize chromosomes. Analysis of compound phylogenetic tree (maize, sorghum, rice and Arabidopsis) showed high bootstrap, as well as conserved domain and semblable gene structures among members within the same clade, revealing that COL genes in same clade were from the common ancestral and prior to the divergence of monocots and dicots lineages. Calculation of Ka/Ks ratio demonstrated that most duplicated ZmCOLs experienced purifying selection, which suggested limited functional divergence after duplication events. Comparing interspecies gene collinearity between three major grasses species, extensive microsynteny was detected among maize, sorghum and rice COL-containing segments. Additionally, several light-responsive and one ABA-responsive cis-elements could be detected for ZmCOL genes in group A. Therefore, qRT-PCR was performed to explore the expression patterns of ZmCOL genes in group A under light/dark conditions and ABA treatment. Our results laid the foundation for functional characterization of ZmCOL proteins and uncovering the biological roles of COL genes in response to stress in future.

Determination of aflatoxin and zearalenone analogs in edible and medicinal herbs using a group-specific immunoaffinity column coupled to ultra-high-performance liquid chromatography with tandem mass spectrometry.

Six aflatoxins (AFs; AF B1, B2, G1, G2, M1 and M2) and six zearalenone (ZEN) analogs (ZEN, zearalanone, α-zeralanol, ß-zeralanol, α-zearalenol, and ß-zearalenol) were simultaneously extracted from edible and medicinal herbs using a group-specific immunoaffinity column (IAC) and then identified by ultra-high-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). The IAC was prepared by coupling N-hydroxysuccinimide-activated Sepharose 4B Fast Flow gel with two group-specific monoclonal antibodies. The column capacities to six AFs and six ZEN analogs ranged from 100.2 ng to 167.1 ng and from 59.5 ng to 244.4 ng, respectively. The IAC-UPLC-MS/MS method was developed and validated with three different matrices (Chinese yam [Dioscorea polystachya], Platycodon grandiflorum and coix seed [Semen Coicis]). Recoveries of twelve analytes from edible and medicinal herbs were in the range of 64.7%-112.1%, with relative standard deviations below 13.7%. The limits of quantification were in the range from 0.08 µg kg-1 to 0.2 µg kg-1. The method was proven to be sensitive and accurate, and suitable for the determination of real samples.

SDG721 and SDG705 are required for rice growth.

H3K4me3 plays important roles in development, transcription, and environmental responses. Here, we report that SDG721 (SET-domain group protein 721) and SDG705 are involved in regulating rice development. SDG721 and SDG705 encode TRITHORAX-like proteins, which appear to modulate H3K4 methylation levels. Loss of SDG721 and SDG705 function resulted in GA-deficient phenotypes, including semi-dwarfism, reduced cell length, and reduced panicle branching. The transcripts levels and H3K4me3 levels of GA biosynthesis genes and GA signaling pathway genes were downregulated in the sdg721 sdg705 plants. Together, these results suggest that SDG721 and SDG705 regulate H3K4 methylation, which is crucial for plant development in rice.

Opsin 3 and 4 mediate light-induced pulmonary vasorelaxation that is potentiated by G protein-coupled receptor kinase 2 inhibition.

We recently demonstrated that blue light induces vasorelaxation in the systemic mouse circulation, a phenomenon mediated by the nonvisual G protein-coupled receptor melanopsin (Opsin 4; Opn4). Here we tested the hypothesis that nonvisual opsins mediate photorelaxation in the pulmonary circulation. We discovered Opsin 3 (Opn3), Opn4, and G protein-coupled receptor kinase 2 (GRK2) in rat pulmonary arteries (PAs) and in pulmonary arterial smooth muscle cells (PASMCs), where the opsins interact directly with GRK2, as demonstrated with a proximity ligation assay. Light elicited an intensity-dependent relaxation of PAs preconstricted with phenylephrine (PE), with a maximum response between 400 and 460 nm (blue light). Wavelength-specific photorelaxation was attenuated in PAs from Opn4-/- mice and further reduced following shRNA-mediated knockdown of Opn3. Inhibition of GRK2 amplified the response and prevented physiological desensitization to repeated light exposure. Blue light also prevented PE-induced constriction in isolated PAs, decreased basal tone, ablated PE-induced single-cell contraction of PASMCs, and reversed PE-induced depolarization in PASMCs when GRK2 was inhibited. The photorelaxation response was modulated by soluble guanylyl cyclase but not by protein kinase G or nitric oxide. Most importantly, blue light induced significant vasorelaxation of PAs from rats with chronic pulmonary hypertension and effectively lowered pulmonary arterial pressure in isolated intact perfused rat lungs subjected to acute hypoxia. These findings show that functional Opn3 and Opn4 in PAs represent an endogenous "optogenetic system" that mediates photorelaxation in the pulmonary vasculature. Phototherapy in conjunction with GRK2 inhibition could therefore provide an alternative treatment strategy for pulmonary vasoconstrictive disorders.

Broad-spectrum immunoaffinity cleanup for the determination of aflatoxins B1, B2, G1, G2, M1, M2 in Ophiocordyceps sinensis and its pharmaceutical preparations by ultra performance liquid chromatography tandem mass spectrometry.

An ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method was developed and validated for the simultaneous determination of aflatoxins B1, B2, G1, G2, M1 and M2 (AFB1, AFB2, AFG1, AFG2, AFM1 and AFM2) in Ophiocordyceps sinensis and its pharmaceutical preparations. A rapid and reliable immunoaffinity column containing a broad-spectrum monoclonal antibody for six aflatoxins was used for sample cleanup. Under the optimized conditions, the home-made immunoaffinity column capacity were about 315, 319, 292, 102, 444 and 369ng/mL gel for AFB1, AFB2, AFG1, AFG2, AFM1 and AFM2, respectively. Recoveries for all tested aflatoxins ranged from 79.28% to 103.42% with relative standard deviation less than 8%. The limits of quantitation were in the range of 0.008-0.045µg/kg. Among 31 real samples analyzed, one sample was contaminated with AFB1, AFB2 and AFM1 at levels of 0.483, 0.068 and 0.104µg/kg, respectively. The established method is simple, accurate, and can be effectively used to determine the aflatoxins in Ophiocordyceps sinensis and its pharmaceutical preparations.

Tanshinone IIA enhances bystander cell killing of cancer cells expressing Drosophila melanogaster deoxyribonucleoside kinase in nuclei and mitochondria.

Heterologous expression of the Drosophila melanogaster multi-substrate deoxyribonucleoside kinase (Dm-dNK) increases the sensitivity of cancer cells to several cytotoxic nucleoside analogs. Thus, it may be used as a suicide gene in combined gene/chemotherapy treatment of cancer. To further characterize this potential suicide gene, we constructed two retroviral vectors that enabled the expression of Dm-dNK in cancer cells. One vector harbored the wild­type enzyme that localized to the nucleus. The other vector harbored a mitochondrial localized mutant enzyme that was constructed by deleting the nuclear localization signal and fusing it to a mitochondrial import signal of cytochrome c oxidase. A thymidine kinase-deficient osteosarcoma cell line was transduced with the recombinant viruses. The sensitivity and bystander cell killing in the presence of pyrimidine nucleoside analogs (E)-5-(2-bromovinyl)­2'­deoxyuridine and 1-ß-D-arabinofuranosylthymine were investigated. Tanshinone IIA is a constituent of Danshen; a traditional Chinese medicine used in the treatment of cardiovascular diseases. This study also looked at the influence of Tanshinone IIA on the bystander effect and the underlying mechanisms. We showed that sensitivity of the osteosarcoma cell line to the nucleoside analogs and the efficiency of bystander cell killing were independent of the subcellular localization of Dm-dNK. The enhanced effect of tanshinone IIA on the bystander effect was related to the increased expression of Cx43 and Cx26.

Nicotinamide forestalls pathology and cognitive decline in Alzheimer mice: evidence for improved neuronal bioenergetics and autophagy procession.

Impaired brain energy metabolism and oxidative stress are implicated in cognitive decline and the pathologic accumulations of amyloid ß-peptide (Aß) and hyperphosphorylated tau in Alzheimer's disease (AD). To determine whether improving brain energy metabolism will forestall disease progress in AD, the impact of the ß-nicotinamide adenine dinucleotide precursor nicotinamide on brain cell mitochondrial function and macroautophagy, bioenergetics-related signaling, and cognitive performance were studied in cultured neurons and in a mouse model of AD. Oxidative stress resulted in decreased mitochondrial mass, mitochondrial degeneration, and autophagosome accumulation in neurons. Nicotinamide preserved mitochondrial integrity and autophagy function, and reduced neuronal vulnerability to oxidative/metabolic insults and Aß toxicity. ß-Nicotinamide adenine dinucleotide biosynthesis, autophagy, and phosphatidylinositol-3-kinase signaling were required for the neuroprotective action of nicotinamide. Treatment of 3xTgAD mice with nicotinamide for 8 months resulted in improved cognitive performance, and reduced Aß and hyperphosphorylated tau pathologies in hippocampus and cerebral cortex. Nicotinamide treatment preserved mitochondrial integrity, and improved autophagy-lysosome procession by enhancing lysosome/autolysosome acidification to reduce autophagosome accumulation. Treatment of 3xTgAD mice with nicotinamide resulted in elevated levels of activated neuroplasticity-related kinases (protein kinase B [Akt] and extracellular signal-regulated kinases) and the transcription factor cyclic adenosine monophosphate (AMP) response element-binding protein in the hippocampus and cerebral cortex. Thus, nicotinamide suppresses AD pathology and cognitive decline in a mouse model of AD by a mechanism involving improved brain bioenergetics with preserved functionality of mitochondria and the autophagy system.

Reactivation of a silenced minimal Mutator transposable element system following low-energy nitrogen ion implantation in maize.

In maize, Mutator transposable elements are either active or silenced within the genome. In response to environmental stress, silenced Mutator elements could be reactivated, leading to changes in genome structure and gene function. However, there is no direct experimental evidence linking environmental stress and Mutator transposon reactivation. Using a maize line that contains a single inactive MuDR and a lone nonautonomous Mutator element, a Mu1 insertion in the recessive reporter allele a1-mum2 in an inactive Mutator background, we directly assessed Mutator reactivation following low-energy nitrogen ion implantation. We observed that N(+) implantation decreased cytosine methylation in MuDR terminal inverted repeats and increased expression of mudrA and mudrB. Both changes were associated with increased transpositional activity of MuDR through reactivation of the inactive minimal Mutator transposable element system. This study provides direct evidence linking environmental stress agents and Mutator transposon mobilization in maize. In addition, the observed changes to DNA methylation suggest a new mechanism for mutations by low-energy ion implantation.