Traditional Korean diet high in one-carbon nutrients increases global DNA methylation: implication for epigenetic diet.

PURPOSE: DNA methylation is a major epigenetic phenomenon through which diet affects health and disease. This study aimed to determine the epigenetic influence of the traditional Korean diet (K-diet) on global DNA methylation via one-carbon metabolism. METHODS: A crossover study was conducted on 52 women. Two diets, a K-diet, high in plant foods and low in calories and animal fat, and a control diet, similar to the diet currently consumed in Korea, were provided to all subjects alternately for 4 weeks with a 4-week washout period. Clinical parameters were measured before and after each dietary intervention. Nutrient intake was calculated by using a computer-aided nutritional analysis program. One-carbon metabolites in the serum and global DNA methylation in peripheral mononuclear cells were determined using ultra-performance liquid chromatography-tandem mass spectrometry. RESULTS: The K-diet group consumed more folate (669.9 ± 6.7 µg vs. 502.7 ± 3.0, p < 0.001), B6, B12, serine, and choline, and less methionine (992.6 ± 63 vs. 1048.3 mg ± 34.1, p < 0.0001) than the control group did. In the K-diet group, the increment of plasma 5-methyltetrahydrofolate (0.08 µg/mL ± 0.11 vs 0.02 ± 0.10, p < 0.009) and decrement of L-homocysteine (- 70.7 ± 85.0 vs - 39.3 ± 69.4, p < 0.0168) were greater than those of the control group. Global DNA methylation was significantly increased in the K-diet group (6.70 ± 3.02% to 9.45 ± 3.69, p < 0.0001) but not in the control group. CONCLUSIONS: A K-diet high in one-carbon nutrients can enhance the global DNA methylation status, suggesting an epigenetic mechanism by which the K-diet conveys health effects. Trial registration Korean Clinical Trial Registry (trial number: KCT0005340, 24/08/2020, retrospectively registered).

An Update on the Chemical Constituents and Biological Properties of Selected Species of an Underpinned Genus of Red Algae: Chondrus.

Macroalgae, particularly red seaweeds, have attracted significant attention due to their economic and health benefits. Chondrus, a red algae genus, despite its economic importance, seems to be undervalued. Among all its species, Chondrus crispus has been meticulously documented for its biological properties, and little is known about other species. No comprehensive review of the biological properties of this genus has been acknowledged. Thus, this review aimed to summarize the available information on the chemical constituents and biological properties of a few selected species, including Chondrus crispus, Chondrus ocellatus, Mazzaella canaliculata, and Chondrus armatus. We compiled and discovered that the genus is offering most of the important health-promoting benefits evidenced from in vitro and in vivo studies focused on antimicrobial, immunomodulation, neuroprotection, anti-atopic, anti-inflammatory, anti-viral, anti-diabetic, cytoprotective, antioxidant, anti-coagulation, nephroprotective, anti-tumor, and anti-venom activity, which speaks about the potential of this genus. Data on clinical studies are limited. Further, around 105 chemical constituents have been reported from Chondrus spp. Given its significance, further investigation is warranted, in the form of meticulously planned cell, animal, and clinical studies that concentrate on novel health-enhancing endeavors, in order to unveil the full potential of this genus. The review also outlines challenges and future directions.

Flower morphology as a predictor of pollination mode in a biotic to abiotic pollination continuum.

BACKGROUND AND AIMS: Wind pollination has evolved repeatedly in flowering plants, yet the identification of a wind pollination syndrome as a set of integrated floral traits can be elusive. Thalictrum (Ranunculaceae) comprises temperate perennial herbs that have transitioned repeatedly from insect to wind pollination while also exhibiting mixed pollination, providing an ideal system to test for evolutionary correlation between floral morphology and pollination mode in a biotic to abiotic continuum. Moreover, the lack of floral organ fusion across this genus allows testing for specialization to pollination vectors in the absence of this feature. METHODS: We expanded phylogenetic sampling in the genus from a previous study using six chloroplast loci, which allowed us to test whether species cluster into distinct pollination syndromes based on floral morphology. We then used multivariate analyses on floral traits followed by ancestral state reconstruction of the emerging flower morphotypes and determined whether these traits are evolutionarily correlated under a Bayesian framework with Brownian motion. KEY RESULTS: Floral traits fell into five distinct clusters, which were reduced to three after considering phylogenetic relatedness and were largely consistent with flower morphotypes and associated pollination vectors. Multivariate evolutionary analyses found a positive correlation between the lengths of floral reproductive structures (styles, stigmas, filaments and anthers). Shorter reproductive structures tracked insect-pollinated species and clades in the phylogeny, whereas longer structures tracked wind-pollinated ones, consistent with selective pressures exerted by biotic vs. abiotic pollination vectors, respectively. CONCLUSIONS: Although detectable suites of integrated floral traits across Thalictrum were correlated with wind or insect pollination at the extremes of the morphospace distribution, a presumed intermediate, mixed pollination mode morphospace was also detected. Thus, our data broadly support the existence of detectable flower morphotypes from convergent evolution underlying the evolution of pollination mode in Thalictrum, presumably via different paths from an ancestral mixed pollination state.

Postbiotics against Obesity: Perception and Overview Based on Pre-Clinical and Clinical Studies.

Overweight and obesity are significant global public health concerns that are increasing in prevalence at an alarming rate. Numerous studies have demonstrated the benefits of probiotics against obesity. Postbiotics are the next generation of probiotics that include bacteria-free extracts and nonviable microorganisms that may be advantageous to the host and are being increasingly preferred over regular probiotics. However, the impact of postbiotics on obesity has not been thoroughly investigated. Therefore, the goal of this review is to gather in-depth data on the ability of postbiotics to combat obesity. Postbiotics have been reported to have significant potential in alleviating obesity. This review comprehensively discusses the anti-obesity effects of postbiotics in cellular, animal, and clinical studies. Postbiotics exert anti-obesity effects via multiple mechanisms, with the major mechanisms including increased energy expenditure, reduced adipogenesis and adipocyte differentiation, suppression of food intake, inhibition of lipid absorption, regulation of lipid metabolism, and regulation of gut dysbiosis. Future research should include further in-depth studies on strain identification, scale-up of postbiotics, identification of underlying mechanisms, and well-defined clinical studies. Postbiotics could be a promising dietary intervention for the prevention and management of obesity.

Cellular toxicity profile of a new ophthalmic sponge.

Introduction: Ophthalmic sponges are used for cleaning the eye surface and absorbing fluids during ophthalmic procedures. This study compared the biological safety and stability of a new ophthalmic sponge, Occucell® (OccuTech Inc, Seongnam, Korea), on the human conjunctival epithelial cells with those of preexisting products to evaluate its clinical application.Materials and Methods: The cytotoxicity of four products, Occucell, a new product, Ultracell®, Eyetec-1, and Eyetec-2, on conjunctival epithelial cells, was evaluated using the MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) analysis. Additionally, human conjunctival epithelial cells were stained with a Live & Dead marker and observed using a fluorescence microscope. To evaluate the effect of the ophthalmic sponges on the secretion of IL-1ß and TNF-α, cultured conjunctival epithelial cells were treated with 0.5% DMSO eluates of the ophthalmic sponges, and IL-1ß and TNF-α mRNA levels were estimated using real-time polymerase chain reaction assays.Results: Cells treated with Occucell showed comparable viability to those treated with other preexisting products. Conjunctival epithelial cells showed more than 90% viability when treated with the ophthalmic sponge extracts, as determined by the MTT assay. No significant differences in the number of live & dead cells were observed between the control and treatment groups. Cells treated with all four ophthalmic sponge eluates showed similar IL-1ß and TNF-α mRNA levels.Discussion: Occucell, an eye sponge used during ophthalmic surgery in clinical practice, did not affect the viability of conjunctival epithelial cells, and more than 90% of the cells were viable after the treatment. Further, Occucell showed similar effects on IL-1ß and TNF-α secretion as that of other ophthalmic sponges used in the clinic. This suggested that Occucell is a safe product comparable to the preexisting products.

Transcriptome-Wide Identification and Quantification of Caffeoylquinic Acid Biosynthesis Pathway and Prediction of Its Putative BAHDs Gene Complex in A. spathulifolius.

The phenylpropanoid pathway is a major secondary metabolite pathway that helps plants overcome biotic and abiotic stress and produces various byproducts that promote human health. Its byproduct caffeoylquinic acid is a soluble phenolic compound present in many angiosperms. Hydroxycinnamate-CoA shikimate/quinate transferase is a significant enzyme that plays a role in accumulating CQA biosynthesis. This study analyzed transcriptome-wide identification of the phenylpropanoid to caffeoylquinic acid biosynthesis candidate genes in A. spathulifolius flowers and leaves. Transcriptomic analyses of the flowers and leaves showed a differential expression of the PPP and CQA biosynthesis regulated unigenes. An analysis of PPP-captive unigenes revealed a major duplication in the following genes: PAL, 120 unigenes in leaves and 76 in flowers; C3'H, 169 unigenes in leaves and 140 in flowers; 4CL, 41 unigenes in leaves and 27 in flowers; and C4H, 12 unigenes in leaves and 4 in flowers. The phylogenetic analysis revealed 82 BAHDs superfamily members in leaves and 72 in flowers, among which five unigenes encode for HQT and three for HCT. The three HQT are common to both leaves and flowers, whereas the two HQT were specialized for leaves. The pattern of HQT synthesis was upregulated in flowers, whereas HCT was expressed strongly in the leaves of A. spathulifolius. Overall, 4CL, C4H, and HQT are expressed strongly in flowers and CAA and HCT show more expression in leaves. As a result, the quantification of HQT and HCT indicates that CQA biosynthesis is more abundant in the flowers and synthesis of caffeic acid in the leaves of A. spathulifolius.

Karyopherin α-2 Mediates MDC1 Nuclear Import through a Functional Nuclear Localization Signal in the tBRCT Domain of MDC1.

Mediator of DNA damage checkpoint protein 1 (MDC1) plays a vital role in DNA damage response (DDR) by coordinating the repair of double strand breaks (DSBs). Here, we identified a novel interaction between MDC1 and karyopherin α-2 (KPNA2), a nucleocytoplasmic transport adaptor, and showed that KPNA2 is necessary for MDC1 nuclear import. Thereafter, we identified a functional nuclear localization signal (NLS) between amino acid residues 1989-1994 of the two Breast Cancer 1 (BRCA1) carboxyl-terminal (tBRCT) domain of MDC1 and demonstrated disruption of this NLS impaired interaction between MDC1 and KPNA2 and reduced nuclear localization of MDC1. In KPNA2-depleted cells, the recruitment of MDC1, along with the downstream signaling p roteins Ring Finger Protein 8 (RNF8), 53BP1-binding protein 1 (53BP1), BRCA1, and Ring Finger Protein 168 (RNF168), to DNA damage sites was abolished. Additionally, KPNA2-depleted cells had a decreased rate of homologous recombination (HR) repair. Our data suggest that KPNA2-mediated MDC1 nuclear import is important for DDR signaling and DSB repair.

Oncogenic Ras downregulates mdr1b expression through generation of reactive oxygen species.

In the present study, we investigated the effect of oncogenic H-Ras on rat mdr1b expression in NIH3T3 cells. The constitutive expression of H-RasV12 was found to downregulate the mdr1b promoter activity and mdr1b mRNA expression. The doxorubicin-induced mdr1b promoter activity of the H-RasV12 expressing NIH3T3 cells was markedly lower than that of control NIH3T3 cells. Additionally, there is a positive correlation between the level of H-RasV12 expression and a sensitivity to doxorubicin toxicity. To examine the detailed mechanism of H-RasV12-mediated down-regulation of mdr1b expression, antioxidant N-acetylcysteine (NAC) and NADPH oxidase inhibitor diphenylene iodonium (DPI) were used. Pretreating cells with either NAC or DPI significantly enhanced the oncogenic H-Ras-mediated down-regulation of mdr1b expression and markedly prevented doxorubicin-induced cell death. Moreover, NAC and DPI treatment led to a decrease in ERK activity, and the ERK inhibitors PD98059 or U0126 enhanced the mdr1b-Luc activity of H-RasV12-NIH3T3 and reduced doxorubicin-induced apoptosis. These data suggest that RasV12 expression could downregulate mdr1b expression through intracellular reactive oxygen species (ROS) production, and ERK activation induced by ROS, is at least in part, contributed to the downregulation of mdr1b expression.

p53R2 regulates thioredoxin reductase activity through interaction with TrxR2.

Ribonucleotide reductase small subunit p53R2 is a member of the ribonucleotide reductase family that supplies dNTPs for nuclear and mitochondrial DNA replication and repair. Here, we have identified a mitochondrial thioredoxin reductase 2 (TrxR2) as a novel p53R2-binding protein. We demonstrated a direct interaction between the two, and observed that p53R2 stimulated the enzymatic activity of TrxR in vitro. Moreover, TrxR2 activity was significantly lower in p53R2 knockdown cells, and increased when p53R2 was overexpressed, effects that were independent of p53. Furthermore, p53R2 knockdown suppressed UV-induced TrxR activity. These findings suggest that p53R2 acts as a positive regulator of TrxR2 activity in mitochondria both under normal physiological conditions and during the cellular response to DNA damage.

The oncogenic effects of p53-inducible gene 3 (PIG3) in colon cancer cells.

The p53-inducible gene 3 (PIG3), initially identified as a gene downstream of p53, plays an important role in the apoptotic process triggered by p53-mediated reactive oxygen species (ROS) production. Recently, several studies have suggested that PIG3 may play a role in various types of cancer. However, the functional significance of PIG3 in cancer remains unclear. Here, we found that PIG3 was highly expressed in human colon cancer cell lines compared to normal colonderived fibroblasts. Therefore, we attempted to elucidate the functional role of PIG3 in colon cancer. PIG3 overexpression increases the colony formation, migration and invasion ability of HCT116 colon cancer cells. Conversely, these tumorigenic abilities were significantly decreased in in vitro studies with PIG3 knockdown HCT116 cells. PIG3 knockdown also attenuated the growth of mouse xenograft tumors. These results demonstrate that PIG3 is associated with the tumorigenic potential of cancer cells, both in vitro and in vivo, and could play a key oncogenic role in colon cancer.

An Ultrasensitive, Selective, Multiplexed Superbioelectronic Nose That Mimics the Human Sense of Smell.

Human sensory-mimicking systems, such as electronic brains, tongues, skin, and ears, have been promoted for use in improving social welfare. However, no significant achievements have been made in mimicking the human nose due to the complexity of olfactory sensory neurons. Combinational coding of human olfactory receptors (hORs) is essential for odorant discrimination in mixtures, and the development of hOR-combined multiplexed systems has progressed slowly. Here, we report the first demonstration of an artificial multiplexed superbioelectronic nose (MSB-nose) that mimics the human olfactory sensory system, leading to high-performance odorant discriminatory ability in mixtures. Specifically, portable MSB-noses were constructed using highly uniform graphene micropatterns (GMs) that were conjugated with two different hORs, which were employed as transducers in a liquid-ion gated field-effect transistor (FET). Field-induced signals from the MSB-nose were monitored and provided high sensitivity and selectivity toward target odorants (minimum detectable level: 0.1 fM). More importantly, the potential of the MSB-nose as a tool to encode hOR combinations was demonstrated using principal component analysis.

Plasma isoflavone concentration is associated with decreased risk of type 2 diabetes in Korean women but not men: results from the Korean Genome and Epidemiology Study.

AIMS/HYPOTHESIS: To examine the association between soybean products and risk of type 2 diabetes, we measured four isoflavone biological markers--genistein, daidzein, glycitein and equol--in a nested case-control study. METHODS: The study population was composed of 693 cases (316 women and 377 men) and 698 matched controls (317 women and 381 men) within the Korean Genome and Epidemiology Study. The concentrations of isoflavone biomarkers were measured using HPLC-MS/MS on plasma samples that were collected at baseline. A stratified analysis was undertaken to examine the association between plasma isoflavone concentrations and risk of type 2 diabetes according to sex and equol production. Logistic regression models were used to compute ORs and 95% CIs adjusted for confounders. RESULTS: In women, compared with the lowest quartile of plasma concentration of genistein, the highest quartile exhibited a significantly decreased risk of diabetes (OR 0.58, 95% CI 0.35, 0.95). When stratified by equol-producing status in women, the OR for diabetes in the highest vs the lowest quartile of genistein concentration was 0.31 (95% CI 0.16, 0.60) in equol producers, but genistein concentration was not associated with risk of diabetes in equol non-producers (p for interaction = 0.013). In men, isoflavone concentrations were not associated with risk of diabetes, regardless of equol-producing status. CONCLUSIONS/INTERPRETATION: High plasma concentrations of genistein were associated with a decreased risk of type 2 diabetes in women. This inverse association was prominent in equol-producing participants. These results suggest a beneficial effect of a high intake of soybean products on risk of type 2 diabetes in women.

Polypyrrole nanotube embedded reduced graphene oxide transducer for field-effect transistor-type H2O2 biosensor.

We report a rapid-response and high-sensitivity sensor with specificity toward H2O2 based on a liquid-ion-gated field-effect transistor (FET) using graphene-polypyrrole (PPy) nanotube (NT) composites as the conductive channel. The rGO, PPy, NTs, and nanocomposite materials were characterized using Raman spectroscopy, Fourier transform-infrared (FT-IR) spectroscopy, transmission electron microscopy (TEM), and scanning electron microscopy (SEM). On the basis of these results, a well-organized structure is successfully prepared owing to the specific interactions between the PPy NTs and the rGO sheet. Reliable electrical contacts were developed between the rGO/PPy NTs and the microelectrodes, which remained stable when exposed to the liquid-phase analyte. Liquid-ion-gated FETs composed of these graphene nanocomposites exhibited hole-transport behavior with conductivities higher than those of rGO sheets or PPy NTs. This implies an interaction between the PPy NTs and the rGO layers, which is explained in terms of the PPy NTs forming a bridge between the rGO layers. The FET sensor provided a rapid response in real time and high sensitivity toward H2O2 with a limit of detection of 100 pM. The FET-type biosensing geometry was also highly reproducible and stable in air. Furthermore, the liquid-gated FET-type sensor exhibited specificity toward H2O2 in a mixed solution containing compounds found in biological fluids.

High-performance Hg(2+) FET-type sensors based on reduced graphene oxide-polyfuran nanohybrids.

A new type of field-effect transistor (FET) sensor, based on reduced graphene oxide (rGO)-polyfuran (PF) nanohybrids, was strategically developed. The sensing transducer exhibited a rapid response (<1 s) and high sensitivity (10 pM) in a liquid-ion-gated FET-type Hg(2+) sensor. Excellent Hg(2+) discrimination in heavy metal mixtures was also monitored in real time.

Conducting polymer-based nanohybrid transducers: a potential route to high sensitivity and selectivity sensors.

The development of novel sensing materials provides good opportunities to realize previously unachievable sensor performance. In this review, conducting polymer-based nanohybrids are highlighted as innovative transducers for high-performance chemical and biological sensing devices. Synthetic strategies of the nanohybrids are categorized into four groups: (1) impregnation, followed by reduction; (2) concurrent redox reactions; (3) electrochemical deposition; (4) seeding approach. Nanocale hybridization of conducting polymers with inorganic components can lead to improved sorption, catalytic reaction and/or transport behavior of the material systems. The nanohybrids have thus been used to detect nerve agents, toxic gases, volatile organic compounds, glucose, dopamine, and DNA. Given further advances in nanohybrids synthesis, it is expected that sensor technology will also evolve, especially in terms of sensitivity and selectivity.

Human taste receptor-functionalized field effect transistor as a human-like nanobioelectronic tongue.

In this study, we developed a human taste receptor protein, hTAS2R38-functionalized carboxylated polypyrrole nanotube (CPNT)-field effect transistor (FET) as a nanobioelectronic tongue (nbe-tongue) that displayed human-like performance with high sensitivity and selectivity. Taster type (PAV) and nontaster type (AVI) hTAS2R38s were expressed in Escherichia coli (E. coli) at a high level and immobilized on a CPNT-FET sensor platform. Among the various tastants examined, PAV-CPNT-FET exclusively responded to target bitterness compounds, phenylthiocarbamide (PTC) and propylthiouracil (PROP), with high sensitivity at concentrations as low as 1 fM. However, no significant changes were observed in the AVI-CPNT-FET in response to the target bitter tastants. This nbe-tongue exhibited different bitter-taste perception of compounds containing thiourea (N-C═S) moieties such as PTC, PROP, and antithyroid toxin in vegetables, which corresponded to the haplotype of hTAS2R38 immobilized on CPNTs. This correlation with the type of receptor is very similar to the human taste system. Thus, the artificial taste sensor developed in this study allowed for the efficient detection of target tastants in mixture and real food sample with a human-like performance and high sensitivity. Furthermore, our nbe-tongue could be utilized as a substitute for cell-based assays and to better understand the mechanisms of human taste.

Healthy and Unhealthy Dietary Patterns of Depressive Symptoms in Middle-Aged Women.

Depressive symptoms are a common menopausal feature in middle-aged women and are associated with dietary factors. This study aimed to determine the association between dietary patterns and depressive symptoms in 2190 Korean women aged 45-69 years. Depressive symptoms were screened using the Beck Depression Inventory-II (BDI-II), and food intake was examined using a food frequency questionnaire. Dietary patterns were derived from principal components analysis and identified two dietary patterns: a "healthy" dietary pattern (high intake of whole-grain rice, legumes, vegetables, fruits, and fish) and an "unhealthy" dietary pattern (high intake of noodles, dumplings, sweets, red meat, soda, and coffee). After adjusting for all confounding factors, those with the highest healthy dietary pattern scores had a 0.56-fold lower risk of depressive symptoms than those with the lowest score (Odds Ratio (OR) = 0.56, 95% confidence interval (CI): 0.37-0.84, p for trend = 0.006). Conversely, those with the highest unhealthy pattern scores had a 1.85-fold higher risk of depressive symptoms than that of those in the lowest quartile (OR = 1.85, 95% CI: 1.30-2.63, p for trend = 0.002). In middle-aged women, a dietary pattern of high intake of fiber-rich whole-grain rice, fruits, vegetables, and legumes may help prevent and manage depressive symptoms.

Nutrition survey methods and food composition database update of the Korean Genome and Epidemiology Study.

This study presents the nutrition survey methods and the updated food composition database for the Korean Genome and Epidemiology Study (KoGES). The KoGES, which is the largest and longest cohort study in Korea, aims to identify genetic and environmental factors associated with chronic diseases. This study has collected dietary data using a validated semi-quantitative food frequency questionnaire and/or the 24-hour recall method. However, these dietary survey methods use different food composition databases, and their nutritional values are out of date. Therefore, it became necessary to update the food composition database by revising nutrient analysis values to reflect improvements in the performance of food ingredient analysis equipment, revising international values to analysis values of Korean agricultural products, adjusting nutrient units, and adding newly reported nutrients related to chronic diseases. For this purpose, we integrated the different food composition databases used in each nutrition survey, updated 23 nutrients, and expanded 48 new nutrients for 3,648 food items using the latest reliable food composition databases published by national and international institutions. This revised food composition database may help to clarify the relationship between various nutrients and chronic diseases. It could serve as a valuable resource for nutritional, epidemiological, and genomic research and provide a basis for determining public health policies.

A role of DNA-dependent protein kinase for the activation of AMP-activated protein kinase in response to glucose deprivation.

The catalytic subunit of DNA-dependent protein kinase (DNA-PKcs) plays an essential role in double-strand break repair by initially recognizing and binding to DNA breaks. Here, we show that DNA-PKcs interacts with the regulatory γ1 subunit of AMP-activated protein kinase (AMPK), a heterotrimeric enzyme that has been proposed to function as a "fuel gauge" to monitor changes in the energy status of cells and is controlled by the upstream kinases LKB1 and Ca²âº/calmodulin-dependent kinase kinase (CaMKK). In co-immunoprecipitation analyses, DNA-PKcs and AMPKγ1 interacted physically in DNA-PKcs-proficient M059K cells but not in DNA-PKcs-deficient M059J cells. Glucose deprivation-stimulated phosphorylation of AMPKα on Thr172 and of acetyl-CoA carboxylase (ACC), a downstream target of AMPK, is substantially reduced in M059J cells compared with M059K cells. The inhibition or down-regulation of DNA-PKcs by the DNA-PKcs inhibitors, wortmannin and Nu7441, or by DNA-PKcs siRNA caused a marked reduction in AMPK phosphorylation, AMPK activity, and ACC phosphorylation in response to glucose depletion in M059K, WI38, and IMR90 cells. In addition, DNA-DNA-PKcs(-/-) mouse embryonic fibroblasts (MEFs) exhibited decreased AMPK activation in response to glucose-free conditions. Furthermore, the knockdown of DNA-PKcs led to the suppression of AMPK (Thr172) phosphorylation in LKB1-deficient HeLa cells under glucose deprivation. Taken together, these findings support the positive regulation of AMPK activation by DNA-PKcs under glucose-deprived conditions in mammalian cells.

Fabrication of graphene sheets intercalated with manganese oxide/carbon nanofibers: toward high-capacity energy storage.

Herein, 3D nanohybrid architectures consisting of MnO(x) nanocrystals, carbon nanofibers (CNFs), and graphene sheets are fabricated. MnO(x) -decorated CNFs (MCNFs) with diameters of about 50 nm are readily obtained via single-nozzle co-electrospinning, followed by heat treatment. The MCNFs are then intercalated between graphene sheets, yielding the ternary nanohybrid MCNF/reduced graphene oxide (RGO). This straightforward synthesis process readily affords product on a scale of tens of grams. The ultrathin CNFs, which might be a promising alternative to carbon nanotubes (CNTs), overcome the low electrical conductivity of the excellent pseudocapacitive component, MnO(x) . Furthermore, the graphene sheets separated by the MCNFs boost the electrochemical performance of the nanohybrid electrodes. These nanohybrid electrodes exhibit enhanced specific capacitances compared with a sheet electrode fabricated of MCNF-only or RGO-only. Evidently, the RGO sheet acts as a conductive channel inside the nanohybrid, while the intercalated MCNFs increase the efficiency of the ion and charge transfer in the nanohybrid. The proposed nanohybrid architectures are expected to lay the foundation for the design and fabrication of high-performance electrodes.