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This article provides an overview of the role of DNA methylation in cancer, focusing on its functions, therapy implications, and potential future developments. Abnormal DNA methylation is commonly observed in cancer and is considered an important indicator of malignant progression. The article discusses the role of DNA methyltransferases (DNMTs) in both hematologic malignancies and solid tumors. It also highlights the potential for targeted therapy by inhibiting DNA methylation. The article emphasizes the importance of identifying key methylation changes in different types of cancer through pan-cancer analyses to identify relevant molecular targets. Additionally, it explores the potential of combining DNA methylation targeting with immune therapy for future tumor treatment development. However, the article acknowledges limitations in current research, such as the focus on DNA methylation in promoter regions and the need for comprehensive multi-omics analyses. Overall, the article underscores the significance of DNA methylation in cancer and the potential for personalized clinical treatments. [Extracted from the article]

Objective • To study the effectiveness and value of evidencebased nursing and predictive nursing in emergency treatment of upper gastrointestinal bleeding. Methods • A total of 100 patients with upper gastrointestinal bleeding in our hospital were selected. The period was from January 2020 to June 2022. They were grouped according to the double color ball method, 50 cases in the control group were given routine nursing, and 50 cases in the observation group were given evidence-based nursing combined with predictive nursing. The key points of evidence-based nursing are to identify the evidence-based question, search for relevant literature, identify scientifically effective nursing measures, and develop nursing care plans that are tailored to the patient’s specific situation based on evidence and clinical experience. Predictive nursing requires nurses to have a high level of awareness and risk prevention consciousness to provide care for early signs of bleeding and prevent the occurrence of complications. The psychological state scores, clinical-related indicators, clinical efficacy, incidence of complications, nursing satisfaction, and quality of life scores of the two groups were compared. Results • After the intervention, the SAS score (42.25 ± 1.67) and SDS score (43.59 ± 1.86) of the observation group were lower than those of the control group, the bleeding times (2.41 ± 0.45) of the observation group were less than those of the control group, the hemostasis time (30.12 ± 5.38d) and hospitalization time (5.01 ± 1.11d) of the observation group were shorter than those of the control group, and the difference was statistically significant (all P < .05). The total effective rate of hemostasis (96.00%), patient satisfaction (98.00%), and scores of physical health (88.98 ± 5.59), psychological function (91.08 ± 5.11), material life state (90.54 ± 6.46) and social function (89.59 ± 5.78) in GQOLI-74 scores in the observation group were higher than those in the control group. The incidence of complications (6.00%) in the observation group was lower than that in the control group, and the difference was statistically significant (all P < .05). Conclusion • Upper gastrointestinal bleeding is a common emergency in gastroenterology, characterized by rapid onset, severe symptoms, and quick changes. Therefore, in order to expedite the recovery of patients with acute upper gastrointestinal bleeding and ensure their safety, it is necessary to provide effective clinical emergency nursing care. Evidence-based nursing can help nurses take appropriate nursing measures based on the best and latest evidence, to meet the reasonable individualized needs of patients. Predictive nursing is a nursing model that predicts potential nursing risks in advance and takes corresponding preventive measures. It can timely and systematically address risks in nursing and promote improvements in the effectiveness of disease treatment. The combined application of evidence-based nursing and predictive nursing can improve the hemostatic efficiency of patients with upper gastrointestinal bleeding, improve the psychological state and quality of life, reduce the incidence of complications, and obtain higher satisfaction. The combined application of these two nursing models has positive implications for improving nursing efficiency, enhancing patient cooperation during emergency care, improving hemostasis effectiveness, enhancing quality of life, and fostering a harmonious nurse-patient relationship. [ABSTRACT FROM AUTHOR]

A protocol for synthesis of chalcone derivatives with a 2-pyridone subunit from N-(2-furanylmethyl) alkynamides is reported. This synthesis involves Pd/Cu-catalyzed oxidative furan-yne cyclization at room temperature in air and may proceed via nucleopalladation of the alkyne to form a vinylpalladium intermediate, with a furan ring acting as the nucleophile. [ABSTRACT FROM AUTHOR]

The glutamate transporter-1 [GLT-1 (excitatory amino acid transporter 2)] subtype of glutamate transporter ensures crisp excitatory signaling and limits excitotoxicity in the CNS. Astrocytic expression of GLT-1 is regulated during development, by neuronal activity, and in neurodegenerative diseases. Although neurons activate astrocytic expression of GLT-1, the mechanisms involved have not been identified. In the present study, astrocytes from transgenic mice that express enhanced green fluorescent protein (eGFP) under the control of a bacterial artificial chromosome (BAC) containing a very large region of DNA surrounding the GLT-1 gene (BAC GLT-1 eGFP mice) were used to assess the role of nuclear factor-κB (NF-κB) in neuron-dependent activation of the GLT-1 promoter. We provide evidence that neurons activate NF-κB signaling in astrocytes. Transduction of astrocytes from the BAC GLT-1 eGFP mice with dominantnegative inhibitors of NF-κB signaling completely blocked neuron-dependent activation of a NF-κB reporter construct and attenuated induction of eGFP. Exogenous expression of p65 and/or p50 NF-κB subunits induced expression of eGFP or GLT-1 and increased GLT-1-mediated transport activity. Using wild-type and mutant GLT-1 promoter reporter constructs, we found that NF-κB sites at -583 or -251 relative to the transcription start site were required for neuron-dependent reporter activation. Electrophoretic mobility shift and supershift assays reveal that p65 and p50 interact with these same sites ex vivo. Finally, chromatin immunoprecipitation showed that p65 and p50 interact with these sites in adult cortex, but not in kidney (a tissue that expresses no detectable GLT-1). Together, these studies strongly suggest that NF-κB contributes to neuron-dependent regulation of astrocytic GLT-1 transcription. [ABSTRACT FROM AUTHOR]

A member of the sirtuin family of NAD+-dependent deacetylases, SIRT3, is located in mammalian mitochondria and is important for regulation of mitochondrial metabolism, cell survival, and longevity. In this study, MRPL10 (mitochondrial ribosomal protein L10) was identified as the major acetylated protein in the mitochondrial ribosome. Ribosome-associated SIRT3 was found to be responsible for deacetylation of MRPL10 in an NAD+-dependent manner. We mapped the acetylated Lys residues by tandem mass spectrometry and determined the role of these residues in acetylation of MRPL10 by site-directed mutagenesis. Furthermore, we observed that the increased acetylation of MRPL10 led to an increase in translational activity of mitochondrial ribosomes in Sirt3-/- mice. In a similar manner, ectopic expression and knockdown of SIRT3 in C2C12 cells resulted in the suppression and enhancement of mitochondrial protein synthesis, respectively. Our findings constitute the first evidence for the regulation of mitochondrial protein synthesis by the reversible acetylation of the mitochondrial ribosome and characterize MRPL10 as a novel substrate of the NAD+-dependent deacetylase, SIRT3. [ABSTRACT FROM AUTHOR]

Abstract: In order to investigate the chemical characteristics of atmospheric aerosols in a regional background site, PM2.5 and PM10 were collected at Mount Gongga Station once a week in 2006. The concentrations of fifteen elements including Na, Mg, Al, K, Ca, V, Fe, Ni, Cu, Zn, As, Ag, Ba, Tl, and Pb were detected by Inductively Coupled Plasma Mass Spectrometer (ICP-MS). The results showed that Na, Mg, Al, K, Ca, Fe were the major components of elements detected in PM2.5 and PM10, occupied 89.5% and 91.3% of all the elements. Crustal enrichment factor (EF) calculation indicated that several anthropogenic heavy metals (Ni, Cu, Zn, As, Ag, Tl, Pb) were transported long distances atmospherically. The concentrations of all elements (except Na) measured in PM2.5 and PM10 in spring and winter were higher than those in summer and autumn. The backward air mass trajectory analysis suggests that northeast India may be the source region of those pollutants. [Copyright &y& Elsevier]

Glucose is the basic fuel essential for maintenance of viability and functionality of all cells. However, some neurons -- namely, glucose-inhibited (GI) neurons -- paradoxically increase their firing activity in low-glucose conditions and decrease that activity in high-glucose conditions. The ionic mechanisms mediating electric responses of GI neurons to glucose fluctuations remain unclear. Here, we showed that currents mediated by the anoctamin 4 (Ano4) channel are only detected in GI neurons in the ventromedial hypothalamic nucleus (VMH) and are functionally required for their activation in response to low glucose. Genetic disruption of the Ano4 gene in VMH neurons reduced blood glucose and impaired counterregulatory responses during hypoglycemia in mice. Activation of VMHAno4 neurons increased food intake and blood glucose, while chronic inhibition of VMHAno4 neurons ameliorated hyperglycemia in a type 1 diabetic mouse model. Finally, we showed that VMHAno4 neurons represent a unique orexigenic VMH population and transmit a positive valence, while stimulation of neurons that do not express Ano4 in the VMH (VMHnon-Ano4) suppress feeding and transmit a negative valence. Together, our results indicate that the Ano4 channel and VMHAno4 neurons are potential therapeutic targets for human diseases with abnormal feeding behavior or glucose imbalance. [ABSTRACT FROM AUTHOR]

Herein, we report regio- and stereoselective intramolecular direct arylations of N-(2-bromophenyl)-2-furancarboxamides 1 to produce spirooxindoles 2 and 5H-furo[2,3-c]quinolin-4-ones 3 under different reaction conditions. Specifically, in the presence of Pd(PPh3)4 as a catalyst, PPh3 as a ligand, and K2CO3 as a base, substrates 1 underwent intramolecular α-arylation, possibly via a Heck insertion pathway, to provide 2, with the Z-isomer being favored. When the base was t-BuOLi and R¹ was an aryl group, the reaction favored E-2, possibly via an electrophilic palladation pathway. In contrast, in the presence of PdCl2 as a catalyst, (o-OMePh)3P as a ligand, and PivOH as an additive, substrates 1 underwent intramolecular β-arylation to provide 3, possibly via a concerted metalation-deprotonation process. [ABSTRACT FROM AUTHOR]

Pancreatic ductal adenocarcinoma (PDAC) is universally acknowledged as the cancer with the highest mortality rate. Berberine has high medicinal value and has been used as an anti-cancer agent. Hence the purpose of this study was to investigate the anti-cancer effect of berberine in PDAC. Berberine was shown to have a selective anti-cancer effect on PDAC by MTT assay in vitro. Pancreatic cancer stem cells (PCSCs), regulated by epithelial-mesenchymal transition (EMT), could promote the proliferation of PDAC cells. However, berberine suppressed the proliferation and stemness of PCSCs through immunofluorescence staining, stem cell sphere assays and so forth in vitro. In vivo, berberine reduced tumor size and decreased the expression levels of Ki67, a marker of cellular proliferation, in orthotopic pancreatic tumors. In addition, berberine inhibited the EMT signaling pathway by RT-PCR and Western blotting methods both in vitro and in vivo. Our study indicates that berberine inhibits the proliferation of PDAC cells both in vivo and in vitro. The mechanism of the anti-cancer effect of berberine likely involves the inhibition of EMT. Therefore, berberine may be a novel antineoplastic drug with clinical efficacy in PDAC. [ABSTRACT FROM AUTHOR]

Mature protoplasmic astroglia in the mammalian CNS uniquely possess a large number of fine processes that have been considered primary sites to mediate astroglia to neuron synaptic signaling. However, localized mechanisms for regulating interactions between astroglial processes and synapses, especially for regulating the expression of functional surface proteins at these fine processes, are largely unknown. Previously, we showed that the loss of the RNA binding protein FMRP in astroglia disrupts astroglial mGluR5 signaling and reduces expression of the major astroglial glutamate transporter GLT1 and glutamate uptake in the cortex of Fmr1 conditional deletion mice. In the current study, by examining ribosome localization using electron microscopy and identifying mRNAs enriched at cortical astroglial processes using synaptoneurosome/translating ribosome affinity purification and RNA-Seq in WT and FMRP-deficient male mice, our results reveal interesting localization-dependent functional clusters of mRNAs at astroglial processes. We further showed that the lack of FMRP preferentially alters the subcellular localization and expression of process-localized mRNAs. Together, we defined the role of FMRP in altering mRNA localization and expression at astroglial processes at the postnatal development (P30-P40) and provided new candidate mRNAs that are potentially regulated by FMRP in cortical astroglia. [ABSTRACT FROM AUTHOR]

The article presents a study that explores the estrogen-sensitive hypothalamus-midbrain neural circuit controls thermogenesis and physical activity. It mentions that Estrogen receptor–alpha has expressed by neurons in the ventrolateral subdivision of the ventromedial hypothalamic nucleus which regulates body weight in females.

Tyrosine hydroxylase (TH), the rate-limiting enzyme in dopamine synthesis, can be regulated by phosphorylation at multiple serine residues, including serine-40. In the present study, we report a novel interaction between a key member of the novel PKC family, protein kinase Cδ(PKCδ), and TH, in which the kinase modulates dopamine synthesis by negatively regulating TH activity via protein phosphatase 2A (PP2A). We observed that PKC is highly expressed in nigral dopaminergic neurons and colocalizes with TH. Interestingly, suppression of PKCδactivity with the kinase inhibitor rottlerin, PKCδ-small interfering RNA, or with PKCδ dominant-negative mutant effectively increased a number of key biochemical events in the dopamine pathway, including TH-ser40 phosphorylation, TH enzymatic activity, and dopamine synthesis in neuronal cell culture models. Additionally, we found that PKCδ not only physically associates with the PP2A catalytic subunit (PP2Ac) but also phosphorylates the phosphatase to increase its activity. Notably, inhibition of PKCδ reduced the dephosphorylation activity of PP2A and thereby increased TH-ser40 phosphorylation, TH activity, and dopamine synthesis. To further validate our findings, we used the PKCδknock-out (PKCδ-/-) mouse model. Consistent with other results, we found greater TH-ser40 phosphorylation and reduced PP2A activity in the substantia nigra of PKCδ-/- mice than in wild-type mice. Importantly, this was accompanied by an increased dopamine level in the striatum of PKCδ-/-mice. Collectively, these results suggest that PKCδphosphorylates PP2Ac to enhance its activity and thereby reduces TH-ser40 phosphorylation and TH activity and ultimately dopamine synthesis. [ABSTRACT FROM AUTHOR]

Oxidative stress is a key apoptotic stimulus in neuronal cell death and has been implicated in the pathogenesis of many neurodegenerative disorders, including Parkinson disease (PD). Recently, we demonstrated that protein kinase C-δ (PKCδ) is an oxidative stress-sensitive kinase that can be activated by caspase-3-dependent proteolytic cleavage to induce apoptotic cell death in cell culture models of Parkinson disease (Kaul, S., Kanthasamy, A., Kitazawa, M., Anantharam, V., and Kanthasamy, A. G. (2003) Eur. J. Neurosci. 18, 1387-1401 and Kanthasamy, A. G., Kitazawa, M., Kanthasamy, A., and Anantharam, V. (2003) Antioxid. Redox. Signal 5, 609-620). Here we showed that the phosphorylation of a tyrosine residue in PKCδ can regulate the proteolytic activation of the kinase during oxidative stress, which consequently influences the apoptotic cell death in dopaminergic neuronal cells. Exposure of a mesencephalic dopaminergic neuronal cell line (N27 cells) to H2O2 (0300 µM) induced a dose-dependent increase in cytotoxicity, caspase-3 activation and PKCδ cleavage. H2O2-induced proteolytic activation of PKCδ was mediated by the activation of caspase-3. Most interestingly, both the general Src tyrosine kinase inhibitor genistein (25 µM) and the p60Src tyrosine-specific kinase inhibitor (TSKI; 5 µM) dramatically inhibited H2O2 and the Parkinsonian toxin 1-methyl-4-phenylpyridinium-induced PKCδ cleavage, kinase activation, and apoptotic cell death. H2O2 treatment also increased phosphorylation of PKCδ at tyrosine site 311, which was effectively blocked by co-treatment with TSKI. Furthermore, N27 cells overexpressing a PKCδY311F mutant protein exhibited resistance to H2O2-induced PKCδ cleavage, caspase activation, and apoptosis. To our knowledge, these data demonstrate for the first time that phosphorylation of Tyr-311 on PKCδ can regulate the proteolytic activation and proapoptotic function of the kinase in dopaminergic neuronal cells. [ABSTRACT FROM AUTHOR]

In 1990, Hendry conjectured that all Hamiltonian chordal graphs are cycle extendable. After a series of papers confirming the conjecture for a number of graph classes, the conjecture is yet refuted by Lafond and Seamone in 2015. Given that their counterexamples are not strongly chordal graphs and they are all only 2-connected, Lafond and Seamone asked the following two questions: (1) Are Hamiltonian strongly chordal graphs cycle extendable? (2) Is there an integer k such that all k-connected Hamiltonian chordal graphs are cycle extendable? Later, a conjecture stronger than Hendry's is proposed. In this paper, we resolve all these questions in the negative. On the positive side, we add to the list of cycle-extendable graphs two more graph classes, namely, Hamiltonian 4-fan-free chordal graphs, where every induced K5 e has true twins, and Hamiltonian \{ 4-fan,A\} -free chordal graphs. [ABSTRACT FROM AUTHOR]

Obesity is a serious global health problem because of its increasing prevalence and comorbidities, but its treatments are limited. The serotonin 2C receptor (5-HT2CR), a G-protein-coupled receptor, activates proopiomelanocortin (POMC) neurons in the arcuate nucleus of hypothalamus (ARH) to reduce appetite and weight gain. However, several 5-HT analogs targeting this receptor, e.g., lorcaserin (Lor), suffer from diminished efficacy to reduce weight after prolonged administration. Here, we show that barbadin (Bar), a novel b-arrestin/b2-adaptin inhibitor, can prevent 5-HT2CR internalization in cells and potentiate long-term effects of Lor to reduce appetite and body weight in male mice. Mechanistically, we demonstrate that Bar co-treatment can effectively maintain the sensitivity of the 5-HT2CR in POMCARH neurons, despite prolonged Lor exposure, thereby allowing these neurons to be activated through opening the transient receptor potential cation (TRPC) channels. Thus, our results prove the concept that inhibition of 5-HT2CR desensitization can be a valid strategy to improve the long-term weight loss effects of Lor or other 5-HT2CR agonists, and also provide an intellectual framework to develop effective long-term management of weight by targeting 5-HT2CR desensitization. [ABSTRACT FROM AUTHOR]

The loss of fragile X mental retardation protein (FMRP) causes fragile X syndrome (FXS), the most common inherited intellectual disability. How the loss of FMRP alters protein expression and astroglial functions remains essentially unknown. Herewe showed that selective loss of astroglial FMRP in vivo up-regulates a brain-enriched miRNA, miR-128-3p, in mouse and human FMRP-deficient astroglia, which suppresses developmental expression of astroglial metabotropic glutamate receptor 5 (mGluR5), a major receptor in mediating developmental astroglia to neuron communication. Selective in vivo inhibition of miR-128-3p in FMRP-deficient astroglia sufficiently rescues decreased mGluR5 function, while astroglial overexpression of miR-128-3p strongly and selectively diminishes developmental astroglial mGluR5 signaling. Subsequent transcriptome and proteome profiling further suggests that FMRP commonly and preferentially regulates protein expression through posttranscriptional, but not transcriptional, mechanisms in astroglia. Overall, our study defines an FMRP-dependent cellautonomous miR pathway that selectively alters developmental astroglial mGluR5 signaling, unveiling astroglial molecular mechanisms involved in FXS pathogenesis. [ABSTRACT FROM AUTHOR]

Ischemia not only activates cell death pathways but also triggers endogenous protective mechanisms. However, it is largely unknown what is the essence of the endogenous neuroprotective mechanisms induced by preconditioning. In this study we demonstrated that systemic injection of JZL195, a selective inhibitor of eCB clearance enzymes, induces in vivo long-term depression at CA3-CA1 synapses and at PrL-NAc synapses produces neuroprotection. JZL195-elicited long-term depression is blocked by AM281, the antagonist of cannabinoid 1 receptor (CB1R) and is abolished in mice lacking cannabinoid CB1 receptor (CB1R) in astroglial cells, but is conserved in mice lacking CB1R in glutamatergic or GABAergic neurons. Blocking the glutamate NMDA receptor and the synaptic trafficking of glutamate AMPA receptor abolishes both long-term depression and neuroprotection induced by JZL195. Mice lacking CB1R in astroglia show decreased neuronal death following cerebral ischemia. Thus, an acute elevation of extracellular eCB following eCB clearance inhibition results in neuroprotection through long-term depression induction after sequential activation of astroglial CB1R and postsynaptic glutamate receptors. [ABSTRACT FROM AUTHOR]

The molecular signature and functional properties of astroglial subtypes in the adult CNS remain largely undefined. By using translational ribosome affinity purification followed by RNA-Seq, we profiled astroglial ribosome-associated (presumably translating) mRNAs in major cortical and subcortical brain regions (cortex, hippocampus, caudate-putamen, nucleus accumbens, thalamus, and hypothalamus) of BACfl/d/tf/l-translational ribosome affinity purification (TRAP) mice (both sexes). We found that the expression of astroglial translating mRNAs closely follows the dorsoventral axis, especially from cortex/hippocampus to thalamus/hypothalamus posteriorly. This region-specific expression pattern of genes, such as synaptogenic modulator spare and transcriptional factors (emx2, lhx2, and hopx), was validated by qRT-PCR and immunostaining in brain sections. Interestingly, cortical or subcortical astrocytes selectively promote neurite growth and synaptic activity of neurons only from the same region in mismatched cocultures, exhibiting regionmatched astrocyte to neuron communication. Overall, these results generated new molecular signature of astrocyte types in the adult CNS, providing insights into their origin and functional diversity. [ABSTRACT FROM AUTHOR]

Medium- or late-maturing varieties of rice (Oryza sativa L.) that are planted in agroecosystems in the middle and lower reaches of the Yangtze Valley of China always encounter cold stress during the late grain-filling stage. Generally, grain yield and yield components are adversely affected under such circumstances. To alleviate these negative effects, salicylic acid (SA; i.e., SA0 [control, 0 mg L-1], SA100 [100 mg L-1], SA200 [200 mg L-1], SA300 [300 mg L-1], and SA400 [400 mg L-1]) was exogenously sprayed on plants of three rice cultivars at full heading in the field at the experimental base of China National Rice Research Institute (CNRRI) in Fuyang City, China (30°03' N, 119°57' E, 11 m asl). The results indicated that the mean grain-filling rate and grain weight of the inferior grains were significantly increased under the SA200 (200 mg L-1) treatment and correspondingly contributed to a grain yield increase of 5.0 to 10.1% in comparison with the control. Further analysis showed that the SA200 treatment significantly increased the activity of the starch branching enzyme in inferior grains over the entire grain-filling stage. Additionally, the photosynthetic rate, chlorophyll content, and soluble protein content of the flag leaf, which precisely reflected the senescence status, were significantly increased under the SA200 treatment, especially during late maturity under mild cold stress. We speculated that improved physiological changes during the late grain-filling stage account for the increased grain weight and grain yield. Therefore, application of SA was a promising method of alleviating the adverse effects that were induced by mild cold stress on the grain yield of rice in the middle and lower reaches of the Yangtze Valley of China. [ABSTRACT FROM AUTHOR]

How the loss of fragile X mental retardation protein (FMRP) in different brain cell types, especially in non-neuron glial cells, induces fragile X syndrome (FXS) phenotypes has just begun to be understood. In the current study, we generated inducible astrocyte-specific Fmrl conditional knock-out mice (i-astro-Fmrl-cKO) and restoration mice (i-astro-Fmrl-cON) to study the in vivo modulation of FXS synaptic phenotypes by astroglial FMRP. We found that functional expression of glutamate transporter GLT1 is 40% decreased in i-astro-FmrJ-cKO somatosensory cortical astrocytes in vivo, which can be fully rescued by the selective re-expression of FMRP in astrocytes in i-astro-Fmrl-cON mice. Although the selective loss of astroglial FMRP only modestly increases spine density and length in cortical pyramidal neurons, selective re-expression of FMRP in astrocytes significantly attenuates abnormal spine morphology in these neurons of i-astro-Fmri-cON mice. Moreover, we found that basal protein synthesis levels and immunoreactivity of phosphorylated S6 ribosomal protein (p-s6P) is significantly increased in i-astro-Fmri-cKO mice, while the enhanced cortical protein synthesis observed in Fmrl KO mice is mitigated in i-astro-Fmr/-cON mice. Furthermore, ceftriaxone-mediated upregulation of surface GLT1 expression restores functional glutamate uptake and attenuates enhanced neuronal excitability in Fmrl KO mice. In particular, ceftriaxone significantly decreases the growth rate of abnormally accelerated body weight and completely corrects spine abnormality in Fmrl KO mice. Together, these results show that the selective loss of astroglial FMRP contributes to cortical synaptic deficits in FXS, presumably through dysregulated astroglial glutamate transporter GLT1 and impaired glutamate uptake. These results suggest the involvement of astrocyte-mediated mechanisms in the pathogenesis of FXS. [ABSTRACT FROM AUTHOR]

Background: Neonatal astrocytes are diverse in origin, and undergo dramatic change in gene expression, morphological differentiation and syncytial networking throughout development. Neonatal astrocytes also play multifaceted roles in neuronal circuitry establishment. However, the extent to which neonatal astrocytes differ from their counterparts in the adult brain remains unknown. Results: Based on ALDH1L1-eGFP expression or sulforhodamine 101 staining, neonatal astrocytes at postnatal day 1-3 can be reliably identified in hippocampal stratum radiatum. They exhibit a more negative resting membrane potential (VM), -85 mV, than mature astrocytes, -80 mV and a variably rectifying whole-cell current profile due to complex expression of voltage-gated outward transient K+ (IKa), delayed rectifying K+ (IKd) and inward K+ (IKin) conductances. Differing from NG2 glia, depolarization-induced inward Na+ currents (INa) could not be detected in neonatal astrocytes. A quasi-physiological VM of .69 mV was retained when inwardly rectifying Kir4.1 was inhibited by 100 μM Ba2+ in both wild type and TWIK-1/TREK-1 double gene knockout astrocytes, indicating expression of additional leak K+ channels yet unknown. In dual patch recording, electrical coupling was detected in 74% (14/19 pairs) of neonatal astrocytes with largely variable coupling coefficients. The increasing gap junction coupling progressively masked the rectifying K+ conductances to account for an increasing number of linear voltage-to-current relationship passive astrocytes (PAs). Gap junction inhibition, by 100 μM meclofenamic acid, substantially reduced membrane conductance and converted all the neonatal PAs to variably rectifying astrocytes. The low density expression of leak K+ conductance in neonatal astrocytes corresponded to a ~50% less K+ uptake capacity compared to adult astrocytes. Conclusions: Neonatal astrocytes predominantly express a variety of rectifying K+ conductances, form discrete cell-to-cell gap junction coupling and are deficient in K+ homeostatic capacity. [ABSTRACT FROM AUTHOR]

Estrogen receptor-α (ERα) activity in the brain prevents obesity in both males and females. However, the ERα-expressing neural populations that regulate body weight remain to be fully elucidated. Here we showed that single-minded-1 (SIM1) neurons in the medial amygdala (MeA) express abundant levels of ERα. Specific deletion of the gene encoding ERa (FsrT) from SIM1 neurons, which are mostly within the MeA, caused hypoactivity and obesity in both male and female mice fed with regular chow, increased susceptibility to diet-induced obesity (DIO) in males but not in females, and blunted the body weight-lowering effects of a glucagon-like peptide-1-estrogen (GLP-1-estrogen) conjugate. Furthermore, selective adeno-associated virus-mediated deletion of Esrl in the MeA of adult male mice produced a rapid body weight gain that was associated with remarkable reductions in physical activity but did not alter food intake. Conversely, overexpression of ERa in the MeA markedly reduced the severity of DIO in male mice. Finally, an ERa agonist depolarized MeA SIM1 neurons and increased their firing rate, and designer receptors exclusively activated by designer drug-mediated (DREADD-mediated) activation of these neurons increased physical activity in mice. Collectively, our results support a model where ERa signals activate MeA neurons to stimulate physical activity, which in turn prevents body weight gain. [ABSTRACT FROM AUTHOR]

Binge eating afflicts approximately 5% of US adults, though effective treatments are limited. Here, we showed that estrogen replacement substantially suppresses binge-like eating behavior in ovariectomized female mice. Estrogen-dependent inhibition of binge-like eating was blocked in female mice specifically lacking estrogen receptor-α (ERα) in serotonin (5-HT) neurons in the dorsal raphe nuclei (DRN). Administration of a recently developed glucagon-like peptide-1-estrogen (GLP-1-estrogen) conjugate designed to deliver estrogen to GLP1 receptor-enhanced regions effectively targeted bioactive estrogens to the DRN and substantially suppressed binge-like eating in ovariectomized female mice. Administration of GLP-1 alone reduced binge-like eating, but not to the same extent as the GLP-1-estrogen conjugate. Administration of ERα-selective agonist propylpyrazole triol (PPT) to murine DRN 5-HT neurons activated these neurons in an ER α-dependent manner. PPT also inhibited a small conductance Ca2+-activated K+ (SK) current; blockade of the SK current prevented PPT-induced activation of DRN 5-HT neurons. Furthermore, local inhibition of the SK current in the DRN markedly suppressed binge-like eating in female mice. Together, our data indicate that estrogens act upon ERα to inhibit the SK current in DRN 5-HT neurons, thereby activating these neurons to suppress binge-like eating behavior and suggest ERα and/or SK current in DRN 5-HT neurons as potential targets for anti-binge therapies. [ABSTRACT FROM AUTHOR]

Functional maturation of astroglia is characterized by the development of a unique, ramified morphology and the induction of important functional proteins, such as glutamate transporter GLT1. Although pathways regulating the early fate specification of astroglia have been characterized, mechanisms regulating postnatal maturation of astroglia remain essentially unknown. Here we used a new in vivo approach to illustrate and quantitatively analyze developmental arborization of astroglial processes. Our analysis found a particularly high increase in the number of VGluTl + neuronal glutamatergic synapses that are ensheathed by processes from individual developing astroglia from postnatal day (P) 14 to P26, when astroglia undergo dramatic postnatal maturation. Subsequent silencing of VGluTl + synaptic activity in VGluTl KO mice significantly reduces astroglial domain growth and the induction of GLT1 in the cortex, but has no effect on astroglia in the hypothalamus, where non-VGluTl + synaptic signaling predominates. In particular, electron microscopy analysis showed that the loss of VGluTl + synaptic signaling significantly decreases perisynaptic enshealthing of astroglial processes on synapses. To further determine whether synaptically released glutamate mediates VGluTl + synaptic signaling, we pharmacologically inhibited and genetically ablated metabotropic glutamate receptors (mGluRs, especially mGluR5) in developing cortical astroglia and found that developmental arborization of astroglial processes and expression of functional proteins, such as GLT1, is significantly decreased. In summary, our genetic analysis provides new in vivo evidence that VGluTl+ glutamatergic signaling, mediated by the astroglial mGluR5 receptor, regulates the functional maturation of cortical astroglia during development. These results elucidate a new mechanism for regulating the developmental formation of functional neuron-glia synaptic units. [ABSTRACT FROM AUTHOR]

Perisynaptic astrocytes express important glutamate transporters, especially excitatory amino acid transporter 2 (EAAT2, rodent analog GLT1) to regulate extracellular glutamate levels and modulate synaptic activation. In this study, we investigated an exciting new pathway, the exosome-mediated transfer of microRNA (in particular, miR-124a), in neuron-to-astrocyte signaling. Exosomes isolated from neuron-conditioned medium contain abundant microRNAs and small RNAs. These exosomes can be directly internalized into astrocytes and increase astrocyte miR-124a and GLT1 protein levels. Direct miR-124a transfection also significantly and selectively increases protein (but not mRNA) expression levels of GLT1 in cultured astrocytes. Consistent with our in vitro findings, intrastriatal injection of specific antisense against miR-124a into adult mice dramatically reduces GLT1 protein expression and glutamate uptake levels in striatum without reducing GLT1 mRNA levels. MiR- 124a-mediated regulation of GLT1 expression appears to be indirect and is not mediated by its suppression of the putative GLT1 inhibitory ligand ephrinA3. Moreover, miR-124a is selectively reduced in the spinal cord tissue of end-stage SOD1 G93A mice, the mouse model of ALS. Subsequent exogenous delivery of miR-124a in vivo through stereotaxic injection significantly prevents further pathological loss of GLT1 proteins, as determined by GLT1 immunoreactivity in SOD1 G93A mice. Together, our study characterized a new neuron-to-astrocyte communication pathway and identified miRNAs that modulate GLT1 protein expression in astrocytes in vitro and in vivo. [ABSTRACT FROM AUTHOR]

We recently demonstrated that protein kinase Cδ (PKCδ), an important member of the novel PKC family, is a key oxidative stresssensitive kinase that can be activated by caspase-3-dependent proteolytic cleavage to induce dopaminergic neuronal cell death. We now report a novel association between α-synuclein (αsyn), a protein associated with the pathogenesis of Parkinson's disease, and PKCδ, in which αsyn negatively modulates the p300- and nuclear factor-κB (NFκB)-dependent transactivation to downregulate proapoptotic kinase PKCδ expression and thereby protects against apoptosis in dopaminergic neuronal cells. Stable expression of human wild-type αsyn at physiological levels in dopaminergic neuronal cells resulted in an isoform-dependent transcriptional suppression of PKCδ expression without changes in the stability of mRNA and protein or DNA methylation. The reduction in PKCδ transcription was mediated, in part, through the suppression of constitutive NFκB activity targeted at two proximal PKCδ promoter κB sites. This occurred independently of NFκB/IκBα (inhibitor of κBα) nuclear translocation but was associated with decreased NFκB-p65 acetylation. Also, αsyn reduced p300 levels and its HAT (histone acetyltransferase) activity, thereby contributing to diminished PKCδ transactivation. Importantly, reduced PKCδ and p300 expression also were observed within nigral dopaminergic neurons in αsyn-transgenic mice. These findings expand the role of αsyn in neuroprotection by modulating the expression of the key proapoptotic kinase PKCδ in dopaminergic neurons. [ABSTRACT FROM AUTHOR]

A new genetic map of maize, ISU-IBM Map4, that integrates 2029 existing markers with 1329 new indel polymorphism (IDP) markers has been developed using intermated recombinant inbred lines (IRILs) from the intermated B73 3 Mo17 (IBM) population. The website http://magi.plantgenomics.iastate.edu provides access to IDP primer sequences, sequences from which IDP primers were designed, optimized marker-specific PCR conditions, and polymorphism data for all IDP markers. This new gene-based genetic map will facilitate a wide variety of genetic and genomic research projects, including map-based genome sequencing and gene cloning. The mosaic structures of the genomes of 91 IRILs, an important resource for identifying and mapping QTL and eQTL, were defined. Analyses of segregation data associated with markers genotyped in three B73/Mo17-derived mapping populations (F2, Syn5, and IBM) demonstrate that allele frequencies were significantly altered during the development of the IBM IRILs. The observations that two segregation distortion regions overlap with maize flowering-time QTL suggest that the altered allele frequencies were a consequence of inadvertent selection. Detection of two-locus gamete disequilibrium provides another means to extract functional genomic data from well-characterized plant RILs. [ABSTRACT FROM AUTHOR]