Interactive audio human organ model combined with team-based learning improves the motivation and performance of nursing students in learning anatomy and physiology.

Among the basic medical sciences, anatomy and physiology (anatomy & physiology) is a fundamental subject for students majoring in nursing. Due to its diversity and difficulty, nursing students experience stress when studying it. Previous graduates generally presented lower achievements in anatomy & physiology than in other nursing-related subjects in the National Council Licensure Examination-Registered Nurse, indicating that anatomy & physiology education requires improvement. Accordingly, we examined the impact of innovative teaching on students' motivation and performance when learning anatomy & physiology through a quasi-experimental pre-/post-test design. For innovative teaching, we used the novel interactive audio human organ model, followed by team-based learning. The participants were 200 lower-grade students in the nursing department of a junior college in Taiwan, divided into two groups receiving innovative teaching (experimental group) or traditional teaching (control group). Questionnaire surveys were administered, and the collected data were statistically analyzed. The innovative teaching in anatomy & physiology improved learning motivation, especially in terms of affect, executive volition, and learning performance. The essential components of learning motivation, such as value, expectation, affect, and executive volition, were positively correlated with the reaction levels of learning performance. Regarding the improvement in academic performance, the experimental group performed significantly better than the control group. The use of innovative teaching in class enhances students' learning motivation and learning performance when studying anatomy & physiology. Interactive teaching aids enhance the enjoyment of learning anatomy & physiology while facilitating in-depth exploration of the human organs and systems.

SGLT2 Inhibitor Canagliflozin Alleviates High Glucose-Induced Inflammatory Toxicity in BV-2 Microglia.

Patients with diabetes mellitus can experience hyperglycemia, which affects brain function and produces cognitive impairment or neurodegeneration. Neuroinflammation is an important cause of cognitive dysfunction. Sodium-glucose cotransporter 2 (SGLT2) inhibitors are antihyperglycemic agents that reportedly possess anti-inflammatory properties and may produce beneficial cognitive effects. We hypothesized that SGLT2 inhibitors alleviate hyperglycemia-related inflammation in brain immune cells. Cultured BV-2 microglia were exposed to high glucose (HG) in the absence or presence of SGLT2 inhibitors including canagliflozin (Cana), dapagliflozin (Dapa), empagliflozin (Empa), and ertugliflozin (Ertu). Afterward, we evaluated the cytotoxic and inflammatory responses by specific biochemical assays. Treatments with non-toxic Cana or Dapa, but not Empa or Ertu, inhibited proliferation without cell death. Only Cana rescued BV-2 microglia from HG-induced cytotoxicity, including apoptosis or autophagic degradation. None of SGLT2 inhibitors affected the HG-stimulated induction of stress proteins HO-1 and HSP70. Also, compared to the other three SGLT2 inhibitors, Cana was better at inhibiting HG-induced oxidative/inflammatory stress, as evidenced by its ability to repress proinflammatory factors (e.g., oxygen free radicals, iNOS, NLRP3, IL-1ß, and TNF-α) other than COX-2. Cana's action to alleviate HG insults was mediated not by altering SGLT2 protein expression, but by reducing HG-stimulated signaling activities of NFκB, JNK, p38, and PI3K/Akt pathways. Particularly, Cana imitated the effects of NFκB inhibitor on HG-induced iNOS and COX-2. Of the four SGLT2 inhibitors, Cana provided BV-2 microglia with the best protection against HG-induced inflammatory toxicity. Thus, Cana may help to reduce innate neuroimmune damage caused by hyperglycemia.

Bisphenol a Induces Autophagy Defects and AIF-Dependent Apoptosis via HO-1 and AMPK to Degenerate N2a Neurons.

Bisphenol A (BPA) is an environmental contaminant widely suspected to be a neurological toxicant. Epidemiological studies have demonstrated close links between BPA exposure, pathogenetic brain degeneration, and altered neurobehaviors, considering BPA a risk factor for cognitive dysfunction. However, the mechanisms of BPA resulting in neurodegeneration remain unclear. Herein, cultured N2a neurons were subjected to BPA treatment, and neurotoxicity was assessed using neuronal viability and differentiation assays. Signaling cascades related to cellular self-degradation were also evaluated. BPA decreased cell viability and axon outgrowth (e.g., by down-regulating MAP2 and GAP43), thus confirming its role as a neurotoxicant. BPA induced neurotoxicity by down-regulating Bcl-2 and initiating apoptosis and autophagy flux inhibition (featured by nuclear translocation of apoptosis-inducing factor (AIF), light chain 3B (LC3B) aggregation, and p62 accumulation). Both heme oxygenase (HO)-1 and AMP-activated protein kinase (AMPK) up-regulated/activated by BPA mediated the molecular signalings involved in apoptosis and autophagy. HO-1 inhibition or AIF silencing effectively reduced BPA-induced neuronal death. Although BPA elicited intracellular oxygen free radical production, ROS scavenger NAC exerted no effect against BPA insults. These results suggest that BPA induces N2a neurotoxicity characterized by AIF-dependent apoptosis and p62-related autophagy defects via HO-1 up-regulation and AMPK activation, thereby resulting in neuronal degeneration.

Acute glucose fluctuation impacts microglial activity, leading to inflammatory activation or self-degradation.

Diabetes mellitus is associated with an increased risk of Alzheimer's dementia and cognitive decline. The cause of neurodegeneration in chronic diabetic patients remains unclear. Changes in brain microglial activity due to glycemic fluctuations may be an etiological factor. Here, we examined the impact of acute ambient glucose fluctuations on BV-2 microglial activity. Biochemical parameters were assayed and showed that the shift from normal glucose (NG; 5.5 mM) to high glucose (HG; 25 mM) promoted cell growth and induced oxidative/inflammatory stress and microglial activation, as evidenced by increased MTT reduction, elevated pro-inflammatory factor secretion (i.e., TNF-α and oxygen free radicals), and upregulated expression of stress/inflammatory proteins (i.e., HSP70, HO-1, iNOS, and COX-2). Also, LPS-induced inflammation was enlarged by an NG-to-HG shift. In contrast, the HG-to-NG shift trapped microglia in a state of metabolic stress, which led to apoptosis and autophagy, as evidenced by decreased Bcl-2 and increased cleaved caspase-3, TUNEL staining, and LC3B-II expression. These stress episodes were primarily mediated through MAPKs, PI3K/Akt, and NF-κB cascades. Our study demonstrates that acute glucose fluctuation forms the stress that alters microglial activity (e.g., inflammatory activation or self-degradation), representing a novel pathogenic mechanism for the continued deterioration of neurological function in diabetic patients.

1,25-Dihydroxyvitamin D3 modulates the effects of sublethal BPA on mitochondrial function via activating PI3K-Akt pathway and 17ß-estradiol secretion in rat granulosa cells.

Bisphenol A (BPA), an endocrine-disrupting chemical, is capable of producing reproductive toxicity. BPA results in mitochondrial DNA (mtDNA) deletion and mitochondrial dysfunction; however, the effect of BPA on the mitochondria of ovarian granulosa cells is not clear. Further, 1,25-dihydroxyvitamin D3 (1,25D3) may play a role in reproduction, because its receptor, VDR, contributes to the inhibition of oxidative stress and predominantly exists in the nuclei of granulosa cells. Hence, the role of 1,25D3 in BPA-mediated effects on mitochondrial function was examined in this study. Primary rat granulosa cells treated with BPA, 1,25D3, or both were subjected to molecular/biochemical assays to measure cell survival, mtDNA content, mtDNA deletion, superoxide dismutase activity, levels of proteins related to mitochondrial biogenesis, and mitochondrial function. We found that cell viability was dose-dependently reduced and reactive oxygen species (ROS) levels were increased by BPA treatment. BPA administration elevated Mn-superoxide dismutase (MnSOD) expression but negatively regulated total SOD activity. 1,25D3 treatment alone increased 17ß-estradiol secretion, ATP production, and cellular oxygen consumption. In cells treated with both agents, 1,25D3 enhanced BPA-induced MnSOD protein upregulation and blocked the BPA-mediated decline in total SOD activity. Furthermore, 1,25D3 attenuated BPA-mediated mtDNA deletion but showed no effect on BPA-induced increases in mtDNA content. Although BPA had no influence on the levels of peroxisome proliferator-activated receptor-γ coactivator-1 α, nuclear respiratory factor-1, mitochondrial transcription factor A, or cytochrome c oxidase subunit IV, 1,25D3 plus BPA markedly increased mitochondrial biogenesis-related protein expression via the PI3K-Akt pathway. Moreover, BPA-mediated negative regulation of cytochrome c oxidase subunit I levels and 17ß-estradiol secretion was attenuated by 1,25D3 pre-treatment. Our results suggest that 1,25D3 attenuates BPA-induced decreases in 17ß-estradiol and that treatment with 1,25D3 plus BPA regulates granulosa cell mitochondria by elevating mitochondrial biogenesis-related protein levels.

Electronegative Low-Density Lipoprotein L5 Impairs Viability and NGF-Induced Neuronal Differentiation of PC12 Cells via LOX-1.

There have been striking associations of cardiovascular diseases (e.g., atherosclerosis) and hypercholesterolemia with increased risk of neurodegeneration including Alzheimer's disease (AD). Low-density lipoprotein (LDL), a cardiovascular risk factor, plays a crucial role in AD pathogenesis; further, L5, a human plasma LDL fraction with high electronegativity, may be a factor contributing to AD-type dementia. Although L5 contributing to atherosclerosis progression has been studied, its role in inducing neurodegeneration remains unclear. Here, PC12 cell culture was used for treatments with human LDLs (L1, L5, or oxLDL), and subsequently cell viability and nerve growth factor (NGF)-induced neuronal differentiation were assessed. We identified L5 as a neurotoxic LDL, as demonstrated by decreased cell viability in a time- and concentration-dependent manner. Contrarily, L1 had no such effect. L5 caused cell damage by inducing ATM/H2AX-associated DNA breakage as well as by activating apoptosis via lectin-like oxidized LDL receptor-1 (LOX-1) signaling to p53 and ensuring cleavage of caspase-3. Additionally, sublethal L5 long-termly inhibited neurite outgrowth in NGF-treated PC12 cells, as evidenced by downregulation of early growth response factor-1 and neurofilament-M. This inhibitory effect was mediated via an interaction between L5 and LOX-1 to suppress NGF-induced activation of PI3k/Akt cascade, but not NGF receptor TrkA and downstream MAPK pathways. Together, our data suggest that L5 creates a neurotoxic stress via LOX-1 in PC12 cells, thereby leading to impairment of viability and NGF-induced differentiation. Atherogenic L5 likely contributes to neurodegenerative disorders.

Highly electronegative low-density lipoprotein L5 evokes microglial activation and creates a neuroinflammatory stress via Toll-like receptor 4 signaling.

Atherogenic risk factors, such as hypercholesterolemia, are associated with increased risk of neurodegeneration, especially Alzheimer's dementia. Human plasma electronegative low-density lipoprotein [LDL(-)], especially L5, may serve as an important contributing factor. L5 promoting an inflammatory action in atherosclerosis has been extensively studied. However, the role of L5 in inducing neuroinflammation remains unknown. Here, we examined the impact of L5 on immune activation and cell viability in cultured BV-2 microglia. BV-2 cells treated with lipopolysaccharide or human LDLs (L1, L5, or oxLDL) were subjected to molecular/biochemical assays for measuring microglial activation, levels of inflammatory factors, and cell survival. A transwell BV-2/N2a co-culture was used to assess N2a cell viability following BV-2 cell exposure to L5. We found that L5 enables the activation of microglia and elicits an inflammatory response, as evidenced by increased oxygen/nitrogen free radicals (nitric oxide, reactive oxygen species, and peroxides), elevated tumor necrosis factor-α levels, decreased basal interleukin-10 levels, and augmented production of pro-inflammatory proteins (inducible nitric oxide synthase and cyclooxygenase-2). L5 also triggered BV-2 cell death primarily via apoptosis. These effects were markedly disrupted by the application of signaling pathway inhibitors, thus demonstrating that L5 interacts with Toll-like receptor 4 to modulate multiple pathways, including MAPKs, PI3K/Akt, and NF-κB. Decreased N2a cell viability in a transwell co-culture was mainly ascribed to L5-induced BV-2 cell activation. Together, our data suggest that L5 creates a neuroinflammatory stress via microglial Toll-like receptor 4, thereby leading to the death of BV-2 microglia and coexistent N2a cells. Atherogenic L5 possibly contributes to neuroinflammation-related neurodegeneration.

Nitroxide antioxidant as a potential strategy to attenuate the oxidative/nitrosative stress induced by hydrogen peroxide plus nitric oxide in cultured neurons.

Oxidative/nitrosative stress contributes to the etiology of the neurological disorders, including ischemic stroke and chronic neurodegeneration. Neurotoxic modifications mediated by reactive oxygen species (ROS) or reactive nitrogen species (RNS) are closely associated with the destruction of key macromolecules and inactivation of antioxidant enzymes, which compromises antioxidant defenses. Approaches to expel ROS/RNS and alleviate toxic oxidative/nitrosative stress in neurons have not completely been defined. Here, we aimed to evaluate the efficacy of various antioxidants that serve as the neuroprotectors under a toxic stress created by ROS plus nitric oxide (NO). Sublytic concentrations of hydrogen peroxide (H2O2) plus NO donor S-nitroso-N-acetyl-D, L-penicillamine (SNAP) enabled to induce a toxic oxidative/nitrosative stress through activating both p38 MAPK and p53 cascades, and cause DNA damage and protein tyrosine nitration in primary neuronal cultures. After comparing six antioxidants, including superoxide dimutase (SOD), catalase, 2,2,6,6-tetramethyl-1-piperidinoxyl (TEMPO), N-acetylcysteine, dimethylthiourea, and uric acid, TEMPO was the superior antioxidant that comprehensively and efficaciously decreased H2O2 plus SNAP-evoked activation of stress cascades of p38 MAPK and p53, production of NO, ROS, and peroxynitrite, double-strand breaks of DNA, and nitration of protein tyrosine residues. SOD increased the peroxynitrite formation and was unable to reduce the level of protein nitration. All antioxidants tested, except SOD, effectively reduced neuronal damage and DNA breakage caused by the toxic H2O2/SNAP combination. In conclusion, these results suggest that TEMPO ensures excellent ROS/RNS clearance and stress-signaling inhibition, thus effectively rescuing neurons from ROS/H2O2 plus NO/SNAP-induced insult. This study reveals a potential strategy for nitroxide antioxidants as a therapeutic agent against oxidative/nitrosative neurotoxicity.

1,25-Dihydroxyvitamin D3 increases testosterone-induced 17beta-estradiol secretion and reverses testosterone-reduced connexin 43 in rat granulosa cells.

BACKGROUND: Aromatase converts testosterone into 17beta-estradiol in granulosa cells, and the converted 17beta-estradiol contributes to follicular maturation. Additionally, excessive testosterone inhibits aromatase activity, which can lead to concerns regarding polycystic ovary syndrome (PCOS). Generally, 1,25-dihydroxyvitamin D3 (1,25D3) supplements help to improve the symptoms of PCOS patients who exhibit low blood levels of 1,25D3. Therefore, this study investigated the interaction effects of 1,25D3 and testosterone on estrogenesis and intercellular connections in rat granulosa cells. METHODS: Primary cultures of granulosa cells were treated with testosterone or testosterone plus 1,25D3, or pre-treated with a calcium channel blocker or calcium chelator. Cell lysates were subjected to western blot analysis to determine protein and phosphorylation levels, and 17beta-estradiol secretion was examined using a radioimmunoassay technique. Cell viability was evaluated by MTT reduction assay. Connexin 43 (Cx43) mRNA and protein expression levels were assessed by qRT-PCR, western blot, and immunocytochemistry. RESULTS: Testosterone treatment (0.1 and 1 microg/mL) increased aromatase expression and 17beta-estradiol secretion, and the addition of 1,25D3 attenuated testosterone (1 microg/mL)-induced aromatase expression but improved testosterone-induced 17beta-estradiol secretion. Furthermore, testosterone-induced aromatase phosphotyrosine levels increased at 10 min, 30 min and 1 h, whereas 1,25D3 increased the longevity of the testosterone effect to 6 h and 24 h. Within 18-24 h of treatment, 1,25D3 markedly enhanced testosterone-induced 17beta-estradiol secretion. Additionally, pre-treatment with a calcium channel blocker nifedipine or an intracellular calcium chelator BAPTA-AM reduced 1,25D3 and testosterone-induced 17beta-estradiol secretion. Groups that underwent testosterone treatment exhibited significantly increased estradiol receptor beta expression levels, which were not affected by 1,25D3. Neither testosterone nor 1,25D3 altered 1,25D3 receptor expression. Finally, at high doses of testosterone, Cx43 protein expression was decreased in granulosa cells, and this effect was reversed by co-treatment with 1,25D3. CONCLUSIONS: These data suggest that 1,25D3 potentially increases testosterone-induced 17beta-estradiol secretion by regulating aromatase phosphotyrosine levels, and calcium increase is involved in both 1,25D3 and testosterone-induced 17beta-estradiol secretion. 1,25D3 reverses the inhibitory effect of testosterone on Cx43 expression in granulosa cells.

Widely applicable synthesis of enantiomerically pure tertiary alkyl-containing 1-alkanols by zirconium-catalyzed asymmetric carboalumination of alkenes and palladium- or copper-catalyzed cross-coupling.

A highly enantioselective and widely applicable method for the synthesis of various chiral 2-alkyl-1-alkanols, especially those of feeble chirality, has been developed. It consists of zirconium-catalyzed asymmetric carboalumination of alkenes (ZACA), lipase-catalyzed acetylation, and palladium- or copper-catalyzed cross-coupling. By virtue of the high selectivity factor (E) associated with iodine, either (S)- or (R)-enantiomer of 3-iodo-2-alkyl-1-alkanols (1), prepared by ZACA reaction of allyl alcohol, can be readily purified to the level of ≥99% ee by lipase-catalyzed acetylation. A variety of chiral tertiary alkyl-containing alcohols, including those that have been otherwise difficult to prepare, can now be synthesized in high enantiomeric purity by Pd- or Cu-catalyzed cross-coupling of (S)-1 or (R)-2 for introduction of various primary, secondary, and tertiary carbon groups with retention of all carbon skeletal features. These chiral tertiary alkyl-containing alcohols can be further converted into the corresponding acids with full retention of the stereochemistry. The synthetic utility of this method has been demonstrated in the highly enantioselective (≥99% ee) and efficient syntheses of (R)-2-methyl-1-butanol and (R)- and (S)-arundic acids.

L-ascorbate attenuates methamphetamine neurotoxicity through enhancing the induction of endogenous heme oxygenase-1.

Methamphetamine (METH) is a drug of abuse which causes neurotoxicity and increased risk of developing neurodegenerative diseases. We previously found that METH induces heme oxygenase (HO)-1 expression in neurons and glial cells, and this offers partial protection against METH toxicity. In this study, we investigated the effects of l-ascorbate (vitamin C, Vit. C) on METH toxicity and HO-1 expression in neuronal/glial cocultures. Cell viability and damage were evaluated by 3-(4,5-dimethylthianol-2-yl)-2,5 diphenyl tetrazolium bromide (MTT) reduction and lactate dehydrogenase (LDH) release, respectively. Neuronal and glial localization of HO-1 were identified by double immunofluorescence staining. Reactive oxygen species (ROS) production was measured using the fluorochrome 2',7'-dichlorofluorescin diacetate. HO-1 mRNA and protein expression were examined by RT-qPCR and Western blotting, respectively. Results show that Vit. C induced HO-1 mRNA and protein expressions in time- and concentration-dependent manners. Inhibition of p38 mitogen-activated protein kinase (MAPK) but not extracellular signal-regulated kinase (ERK) significantly blocked induction of HO-1 by Vit. C. HO-1 mRNA and protein expressions were significantly elevated by a combination of Vit. C and METH, compared to either Vit. C or METH alone. Pretreatment with Vit. C enhanced METH-induced HO-1 expression and attenuated METH-induced ROS production and neurotoxicity. Pharmacological inhibition of HO activity abolished suppressive effects of Vit. C on METH-induced ROS production and attenuated neurotoxicity. We conclude that induction of HO-1 expression contributes to the attenuation of METH-induced ROS production and neurotoxicity by Vit. C. We suggest that HO-1 induction by Vit. C may serve as a strategy to alleviate METH neurotoxicity.

Highly(≥98%) Stereo- and Regioselective Trisubstituted Alkene Synthesis of Wide Applicability via 1-Halo-1-alkyne Hydroboration-Tandem Negishi-Suzuki Coupling or Organoborate Migratory Insertion Protocol.

(Z)-1-Halo-1-alkenylboranes (7), preparable in 82-90% yields as ≥98% isomerically pure compounds via hydroboration of 1-halo-1-alkynes, have been converted to a wide range of trisubstituted alkenes via three different routes in the tail-to-head (T-to-H) direction, i.e., (i) Palladium-catalyzed Negishi-Suzuki tandem alkenylation, (ii) treatment of 7 with organolithium or Grignard reagents to generate α-bromo-1-alkenylboronate complexes (10) that can undergo migratory insertion of a carbon group (R2) to form (E)-alkenylboranes (11) with inversion of alkene configuration (≥98% inversion), followed by fluoride-promoted Suzuki alkenylation, and (iii) Negishi coupling to generate (Z)-alkenylboranes (8) in ≥98% retention of configuration, followed by treatment with organolithium or Grignard reagents to produce trisubstituted alkenes with reversed stereo configurations. The synthetic utility of the present methodology has been demonstrated in the highly selective synthesis of side chain (4) of scyphostatin in 28% yield over nine steps in the longest linear sequence from allyl alcohol. Thus, this new tandem protocol has been emerged as the most widely applicable and highly selective route to trisubstituted alkenes including those that are otherwise difficult to prepare.

Highly(≥98%) Selective Trisubstituted Alkene Synthesis of Wide Applicability via Fluoride-Promoted Pd-Catalyzed Cross-Coupling of Alkenylboranes.

(Z)-ß-bromo-1-propenyl(pinacol)borane(4), recently made available in 85% yield as a ≥98% isomerically pure compound via bromoboration of 1-propyne, has been converted to ß-alkyl-, aryl-, and alkenyl-substituted (Z)-2-methyl-1-alkenyl(pinacol)boranes(2a) in ca. 75% yield based on propyne via Pd-catalyzed Negishi alkenylation with suitable organozinc bromide. The previously sluggish and modest-yielding Suzuki alkenylation of ß,ß-disubstituted alkenylboranes has been significantly promoted by fluorides, especially nBu4NF(TBAF) or CsF to give trisubstituted alkenes, i.e., (Z)-ß-Me-substituted 3-i-3-xi and (E)-ß-Ph-substituted 2b-i and 2b-ii. In all cases, each alkene product was formed in a ≥98% seteoselectivity. The propyne-based protocol nicely complements the widely used Zr-catalyzed alkyne methylalumination-Pd-catalyzed alkenylation by providing a highly stereoselective(≥98%) route to (Z)-Me-substituted alkenes.

Nonracemic diarylmethanols from CuH-catalyzed hydrosilylation of diaryl ketones.

An efficient method for the synthesis of nonracemic diarylmethanols has been developed. The use of ( R)-(-)-(DTBM-SEGPHOS)CuH effects highly enantioselective 1,2-hydrosilylation of prochiral diaryl ketones.

Asymmetric CuH-catalyzed hydrosilylations en route to the C-9 epimer of amphidinoketide iota.

The C-9 diastereomer of amphidinoketide I has been synthesized. An asymmetric CuH-catalyzed hydrosilylation based on the Solvias nonracemic Josiphos-related ligand (R,S)-PPF-P(t-Bu)2 was successfully used to introduce each of three stereocenters found in the target compound.

Chiral silanes via asymmetric hydrosilylation with catalytic CuH.

[reaction: see text] CuH-catalyzed asymmetric conjugate reduction of beta-silyl-alpha,beta-unsaturated esters has been developed. Using PMHS as a stoichiometric source of hydride and in situ generated CuH ligated by Solvias' JOSIPHOS analogue PPF-P(t-Bu)(2) leads to highly enantioselective 1,4-reductions.

Modulation of physical properties of Ter(9,9-ditolylfluorene) by backbone-embedded heteroarenes.

[structure: see text] Novel ter(9,9-ditolylfluorene) analogues containing thiophene and pyridine rings embedded as functional constituents within the parent hydrocarbon backbone have been synthesized. These new molecules exhibit highly efficient photoluminescence and high thermal and morphological stability. The electronic structure of the terfluorene backbone is significantly perturbed, which allows modulation of the backbone energy levels.

Serum- and glucocorticoid-inducible kinase (SGK) is a target of the MAPK/ERK signaling pathway that mediates memory formation in rats.

We have previously demonstrated that serum- and glucocorticoid-inducible kinase (SGK) plays a causal role in facilitating memory formation of spatial learning in rats, but the SGK signaling pathway involved in spatial memory formation is not known. The mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) also plays an important role in memory formation. We therefore examined whether SGK is a downstream target of the MAPK/ERK signaling cascade and whether ERK signaling to SGK mediates spatial memory formation in rats. Results from an in vitro kinase assay revealed that ERK directly phosphorylates SGK at Ser78, but not at Thr256 and Ser422, whereas inhibition of ERK by PD98059 significantly decreased SGK phosphorylation at Ser78, Thr256 and Ser422 following spatial training. Prior administration of PD98059 also antagonized the enhancing effect of 12-O-tetradecanoylphorbol-13-acetate (TPA), a protein kinase C activator that also causes ERK activation, on SGK phosphorylation and cAMP response element binding protein (CREB) phosphorylation. Moreover, TPA-induced SGK phosphorylation and CREB phosphorylation was abolished by prior SGKS78A mutant DNA transfection. By contrast, SGKS78A mutant DNA transfection to hippocampal area CA1 did not affect spatial memory formation, whereas SGKT256A mutant DNA transfection to area CA1 significantly impaired spatial memory formation. ERK was known to regulate sgk mRNA expression, but in the present study we have demonstrated that SGK is also a downstream target of the ERK signaling cascade; ERK directly phosphorylates SGK at Ser78 and indirectly activates SGK at Thr256 and Ser422 through unknown intermediate molecules. Furthermore, ERK activation of SGK is involved in spatial memory formation in rats.

Microwave-assisted heterogeneous cross-coupling reactions catalyzed by nickel-in-charcoal (Ni/C).

A study involving the relatively rare combination of heterogeneous catalysis conducted under microwave conditions is presented. Carbon-carbon bond formation, including Negishi and Suzuki couplings, can be quickly effected with aryl chloride partners by using a base metal (nickel) adsorbed in the pores of activated charcoal. Aminations were also studied, along with cross-couplings of vinyl alanes with benzylic chlorides as a means to stereodefined allylated aromatics. Reaction times for all these processes are typically reduced from several hours to minutes in a microwave reactor.