Developing a Tanshinone IIA Memetic by Targeting MIOS to Regulate mTORC1 and Autophagy in Glioblastoma.

Tanshinone IIA (T2A) is a bioactive compound that provides promise in the treatment of glioblastoma multiforme (GBM), with a range of molecular mechanisms including the inhibition of the mechanistic target of rapamycin complex 1 (mTORC1) and the induction of autophagy. Recently, T2A has been demonstrated to function through sestrin 2 (SESN) to inhibit mTORC1 activity, but its possible impact on autophagy through this pathway has not been investigated. Here, the model system and GBM cell lines were employed to investigate the cellular role of T2A in regulating SESN to inhibit mTORC1 and activate autophagy through a GATOR2 component MIOS.

Enhanced Sestrin expression through Tanshinone 2A treatment improves PI3K-dependent inhibition of glioma growth.

Glioblastomas are a highly aggressive cancer type which respond poorly to current pharmaceutical treatments, thus novel therapeutic approaches need to be investigated. One such approach involves the use of the bioactive natural product Tanshinone IIA (T2A) derived from the Chinese herb Danshen, where mechanistic insight for this anti-cancer agent is needed to validate its use. Here, we employ a tractable model system, Dictyostelium discoideum, to provide this insight.

Gamma secretase orthologs are required for lysosomal activity and autophagic degradation in , independent of PSEN (presenilin) proteolytic function.

Mutations in the γ-secretase complex are strongly associated with familial Alzheimer disease. Both proteolytic and non-proteolytic functions for the γ-secretase complex have been previously described in mammalian model organisms, but their relative contributions to disease pathology remain unclear. Here, we dissect the roles of orthologs of the γ-secretase components in the model system , focusing on endocytosis, lysosomal activity and autophagy.

Genetically Induced Retrograde Amnesia of Associative Memories After Neuroplastin Ablation.

Background: Neuroplastin cell recognition molecules have been implicated in synaptic plasticity. Polymorphisms in the regulatory region of the human neuroplastin gene (NPTN) are correlated with cortical thickness and intellectual abilities in adolescents and in individuals with schizophrenia.

Methods: We characterized behavioral and functional changes in inducible conditional neuroplastin-deficient mice.

The neuroplastins: multifunctional neuronal adhesion molecules--involvement in behaviour and disease.

The neuroplastins np65 and np55 are neuronal and synapse-enriched immunoglobulin (Ig) superfamily cell adhesion molecules that contain 3 and 2 Ig domains, respectively. Np65 is neuron specific whereas np55 is expressed in many tissues. They are multifunctional proteins whose physiological roles are defined by the partner proteins they bind to and the signalling pathways they activate.

The Neuroplastin adhesion molecules: key regulators of neuronal plasticity and synaptic function.

The Neuroplastins Np65 and Np55 are neuronal and synapse-enriched immunoglobulin superfamily molecules that play important roles in a number of key neuronal and synaptic functions including, for Np65, cell adhesion. In this review we focus on the physiological roles of the Neuroplastins in promoting neurite outgrowth, regulating the structure and function of both inhibitory and excitatory synapses in brain, and in neuronal and synaptic plasticity. We discuss the underlying molecular and cellular mechanisms by which the Neuroplastins exert their physiological effects and how these are dependent upon the structural features of Np65 and Np55, which enable them to bind to a diverse range of protein partners.

Structure of excitatory synapses and GABAA receptor localization at inhibitory synapses are regulated by neuroplastin-65.

Formation, maintenance, and activity of excitatory and inhibitory synapses are essential for neuronal network function. Cell adhesion molecules (CAMs) are crucially involved in these processes. The CAM neuroplastin-65 (Np65) highly expressed during periods of synapse formation and stabilization is present at the pre- and postsynaptic membranes.

An ancestral non-proteolytic role for presenilin proteins in multicellular development of the social amoeba Dictyostelium discoideum.

Mutations in either of two presenilin genes can cause familial Alzheimer's disease. Presenilins have both proteolysis-dependent functions, as components of the γ-secretase complex, and proteolysis-independent functions in signalling. In this study, we investigate a conserved function of human presenilins in the development of the simple model organism Dictyostelium discoideum.

The neuroplastin adhesion molecules are accessory proteins that chaperone the monocarboxylate transporter MCT2 to the neuronal cell surface.

Background: The neuroplastins np65 and np55 are two synapse-enriched immunoglobulin (Ig) superfamily adhesion molecules that contain 3 and 2 Ig domains respectively. Np65 is implicated in long term, activity dependent synaptic plasticity, including LTP. Np65 regulates the surface expression of GluR1 receptor subunits and the localisation of GABA(A) receptor subtypes in hippocampal neurones.

Amyloid-β acts as a regulator of neurotransmitter release disrupting the interaction between synaptophysin and VAMP2.

Background: It is becoming increasingly evident that deficits in the cortex and hippocampus at early stages of dementia in Alzheimer's disease (AD) are associated with synaptic damage caused by oligomers of the toxic amyloid-β peptide (Aβ42). However, the underlying molecular and cellular mechanisms behind these deficits are not fully understood. Here we provide evidence of a mechanism by which Aβ42 affects synaptic transmission regulating neurotransmitter release.

Lobe-specific functions of Ca2+·calmodulin in alphaCa2+·calmodulin-dependent protein kinase II activation.

N-methyl-D-aspartic acid receptor-dependent long term potentiation (LTP), a model of memory formation, requires Ca2+·calmodulin-dependent protein kinase II (αCaMKII) activity and Thr286 autophosphorylation via both global and local Ca2+ signaling, but the mechanisms of signal transduction are not understood. We tested the hypothesis that the Ca2+-binding activator protein calmodulin (CaM) is the primary decoder of Ca2+ signals, thereby determining the output, e.g.

Marine biodiversity in the Australian region.

The entire Australian marine jurisdictional area, including offshore and sub-Antarctic islands, is considered in this paper. Most records, however, come from the Exclusive Economic Zone (EEZ) around the continent of Australia itself. The counts of species have been obtained from four primary databases (the Australian Faunal Directory, Codes for Australian Aquatic Biota, Online Zoological Collections of Australian Museums, and the Australian node of the Ocean Biogeographic Information System), but even these are an underestimate of described species.

Reduced expression of the Ca(2+) transporter protein PMCA2 slows Ca(2+) dynamics in mouse cerebellar Purkinje neurones and alters the precision of motor coordination.

Cerebellar Purkinje neurones (PNs) express high levels of the plasma membrane calcium ATPase, PMCA2, a transporter protein critical for the clearance of calcium from excitable cells. Genetic deletion of one PMCA2 encoding gene in heterozygous PMCA2 knock-out (PMCA2(+/-) mice enabled us to determine how PMCA2 influences PN calcium regulation without the complication of the severe morphological changes associated with complete PMCA2 knock-out (PMCA2(-/-) in these cells. The PMCA2(+/-) cerebellum expressed half the normal levels of PMCA2 and this nearly doubled the time taken for PN dendritic calcium transients to recover (mean fast and slow recovery times increased from 70 ms to 110 ms and from 600 ms to 1100 ms).

Evidence for a homodimeric structure of human monocarboxylate transporter 8.

The human monocarboxylate transporter 8 (hMCT8) protein mediates transport of thyroid hormone across the plasma membrane. Association of hMCT8 mutations with severe psychomotor retardation and disturbed thyroid hormone levels has established its physiological relevance, but little is still known about the basic properties of hMCT8. In this study we present evidence that hMCT8 does not form heterodimers with the ancillary proteins basigin, embigin, or neuroplastin, unlike other MCTs.

Molecular interactions of the plasma membrane calcium ATPase 2 at pre- and post-synaptic sites in rat cerebellum.

The plasma membrane calcium extrusion mechanism, PMCA (plasma membrane calcium ATPase) isoform 2 is richly expressed in the brain and particularly the cerebellum. Whilst PMCA2 is known to interact with a variety of proteins to participate in important signalling events [Strehler EE, Filoteo AG, Penniston JT, Caride AJ (2007) Plasma-membrane Ca(2+) pumps: structural diversity as the basis for functional versatility. Biochem Soc Trans 35 (Pt 5):919-922], its molecular interactions in brain synapse tissue are not well understood.

Identification of novel tumor antigens with patient-derived immune-selected antibodies.

The identification of tumor antigens capable of eliciting an immune response in vivo may be an effective method to identify therapeutic cancer targets. We have developed a method to identify such antigens using frozen tumor-draining lymph node samples from breast cancer patients. Immune responses in tumor-draining lymph nodes were identified by immunostaining lymph node sections for B-cell markers (CD20&CD23) and Ki67 which revealed cell proliferation in germinal center zones.

Coelomic expression of a novel bone morphogenetic protein in regenerating arms of the brittle star Amphiura filiformis.

The bone morphogenetic proteins (BMPs) are a family of signalling molecules involved in numerous developmental processes including cell fate determination in embryonic ectoderm of vertebrate and invertebrate species. Recently, published evidence has indicated that BMPs are involved in echinoderm adult tissue regeneration. We have cloned a novel member of the BMP2/4 subfamily from the ophiuroid echinoderm Amphiura filiformis, which we have named afBMP2/4.

SGCE missense mutations that cause myoclonus-dystonia syndrome impair epsilon-sarcoglycan trafficking to the plasma membrane: modulation by ubiquitination and torsinA.

Myoclonus-dystonia syndrome (MDS) is a genetically heterogeneous disorder characterized by myoclonic jerks often seen in combination with dystonia and psychiatric co-morbidities and epilepsy. Mutations in the gene encoding epsilon-sarcoglycan (SGCE) have been found in some patients with MDS. SGCE is a maternally imprinted gene with the disease being inherited in an autosomal dominant pattern with reduced penetrance upon maternal transmission.

The immunolocalization of the synaptic glycoprotein neuroplastin differs substantially between the human and the rodent brain.

Neuroplastin is a cell adhesion molecule of the immunoglobulin superfamily that exists in two splice isoforms, np65/np55, and that was reported to play a prominent role in synaptic plasticity processes. The splice isoform np65 associates with synapses in an activity-dependent manner and has been shown to play a role for the induction of hippocampal long-term potentiation in rodents. We have therefore analyzed the distribution of neuroplastins in human brain.

The cell adhesion molecule neuroplastin-65 inhibits hippocampal long-term potentiation via a mitogen-activated protein kinase p38-dependent reduction in surface expression of GluR1-containing glutamate receptors.

Neuroplastin-65 is a brain-specific, synapse-enriched member of the immunoglobulin (Ig) superfamily of cell adhesion molecules. Previous studies highlighted the importance of neuroplastin-65 for long-term potentiation (LTP), but the mechanism was unclear. Here, we show how neuroplastin-65 activation of mitogen-activated protein kinase p38 (p38MAPK) modified synapse strength by altering surface glutamate receptor expression.

Afuni, a novel transforming growth factor-beta gene is involved in arm regeneration by the brittle star Amphiura filiformis.

The bone morphogenetic proteins (BMPs) are a family of the transforming growth factor-beta (TGF-beta) superfamily that perform multiple roles during vertebrate and invertebrate development. Here, we report the molecular cloning of a novel BMP from regenerating arms of the ophiuroid Amphiura filiformis. The theoretically translated amino acid sequence of this novel BMP has high similarity to that of the sea urchin BMP univin.

Comparison of neuroplastin and synaptic marker protein expression in acute and cultured organotypic hippocampal slices from rat.

Organotypic hippocampal slice cultures can be used to study hippocampal biochemistry and physiology over a chronic period on the days to weeks timescale. In order to validate the organotypic hippocampal slice culture for our ongoing studies of synaptic function, we have compared, using Western blotting, the levels of a number of synaptic proteins from in vitro organotypic hippocampal slice cultures with those from in vivo hippocampal slices prepared from age-matched controls. We chose to follow the developmental expression of the neuroplastin (np) family of immunoglobulin related cell adhesion molecules (CAMs), np65, a brain specific isoform highly expressed in hippocampal neurones and np55 a more widely expressed isoform and two synaptic marker proteins, synaptophysin, a pre-synaptic marker and post-synaptic density protein-95, PSD95, a post-synaptic marker.

Changes in ubiquitin conjugates and Hsp72 levels during arm regeneration in echinoderms.

All organisms show a common defensive mechanism that results in the expression of conserved heat shock proteins (Hsps). These proteins function in a wide range of stressful conditions. We have monitored their levels in species of regenerating echinoderms with different mechanisms of regeneration and from different geographical locations.

Anbmp2/4 is a new member of the transforming growth factor-beta superfamily isolated from a crinoid and involved in regeneration.

Invertebrates have frequently been used to help understand the complexities of regulatory gene function and evolution. The bone morphogenetic proteins (BMPs) are a highly conserved group of secreted regulatory factors that play an important part in early embryonic patterning. In the present study we have used the remarkable regenerative potential of crinoid echinoderms to explore the BMPs' site of expression in an adult developmental programme.