Chondroitin Sulfate-Coated Heteroduplex-Molecular Spherical Nucleic Acids.

Molecular Spherical Nucleic Acids (MSNAs) are atomically uniform dendritic nanostructures and potential delivery vehicles for oligonucleotides. The radial formulation combined with covalent conjugation may hide the oligonucleotide content and simultaneously enhance the role of appropriate conjugate groups on the outer sphere. The conjugate halo may be modulated to affect the delivery properties of the MSNAs.

SHANK3 conformation regulates direct actin binding and crosstalk with Rap1 signaling.

Actin-rich cellular protrusions direct versatile biological processes from cancer cell invasion to dendritic spine development. The stability, morphology, and specific biological functions of these protrusions are regulated by crosstalk between three main signaling axes: integrins, actin regulators, and small guanosine triphosphatases (GTPases). SHANK3 is a multifunctional scaffold protein, interacting with several actin-binding proteins and a well-established autism risk gene.

Protein synthesis is suppressed in sporadic and familial Parkinson's disease by LRRK2.

Gain of function LRRK2-G2019S is the most frequent mutation found in familial and sporadic Parkinson's disease. It is expected therefore that understanding the cellular function of LRRK2 will provide insight on the pathological mechanism not only of inherited Parkinson's, but also of sporadic Parkinson's, the more common form. Here, we show that constitutive LRRK2 activity controls nascent protein synthesis in rodent neurons.

PIM1 accelerates prostate cancer cell motility by phosphorylating actin capping proteins.

Background: The PIM family kinases promote cancer cell survival and motility as well as metastatic growth in various types of cancer. We have previously identified several PIM substrates, which support cancer cell migration and invasiveness. However, none of them are known to regulate cellular movements by directly interacting with the actin cytoskeleton.

Impact of JNK and Its Substrates on Dendritic Spine Morphology.

The protein kinase JNK1 exhibits high activity in the developing brain, where it regulates dendrite morphology through the phosphorylation of cytoskeletal regulatory proteins. JNK1 also phosphorylates dendritic spine proteins, and mice display a long-term depression deficit. Whether JNK1 or other JNKs regulate spine morphology is thus of interest.

Optogenetic Control of Spine-Head JNK Reveals a Role in Dendritic Spine Regression.

In this study, we use an optogenetic inhibitor of c-Jun NH-terminal kinase (JNK) in dendritic spine sub-compartments of rat hippocampal neurons. We show that JNK inhibition exerts rapid (within seconds) reorganization of actin in the spine-head. Using real-time Förster resonance energy transfer (FRET) to measure JNK activity, we find that either excitotoxic insult (NMDA) or endocrine stress (corticosterone), activate spine-head JNK causing internalization of AMPARs and spine retraction.

JNK Regulation of Depression and Anxiety.

Depression and anxiety are the most common mood disorders affecting 300 million sufferers worldwide. Maladaptive changes in the neuroendocrine stress response is cited as the most common underlying cause, though how the circuits underlying this response are controlled at the molecular level, remains largely unknown. Approximately 40% of patients do not respond to current treatments, indicating that untapped mechanisms exist.

Repositioning Microtubule Stabilizing Drugs for Brain Disorders.

Microtubule stabilizing agents are among the most clinically useful chemotherapeutic drugs. Mostly, they act to stabilize microtubules and inhibit cell division. While not without side effects, new generations of these compounds display improved pharmacokinetic properties and brain penetrance.

Synthesis of Azide-Modified Chondroitin Sulfate Precursors: Substrates for "Click"- Conjugation with Fluorescent Labels and Oligonucleotides.

Azidopropyl-modified precursors of chondroitin sulfate (CS) tetrasaccharides have been synthesized, which, after facile conversion to final CS structures, may be conjugated with alkyne-modified target compounds by a one-pot "click"-ligation. RP HPLC was used for the monitoring of the key reaction steps (protecting group manipulation and sulfation) and purification of the CS precursors (as partially protected form, bearing the O-Lev, O-benzoyl, and N-trichloroacetyl groups and methyl esters). Subsequent treatments with aqueous NaOH, concentrated ammonia, and acetic anhydride (i.

Microtubule and microtubule associated protein anomalies in psychiatric disease.

Anomalies in neuronal cell architecture, in particular dendritic complexity and synaptic density changes, are widely observed in the brains of subjects with schizophrenia or mood disorders. The concept that a disturbed microtubule cytoskeleton underlies these abnormalities and disrupts synaptic connectivity is supported by evidence from clinical studies and animal models. Prominent changes in tubulin expression levels are commonly found in disease specific regions such as the hippocampus and prefrontal cortex of psychiatric patients.

KIF5C S176 Phosphorylation Regulates Microtubule Binding and Transport Efficiency in Mammalian Neurons.

Increased phosphorylation of the KIF5 anterograde motor is associated with impaired axonal transport and neurodegeneration, but paradoxically also with normal transport, though the details are not fully defined. JNK phosphorylates KIF5C on S176 in the motor domain; a site that we show is phosphorylated in brain. Microtubule pelleting assays demonstrate that phosphomimetic KIF5C(1-560)(S176D) associates weakly with microtubules compared to KIF5C(1-560)(WT).

CANDLES, an assay for monitoring GPCR induced cAMP generation in cell cultures.

Background: G protein-coupled receptors (GPCRs) represent a physiologically and pharmacologically important family of receptors that upon coupling to GαS stimulate cAMP production catalyzed by adenylyl cyclase. Thus, developing assays to monitor cAMP production is crucial to screen for ligands in studies of GPCR signaling. Primary cell cultures represent a more robust model than cell lines to study GPCR signaling since they physiologically resemble the parent tissue.

JNK1 controls dendritic field size in L2/3 and L5 of the motor cortex, constrains soma size, and influences fine motor coordination.

Genetic anomalies on the JNK pathway confer susceptibility to autism spectrum disorders, schizophrenia, and intellectual disability. The mechanism whereby a gain or loss of function in JNK signaling predisposes to these prevalent dendrite disorders, with associated motor dysfunction, remains unclear. Here we find that JNK1 regulates the dendritic field of L2/3 and L5 pyramidal neurons of the mouse motor cortex (M1), the main excitatory pathway controlling voluntary movement.

Nuclear and cytosolic JNK signalling in neurons.

It has been over 20 years since JUN amino-terminal kinases (JNKs) were identified as protein kinases that are strongly activated by cellular stress and that have a key role in apoptosis. Examination of Jnk-knockout mice and characterization of JNK behaviour in neuronal cells has further revealed the importance of the JNK family in the nervous system. As well as regulating neuronal death, JNKs govern brain morphogenesis and axodendritic architecture during development, and regulate important neuron-specific functions such as synaptic plasticity and memory formation.

The impact of JNK on neuronal migration.

Incorrect placement of nerve cells during brain development leaves us at risk of diseases and conditions ranging from epilepsy and mental retardation to schizophrenia and dyslexia. The developing brain produces cells at an impressive rate, with up to 250,000 new cells generated every minute. These newborn cells migrate long distances in sequential waves to settle in the layers that make up the cerebral cortex.

Translocation of Vibrio parahaemolyticus across an in vitro M cell model.

Consumption of Vibrio parahaemolyticus via contaminated shellfish results in inflammatory gastroenteritis characterised by severe diarrhoea, nausea and stomach cramps. This study investigated the translocation of V. parahaemolyticus across a Peyer's patch M cell-like Caco-2/Raji B co-culture model system, as M cells represent a primary site of infection for many pathogenic bacteria.

The prognostic value of MARCKS-like 1 in lymph node-negative breast cancer.

There is a need for new biomarkers to more correctly identify node-negative breast cancer patients with a good or bad prognosis. Myristoylated alanine-rich C kinase substrate like-1 (MARCKSL1) is a membrane-bound protein that is associated with cell spreading, integrin activation and exocytosis. Three hundred and five operable T(1,2)N(0)M(0) lymph node-negative breast cancer patients (median follow-up time 121 months, range 10-178 months) were evaluated for MARCKSL1 expression by immunohistochemistry and quantitative real-time PCR.

c-Jun N-terminal kinase phosphorylation of MARCKSL1 determines actin stability and migration in neurons and in cancer cells.

Cell migration is a fundamental biological function, critical during development and regeneration, whereas deregulated migration underlies neurological birth defects and cancer metastasis. MARCKS-like protein 1 (MARCKSL1) is widely expressed in nervous tissue, where, like Jun N-terminal protein kinase (JNK), it is required for neural tube formation, though the mechanism is unknown. Here we show that MARCKSL1 is directly phosphorylated by JNK on C-terminal residues (S120, T148, and T183).

Phosphorylation of SCG10/stathmin-2 determines multipolar stage exit and neuronal migration rate.

Cell migration is the consequence of the sum of positive and negative regulatory mechanisms. Although appropriate migration of neurons is a principal feature of brain development, the negative regulatory mechanisms remain obscure. We found that JNK1 was highly active in developing cortex and that selective inhibition of JNK in the cytoplasm markedly increased both the frequency of exit from the multipolar stage and radial migration rate and ultimately led to an ill-defined cellular organization.

The Vibrio parahaemolyticus Type III Secretion Systems manipulate host cell MAPK for critical steps in pathogenesis.

Background: Vibrio parahaemolyticus is a food-borne pathogen causing inflammation of the gastrointestinal epithelium. Pathogenic strains of this bacterium possess two Type III Secretion Systems (TTSS) that deliver effector proteins into host cells. In order to better understand human host cell responses to V.

AMPAR signaling mediating GABA(A)R delta subunit up-regulation in cultured mouse cerebellar granule cells.

Depolarization of cerebellar granule cells in culture leads to up-regulation of the GABA(A) receptor delta subunit expression. To determine the signaling molecules involved, we examined the effects of protein kinase inhibitors and cyclic AMP-elevating compounds on basal and AMPAR agonist-induced delta mRNA expression in cerebellar granule cells. Treatment with the c-Jun N-terminal kinase (JNK) inhibitor SP600125 or with pituitary adenylate activating polypeptide increased delta subunit expression by 70%.

Microtubule stabilization by bone morphogenetic protein receptor-mediated scaffolding of c-Jun N-terminal kinase promotes dendrite formation.

Neuronal outgrowth occurs via coordinated remodeling of the cytoskeleton involving both actin and microtubules. Microtubule stabilization drives the extending neurite, yet little is known of the molecular mechanisms whereby extracellular cues regulate microtubule dynamics. Bone morphogenetic proteins (BMPs) play an important role in neuronal differentiation and morphogenesis, and BMP7 in particular induces the formation of dendrites.

Pathogenic huntingtin inhibits fast axonal transport by activating JNK3 and phosphorylating kinesin.

Selected vulnerability of neurons in Huntington's disease suggests that alterations occur in a cellular process that is particularly critical for neuronal function. Supporting this idea, pathogenic Htt (polyQ-Htt) inhibits fast axonal transport (FAT) in various cellular and animal models of Huntington's disease (mouse and squid), but the molecular basis of this effect remains unknown. We found that polyQ-Htt inhibited FAT through a mechanism involving activation of axonal cJun N-terminal kinase (JNK).

Concurrent protective and destructive signaling of JNK2 in neuroblastoma cells.

Investigation of the c-Jun N-terminal kinases (JNKs) has mainly focused on their response to stress and their pro-apoptotic effects. In this regard, JNKs are crucial mediators of chemotherapy-induced killing of tumor cells. Importantly, however, JNKs also have physiological functions in cancer involving cell cycle regulation or oncogenesis.

Loss-of-function of IKAP/ELP1: could neuronal migration defect underlie familial dysautonomia?

Familial dysautonomia (FD) is a hereditary neuronal disease characterized by poor development and progressive degeneration of the sensory and autonomic nervous system. Majority of FD (99.5%) results from a single nucleotide point mutation in the IKBKAP gene encoding IKAP, also known as elongation protein 1 (ELP1).