Mannose-coupled AAV2: A second-generation AAV vector for increased retinal gene therapy efficiency.

Inherited retinal diseases are a leading and untreatable cause of blindness and are therefore candidate diseases for gene therapy. Recombinant vectors derived from adeno-associated virus (rAAV) are currently the most promising vehicles for therapeutic gene delivery to the retina. However, there is a need for novel AAV-based vectors with greater efficacy for ophthalmic applications, as underscored by recent reports of dose-related inflammatory responses in clinical trials of rAAV-based ocular gene therapies.

Insulin receptor activation by proinsulin preserves synapses and vision in retinitis pigmentosa.

Synaptic loss, neuronal death, and circuit remodeling are common features of central nervous system neurodegenerative disorders. Retinitis pigmentosa (RP), the leading cause of inherited blindness, is a group of retinal dystrophies characterized by photoreceptor dysfunction and death. The insulin receptor, a key controller of metabolism, also regulates neuronal survival and synaptic formation, maintenance, and activity.

Outer Plexiform Layer Structures Are Not Altered Following AAV-Mediated Gene Transfer in Healthy Rat Retina.

Ocular gene therapy approaches have been developed for a variety of different diseases. In particular, clinical gene therapy trials for RPE65 mutations, X-linked retinoschisis, and choroideremia have been conducted at different centers in recent years, showing that adeno-associated virus (AAV)-mediated gene therapy is safe, but limitations exist as to the therapeutic benefit and long-term duration of the treatment. The technique of vector delivery to retinal cells relies on subretinal injection of the vector solution, causing a transient retinal detachment.

Intravitreal Injection of Proinsulin-Loaded Microspheres Delays Photoreceptor Cell Death and Vision Loss in the rd10 Mouse Model of Retinitis Pigmentosa.

Purpose: The induction of proinsulin expression by transgenesis or intramuscular gene therapy has been shown previously to retard retinal degeneration in mouse and rat models of retinitis pigmentosa (RP), a group of inherited conditions that result in visual impairment. We investigated whether intraocular treatment with biodegradable poly (lactic-co-glycolic) acid microspheres (PLGA-MS) loaded with proinsulin has cellular and functional neuroprotective effects in the retina.

Methods: Experiments were performed using the Pde6brd10 mouse model of RP.

Proinsulin slows retinal degeneration and vision loss in the P23H rat model of retinitis pigmentosa.

Proinsulin has been characterized as a neuroprotective molecule. In this work we assess the therapeutic potential of proinsulin on photoreceptor degeneration, synaptic connectivity, and functional activity of the retina in the transgenic P23H rat, an animal model of autosomal dominant retinitis pigmentosa (RP). P23H homozygous rats received an intramuscular injection of an adeno-associated viral vector serotype 1 (AAV1) expressing human proinsulin (hPi+) or AAV1-null vector (hPi-) at P20.

Mouse model of OPRM1 (A118G) polymorphism has sex-specific effects on drug-mediated behavior.

A single nucleotide polymorphism (SNP) in the human mu-opioid receptor gene (OPRM1 A118G) has been widely studied for its association in a variety of drug addiction and pain sensitivity phenotypes; however, the extent of these adaptations and the mechanisms underlying these associations remain elusive. To clarify the functional mechanisms linking the OPRM1 A118G SNP to addiction and analgesia phenotypes, we derived a mouse model possessing the equivalent nucleotide/amino acid substitution in the Oprm1 gene. Mice harboring this SNP (A112G) demonstrated several phenotypic similarities to humans carrying the A118G SNP, including reduced mRNA expression and morphine-mediated antinociception.

Sex differences in response to nicotine in C57Bl/6:129SvEv mice.

Introduction: Human studies suggest that smoking behavior in men may depend more on the pharmacological effects of nicotine, whereas in women, this behavior may rely more on nonpharmacological factors associated with smoking. Investigation of these parameters in mice may also reveal sex differences.

Methods: Male and female C57Bl/6:129SvEv hybrid mice were exposed to increasing concentrations of nicotine in a voluntary oral nicotine consumption paradigm in which we measured fluid consumption over time and dose.

Enhancement of presynaptic glutamate release and persistent inflammatory pain by increasing neuronal cAMP in the anterior cingulate cortex.

Both presynaptic and postsynaptic alterations are associated with plastic changes of brain circuits, such as learning and memory, drug addiction and chronic pain. However, the dissection of the relative contributions of pre- and postsynaptic components to brain functions is difficult. We have previously shown peripheral inflammation caused both presynaptic and postsynaptic changes and calcium-stimulated cyclic AMP (cAMP) pathway in the anterior cingulate cortex (ACC) is critical in the synaptic plasticity and behavioral sensitization to pain.

A novel conditional genetic system reveals that increasing neuronal cAMP enhances memory and retrieval.

Consistent evidence from pharmacological and genetic studies shows that cAMP is a critical modulator of synaptic plasticity and memory formation. However, the potential of the cAMP signaling pathway as a target for memory enhancement remains unclear because of contradictory findings from pharmacological and genetic approaches. To address these issues, we have developed a novel conditional genetic system in mice based on the heterologous expression of an Aplysia octopamine receptor, a G-protein-coupled receptor whose activation by its natural ligand octopamine leads to rapid and transient increases in cAMP.

Transgenic inhibition of neuronal protein kinase A activity facilitates fear extinction.

Much is known about the neurobiology of memory storage for learned fear. In contrast, the molecular mechanisms underlying extinction of fear memory are just beginning to be delineated. Here, we investigate the role of protein kinase A (PKA) in extinction of memory for contextual fear by using conventional and temporally regulated transgenic approaches that allow us to inhibit PKA activity in neurons within brain regions thought to be involved in extinction.

Constitutive activation of Galphas within forebrain neurons causes deficits in sensorimotor gating because of PKA-dependent decreases in cAMP.

Sensorimotor gating, the ability to automatically filter sensory information, is deficient in a number of psychiatric disorders, yet little is known of the biochemical mechanisms underlying this critical neural process. Previously, we reported that mice expressing a constitutively active isoform of the G-protein subunit Galphas (Galphas(*)) within forebrain neurons exhibit decreased gating, as measured by prepulse inhibition of acoustic startle (PPI). Here, to elucidate the biochemistry regulating sensorimotor gating and to identify novel therapeutic targets, we test the hypothesis that Galphas(*) causes PPI deficits via brain region-specific changes in cyclic AMP (cAMP) signaling.

Metaplasticity of the late-phase of long-term potentiation: a critical role for protein kinase A in synaptic tagging.

The late-phase of long-term potentiation (L-LTP) in hippocampal area CA1 requires gene expression and de novo protein synthesis but it is expressed in an input-specific manner. The 'synaptic tag' theory proposes that gene products can only be captured and utilized at synapses that have been 'tagged' by previous activity. The mechanisms underlying synaptic tagging, and its activity dependence, are largely undefined.

Differential transcriptional response to nonassociative and associative components of classical fear conditioning in the amygdala and hippocampus.

Classical fear conditioning requires the recognition of conditioned stimuli (CS) and the association of the CS with an aversive stimulus. We used Affymetrix oligonucleotide microarrays to characterize changes in gene expression compared to naive mice in both the amygdala and the hippocampus 30 min after classical fear conditioning and 30 min after exposure to the CS in the absence of an aversive stimulus. We found that in the hippocampus, levels of gene regulation induced by classical fear conditioning were not significantly greater than those induced by CS alone, whereas in the amygdala, classical fear conditioning did induce significantly greater levels of gene regulation compared to the CS.

Streptomyces lividans groES, groEL1 and groEL2 genes.

The Streptomyces lividans groES/EL1 operon and groEL2 gene were cloned and their respective DNA sequences determined. The sequenced DNA comprised the genes and their respective regulatory regions in both cases. Transcription of both groES/EL1 and groEL2 seemed to be subjected to temporal control at 30 degrees C.