Identification of distinct conformations associated with monomers and fibril assemblies of mutant huntingtin.

The N-terminal fragments of mutant huntingtin (mHTT) misfold and assemble into oligomers, which ultimately bundle into insoluble fibrils. Conformations unique to various assemblies of mHTT remain unknown. Knowledge on the half-life of various multimeric structures of mHTT is also scarce.

IKKβ and mutant huntingtin interactions regulate the expression of IL-34: implications for microglial-mediated neurodegeneration in HD.

Neuronal interleukin-34 (IL-34) promotes the expansion of microglia in the central nervous system-microglial activation and expansion are in turn implicated in the pathogenesis of Huntington's disease (HD). We thus examined whether the accumulation of an amyloidogenic exon-1 fragment of mutant huntingtin (mHTTx1) modulates the expression of IL-34 in dopaminergic neurons derived from a human embryonic stem cell line. We found that mHTTx1 aggregates induce IL-34 production selectively in post-mitotic neurons.

Antibodies and intrabodies against huntingtin: production and screening of monoclonals and single-chain recombinant forms.

Antibodies can be extremely useful tools for the field of triplet repeats diseases. These reagents are important for localizing proteins in tissues and they can be used in the isolation and characterization of the components of protein complexes. In the context of huntingtin (Htt), antibodies can distinguish Htt with normal or an expanded polyglutamine (polyQ) repeats, and they can identify distinct conformations of Htt.

Intrabody gene therapy ameliorates motor, cognitive, and neuropathological symptoms in multiple mouse models of Huntington's disease.

Huntington's disease (HD) is an autosomal dominant neurodegenerative disease resulting from the expansion of a glutamine repeat in the huntingtin (Htt) protein. Current therapies are directed at managing symptoms such as chorea and psychiatric disturbances. In an effort to develop a therapy directed at disease prevention we investigated the utility of highly specific, anti-Htt intracellular antibodies (intrabodies).

Monoclonal antibodies recognize distinct conformational epitopes formed by polyglutamine in a mutant huntingtin fragment.

Huntington disease (HD) is a neurodegenerative disorder caused by an expansion of a polyglutamine (polyQ) domain in the N-terminal region of huntingtin (htt). PolyQ expansion above 35-40 results in disease associated with htt aggregation into inclusion bodies. It has been hypothesized that expanded polyQ domains adopt multiple potentially toxic conformations that belong to different aggregation pathways.

IKKalpha and IKKbeta regulation of DNA damage-induced cleavage of huntingtin.

Background: Proteolysis of huntingtin (Htt) plays a key role in the pathogenesis of Huntington's disease (HD). However, the environmental cues and signaling pathways that regulate Htt proteolysis are poorly understood. One stimulus may be the DNA damage that accumulates in neurons over time, and the subsequent activation of signaling pathways such as those regulated by IkappaB kinase (IKK), which can influence neurodegeneration in HD.

Structures of Abeta-related peptide--monoclonal antibody complexes.

Passive immunotherapy (PI) is being explored as a potential therapeutic against Alzheimer's disease. The most promising antibodies (Abs) used in PI target the EFRH motif of the Abeta N-terminus. The monoclonal anti-Abeta Ab PFA1 recognizes the EFRH epitope of Abeta.

Activation of the IkappaB kinase complex and nuclear factor-kappaB contributes to mutant huntingtin neurotoxicity.

Transcriptional dysregulation by mutant huntingtin (Htt) protein has been implicated in the pathogenesis of Huntington's disease (HD). We find that cultured cells expressing mutant Htt and striatal cells from HD transgenic mice have elevated nuclear factor-kappaB (NF-kappaB) activity. Furthermore, NF-kappaB is concentrated in the nucleus of neurons in the brains of HD transgenic mice.

Antibodies against huntingtin: production and screening of monoclonals and single-chain recombinant forms.

Antibodies can be extremely useful tools for the field of triplet repeat diseases. These reagents are important for localizing proteins in tissues, and within cells, they can be used in the isolation and characterization of the components of protein complexes, they can distinguish proteins with normal or an expanded polyglutamine repeat, they may be able to distinguish distinct conformations of a protein, and they can be used to perturb the function of proteins in living cells. Our group has produced monoclonal and recombinant single-chain antibodies that can be used for each of these purposes with huntingtin.

Neonatal impact of leukemia inhibitory factor on neurobehavioral development in rats.

Cytokines have been implicated in the etiology or pathology of various psychiatric diseases of developmental origin such as autism and schizophrenia. Leukemia inhibitory factor (LIF) is induced by a variety of brain insults and known to have many influences on mature and immature nervous system. Here, we assessed the neurobehavioral and pathological consequences of peripheral administration of LIF in newborn rats.

Effects of intracellular expression of anti-huntingtin antibodies of various specificities on mutant huntingtin aggregation and toxicity.

We have generated eight mAbs (MW1-8) that bind the epitopes polyglutamine (polyQ), polyproline (polyP), or the C terminus of exon 1 in huntingtin (htt) protein. In the brains of Huntington's disease (HD) mouse models, the anti-polyQ mAbs bind to various cytoplasmic compartments, whereas the anti-polyP and anti-C terminus mAbs bind nuclear inclusions containing htt. To use these mAbs as intracellular perturbation agents, we have cloned and expressed the antigen-binding domains of three of the mAbs as single-chain variable region fragment Abs (scFvs).