TDP-43, an ALS linked protein, regulates fat deposition and glucose homeostasis.

The identification of proteins which determine fat and lean body mass composition is critical to better understanding and treating human obesity. TDP-43 is a well-conserved RNA-binding protein known to regulate alternative splicing and recently implicated in the pathogenesis of amyotrophic lateral sclerosis (ALS). While TDP-43 knockout mice show early embryonic lethality, post-natal conditional knockout mice show weight loss, fat depletion, and rapid death, suggesting an important role for TDP-43 in regulating energy metabolism.

Biochemical properties and in vivo effects of the SOD1 zinc-binding site mutant (H80G).

This study presents the initial characterization of transgenic mice with mutations in a primary zinc-binding residue (H80), either alone or with a G93A mutation. H80G;G93A superoxide dismutase 1 (SOD1) transgenic mice developed paralysis with motor neuron loss, and ubiquitin inclusion-type rather than mitochondrial vacuolar pathology. Unlike G93A SOD1-related disease, the course was not accelerated by over-expression of copper chaperone for SOD1.

Progressive motor weakness in transgenic mice expressing human TDP-43.

Familial ALS patients with TDP-43 gene mutations and sporadic ALS patients share common TDP-43 neuronal pathology. To delineate mechanisms underlying TDP-43 proteinopathies, transgenic mice expressing A315T, M337V or wild type human TDP-43 were generated. Multiple TDP-43 founders developed a severe early motor phenotype that correlated with TDP-43 levels in spinal cord.

Silencing Nogo-A promotes functional recovery in demyelinating disease.

Objective: To determine if suppressing Nogo-A, an axonal inhibitory protein, will promote functional recovery in a murine model of multiple sclerosis (MS).

Methods: A small interfering RNA was developed to specifically suppress Nogo-A (siRNA-NogoA). The siRNA-NogoA silencing effect was evaluated in vitro and in vivo via immunohistochemistry.

Pharmacological prion protein silencing accelerates central nervous system autoimmune disease via T cell receptor signalling.

The primary biological function of the endogenous cellular prion protein has remained unclear. We investigated its biological function in the generation of cellular immune responses using cellular prion protein gene-specific small interfering ribonucleic acid in vivo and in vitro. Our results were confirmed by blocking cellular prion protein with monovalent antibodies and by using cellular prion protein-deficient and -transgenic mice.

Redox susceptibility of SOD1 mutants is associated with the differential response to CCS over-expression in vivo.

Over-expression of CCS in G93A SOD1 mice accelerates neurological disease and enhances mitochondrial pathology. We studied the effect of CCS over-expression in transgenic mice expressing G37R, G86R or L126Z SOD1 mutations in order to understand factors which influence mitochondrial dysfunction. Over-expression of CCS markedly decreased survival and produced mitochondrial vacuolation in G37R SOD1 mice but not in G86R or L126Z SOD1 mice.

The death domain-containing kinase RIP1 regulates p27(Kip1) levels through the PI3K-Akt-forkhead pathway.

Elucidating the cross-talk between inflammatory and cell proliferation pathways might provide important insights into the pathogenesis of inflammation-induced cancer. Here, we show that the receptor-interacting protein 1 (RIP1)-an essential mediator of inflammation-induced nuclear factor-kappaB (NF-kappaB) activation-regulates p27(Kip1) levels and cell-cycle progression. RIP1 regulates p27(Kip1) levels by an NF-kappaB-independent signal that involves activation of the phosphatidylinositol 3-kinase (PI3K)-Akt-forkhead pathway.

Assessing the role of immuno-proteasomes in a mouse model of familial ALS.

The accumulation of protein aggregates is thought to be an important component in the pathogenesis of mutant SOD1-induced disease. Mutant SOD1 aggregates appear to be cleared by proteasomes, at least in vitro, suggesting a potentially important role for proteasome degradation pathways in vivo. G93A SOD1 transgenic mice show an increase in proteasome activity and induction of immuno-proteasome subunits within spinal cord as they develop neurological symptoms.

Overexpression of CCS in G93A-SOD1 mice leads to accelerated neurological deficits with severe mitochondrial pathology.

Cu, Zn superoxide dismutase (SOD1) has been detected within spinal cord mitochondria of mutant SOD1 transgenic mice, a model of familial ALS. The copper chaperone for SOD1 (CCS) provides SOD1 with copper, facilitates the conversion of immature apo-SOD1 to a mature holoform, and influences in yeast the cytosolic/mitochondrial partitioning of SOD1. To determine how CCS affects G93A-SOD1-induced disease, we generated transgenic mice overexpressing CCS and crossed them to G93A-SOD1 or wild-type SOD1 transgenic mice.

Non-neuronal induction of immunoproteasome subunits in an ALS model: possible mediation by cytokines.

Protein aggregation is a pathologic hallmark of familial amyotrophic lateral sclerosis caused by mutations in the Cu, Zn superoxide dismutase gene. Although SOD1-positive aggregates can be cleared by proteasomes, aggregates have been hypothesized to interfere with proteasome activity, leading to a vicious cycle that further enhances aggregate accumulation. To address this issue, we measured proteasome activity in transgenic mice expressing a G93A SOD1 mutation.

Aggregate formation in the spinal cord of mutant SOD1 transgenic mice is reversible and mediated by proteasomes.

Cu,Zn superoxide dismutase (SOD1) mutations cause one form of familial amyotrophic lateral sclerosis by a toxic gain of function that may be related to abnormal protein folding and aggregate formation. However, the processing pathways involved in SOD1 aggregate generation within spinal cord remain unclear. We have now developed an experimental system for studying SOD1 aggregate formation and clearance in intact spinal cord tissue.

Disease progression in a transgenic model of familial amyotrophic lateral sclerosis is dependent on both neuronal and non-neuronal zinc binding proteins.

Mutations in the Cu/Zn superoxide dismutase (SOD1) gene cause one form of familial amyotrophic lateral sclerosis, a progressive disorder of motor neurons leading to weakness and death of affected individuals. Experiments using both transgenic mice expressing mutant SOD1 and SOD1 knock-out mice have demonstrated that disease is caused by a toxic gain of function and not by a loss of normal SOD1 activity. Precise mechanisms underlying mutant SOD1 toxicity are unclear but may involve abnormal interactions between zinc and SOD1.

Upregulation of autocrine-paracrine renin-angiotensin systems in chronic renovascular hypertension.

Introduction: The mechanism by which hypertension is maintained in renovascular hypertension remains poorly defined. Because plasma angiotensin II does not correlate with blood pressure in RVH, we postulated that activation of tissue-specific autocrine-paracrine renin-angiotensin systems may upregulate local production of angiotensin II and maintain hypertension in chronic RVH.

Methods: RVH was induced with a two-kidney one-clip (2K1C) rat model.