A Phase 1 study of GDC-0134, a dual leucine zipper kinase inhibitor, in ALS.

Objective: Dual leucine zipper kinase (DLK), which regulates the c-Jun N-terminal kinase pathway involved in axon degeneration and apoptosis following neuronal injury, is a potential therapeutic target in amyotrophic lateral sclerosis (ALS). This first-in-human study investigated safety, tolerability, and pharmacokinetics (PK) of oral GDC-0134, a small-molecule DLK inhibitor. Plasma neurofilament light chain (NFL) levels were explored in GDC-0134-treated ALS patients and DLK conditional knockout (cKO) mice.

A multi-matrix HILIC-MS/MS method for the quantitation of endogenous small molecule neurological biomarker N-acetyl aspartic acid (NAA).

A multi-matrix hydrophilic interaction liquid chromatography tandem mass spectrometric method (HILIC-MS/MS) was developed for the quantitation of N-Acetyl Aspartic acid (NAA) using stable isotope labeled internal standard, D3-NAA in various biological matrices such as human plasma, human CSF, mouse plasma, brain and spinal cord. A high throughput 96-well plate format supported liquid extraction (SLE) procedure was developed and used for sample preparation. Mass spectrometric analysis of NAA was performed using selected reaction monitoring transitions in positive electrospray ionization mode.

Domain-specific free thiol variant characterization of an IgG1 by reversed-phase high-performance liquid chromatography mass spectrometry.

Measurement of free thiols in antibody therapeutics is important for product development and assessment of critical quality attributes. Earlier studies demonstrated fast separation of free thiol variants of IgG1 using reversed-phase high performance liquid chromatography (RP-HPLC) with diphenyl resin. Here, we report using N-tert-butylmaleimide (NtBM) alkylation followed by RP-HPLC and online mass spectrometry for rapid total and domain-specific free thiol characterization of IgG1.

Development of a rapid RP-UHPLC-MS method for analysis of modifications in therapeutic monoclonal antibodies.

Chemical or enzymatic modifications of therapeutic monoclonal antibodies (MAbs) that have high risk to safety and efficacy are defined as critical quality attributes (CQAs). During therapeutic MAbs process development, thorough characterization and quantitative monitoring of CQAs requires a variety of analytical techniques. This paper describes the development of a rapid analytical method to assess modifications in MAbs, based on the analysis of subdomains with molecular weights of ∼25kDa.

NanoDisk containing super aggregated amphotericin B: a high therapeutic index antifungal formulation with enhanced potency.

Objectives: NanoDisk-amphotericin B (ND-AMB) is a protein-phospholipid bioparticle containing a "super aggregate" form of antifungal AMB. While lipid-based formulations of AMB, including liposomal AMB (L-AMB), are safer than the deoxycholate (DOC) solubilized form (DOC-AMB), the potency of lipid-based formulations is attenuated. We have developed an AMB-based therapy that is both well tolerated and fully efficacious.

Intravenous injection of apolipoprotein A-V reconstituted high-density lipoprotein decreases hypertriglyceridemia in apoav-/- mice and requires glycosylphosphatidylinositol-anchored high-density lipoprotein-binding protein 1.

Objective: Apolipoprotein A-V (apoA-V), a minor protein associated with lipoproteins, has a major effect on triacylglycerol (TG) metabolism. We investigated whether apoA-V complexed with phospholipid in the form of a reconstituted high-density lipoprotein (rHDL) has potential utility as a therapeutic agent for treatment of hypertriglyceridemia (HTG) when delivered intravenously.

Methods And Results: Intravenous injection studies were performed in genetically engineered mouse models of severe HTG, including apoav-/- and gpihbp1-/- mice.

A phospholipid-apolipoprotein A-I nanoparticle containing amphotericin B as a drug delivery platform with cell membrane protective properties.

Amphotericin B (AMB), a potent antifungal agent, has been employed as an inhalable therapy for pulmonary fungal infections. We recently described a novel nano-sized delivery vehicle composed of phospholipid (PL) and apolipoprotein A-I, NanoDisk (ND), to which we added AMB as a payload (ND-AMB). The goal of the present study was to evaluate whether ND-AMB, compared to other formulations, preserves lung cell integrity in vitro, as AMB can be toxic to mammalian cells and reduce lung function when inhaled.

Cognition, learning behaviour and hippocampal synaptic plasticity are not disrupted in mice over-expressing the cholesterol transporter ABCG1.

Background: Cognitive deficits are a hallmark feature of both Down Syndrome (DS) and Alzheimer's Disease (AD). Extra copies of the genes on chromosome 21 may also play an important role in the accelerated onset of AD in DS individuals. Growing evidence suggests an important function for cholesterol in the pathogenesis of AD, particularly in APP metabolism and production of A beta peptides.

Why lipids are important for Alzheimer disease?

Several lines of evidence suggest that dysregulated lipid metabolism may participate in the pathogenesis of Alzheimer's disease (AD). Epidemiologic studies suggest that elevated mid-life plasma cholesterol levels may be associated with an increased risk of AD and that statin use may reduce the prevalence of AD. Cellular studies have shown that the levels and distribution of intracellular cholesterol markedly affect the processing of amyloid precursor protein into A beta peptides, which are the toxic species that accumulate as amyloid plaques in the AD brain.

Overexpression of human ABCG1 does not affect atherosclerosis in fat-fed ApoE-deficient mice.

Objective: The purpose of this study was to evaluate the effects of whole body overexpression of human ABCG1 on atherosclerosis in apoE(-/-) mice.

Methods And Results: We generated BAC transgenic mice in which human ABCG1 is expressed from endogenous regulatory signals, leading to a 3- to 7-fold increase in ABCG1 protein across various tissues. Although the ABCG1 BAC transgene rescued lung lipid accumulation in ABCG1(-/-) mice, it did not affect plasma lipid levels, macrophage cholesterol efflux to HDL, atherosclerotic lesion area in apoE(-/-) mice, or levels of tissue cholesterol, cholesterol ester, phospholipids, or triglycerides.

ABCG1 influences the brain cholesterol biosynthetic pathway but does not affect amyloid precursor protein or apolipoprotein E metabolism in vivo.

Cholesterol homeostasis is of emerging therapeutic importance for Alzheimer's disease (AD). Agonists of liver-X-receptors (LXRs) stimulate several genes that regulate cholesterol homeostasis, and synthetic LXR agonists decrease neuropathological and cognitive phenotypes in AD mouse models. The cholesterol transporter ABCG1 is LXR-responsive and highly expressed in brain.

The cholesterol transporter ABCG1 modulates the subcellular distribution and proteolytic processing of beta-amyloid precursor protein.

Although intracellular cholesterol levels are known to influence the proteolysis of beta-amyloid precursor protein (APP), the effect of specific genes that regulate cholesterol metabolism on APP processing remains poorly understood. The cholesterol transporter ABCG1 facilitates cholesterol efflux to HDL and is expressed in brain. Notably, the human ABCG1 gene maps to chromosome 21q22.

Elevated plasma triglyceride levels precede amyloid deposition in Alzheimer's disease mouse models with abundant A beta in plasma.

Dietary or pharmacological manipulation of plasma lipids markedly influences amyloid deposition in animal models of Alzheimer's Disease (AD). However, it is not known whether baseline plasma lipids in AD models differ from wild-type littermates throughout the natural history of disease. To address this question, we measured plasma total cholesterol and triglyceride levels over time in three transgenic AD mouse models in the absence of dietary or pharmacological treatments.

The absence of ABCA1 decreases soluble ApoE levels but does not diminish amyloid deposition in two murine models of Alzheimer disease.

ABCA1, a cholesterol transporter expressed in the brain, has been shown recently to be required to maintain normal apoE levels and lipidation in the central nervous system. In addition, ABCA1 has been reported to modulate beta-amyloid (Abeta) production in vitro. These observations raise the possibility that ABCA1 may play a role in the pathogenesis of Alzheimer disease.

Deficiency of ABCA1 impairs apolipoprotein E metabolism in brain.

ABCA1 is a cholesterol transporter that is widely expressed throughout the body. Outside the central nervous system (CNS), ABCA1 functions in the biogenesis of high-density lipoprotein (HDL), where it mediates the efflux of cholesterol and phospholipids to apolipoprotein (apo) A-I. Deficiency of ABCA1 results in lack of circulating HDL and greatly reduced levels of apoA-I.

The ATP-binding cassette transporter 1 mediates lipid efflux from Sertoli cells and influences male fertility.

The liver X receptor/retinoid X receptor (LXR/RXR)-regulated gene ABCA1 effluxes cellular cholesterol and phospholipid to apolipoprotein A1 (apoA1), which is the rate-limiting step in high-density lipoprotein synthesis. The RXR pathway plays a critical role in testicular lipid trafficking, and RXRbeta-deficient male mice are sterile and accumulate lipids in Sertoli cells. Here, we demonstrate that ABCA1 mRNA and protein are abundant in Sertoli cells, whereas germ cells express little ABCA1.