Peripheral nervous system (PNS) toxicity assessment in non-clinical safety studies is challenging and relies mostly on histopathological assessment. The present work aims to identify blood-based biomarkers that could detect peripheral neuropathy in rats upon exposure to neurotoxic compounds. Three anticancer agents (oxaliplatin, cisplatin, paclitaxel) and a developmental compound (NVS-1) were assessed in male rats (Wistar Han).
View Article and Find Full Text PDFBranaplam is a splicing modulator previously under development as a therapeutic agent for Spinal Muscular Atrophy Type 1 and Huntington's disease. Branaplam increased the levels of survival motor neuron protein in preclinical studies and was well tolerated in early clinical studies; however, peripheral neurotoxicity was observed in a preclinical safety study in juvenile dogs. The aim of this study was to determine whether serum neurofilament light chain (NfL) concentrations in dogs could serve as a monitoring biomarker for branaplam-induced peripheral neurotoxicity.
View Article and Find Full Text PDFThe allosteric inhibitor of the mechanistic target of rapamycin (mTOR) everolimus reduces seizures in tuberous sclerosis complex (TSC) patients through partial inhibition of mTOR functions. Due to its limited brain permeability, we sought to develop a catalytic mTOR inhibitor optimized for central nervous system (CNS) indications. We recently reported an mTOR inhibitor () that is able to block mTOR functions in the mouse brain and extend the survival of mice with neuronal-specific ablation of the 1 gene.
View Article and Find Full Text PDFTriggering receptor expressed on myeloid cells 2 (TREM2) is a cell-surface immunoreceptor expressed on microglia, osteoclasts, dendritic cells and macrophages. Heterozygous loss-of-function mutations in TREM2, including mutations enhancing shedding form the cell surface, have been associated with myelin/neuronal loss and neuroinflammation in neurodegenerative diseases, such as Alzheimer`s disease and Frontotemporal Dementia. Using the cuprizone model, we investigated the involvement of soluble and cleavage-reduced TREM2 on central myelination processes in cleavage-reduced (TREM2-IPD), soluble-only (TREM2-sol), knockout (TREM2-KO) and wild-type (WT) mice.
View Article and Find Full Text PDFOfatumumab is the first, fully human, anti-CD20 monoclonal antibody in Phase 3 development for multiple sclerosis (MS). The study focused on changes in lymphocyte subsets in blood and lymphoid tissues and on potential novel biomarkers as a result of anti-CD20 antibody action in Cynomolgus monkeys treated with human equivalent doses of subcutaneous (s.c.
View Article and Find Full Text PDFThe phosphorylation of histone H2AX in Serine 139 (gamma-H2AX) marks regions of DNA double strand breaks and contributes to the recruitment of DNA repair factors to the site of DNA damage. Gamma-H2AX is used widely as DNA damage marker in vitro, but its use for genotoxicity assessment in vivo has not been extensively investigated. Here, we developed an image analysis system for the precise quantification of the gamma-H2AX signal, which we used to monitor DNA damage in animals treated with known genotoxicants (EMS, ENU and doxorubicin).
View Article and Find Full Text PDFThe beta-site amyloid precursor protein cleaving enzyme-1 (BACE-1) initiates the generation of amyloid-β (Aβ), and the amyloid cascade leading to amyloid plaque deposition, neurodegeneration, and dementia in Alzheimer's disease (AD). Clinical failures of anti-Aβ therapies in dementia stages suggest that treatment has to start in the early, asymptomatic disease states. The BACE-1 inhibitor CNP520 has a selectivity, pharmacodynamics, and distribution profile suitable for AD prevention studies.
View Article and Find Full Text PDFMultiple sclerosis (MS) is a chronic inflammatory disease affecting the central nervous system (CNS). While multiple effective immunomodulatory therapies for MS exist today, they lack the scope of promoting CNS repair, in particular remyelination. Microglia play a pivotal role in regulating myelination processes, and the colony-stimulating factor 1 (CSF-1) pathway is a key regulator for microglia differentiation and survival.
View Article and Find Full Text PDFCurrently, several immunotherapies and BACE (Beta Site APP Cleaving Enzyme) inhibitor approaches are being tested in the clinic for the treatment of Alzheimer's disease. A crucial mechanism-related safety concern is the exacerbation of microhemorrhages, which are already present in the majority of Alzheimer patients. To investigate potential safety liabilities of long-term BACE inhibitor therapy, we used aged amyloid precursor protein (APP) transgenic mice (APP23), which robustly develop cerebral amyloid angiopathy.
View Article and Find Full Text PDFBackground: Alzheimer's disease (AD) is the most common form of dementia, the number of affected individuals is rising, with significant impacts for healthcare systems. Current symptomatic treatments delay, but do not halt, disease progression. Genetic evidence points to aggregation and deposition of amyloid-β (Aβ) in the brain being causal for the neurodegeneration and dementia typical of AD.
View Article and Find Full Text PDFBackground: Cachexia affects the majority of patients with advanced cancer and is associated with a reduction in treatment tolerance, response to therapy, and duration of survival. One impediment towards the effective treatment of cachexia is a validated classification system.
Methods: 41 patients with resectable upper gastrointestinal (GI) or pancreatic cancer underwent characterisation for cachexia based on weight-loss (WL) and/or low muscularity (LM).
The in vitro micronucleus test (MNT) is a well-established test for early screening of new chemical entities in industrial toxicology. For assessing the clastogenic or aneugenic potential of a test compound, micronucleus induction in cells has been shown repeatedly to be a sensitive and a specific parameter. Various automated systems to replace the tedious and time-consuming visual slide analysis procedure as well as flow cytometric approaches have been discussed.
View Article and Find Full Text PDFThis article describes the first step toward full (that includes conditions for both absence and presence of metabolic activation) validation and drug discovery application of a 96-well, automated, high-content micronucleus (HCMN) assay. The current validation tests were performed using Chinese hamster ovary cells, in the absence of metabolic activation, against three distinct sets of drug-like compounds that represent all stages of a drug discovery pipeline. A compound categorization scheme was created based on quantitative relationships between micronucleus (MN) signals, cytotoxicity, and compound solubility.
View Article and Find Full Text PDFSulfonic acid esters are considered as potentially alkylating agents that may exert genotoxic effects in bacterial and mammalian cell systems. One possible source of human exposure stems from drug synthesis when the salt-forming agents methanesulfonic acid, benzenesulfonic acid or p-toluenesulfonic acid are used together with alcoholic solvents such as methanol, ethanol and propanol. In this study computer-assisted structural considerations and in vitro approaches (Ames mutagenicity test using Salmonella typhimurium strains TA98 and TA100, and the micronucleus test using L5178Y mouse lymphoma cells) were used to assess the genotoxic properties of 19 sulfonic esters.
View Article and Find Full Text PDFWe evaluated the suitability of the alkaline comet assay as a screening test in industrial routine testing of new chemicals. Thirty-six pharmaceutical compounds with unknown genotoxic potential were tested comparatively in the comet assay and micronucleus test (MNT) using V79 Chinese hamster cells. The comparison of results is generally based on at least two independent experiments, each with two replicate cultures at a minimum of three concentrations.
View Article and Find Full Text PDFIn recent years the Comet assay (or single cell gel electrophoresis assay) has been established as a rapid and sensitive method for the detection of DNA damage. For early genotoxicity screening of new chemical entities in industrial toxicology, the Comet assay is more and more used for assessment of the DNA damaging potential of a test compound. In order to increase compound screening throughput, we have established an image analysis system for fully automated measurement of microscope slides processed in the Comet assay.
View Article and Find Full Text PDFThe immunosuppressive drug, cyclosporin A (CsA), which is successfully used to prevent rejection in organ transplantation, induces renal side-effects as shown by a decrease in glomerular filtration rate and ultrafiltration coefficient regulated by the tone of mesangial cells.The aim of the present study was to investigate the effect of CsA on isolated glomeruli and mesangial cells, which constitute appropriate in vitro models for renal vasoreactivity studies. The roles of different intracellular and extracellular mediators such as calcium, endothelin-1 (ET-1), prostaglandins (TXA(2 )and PGI(2)) and reactive oxygen intermediates (ROIs) were analysed.
View Article and Find Full Text PDFThe in vitro micronucleus test is a well established test for early screening of new chemical entities in industrial toxicology. For assessing the clastogenic or aneugenic potential of a test compound, micronucleus induction in cells has been shown repeatedly to be a sensitive and specific parameter. As a measure for numerical and structural chromosome aberrations, the in vitro micronucleus test consists of determining the frequency of micronucleated cells in a representative fraction of cells in a culture.
View Article and Find Full Text PDFCell Biol Toxicol
December 1994
The mouse bone marrow micronucleus assay is an in vivo test commonly used in the pharmaceutical industry to evaluate the genotoxic potential of new compounds. The test detects agent-induced chromosomal damage or damage of the mitotic spindle apparatus. In this paper the state-of-the-art in automated rodent micronucleus evaluation using computerized image analysis in combination with high-quality slides obtained by the cellulose column fractionation technique is reviewed.
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