Clinical classification of cancer cachexia:phenotypic correlates in human skeletal muscle

Aim – To relate muscle phenotype to a range of current diagnostic criteria for cancer cachexia 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). Four diagnostic criteria were used >5%WL, >10% WL, LM, and LM + >2%WL. Patients underwent biopsy of the rectus muscle. Analysis included immunohistochemistry for fibre size and type, protein and nucleic acid concentration, and Western blots for markers of autophagy, SMAD signalling, and inflammation. Results – Compared with non-cachectic cancer patients, if patients were classified by LM or LM + >2%WL, mean muscle fibre diameter was significantly reduced (p = 0.02 and p = 0.001) repectively. No difference in fibre diameter was observed if patients were classified with WL alone. Regardless of classification, there was no difference in fibre number or proportion of fibre type across all myosin heavy chain isoforms. Mean muscle protein content was reduced and the ratio of RNA/DNA decreased if patients were classified by either >5% WL or LM + >2%WL. Compared with non-cachectic patients, when patients were classified according to >5% WL, SMAD3 protein levels were increased (p=0.022) and with >10% WL, beclin (p = 0.05) and ATG5 (p = 0.01) protein levels were also increased. There were no differences in pNFkB or pSTAT3 levels across any of the groups. Conclusions – Whereas fibre type is not targeted selectively, muscle fibre size, biochemical composition and pathway phenotype can vary according to whether the criteria for cachexia include both a measure of low muscularity and weight loss

Automatic Analysis of the Micronucleus Test in Primary Human Lymphocytes Using Image Analysis

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 specific parameter. Various automated systems to replace the tedious and time consuming manual slide analysis procedure have been described. Flow cytrometric approaches have been discussed elsewhere. The ROBIAS image analysis system for both automatic cytotoxicity assessment and highly sensitive micronucleus detection in primary human lymphocytes was developed at Novartis, where the assay is used as to confirm positive results obtained in the MNT in TK6 cells which serves as the primary screening system for genotoxicity profiling in early drug development. The comparison of manual with automatic analysis results showed a high degree of concordance for 27 independent experiments conducted for profiling of 12 compounds. For concentration series of Cyclophosphamide (CP) and Carbendazim (MBC), a very good correlation between automatic and manual analysis could be established, both for the relative division index used as cytotoxicity parameter, and for MN scoring in mono- and bi-nucleated cells. Generally, false positive micronucleus decisions could be controlled by fast and simple relocation of the automatically detected patterns. The possibility to analyze 24 slides within 65 hours by fully automatic analysis over the weekend and the high reproducibility of the results make automatic image processing a powerful tool for the micronucleus analysis in primary human lymphocytes. The automated slide analysis for the MNT in human lymphocytes complements the portfolio of image analysis applications on ROBIAS supporting various assays in genetic toxicology and other biomedical areas

Gamma-H2AX immunofluorescence for the detection of tissue-specific genotoxicity in vivo

The 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). To compare this new assay to a validated standard procedure for DNA damage quantification, tissues from the same animals were also analyzed in the comet assay. An increase in the levels of gamma-H2AX was observed in most of the tissues from animals treated with doxorubicin and ENU. Interestingly, the lesions induced by doxorubicin were not easily detected by the standard comet assay, while they were clearly identified by gamma-H2AX staining. Conversely, EMS appeared strongly positive in the comet assay but only mildly in the gamma-H2AX immunofluorescence. These observations suggest that the two methods could complement each other for DNA damage analysis, where gamma-H2AX staining allows the detection of tissue-specific effects in situ. Moreover, since gamma-H2AX staining can be performed on formalin-fixed and paraffin-embedded tissue sections generated during repeated-dose toxicity studies, it does not require any further treatments or extra procedures during dissection, thus optimizing the use of resources and animals

Brain region-specific enhancement of remyelination and prevention of demyelination by the CSF1R kinase inhibitor BLZ945

Abstract Multiple 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. Here, we investigated the effects of the CSF-1 receptor kinase inhibitor, BLZ945, on central myelination processes in the 5-week murine cuprizone model by non-invasive and longitudinal magnetic resonance imaging (MRI) and histology. Therapeutic 2-week BLZ945 treatment caused a brain region-specific enhancement of remyelination in the striatum/cortex, which was absent in the corpus callosum/external capsule. This beneficial effect correlated positively with microglia reduction, increased oligodendrocytes and astrogliosis. Prophylactic BLZ945 treatment prevented excessive demyelination in the corpus callosum by reducing microglia and increasing oligondendrocytes. In the external capsule oligodendrocytes were depleted but not microglia and a buildup of myelin debris and axonal damage was observed. A similar microglial dysfunction in the external capsule with an increase of myelin debris was obvious in triggering receptor expressed on myeloid cells 2 (TREM2) knock-out mice treated with cuprizone. Finally, therapeutic BLZ945 treatment did not change the disease course in experimental autoimmune encephalomyelitis mice, a peripherally driven neuroinflammation model. Taken together, our data suggest that a short-term therapeutic inhibition of the CSF-1 receptor pathway by BLZ945 in the murine cuprizone model enhances central remyelination by modulating neuroinflammation. Thus, microglia-modulating therapies could be considered clinically for promoting myelination in combination with standard-of-care treatments in MS patients

Genetic models of cleavage-reduced and soluble TREM2 reveal distinct effects on myelination and microglia function in the cuprizone model.

Triggering 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. The TREM2-sol mouse is a new model with selective elimination of plasma membrane TREM2 and a reduced expression of soluble TREM2. In the acute cuprizone model demyelination and remyelination events were reflected by a T2-weighted signal intensity change in magnetic resonance imaging (MRI), most prominently in the external capsule (EC). In contrast to WT and TREM2-IPD, TREM2-sol and TREM2-KO showed an additional increase in MRI signal during the recovery phase. Histological analyses of TREM2-IPD animals revealed no recovery of neuroinflammation as well as of the lysosomal marker LAMP-1 and displayed enhanced cytokine/chemokine levels in the brain. TREM2-sol and, to a much lesser extent, TREM2-KO, however, despite presenting reduced levels of some cytokines/chemokines, showed persistent microgliosis and astrocytosis during recovery, with both homeostatic (TMEM119) as well as activated (LAMP-1) microglia markers increased. This was accompanied, specifically in the EC, by no myelin recovery, with appearance of myelin debris and axonal pathology, while oligodendrocytes recovered. In the chronic model consisting of 12-week cuprizone administration followed by 3-week recovery TREM2-IPD displayed sustained microgliosis and enhanced remyelination in the recovery phase. Taken together, our data suggest that sustained microglia activation led to increased remyelination, whereas microglia without plasma membrane TREM2 and only soluble TREM2 had reduced phagocytic activity despite efficient lysosomal function, as observed in bone marrow-derived macrophages, leading to a dysfunctional phenotype with improper myelin debris removal, lack of remyelination and axonal pathology following cuprizone intoxication

Longitudinal noninvasive magnetic resonance imaging of brain microhemorrhages in BACE inhibitor-treated APP transgenic mice

Currently, several immunotherapy- and BACE inhibitor-based approaches are being tested in the clinic for the treatment of Alzheimer`s disease. A crucial mechanistically related safety concern in case of a fast removal of brain blood vessel-associated amyloid-beta is the exacerbation of microhemorrhages which is already present in the majority of Alzheimer patients. To investigate potential safety liabilities for long-term Bace inhibitor therapies we used aged APP23 mice, an Alzheimer disease model, which robustly develops cerebral amyloid angiopathy (CAA). MRI, a translational tool easily applied in clinical studies, was used for the detection of the very sparse events of microhemorrhages throughout the entire brain, with a subsequent histological validation. 3D reconstruction of in vivo MRI and serial Perls` stained sections allowed a one-to-one matching of lesions and their histopathological characterization. MRI detected small Perls`s positive areas with sufficient extent along the z-axis. Our data demonstrates that volumetric assessment by non-invasive MRI is sensitive and specific to monitor cerebral microhemorrhages in vivo and that Bace inhibitor NB-360 in contrast to β1 antibody treatment of aged APP23 for three months did not exacerbate microhemorrhages

Protein, DNA, and RNA content of the patients involved in the study.

<p>Data (except gender split) are presented as mean (SEM).</p><p> = cachexia group significantly different from the non-cachexia group, (p<0.05 by Student's t test).</p