👤 Franz F Konen

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system with distinct subtypes, relapsing MS (RMS) and primary progressive MS (PPMS), which differ in clinical course and underlying immunopathology. Cytokines are pleiotropic mediators of inflammatory and regenerative processes and are considered important contributors to the pathophysiology of MS. Ocrelizumab, a CD20-targeting monoclonal antibody, is approved for the treatment of patients with RMS and PPMS, yet its effects on circulating cytokines and neurotrophic factors remain incompletely understood. In this prospective observational study, 84 patients with MS (57 RMS, 27 PPMS) were analyzed regarding demographic data, disease activity and serum cytokine profiles before and 6 months after the start of ocrelizumab therapy. Baseline analyses revealed distinct cytokine signatures between patients with RMS and PPMS, with higher levels of several proinflammatory cytokines and chemokines in patients with RMS. Following ocrelizumab treatment, divergent cytokine profiles between patients with RMS and PPMS were partially attenuated, with significant modulation of Th1-associated chemokines and an increase in brain-derived neurotrophic factor (BDNF) observed in patients with RMS. In contrast, cytokine signatures in patients with PPMS remained largely unaffected by ocrelizumab treatment. Patients with RMS with disease activity during the first 6 months of ocrelizumab treatment showed a significant increase in different chemokines compared to baseline compared with patients without disease activity or those with PPMS. Our findings support divergent immunological mechanisms in RMS and PPMS, with a stronger cytokine-driven pathology and more pronounced immunomodulatory effects of ocrelizumab on the cytokine profile in patients with RMS. Show less

Accurate modelling of molecular changes in Alzheimer's disease (AD) dementia is crucial for understanding the mechanisms driving neuronal pathology and for developing treatments. Synaptic dysfunction has long been implicated as a mechanism underpinning memory dysfunction in AD and may result in part from changes in adenosine deaminase acting on RNA (ADAR) mediated RNA editing of the GluA2 subunit of AMPA receptors and changes in AMPA receptor function at the post synaptic cleft. However, few studies have investigated changes in proteins which influence RNA editing and notably, AD studies that focus on studying changes in protein expression, rather than changes in mRNA, often use traditional western blotting. Here, we demonstrate the value of automated capillary western blotting to investigate the protein expression of AMPA receptor subunits (GluA1-4), the ADAR RNA editing proteins (ADAR1-3), and proteins known to regulate RNA editing (PIN1, WWP2, FXR1P, and CREB1), in the J20 AD mouse model. We describe extensive optimisation and validation of the automated capillary western blotting method, demonstrating the use of total protein to normalise protein load, in addition to characterising the optimal protein/antibody concentrations to ensure accurate protein quantification. Following this, we assessed changes in proteins of interest in the hippocampus of 44-week-old J20 AD mice. We observed an increase in the expression of ADAR1 p110 and GluA3 and a decrease in ADAR2 in the hippocampus of 44-week-old J20 mice. These changes signify a shift in the balance of proteins that play a critical role at the synapse. Regression analysis revealed unique J20-specific correlations between changes in AMPA receptor subunits, ADAR enzymes, and proteins that regulate ADAR stability in J20 mice, highlighting potential mechanisms mediating RNA-editing changes found in AD. Our findings in J20 mice generally reflect changes seen in the human AD brain. This study underlines the importance of novel techniques, like automated capillary western blotting, to assess protein expression in AD. It also provides further evidence to support the hypothesis that a dysregulation in RNA editing-related proteins may play a role in the initiation and/or progression of AD. Show less