👤 Anja Kretschmer

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

With the gaining prevalence of obesity, related risks during pregnancy are rising. Inflammation and oxidative stress are considered key mechanisms arising in white adipose tissue (WAT) sparking obesity-associated complications and diseases. The established anti-diabetic drug metformin reduces both on a systemic level, but only little is known about such effects on WAT. Because inhibiting these mechanisms in WAT might prevent obesity-related adverse effects, we investigated metformin treatment during pregnancy using a mouse model of diet-induced maternal obesity. After mating, obese mice were randomised to metformin administration. On gestational day G15.5, phenotypic data were collected and perigonadal WAT (pgWAT) morphology and proteome were examined. Metformin treatment reduced weight gain and visceral fat accumulation. We detected downregulation of perilipin-1 as a correlate and observed indications of recovering respiratory capacity and adipocyte metabolism under metformin treatment. By regulating four newly discovered potential adipokines (alpha-1 antitrypsin, Apoa4, Lrg1 and Selenbp1), metformin could mediate anti-diabetic, anti-inflammatory and oxidative stress-modulating effects on local and systemic levels. Our study provides an insight into obesity-specific proteome alterations and shows novel modulating effects of metformin in pgWAT of obese dams. Accordingly, metformin therapy appears suitable to prevent some of obesity's key mechanisms in WAT. Show less

Maternal obesity is a worldwide problem associated with increased risk of metabolic diseases in the offspring. Genetic deletion of the gastric inhibitory polypeptide (GIP) receptor (GIPR) prevents high-fat diet (HFD)-induced obesity in mice due to specific changes in energy and fat cell metabolism. We investigated whether GIP-associated pathways may be targeted by fetal programming and mimicked the situation by exposing pregnant mice to control or HFD during pregnancy (intrauterine [IU]) and lactation (L). Male wild-type (WT) and Gipr(-/-) offspring received control chow until 25 weeks of age followed by 20 weeks of HFD. Gipr(-/-) offspring of mice exposed to HFD during IU/L became insulin resistant and obese and exhibited increased adipose tissue inflammation and decreased peripheral tissue substrate utilization after being reintroduced to HFD, similar to WT mice on regular chow during IU/L. They showed decreased hypothalamic insulin sensitivity compared with Gipr(-/-) mice on control diet during IU/L. DNA methylation analysis revealed increased methylation of CpG dinucleotides and differential transcription factor binding of promoter regions of genes involved in lipid oxidation in the muscle of Gipr(-/-) offspring on HFD during IU/L, which were inversely correlated with gene expression levels. Our data identify GIP-regulated metabolic pathways that are targeted by fetal programming. Show less

Microtubule actin crosslinking factor 1 (MACF1) plays a role in the coordination of microtubules and actin in multiple cellular processes. Here, we show that MACF1 is also critical for ciliogenesis in multiple cell types. Ablation of Macf1 in the developing retina abolishes ciliogenesis, and basal bodies fail to dock to ciliary vesicles or migrate apically. Photoreceptor polarity is randomized, while inner retinal cells laminate correctly, suggesting that photoreceptor maturation is guided by polarity cues provided by cilia. Deletion of MACF1 in adult photoreceptors causes reversal of basal body docking and loss of outer segments, reflecting a continuous requirement for MACF1 function. MACF1 also interacts with the ciliary proteins MKKS and TALPID3. We propose that a disruption of trafficking across microtubles to actin filaments underlies the ciliogenesis defect in cells lacking MACF1 and that MKKS and TALPID3 are involved in the coordination of microtubule and actin interactions. Show less