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result(s) for
"Delank, Anna"
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Neuron-oligodendrocyte potassium shuttling at nodes of Ranvier protects against inflammatory demyelination
2023
Multiple sclerosis (MS) is a progressive inflammatory demyelinating disease of the CNS. Increasing evidence suggests that vulnerable neurons in MS exhibit fatal metabolic exhaustion over time, a phenomenon hypothesized to be caused by chronic hyperexcitability. Axonal Kv7 (outward-rectifying) and oligodendroglial Kir4.1 (inward-rectifying) potassium channels have important roles in regulating neuronal excitability at and around the nodes of Ranvier. Here, we studied the spatial and functional relationship between neuronal Kv7 and oligodendroglial Kir4.1 channels and assessed the transcriptional and functional signatures of cortical and retinal projection neurons under physiological and inflammatory demyelinating conditions. We found that both channels became dysregulated in MS and experimental autoimmune encephalomyelitis (EAE), with Kir4.1 channels being chronically downregulated and Kv7 channel subunits being transiently upregulated during inflammatory demyelination. Further, we observed that pharmacological Kv7 channel opening with retigabine reduced neuronal hyperexcitability in human and EAE neurons, improved clinical EAE signs, and rescued neuronal pathology in oligodendrocyte-Kir4.1-deficient (OL-Kir4.1-deficient) mice. In summary, our findings indicate that neuron-OL compensatory interactions promoted resilience through Kv7 and Kir4.1 channels and identify pharmacological activation of nodal Kv7 channels as a neuroprotective strategy against inflammatory demyelination.
Journal Article
Protective potential of dimethyl fumarate in a mouse model of thalamocortical demyelination
by
Delank, Anna
,
Speckmann, Erwin J
,
Göbel, Kerstin
in
Animal cognition
,
Animal models
,
Auditory discrimination
2018
Alterations in cortical cellular organization, network functionality, as well as cognitive and locomotor deficits were recently suggested to be pathological hallmarks in multiple sclerosis and corresponding animal models as they might occur following demyelination. To investigate functional changes following demyelination in a well-defined, topographically organized neuronal network, in vitro and in vivo, we focused on the primary auditory cortex (A1) of mice in the cuprizone model of general de- and remyelination. Following myelin loss in this model system, the spatiotemporal propagation of incoming stimuli in A1 was altered and the hierarchical activation of supra- and infragranular cortical layers was lost suggesting a profound effect exerted on neuronal network level. In addition, the response latency in field potential recordings and voltage-sensitive dye imaging was increased following demyelination. These alterations were accompanied by a loss of auditory discrimination abilities in freely behaving animals, a reduction of the nuclear factor-erythroid 2-related factor-2 (Nrf-2) protein in the nucleus in histological staining and persisted during remyelination. To find new strategies to restore demyelination-induced network alteration in addition to the ongoing remyelination, we tested the cytoprotective potential of dimethyl fumarate (DMF). Therapeutic treatment with DMF during remyelination significantly modified spatiotemporal stimulus propagation in the cortex, reduced the cognitive impairment, and prevented the demyelination-induced decrease in nuclear Nrf-2. These results indicate the involvement of anti-oxidative mechanisms in regulating spatiotemporal cortical response pattern following changes in myelination and point to DMF as therapeutic compound for intervention.
Journal Article
The Role of KCNQ-Channels in the Pathophysiology of Multiple Sclerosis
2021
Multiple sclerosis is associated with changes in neuronal stimulus transmission and ion channel expression. Affected include KCNQ channels, voltage-dependent potassium channels that regulate neuronal activity. The anticonvulsant retigabine opens KCNQ channels and thus reduces neuronal excitability. Prophylactic retigabine therapy improved the outcome of experimental autoimmune encephalitis, an MS animal model. Using the Cuprizone model, we examined the influence of the channels on neurodegeneration and showed that mice treated with retigabine suffered less abnormalities in behavioral experiments. This indicates a better learning and memory ability of the animals, which can be strongly influenced by the neurodegenerative processes. Therefore, there are indications of a neuroprotective property of retigabine and, consequently, of an influence of KCNQ channels in the pathophysiology of MS.
Dissertation
Behavioral and hormonal assessment of stress in foals (Equus caballus) throughout the weaning process
by
Delank, Kristin
,
Erhard, Michael
,
Reese, Sven
in
Adaptation
,
Adrenal glands
,
Animal protection
2023
This study had the aim to demonstrate the midterm effects (three weeks) of weaning on foals’ welfare. For this purpose, foals’ behavioral changes and fecal levels metabolites of cortisol were evaluated. The observations took place at the state stud farm of Baden-Wuerttemberg in Germany. Ten foals (six colts and four fillies) were observed from one day before weaning up until three weeks after weaning. Weaning was divided into three blocks, the first in September, the second in October, and the last in November. The behavioral observation was done during an eight-hour period between 7:00 a.m. and 5:00 p.m. The observer documented the exact behavior shown by the foal every five minutes during the eight hours. To scale the stress experienced by the foal, the glucocorticoid metabolite 11,17-dioxoandrostane was measured with the 11-oxoetiocholanolone enzyme immunoassay, which allows assessing the foal’s plasma cortisol level changes throughout the trail through fecal samples. All foals displayed a distinct hormonal stress response to the weaning process through increased fecal cortisol metabolite levels. Their body posture distribution took a shift from mainly moving before weaning to mainly standing during the three weeks after weaning. Compared with the day before weaning, the foals showed less active behavior and significantly increased their resting behavior. Regarding the overall resting behavior, the weaned foals initially increased their time spent resting in a lying position during daytime and then started to decrease the time lying. After weaning, the foals showed a significant increase in resting while standing. In conclusion, the foals showed an expected behavioral development and an expected curve of cortisol metabolite values throughout the study. However, it seemed that the changes had not returned “back to normal” at three weeks after weaning. Therefore, we suggest that weaned foals need a minimum of three weeks to acclimate to the new situation.
Journal Article
Quantitative Whole‐Body Muscle MRI in Adults With Spinal Muscular Atrophy–A Sensitive Tool for Long‐Time Evaluation of Disease Progression
2026
Background Spinal muscular atrophy (SMA) is a neuromuscular disorder characterized by progressive muscle weakness due to SMN protein deficiency. While effective therapies exist, their impact on slowly progressive adult SMA patients remains unclear. Reliable biomarkers for monitoring disease progression and treatment response are urgently needed. This pilot study evaluated the utility of longitudinal quantitative muscle MRI (qMRI) to monitor disease progression in adult SMA patients treated with nusinersen over an extended period. Methods Nine adult patients with genetically confirmed 5q‐SMA underwent whole‐body muscle MRI and clinical assessment, including the Hammersmith Functional Motor Scale‐Expanded (HFMS‐EXP), Revised Upper Limb Module (RULM), and 6 min walk test (6MWT). Muscular fat fraction (mFF) was quantified in 20 muscles over a median follow‐up of 54 months. Results Baseline mFF correlated strongly with clinical measures (HFMS‐EXP: r = −0.90, p = 0.001; 6MWT: r = −0.96, p < 0.001), but not with age at onset or age at MRI. Over the observation period, a significant increase in mFF was detected (averaged annual increase of all studied muscles: 0.47%, p = 0.011), accentuated in the lower leg muscles. In contrast, clinical measures showed no consistent change. Consequently, no significant correlations were found between changes in mFF and clinical scores. Conclusions This study provides the longest reported longitudinal qMRI assessment in adult SMA patients treated with nusinersen, demonstrating that mFF progressively increases despite stable clinical scores. The results suggest that qMRI may be a sensitive and objective biomarker for detecting subtle disease progression in adult SMA, potentially surpassing clinical measures. Quantitative muscle MRI is emerging as an objective biomarker for monitoring therapy in neuromuscular disorders, yet long‐term trajectories in slowly progressive adult spinal muscular atrophy (SMA) remain unclear. In this study, quantitative MRI parameters in nusinersen‐treated adults were longitudinally evaluated and compared with established clinical outcome measures. MRI detected progression with higher sensitivity than conventional measures, supporting its use as an objective addition to the SMA monitoring toolbox and motivating validation in larger cohorts.
Journal Article
Behavioral and hormonal assessment of stress in foals
2023
This study had the aim to demonstrate the midterm effects (three weeks) of weaning on foals' welfare. For this purpose, foals' behavioral changes and fecal levels metabolites of cortisol were evaluated. The observations took place at the state stud farm of Baden-Wuerttemberg in Germany. Ten foals (six colts and four fillies) were observed from one day before weaning up until three weeks after weaning. Weaning was divided into three blocks, the first in September, the second in October, and the last in November. The behavioral observation was done during an eight-hour period between 7:00 a.m. and 5:00 p.m. The observer documented the exact behavior shown by the foal every five minutes during the eight hours. To scale the stress experienced by the foal, the glucocorticoid metabolite 11,17-dioxoandrostane was measured with the 11-oxoetiocholanolone enzyme immunoassay, which allows assessing the foal's plasma cortisol level changes throughout the trail through fecal samples. All foals displayed a distinct hormonal stress response to the weaning process through increased fecal cortisol metabolite levels. Their body posture distribution took a shift from mainly moving before weaning to mainly standing during the three weeks after weaning. Compared with the day before weaning, the foals showed less active behavior and significantly increased their resting behavior. Regarding the overall resting behavior, the weaned foals initially increased their time spent resting in a lying position during daytime and then started to decrease the time lying. After weaning, the foals showed a significant increase in resting while standing. In conclusion, the foals showed an expected behavioral development and an expected curve of cortisol metabolite values throughout the study. However, it seemed that the changes had not returned \"back to normal\" at three weeks after weaning. Therefore, we suggest that weaned foals need a minimum of three weeks to acclimate to the new situation.
Journal Article
Serum chitotriosidase-1 (CHIT1) as candidate biomarker for mitochondriopathies
2025
Background
Neuromuscular diseases (NMDs) and mitochondriopathies are rare and heterogeneous disorders. Diagnosis is often difficult and delayed, partly due to the lack of reliable biomarkers. Chitotriosidase (CHIT1) as a candidate marker for lysosomal storage diseases is elevated in Niemann pick disease type C as a prototype of this group of diseases. Most recently, a relevant role of the lysosomal pathway in mitochondriopathies has been discussed, but markers of lysosomal involvement have not been investigated. Therefore, the aim of this study was to evaluate CHIT1 concentrations in a broad spectrum of NMDs and mitochondriopathies.
Methods
CHIT1 serum concentration of 151 patients with NMD or primary mitochondriopathy was determined by enzyme-linked immunosorbent assay, and compared to 38 healthy controls and 8 patients with Niemann pick disease type C. Results were controlled for age, sex, CRP and CHIT1 polymorphism, and compared to several established markers (CK, FGF21, GDF15).
Results
CHIT1 levels were not altered in NMDs, but significantly increased in mitochondriopathies, within the range of Niemann-Pick patients. Compared to the established biomarkers, CHIT1 and FGF21 showed a similar diagnostic performance, while better results were found for GDF15. However, there was a tendency for higher CHIT1 concentrations in patients with central nervous system involvement (MELAS syndrome), while FGF21 and GDF15 were not relevantly altered in these patients. Consequently, a combination of biomarkers including CHIT1 provided the best overall diagnostic performance.
Conclusions
Serum CHIT1 concentration is significantly elevated in mitochondriopathies compared to healthy controls and other NMD, identifying CHIT1 as potential complementary biomarker in mitochondriopathies.
Journal Article
Behavioral and hormonal assessment of stress in foals (Equus caballus) throughout the weaning process
2023
This study had the aim to demonstrate the midterm effects (three weeks) of weaning on foals’ welfare. For this purpose, foals’ behavioral changes and fecal levels metabolites of cortisol were evaluated. The observations took place at the state stud farm of Baden-Wuerttemberg in Germany. Ten foals (six colts and four fillies) were observed from one day before weaning up until three weeks after weaning. Weaning was divided into three blocks, the first in September, the second in October, and the last in November. The behavioral observation was done during an eight-hour period between 7:00 a.m. and 5:00 p.m. The observer documented the exact behavior shown by the foal every five minutes during the eight hours. To scale the stress experienced by the foal, the glucocorticoid metabolite 11,17-dioxoandrostane was measured with the 11-oxoetiocholanolone enzyme immunoassay, which allows assessing the foal’s plasma cortisol level changes throughout the trail through fecal samples. All foals displayed a distinct hormonal stress response to the weaning process through increased fecal cortisol metabolite levels. Their body posture distribution took a shift from mainly moving before weaning to mainly standing during the three weeks after weaning. Compared with the day before weaning, the foals showed less active behavior and significantly increased their resting behavior. Regarding the overall resting behavior, the weaned foals initially increased their time spent resting in a lying position during daytime and then started to decrease the time lying. After weaning, the foals showed a significant increase in resting while standing. In conclusion, the foals showed an expected behavioral development and an expected curve of cortisol metabolite values throughout the study. However, it seemed that the changes had not returned “back to normal” at three weeks after weaning. Therefore, we suggest that weaned foals need a minimum of three weeks to acclimate to the new situation.
Journal Article