Publications by authors named "Andreas Wree"

141 Publications

Gender-Specific Effects of Two Treatment Strategies in a Mouse Model of Niemann-Pick Disease Type C1.

Int J Mol Sci 2021 Mar 3;22(5). Epub 2021 Mar 3.

Centre of Transdisciplinary Neuroscience Rostock, D-18147 Rostock, Germany.

In a mouse model of Niemann-Pick disease type C1 (NPC1), a combination therapy (COMBI) of miglustat (MIGLU), the neurosteroid allopregnanolone (ALLO) and the cyclic oligosaccharide 2-hydroxypropyl-β-cyclodextrin (HPßCD) has previously resulted in, among other things, significantly improved motor function. The present study was designed to compare the therapeutic effects of the COMBI therapy with that of MIGLU or HPßCD alone on body and brain weight and the behavior of mice in a larger cohort, with special reference to gender differences. A total of 117 and 123 mice underwent either COMBI, MIGLU only, HPßCD only, or vehicle treatment (Sham), or received no treatment at all (None). In male and female mice, all treatments led to decreased loss of body weight and, partly, brain weight. Concerning motor coordination, as revealed by the accelerod test, male mice benefited from COMBI treatment, whereas female mice benefited from COMBI, MIGLU, and HPßCD treatment. As seen in the open field test, the reduced locomotor activity of male and female mice was not significantly ameliorated in either treatment group. Our results suggest that in mice, each drug treatment scheme had a beneficial effect on at least some of the parameters evaluated compared with Sham-treated mice. Only in COMBI-treated male and female mice were drug effects seen in reduced body and brain weights. Upon COMBI treatment, the increased dosage of drugs necessary for anesthesia in Sham-treated male and female mice was almost completely reduced only in the female groups.
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http://dx.doi.org/10.3390/ijms22052539DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7962008PMC
March 2021

A comparison, using X-ray micro-computed tomography, of the architecture of cancellous bone from the cervical, thoracic and lumbar spine using 240 vertebral bodies from 10 body donors.

Anat Cell Biol 2021 03;54(1):25-34

Department of Internal Medicine IV, Municipal Hospital Suedstadt Rostock, Academic Teaching Hospital of the University of Rostock, Rostock, Germany.

The vertebral trabecular bone has a complex three-dimensional microstructure with an inhomogeneous morphology. Correct identification and assessment of the weakest segments of the cancellous bone may lead to better prediction of fracture risk. The aim of this study was to compare cancellous bone from 240 vertebrae of the cervical, thoracic and lumbar spine of ten body donors with osteoporosis in regard to bone volume fraction (BVF), trabecular thickness, separation, trabecular number and degree of anisotropy, to ascertain why cervical vertebrae rarely fracture, even with severe osteoporosis. Samples were obtained from all vertebrae with a Jamshidi needle (8 Gauge). The investigations were performed with a micro-computed tomography (micro-CT) device (SKYSCAN 1172, RJL Micro & Analytic GmbH, Karlsdorf-Neuthard, Germany). Existing vertebral fractures and the bone mineral density of the lumbar spine were assessed with quantitative CT. Regarding the micro-CT parameters, statistically significant differences were observed between the various sections of the spine. We found a higher BVF, trabecular number and trabecular thickness, as well as a lower trabecular separation of the cervical vertebrae compared to other vertebrae. In addition, the degree of anisotropy in the cervical spine is lower than in the other spinal column sections. These results are age and sex dependent. Thus, the cervical spine has special structural features, whose causes must be determined in further investigations.
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http://dx.doi.org/10.5115/acb.20.269DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8017461PMC
March 2021

Morphometric Characterization of Human Coronary Veins and Subvenous Epicardial Adipose Tissue-Implications for Cardiac Resynchronization Therapy Leads.

Front Cardiovasc Med 2020 8;7:611160. Epub 2020 Dec 8.

Institute of Diagnostic and Interventional Radiology, Pediatric Radiology and Neuroradiology, Rostock University Medical Center, Rostock, Germany.

Subvenous epicardial fat tissue (SEAT), which acts as an electrical insulation, and the venous diameter (VD) both constitute histomorphological challenges for optimal application and lead design in cardiac synchronization therapy (CRT). In this study, we characterized the morphology of human coronary veins to improve the technical design of future CRT systems and to optimize the application of CRT leads. We retrospectively analyzed data from cardiac computed tomography (CT) of 53 patients and did studies of 14 human hearts using the postmortem freeze section technique and micro CT. Morphometric parameters (tributary distances, offspring angles, luminal VD, and SEAT thickness) were assessed. The left posterior ventricular vein (VVSP) had a mean proximal VD of 4.0 ± 1.4 mm, the left marginal vein (VMS) of 3.2 ± 1.5 mm and the anterior interventricular vein (VIA) of 3.9 ± 1.3 mm. More distally (5 cm), VDs decreased to 2.4 ± 0.6 mm, 2.3 ± 0.7 mm, and 2.4 ± 0.6 mm, respectively. In their proximal portions (15 mm), veins possessed mean SEAT thicknesses of 3.2 ± 2.4 (VVSP), 3.4 ± 2.4 mm (VMS), and 4.2 ± 2.8 mm (VIA), respectively. More distally (20-70 mm), mean SEAT thicknesses decreased to alternating low levels of 1.3 ± 1.1 mm (VVSP), 1.7 ± 1.1 mm (VMS), and 4.3 ± 2.6 mm (VIA), respectively. In contrast to the VD, SEAT thicknesses alternated along the further distal vein course and did not display a continuous decrease. Besides the CRT responsiveness of different areas of the LV myocardium, SEAT is a relevant electrophysiological factor in CRT, potentially interfering with sensing and pacing. A sufficient VD is crucial for successful CRT lead placement. Measurements revealed a trend toward greater SEAT thickness for the VIA compared to VVSP and VMS, suggesting a superior signal-to-noise-ratio in VVSP and VMS.
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http://dx.doi.org/10.3389/fcvm.2020.611160DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7793918PMC
December 2020

Quantitative and Qualitative Assessment of Adhesive Thrombo-Fibrotic Lead Encapsulations (TFLE) of Pacemaker and ICD Leads in Arrhythmia Patients-A Study.

Front Cardiovasc Med 2020 30;7:602179. Epub 2020 Nov 30.

Department of Anatomy, Rostock University Medical Center, Rostock, Germany.

The demand for cardiac implantable electronic devices for arrhythmia therapy is still unabated and rising. Despite onward optimizations, lead-related problems such as infections or fractures often necessitate lead extraction. Due to adhesive thrombo-fibrotic lead encapsulations (TFLE) transvenous lead extraction is challenging and risky. However, knowledge on TFLEs and possible correlations with technical lead parameters and dwelling time (DT) were hitherto insufficiently studied. Therefore, we analyzed TFLEs of 62 lead from 35 body donor corpses to gain information for a potential lead design optimization. We examined both TFLE topography on the basis on anatomical landmarks and histo-morphological TFLE characteristics by means of histological paraffin sections and scanning electron microscopy of decellularized samples. The macroscopic analysis revealed that all leads were affected by TFLEs, mainly in the lead bearing veins. Half (47.2%) of the right-ventricular leads possessed adhesions to the tricuspid valve. On average, 49.9 ± 21.8% of the intravascular lead length was covered by TFLE of which 82.8 ± 16.2% were adhesive wall bindings (WB). The discrete TFLEs with at least one WB portion had a mean length of 95.0 ± 64.3 mm and a maximum of 200 mm. Neither sex, DT nor certain technical lead parameters showed distinct tendencies to promote or prevent TFLE. TFLE formation seems to start early in the first 1-2 weeks after implantation. The degree of fibrotization of the TFLE, starting with a thrombus, was reflected by the amount of compacted collagenous fibers and likewise largely independent from DT. TFLE thickness often reached several hundred micrometers. Calcifications were occasionally seen and appeared irregularly along the TFLE sheath. Leadless pacemaker systems have the advantage to overcome the problem with TFLEs but hold their own specific risks and limitations which are not fully known yet.
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http://dx.doi.org/10.3389/fcvm.2020.602179DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7734031PMC
November 2020

Ga-Labelled Tropane Analogues for the Visualization of the Dopaminergic System.

ChemMedChem 2021 Mar 10;16(5):804-808. Epub 2020 Dec 10.

Institute of Nuclear Chemistry, Johannes Gutenberg-University Mainz, Fritz-Strassmann-Weg 2, 55128, Mainz, Germany.

The development of radiometal-labelled pharmaceuticals for neuroimaging could offer great potential due to easier handling during labelling and availability through radionuclide generator systems. Nonetheless, to date, no such tracers are available for positron emission tomography, primarily owing to the challenge of crossing the blood-brain barrier (BBB) and loss of affinity through chelator attachment. We have prepared a variety of Ga-labelled phenyltropanes showing that, through a simple hydrocarbon-linker, it is possible to introduce a chelator onto the lead structure while maintaining its high affinity for hDAT (human dopamine transporter) and simultaneously achieving adequate lipophilicity. One of the candidates, [ Ga]Ga-HBED-hexadiyne-tropane, showed an IC value of 66 nM, together with a log D of 0.96. A μPET study in a hemi-parkinsonian rat model showed a fast wash-out of the tracer, and no specific uptake in the brain, thus implying an inability to penetrate the BBB.
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http://dx.doi.org/10.1002/cmdc.202000820DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7984292PMC
March 2021

Influence of Conditioned Media on the Re-Differentiation Capacity of Human Chondrocytes in 3D Spheroid Cultures.

J Clin Med 2020 Aug 30;9(9). Epub 2020 Aug 30.

Department of Orthopedics, Biomechanics and Implant Technology Research Laboratory, Rostock University Medical Center, 18057 Rostock, Germany.

A major challenge of cell-based therapy for cartilage lesions is the preservation of the chondrogenic phenotype during ex vivo cell cultivation. In this in vitro study, the chondro-inductive capacity of two different hyaline cartilage-conditioned cell culture media on human chondrocytes in 3D spheroids was determined. Media were conditioned by incubation of 200 mg/mL vital or devitalized cartilage matrix in growth media over 35 days. The media were analyzed for the content of soluble procollagen type (Col) II and glycosaminoglycans (GAGs) as well as released TGF-β1, IGF-1 and IGFBP3. Unconditioned medium served as a negative control while the positive medium control was supplemented with TGF-β1 and IGF-1. Spheroid cultures prepared from human chondrocytes were cultivated at 37 °C, 5% CO and 21% O in the respective media and controls. After 14 and 35 days, the deposition of ECM components was evaluated by histological analysis. Vital cartilage-conditioned medium contained significantly higher levels of Col II and active TGF-β1 compared to medium conditioned with the devitalized cartilage matrix. Despite these differences, the incubation with vital as well as devitalized cartilage conditioned medium led to similar results in terms of deposition of proteoglycans and collagen type II, which was used as an indicator of re-differentiation of human chondrocytes in spheroid cultures. However, high density 3D cell cultivation showed a positive influence on re-differentiation.
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http://dx.doi.org/10.3390/jcm9092798DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7564315PMC
August 2020

Identification of Brain-Specific Treatment Effects in NPC1 Disease by Focusing on Cellular and Molecular Changes of Sphingosine-1-Phosphate Metabolism.

Int J Mol Sci 2020 Jun 24;21(12). Epub 2020 Jun 24.

Research Group Anatomy, School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg, 26129 Oldenburg, Germany.

Niemann-Pick type C1 (NPC1) is a lysosomal storage disorder, inherited as an autosomal-recessive trait. Mutations in the gene result in malfunction of the NPC1 protein, leading to an accumulation of unesterified cholesterol and glycosphingolipids. Beside visceral symptoms like hepatosplenomegaly, severe neurological symptoms such as ataxia occur. Here, we analyzed the sphingosine-1-phosphate (S1P)/S1P receptor (S1PR) axis in different brain regions of mice and evaluated specific effects of treatment with 2-hydroxypropyl-β-cyclodextrin (HPβCD) together with the iminosugar miglustat. Using high-performance thin-layer chromatography (HPTLC), mass spectrometry, quantitative real-time PCR (qRT-PCR) and western blot analyses, we studied lipid metabolism in an NPC1 mouse model and human skin fibroblasts. Lipid analyses showed disrupted S1P metabolism in mice in all brain regions, together with distinct changes in /S1PR3 and /S1PR5 expression. Brains of mice showed only weak treatment effects. However, side effects of the treatment were observed in mice. The S1P/S1PR axis seems to be involved in NPC1 pathology, showing only weak treatment effects in mouse brain. expression appears to be affected in human fibroblasts, induced pluripotent stem cells (iPSCs)-derived neural progenitor and neuronal differentiated cells. Nevertheless, treatment-induced side effects make examination of further treatment strategies indispensable.
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http://dx.doi.org/10.3390/ijms21124502DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7352403PMC
June 2020

The initial engraftment of tumor cells is critical for the future growth pattern: a mathematical study based on simulations and animal experiments.

BMC Cancer 2020 Jun 5;20(1):524. Epub 2020 Jun 5.

Competence Center Bioinformatics, Institute for Applied Computer Science, University of Applied Sciences Stralsund, Zur Schwedenschanze 15, 18435, Stralsund, Germany.

Background: Xenograft mouse tumor models are used to study mechanisms of tumor growth and metastasis formation and to investigate the efficacy of different therapeutic interventions. After injection the engrafted cells form a local tumor nodule. Following an initial lag period of several days, the size of the tumor is measured periodically throughout the experiment using calipers. This method of determining tumor size is error prone because the measurement is two-dimensional (calipers do not measure tumor depth). Primary tumor growth can be described mathematically by suitable growth functions, the choice of which is not always obvious. Growth parameters provide information on tumor growth and are determined by applying nonlinear curve fitting.

Methods: We used self-generated synthetic data including random measurement errors to research the accuracy of parameter estimation based on caliper measured tumor data. Fit metrics were investigated to identify the most appropriate growth function for a given synthetic dataset. We studied the effects of measuring tumor size at different frequencies on the accuracy and precision of the estimated parameters. For curve fitting with fixed initial tumor volume, we varied this fixed initial volume during the fitting process to investigate the effect on the resulting estimated parameters. We determined the number of surviving engrafted tumor cells after injection using ex vivo bioluminescence imaging, to demonstrate the effect on experiments of incorrect assumptions about the initial tumor volume.

Results: To select a suitable growth function, measurement data from at least 15 animals should be considered. Tumor volume should be measured at least every three days to estimate accurate growth parameters. Daily measurement of the tumor volume is the most accurate way to improve long-term predictability of tumor growth. The initial tumor volume needs to have a fixed value in order to achieve meaningful results. An incorrect value for the initial tumor volume leads to large deviations in the resulting growth parameters.

Conclusions: The actual number of cancer cells engrafting directly after subcutaneous injection is critical for future tumor growth and distinctly influences the parameters for tumor growth determined by curve fitting.
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http://dx.doi.org/10.1186/s12885-020-07015-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7275472PMC
June 2020

Repeated intrastriatal application of botulinum neurotoxin-A did not influence choline acetyltransferase-immunoreactive interneurons in hemiparkinsonian rat brain - A histological, stereological and correlational analysis.

Brain Res 2020 09 6;1742:146877. Epub 2020 May 6.

Institute of Anatomy, Rostock University Medical Center, D-18057 Rostock, Germany; Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Macroscopic and Clinical Anatomy, Medical University of Graz, A-8010 Graz, Austria. Electronic address:

In Parkinson's disease, dopamine depletion leads to hyperactivity of cholinergic interneurons in the caudate-putamen (CPu). Botulinum neurotoxin-A (BoNT-A) inhibits the release of acetylcholine in the peripheral nervous system and is also thought to act as a local anticholinergic drug when injected intrastriatally. In hemiparkinsonian (hemi-PD) rats, a unilateral intrastriatal injection of 1 ng BoNT-A significantly diminished apomorphine-induced rotation behavior for at least 3 months, the effect fading thereafter. A second intrastriatal BoNT-A application, 6 months after the first one, led to a stronger and longer-lasting, beneficial behavioral reaction. As a single BoNT-A injection was not cytotoxic in the rat striatum and resembled BoNT-A treatment in clinical practice, here, we investigated the structural outcome of repeated intrastriatal BoNT-A injections with respect to striatal volume, the number of choline acetyltransferase-immunoreactive (ChAT-ir) interneurons and of the length of their dendritic arbors, and the numeric density of ChAT-ir BoNT-A-induced varicosities (BiVs). Repeated unilateral intrastriatal BoNT-A application decreased the volume of the injected CPu, but did not significantly change the number of striatal ChAT-ir interneurons. Also, the total dendrite length of ChAT-ir interneurons after repeated BoNT-A application resembled the values in double vehicle-injected hemi-PD rats. In repeatedly BoNT-A-injected hemi-PD rats, the numeric density of ChAT-ir BiVs in the CPu was increased compared with rats only intrastriatally injected once with BoNT-A. Even repeated BoNT-A injections in rat striata did not cause substantial morphological changes in ChAT-ir neuron, except for the increased numeric density of ChAT-ir BiVs.
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http://dx.doi.org/10.1016/j.brainres.2020.146877DOI Listing
September 2020

Prevalence and Mortality of Venous Leg Diseases of the Deep Veins: An Observational Cohort Study Based on German Health Claims Data.

Angiology 2020 05 13;71(5):452-464. Epub 2020 Mar 13.

Institute for Sociology and Demography, University of Rostock, Rostock, Germany.

This study estimates the prevalence and mortality of diseases of the deep veins of the legs such as deep vein thrombosis (DVT), postthrombotic syndrome (PTS), and venous leg ulceration (VLU). We used a random sample of 250 000 patients at age 50+ years of the register of the from 2004 to 2015. Selected manifestations of venous diseases assumed as risk factors for mortality were analyzed using Cox models while adjusting for various basic demographic and health characteristics. The prevalence in 2004 was 0.05% for DVT of the femoral veins, 0.50% for DVT of any deep veins, 0.86% for PTS, and 0.91% for VLU. The mortality rate in 2004 to 2015 was 20.40 deaths/100 person-years for DVT of the femoral veins, 10.69 for DVT of any deep veins, 4.34 for PTS, and 7.02 for VLU. The model revealed a 35% higher risk ( < .001) in patients with any DVT, an 88% higher mortality ( < .001) for femoral DVT, a 23% higher risk ( < .001) for VLU, and no health disadvantage in persons with PTS. Our study revealed an increased mortality for patients with VLU and DVT. Even after adjustment for embolic events and infections of the venous ulcers mortality remained significantly higher.
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http://dx.doi.org/10.1177/0003319720905751DOI Listing
May 2020

Thoracic-paravertebral blocks: comparative anatomical study with different injection techniques and volumes.

Reg Anesth Pain Med 2020 02 2;45(2):102-106. Epub 2019 Nov 2.

Institute of Anatomy, University of Rostock, Rostock, Germany.

Background And Objectives: We hypothesized that different injection techniques and volumes in thoracic-paravertebral blocks (TPVB) lead to different patterns of dye spread. In particular, we investigated whether an alternating injection technique leads to complete staining of all adjacent intercostal nerves.

Methods: This comparative anatomical investigation was performed using 10 or 20 mL of dye (Alcian Blue) in 10 unfixed donor cadavers (54 injections) that were designated for education or research purposes.

Results: In landmark-guided TPVB, the thoracic-paravertebral space (TPVS) was either not stained at all (spread of dye in the paraspinal muscles, n=3) or the dye was predominantly found in the epidural space (n=3). In ultrasound-guided TPVB, the TPVS was correctly identified in all cases (n=48). The sympathetic trunk was stained in 84.6% of injections (multi-injection technique: 100%), independent of injection technique and volume. The epidural space was stained more frequently (p≤0.001) if both the puncture site (sagittal transducer position) and guidance of the needle were more medial (77.8%). Finally, a higher injection volume (20 vs 10 mL) resulted in a higher number of stained intercostal nerves (p=0.04).

Conclusion: For ultrasound-guided techniques, a higher injection volume resulted in a larger number of stained intercostal nerves. Staining of the sympathetic trunk was independent of the injection technique. Epidural spread was observed significantly less frequently if the injection was lateral (transducer transversal) or with a strictly cranial injection direction (transducer sagittal). Landmark-guided injections reliably achieved the TPVS (and the epidural space) only after a needle advance of 2.5 cm after initial contact with the transverse process.
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http://dx.doi.org/10.1136/rapm-2019-100896DOI Listing
February 2020

Defining body-weight reduction as a humane endpoint: a critical appraisal.

Lab Anim 2020 Feb 30;54(1):99-110. Epub 2019 Oct 30.

Rudolf-Zenker-Institute of Experimental Surgery, University Medical Center, Rostock, Germany.

In many animal experiments scientists and local authorities define a body-weight reduction of 20% or more as severe suffering and thereby as a potential parameter for humane endpoint decisions. In this study, we evaluated distinct animal experiments in multiple research facilities, and assessed whether 20% body-weight reduction is a valid humane endpoint criterion in rodents. In most experiments (restraint stress, distinct models for epilepsy, pancreatic resection, liver resection, caloric restrictive feeding and a mouse model for Dravet syndrome) the animals lost less than 20% of their original body weight. In a glioma model, a fast deterioration in body weight of less than 20% was observed as a reliable predictor for clinical deterioration. In contrast, after induction of chronic diabetes or acute colitis some animals lost more than 20% of their body weight without exhibiting major signs of distress. In these two animal models an exclusive application of the 20% weight loss criterion for euthanasia might therefore result in an unnecessary loss of animals. However, we also confirmed that this criterion can be a valid parameter for defining the humane endpoint in other animal models, especially when it is combined with additional criteria for evaluating distress. In conclusion, our findings strongly suggest that experiment and model specific considerations are necessary for the rational integration of the parameter 'weight loss' in severity assessment schemes and humane endpoint criteria. A flexible implementation tailored to the experiment or intervention by scientists and authorities is therefore highly recommended.
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http://dx.doi.org/10.1177/0023677219883319DOI Listing
February 2020

Stimulation of mGluR1/5 Improves Defective Internalization of AMPA Receptors in NPC1 Mutant Mouse.

Cereb Cortex 2020 03;30(3):1465-1480

Translational Neurodegeneration Section "Albrecht Kossel", Department of Neurology, University Medical Center Rostock, Rostock 18147, Germany.

Niemann-Pick type C1 (NPC1) disease is characterized by neurodegeneration caused by cholesterol accumulation in the late endosome/lysosome. In this study, a defective basal and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-stimulated internalization of GluR2-containing AMPA receptors in NPC1-/- cortical neurons was detected. Our results show that the amount of cholesterol and group I metabotropic glutamate receptors (mGluR1/5) in lipid rafts of NPC1-/- cortical tissue and neurons are decreased and their downstream signals of p-ERK are defective, which are restored by a rebalance of cholesterol homeostasis through β-cyclodextrin (β-CD) treatment. Application of 3,5-dihydroxyphenylglycine (DHPG)-a mGluR1/5 agonist-and β-CD markedly increases the internalization of AMPA receptors and decreases over-influx of calcium in NPC1-/- neurons, respectively. Furthermore, the defective phosphorylated GluR2 and protein kinase C signals are ameliorated by the treatment with DHPG and β-CD, respectively, suggesting an involvement of them in internalization dysfunction. Taken together, our data imply that abnormal internalization of AMPA receptors is a critical mechanism for neuronal dysfunction and the correction of dysfunctional mGluR1/5 is a potential therapeutic strategy for NPC1 disease.
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http://dx.doi.org/10.1093/cercor/bhz179DOI Listing
March 2020

Current Challenges in Understanding the Cellular and Molecular Mechanisms in Niemann-Pick Disease Type C1.

Int J Mol Sci 2019 Sep 6;20(18). Epub 2019 Sep 6.

Center of Transdisciplinary Neuroscience Rostock, D-18147 Rostock, Germany.

Rare diseases are a heterogeneous group of very different clinical syndromes. Their most common causes are defects in the hereditary material, and they can therefore be passed on to descendants. Rare diseases become manifest in almost all organs and often have a systemic expressivity, i.e., they affect several organs simultaneously. An effective causal therapy is often not available and can only be developed when the underlying causes of the disease are understood. In this review, we focus on Niemann-Pick disease type C1 (NPC1), which is a rare lipid-storage disorder. Lipids, in particular phospholipids, are a major component of the cell membrane and play important roles in cellular functions, such as extracellular receptor signaling, intracellular second messengers and cellular pressure regulation. An excessive storage of fats, as seen in NPC1, can cause permanent damage to cells and tissues in the brain and peripheral nervous system, but also in other parts of the body. Here, we summarize the impact of NPC1 pathology on several organ systems, as revealed in experimental animal models and humans, and give an overview of current available treatment options.
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http://dx.doi.org/10.3390/ijms20184392DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6771135PMC
September 2019

Continuous Blood Sampling in Small Animal Positron Emission Tomography/Computed Tomography Enables the Measurement of the Arterial Input Function.

J Vis Exp 2019 08 8(150). Epub 2019 Aug 8.

Core Facility Multimodal Small Animal Imaging, Rostock University Medical Center.

For quantitative analysis and bio-kinetic modeling of positron emission tomography/computed tomography (PET/CT) data, the determination of the temporal blood time-activity concentration also known as arterial input function (AIF) is a key point, especially for the characterization of animal disease models and the introduction of newly developed radiotracers. The knowledge of radiotracer availability in the blood helps to interpret PET/CT-derived data of tissue activity. For this purpose, online blood sampling during the PET/CT imaging is advisable to measure the AIF. In contrast to manual blood sampling and image-derived approaches, continuous online blood sampling has several advantages. Besides the minimized blood loss, there is an improved resolution and a superior accuracy for the blood activity measurement. However, the major drawback of online blood sampling is the costly and time-consuming preparation to catheterize the femoral vessels of the animal. Here, we describe an easy and complete workflow for catheterization and continuous blood sampling during small animal PET/CT imaging and compared it to manual blood sampling and an image-derived approach. Using this highly-standardized workflow, the determination of the fluorodeoxyglucose ([F]FDG) AIF is demonstrated. Further, this procedure can be applied to any radiotracer in combination with different animal models to create fundamental knowledge of tracer kinetic and model characteristics. This allows a more precise evaluation of the behavior of pharmaceuticals, both for diagnostic and therapeutic approaches in the preclinical research of oncological, neurodegenerative and myocardial diseases.
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http://dx.doi.org/10.3791/59701DOI Listing
August 2019

A therapy with miglustat, 2-hydroxypropyl-ß-cyclodextrin and allopregnanolone restores splenic cholesterol homeostasis in Niemann-pick disease type C1.

Lipids Health Dis 2019 Jun 28;18(1):146. Epub 2019 Jun 28.

Institute of Anatomy, Rostock University Medical Center, Gertrudenstraße 9, 18057, Rostock, Germany.

Background: Niemann-Pick disease type C1 (NPC1) is an autosomal-recessive lipid-storage disorder with an estimated minimal incidence of 1/120,000 live births. Besides other neuronal and visceral symptoms, NPC1 patients develop spleen dysfunction, isolated spleno- or hepatosplenomegaly and infections. The mechanisms of splenomegaly and alterations of lipid metabolism-related genes in NPC1 disease are still poorly understood.

Methods: Here, we used an NPC1 mouse model to study a splenoprotective effect of a treatment with miglustat, 2-hydroxypropyl-ß-cyclodextrin and allopregnanolone and showed that this treatment has a positive effect on spleen morphology and lipid metabolism.

Results: Disease progress can be halted and blocked at the molecular level. Mutant Npc1 (Npc1) mice showed increased spleen weight and increased lipid accumulation that could be avoided by our treatment. Also, FACS analyses showed that the increased number of splenic myeloid cells in Npc1 mice was normalized by the treatment. Treated Npc1 mice showed decreased numbers of cytotoxic T cells and increased numbers of T helper cells.

Conclusions: In summary, the treatment promotes normal spleen morphology, stabilization of lipid homeostasis and blocking of inflammation, but alters the composition of T cell subtypes.
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http://dx.doi.org/10.1186/s12944-019-1088-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6598286PMC
June 2019

LPA , LPA , LPA , and LPA receptor expression during mouse brain development.

Dev Dyn 2019 05 27;248(5):375-395. Epub 2019 Mar 27.

Institute of Cell Biology and Neurobiology, Center for Anatomy, Charité-Universitätsmedizin Berlin, Berlin, Germany.

Background: LPA is a small bioactive phospholipid that acts as an extracellular signaling molecule and is involved in cellular processes, including cell proliferation, migration, and differentiation. LPA acts by binding and activating at least six known G protein-coupled receptors: LPA . In recent years, LPA has been suggested to play an important role both in normal neuronal development and under pathological conditions in the nervous system.

Results: We show the expression pattern of LPA receptors during mouse brain development by using qRT-PCR, in situ hybridization, and immunocytochemistry. Only LPA , LPA LPA and LPA mRNA transcripts were detected throughout development stages from embryonic day 16 until postnatal day 30 of hippocampus, neocortex, cerebellum, and bulbus olfactorius in our experiments, while expression of LPA and LPA genes was below detection level. In addition to our qRT-PCR results, we also analyzed the cellular protein expression of endogenous LPA receptors, with focus on LPA and LPA within postnatal brain slices and primary neuron differentiation with and without cytoskeleton stabilization and destabilization.

Conclusions: The expression of LPA receptors changes depends on the developmental stage in mouse brain and in cultured hippocampal primary neurons. Interestingly, we found that commercially available antibodies for LPA receptors are largely unspecific.
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http://dx.doi.org/10.1002/dvdy.23DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6593976PMC
May 2019

Botulinum Neurotoxin-A Injected Intrastriatally into Hemiparkinsonian Rats Improves the Initiation Time for Left and Right Forelimbs in Both Forehand and Backhand Directions.

Int J Mol Sci 2019 Feb 25;20(4). Epub 2019 Feb 25.

Institute of Anatomy, Rostock University Medical Center, D-18057 Rostock, Germany.

Forelimb stepping is a widely used test for the assessment of forelimb akinesia in hemiparkinsonian (hemi-PD) rats. The initiation time (IT) is considered the most sensitive parameter in the stepping test procedure. Here we propose a novel, reliable, and simple method for the measurement of IT of both forelimbs in both forehand and backhand directions in rats. Evaluating the same videos taken for quantifying adjusting steps, IT measurements were done without additional experiments. This is in contrast to the classical approach introduced by Olsson et al. (1995), in which separate experiments are necessary. We successfully applied our approach to hemi-PD rats intrastriatally treated with botulinum neurotoxin-A (BoNT-A). In naïve rats, an IT of about 0.62 s was found, and in right-sided hemi-PD rats the IT of the left forepaw increased to about 3.62 s. These hemi-PD rats showed, however, reduced ITs of the impaired left forepaws 1 month and the second time 7 months after induction of hemi-PD via the injection of 1 ng BoNT-A into the ipsilateral striatum, depending on post BoNT-A survival time. The method described offers the possibility of a precise and animal-friendly evaluation of IT in rats, including the beneficial effect of BoNT-A treatment in hemi-PD rats.
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http://dx.doi.org/10.3390/ijms20040992DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6412467PMC
February 2019

Repair of cartilage defects with devitalized osteochondral tissue: A pilot animal study.

J Biomed Mater Res B Appl Biomater 2019 10 30;107(7):2354-2364. Epub 2019 Jan 30.

Department of Orthopaedics, Biomechanics and Implant Technology Research Laboratory, Rostock University Medical Center, Rostock, Germany.

Devitalization using high hydrostatic pressure (HHP) treatment inactivates cells while matrix structure and biomechanical properties are maintained. Because of strong chondroinductive potential of HHP-devitalized cartilage matrix, it may be used as scaffold for reconstruction of (osteo-)chondral lesions. In this pilot study, we evaluated the feasibility of HHP-devitalized osteochondral tissue to repair osteochondral defects in a rabbit model. Removal and reimplantation of osteochondral plugs were performed in 12 female New Zealand White rabbits. From the knee joint of each animal, osteochondral plugs (diameter = 4 mm; depth = 2.5 mm) were harvested and devitalized by HHP (452 MPa for 10 min). Afterward, the plugs were reimplanted into the respective cavity, from where they were taken. Animals were sacrificed 12 weeks postoperatively and the integration of osteochondral plugs was examined using μ-CT, MRI, and histological staining. Furthermore, revitalization of HHP-treated osteochondral plugs was characterized by gene expression analyses. Macroscopic evaluation of tissue repair at implantation sites of HHP-treated osteochondral plugs showed an adequate defect filling 12 weeks after implantation. Plug margins were hardly detectable indicating successful tissue integration. Additionally, gene expression analyses demonstrated initial revitalization of the HHP-treated tissue 12 weeks postoperatively. Our preliminary data revealed that HHP-treated osteochondral plugs could be used to refill osteochondral defects in the knee joint and promote cell migration into defect site. Data indicated that HHP-treated tissue has the potential to act as functional scaffolds for reconstruction of cartilage defects. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 2354-2364, 2019.
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http://dx.doi.org/10.1002/jbm.b.34329DOI Listing
October 2019

Main Olfactory and Vomeronasal Epithelium Are Differently Affected in Niemann-Pick Disease Type C1.

Int J Mol Sci 2018 Nov 12;19(11). Epub 2018 Nov 12.

Department of Anatomy, University of Rostock, 18057 Rostock, Germany.

Introduction: Olfactory impairment is one of the earliest symptoms in neurodegenerative disorders that has also been documented in Niemann-Pick disease type C1 (NPC1). NPC1 is a very rare, neurovisceral lipid storage disorder, characterized by a deficiency of gene function that leads to progressive neurodegeneration. Here, we compared the pathologic effect of defective gene on the vomeronasal neuroepithelium (VNE) with that of the olfactory epithelium (OE) in an NPC1 mouse model.

Methods: Proliferation in the VNE and OE was assessed by applying a bromodeoxyuridine (BrdU) protocol. We further compared the immunoreactivities of anti-olfactory marker protein (OMP), and the lysosomal marker cathepsin-D in both epithelia. To investigate if degenerative effects of both olfactory systems can be prevented or reversed, some animals were treated with a combination of miglustat/allopregnanolone/2-hydroxypropyl-cyclodextrin (HPβCD), or a monotherapy with HPβCD alone.

Results: Using BrdU to label dividing cells of the VNE, we detected a proliferation increase of 215% ± 12% in -/- mice, and 270% ± 10% in combination- treated -/- animals. The monotherapy with HPβCD led to an increase of 261% ± 10.5% compared to sham-treated -/- mice. Similar to the OE, we assessed the high regenerative potential of vomeronasal progenitor cells. OMP reactivity in the VNE of -/- mice was not affected, in contrast to that observed in the OE. Concomitantly, cathepsin-D reactivity in the VNE was virtually absent. Vomeronasal receptor neurons are less susceptible against NPC1 pathology than olfactory receptor neurons. Compared to control mice, however, the VNE of mice displays an increased neuroregenerative potential, indicating compensatory cell renewal.
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http://dx.doi.org/10.3390/ijms19113563DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6274921PMC
November 2018

Human Femoral Vein Diameter and Topography of Valves and Tributaries: A Post Mortem Analysis.

Clin Anat 2018 Oct 21;31(7):1065-1076. Epub 2018 Sep 21.

Department of Anatomy, Rostock University Medical Center, Rostock, Germany.

The femoral vein (FV) is a clinically important vessel. Failure of its valves can lead to chronic venous insufficiency (CVI) with severe manifestations such as painful ulcers. Although they are crucial for identifying suitable implant sites for therapeutic valves, studies on the topography of FV tributaries and valves are rare. Moreover, the femoral vein diameter (FVD) must be known to assess the morphometric requirements for valve implants. To reassess the anatomical requirements for valve implants, 155 FVs from 82 human corpses were examined. FVDs and tributary and valve topographies were assessed using a laboratory straightedge. The FVD increased from 6 mm in the distal femoropopliteal vein to 11 mm in the iliofemoral vein proximal to the saphenofemoral junction (SFJ). Diameters were significantly bigger in males than females. Height correlated positively with FVD. Distal to the SFJ, within a distance of 38 cm, one to eight valves were present. Up to two valves were present within 10 cm proximal to the SFJ. Individual tributary and valve topography must be considered to ensure appropriate design and successful implantation of a venous valve for CVI therapy in the FV. A suitable implant site would be proximal to the SFJ via an infrainguinal transfemoral access. Clin. Anat. 31:1065-1076, 2018. © 2018 Wiley Periodicals, Inc.
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http://dx.doi.org/10.1002/ca.23224DOI Listing
October 2018

Repeated Intrastriatal Botulinum Neurotoxin-A Injection in Hemiparkinsonian Rats Increased the Beneficial Effect on Rotational Behavior.

Toxins (Basel) 2018 09 11;10(9). Epub 2018 Sep 11.

Institute of Anatomy, Rostock University Medical Center, D-18057 Rostock, Germany.

Injection of botulinum neurotoxin-A (BoNT-A) into the striatum of hemiparkinsonian (hemi-PD) rats reduced apomorphine-induced rotation behavior significantly, for at least 3 months. Thereafter, rotation behavior increased again. We injected hemi-PD rats with 1 ng BoNT-A twice, the second injection following 6 months after the first one and tested the rats for apomorphine-induced rotations and spontaneous motor behaviors, i.e., corridor task and stepping test. To test the hypothesis that BoNT-A reduced striatal hypercholinism in hemi-PD rats, the acetylcholinesterase inhibitor donepezil was injected prior to separate apomorphine-induced rotation tests. In hemi-PD rats, the first BoNT-A injection led to a clear reduction of the apomorphine-induced rotations, and the second BoNT-A injection to a more massive and prolonged reaction. In hemi-PD rats whose apomorphine-induced rotation behavior was strongly reduced by an intrastriatal BoNT-A, subsequent donepezil injections led to significant increases of the rotation rate. Concerning corridor task and stepping test, neither first nor second BoNT-A injections changed hemi-PD rats' behavior significantly. The data give evidence for the possibility of repeated intrastriatal administrations of BoNT-A, for treatment of motor symptoms in experimental hemi-PD over a longer time.
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http://dx.doi.org/10.3390/toxins10090368DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6162461PMC
September 2018

Olfactory Performance as an Indicator for Protective Treatment Effects in an Animal Model of Neurodegeneration.

Front Integr Neurosci 2018 14;12:35. Epub 2018 Aug 14.

Institute of Anatomy, Rostock University Medical Center, Rostock, Germany.

Neurodegenerative diseases are often accompanied by olfactory deficits. Here we use a rare neurovisceral lipid storage disorder, Niemann-Pick disease C1 (NPC1), to illustrate disease-specific dynamics of olfactory dysfunction and its reaction upon therapy. Previous findings in a transgenic mouse model ( showed severe morphological and electrophysiological alterations of the olfactory epithelium (OE) and the olfactory bulb (OB) that ameliorated under therapy with combined 2-hydroxypropyl-ß-cyclodextrin (HPßCD)/allopregnanolone/miglustat or HPßCD alone. A buried pellet test was conducted to assess olfactory performance. qPCR for olfactory key markers and several olfactory receptors was applied to determine if their expression was changed under treatment conditions. In order to investigate the cell dynamics of the OB, we determined proliferative and apoptotic activities using a bromodeoxyuridine (BrdU) protocol and caspase-3 (cas-3) activity. Further, we performed immunohistochemistry and western blotting for microglia (Iba1), astroglia (GFAP) and tyrosine hydroxylase (TH). The buried pellet test revealed a significant olfactory deterioration in mice, which reverted to normal levels after treatment. At the OE level, mRNA for olfactory markers showed no changes; the mRNA level of classical olfactory receptor (ORs) was unaltered, that of unique ORs was reduced. In the OB of untreated mice, BrdU and cas-3 data showed increased proliferation and apoptotic activity, respectively. At the protein level, Iba1 and GFAP in the OB indicated increased microgliosis and astrogliosis, which was prevented by treatment. Due to the unique plasticity especially of peripheral olfactory components the results show a successful treatment in NPC1 condition with respect to normalization of olfaction. Unchanged mRNA levels for olfactory marker protein and distinct olfactory receptors indicate no effects in the OE in mice. Olfactory deficits are thus likely due to central deficits at the level of the OB. Further studies are needed to examine if olfactory performance can also be changed at a later onset and interrupted treatment of the disease. Taken together, our results demonstrate that olfactory testing in patients with NPC1 may be successfully used as a biomarker during the monitoring of the treatment.
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http://dx.doi.org/10.3389/fnint.2018.00035DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6102364PMC
August 2018

Acetylcholine Neurotransmitter Receptor Densities in the Striatum of Hemiparkinsonian Rats Following Botulinum Neurotoxin-A Injection.

Front Neuroanat 2018 10;12:65. Epub 2018 Aug 10.

Rostock University Medical Center, Institute of Anatomy, Rostock, Germany.

Cholinergic neurotransmission has a pivotal function in the caudate-putamen, and is highly associated with the pathophysiology of Parkinson's disease. Here, we investigated long-term changes in the densities of the muscarinic receptor subtypes M, M, M (mAchRs) and the nicotinic receptor subtype αβ (nAchRs) in the striatum of the 6-OHDA-induced hemiparkinsonian (hemi-PD) rat model using quantitative receptor autoradiography. Hemi-PD rats exhibited an ipsilateral decrease in striatal mAchR densities between 6 and 16%. Moreover, a massive and constant decrease in striatal nAchR density by 57% was found. A second goal of the study was to disclose receptor-related mechanisms for the positive motor effect of intrastriatally injected Botulinum neurotoxin-A (BoNT-A) in hemi-PD rats in the apomorphine rotation test. Therefore, the effect of intrastriatally injected BoNT-A in control and hemi-PD rats on mAchR and nAchR densities was analyzed and compared to control animals or vehicle-injected hemi-PD rats. BoNT-A administration slightly reduced interhemispheric differences of mAchR and nAchR densities in hemi-PD rats. Importantly, the BoNT-A effect on striatal nAchRs significantly correlated with behavioral testing after apomorphine application. This study gives novel insights of 6-OHDA-induced effects on striatal mAchR and nAchR densities, and partly explains the therapeutic effect of BoNT-A in hemi-PD rats on a cellular level.
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http://dx.doi.org/10.3389/fnana.2018.00065DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6095974PMC
August 2018

Development of a biodegradable antifibrotic local drug delivery system for glaucoma microstents.

Biosci Rep 2018 08 31;38(4). Epub 2018 Aug 31.

Institute of Anatomy, Rostock University Medical Center, Gertrudenstraße 9, Rostock 18057, Germany.

To prevent implant failure due to fibrosis is a major objective in glaucoma research. The present study investigated the antifibrotic effects of paclitaxel (PTX), caffeic acid phenethyl ester (CAPE), and pirfenidone (PFD) coated microstent test specimens in a rat model. Test specimens based on a biodegradable blend of poly(4-hydroxybutyrate) biopolymer and atactic poly(3-hydroxybutyrate) (at.P(3HB)) were manufactured, equipped with local drug delivery (LDD) coatings, and implanted in the subcutaneous white fat depot. Postoperatively, test specimens were explanted and analyzed for residual drug content. Fat depots including the test specimens were histologically analyzed. drug release studies revealed an initial burst for LDD devices. , slow drug release of PTX was found, whereas it already completed 1 week postoperatively for CAPE and PFD LDD devices. Histological examinations revealed a massive cell infiltration in the periphery of the test specimens. Compact fibrotic capsules around the LDD devices were detectable at 4-36 weeks and least pronounced around PFD-coated specimens. Capsules stained positive for extracellular matrix (ECM) components. The presented model offers possibilities to investigate release kinetics and the antifibrotic potential of drugs as well as the identification of more effective agents for a novel generation of drug-eluting glaucoma microstents.
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http://dx.doi.org/10.1042/BSR20180628DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6117617PMC
August 2018

Unilateral Botulinum Neurotoxin-A Injection into the Striatum of C57BL/6 Mice Leads to a Different Motor Behavior Compared with Rats.

Toxins (Basel) 2018 07 17;10(7). Epub 2018 Jul 17.

Institute of Anatomy, Rostock University Medical Center, Gertrudenstrasse 9, D-18057 Rostock, Germany.

Different morphological changes in the caudate-putamen (CPu) of naïve rats and mice were observed after intrastriatal botulinum neurotoxin-A (BoNT-A) injection. For this purpose we here studied various motor behaviors in mice ( = 46) longitudinally up to 9 months after intrastriatal BoNT-A administration as previously reported for rats, and compared both outcomes. Apomorphine- and amphetamine-induced rotational behavior, spontaneous motor behavior, as well as lateralized neglect were studied in mice after the injection of single doses of BoNT-A into the right CPu, comparing them with sham-injected animals. Unilateral intrastriatal injection of BoNT-A in mice induced significantly increased contralateral apomorphine-induced rotations for 1 to 3 months, as well as significantly increased contralateral amphetamine-induced rotations 1 to 9 months after injection. In rats ( = 28), unilateral BoNT-A injection also induced significantly increased contralateral apomorphine-induced rotations 3 months after injection, but did not provoke amphetamine-induced rotations at all. Lateralized sensorimotor integration, forelimb preference, and forelimb stepping were significantly impaired on the left side. The differences in motor behaviors between rats and mice may be caused by different BoNT-A effects on cholinergic and catecholaminergic fibers in rat and mouse striata, interspecies differences in striatal receptor densities, and different connectomes of the basal ganglia.
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http://dx.doi.org/10.3390/toxins10070295DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6070800PMC
July 2018

Fast and reliable dissection of porcine parathyroid glands - A protocol for molecular and histological analyses.

Ann Anat 2018 Sep 21;219:76-81. Epub 2018 Jun 21.

Leibniz Institute for Farm Animal Biology (FBN), Institute of Genome Biology, Wilhelm-Stahl-Allee 2, 18196 Dummerstorf, Germany; Faculty of Agricultural and Environmental Sciences, University Rostock, 18059 Rostock, Germany.

As calcium and phosphorus are of vital importance for life, physiological activity of the parathyroid glands (PTGs) is crucial to maintain mineral homeostasis and bone mineralization. However, PTG-specific molecular routes in response to environmental factors and intrinsic hormonal responses are not yet fully understood. Since nutrient requirements, pathophysiology and functional genomics of pigs are similar to those of humans, pigs might be a suitable model to study the holistic gene expression and physiological aspects of the parathyroid gland, which could be used in both animal sciences and biomedical research. However, due to their small size and hidden location, the dissection of the PTGs, particularly in pigs, is difficult. Therefore, a protocol for untrained dissectors has been established that allows a fast and reliable identification of the PTGs in domestic pigs. Based on their localization within the cranial thymus near the carotid bifurcation, sampling was verified by histological staining and mRNA expression pattern. Analyses revealed the prominence of parathyroid hormone (PTH)-producing chief cells. Moreover, the copy numbers of PTH differed substantially between the PTGs and their surrounding thymus tissue, as PTH was expressed virtually exclusively in the PTGs. The developed protocol will substantially facilitate a fast and reliable dissection of porcine PTGs which is essential for studies characterizing the molecular mechanisms of parathyroid glands, e.g. when applying new feeding strategies in pigs.
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http://dx.doi.org/10.1016/j.aanat.2018.05.007DOI Listing
September 2018

Ultrahigh-Field Quantitative MR Microscopy of the Chicken Eye In Vivo Throughout the In Ovo Period.

Mol Imaging Biol 2019 02;21(1):78-85

Core Facility Small Animal Imaging, Rostock University Medical Center, Schillingallee 69a, 18057, Rostock, Germany.

Purpose: Ultrahigh-field MRI (UHF-MRI) with an in-plane spatial resolution of less than 100 μm is known as MR microscopy (MRM). MRM provides highly resolved anatomical images and allows quantitative assessment of different tissue types using diffusion-weighted imaging (DWI). The aim of the present study was to evaluate the feasibility of combined in vivo anatomical and quantitative assessment of the developing chicken eye in ovo.

Procedures: Thirty-eight fertilized chicken eggs were examined at 7.1 T (ClinScan, Bruker Biospin, Germany) acquiring a dataset comprising T2-weighted anatomical images, DWI, and diffusion tensor imaging. To reduce motion artifacts, the eggs were moderately cooled before and during MR imaging. Two eggs were imaged daily for the entire developmental period, and 36 eggs were examined pairwise at only one time point of the embryonic period. Development of the eye was anatomically and quantitatively assessed.

Results: From the D5 embryonic stage (116-124 h), MRM allowed differentiation between lens and vitreous body. The lens core and periphery were first identified at D9. DWI allowed quantification of lens maturation based on a significant decrease in apparent diffusion coefficient values and course of fractional anisotropy. Repeated moderate cooling had no influence on the development of the chicken embryo.

Conclusions: MRM allows in vivo assessment of embryonic development of the chicken eye in ovo without affecting normal development. The method provides anatomical information supplemented by quantitative evaluation of lens development using DWI. With increasing availability of ultrahigh-field MR systems, this technique may provide a noninvasive complementary tool in the field of experimental ophthalmology.
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http://dx.doi.org/10.1007/s11307-018-1208-9DOI Listing
February 2019

Role of Bone Morphogenetic Protein 7 (BMP7) in the Modulation of Corneal Stromal and Epithelial Cell Functions.

Int J Mol Sci 2018 May 9;19(5). Epub 2018 May 9.

Department of Ophthalmology, Rostock University Medical Center, 18057 Rostock, Germany.

In the cornea, healing of the wounded avascular surface is an intricate process comprising the involvement of epithelial, stromal and neuronal cell interactions. These interactions result to the release of various growth factors that play prominent roles during corneal wound healing response. Bone morphogenetic proteins (BMPs) are unique multi-functional potent growth factors of the transforming growth factor-beta (TGF-β) superfamily. Treatment of corneal epithelial cells with substance P and nerve growth factor resulted to an increase in the expression of BMP7 mRNA. Since BMP7 is known to modulate the process of corneal wound healing, in this present study, we investigated the influence of exogenous rhBMP7 on human corneal epithelial cell and stromal cell (SFs) function. To obtain a high-fidelity expression profiling of activated biomarkers and pathways, transcriptome-wide gene-level expression profiling of epithelial cells in the presence of BMP7 was performed. Gene ontology analysis shows BMP7 stimulation activated TGF-β signaling and cell cycle pathways, whereas biological processes related to cell cycle, microtubule and intermediate filament cytoskeleton organization were significantly impacted in corneal epithelial cells. Scratch wound healing assay showed increased motility and migration of BMP7 treated epithelial cells. BMP7 stimulation studies show activation of MAPK cascade proteins in epithelial cells and SFs. Similarly, a difference in the expression of claudin, Zink finger E-box-binding homeobox 1 was observed along with phosphorylation levels of cofilin in epithelial cells. Stimulation of SFs with BMP7 activated them with increased expression of α-smooth muscle actin. In addition, an elevated phosphorylation of epidermal growth factor receptor following BMP7 stimulation was also observed both in corneal epithelial cells and SFs. Based on our transcriptome analysis data on epithelial cells and the results obtained in SFs, we conclude that BMP7 contributes to epithelial-to-mesenchymal transition-like responses and plays a role equivalent to TGF-β in the course of corneal wound healing.
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http://dx.doi.org/10.3390/ijms19051415DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5983782PMC
May 2018

Experimental Intrastriatal Applications of Botulinum Neurotoxin-A: A Review.

Int J Mol Sci 2018 May 7;19(5). Epub 2018 May 7.

Institute of Anatomy, Rostock University Medical Center, Gertrudenstraße 9, 18057 Rostock, Germany.

Parkinson’s disease (PD) is one of the most frequent neurodegenerative disorders. Its main pathophysiological characteristic is the loss of dopaminergic neurons in the substantia nigra pars compacta followed by a lack of striatal dopaminergic input and a consequent disinhibition of tonically active cholinergic interneurons. The resulting striatal hypercholinism causes major motor symptoms in PD. Anticholinergic pharmacotherapies have antiparkinsonian effects on motor symptoms, but, due to systemic actions, also numerous severe side effects occur on a regular basis. To circumvent these side effects, a local anticholinergic therapy acting exclusively in the striatum would be reasonable. Botulinum neurotoxin-A (BoNT-A) is synthesized by and blocks the release of acetylcholine from the presynaptic bouton. For several decades, BoNT-A has been used successfully for medical and cosmetic purposes to induce controlled paralyses of single muscles. Our group and others investigated the experimental treatment of striatal hypercholinism by the direct injection of BoNT-A into the striatum of rats and mice as well as of hemiparkinsonian animal models. This review gives an overview of the most important results of the experimental intrastriatal BoNT-A application, with a focus on hemiparkinsonian rats.
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http://dx.doi.org/10.3390/ijms19051392DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5983629PMC
May 2018