@article{SchuhmannLanghauserZimmermannetal.2023,
  author    = {Schuhmann, Michael K. and Langhauser, Friederike and Zimmermann, Lena and Bellut, Maximilian and Kleinschnitz, Christoph and Fluri, Felix},
  title     = {Dimethyl fumarate attenuates lymphocyte infiltration and reduces infarct size in experimental stroke},
  series = {International journal of molecular sciences},
  volume    = {24},
  journal   = {International journal of molecular sciences},
  number    = {21},
  doi       = {10.3390/ijms242115540},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-357731},
  year      = {2023},
  abstract  = {Ischemic stroke is associated with exacerbated tissue damage caused by the activation of immune cells and the initiation of other inflammatory processes. Dimethyl fumarate (DMF) is known to modulate the immune response, activate antioxidative pathways, and improve the blood-brain barrier (BBB) after stroke. However, the specific impact of DMF on immune cells after cerebral ischemia remains unclear. In our study, male mice underwent transient middle cerebral artery occlusion (tMCAO) for 30 min and received oral DMF (15 mg/kg) or a vehicle immediately after tMCAO, followed by twice-daily administrations for 7 days. Infarct volume was assessed on T2-weighted magnetic resonance images on days 1 and 7 after tMCAO. Brain-infiltrating immune cells (lymphocytes, monocytes) and microglia were quantified using fluorescence-activated cell sorting. DMF treatment significantly reduced infarct volumes and brain edema. On day 1 after tMCAO, DMF-treated mice showed reduced lymphocyte infiltration compared to controls, which was not observed on day 7. Monocyte and microglial cell counts did not differ between groups on either day. In the acute phase of stroke, DMF administration attenuated lymphocyte infiltration, probably due to its stabilizing effect on the BBB. This highlights the potential of DMF as a therapeutic candidate for mitigating immune cell-driven damage in stroke.},
  language  = {en}
}
@article{FeldheimKesslerFeldheimetal.2022,
  author    = {Feldheim, Jonas and Kessler, Almuth F. and Feldheim, Julia J. and Schulz, Ellina and Wend, David and Lazaridis, Lazaros and Kleinschnitz, Christoph and Glas, Martin and Ernestus, Ralf-Ingo and Brandner, Sebastian and Monoranu, Camelia M. and L{\"o}hr, Mario and Hagemann, Carsten},
  title     = {Effects of long-term temozolomide treatment on glioblastoma and astrocytoma WHO grade 4 stem-like cells},
  series = {International Journal of Molecular Sciences},
  volume    = {23},
  journal   = {International Journal of Molecular Sciences},
  number    = {9},
  issn      = {1422-0067},
  doi       = {10.3390/ijms23095238},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-284417},
  year      = {2022},
  abstract  = {Glioblastoma leads to a fatal course within two years in more than two thirds of patients. An essential cornerstone of therapy is chemotherapy with temozolomide (TMZ). The effect of TMZ is counteracted by the cellular repair enzyme O\(^6\)-methylguanine-DNA methyltransferase (MGMT). The MGMT promoter methylation, the main regulator of MGMT expression, can change from primary tumor to recurrence, and TMZ may play a significant role in this process. To identify the potential mechanisms involved, three primary stem-like cell lines (one astrocytoma with the mutation of the isocitrate dehydrogenase (IDH), CNS WHO grade 4 (HGA)), and two glioblastoma (IDH-wildtype, CNS WHO grade 4) were treated with TMZ. The MGMT promoter methylation, migration, proliferation, and TMZ-response of the tumor cells were examined at different time points. The strong effects of TMZ treatment on the MGMT methylated cells were observed. Furthermore, TMZ led to a loss of the MGMT promoter hypermethylation and induced migratory rather than proliferative behavior. Cells with the unmethylated MGMT promoter showed more aggressive behavior after treatment, while HGA cells reacted heterogenously. Our study provides further evidence to consider the potential adverse effects of TMZ chemotherapy and a rationale for investigating potential relationships between TMZ treatment and change in the MGMT promoter methylation during relapse.},
  language  = {en}
}
@article{MontellanoKluterRueckeretal.2022,
  author    = {Montellano, Felipe A. and Kluter, Elisabeth J. and R{\"u}cker, Viktoria and Ungeth{\"u}m, Kathrin and Mackenrodt, Daniel and Wiedmann, Silke and Dege, Tassilo and Quilitzsch, Anika and Morbach, Caroline and Frantz, Stefan and St{\"o}rk, Stefan and Haeusler, Karl Georg and Kleinschnitz, Christoph and Heuschmann, Peter U.},
  title     = {Cardiac dysfunction and high-sensitive C-reactive protein are associated with troponin T elevation in ischemic stroke: insights from the SICFAIL study},
  series = {BMC Neurology},
  volume    = {22},
  journal   = {BMC Neurology},
  number    = {1},
  doi       = {10.1186/s12883-022-03017-1},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-300119},
  year      = {2022},
  abstract  = {Background Troponin elevation is common in ischemic stroke (IS) patients. The pathomechanisms involved are incompletely understood and comprise coronary and non-coronary causes, e.g. autonomic dysfunction. We investigated determinants of troponin elevation in acute IS patients including markers of autonomic dysfunction, assessed by heart rate variability (HRV) time domain variables. Methods Data were collected within the Stroke Induced Cardiac FAILure (SICFAIL) cohort study. IS patients admitted to the Department of Neurology, W{\"u}rzburg University Hospital, underwent baseline investigation including cardiac history, physical examination, echocardiography, and blood sampling. Four HRV time domain variables were calculated in patients undergoing electrocardiographic Holter monitoring. Multivariable logistic regression with corresponding odds ratios (OR) and 95\% confidence intervals (CI) was used to investigate the determinants of high-sensitive troponin T (hs-TnT) levels ≥14 ng/L. Results We report results from 543 IS patients recruited between 01/2014-02/2017. Of those, 203 (37\%) had hs-TnT ≥14 ng/L, which was independently associated with older age (OR per year 1.05; 95\% CI 1.02-1.08), male sex (OR 2.65; 95\% CI 1.54-4.58), decreasing estimated glomerular filtration rate (OR per 10 mL/min/1.73 m2 0.71; 95\% CI 0.61-0.84), systolic dysfunction (OR 2.79; 95\% CI 1.22-6.37), diastolic dysfunction (OR 2.29; 95\% CI 1.29-4.02), atrial fibrillation (OR 2.30; 95\% CI 1.25-4.23), and increasing levels of C-reactive protein (OR 1.48 per log unit; 95\% CI 1.22-1.79). We did not identify an independent association of troponin elevation with the investigated HRV variables. Conclusion Cardiac dysfunction and elevated C-reactive protein, but not a reduced HRV as surrogate of autonomic dysfunction, were associated with increased hs-TnT levels in IS patients independent of established cardiovascular risk factors.},
  language  = {en}
}
@article{SchanbacherBieberReindersetal.2022,
  author    = {Schanbacher, Constanze and Bieber, Michael and Reinders, Yvonne and Cherpokova, Deya and Teichert, Christina and Nieswandt, Bernhard and Sickmann, Albert and Kleinschnitz, Christoph and Langhauser, Friederike and Lorenz, Kristina},
  title     = {ERK1/2 activity is critical for the outcome of ischemic stroke},
  series = {International Journal of Molecular Sciences},
  volume    = {23},
  journal   = {International Journal of Molecular Sciences},
  number    = {2},
  issn      = {1422-0067},
  doi       = {10.3390/ijms23020706},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-283991},
  year      = {2022},
  abstract  = {Ischemic disorders are the leading cause of death worldwide. The extracellular signal-regulated kinases 1 and 2 (ERK1/2) are thought to affect the outcome of ischemic stroke. However, it is under debate whether activation or inhibition of ERK1/2 is beneficial. In this study, we report that the ubiquitous overexpression of wild-type ERK2 in mice (ERK2\(^{wt}\)) is detrimental after transient occlusion of the middle cerebral artery (tMCAO), as it led to a massive increase in infarct volume and neurological deficits by increasing blood-brain barrier (BBB) leakiness, inflammation, and the number of apoptotic neurons. To compare ERK1/2 activation and inhibition side-by-side, we also used mice with ubiquitous overexpression of the Raf-kinase inhibitor protein (RKIP\(^{wt}\)) and its phosphorylation-deficient mutant RKIP\(^{S153A}\), known inhibitors of the ERK1/2 signaling cascade. RKIP\(^{wt}\) and RKIP\(^{S153A}\) attenuated ischemia-induced damages, in particular via anti-inflammatory signaling. Taken together, our data suggest that stimulation of the Raf/MEK/ERK1/2-cascade is severely detrimental and its inhibition is rather protective. Thus, a tight control of the ERK1/2 signaling is essential for the outcome in response to ischemic stroke.},
  language  = {en}
}
@article{FeldheimWendLaueretal.2022,
  author    = {Feldheim, Jonas and Wend, David and Lauer, Mara J. and Monoranu, Camelia M. and Glas, Martin and Kleinschnitz, Christoph and Ernestus, Ralf-Ingo and Braunger, Barbara M. and Meybohm, Patrick and Hagemann, Carsten and Burek, Malgorzata},
  title     = {Protocadherin Gamma C3 (PCDHGC3) is strongly expressed in glioblastoma and its high expression is associated with longer progression-free survival of patients},
  series = {International Journal of Molecular Sciences},
  volume    = {23},
  journal   = {International Journal of Molecular Sciences},
  number    = {15},
  issn      = {1422-0067},
  doi       = {10.3390/ijms23158101},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-284433},
  year      = {2022},
  abstract  = {Protocadherins (PCDHs) belong to the cadherin superfamily and represent the largest subgroup of calcium-dependent adhesion molecules. In the genome, most PCDHs are arranged in three clusters, α, β, and γ on chromosome 5q31. PCDHs are highly expressed in the central nervous system (CNS). Several PCDHs have tumor suppressor functions, but their individual role in primary brain tumors has not yet been elucidated. Here, we examined the mRNA expression of PCDHGC3, a member of the PCDHγ cluster, in non-cancerous brain tissue and in gliomas of different World Health Organization (WHO) grades and correlated it with the clinical data of the patients. We generated a PCDHGC3 knockout U343 cell line and examined its growth rate and migration in a wound healing assay. We showed that PCDHGC3 mRNA and protein were significantly overexpressed in glioma tissue compared to a non-cancerous brain specimen. This could be confirmed in glioma cell lines. High PCDHGC3 mRNA expression correlated with longer progression-free survival (PFS) in glioma patients. PCDHGC3 knockout in U343 resulted in a slower growth rate but a significantly faster migration rate in the wound healing assay and decreased the expression of several genes involved in WNT signaling. PCDHGC3 expression should therefore be further investigated as a PFS-marker in gliomas. However, more studies are needed to elucidate the molecular mechanisms underlying the PCDHGC3 effects.},
  language  = {en}
}
@article{RolfesRuckDavidetal.2022,
  author    = {Rolfes, Leoni and Ruck, Tobias and David, Christina and Mencl, Stine and Bock, Stefanie and Schmidt, Mariella and Strecker, Jan-Kolja and Pfeuffer, Steffen and Mecklenbeck, Andreas-Schulte and Gross, Catharina and Gliem, Michael and Minnerup, Jens and Schuhmann, Michael K. and Kleinschnitz, Christoph and Meuth, Sven G.},
  title     = {Natural Killer Cells Are Present in Rag1\(^{-/-}\) Mice and Promote Tissue Damage During the Acute Phase of Ischemic Stroke},
  series = {Translational Stroke Research},
  volume    = {13},
  journal   = {Translational Stroke Research},
  number    = {1},
  issn      = {1868-4483},
  doi       = {10.1007/s12975-021-00923-3},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-308924},
  pages     = {197-211},
  year      = {2022},
  abstract  = {Rag1\(^{-/-}\) mice, lacking functional B and T cells, have been extensively used as an adoptive transfer model to evaluate neuroinflammation in stroke research. However, it remains unknown whether natural killer (NK) cell development and functions are altered in Rag1\(^{-/-}\) mice as well. This connection has been rarely discussed in previous studies but might have important implications for data interpretation. In contrast, the NOD-Rag1\(^{null}\)IL2rg\(^{null}\) (NRG) mouse model is devoid of NK cells and might therefore eliminate this potential shortcoming. Here, we compare immune-cell frequencies as well as phenotype and effector functions of NK cells in Rag1\(^{-/-}\) and wildtype (WT) mice using flow cytometry and functional in vitro assays. Further, we investigate the effect of Rag1\(^{-/-}\) NK cells in the transient middle cerebral artery occlusion (tMCAO) model using antibody-mediated depletion of NK cells and adoptive transfer to NRG mice in vivo. NK cells in Rag1\(^{-/-}\) were comparable in number and function to those in WT mice. Rag1\(^{-/-}\) mice treated with an anti-NK1.1 antibody developed significantly smaller infarctions and improved behavioral scores. Correspondingly, NRG mice supplemented with NK cells were more susceptible to tMCAO, developing infarctions and neurological deficits similar to Rag1-/- controls. Our results indicate that NK cells from Rag1-/- mice are fully functional and should therefore be considered in the interpretation of immune-cell transfer models in experimental stroke. Fortunately, we identified the NRG mice, as a potentially better-suited transfer model to characterize individual cell subset-mediated neuroinflammation in stroke.},
  language  = {en}
}
@article{StetterLopezCaperuchipiHoppKraemeretal.2021,
  author    = {Stetter, Christian and Lopez-Caperuchipi, Simon and Hopp-Kr{\"a}mer, Sarah and Bieber, Michael and Kleinschnitz, Christoph and Sir{\´e}n, Anna-Leena and Albert-Weißenberger, Christiane},
  title     = {Amelioration of cognitive and behavioral deficits after traumatic brain injury in coagulation factor XII deficient mice},
  series = {International Journal of Molecular Sciences},
  volume    = {22},
  journal   = {International Journal of Molecular Sciences},
  number    = {9},
  issn      = {1422-0067},
  doi       = {10.3390/ijms22094855},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-284959},
  year      = {2021},
  abstract  = {Based on recent findings that show that depletion of factor XII (FXII) leads to better posttraumatic neurological recovery, we studied the effect of FXII-deficiency on post-traumatic cognitive and behavioral outcomes in female and male mice. In agreement with our previous findings, neurological deficits on day 7 after weight-drop traumatic brain injury (TBI) were significantly reduced in FXII\(^{-/-}\) mice compared to wild type (WT) mice. Also, glycoprotein Ib (GPIb)-positive platelet aggregates were more frequent in brain microvasculature of WT than FXII\(^{-/-}\) mice 3 months after TBI. Six weeks after TBI, memory for novel object was significantly reduced in both female and male WT but not in FXII\(^{-/-}\) mice compared to sham-operated mice. In the setting of automated home-cage monitoring of socially housed mice in IntelliCages, female WT mice but not FXII\(^{-/-}\) mice showed decreased exploration and reacted negatively to reward extinction one month after TBI. Since neuroendocrine stress after TBI might contribute to trauma-induced cognitive dysfunction and negative emotional contrast reactions, we measured peripheral corticosterone levels and the ration of heart, lung, and spleen weight to bodyweight. Three months after TBI, plasma corticosterone levels were significantly suppressed in both female and male WT but not in FXII\(^{-/-}\) mice, while the relative heart weight increased in males but not in females of both phenotypes when compared to sham-operated mice. Our results indicate that FXII deficiency is associated with efficient post-traumatic behavioral and neuroendocrine recovery.},
  language  = {en}
}
@article{KoenigerBellMifkaetal.2021,
  author    = {Koeniger, Tobias and Bell, Luisa and Mifka, Anika and Enders, Michael and Hautmann, Valentin and Mekala, Subba Rao and Kirchner, Philipp and Ekici, Arif B. and Schulz, Christian and W{\"o}rsd{\"o}rfer, Philipp and Mencl, Stine and Kleinschnitz, Christoph and Erg{\"u}n, S{\"u}leyman and Kuerten, Stefanie},
  title     = {Bone marrow-derived myeloid progenitors in the leptomeninges of adult mice},
  series = {Stem Cells},
  volume    = {39},
  journal   = {Stem Cells},
  number    = {2},
  doi       = {10.1002/stem.3311},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-224452},
  pages     = {227 -- 239},
  year      = {2021},
  abstract  = {Although the bone marrow contains most hematopoietic activity during adulthood, hematopoietic stem and progenitor cells can be recovered from various extramedullary sites. Cells with hematopoietic progenitor properties have even been reported in the adult brain under steady-state conditions, but their nature and localization remain insufficiently defined. Here, we describe a heterogeneous population of myeloid progenitors in the leptomeninges of adult C57BL/6 mice. This cell pool included common myeloid, granulocyte/macrophage, and megakaryocyte/erythrocyte progenitors. Accordingly, it gave rise to all major myelo-erythroid lineages in clonogenic culture assays. Brain-associated progenitors persisted after tissue perfusion and were partially inaccessible to intravenous antibodies, suggesting their localization behind continuous blood vessel endothelium such as the blood-arachnoid barrier. Flt3\(^{Cre}\) lineage tracing and bone marrow transplantation showed that the precursors were derived from adult hematopoietic stem cells and were most likely continuously replaced via cell trafficking. Importantly, their occurrence was tied to the immunologic state of the central nervous system (CNS) and was diminished in the context of neuroinflammation and ischemic stroke. Our findings confirm the presence of myeloid progenitors at the meningeal border of the brain and lay the foundation to unravel their possible functions in CNS surveillance and local immune cell production.},
  language  = {en}
}
@article{HeuschmannMontellanoUngethuemetal.2021,
  author    = {Heuschmann, Peter U. and Montellano, Felipe A. and Ungeth{\"u}m, Kathrin and R{\"u}cker, Viktoria and Wiedmann, Silke and Mackenrodt, Daniel and Quilitzsch, Anika and Ludwig, Timo and Kraft, Peter and Albert, Judith and Morbach, Caroline and Frantz, Stefan and St{\"o}rk, Stefan and Haeusler, Karl Georg and Kleinschnitz, Christoph},
  title     = {Prevalence and determinants of systolic and diastolic cardiac dysfunction and heart failure in acute ischemic stroke patients: The SICFAIL study},
  series = {ESC Heart Failure},
  volume    = {8},
  journal   = {ESC Heart Failure},
  number    = {2},
  doi       = {10.1002/ehf2.13145},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-225656},
  pages     = {1117-1129},
  year      = {2021},
  abstract  = {Aims Ischaemic stroke (IS) might induce alterations of cardiac function. Prospective data on frequency of cardiac dysfunction and heart failure (HF) after IS are lacking. We assessed prevalence and determinants of diastolic dysfunction (DD), systolic dysfunction (SD), and HF in patients with acute IS. Methods and results The Stroke-Induced Cardiac FAILure in mice and men (SICFAIL) study is a prospective, hospital-based cohort study. Patients with IS underwent a comprehensive assessment of cardiac function in the acute phase (median 4 days after IS) including clinical examination, standardized transthoracic echocardiography by expert sonographers, and determination of blood-based biomarkers. Information on demographics, lifestyle, risk factors, symptoms suggestive of HF, and medical history was collected by a standardized personal interview. Applying current guidelines, cardiac dysfunction was classified based on echocardiographic criteria into SD (left ventricular ejection fraction < 52\% in men or <54\% in women) and DD (≥3 signs of DD in patients without SD). Clinically overt HF was classified into HF with reduced, mid-range, or preserved ejection fraction. Between January 2014 and February 2017, 696 IS patients were enrolled. Of them, patients with sufficient echocardiographic data on SD were included in the analyses {n = 644 patients [median age 71 years (interquartile range 60-78), 61.5\% male]}. In these patients, full assessment of DD was feasible in 549 patients without SD (94\%). Prevalence of cardiac dysfunction and HF was as follows: SD 9.6\% [95\% confidence interval (CI) 7.6-12.2\%]; DD in patients without SD 23.3\% (95\% CI 20.0-27.0\%); and clinically overt HF 5.4\% (95\% CI 3.9-7.5\%) with subcategories of HF with preserved ejection fraction 4.35\%, HF with mid-range ejection fraction 0.31\%, and HF with reduced ejection fraction 0.78\%. In multivariable analysis, SD and fulfilment of HF criteria were associated with history of coronary heart disease [SD: odds ratio (OR) 3.87, 95\% CI 1.93-7.75, P = 0.0001; HF: OR 2.29, 95\% CI 1.04-5.05, P = 0.0406] and high-sensitive troponin T at baseline (SD: OR 1.78, 95\% CI 1.31-2.42, P = 0.0003; HF: OR 1.66, 95\% CI 1.17-2.33, P = 0.004); DD was associated with older age (OR 1.08, 95\% CI 1.05-1.11, P < 0.0001) and treated hypertension vs. no hypertension (OR 2.84, 95\% CI 1.23-6.54, P = 0.0405). Conclusions A substantial proportion of the study population exhibited subclinical and clinical cardiac dysfunction. SICFAIL provides reliable data on prevalence and determinants of SD, DD, and clinically overt HF in patients with acute IS according to current guidelines, enabling further clarification of its aetiological and prognostic role.},
  language  = {en}
}
@article{SimonIpekHomolaetal.2018,
  author    = {Simon, Micha and Ipek, Rojda and Homola, Gy{\"o}rgy A. and Rovituso, Damiano M. and Schampel, Andrea and Kleinschnitz, Christoph and Kuerten, Stefanie},
  title     = {Anti-CD52 antibody treatment depletes B cell aggregates in the central nervous system in a mouse model of multiple sclerosis},
  series = {Journal of Neuroinflammation},
  volume    = {15},
  journal   = {Journal of Neuroinflammation},
  number    = {225},
  doi       = {10.1186/s12974-018-1263-9},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-176120},
  year      = {2018},
  abstract  = {Background: Multiple sclerosis (MS) is a chronic autoimmune disease of the central nervous system (CNS) for which several new treatment options were recently introduced. Among them is the monoclonal anti-CD52 antibody alemtuzumab that depletes mainly B cells and T cells in the immune periphery. Considering the ongoing controversy about the involvement of B cells and in particular the formation of B cell aggregates in the brains of progressive MS patients, an in-depth understanding of the effects of anti-CD52 antibody treatment on the B cell compartment in the CNS itself is desirable. Methods: We used myelin basic protein (MBP)-proteolipid protein (PLP)-induced experimental autoimmune encephalomyelitis (EAE) in C57BL/6 (B6) mice as B cell-dependent model of MS. Mice were treated intraperitoneally either at the peak of EAE or at 60 days after onset with 200 μg murine anti-CD52 vs. IgG2a isotype control antibody for five consecutive days. Disease was subsequently monitored for 10 days. The antigen-specific B cell/antibody response was measured by ELISPOT and ELISA. Effects on CNS infiltration and B cell aggregation were determined by immunohistochemistry. Neurodegeneration was evaluated by Luxol Fast Blue, SMI-32, and Olig2/APC staining as well as by electron microscopy and phosphorylated heavy neurofilament serum ELISA. Results: Treatment with anti-CD52 antibody attenuated EAE only when administered at the peak of disease. While there was no effect on the production of MP4-specific IgG, the treatment almost completely depleted CNS infiltrates and B cell aggregates even when given as late as 60 days after onset. On the ultrastructural level, we observed significantly less axonal damage in the spinal cord and cerebellum in chronic EAE after anti-CD52 treatment. Conclusion: Anti-CD52 treatment abrogated B cell infiltration and disrupted existing B cell aggregates in the CNS.},
  language  = {en}
}