Publications by authors named "Dirk Koczan"

The PI3K-AKT and MEK-ERK signaling pathways are integral to fundamental cellular processes such as proliferation, viability, and differentiation. In granulosa cells (GCs), these pathways are activated by FSH and IGF1 through respective receptors. We investigated the comparative transcriptome changes induced by AKT and ERK pathways using corresponding inhibitors in GCs.

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Article Synopsis
  • The study focuses on hyperplastic stromal cells from a Holstein cow's left ovary, which show a fibroblast-like shape and stop growing after the 8th culture passage.
  • It confirms the non-cancerous nature of these cells through various assays and indicates they do not produce estradiol, while vimentin is prominently expressed in their cytoskeleton.
  • A gene expression analysis revealed 1396 differentially expressed genes, with significant activation of pathways related to cell proliferation and mitochondrial function, suggesting the cells have altered growth characteristics.
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He, we show that combined use of the EZH2 inhibitor GSK126 and the CDK4/6 inhibitor abemaciclib synergistically enhances antitumoral effects in preclinical GBM models. Dual blockade led to HIF1α upregulation and CalR translocation, accompanied by massive impairment of mitochondrial function. Basal oxygen consumption rate, ATP synthesis, and maximal mitochondrial respiration decreased, confirming disrupted endoplasmic reticulum-mitochondrial homeostasis.

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Background: Despite remarkable advances in the therapy of multiple sclerosis (MS), patients with MS may still experience relapses. High-dose short-term methylprednisolone (MP) remains the standard treatment in the acute management of MS relapses due to its potent anti-inflammatory and immunosuppressive properties. However, there is a lack of studies on the cell type-specific transcriptome changes that are induced by this synthetic glucocorticoid (GC).

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Thiazolopyridines are a highly relevant class of small molecules, which have previously shown a wide range of biological activities. Besides their anti-tubercular, anti-microbial and anti-viral activities, they also show anti-cancerogenic properties, and play a role as inhibitors of cancer-related proteins. Herein, the biological effects of the thiazolopyridine AV25R, a novel small molecule with unknown biological effects, were characterized.

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Increased life expectancy in industrialized countries is causing an increased incidence of osteoporosis and the need for bioactive bone implants. The integration of implants can be improved physically, but mainly by chemical modifications of the material surface. It was recognized that amino-group-containing coatings improved cell attachment and intracellular signaling.

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Background: Nutrition has not only an impact on the general wellbeing of an animal but can also affect reproductive processes. In cattle, feeding regimes can influence the age of puberty onset and alter gonadal development. We analyzed effects of different milk replacer (MR) feeding regimes during rearing on ovarian physiology with specific emphasis on the numbers as well as gene expression characteristics of granulosa cells (GCs) at the age of puberty onset.

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Background: The immune response is a crucial factor for mediating the benefit of cardiac cell therapies. Our previous research showed that cardiomyocyte transplantation alters the cardiac immune response and, when combined with short-term pharmacological CCR2 inhibition, resulted in diminished functional benefit. However, the specific role of innate immune cells, especially CCR2 macrophages on the outcome of cardiomyocyte transplantation, is unclear.

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Background: Multiple sclerosis (MS) is a chronic, inflammatory and neurodegenerative disease that leads to irreversible damage to the brain and spinal cord. The goal of so-called "immune reconstitution therapies" (IRTs) is to achieve long-term disease remission by eliminating a pathogenic immune repertoire through intense short-term immune cell depletion. B cells are major targets for effective immunotherapy in MS.

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Estradiol and progesterone are the primary sex steroids produced by the ovary. Upon luteinizing hormone surge, estradiol-producing granulosa cells convert into progesterone-producing cells and eventually become large luteal cells of the corpus luteum. Signaling pathways and transcription factors involved in the cessation of estradiol and simultaneous stimulation of progesterone production in granulosa cells are not clearly understood.

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The myxozoan parasite is the causative agent of proliferative kidney disease (PKD)-a disease of salmonid fishes, notably of the commercially farmed rainbow trout . Both wild and farmed salmonids are threatened by this virulent/deadly disease, a chronic immunopathology characterized by massive lymphocyte proliferation and hyperplasia, which manifests as swollen kidneys in susceptible hosts. Studying the immune response towards the parasite helps us understand the causes and consequences of PKD.

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Background: Multiple sclerosis (MS) is a chronic immune-mediated disease of the central nervous system to which a genetic predisposition contributes. Over 200 genetic regions have been associated with increased disease risk, but the disease-causing variants and their functional impact at the molecular level are mostly poorly defined. We hypothesized that single-nucleotide polymorphisms (SNPs) have an impact on pre-mRNA splicing in MS.

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Both bromodomain and extra-terminal domain (BET) proteins and spleen tyrosine kinase (SYK) represent promising targets in diffuse large B-cell (DLBCL) and Burkitt's lymphoma (BL). We evaluated the anti-lymphoma activity of the isoform-specific bivalent BET inhibitor AZD5153 (AZD) and the pan-BET inhibitor I-BET151 (I-BET) as single agents and in combination with SYK inhibitor Entospletinib (Ento) in vitro. The effect of the single agents on cell proliferation and metabolic activity was evaluated in two DLBCL and two BL cell lines.

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Background: Schistosomiasis is a severe parasitic disease that is primarily driven by the host's immune response to schistosome eggs trapped in tissue and by the granulomatous inflammatory and fibrotic reaction they cause. Despite significant progress in understanding the complex immunological processes involved in the relationship between schistosomes and their host, neither an effective vaccine against the infection nor anti-fibrotic drugs currently exists, making the search for new targets for schistosome drugs and vaccine candidates even more important. In order to identify new molecular targets for defense against or elimination of the parasite, we investigate herein the interplay between the host and male or female schistosomes, clearly separating this from the action of the parasite eggs.

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Constitutive activation of cyclin-dependent kinases (CDKs) or arginine auxotrophy are hallmarks of Glioblastoma multiforme (GBM). The latter metabolic defect renders tumor cells vulnerable to arginine-depleting substances, such as arginine deiminase from Streptococcus pyogenes (SpyADI). Previously, we confirmed the susceptibility of patient-derived GBM cells towards SpyADI as well as CDK inhibitors (CDKis).

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Article Synopsis
  • Aquaculture management practices can cause stress responses in fish like maraena whitefish, similar to those observed in rainbow trout and Atlantic salmon.
  • Physiological changes, such as elevated cortisol levels and reduced immune cell activity, were noted after handling, although cortisol levels did not significantly differ from control fish.
  • Gene expression analysis revealed specific stress and immune pathways activated after handling, indicating potential negative impacts on the health and welfare of maraena whitefish in aquaculture settings.
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Background: Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system with a well-established genetic contribution to susceptibility. Over 200 genetic regions have been linked to the inherited risk of developing MS, but the disease-causing variants and their functional effects at the molecular level are still largely unresolved. We hypothesised that MS-associated single-nucleotide polymorphisms (SNPs) affect the recognition and enzymatic cleavage of primary microRNAs (pri-miRNAs).

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Background: Metabolic stress, as negative energy balance on one hand or obesity on the other hand can lead to increased levels of free fatty acids in the plasma and follicular fluid of animals and humans. In an earlier study, we showed that increased oleic acid (OA) concentrations affected the function of cultured bovine granulosa cells (GCs). Here, we focus on genome wide effects of increased OA concentrations.

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Current therapeutic approaches have met limited clinical success for glioblastoma multiforme (GBM). Since GBM harbors genomic alterations in cyclin-dependent kinases (CDKs), targeting these structures with specific inhibitors (CDKis) is promising. Here, we describe the antitumoral potential of selective CDKi on low-passage GBM 2D- and 3D models, cultured as neurospheres (NSCs) or glioma stem-like cells (GSCs).

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In cells, intrinsic endogenous direct current (DC) electric fields (EFs) serve as morphogenetic cues and are necessary for several important cellular responses including activation of multiple signaling pathways, cell migration, tissue regeneration and wound healing. Endogenous DC EFs, generated spontaneously following injury in physiological conditions, directly correlate with wound healing rate, and different cell types respond to these EFs via directional orientation and migration. Application of external DC EFs results in electrode polarity and is known to activate intracellular signaling events in specific direction.

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Chronic obstructive pulmonary disease (COPD) poses a major risk for public health, yet remarkably little is known about its detailed pathophysiology. Definition of COPD as nonreversible pulmonary obstruction revealing more about spatial orientation than about mechanisms of pathology may be a major reason for this. We conducted a controlled observational study allowing for simultaneous assessment of clinical and biological development in COPD.

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We investigated the influence of syngeneic cardiomyocyte transplantation after myocardial infarction (MI) on the immune response and cardiac function. Methods and Results: We show for the first time that the immune response is altered as a result of syngeneic neonatal cardiomyocyte transplantation after MI leading to improved cardiac pump function as observed by magnetic resonance imaging in C57BL/6J mice. Interestingly, there was no improvement in the capillary density as well as infarct area as observed by CD31 and Sirius Red staining, respectively.

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The physico-chemical surface design of implants influences the surrounding cells. Osteoblasts on sharp-edged micro-topographies revealed an impaired cell phenotype, function and Ca mobilization. The influence of edges and ridges on the Wnt/β-catenin pathway in combination with the cells' stress response has not been clear.

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Background: High-molecular-weight kininogen is a cofactor of the human contact system, an inflammatory response mechanism that is activated during sepsis. It has been shown that high-molecular-weight kininogen contributes to endotoxemia, but is not critical for local host defense during pneumonia by Gram-negative bacteria. However, some important pathogens, such as Streptococcus pyogenes, can cleave kininogen by contact system activation.

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