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Publications (72)
Background
Osteoarthritis (OA) is a chronic degenerative joint disease causing limited mobility and pain, with no curative treatment available. Recent in vivo studies suggested autonomic alterations during OA progression in patients, yet clinical evidence is scarce. Therefore, autonomic tone was analyzed in OA patients via heart rate variability (H...
Purpose (the aim of the study): Osteoarthritis (OA) is a common multifactorial degenerative disease in which the gradual degradation of articular cartilage leads to functional limitations and increased pain in affected joints. The disease is usually diagnosed in late stages and currently incurable. Accordingly, there is great interest in understand...
Purpose (the aim of the study): Osteoarthritis (OA) affects more than 590 million people worldwide, and the economic and personal burden of the disease continues to increase, because there is still no causal treatment. OA is a chronic degenerative disease of the whole joint characterized by articular cartilage degradation, synovial inflammation, su...
Purpose (the aim of the study): Osteoarthritis (OA) is a chronic degenerative joint disease causing limited mobility and chronic pain. OA has multiple risk factors but the exact pathogenic mechanisms are still not fully understood. We recently demonstrated that OA is associated with a significantly decreased heart rate variability (HRV) indicating...
Purpose (the aim of the study): Osteoarthritis (OA), a chronic degenerative disease of the whole joint, has multiple risk factors including age, sex, obesity, joint malalignment, injuries, lifestyle, genetic disposition and nervous influences. The autonomic nervous system (ANS) in particular is beginning to gain more and more attention in the field...
Collaborative manual image analysis by multiple experts in different locations is an essential workflow in biomedical science. However, sharing the images and writing down results by hand or merging results from separate spreadsheets can be error-prone. Moreover, blinding and anonymization are essential to address subjectivity and bias. Here, we pr...
Osteoarthritis (OA) is the most common degenerative joint disorder. Its multifactorial etiology includes age, sex, joint overloading, genetic or nervous influences. In particular, the autonomic nervous system is increasingly gaining in importance. Its two branches, the sympathetic (SNS) and parasympathetic nervous system, are well-balanced under he...
Osteoarthritis (OA) affects the whole joint and leads to chronic pain. The sympathetic nervous system (SNS) seems to be involved in OA pathogenesis, as indicated by in vitro studies as well as by our latest work demonstrating that sympathectomy in mice results in increased subchondral bone volume in the OA knee joint. We assume that chronic stress...
Purpose
Risk factors for the development of pain in the context of knee osteoarthritis (KOA) remain unclear. Radiological findings often do not correlate with clinical findings, so other pathomechanisms in the development and perception of pain must play a role. The purpose of this study is to investigate the correlation of increased sympathetic ne...
The sympathetic nervous system (SNS) is a major regulatory mediator connecting the brain and the immune system that influences accordingly inflammatory processes within the entire body. In the periphery, the SNS exerts its effects mainly via its neurotransmitters norepinephrine (NE) and epinephrine (E), which are released by peripheral nerve ending...
Osteoarthritis (OA) is the most prevalent degenerative joint disease. Besides loss of articular cartilage and synovial inflammation, OA progression is characterized by pathological changes in the subchondral bone. In early OA, subchondral bone remodeling typically shifts to an increased bone resorption. However, as the disease progresses, an increa...
Despite advanced knowledge of the cellular and biomechanical processes of intervertebral disc degeneration (IVDD), the trigger and underlying mechanisms remain unclear. Since the sympathetic nervous system (SNS) has been shown to exhibit catabolic effects in osteoarthritis pathogenesis, it is attractive to speculate that it also influences IVDD. Th...
Matrix metalloproteinases (MMPs) play crucial roles in tissue homeostasis and pathologies by remodeling the extracellular matrix. Previous studies have demonstrated the biological activities of MMP-derived cleavage products. Furthermore, specific fragments can serve as biomarkers. Therefore, an in vitro cleavage assay to identify substrates and cha...
In recent years, the infrapatellar fat pad (IFP) has gained increasing research interest. The contribution of the IFP to the development and progression of knee osteoarthritis (OA) through extensive interactions with the synovium, articular cartilage, and subchondral bone is being considered. As part of the initiation process of OA, IFP secretes ab...
Background
Scientific image analysis is crucial in many research fields but it can be hampered by subjectivity and bias. Thus, image analysis should be performed anonymized by multiple observers and images displayed in a random order. Yet in radiology for example most PACS-viewers display patient metadata which could influence the analysis. Althoug...
Purpose
Recent studies demonstrated a contribution of adrenoceptors (ARs) to osteoarthritis (OA) pathogenesis. Several AR subtypes are expressed in joint tissues and the β2-AR subtype seems to play a major role during OA progression. However, the importance of β2-AR has not yet been investigated in knee OA. Therefore, we examined the development of...
Objective
Osteoarthritis (OA) pathogenesis involves the interaction of articular cartilage with surrounding tissues, which are innervated by tyrosine hydroxylase-positive (TH+) sympathetic nerve fibers suggesting a role of the sympathetic nervous system (SNS) during OA progression. We analyzed the effects of sympathectomy (Syx) in a murine OA model...
Exogenous adenosine and its metabolite inosine exert anti-inflammatory effects in synoviocytes of osteoarthritis (OA) and rheumatoid arthritis (RA) patients. We analyzed whether these cells are able to synthesize adenosine/inosine and which adenosine receptors (ARs) contribute to anti-inflammatory effects. The functionality of synthesizing enzymes...
Adrenoceptors (ARs) mediate the effects of the sympathetic neurotransmitters norepinephrine (NE) and epinephrine (E) in the human body and play a central role in physiologic and pathologic processes. Therefore, ARs have long been recognized as targets for therapeutic agents, especially in the field of cardiovascular medicine. During the past decade...
The incidence of musculoskeletal diseases is steadily increasing with aging of the population. In the past years, extracellular vesicles (EVs) have gained attention in musculoskeletal research. EVs have been associated with various musculoskeletal pathologies as well as suggested as treatment option. EVs play a pivotal role in communication between...
Mucolipidosis type III (MLIII) gamma is a rare inherited lysosomal storage disorder caused by mutations in GNPTG encoding the γ-subunit of GlcNAc-1-phosphotransferase, the key enzyme ensuring proper intracellular location of multiple lysosomal enzymes. Patients with MLIII gamma typically present with osteoarthritis and joint stiffness, suggesting c...
Bone marrow-derived mesenchymal stem cells (BMSCs) represent an alternative to chondrocytes to support cartilage regeneration in osteoarthritis (OA). The sympathetic neurotransmitter norepinephrine (NE) has been shown to inhibit their chondrogenic potential; however, their proliferation capacity under NE influence has not been studied yet. Therefor...
Healthy and degenerating intervertebral discs (IVDs) are innervated by sympathetic nerves, however, adrenoceptor (AR) expression and functionality have never been investigated systematically. Therefore, AR gene expression was analyzed in both tissue and isolated cells from degenerated human IVDs. Furthermore, human IVD samples and spine sections of...
In recent years, first evidences emerged that sympathetic neurotransmitters influence osteoarthritis (OA) manifestation. Joint-resident stem cells might contribute to cartilage repair, however, their chondrogenic function is reduced. The neurotransmitter norepinephrine (NE) was detected in the synovial fluid of trauma and OA patients. Therefore, th...
As part of the pathogenesis of osteoarthritis (OA), chondrocytes lose their phenotype and become hypertrophic, or dedifferentiate, mainly driven by interleukin-1β (IL-1β). The contribution of other factors to the dedifferentiation process is not completely understood. Recent studies suggested a dose-dependent role for the sympathetic neurotransmitt...
Sympathetic nerve fibers and NE are present in healthy and osteoarthritic (OA) synovial tissue and fluid. The potential regenerative role of progenitors in cartilage has been confirmed, though, in OA, these cells exhibit reduced chondrogenic capacity. The aim of this study was to explore the role of NE on proliferation and chondrogenesis of ASCs. S...
Objectives:
The appearance of endogenous tyrosine hydroxylase-positive cells (TH+ cells) in collagen-induced arthritis was associated with an anti-inflammatory effect. Here we investigated putative anti-inflammatory and antinociceptive effects of the transfer of induced, bone marrow stem cell-derived TH+ cells (iTH+ cells) on murine antigen-induce...
Osteoarthritis (OA) can be regarded as a chronic, painful and degenerative disease that affects all tissues of a joint and one of the major endpoints being loss of articular cartilage. In most cases, OA is associated with a variable degree of synovial inflammation. A variety of different cell types including chondrocytes, synovial fibroblasts, adip...
Synovial adipose stem cells (sASC) can be differentiated into catecholamine-expressing sympathetic neuron-like cells to treat experimental arthritis. However, the pro-inflammatory tumor necrosis factor (TNF) is known to be toxic to catecholaminergic cells (see Parkinson disease), and this may prevent anti-inflammatory effects in inflamed tissue. We...
Epigenetic modifiers of the histone deacetylase (HDAC) family contribute to autoimmunity, cancer, HIV infection, inflammatory, and neurodegeneration. Hence, histone deacetylase inhibitors (HDACi), which alter protein acetylation, gene expression patterns, and cell fate decisions, represent promising new drugs for the therapy of these diseases. Wher...
Tumor necrosis factor (TNF) and its receptors TNF receptor type 1 (TNFR1) and type 2 (TNFR2) have a central role in chronic inflammatory diseases. While TNFR1 mainly confers inflammation, activation of TNFR2 elicits not only pro-inflammatory but also anti-inflammatory effects. In this study, we wanted to investigate the anti-inflammatory therapeuti...
The peripheral nervous system is critically involved in metabolism of joint tissue and intervertebral disks (IVD). Nerve fibers of sympathetic and sensory origin innervate synovial tissue and subchondral bone of diarthrodial joints. In pathophysiological situations as in osteoarthritis (OA), rheumatoid arthritis (RA), and IVD degeneration, innervat...
In chronic inflammation, prevention of cAMP degradation by phosphodiesterase-4 (PDE4) inhibition can be anti-inflammatory therapy. However, PDE4 inhibition was not effective in rheumatoid arthritis (RA). Recent studies demonstrated that PDE4/β-arrestin interaction at beta-adrenoceptors resulted in switching from Galphas to Galphai signaling and ERK...
Background
A long-lasting anti-inflammatory effect of generated catecholamine-producing tyrosine hydroxylase-positive (TH+) cells was shown in collagen type II-induced arthritis (CIA). Here, we investigated the importance of TH+ cells in another model of rheumatoid arthritis.
Methods
TH+ cells were generated from murine bone -derived mesenchymal s...
Norepinephrine (NE) was measured in synovial fluid of trauma patients and sympathetic nerve fibers were detected in healthy and osteoarthritic (OA) joint tissues indicating that cartilage pathophysiology might be influenced by sympathetic neurotransmitters. The aim of this study was to elucidate the mostly unknown role of NE in OA chondrocyte metab...
In chronic inflammation, prevention of cAMP degradation by phosphodiesterase-4 (PDE4) inhibition can be anti-inflammatory therapy. However, PDE4 inhibition was uneffective in rheumatoid arthritis (RA). Recent studies demonstrated that PDE4/β-arrestin interaction at β-adrenoceptors resulted in switching from Gαs to Gαi signaling and ERK1/2 activatio...
Objective
Mesenchymal progenitor cell chondrogenesis is the biologic platform for the generation or regeneration of cartilage, but the external influence of the sympathetic nervous system on this process is not yet known. Sympathetic nerve fibers are present in articular tissue, and the sympathetic nervous system influences the musculoskeletal syst...
Studies in rheumatoid arthritis (RA), osteoarthritis (OA) and mice with arthritis demonstrated tyrosine hydroxylase-positive (TH(+)) cells in arthritic synovium and parallel loss of sympathetic nerve fibres. The exact function of TH(+) cells and mode of TH induction are not known.
Synovial cells of RA/OA were isolated and cultured under normoxic/hy...
In previous studies we detected TH-positive, catecholamine-producing cells in inflamed hypoxic synovial tissue. Therefore, the aim of our study was to investigate the influence of hypoxia induced catecholamines on inflammatory responses in arthritis. Synovial cells of rheumatoid arthritis (RA) and osteoarthritis (OA) patients were isolated and cult...
The microenvironment of inflammed joints is hypoxic and hypoxia has been shown to induce tyrosine hydroxylase (TH) in vivo. In previous studies, we detected TH-positive, catecholamine-producing cells in inflamed synovial tissue. Therefore, the aim of our study was to investigate the influence of hypoxia induced catecholamines on inflammatory respon...
Proliferating pannus is in many aspects similar to placental tissue. Both fibroblast-rich tissues have high vascularity, and tissue from patients with rheumatoid arthritis (RA) and patients with osteoarthritis (OA) demonstrates conversion of androgenic prehormones to downstream estrogens. We undertook this study to investigate similarities between...
Musculoskeletal disorders, as non-healing fractures and large bone defects, articular cartilage and subchondral bone injuries, often result in lifelong chronic pain and compromised quality of life. Although generally a natural process, failure of large bone defects to heal such as after complex fractures, resection of tumours, infections, or revisi...
Chondrocyte aging is associated with cartilage degeneration and senescence impairs the regenerative potential of mesenchymal stem cells (MSCs). Estrogen exerts profound effects on human physiology including articular cartilage and MSCs. The present study should analyze the effects of pre- and postmenopausal estrogen concentrations on chondrogenic c...
Human mesenchymal stem cells are a valuable cell source for tissue engineering. Determination of cell number and viability is crucial. However, this can be tested only at the end of cell culture. This study shows that Resazurin dye staining is a reliable tool for evaluation of cell number and viability in culture without cell perturbation.
We undertook this study to examine the effects of estradiol on chondrogenesis of human bone marrow-derived mesenchymal stem cells (MSCs), with consideration of sex-dependent differences in cartilage repair.
Bone marrow was obtained from the iliac crest of young men. Density-gradient centrifugation-separated human MSCs proliferated as a monolayer in...