Oncogenic transcription factors lacking enzymatic activity or targetable binding pockets are typically considered "undruggable". An example is provided by the EWS-FLI1 oncoprotein, whose continuous expression and activity as transcription factor are critically required for Ewing sarcoma tumor formation, maintenance, and proliferation. Because neither upstream nor downstream targets have so far disabled its oncogenic potential, we performed a high-throughput drug screen (HTS), enriched for FDA-approved drugs, coupled to a Global Protein Stability (GPS) approach to identify novel compounds capable to destabilize EWS-FLI1 protein by enhancing its degradation through the ubiquitin-proteasome system.
View Article and Find Full Text PDFBackground: The injection of mesenchymal stem cells (MSCs) mitigates fat accumulation in released rotator cuff muscle after tendon repair in rodents.
Purpose: To investigate whether the injection of autologous MSCs halts muscle-to-fat conversion after tendon repair in a large animal model for rotator cuff tendon release via regional effects on extracellular fat tissue and muscle fiber regeneration.
Study Design: Controlled laboratory study.
As the excitation-contraction coupling is inseparable during voluntary exercise, the relative contribution of the mechanical and neural input on hypertrophy-related molecular signalling is still poorly understood. Herein, we use a rat in-vivo strength exercise model with an electrically-induced standardized excitation pattern, previously shown to induce a load-dependent increase in myonuclear number and hypertrophy, to study acute effects of load on molecular signalling. We assessed protein abundance and specific phosphorylation of the four protein kinases FAK, mTOR, p70S6K and JNK after 2, 10 and 28 min of a low- or high-load contraction, in order to assess the effects of load, exercise duration and muscle-type on their response to exercise.
View Article and Find Full Text PDFSilverleaf nightshade () is a highly successful invasive weed that has caused agricultural losses both in its home and invaded ranges. Surveying 50 sub-populations over 36,000 km in its native range in South Texas, we investigated the interactions among soil type, population size, plant height, herbivory, and plant defenses in its home range with the expectation that populations growing in the plant's preferred sandier soils would host larger colonies of healthier and better defended plants. At each sampling location, on randomly selected plants, we measured height, insect herbivore damage, and presence, and density of internode spines.
View Article and Find Full Text PDFObjective: Expression of the de-adhesive extracellular matrix protein tenascin-C (TNC) is associated with the early postnatal development of articular cartilage which is both load-dependent and associated with chondrocyte differentiation. We assessed morphological changes in the articular cartilage of TNC deficient mice at postnatal ages of 1, 4 and 8 weeks compared to age-matched wildtype mice.
Results: Cartilage integrity was assessed based on hematoxylin and eosin stained-sections from the tibial bone using a modified Mankin score.
The clinically aggressive alveolar rhabdomyosarcoma (RMS) subtype is characterized by expression of the oncogenic fusion protein PAX3-FOXO1, which is critical for tumorigenesis and cell survival. Here, we studied the mechanism of cell death induced by loss of PAX3-FOXO1 expression and identified a novel pharmacologic combination therapy that interferes with PAX3-FOXO1 biology at different levels. Depletion of PAX3-FOXO1 in fusion-positive (FP)-RMS cells induced intrinsic apoptosis in a NOXA-dependent manner.
View Article and Find Full Text PDFSarcolemma-based focal adhesions (costameres) are a central hub for the cytoskeletal anchoring of myofibrils and mechano-regulated signaling. Here we report the time course of alterations in focal adhesion-associated signaling and fiber composition in rat soleus muscle after Achilles tenotomy. The report includes data from tenotomized muscles and contralateral mock controls to expose whether muscle degeneration after tenotomy is due to the transection of the Achilles tendon, or circumjacent surgical manipulations of the tendon.
View Article and Find Full Text PDFIntroduction: Gene polymorphisms are associated with athletic phenotypes relying on maximal or continued power production and affect the specialization of skeletal muscle composition with endurance or strength training of untrained subjects. We tested whether prominent polymorphisms in genes for angiotensin converting enzyme (ACE), tenascin-C (TNC), and actinin-3 (ACTN3) are associated with the differentiation of cellular hallmarks of muscle metabolism and contraction in high level athletes.
Methods: Muscle biopsies were collected from of three distinct phenotypes; endurance athletes ( = 29), power athletes ( = 17), and untrained non-athletes ( = 63).
Achilles tendon rupture necessitates rapid tendon reattachment to reinstate plantar flexion before affected muscles deteriorate through muscle fiber atrophy and transformation. The implicated process may involve alterations in sarcolemmal sites of myofibril attachment (costameres), which control myofibrillogenesis via a mechano-regulated mechanism through integrin-associated focal adhesion kinase (FAK). We assessed the contribution of FAK to alterations in fiber type composition and expression of costamere-associated structural proteins, the phosphorylation status of Y397-FAK and downstream mTOR/JNK-P70S6K hypertrophy signaling in rat soleus muscle after Achilles tenotomy and tendon repair.
View Article and Find Full Text PDFColorectal cancer (CRC) is one of the leading causes of cancer-related deaths worldwide and the need for novel biomarkers and therapeutic strategies to improve diagnosis and surveillance is obvious. This study aims to identify β -integrin (ITGB6) as a novel serum tumor marker for diagnosis, prognosis, and surveillance of CRC. ITGB6 serum levels were validated in retro- and prospective CRC patient cohorts.
View Article and Find Full Text PDFWe investigated molecular and cellular parameters which set metabolic and mechanical functioning of knee extensor muscles in the operated and contralateral control leg of 9 patients with a chronically insufficient anterior cruciate ligament (ACL; 26.6 ± 8.3 years, 8 males, 1 female) after open reconstructive surgery (week 0), after ambulant physiotherapy under cast immobilization (week 9), succeeding rehabilitation training (up to week 26), and subsequent voluntary physical activity (week 260).
View Article and Find Full Text PDFTo understand the molecular basis of neuronal excitation in the mammalian olfactory system, we conducted a systematic analysis of the organization of voltage-gated sodium (Na) channel subunits in the main olfactory epithelium (MOE) and vomeronasal organ (VNO) of adult mice. We also analyzed changes in Na channel expression during development in these two systems and during regeneration of the MOE. Quantitative PCR shows that Na1.
View Article and Find Full Text PDFBackground/aims: The protein tyrosine phosphatase non-receptor type 2 (PTPN2) is known to mediate susceptibility to inflammatory bowel diseases. Cell culture experiments suggest that PTPN2 influences barrier function, autophagy and secretion of pro-inflammatory cytokines. PTPN2 knockout mice die a few weeks after birth due to systemic inflammation, emphasizing the importance of this phosphatase in inflammatory processes.
View Article and Find Full Text PDFInflammasomes form as the result of the intracellular presence of danger-associated molecular patterns and mediate the release of active IL-1β, which influences a variety of inflammatory responses. Excessive inflammasome activation results in severe inflammatory conditions, but physiological IL-1β secretion is necessary for intestinal homeostasis. Here, we have described a mechanism of NLRP3 inflammasome regulation by tyrosine phosphorylation of NLRP3 at Tyr861.
View Article and Find Full Text PDFBackground/aims: Genetic polymorphisms within the gene locus encoding protein tyrosine phosphatase non-receptor type 2 (PTPN2) have been associated with inflammatory bowel disease (IBD). A recent study demonstrated that PTPN2 regulates ER stress signalling in pancreatic β-cells. Therefore, we investigated whether PTPN2 regulates ER stress pathways, apoptosis and cytokine secretion in human intestinal epithelial cells (IECs) and monocytes.
View Article and Find Full Text PDFBackground: Spermidine is a dietary polyamine that is able to activate protein tyrosine phosphatase non-receptor type 2 (PTPN2). As PTPN2 is known to be a negative regulator of interferon-gamma (IFN-γ)-induced responses, and IFN-γ stimulation of immune cells is a critical process in the immunopathology of inflammatory bowel disease (IBD), we wished to explore the potential of spermidine for reducing pro-inflammatory effects in vitro and in vivo.
Methods: Human THP-1 monocytes were treated with IFN-γ and/or spermidine.