Neuronal mechanobiology plays a vital function in brain development and homeostasis with an essential role in neuronal maturation, pathfinding, and differentiation but is also crucial for understanding brain pathology. In this study, we constructed an in vitro system to assess neuronal responses to cyclic strain as a mechanical signal. The selected strain amplitudes mimicked physiological as well as pathological conditions. By subjecting embryonic neuronal cells to cyclic uniaxial strain we could steer the direction of neuronal outgrowth perpendicular to strain direction for all applied amplitudes. A long-term analysis proved maintained growth direction. Moreover, stretched neurons showed an enhanced length, growth, and formation of nascent side branches with most elevated growth rates subsequent to physiological straining. Application of cyclic strain to already formed neurites identified retraction bulbs with destabilized microtubule structures as spontaneous responses. Importantly, neurons were able to adapt to the mechanical signals without induction of cell death and showed a triggered growth behavior when compared to unstretched neurons. The data suggest that cyclic strain plays a critical role in neuronal development.
Breast cancer is a multifactorial disease classified by several sub-types which differ from each other by risk factors, specific molecular promoters and severity of outcomes. Tumour aggressiveness and metastatic disease are the key determinants of breast cancer outcomes. Tumour cell ability to degrade the extracellular matrix and to be motile is the hallmark of invasion and essential step in a development of breast cancer metastatic disease. Therefore, a coordinated action between cell motility and ability to degrade the extracellular matrix is currently under extensive investigation focused on molecular targets for both diagnostic and therapeutic purposes. Contextually, our current study was dedicated to patient stratification utilising MMP-9 serum activity levels and RhoA expression patterns measured in circulating leucocytes. Biomarker patterns were "masked" in non-stratified patient groups. In contrast, the multiparametric stratification approach led to highly improved clinical utility of biomarker patterns. Presented stratification system is recommended for population screening as a cost-effective non-invasive approach to facilitate predictive diagnostics of breast cancer predisposition, pre-lesions and early stages, when the pathology can be effectively prevented or cured. Proposed approach might be particularly useful for early and predictive breast cancer diagnostics applied to certain phenotypes such as premenopausal rather than postmenopausal women, women with dense breast tissue, where highly increased RhoA/MMPs activities are utilised for effective proteolysis of the matrix and cancer cell migration into dense matrices, as well as for breast cancer of unclear origin such as particularly aggressive triple-negative sub-type.
In the brain, neural stem cells (NSC) are tightly regulated by external signals and biophysical cues mediated by the local microenvironment or “niche.” In particular, the influence of tissue elasticity, known to fundamentally affect the function of various cell types in the body, on NSC remains poorly understood. We, accordingly, aimed to characterize the effects of elastic substrates on critical NSC functions. Primary rat NSC were grown as monolayers on polydimethylsiloxane‐ (PDMS‐) based gels. PDMS‐coated cell culture plates, simulating the physiological microenvironment of the living brain, were generated in various degrees of elasticity, ranging from 1 to 50 kPa; additionally, results were compared with regular glass plates as usually used in cell culture work. Survival of NSC on the PDMS‐based substrates was unimpaired. The proliferation rate on 1 kPa PDMS decreased by 45% compared with stiffer PMDS substrates of 50 kPa (p < 0.05) whereas expression of cyclin‐dependent kinase inhibitor 1B/p27Kip1 increased more than two fold (p < 0.01), suggesting NSC quiescence. NSC differentiation was accelerated on softer substrates and favored the generation of neurons (42% neurons on 1 kPa PDMS vs. 25% on 50 kPa PDMS; p < 0.05). Neurons generated on 1 kPa PDMS showed 29% longer neurites compared with those on stiffer PDMS substrates (p < 0.05), suggesting optimized neuronal maturation and an accelerated generation of neuronal networks. Data show that primary NSC are significantly affected by the mechanical properties of their microenvironment. Culturing NSC on a substrate of brain‐like elasticity keeps them in their physiological, quiescent state and increases their neurogenic potential.
Predictive preventive personalized medicine Liver cancer is the fifth most common form of cancer worldwide [1], with an incidence rate almost equals the mortality rate and ranks 3 rd among causes of cancer related death [2]. The coexistence of two life threatening conditions, cancer and liver cirrhosis makes the staging challenging. However, there are some staging systems, e.g. the Barcelona staging system for Hepatocellular carcinoma (HCC) [3], that suggest treatment options and management. Whereas diagnosis in early stages gives hope for a curative outcome, the treatment regime for around 80 % [2] of the patients classified as severe stages only gears towards palliation [4]. An intra-arterial radiation approach, radioembolisation (RE) is ubiquitously applied as one of palliative approaches. Although, in general RE shows promising results in intermediate and advanced stage HCC [5], individual treatment outcomes are currently unpredictable. Corresponding stratification criteria are still unclear. We hypothesised that individual radioresistance/radiosensitivity may play a crucial role in treatment response towards RE strongly influencing individual outcomes. Further, HCC represents a highly heterogeneous group of patients which requires patient stratification according to clear criteria for treatment algorithms to be applied individually. Multilevel diagnostic approach (MLDA) is considered helpful to set-up optimal predictive and prognostic biomarker panel for individualised application of radioembolisation. Besides comprehensive medical imaging, our MLDA includes non-invasive multi-omics and sub-cellular imaging. Individual patient profiles are expected to give a clue to targeting shifted molecular pathways, individual RE susceptibility, treatment response. Hence, a dysregulation of the detoxification pathway (SOD2/Catalase) might indicate possible adverse effects of RE, and highly increased systemic activities of matrix metalloproteinases indicate an enhanced tumour aggressiveness and provide insights into molecular mechanisms/targets. Consequently, an optimal set-up of predictive and prognostic biomarker panels may lead to the changed treatment paradigm from untargeted "treat and wait" to the cost-effective predictive, preventive and personalised approach, improving the life quality and life expectancy of HCC patients. Keywords: Market access, Value, Strategy, Companion diagnostics, Cost-effectiveness, Reimbursement, Health technology assessment, Economic models, Predictive preventive personalized medicine Achieving and sustaining seamless "drug -companion diagnostic" market access requires a sound strategy throughout a product life cycle, which enables timely creation, substantiation and communication of value to key stakeholders [1, 2]. The study aims at understanding the root-cause of market access inefficiencies of companies by gazing at the "Rx-CDx" co-development process through the prism of "value", and developing a perfect co-development scenario based on the literature review and discussions with the ...
Microglia-the brain's primary immune cells-exert a tightly regulated cascade of proand anti-inflammatory effects upon brain pathology, either promoting regeneration or neurodegeneration. Therefore, harnessing microglia emerges as a potential therapeutic concept in neurological research. Recent studies suggest that-besides being affected by chemokines and cytokines-various cell entities in the brain relevantly respond to the mechanical properties of their microenvironment. For example, we lately reported considerable effects of elasticity on neural stem cells, regarding quiescence and differentiation potential. However, the effects of elasticity on microglia remain to be explored.Under the hypothesis that the elasticity of the microenvironment affects key characteristics and functions of microglia, we established an in vitro model of primary rat microglia grown in a polydimethylsiloxane (PDMS) elastomer-based cell culture system. This way, we simulated the brain's physiological elasticity range and compared it to supraphysiological stiffer PDMS controls. We assessed functional parameters of microglia under "resting" conditions, as well as when polarized towards a pro-inflammatory phenotype (M1) by lipopolysaccharide (LPS), or an anti-inflammatory phenotype (M2) by interleukin-4 (IL-4). Microglia viability was unimpaired on soft substrates, but we found various significant effects with a more than twofold increase in microglia proliferation on soft substrate elasticities mimicking the brain (relative to PDMS controls). Furthermore, soft substrates promoted the expression of the activation marker vimentin in microglia. Moreover, the M2-marker CD206 was upregulated in parallel to an increase in the secretion of Insulin-Like Growth Factor-1 (IGF-1). The upregulation of CD206 was abolished by blockage of stretch-dependent chloride channels. Our data suggest that the cultivation of microglia on substrates of brain-like elasticity promotes a basic anti-inflammatory activation state via stretch-dependent chloride
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