Marcus Krüger

Marcus Krüger
Otto-von-Guericke-Universität Magdeburg | OvGU · Department of Microgravity and Translational Regenerative Medicine

Dr. rer. nat.

About

78
Publications
23,596
Reads
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1,604
Citations
Citations since 2017
74 Research Items
1581 Citations
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Additional affiliations
October 2016 - May 2020
Otto-von-Guericke-Universität Magdeburg
Position
  • Senior Researcher
April 2011 - September 2013
Friedrich-Alexander-University of Erlangen-Nürnberg
Position
  • Lecturer
Description
  • Basic courses and field exercises in botany (characteristics of common flowering plant families, identifying plants using taxonomic keys, diversity and ecology of flowering plants in this region). Extension courses in plant ecology and crop biology.
February 2011 - September 2016
Friedrich-Alexander-University of Erlangen-Nürnberg
Position
  • Research Associate
Education
October 2000 - October 2005
Friedrich-Alexander-University of Erlangen-Nürnberg
Field of study
  • Biology (Microbiology, Botany & Phytogeography, Molecular Plant Physiology, Animal Physiology)

Publications

Publications (78)
Article
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Microgravity in space or simulated by special ground-based devices provides an unusual but unique environment to study and influence tumour cell processes. By investigating thyroid cancer cells in microgravity for nearly 20 years, researchers got insights into tumour biology that had not been possible under normal laboratory conditions: adherently...
Article
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Detachment and the formation of spheroids under microgravity conditions can be observed with various types of intrinsically adherent human cells. In particular, for cancer cells this process mimics metastasis and may provide insights into cancer biology and progression that can be used to identify new drug/target combinations for future therapies....
Article
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BACKGROUND/AIMS: Endothelial cells exposed to the Random Positioning Machine (RPM) reveal three different phenotypes. They grow as a two-dimensional monolayer and form three-dimensional (3D) structures such as spheroids and tubular constructs. As part of the ESA-SPHEROIDS project we want to understand how endothelial cells (ECs) react and adapt to...
Article
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Due to the increasing development of antibiotic resistances in recent years, scientists search intensely for new methods to control bacteria. Photodynamic treatment with porphyrins such as chlorophyll derivatives is one of the most promising methods to handle bacterial infestation, but their use is dependent on illumination and they seem to be more...
Article
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Colistin (polymyxin E) is a membrane-destabilizing antibiotic used against Gram- bacteria. We have recently reported that the outer membrane prevents the uptake of antibacterial chlorophyllin into Gram-negative cells. In this study, we used sub-toxic concentrations of colistin to weaken this barrier for a combination treatment of Escherichia coli a...
Article
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Polyethylenimines (PEIs), a group of polycationic molecules, are known to impair the outer membrane of Gram-negative bacteria and exhibit antimicrobial activity. The outer membrane of Gram-negative strains hinders the uptake of photosensitizer chlorophyllin. In this study, we report chlorophyllin and branched PEI combinations’ activity against Esch...
Article
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Cell death is a fundamental and highly organized biological phenomenon that was long considered nothing more than the inevitable endpoint of life; this is reflected in the meaning of the Greek word, ἀπόπτωσις (“falling leaves from a tree”) [...]
Article
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Cancer is a disease exhibiting uncontrollable cell growth and spreading to other parts of the organism. It is a heavy, worldwide burden for mankind with high morbidity and mortality. Therefore, groundbreaking research and innovations are necessary. Research in space under microgravity (µg) conditions is a novel approach with the potential to fight...
Article
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Prostate cancer metastasis has an enormous impact on the mortality of cancer patients. Factors involved in cancer progression and metastasis are known to be key players in microgravity (µ g )-driven three-dimensional (3D) cancer spheroid formation. We investigated PC-3 prostate cancer cells for 30 min, 2, 4 and 24 h on the random positioning machin...
Article
Introduction : A long-term stay of humans in space causes a large number of well-known health problems and changes in protists and plants. Deep space exploration will increase the time humans or rodents will spend in microgravity (µg). Moreover, they are exposed to cosmic radiation, hypodynamia, and isolation. OMICS investigations will increase our...
Article
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In this review article, we discuss the current state of knowledge in cancer research under real and simulated microgravity conditions and point out further research directions in this field. Outer space is an extremely hostile environment for human life, with radiation, microgravity, and vacuum posing significant hazards. Although the risk for canc...
Article
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As much as space travel and exploration have been a goal since humankind looked up to the stars, the challenges coming with it are manifold and difficult to overcome. Therefore, researching the changes the human organism undergoes following exposure to weightlessness, on a cellular or a physiological level, is imperative to reach the goal of explor...
Article
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Differentiated thyroid cancer (DTC) usually has a good prognosis when treated conventionally with thyroidectomy, radioactive iodine (RAI) and thyroid-stimulating hormone suppression, but some tumors develop a resistance to RAI therapy, requiring alternative treatments. Sorafenib, lenvatinib and cabozantinib are multikinase inhibitors (MKIs) approve...
Article
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A spaceflight to the International Space Station (ISS) is a dream of many researchers. We had the chance to investigate the effect of real microgravity (CellBox-2 Space mission) on the transcriptome and proteome of FTC-133 human follicular thyroid cancer cells (TCC). The cells had been sent to the ISS by a Falcon 9 rocket of SpaceX CRS-13 from Cape...
Article
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The objective of this review is to give an overview of the pathophysiological effects of the Coronavirus Disease 2019 (COVID‐19) in relation to hypertension (HT), with a focus on the Renin–Angiotensin–Aldosterone System (RAAS) and the MAS receptor. HT is a multifactorial disease and a public health burden, as it is a risk factor for diseases like s...
Article
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Functioning as the outermost self-renewing protective layer of the human organism, skin protects against a multitude of harmful biological and physical stimuli. Consisting of ectodermal, mesenchymal, and neural crest-derived cell lineages, tissue homeostasis, and signal transduction are finely tuned through the interplay of various pathways. A heal...
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In this study, we evaluated changes in focal adhesions (FAs) in two types of breast cancer cell (BCC) lines (differentiated MCF-7 and the triple-negative MDA-MB-231 cell line) exposed to simulated microgravity (s-μg) created by a random positioning machine (RPM) for 24 h. After exposure, the BCC changed their growth behavior and exhibited two pheno...
Article
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In lieu of an abstract, this is an excerpt from the first page. Nature provides a unique diversity of primary and secondary metabolites [...]
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Space travel has always been the man’s ultimate destination. With the ability of spaceflight though, came the realization that exposure to microgravity has lasting effects on the human body. To counteract these, many studies were and are undertaken, on multiple levels. Changes in cell growth, gene, and protein expression have been described in diff...
Article
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All life forms have evolved under the constant force of gravity on Earth and developed ways to counterbalance acceleration load. In space, shear forces, buoyance-driven convection, and hydrostatic pressure are nullified or strongly reduced. When subjected to microgravity in space, the equilibrium between cell architecture and the external force is...
Article
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Breast cancer is the leading cause of cancer death in females. The incidence has risen dramatically during recent decades. Dismissed as an "unsolved problem of the last century", breast cancer still represents a health burden with no effective solution identified so far. Microgravity (µg) research might be an unusual method to combat the disease, b...
Article
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Background: Blunt chest (thoracic) trauma (TxT) and haemorrhagic shock with subsequent resuscitation (H/R) induce strong systemic and local inflammatory response, which is closely associated with apoptotic cell loss and subsequently impaired organ function. The underlying mechanisms are not completely understood, therefore, the treatment of patient...
Article
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Living organisms adapt to changing environments using their amazing flexibility to remodel themselves by a process called evolution. Environmental stress causes selective pressure and is associated with genetic and phenotypic shifts for better modifications, maintenance, and functioning of organismal systems. The natural evolution process can be us...
Article
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A spaceflight has enormous influence on the health of space voyagers due to the combined effects of microgravity and cosmic radiation. Known effects of microgravity (μg) on cells are changes in differentiation and growth. Considering the commercialization of spaceflight, future space exploration, and long-term manned flights, research focusing on d...
Article
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The endothelin axis, recognized for its vasoconstrictive action, plays a central role in the pathology of pulmonary arterial hypertension (PAH). Treatment with approved endothelin receptor antagonists (ERAs), such as bosentan, ambrisentan, or macitentan, slow down PAH progression and relieves symptoms. Several findings have indicated that endotheli...
Article
Introduction: Essential hypertension is a significant risk factor for cardiovascular disease, renal disease, and mortality with increasing prevalence. Despite the availability of various antihypertensive agents, hypertension is still poorly controlled. Therefore, new chemical compounds with antihypertensive efficacy need to be developed. The dual a...
Article
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Prostate cancer is one of the leading causes of cancer mortality in men worldwide. An unusual but unique environment for studying tumor cell processes is provided by microgravity, either in space or simulated by ground-based devices like a random positioning machine (RPM). In this study, prostate adenocarcinoma-derived PC-3 cells were cultivated on...
Article
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The renin–angiotensin–aldosterone system (RAAS) has been studied extensively, and with the inclusion of novel components, it has become evident that the system is much more complex than originally anticipated. According to current knowledge, there are two main axes of the RAAS, which counteract each other in terms of vascular control: The classical...
Article
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Vitamin D plays a pivotal role in bone homeostasis and calcium metabolism. However, recent research has indicated additional beneficial effects of vitamin D on the cardiovascular system. This review aims to elucidate if vitamin D can be used as an add-on treatment in coronary artery disease (CAD). Large-scale epidemiological studies have found a si...
Article
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Thyroid cancer is the most common endocrine malignancy. Most thyroid cancer types respond well to conventional treatment consisting of surgery and radioactive iodine (RAI) therapy. Unfortunately, some thyroid cancer types are resistant to surgical and RAI therapy. Multikinase inhibitors (MKIs) can be used in the treatment of advanced refractory thy...
Article
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With the commercialization of spaceflight and the exploration of space, it is important to understand the changes occurring in human cells exposed to real microgravity (r-µg) conditions. We examined the influence of r-µg, simulated microgravity (s-µg, incubator random positioning machine (iRPM)), hypergravity (hyper-g), and vibration (VIB) on tripl...
Article
If monolayers of cancer cells are exposed to microgravity, some of the cells cease adhering to the bottom of a culture flask and join three-dimensional aggregates floating in the culture medium. Searching reasons for this change in phenotype, we performed proteome analyses and learnt that accumulation and posttranslational modification of proteins...
Article
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Licorice, today chiefly utilized as a flavoring additive in tea, tobacco and candy, is one of the oldest used herbs for medicinal purposes and consists of up to 300 active compounds. The main active constituent of licorice is the prodrug glycyrrhizin, which is successively converted to 3β-monoglucuronyl-18β-glycyrrhetinic acid (3MGA) and 18β-glycyr...
Article
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Parabolic flight maneuvers of Novespace’s Airbus A310 ZERO-G produce subsequent phases of hypergravity (about 20 s), microgravity (about 22 s) and another 20 s hypergravity on experiments located in the experiment area of the aircraft. The 29th DLR parabolic flight campaign consisted of four consecutive flight days with thirty-one parabolas each da...
Article
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Background/aims: In articular cartilage, chondrocytes are the predominant cell type. A long-term stay in space can lead to bone loss and cartilage breakdown. Due to the poor regenerative capacity of cartilage, this may impair the crewmembers' mobility and influence mission activities. Beside microgravity other factors such as cosmic radiation and...
Article
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This paper reviews current treatments for renal cell carcinoma/cancer (RCC) with the multikinase inhibitors (MKIs) sorafenib, sunitinib, lenvatinib and axitinib. Furthermore, it compares these drugs regarding progression-free survival, overall survival and adverse effects (AE), with a focus on hypertension. Sorafenib and sunitinib, which are includ...
Article
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The literature suggests morphological alterations and molecular biological changes within the cellular milieu of human cells, exposed to microgravity (µg), as many cell types assemble to multicellular spheroids (MCS). In this study we investigated juvenile normal human dermal fibroblasts (NHDF) grown in simulated µg (s-µg) on a random positioning m...
Article
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Pulmonary arterial hypertension (PAH) is a rare but life‐threatening disease that progresses rapidly and is currently without a cure. Pharmacological treatments aim to slow down disease progression and to reduce symptoms by targeting the prostacyclin, the endothelin or the nitric oxide pathway. Drugs targeting the prostacyclin pathway have been sho...
Article
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Nitric oxide (NO) is a well-known vasodilator produced by the vascular endothelium via the enzyme endothelial nitric oxide synthase (eNOS). The inadequate production of NO has been linked to elevated blood pressure (BP) in both human and animal studies, and might be due to substrate inaccessibility. This review aimed to investigate whether oral adm...
Article
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With the increasing number of spaceflights, it is crucial to understand the changes occurring in human cells exposed to real microgravity (r-µg) conditions. We tested the effect of r-µg on MCF-7 breast cancer cells with the objective to investigate cytoskeletal alterations and early changes in the gene expression of factors belonging to the cytoske...
Article
Current treatment of pulmonary arterial hypertension (PAH) targets three signalling pathways: the nitric oxide (NO) pathway, the endothelin pathway and the prostacyclin pathway. Riociguat is a soluble guanylate cyclase stimulator, acting via the NO pathway in a new way: Unlike other common drugs targeting this pathway (e.g. tadalafil and sildenafil...
Article
This MiniReview reports the current knowledge about treatment of arterial hypertension with the third‐generation beta‐adrenoceptor antagonist (BAA) nebivolol. Furthermore, it reviews the advantages of nebivolol compared to the earlier generation of BAAs with respect to their different pharmacological properties. BAAs are a class of drugs applied fo...
Article
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Endothelial cells (ECs) grow as single layers on the bottom surface of cell culture flasks under normal (1g) culture conditions. In numerous experiments using simulated microgravity we noticed that the ECs formed three-dimensional, tube-like cell aggregates resembling the intima of small, rudimentary blood vessels. The SPHEROIDS project has now sho...
Article
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Cancer is a heavy burden for humans across the world with high morbidity and mortality. Transcription factors including sex determining region Y (SRY)-related high-mobility group (HMG) box (SOX) proteins are thought to be involved in the regulation of specific biological processes. The deregulation of gene expression programs can lead to cancer dev...
Article
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Human cells, when exposed to both real and simulated microgravity (s-µg), form 3D tissue constructs mirroring in vivo architectures (e.g., cartilage, intima constructs, cancer spheroids and others). In this study, we exposed human foetal osteoblast (hFOB 1.19) cells to a Random Positioning Machine (RPM) for 7 days and 14 days, with the purpose of i...
Article
Cancer treatment is an area of continuous improvement. Therapy is becoming more targeted and the use of anti-angiogenic agents in multiple cancers, specifically tyrosine kinase inhibitors (TKIs), has demonstrated prolonged survival outcomes compared with previous drugs. Therefore, they have become a well-established part of the treatment. Despite...
Conference Paper
Full-text available
Despite the fact that astronauts have various health problems in space, the unique culture condition of microgravity (µg) bears the possibility to grow human cells in a three-dimensional (3D) way without scaffolds or matrices. Using facilities like the International Space Station (ISS) or unmanned satellites, we showed that human thyroid cancer cel...
Conference Paper
Full-text available
The cytoskeleton is a highly dynamic structure playing an important role in graviperception and gravisensitivity of cells exposed to microgravity. The cytoskeletal network is closely connected to many cellular processes and functions. The exact mechanisms are mostly unknown. For the first time, we investigated human MCF-7 breast cancer cells in rea...
Conference Paper
Full-text available
When human thyroid carcinoma cells are exposed to microgravity some adherent cells detach from the bottom of the culture flask and grow into floating multicellular spheroids. It is assumed that this process mimics metastasis. The spheroids generated are more complex than a cell monolayer and exhibit properties of small tumours, which cannot be foun...
Article
Full-text available
Thyroid cancer is the most abundant tumor of the endocrine organs. Poorly differentiated thyroid cancer is still difficult to treat. Human cells exposed to long-term real (r-) and simulated (s-) microgravity (µg) revealed morphological alterations and changes in the expression profile of genes involved in several biological processes. The objective...
Article
Introduction: Microgravity (µg) is an extreme stressor for plants, animals and humans and influences biological systems. Humans in space experience various health problems during and after a long-term stay in orbit. Various studies have demonstrated alterations in structural and molecular dynamics within the cellular milieu of plants, bacteria, mi...
Article
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Medullary thyroid cancer (MTC) is a rare malignancy with a poor prognosis. First line therapy is surgery, which is the only curative method of the disease. However, in non-operable cases or with tumor progression and metastases, a systemic treatment is necessary. This form of cancer is often insensitive to conventional chemotherapy, but the use of...
Article
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Human follicular thyroid cancer cells (FTC-133) were sent to space via a sounding rocket during the TEXUS-53 mission to determine the impact of short-term microgravity on these cells. To enable cell culture and fixation in real microgravity, an automated experiment container (EC) was constructed. In order to ensure safe cell culture, cell-chambers...
Article
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Background/aims: Spaceflight negatively influences the function of cartilage tissue in vivo. In vitro human chondrocytes exhibit an altered gene expression of inflammation markers after a two-hour exposure to vibration. Little is known about the impact of long-term vibration on chondrocytes. Methods: Human cartilage cells were exposed for up to...
Article
Persistent pulmonary hypertension in newborn (PPHN) is a serious and possibly fatal syndrome characterized by sustained foetal elevation of pulmonary vascular resistance at birth. PPHN may manifest secondary to other conditions as meconium aspiration syndrome, infection and congenital diaphragmatic hernia. This MiniReview provides the reader with a...
Article
MCF7 human breast cancer cells were cultured under normal gravity (1g) and on a random positioning machine (RPM) preventing sedimentation. After two weeks, adherent 1g‐control and adherent RPM cells (AD) as well as multicellular spheroids (MCS) were harvested. AD and MCS had been exposed to the RPM in the same culture flask. In a subsequent proteom...