Biofabrication of in situ self assembled 3D cell cultures in a weightlessness environment generated using magnetic levitation

Magnetic levitation though negative magnetophoresis is a novel technology to simulate weightlessness and has recently found applications in material and biological sciences. Yet little is known about the ability of the magnetic levitation system to facilitate biofabrication of in situ three dimensional (3D) cellular structures. Here, we optimized a magnetic levitation though negative magnetophoresis protocol appropriate for long term levitated cell culture and developed an in situ 3D cellular assembly model with controlled cluster size and cellular pattern under simulated weightlessness. The developed strategy outlines a potential basis for the study of weightlessness on 3D living structures and with the opportunity for real-time imaging that is not possible with current ground-based simulated weightlessness techniques. The low-cost technique presented here may offer a wide range of biomedical applications in several research fields, including mechanobiology, drug discovery and developmental biology.Scientific and Technological Research Council of Turkey (215S862

Microgravity and Musculoskeletal Health: What Strategies Should Be Used for a Great Challenge?

: Space colonization represents the most insidious challenge for mankind, as numerous obstacles affect the success of space missions. Specifically, the absence of gravitational forces leads to systemic physiological alterations, with particular emphasis on the musculoskeletal system. Indeed, astronauts exposed to spaceflight are known to report a significant impairment of bone microarchitecture and muscle mass, conditions clinically defined as osteoporosis and sarcopenia. In this context, space medicine assumes a crucial position, as the development of strategies to prevent and/or counteract weightlessness-induced alterations appears to be necessary. Furthermore, the opportunity to study the biological effects induced by weightlessness could provide valuable information regarding adaptations to spaceflight and suggest potential treatments that can preserve musculoskeletal health under microgravity conditions. Noteworthy, improving knowledge about the latest scientific findings in this field of research is crucial, as is thoroughly investigating the mechanisms underlying biological adaptations to microgravity and searching for innovative solutions to counter spaceflight-induced damage. Therefore, this narrative study review, performed using the MEDLINE and Google Scholar databases, aims to summarize the most recent evidence regarding the effects of real and simulated microgravity on the musculoskeletal system and to discuss the effectiveness of the main defence strategies used in both real and experimental settings

Low Intensity Vibrations Restore Nuclear YAP Levels and Acute YAP Nuclear Shuttling in Mesenchymal Stem Cells Subjected to Simulated Microgravity

The bone deterioration that astronauts experience in microgravity environments is known to occur in response to the lack of gravity-based tissue stress. Mechanical forces are crucial to maintain healthy bone mass by regulating the function of bone-making osteoblasts as well as the proliferation and differentiation of their progenitors, mesenchymal stem cells (MSC) which replenish osteoblastic cells. Regulation of proliferative function of MSCs in response to mechanical force is in part controlled by the “mechanotransducer” protein YAP (Yes-associated protein) which is shuttled into the nucleus in response to mechanical challenge to induce gene expression necessary for cell proliferation. Our group had recently reported that altered gravity conditions under simulated microgravity (SMG) decreases proliferation of MSCs and that application of daily low intensity vibrations (LIV) during SMG reverses this effect on proliferation. While these findings suggest that LIV may be a promising countermeasure for altered loading, the specific SMG and LIV effects on YAP mechanosignaling are unknown. Therefore, here we tested the effects of SMG and daily LIV treatment on basal nuclear YAP levels as well as on the acute YAP nuclear entry in response to both mechanical and soluble factors in MSCs. MSCs subjected to 72h of SMG, despite decreased nuclear YAP levels across all groups, responded to both LIV and Lysophosphohaditic acid (LPA) treatments by increasing nuclear YAP levels within 6hrs by 49.52% and 87.34%, respectively. Additionally, daily LIV restored the basal decrease seen in SMG as well as nuclear YAP levels as well as restored in part the YAP nuclear entry response to subsequently applied acute LIV and LPA treatments. These results show that rescue of basal YAP levels by LIV may explain previously found proliferative effects of MSCs under SMG and demonstrates that daily LIV is capable of alleviating the inhibition caused by SMG of YAP nuclear shuttling in response to subsequent mechanical and soluble challenge

Mast Cells and Lipid Cross-Talk in Skin Inflammation

Atopic dermatitis (AD) is an inflammatory skin disease whose pathogenic mechanisms remain unclear. Using a validated human AD-like mouse model, we observed that skin remodeling started at a pre-symptomatic stage of AD that included cellular infiltration of the hypodermis, accompanied with activated/degranulated mast cells (MC). Local MC activation was quantified using a novel method of computer-assisted image analysis we developed and reported. Using a variation of this method, we defined morphometric parameters allowing for quantitation rather than scoring of cellular infiltration. Cell recruitment correlated with MC activation, chemokine production and increased levels of sphingolipid sphingosine-1-phosphate (S1P), produced by sphingosine kinase-1 (SphK1). MC or SphK1 deficiency significantly hindered early AD inflammation. Chronic AD features skin barrier dysfunction leading to skin lesions due to decreased lipid ceramide (CER) content. Interestingly, local CER species C16 and C24 were significantly increased in pre-symptomatic AD. Accordingly, skin CER synthase (CerS, CER synthesis) CerS4, 5 and 6 mRNA mRNA levels were statistically augmented. Because of the overall proapoptotic functions of CER, we next measured local cleaved/activated caspase 3 levels, the executioner caspase in apoptosis. Skin cleaved caspase 3/apoptosis was significantly augmented in early AD and correlated with increased endoplasmic reticulum (ER) stress-related molecular players. To substantiate the importance of MC in ER stress-induced apoptosis, CER profiling was similarly conducted in treated skin samples collected from MC-deficient mice. MC deficiency prevented CER increase and local apoptosis that were restored following MC reconstitution. Epigenetic regulation of the molecular pathways that drive AD is unknown. We identified and validated a microRNA triad 34a-485-486 whose downregulation promoted the AD-related pathogenic pathways we have unraveled. We conclude that MC may initiate AD by driving early skin remodeling and cell recruitment through local chemokine and S1P production and CER-elicited apoptosis. Moreover, the down-regulation of a miRNA triad de-represses these key players of AD pathogenesis. Targeting these pre-symptomatic effector mechanisms may offer new prophylactic strategies for AD whose treatment remains a clinical challenge

Life Sciences Program Tasks and Bibliography for FY 1997

This document includes information on all peer reviewed projects funded by the Office of Life and Microgravity Sciences and Applications, Life Sciences Division during fiscal year 1997. This document will be published annually and made available to scientists in the space life sciences field both as a hard copy and as an interactive internet web page

Life Sciences Program Tasks and Bibliography for FY 1996

This document includes information on all peer reviewed projects funded by the Office of Life and Microgravity Sciences and Applications, Life Sciences Division during fiscal year 1996. This document will be published annually and made available to scientists in the space life sciences field both as a hard copy and as an interactive Internet web page

Life Sciences Program Tasks and Bibliography

This document includes information on all peer reviewed projects funded by the Office of Life and Microgravity Sciences and Applications, Life Sciences Division during fiscal year 1995. Additionally, this inaugural edition of the Task Book includes information for FY 1994 programs. This document will be published annually and made available to scientists in the space life sciences field both as a hard copy and as an interactive Internet web pag