Cell engraftment, survival and integration during transplantation procedures represent the crux of cell-based therapies. Thus, there have been many studies focused on improving cell viability upon implantation. We used severe oxidative stress to select for a mouse mesoangioblast subpopulation in vitro and found that this subpopulation retained self-renewal and myogenic differentiation capacities while notably enhancing cell survival, proliferation and migration relative to unselected cells. Additionally, this subpopulation of cells presented different resistance and recovery properties upon oxidative stress treatment, demonstrating select advantages over parental mesoangioblasts in our experimental analysis. Specifically, the cells were resistant to oxidative environments, demonstrating survival, continuous self-renewal and improved migration capability. The primary outcome of the selected cells was determined in in vivo experiments in which immunocompromised dystrophic mice were injected intramuscularly in the tibialis anterior with selected or non-selected mesoangioblasts. Resistant mesoangioblasts exhibited markedly enhanced survival and integration into the host skeletal muscle, accounting for a more than 70% increase in engraftment compared with that of the unselected mesoangioblast cell population and leading to remarkable muscle recovery. Thus, the positive effects of sorting on mesoangioblast cell behaviour in vitro and in vivo suggest that a selection step involving oxidative stress preconditioning may provide a novel methodology to select for resistant cells for use in regenerative tissue applications to prevent high mortality rates upon transplantation.

Aims The EURO-ENDO registry aimed to study the management and outcomes of patients with infective endocarditis (IE). Methods and results Prospective cohort of 3116 adult patients (2470 from Europe, 646 from non-ESC countries), admitted to 156 hospitals in 40 countries between January 2016 and March 2018 with a diagnosis of IE based on ESC 2015 diagnostic criteria. Clinical, biological, microbiological, and imaging [echocardiography, computed tomography (CT) scan, 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT)] data were collected. Infective endocarditis was native (NVE) in 1764 (56.6%) patients, prosthetic (PVIE) in 939 (30.1%), and device-related (CDRIE) in 308 (9.9%). Infective endocarditis was community-acquired in 2046 (65.66%) patients. Microorganisms involved were staphylococci in 1085 (44.1%) patients, oral streptococci in 304 (12.3%), enterococci in 390 (15.8%), and Streptococcus gallolyticus in 162 (6.6%). 18F-fluorodeoxyglucose positron emission tomography/computed tomography was performed in 518 (16.6%) patients and presented with cardiac uptake (major criterion) in 222 (42.9%) patients, with a better sensitivity in PVIE (66.8%) than in NVE (28.0%) and CDRIE (16.3%). Embolic events occurred in 20.6% of patients, and were significantly associated with tricuspid or pulmonary IE, presence of a vegetation and Staphylococcus aureus IE. According to ESC guidelines, cardiac surgery was indicated in 2160 (69.3%) patients, but finally performed in only 1596 (73.9%) of them. In-hospital death occurred in 532 (17.1%) patients and was more frequent in PVIE. Independent predictors of mortality were Charlson index, creatinine > 2 mg/dL, congestive heart failure, vegetation length > 10 mm, cerebral complications, abscess, and failure to undertake surgery when indicated. Conclusion Infective endocarditis is still a life-threatening disease with frequent lethal outcome despite profound changes in its clinical, microbiological, imaging, and therapeutic profiles.

Germ cells are sensitive to genotoxins, and ovarian failure and infertility are major side effects of chemotherapy in young patients with cancer. Here we describe the c-Abl-TAp63 pathway activated by chemotherapeutic DNA-damaging drugs in model human cell lines and in mouse oocytes and its role in cell death. In cell lines, upon cisplatin treatment, c-Abl phosphorylates TAp63 on specific tyrosine residues. Such modifications affect p63 stability and induce a p63-dependent activation of proapoptotic promoters. Similarly, in oocytes, cisplatin rapidly promotes TAp63 accumulation and eventually cell death. Treatment with the c-Abl kinase inhibitor imatinib counteracts these cisplatin-induced effects. Taken together, these data support a model in which signals initiated by DNA double-strand breaks are detected by c-Abl, which, through its kinase activity, modulates the p63 transcriptional output. Moreover, they suggest a new use for imatinib, aimed at preserving oocytes of the follicle reserve during chemotherapeutic treatments.

We present a new strategy for the fabrication of artificial skeletal muscle tissue with functional morphologies based on an innovative 3D bioprinting approach. The methodology is based on a microfluidic printing head coupled to a co-axial needle extruder for high-resolution 3D bioprinting of hydrogel fibers laden with muscle precursor cells (C2C12). To promote myogenic differentiation, we formulated a tailored bioink with a photocurable semi-synthetic biopolymer (PEG-Fibrinogen) encapsulating cells into 3D constructs composed of aligned hydrogel fibers. After 3-5 days of culture, the encapsulated myoblasts started migrating and fusing, forming multinucleated myotubes within the 3D bioprinted fibers. The obtained myotubes showed high degree of alignment along the direction of hydrogel fiber deposition, further revealing maturation, sarcomerogenesis, and functionality. Following subcutaneous implantation in the back of immunocompromised mice, bioprinted constructs generated organized artificial muscle tissue in vivo. Finally, we demonstrate that our microfluidic printing head allows to design three dimensional multi-cellular assemblies with an exquisite compartmentalization of the encapsulated cells. Our results demonstrate an enhanced myogenic differentiation with the formation of parallel aligned long-range myotubes. The approach that we report here represents a robust and valid candidate for the fabrication of macroscopic artificial muscle to scale up skeletal muscle tissue engineering for human clinical application.

Aims: The transcriptional coactivator peroxisome proliferator-activated receptor-c coactivator-1 a (PPARGC1A or PGC-1a) is a powerful controller of cell metabolism and assures the balance between the production and the scavenging of pro-oxidant molecules by coordinating mitochondrial biogenesis and the expression of antioxidants. However, even though a huge amount of data referring to the role of PGC-1a is available, the molecular mechanisms of its regulation at the transcriptional level are not completely understood. In the present report, we aim at characterizing whether the decrease of antioxidant glutathione (GSH) modulates PGC-1a expression and its downstream metabolic pathways. Results: We found that upon GSH shortage, induced either by its chemical depletion or by metabolic stress (i.e., fasting), p53 binds to the PPARGC1A promoter of both human and mouse genes, and this event is positively related to increased PGC-1a expression. This effect was abrogated by inhibiting nitric oxide (NO) synthase or guanylate cyclase, implicating NO/cGMP signaling in such a process. We show that p53-mediated PGC-1a upregulation is directed to potentiate the antioxidant defense through nuclear factor (erythroid-derived 2)-like2 (NFE2L2)-mediated expression of manganese superoxide dismutase (SOD2) and c-glutamylcysteine ligase without modulating mitochondrial biogenesis. Innovation and Conclusions: We outlined a new NO-dependent signaling axis responsible for survival antioxidant response upon mild metabolic stress (fasting) and/or oxidative imbalance (GSH depletion). Such signaling axis could become the cornerstone for new pharmacological or dietary approaches for improving antioxidant response during ageing and human pathologies associated with oxidative stress. Antioxid. Redox Signal. 18, 386-399.