Age-related changes in the energy of human mesenchymal stem cells

Aging is a physiological process that leads to a higher risk for the most devastating diseases. There are a number of theories of human aging proposed, and many of them are directly or indirectly linked to mitochondria. Here, we used mesenchymal stem cells (MSCs) from young and older donors to study age-related changes in mitochondrial metabolism. We have found that aging in MSCs is associated with a decrease in mitochondrial membrane potential and lower NADH levels in mitochondria. Mitochondrial DNA content is higher in aged MSCs, but the overall mitochondrial mass is decreased due to increased rates of mitophagy. Despite the higher level of ATP in aged cells, a higher rate of ATP consumption renders them more vulnerable to energy deprivation compared to younger cells. Changes in mitochondrial metabolism in aged MSCs activate the overproduction of reactive oxygen species in mitochondria which is compensated by a higher level of the endogenous antioxidant glutathione. Thus, energy metabolism and redox state are the drivers for the aging of MSCs/mesenchymal stromal cells

Mitochondrial dysfunction in Parkinsonian mesenchymal stem cells impairs differentiation

Sporadic cases account for 90-95% of all patients with Parkinson's Disease (PD). Atypical Parkinsonism comprises approximately 20% of all patients with parkinsonism. Progressive Supranuclear Palsy (PSP) belongs to the atypical parkinsonian diseases and is histopathologically classified as a tauopathy. Here, we report that mesenchymal stem cells (MSCs) derived from the bone marrow of patients with PSP exhibit mitochondrial dysfunction in the form of decreased membrane potential and inhibited NADH-dependent respiration. Furthermore, mitochondrial dysfunction in PSP-MSCs led to a significant increase in mitochondrial ROS generation and oxidative stress, which resulted in decrease of major cellular antioxidant GSH. Additionally, higher basal rate of mitochondrial degradation and lower levels of biogenesis were found in PSP-MSCs, together leading to a reduction in mitochondrial mass. This phenotype was biologically relevant to MSC stemness properties, as it heavily impaired their differentiation into adipocytes, which mostly rely on mitochondrial metabolism for their bioenergetic demand. The defect in adipogenic differentiation was detected as a significant impairment of intracellular lipid droplet formation in PSP-MSCs. This result was corroborated at the transcriptional level by a significant reduction of PPARγ and FABP4 expression, two key genes involved in the adipogenic molecular network. Our findings in PSP-MSCs provide new insights into the etiology of 'idiopathic' parkinsonism, and confirm that mitochondrial dysfunction is important to the development of parkinsonism, independent of the type of the cell

Extracellular vesicles as graft biomarkers to address lung transplantation outcome

Lung transplantation is the last therapeutic option for end-stage pulmonary failure. Yet, clinical complications may rise after transplantation, such as primary grafts dysfunction (PGD) or chronic lung allograft dysfunction (CLAD). Current clinical parameters have failed to assess the quality of the graft and to predict transplantation outcome. Extracorporeal photopheresis (ECP) is a treatment for graft-versus-host disease. Peripheral blood white blood cells (WBC) are isolated, exposed to 8-methoxypsoralen photosensitizing agent, and subsequently treated with ultraviolet radiation before reinfusion into the patient, causing massive WBC apoptosis. Our working hypothesis is that extracellular vesicles (EV) produced by either the pre-transplantation organ (donor) or host (recipient) could be non-invasive biomarkers to evaluate tissue damage at the cellular level and to monitor organ engraftment

Removing exogenous information using pedigree data

Management of certain populations requires the preservation of its pure genetic background. When, for different reasons, undesired alleles are introduced, the original genetic conformation must be recovered. The present study tested, through computer simulations, the power of recovery (the ability for removing the foreign information) from genealogical data. Simulated scenarios comprised different numbers of exogenous individuals taking partofthe founder population anddifferent numbers of unmanaged generations before the removal program started. Strategies were based on variables arising from classical pedigree analyses such as founders? contribution and partial coancestry. The ef?ciency of the different strategies was measured as the proportion of native genetic information remaining in the population. Consequences on the inbreeding and coancestry levels of the population were also evaluated. Minimisation of the exogenous founders? contributions was the most powerful method, removing the largest amount of genetic information in just one generation.However, as a side effect, it led to the highest values of inbreeding. Scenarios with a large amount of initial exogenous alleles (i.e. high percentage of non native founders), or many generations of mixing became very dif?cult to recover, pointing out the importance of being careful about introgression events in populatio

FOXP1 circular RNA sustains mesenchymal stem cell identity via microRNA inhibition

Stem cell identity and plasticity are controlled by master regulatory genes and complex circuits also involving non-coding RNAs. Circular RNAs (circRNAs) are a class of RNAs generated from protein-coding genes by backsplicing, resulting in stable RNA structures devoid of free 5' and 3' ends. Little is known of the mechanisms of action of circRNAs, let alone in stem cell biology. In this study, for the first time, we determined that a circRNA controls mesenchymal stem cell (MSC) identity and differentiation. High-throughput MSC expression profiling from different tissues revealed a large number of expressed circRNAs. Among those, circFOXP1 was enriched in MSCs compared to differentiated mesodermal derivatives. Silencing of circFOXP1 dramatically impaired MSC differentiation in culture and in vivo. Furthermore, we demonstrated a direct interaction between circFOXP1 and miR-17-3p/miR-127-5p, which results in the modulation of non-canonical Wnt and EGFR pathways. Finally, we addressed the interplay between canonical and non-canonical Wnt pathways. Reprogramming to pluripotency of MSCs reduced circFOXP1 and non-canonical Wnt, whereas canonical Wnt was boosted. The opposing effect was observed during generation of MSCs from human pluripotent stem cells. Our results provide unprecedented evidence for a regulatory role for circFOXP1 as a gatekeeper of pivotal stem cell molecular networks

Are Farm-Reared Quails for Game Restocking Really Common Quails (Coturnix coturnix)?: A Genetic Approach

The common quail (Coturnix coturnix) is a popular game species for which restocking with farm-reared individuals is a common practice. In some areas, the number of released quails greatly surpasses the number of wild breeding common quail. However, common quail are difficult to raise in captivity and this casts suspicion about a possible hybrid origin of the farmed individuals from crosses with domestic Japanese quail (C. japonica). In this study we used a panel of autosomal microsatellite markers to characterize the genetic origin of quails reared for hunting purposes in game farms in Spain and of quails from an experimental game farm which was founded with hybrids that have been systematically backcrossed with wild common quails. The genotypes of these quail were compared to those of wild common quail and domestic strains of Japanese quail. Our results show that more than 85% of the game farm birds were not common quail but had domestic Japanese quail ancestry. In the experimental farm a larger proportion of individuals could not be clearly separated from pure common quails. We conclude that the majority of quail sold for restocking purposes were not common quail. Genetic monitoring of individuals raised for restocking is indispensable as the massive release of farm-reared hybrids could represent a severe threat for the long term survival of the native species

Large-scale production of extracellular vesicles: Report on the “massivEVs” ISEV workshop

Extracellular vesicles (EVs) large-scale production is a crucial point for the translation of EVs from discovery to application of EV-based products. In October 2021, the International Society for Extracellular Vesicles (ISEV), along with support by the FET-OPEN projects, “The Extracellular Vesicle Foundry” (evFOUNDRY) and “Extracellular vesicles from a natural source for tailor-made nanomaterials” (VES4US), organized a workshop entitled “massivEVs” to discuss the potential challenges for translation of EV-based products. This report gives an overview of the topics discussed during “massivEVs”, the most important points raised, and the points of consensus reached after discussion among academia and industry representatives. Overall, the review of the existing EV manufacturing, upscaling challenges and directions for their resolution highlighted in the workshop painted an optimistic future for the expanding EV field

Current reproductive isolation between ancestors of natural hybrids in Bacillus stick insects (Insecta: Phasmatodea)

Interspecific hybrids raise a variety of developmental, reproductive, and evolutionary issues. In Sicily, geographically and chronologically distinct hybridizations between the highly differentiated Bacillus rossius and B. grandii have produced hybridogenetic strains and clonal parthenogenetic species. In northern Sicily, all-female populations of facultatively parthenogenetic B. rossius and bisexual B. grandii benazzii co- occur and we could test their current hybridization through electrophoretic marker analyses; control crosses with allopatric males were also carried out. Hybrid female progeny percentages ranged from 0 to 74 being fewer in egg batches laid by parthenogenetic mothers than in those of amphimictic females; no difference was noticed between sympatric and allopatric pairs. F1 hybrids of both sexes proved sterile; although some eggs started cleaving, no hemiclonal or clonal progeny hatched, only rare androgenetics being obtained. In currently produced hybrids a complete disruption of gametogenesis occurs, so that genetic constraints between parental taxa appear stronger now than in the past, most likely the result of ancestor evolution

Detecting introgressive hybridisation in rock partridge populations (Alectoris graeca) in Greece through Bayesian admixture analyses of multilocus genotypes

The nominal subspecies of rock partridge (Alectoris graeca graeca) is widely distributed in Greece, where populations are declining due to over-hunting and habitat changes. Captive-reared chukars (A. chukar) have been massively released throughout the country, raising fear that introgressive hybridisation might have disrupted local adaptations leading to further population declines. In this study we used mtDNA control-region sequences and Bayesian admixture analyses of multilocus genotypes determined at eight microsatellite loci, to assess the extent of introgressive hybridisation in 319 wild rock partridges collected in Greece. A neighbour-joining tree split the mtDNA haplotypes into three strongly supported clades, corresponding to rock, red-legged (A. rufa) and chukar partridges. We did not detect any case of maternal introgression. In contrast, admixture analyses of microsatellite genotypes identified from four to 28 putative hybrids (according to different assignment criteria), corresponding to 1.2-8.8% of the samples, which were widespread throughout all the country. Power and limits of admixture analyses were assessed using simulated hybrid genotypes, which revealed that a small number of markers can detect all first and second generation hybrids (F-1 and F-2), and up to 90% of the first generation backrossess. Thus, the true proportion of recently introgressed rock partridges in Greece might be ca. 20%. These findings indicate that introgressive hybridisation is widespread, suggesting that released captive-bred partridges have reproduced and hybridised in nature polluting the gene pool of wild rock partridge populations in Greece

Carbon dots conjugated to SN38 for improved colorectal anticancer therapy

: Irinotecan (CTP-11) is one of the standard therapies for colorectal cancer (CRC). CTP-11 is enzymatically converted to the hydrophobic 7-ethyl-10-hydroxycamptothecin (SN38), a one hundred-fold more active metabolite. Conjugation of hydrophobic anticancer drugs to nanomaterials is a strategy to improve their solubility, efficacy, and selectivity. Carbon dots (CDs) have garnered interest for their small sizes (<10 ​nm), low toxicity, high water solubility, and bright fluorescence. This paper describes the use of CDs to improve drug vehiculation, stability, and chemotherapeutic efficiency of SN38 through a direct intracellular uptake in CRC. The covalent conjugation of SN38 to CDs via a carbamate bond provides a CD-SN38 hybrid material for slow, sustained, and pH-responsive drug release. CD-SN38 successfully penetrates the CRC cells with a release in the nucleus affecting first the cell cycle and then the cytoskeleton. Moreover, CD-SN38 leads to a deregulation of the extracellular matrix (ECM), one of the major components of the cancer niche considered a possible target therapy for reducing the cancer progression. This work shows the combined therapeutic and imaging potential of CD-based hybrid materials for the treatment of CRC. Future efforts for targeted therapy of chronic diseases characterized by altered ECM deposition, such as chronic kidney disease and chronic allograft nephropathy in kidney transplant patients are envisaged