Discrete Changes in Glucose Metabolism Define Aging

Aging is a physiological process in which multifactorial processes determine a progressive decline. Several alterations contribute to the aging process, including telomere shortening, oxidative stress, deregulated autophagy and epigenetic modifications. In some cases, these alterations are so linked with the aging process that it is possible predict the age of a person on the basis of the modification of one specific pathway, as proposed by Horwath and his aging clock based on DNA methylation. Because the energy metabolism changes are involved in the aging process, in this work, we propose a new aging clock based on the modifications of glucose catabolism. The biochemical analyses were performed on mononuclear cells isolated from peripheral blood, obtained from a healthy population with an age between 5 and 106 years. In particular, we have evaluated the oxidative phosphorylation function and efficiency, the ATP/AMP ratio, the lactate dehydrogenase activity and the malondialdehyde content. Further, based on these biochemical markers, we developed a machine learning-based mathematical model able to predict the age of an individual with a mean absolute error of approximately 9.7 years. This mathematical model represents a new non-invasive tool to evaluate and define the age of individuals and could be used to evaluate the effects of drugs or other treatments on the early aging or the rejuvenation

Mesenchymal stem cells from preterm to term newborns undergo a significant switch from anaerobic glycolysis to the oxidative phosphorylation

We evaluated the energy metabolism of human mesenchymal stem cells (MSC) isolated from umbilical cord (UC) of preterm (< 37 weeks of gestational age) and term (>= 37 weeks of gestational age) newborns, using MSC from adult bone marrow as control. A metabolic switch has been observed around the 34th week of gestational age from a prevalently anaerobic glycolysis to the oxidative phosphorylation. This metabolic change is associated with the organization of mitochondria reticulum: preterm MSCs presented a scarcely organized mitochondrial reticulum and low expression of proteins involved in the mitochondrial fission/fusion, compared to term MSCs. These changes seem governed by the expression of CLUH, a cytosolic messenger RNA-binding protein involved in the mitochondria biogenesis and distribution inside the cell; in fact, CLUH silencing in term MSC determined a metabolic fingerprint similar to that of preterm MSC. Our study discloses novel information on the production of energy and mitochondrial organization and function, during the passage from fetal to adult life, providing useful information for the management of preterm birth

New insights into synaptic transmission: the depolarization-evoked, Ca2+-dependent release of exosomes from mouse cortical nerve endings

Whether exosomes can be actively released from presynaptic nerve terminals is a matter of debate. To address the point, mouse cortical synaptosomes were incubated under basal and depolarizing (25 mM KCl-enriched medium) conditions, and extracellular vesicles were isolated from the synaptosomal supernatants to be characterized by dynamic light scattering, transmission electron microscopy, Western blot, and flow cytometry analyses. The structural and biochemical analysis unveiled that supernatants contain vesicles that have the size and the shape of exosomes, which were immunopositive for the exosomal markers TSG101, flotillin-1, CD63, and CD9. The marker content increased upon the exposure of nerve terminals to the high-KCl stimulus, consistent with an active release of the exosomes from the depolarized synaptosomes. High KCl-induced depolarization elicits the Ca2+-dependent exocytosis of glutamate. Interestingly, the depolarization-evoked release of exosomes from cortical synaptosomes also occurred in a Ca2+-dependent fashion, since the TSG101, CD63, and CD9 contents in the exosomal fraction isolated from supernatants of depolarized synaptosomes were significantly reduced when omitting external Ca2+ ions. Differently, (\ub1)-baclofen (10 \ub5M), which significantly reduced the glutamate exocytosis, did not affect the amount of exosomal markers, suggesting that the GABAB-mediated mechanism does not control the exosome release. Our findings suggest that the exposure of synaptosomes to a depolarizing stimulus elicits a presynaptic release of exosomes that occurs in a Ca2+-dependent fashion. The insensitivity to the presynaptic GABAB receptors, however, leaves open the question on whether the release of exosomes could be a druggable target for new therapeutic intervention for the cure of synaptopathies

Allogeneic cell transplant expands bone marrow distribution by colonizing previously abandoned areas: An FDG PET/CT analysis

Mechanisms of hematopoietic reconstitution after bone marrow (BM) transplantation remain largely unknown. We applied a computational quantification software application to hybrid 18F-fluorodeoxyglucose positron emission tomography (PET)/computed tomography (CT) images to assess activity and distribution of the hematopoietic system throughout the whole skeleton of recently transplanted patients. Thirty-four patients underwent PET/CT 30 days after either adult stem cell transplantation (allogeneic cell transplantation [ACT]; n = 18) or cord blood transplantation (CBT; n = 16). Our software automatically recognized compact bone volume and trabecular bone volume (IBV) in CT slices. Within IBV, coregistered PET data were extracted to identify the active BM (ABM) from the inactive tissue. Patients were compared with 34 matched controls chosen among a published normalcy database. Whole body ABM increased in ACT and CBT when compared with controls (12.4 \ub1 3 and 12.8 \ub1 6.8 vs 8.1 \ub1 2.6 mL/kg of ideal body weight [IBW], P < .001). In long bones, ABM increased three- and sixfold in CBT and ACT, respectively, compared with controls (0.9 \ub1 0.9 and 1.7 \ub1 2.5 vs 0.3 \ub1 0.3 mL/kg IBW, P < .01). These data document an unexpected distribution of transplanted BM into previously abandoned BM sites

Donor multipotent mesenchymal stromal cells may engraft in pediatric patients given either cord blood or bone marrow transplantation

Objective: Multipotent mesenchymal stromal cells (MSCs) are endowed with multilineage differentiative potential and immunomodulatory properties. It is still a matter of debate whether donor MSCs have sustained engraftment potential in host bone marrow (BM) after allogeneic hematopoietic stem cell transplantation (allo-HSCT). The aim of this study was to analyze the donor/recipient origin of MSCs in children receiving allogeneic either BM or cord blood (CB) transplantation. Methods: Thirty-seven pediatric patients undergoing allo-HSCT for either a malignant or a nonmalignant disorder were enrolled in the study; 19 received CB and 18 BM transplantation. Results were compared with those obtained in 14 adults given BM transplantation for either malignant or nonmalignant disorders. MSCs were grown from BM aspirates obtained 1-17 and 2-192 months after allo-HSCT in pediatric and adult patients, respectively. MSC samples at the third-fourth passage were phenotypically characterized. Donor/recipient origin of MSCs was assessed by amelogenin assay and microsatellite analysis. Results: MSCs could be grown from 30 of 37 children; at the third-fourth passage MSCs resulted positive ( 6598%) for CD73, CD105, CD106, CD29, CD13, CD44 and negative ( 641%) for CD34, CD45, CD14. Mixed chimerism with donor cells was observed in 4 BM and 5 CB transplantation recipients, respectively; full recipient chimerism was detected in the remaining children. Full recipient MSC chimerism was observed also in all assessable (12/14) adult patients. Conclusions: BM of pediatric patients might be a more favorable milieu than that of adults for sustained engraftment of transplanted MSCs. MSCs able to engraft in the host can be transferred with cryopreserved CB units. \ua9 200

Influence of human cytomegalovirus reactivation on NK-cell reconstitution in patients given haploidentical T-cell depleted HSCT and umbilical cord blood transplantation

Influence of human cytomegalovirus reactivation on NK-cell reconstitution in patients given haploidentical T-cell depleted HSCT and umbilical cord blood transplantatio

Third-party bone marrow-derived mesenchymal stromal cell infusion before liver transplantation: A randomized controlled trial

Mesenchymal stromal cells (MSC) have emerged as a promising therapy to minimize the immunosuppressive regimen or induce tolerance in solid organ transplantation. In this randomized open-label phase Ib/IIa clinical trial, 20 liver transplant patients were randomly allocated (1:1) to receive a single pre-transplant intravenous infusion of third-party bone marrow-derived MSC or standard of care alone. The primary end-point was the safety profile of MSC administration during the one-year follow-up. Nineteen patients completed the study, and none of those who received MSC experienced infusion-related complications. The incidence of serious and non-serious adverse events was similar in the two groups. Circulating Treg/memory Treg and tolerant NK subset of CD56bright NK cells increased slightly over baseline, albeit not to a statistically significant extent, in MSC-treated patients but not in the control group. Graft function and survival, as well as histologic parameters and intragraft expression of tolerance-associated transcripts in 1-year protocol biopsies were similar in the two groups. In conclusion, pre-transplant MSC infusion in liver transplant recipients was safe and induced mild positive changes in immunoregulatory T and NK cells in the peripheral blood. This study opens the way for a trial on possible tolerogenic efficacy of MSC in liver transplantation. ClinicalTrials.gov identifier: NCT02260375