NF-κB/IKK Activation by Small Extracellular Vesicles Within the SASP

[Abstract] Cellular senescence plays an important role in different biological and pathological conditions. Senescent cells communicate with their microenvironment through a plethora of soluble factors, metalloproteases and extracellular vesicles (EV). Although much is known about the role that soluble factors play in senescence, the downstream signalling pathways activated by EV in senescence is unknown. To address this, we performed a small molecule inhibitor screen and have identified the IκB kinases IKKε, IKKα and IKKβ as essential for senescence mediated by EV (evSASP). By using pharmacological inhibitors of IKKε, IKKα and IKKβ, in addition to CRISPR/Cas9 targeting their respective genes, we find these pathways are important in mediating senescence. In addition, we find that senescence activation is dependent on canonical NF-κB transcription factors where siRNA targeting p65 prevent senescence. Importantly, these IKK pathways are also relevant to ageing as knockout of IKKA, IKKB and IKKE avoid the activation of senescence. Altogether, these findings open a new potential line of investigation in the field of senescence by targeting the negative effects of the evSASP independent of particular EV contents.AO’s lab is supported by BBSRC (BB/P000223/1) and Bart’s Charity Grant (MGU0497). J.A.F.-L is funded by the Xunta de Galicia Fellowship (ED481B 2017/117)Xunta de Galicia; ED481B 2017/117Reino Unido. Biotechnology and Biological Sciences Research Council; BB/P000223/1Barts Charity (Londres); MGU049

Classical and nonclassical intercellular communication in senescence and ageing

[Abstract] Intercellular communication refers to the different ways through which cells communicate with each other and transfer a variety of messages. These communication methods involve a number of different processes that occur individually or simultaneously, which change depending on the physiological or pathological context. The best characterized means of intercellular communication is the release of soluble factors that affect the function of neighboring cells. However, there are many other ways by which cells can communicate with each other. Here, we review the different means of intercellular communication including soluble factors in the context of senescence, ageing, and age-related diseases.Biotechnologyand Biological Sciences Research Council (UK); BB/P000223/1Barts Charity Grant; MGU049

Influence of aging on proliferation, pluripotency, immunogenic profiles from bone marrow mesenchymal stem cells

Programa Oficial de Doutoramento en Ciencias da Saúde. 5007V01[Resumen] Las células madre mesenquimales (CMMs) tiene una gran relevancia en la regeneración de tejidos mesenquimales como hueso y cartílago. El prometedor papel de las CMMs en terapia celular e ingeniería tisular parece estar limitado debido a la pérdida de potencial de regeneración con el incremento de la edad del donante. En esta investigación hemos tratado de entender como el envejecimiento influye en la capacidad de proliferación y pluripotencia en estas células y también en su potencial inmunogénico. CMMs de médula ósea procedentes de ratas Wistar de seis estadios de edad (neonato, infantil, juvenil, pre-pubertal, pubertal e adulto) fueron usadas en este estudio. Se llevo a cabo un ensayo proteómico cuantitativo usando iTRAQ 8-plex y las proteínas estadísticamente moduladas fueron agrupadas en tres procesos: pluripotencia, proliferación y metabolismo energético. Se midieron mediante citometría de flujo los marcadores de proliferación CD117 y Ki67. El análisis de los marcadores de pluripotencia Rex1, Oct4, Sox2 y Nanog usando reacción en cadena de la polimerasa a tiempo real. Evaluación biológica mediante diferenciaciones dirigidas usando medios específicos de osteogénesis, adipogénesis y condrogenénesis durante 14 días, las células diferenciadas fueron analizadas usando técnicas histoquímicas. También se realizaron ensayos enzimáticos de varias enzimas como L-lactato deshidrogenasa y glucosa-6-fosfato isomerasa para validar los datos obtenidos del iTRAQ. Para profundizar en el estudio de las diferencias obtenidas a nivel proteómico hemos analizado el transcriptoma de los seis grupos de edad de CMMs de médula ósea usando Next Generation Sequencing. Un total de 9628 genes se encontraron modulados significativamente entre los grupos de edad y estos fueron agrupados en rutas metabólicas. Encontramos en los grupos juvenil, pre-pubertal y adulto una gran cantidad de genes diferencialmente expresados relacionados con inflamación mediada por la ruta de señalización de quimiocinas y citoquinas comparados con el grupo control. Además, las vesículas extracelulares de estos grupos de edad fueron aisladas y caracterizadas usando el análisis de tráfico de nanopartículas y citometría de flujo y la expresión de varios micro-ARNs relacionados con la ruta de interés, se evaluaron por qPCR-RT. El miR-21-5p fue estadísticamente significativamente alto en vesículas extracelular de CMMs del grupo pre-pubertal, mediante experimentos funcionales inhibiendo su expresión , investigamos la modulación del receptor tipo Toll 4 y los patrones moleculares asociados al daño. El envejecimiento afecta al perfil de proliferación, pluripotencia e inmunogénico de CMMs de médula ósea, También afecta la producción, contenido de micro-ARNs pro-inflamatorios y la efectividad de las vesículas extracelulares procedentes de células madre mesenquimales de médula ósea. Estos descubrimientos son importantes para entender la influencia del envejecimiento en las células madre mesenquimales y el avance en el desarrollo de terapias basadas en vesículas extracelulares de las mismas.[Resumo] As células nai mesenquimais (CNMs) teñen unha gran relevancia na rexeneración de tecidos mesenquimais coma óso e cartilaxe. O prometedor papel das CNMs en terapia celular e inxenería tisular parece estar limitado debido a perda do potencial de rexeneración co incremento da idade do doante. Nesta investigación tratamos de entender coma o envellecemento inflúe na capacidade de proliferación e pluripotencia e no potencial inmunoxénica destas células. CNMs de medula ósea procedentes de ratas Wistar de seis estadios de idade (neonato, infantil, xuvenil, pre-púbere, púbere e adulto) foron empregadas neste estudo. Levouse a cabo un ensaio proteómico cuantitativo empregando iTRAQ 8-plex e as proteínas estadísticamente moduladas agrupáronse en tres procesos: pluripotencia, proliferación e metabolismo enerxético. Medironse empregando citometría de fluxo os marcadores de proliferación CD117 e Ki67. A analise dos marcadores de pluripotencia Rex1, Oct4, Sox2 e Nanog empregando a reacción en cadea da polimerasa a tempo real. A evaluación biolóxica mediante diferenciacións dirixidas empregando medios específicos de osteoxénesis, adipoxénesis e condroxénesis durante 14 días, as células diferenciadas foron evaluadas empregando técnicas histoquímicas. Tamén leváronse a cabo ensaios enzimáticos de varias enzimas coma L-lactato deshidroxenasa e glicosa-6-fosfato isomerasa para validar os datos obtidos do iTRAQ. Para profundizar no estudo das diferencias obtidas a nivel proteómico analizouse o transcriptoma dos seis grupos de idade das CNMs empregando Next Generation Sequencing. Un total de 9628 xenes atoparonse modulados significativamente entre os grupos de idades e estos foron agrupados en rutas metabólicas. Atopamos nos grupos xuvenil, pre-púbere e adulto una gran cantidade de xenes diferencialmente expresados relacionados coa inflamación mediada pola ruta de sinalización de quimiocinas e citoquinas comparadas co grupo control. Ademais, as vesículas extracelulares dos grupos de idade foron aisladas e caracterizadas empregando a análise de tráfico de nanopartículas e citometría de fluxo e a avaliación da expresión de varios micro-ARNs relacionados coa ruta de interese mediante qPCR-RT. O miR-21-5p foi estadísticamente significativamente alto nas vesículas extracelulares de CNMs do grupo pre-púbere, mediante experimentos funcionais, inhibindo a súa expresión, investigamos a modulación do receptor tipo Toll 4 e os patrones moleculares asociados ao dano. O envellecemento afecta ao perfil de proliferación, pluripotencia e inmunoxénico das CNMs de medula ósea. Tamén afecta a producción, contido de micro-ARNs pro-inflamatorios e a efectividade das vesículas extracelulares procedentes de CNMs de medula ósea. Estos descubrimentos son importantes para entender a influencia do envellecemento nas CNMs e o avance no desenvolvemento de terapias baseadas nas vesículas extracelularas das mesmas.[Abstract] Mesenchymal stem cells (MSCs) are highly relevant for regeneration of mesoderm tissues such as bone and cartilage. The promising role of MSCs in cell-based therapies and tissue engineering appears to be limited due to a decline of their regenerative potential with increasing donor age. In this research we have studied and treated to understand how aging influences in proliferation and pluripotency capacities from these cells and also into their immunogenic potential. Six age groups from bone marrow mesenchymal stem cells of Wistar rats were studied (newborn, infant, young, pre-pubertal, pubertal and adult). Quantitative proteomic assay was performance by iTRAQ-8-plex and the proteins statistically significant modulated were grouped in pluripotency, proliferative and metabolism processes. Proliferation makers, CD117 and Ki67 were measure by flow cytometry assay. Real time polymerase chain reaction analysis of pluripotency markers Rex1, Oct4, Sox2 and Nanog were done. Biological differentiation was realized using specific mediums for 14 days to induce osteogenesis, adipogenesis and chondrogenesis and differentiated cells were analysed using histochemical techniques. Enzymatic analysis of several enzymes as L-lactate dehydrogenase and glucose-6-phosphate isomerase were done to validate iTRAQ data. To deeply study these differences we have analyzed by Next Generation Sequencing six age groups from bone marrow mesenchymal stem cells. A total of 9628 genes presented differences of expression among age groups and those genes were grouped into metabolic pathways. We focused our research in young, pre-pubertal and adult groups which presented the highest amount of genes differentially expressed related with inflammation mediated by chemokine and cytokine signalling pathway when compared with newborn group which was used as a control. Afterwards, extracellular vesicles from those groups were isolated and characterized by nanoparticle tracking analysis and flow cytometry and several micro-RNAs were checked by qRT-PCR because of their relationship with the pathway of interest. Since miR-21-5p was statistically significant highest in extracellular vesicles from mesenchymal stem cells of pre-pubertal group, we realized a functional experiment inhibiting it expression and investigating the modulation of Toll-Like Receptor 4 and their link to damage-associated molecular patterns. Aging affects proliferation, pluripotency and immunogenic profiles of bone marrow mesenchymal stem cells. Also its affects production, content of pro-inflammatory miRs and affectivity of bone marrow mesenchymal stem cell-derived extracellular vesicles. These findings are important to the understanding about influence of the aging on mesenchymal stem cells and to advance in the development EV-based therapies

Effect of Aging on Behaviour of Mesenchymal Stem Cells

[Abstract] Organs whose source is the mesoderm lineage contain a subpopulation of stem cells that are able to differentiate among mesodermal derivatives (chondrocytes, osteocytes, adipocytes). This subpopulation of adult stem cells, called “mesenchymal stem cells” or “mesenchymal stromal cells (MSCs)”, contributes directly to the homeostatic maintenance of their organs; hence, their senescence could be very deleterious for human bodily functions. MSCs are easily isolated and amenable their expansion in vitro because of the research demanding to test them in many diverse clinical indications. All of these works are shown by the rapidly expanding literature that includes many in vivo animal models. We do not have an in-depth understanding of mechanisms that induce cellular senescence, and to further clarify the consequences of the senescence process in MSCs, some hints may be derived from the study of cellular behaviour in vivo and in vitro, autophagy, mitochondrial stress and exosomal activity. In this particular work, we decided to review these biological features in the literature on MSC senescence over the last three years.Xunta de Galicia; ED481B 2017/11

Small Extracellular Vesicles Have GST Activity and Ameliorate Senescence-Related Tissue Damage

[Abstract] Aging is a process of cellular and tissue dysfunction characterized by different hallmarks, including cellular senescence. However, there is proof that certain features of aging and senescence can be ameliorated. Here, we provide evidence that small extracellular vesicles (sEVs) isolated from primary fibroblasts of young human donors ameliorate certain biomarkers of senescence in cells derived from old and Hutchinson-Gilford progeria syndrome donors. Importantly, sEVs from young cells ameliorate senescence in a variety of tissues in old mice. Mechanistically, we identified sEVs to have intrinsic glutathione-S-transferase activity partially due to the high levels of expression of the glutathione-related protein (GSTM2). Transfection of recombinant GSTM2 into sEVs derived from old fibroblasts restores their antioxidant capacity. sEVs increase the levels of reduced glutathione and decrease oxidative stress and lipid peroxidation both in vivo and in vitro. Altogether, our data provide an indication of the potential of sEVs as regenerative therapy in aging

High-Throughput Screen Detects Calcium Signaling Dysfunction in Hutchinson-Gilford Progeria Syndrome

[Abstract] Hutchinson–Gilford progeria syndrome (HGPS) is a deadly childhood disorder, which is considered a very rare disease. It is caused by an autosomal dominant mutation on the LMNA gene, and it is characterized by accelerated aging. Human cell lines from HGPS patients and healthy parental controls were studied in parallel using next-generation sequencing (NGS) to unravel new non-previously altered molecular pathways. Nine hundred and eleven transcripts were differentially expressed when comparing healthy versus HGPS cell lines from a total of 21,872 transcripts; ITPR1, ITPR3, CACNA2D1, and CAMK2N1 stood out among them due to their links with calcium signaling, and these were validated by Western blot analysis. It was observed that the basal concentration of intracellular Ca2+ was statistically higher in HGPS cell lines compared to healthy ones. The relationship between genes involved in Ca2+ signaling and mitochondria-associated membranes (MAM) was demonstrated through cytosolic calcium handling by means of an automated fluorescent plate reading system (FlexStation 3, Molecular Devices), and apoptosis and mitochondrial ROS production were examined by means of flow cytometry analysis. Altogether, our data suggest that the Ca2+ signaling pathway is altered in HGPS at least in part due to the overproduction of reactive oxygen species (ROS). Our results unravel a new therapeutic window for the treatment of this rare disease and open new strategies to study pathologies involving both accelerated and healthy aging.Xunta de Galicia; ED481D-2021-020This work was funded by the Spanish National Health Institute Carlos III (PI20/00497) awarded to M.C.A. Furthermore, J.A.F.-L. is funded by the Xunta de Galicia Fellowship (ED481D-2021-020

Proteomic Applications in the Study of Human Mesenchymal Stem Cells

Mesenchymal stem cells (MSCs) are undifferentiated cells with an unlimited capacity for self-renewal and able to differentiate towards specific lineages under appropriate conditions. MSCs are, a priori, a good target for cell therapy and clinical trials as an alternative to embryonic stem cells, avoiding ethical problems and the chance for malignant transformation in the host. However, regarding MSCs, several biological implications must be solved before their application in cell therapy, such as safe ex vivo expansion and manipulation to obtain an extensive cell quantity amplification number for use in the host without risk accumulation of genetic and epigenetic abnormalities. Cell surface markers for direct characterization of MSCs remain unknown, and the precise molecular mechanisms whereby growth factors stimulate their differentiation are still missing. In the last decade, quantitative proteomics has emerged as a promising set of techniques to address these questions, the answers to which will determine whether MSCs retain their potential for use in cell therapy. Proteomics provides tools to globally analyze cellular activity at the protein level. This proteomic profiling allows the elucidation of connections between broad cellular pathways and molecules that were previously impossible to determine using only traditional biochemical analysis. However; thus far, the results obtained must be orthogonally validated with other approaches. This review will focus on how these techniques have been applied in the evaluation of MSCs for their future applications in safe therapies.Instituto de Salud Carlos III; PI11/0279

Therapeutic Potential for Regulation of the Nuclear Factor Kappa-B Transcription Factor p65 to Prevent Cellular Senescence and Activation of Pro-Inflammatory in Mesenchymal Stem Cells

[Abstract] Mesenchymal stem cells have an important potential in the treatment of age-related diseases. In the last years, small extracellular vesicles derived from these stem cells have been proposed as cell-free therapies. Cellular senescence and proinflammatory activation are involved in the loss of therapeutic capacity and in the phenomenon called inflamm-aging. The regulators of these two biological processes in mesenchymal stem cells are not well-known. In this study, we found that p65 is activated during cellular senescence and inflammatory activation in human umbilical cord-derived mesenchymal stem cell. To demonstrate the central role of p65 in these two processes, we used smallmolecular inhibitors of p65, such as JSH-23, MG-132 and curcumin. We found that the inhibition of p65 prevents the cellular senescence phenotype in human umbilical cord-derived mesenchymal stem cells. Besides, p65 inhibition produced the inactivation of proinflammatory molecules as components of a senescence-associated secretory phenotype (SASP) (interleukin-6 and interleukin-8 (IL-6 and IL-8)). Additionally, we found that the inhibition of p65 prevents the transmission of paracrine senescence between mesenchymal stem cells and the proinflammatory message through small extracellular vesicles. Our work highlights the important role of p65 and its inhibition to restore the loss of functionality of small extracellular vesicles from senescent mesenchymal stem cells and their inflamm-aging signature.Instituto de Salud Carlos III; PI20/00497Xunta de Galicia; ED481B 2017/11

Extracellular Vesicles as Potential Tools for Regenerative Therapy

[Abstract] Small extracellular vesicles released by fibroblasts from young human donors diminish lipid peroxidation in senescent cells and in different old mice organs due to their enrichment in Glutathione-S-transferase Mu lipid antioxidant activity.The London School of Medicine and Dentistry; MGU0497Biotechnology and Biological Sciences Research Council; BB/P000223/1Instituto de Salud Carlos III; CP19-0010Ministerio de Economía, Industria y Competitividad; SAF2016-78666RXunta de Galicia; ED481B 2017/11

Influence of Mesenchymal Stem Cell-Derived Extracellular Vesicles in Vitro and their Role in Ageing

[Abstract] Introduction: This study assessed whether mesenchymal stem cell (MSC)-derived extracellular vesicles influenced ageing and pluripotency markers in cell cultures where they are added. Methods: MSC-derived extracellular vesicles from old and young rat bone marrows were isolated by ultracentrifugation and were characterised by western blotting, nanoparticle tracking analysis (NTA) and transmission electron microscopy (TEM). They were added to young and old MSC cultures. Real-time quantitative reverse transcription polymerase chain reactions and western blot analysis were performed to check the markers of ageing (vinculin and lamin A), pluripotency markers (Nanog and Oct4) and components of the mTOR signalling pathway (Rictor, Raptor, AKT and mTOR) in these cell populations. Subsequently, microRNA (miR)-188-3p expression was transiently inhibited in young MSCs to demonstrate the influence of mTOR2 on MSC ageing. Results: Incubation with young MSC-derived extracellular vesicles decreased the levels of ageing markers and components of the mTOR pathway and increased the pluripotency markers from old MSC populations. By contrast, incubation of young MSCs with old MSC-derived extracellular vesicles generated the reverse effects. Inhibition of miR-188-3p expression in young MSCs produced extracellular vesicles that when incubated with old MSCs produced an increase in the levels of Rictor, as well as a decrease of phosphor-AKT, as indicated by a significant decrease in beta-galactosidase staining. Conclusions: MSC-derived extracellular vesicles affected the behaviour of MSC cultures, based on their composition, which could be modified in vitro. These experiments represented the basis for the development of new therapies against ageing-associated diseases using MSC-derived extracellular vesicles.JAF-L is the recipient of a postdoctoral fellowship funded by Consellería de Cultura, Educación e Ordenación Universitaria, Xunta de Galicia (Spain