Therapy free of cells vs human mesenchymal stem cells from umbilical cord stroma to treat the inflammation in OA.

Osteoarthritis (OA) is closely linked to the increase in the number of senescent cells in joint tissues, and the senescence-associated secretory phenotype (SASP) is implicated in cartilage degradation. In the last decade, extracellular vesicles (EV) in combination with the use of miRNAs to modify post-transcriptional expressions of multiple genes have shown their utility in new therapies to treat inflammatory diseases. This work delves into the anti-inflammatory effect of extracellular vesicles derived from mesenchymal stem cells (MSC) previously modified to inhibit the expression of miR-21. We compare the efficacy of two treatments, MSC with their miR-21 inhibited through lentiviral transfection and their EV, against inflammation in a new OA animal model. The modified MSC and their EV were intraperitoneally injected in an OA animal model twice. One month after treatment, we checked which therapy was the most effective to reduce inflammation compared with animals untreated. Treated OA model sera were analyzed for cytokines and chemokines. Subsequently, different organs were analyzed to validate the results obtained. EV were the most effective treatment to reduce chemokines and cytokines in serum of OA animals as well as SASP, in their organs checked by proteomic and genomic techniques, compared with MSC alone in a statistically significant way. In conclusion, MSC-miR-21--derived EV showed a higher therapeutic potential in comparison with MSCs-miR-21-. They ameliorate the systemic inflammation through inactivation of ERK1/2 pathway in OA in vivo model. Workflow of the realization of the animal model of OA by injecting cells into the joint cavity of the left knee of the animals, which produces an increase in serum cytokines and chemokines in the animals in addition to the increase in SASP and markers of inflammation. Inhibition of miR-21 in MSCs, from the stroma of the human umbilical cord, by lentivirus and extraction of their EVs by ultracentrifugation. Finally, application of MSC therapy with its miR-21 inhibited or its EVs produces a decrease in serum cytokines and chemokines in the treated animals, in addition to an increase in SASP and markers of inflammation. The cell-free therapy being the one that produces a greater decrease in the parameters studied.

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

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.