| 1. |
- Picerno, A, et al.
(author)
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The Icarus Flight of Perinatal Stem and Renal Progenitor Cells Within Immune System
- 2022
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In: Frontiers in immunology. - : Frontiers Media SA. - 1664-3224. ; 13, s. 840146-
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Journal article (peer-reviewed)abstract
- Our immune system actively fights bacteria and viruses, and it must strike a delicate balance between over- and under-reaction, just like Daedalus and Icarus in Greek mythology, who could not escape their imprisonment by flying too high or too low. Both human amniotic epithelial and mesenchymal stromal cells and the conditioned medium generated from their culture exert multiple immunosuppressive activities. They have strong immunomodulatory properties that are influenced by the types and intensity of inflammatory stimuli present in the microenvironment. Notably, very recently, the immunomodulatory activity of human adult renal stem/progenitor cells (ARPCs) has been discovered. ARPCs cause a decrease in Tregs and CD3+ CD4− CD8− (DN) T cells in the early stages of inflammation, encouraging inflammation, and an increase in the late stages of inflammation, favoring inflammation quenching. If the inflammatory trigger continues, however, ARPCs cause a further increase in DN T cells to avoid the development of a harmful inflammatory state. As in the flight of Daedalus and Icarus, who could not fly too high or too low to not destroy their wings by the heat of the sun or the humidity of the sea, in response to an inflammatory environment, stem cells seem to behave by paying attention to regulating T cells in the balance between immune tolerance and autoimmunity. Recognizing the existence of both suppressive and stimulatory properties, and the mechanisms that underpin the duality of immune reaction, will aid in the development of active immunotherapeutic approaches that manipulate the immune system to achieve therapeutic benefit.
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| 2. |
- Sallustio, F, et al.
(author)
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Role of Toll-Like Receptors in Actuating Stem/Progenitor Cell Repair Mechanisms: Different Functions in Different Cells
- 2019
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In: Stem cells international. - : Hindawi Limited. - 1687-966X .- 1687-9678. ; 2019, s. 6795845-
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Journal article (peer-reviewed)abstract
- Toll-like receptors (TLRs) represent one of the bridges that regulate the cross-talk between the innate and adaptive immune systems. TLRs interact with molecules shared and preserved by the pathogens of origin but also with endogenous molecules (damage/danger-associated molecular patterns (DAMPs)) that derive from injured tissues. This is probably why TLRs have been found to be expressed on several kinds of stem/progenitor cells (SCs). In these cells, the role of TLRs in the regulation of the basal motility, proliferation, differentiation processes, self-renewal, and immunomodulation has been demonstrated. In this review, we analyze the many different functions that the TLRs assume in SCs, pointing out that they can have different effects, depending on the background and on the kind of ligands that they recognize. Moreover, we discuss the TLR involvement in the response of SC to specific tissue damage and in the reparative processes, as well as how the identification of molecules mediating the differential function of TLR signaling could be decisive for the development of new therapeutic strategies. Considering the available studies on TLRs in SCs, here we address the importance of TLRs in sensing an injury by stem/progenitor cells and in determining their behavior and reparative activity, which is dependent on the conditions. Therefore, it could be conceivable that SCs employed in therapy could be potentially exposed to TLR ligands, which might modulate their therapeutic potential in vivo. In this context, to modulate SC proliferation, survival, migration, and differentiation in the pathological environment, we need to better understand the mechanisms of action of TLRs on SCs and learn how to control these receptors and their downstream pathways in a precise way. In this manner, in the future, cell therapy could be improved and made safer.
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| 3. |
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| 4. |
- D'Ascenzi, F., et al.
(author)
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Left atrial remodeling in patients undergoing transcatheter aortic valve implantation : a speckle tracking prospective study
- 2013
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In: European Heart Journal. - : Oxford University Press. - 0195-668X .- 1522-9645. ; 34:Supplement: 1, s. 338-338
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Journal article (other academic/artistic)abstract
- Background: Aortic Stenosis (AS) results in several Left Ventricular (LV) disturbances as well as progressive Left Atrial (LA) enlargement and dysfunction. Transcatheter Aortic Valve Implantation (TAVI) reverses LV remodelling and improves overall systolic function but its effect on LA function remains undetermined. The aim of this prospective study was toinvestigate the effects of TAVI on LA structure and function.Material and methods: We studied thirty-two patients with severe symptomatic AS and high surgical risk who underwent TAVI, using standard and 2-dimensional speckle-tracking echocardiography before, at 40-day and at 3-month follow-up.Results: Following TAVI, mean transvalvular gradient reduced (p<0.001). Both LA mean area index and LA mean volume index decreased at 40-day (16.2±6.4 vs. 12.5±2.9 cm2/m2, and 47.3±12.0 vs. 42.8±12.5 mL/m2, respectively, p<0.05) and values remained unchanged at 3 months. The reduction of LA size was accompanied by a significant increase in global PALS (14.4±3.9% vs. 19.1±4.7%, p<0.001) and global PACS (8.4±2.5% vs. 11.0±4.1%, p<0.05) at 3-month. After the procedure, LA stiffness measurements decreased and became significant at 3-month follow up (p<0.001). Pre-procedural trans-aortic mean gradient and pre-procedural LA volume were identified as predictors of global PALSincrease (p<0.0001) while the delta drop in trans-aortic mean gradient as predictors of LA volume index reduction 3 months after TAVI (p<0.0001).Conclusion: TAVI is associated with significant recovery of LA structure and function suggesting a reverse cavity remodelling. Such functional recovery is determined by the severity of pre-procedural valve stenosis.
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