A major issue in aging research is how cellular phenomena affect aging at the systemic level. Emerging evidence suggests that DNA damage response (DDR) signaling is a key mechanism linking DNA damage accumulation, cell senescence, and organism aging. DDR activation in senescent cells promotes acquisition of a proinflammatory secretory phenotype (SASP), which in turn elicits DDR and SASP activation in neighboring cells, thereby creating a proinflammatory environment extending at the local and eventually the systemic level. DDR activation is triggered by genomic lesions as well as emerging bacterial and viral metagenomes. Therefore, the buildup of cells with an activated DDR probably fuels inflamm-aging and predisposes to the development of the major age-related diseases (ARDs). Micro (mi)-RNAs - non-coding RNAs involved in gene expression modulation - are released locally and systemically by a variety of shuttles (exosomes, lipoproteins, proteins) that likely affect the efficiency of their biological effects. Here we suggest that some miRNAs, previously found to be associated with inflammation and senescence - miR-146, miR-155, and miR-21 - play a central role in the interplay among DDR, cell senescence and inflamm-aging. The identification of the functions of shuttled senescence-associated miRNAs is expected to shed light on the aging process and on how to delay ARD development.

Human dental pulp is considered an interesting source of adult stem cells, due to the low-invasive isolation procedures, high content of stem cells and its peculiar embryological origin from neural crest. Based on our previous findings, a dental pulp stem cells sub-population, enriched for the expression of STRO-1, c-Kit, and CD34, showed a higher neural commitment. However, their biological properties were compromised when cells were cultured in adherent standard conditions. The aim of this study was to evaluate the ability of three dimensional floating spheres to preserve embryological and biological properties of this sub-population. In addition, the expression of the inwardly rectifying potassium channel Kir4.1, Fas and FasL was investigated in 3D-sphere derived hDPSCs. Our data showed that 3D sphere-derived hDPSCs maintained their fibroblast-like morphology, preserved stemness markers expression and proliferative capability. The expression of neural crest markers and Kir4.1 was observed in undifferentiated hDPSCs, furthermore this culture system also preserved hDPSCs differentiation potential. The expression of Fas and FasL was observed in undifferentiated hDPSCs derived from sphere culture and, noteworthy, FasL was maintained even after the neurogenic commitment was reached, with a significantly higher expression compared to osteogenic and myogenic commitments. These data demonstrate that 3D sphere culture provides a favorable micro-environment for neural crest-derived hDPSCs to preserve their biological properties.

The microenvironment in psoriasis differs from those of atopic dermatitis and healthy skin; it could induce resident MSCs to produce angiogenic and proinflammatory mediators which lead to a reduction in the antioxidant capacity of these cells, contributing to the development of skin lesions in psoriasis.

The growing occurrence of bone disorders and the increase in aging population have resulted in the need for more effective therapies to meet this request. Bone tissue engineering strategies, by combining biomaterials, cells, and signaling factors, are seen as alternatives to conventional bone grafts for repairing or rebuilding bone defects. Indeed, skeletal tissue engineering has not yet achieved full translation into clinical practice because of several challenges. Bone biofabrication by additive manufacturing techniques may represent a possible solution, with its intrinsic capability for accuracy, reproducibility, and customization of scaffolds as well as cell and signaling molecule delivery. This review examines the existing research in bone biofabrication and the appropriate cells and factors selection for successful bone regeneration as well as limitations affecting these approaches. Challenges that need to be tackled with the highest priority are the obtainment of appropriate vascularized scaffolds with an accurate spatiotemporal biochemical and mechanical stimuli release, in order to improve osseointegration as well as osteogenesis.

The expression of genes encoding for Th1, Th2 and Th17 cytokines has been extensively evaluated in differentiated skin cells of psoriatic patients. The microenvironment exerts a control on the phenotype of resident mesenchymal stem cells (MSCs) into the skin of psoriasis patients. Aim of the study was to extensively evaluate the relative expression of 43 genes encoding for Th1, Th2 and Th17 cytokines in MSCs isolated from skin of psoriasis patients. MSCs resident into psoriatic skin were isolated, characterized and profiled by PCR array for the relative expression of genes encoding for cytokines involved in Th1, Th2 and Th17 pathways. MSCs isolated from the skin of healthy subjects were used as control. The MSCs isolated from skin of psoriasis patients showed a greater relative expression of the most part of the analyzed genes encoding for Th1 and Th17 cytokines: INF-γ, CCR5, CXCL9, CXCL10, IL6, IL8, TNF-α, IL23A, CCL2, CCL20, CXCL2, CXCL5, IL17C, IL17F, IL17RA, IL21, TLR2 than healthy subjects. On the contrary, the relative expression of genes encoding for Th2 cytokines: CCL1, CCL22, CXCL12, IL2, IL3, IL4, IL13B, IL 22, IL 27, TGF-β1, was similar between the MSCs isolated from psoriasis and healthy subjects. In conclusion, the MSCs isolated from psoriasis show an imbalance between the Th1-Th17 and Th2 pathways, which reflects the well-known abnormal balance observed in differentiated skin cells. This evidence could strengthen the hypothesis of an early involvement of resident MSCs in the pathogenesis of psoriasis.