Platelet lysate activity in the wound-healing process: activation of endothelial and adipose tissue progenitor and differentiated cells

Platelet lysate activity in the wound-healing process: activation of endothelial and adipose tissue progenitor and differentiated cell

Platelet Lysate Inhibits NF-κB Activation and Induces Proliferation and an Alert State in Quiescent Human Umbilical Vein Endothelial Cells Retaining Their Differentiation Capability.

open6Injured blood vessel repair and blood circulation re-establishment are crucial events for tissue repair. We investigated in primary cultures of human umbilical vein endothelial cells (HUVEC), the eects of platelet lysate (PL), a cocktail of factors released by activated platelets following blood vessel disruption and involved in the wound-healing process triggering. PL exerted a protective eect on HUVEC in an inflammatory milieu by inhibiting IL-1-activated NF-B pathway and by inducing the secretion of PGE2, a pro-resolving molecule in the wound microenvironment. Moreover, PL enhanced HUVEC proliferation, without aecting their capability of forming tube-like structures on matrigel, and activated resting quiescent cells to re-enter cell cycle. In agreement with these findings, proliferation-related pathways Akt and ERK1/2 were activated. The expression of the cell-cycle activator Cyclin D1 was also enhanced, as well as the expression of the High Mobility Group Box-1 (HMGB1), a protein of the alarmin group involved in tissue homeostasis, repair, and remodeling. These in vitro data suggest a possible in vivo contribution of PL to new vessel formation after a wound by activation of cells resident in vessel walls. Our biochemical study provides a rationale for the clinical use of PL in the treatment of wound healing-related pathologies.openRomaldini A, Ulivi V, Nardini M, Mastrogiacomo M,Cancedda R, Descalzi FRomaldini, A; Ulivi, V; Nardini, M; Mastrogiacomo, M; Cancedda, R; Descalzi,

Platelet Lysate Activates Human Subcutaneous Adipose Tissue Cells by Promoting Cell Proliferation and Their Paracrine Activity Toward Epidermal Keratinocytes

Skin chronic wounds are non-healing ulcerative defects, which arise in association with a morbidity state, such as diabetes and vascular insufficiency or as the consequence of systemic factors including advanced age. Platelet Rich Plasma, a platelet-rich blood fraction, can significantly improve the healing of human skin chronic ulcers. Given that the subcutaneous adipose tissue is located beneath the skin and plays a role in the skin homeostasis, in this study, we investigated the in vitro response of human subcutaneous adipose tissue cells to platelet content in a model mimicking in vitro the in situ milieu of a deep skin injury. Considering that, at the wound site, plasma turn to serum, platelets are activated and inflammation occurs, human adipose-derived stromal cells (hASC) were cultured with Human Serum (HS) supplemented or not with Platelet Lysate (PL) and/or IL-1α. We observed that HS sustained hASC proliferation more efficiently than FBS and induced a spontaneous adipogenic differentiation in the cells. PL added to HS enhanced hASC proliferation, regardless the presence of IL-1α. In the presence of PL, hASC progressively lessened the adipogenic phenotype, possibly because the proliferation of less committed cells was induced. However, these cells resumed adipogenesis in permissive conditions. Accordingly, PL induced in quiescent cells activation of the proliferation-related pathways ERK, Akt, and STAT-3 and expression of Cyclin D1. Moreover, PL induced an early and transient increase of the pro-inflammatory response triggered by IL-1α, by inducing COX-2 expression and secretion of a large amount of PGE2, IL-6, and IL-8. Media conditioned by PL-stimulated hASC exerted a chemotactic activity on human keratinocytes and favored the healing of an in vitro scratch wound. In order to bridge the gap between in vitro results and possible in vivo events, the stimuli were also tested in ex vivo cultures of in toto human adipose tissue biopsies (hAT). PL induced cell proliferation in hAT and outgrowth of committed progenitor cells able to differentiate in permissive conditions. In conclusion, we report that the adipose tissue responds to the wound microenvironment by activating the proliferation of adipose tissue progenitor cells and promoting the release of factors favoring wound healing

Inside the Bone: Tissue Engineering and Regenerative Medicine Applications in Orthopedics

One of the main problems, not fully resolved in orthopedics yet, is the regeneration of large bone defects. The intricate bone composition makes the healing process very complex when dealing with extensive lesions. Although traditional therapeutic approaches allowed significant progresses by proposing new bone substitutes and prosthetic devices, the obtained results remain questionable. To regenerate the bone tissue, tissue engineering focused on the use of mesenchymal cells derived from the bone marrow, in the attempt to restore an environment more suitable for the restitutio ad integrum of the tissue. This chapter describes and discusses the tissue engineering approach in bone repair with particular regard to the new investigative tools developed in recent years to monitor the process

Amniotic Membrane-Derived Mesenchymal Cells and Their Conditioned Media: Potential Candidates for Uterine Regenerative Therapy in the Horse

<div><p>Amniotic membrane-derived mesenchymal cells (AMCs) are considered suitable candidates for a variety of cell-based applications. In view of cell therapy application in uterine pathologies, we studied AMCs in comparison to cells isolated from the endometrium of mares at diestrus (EDCs) being the endometrium during diestrus and early pregnancy similar from a hormonal standpoint. In particular, we demonstrated that amnion tissue fragments (AM) shares the same transcriptional profile with endometrial tissue fragments (ED), expressing genes involved in early pregnancy (<i>AbdB-like Hoxa</i> genes), pre-implantantion conceptus development (<i>Erα, PR</i>, <i>PGRMC1</i> and <i>mPR</i>) and their regulators (<i>Wnt7a</i>, <i>Wnt4a</i>). Soon after the isolation, only AMCs express <i>Wnt4a</i> and <i>Wnt7a</i>. Interestingly, the expression levels of prostaglandin-endoperoxide synthase 2 (<i>PTGS2</i>) were found greater in AM and AMCs than their endometrial counterparts thus confirming the role of AMCs as mediators of inflammation. The expression of nuclear progesterone receptor (PR), membrane-bound intracellular progesterone receptor component 1 (<i>PGRMC1</i>) and membrane-bound intracellular progesterone receptor (<i>mPR</i>), known to lead to improved endometrial receptivity, was maintained in AMCs over 5 passages <i>in vitro</i> when the media was supplemented with progesterone. To further explore the potential of AMCs in endometrial regeneration, their capacity to support resident cell proliferation was assessed by co-culturing them with EDCs in a transwell system or culturing in the presence of AMC-conditioned medium (AMC-CM). A significant increase in EDC proliferation rate exhibited the crucial role of soluble factors as mediators of stem cells action. The present investigation revealed that AMCs, as well as their derived conditioned media, have the potential to improve endometrial cell replenishment when low proliferation is associated to pregnancy failure. These findings make AMCs suitable candidates for the treatment of endometrosis in mares.</p></div

Oligonucleotide sequences used for RT-PCR analysis.

<p>Oligonucleotide sequences used for RT-PCR analysis.</p

Molecular characterization of endometrial tissue (ED) and amnion (AM) (A), and endometrial cells at diestrus stage (EDCs) and amniotic-derived stem cells (AMCs) (B).

<p>Qualitative and quantitative RT–PCR analysis for the expression of genes associated to differentiation of uterine stromal cells during early pregnancy (<i>Hoxa9</i>), those influencing pre-implantantion conceptus development (<i>ERα</i>, <i>ERβ</i>, <i>PR, PGRMC1</i> and <i>mPR</i>) and their regulators (<i>Wnt7a</i>, <i>Wnt4a</i>), and prostaglandin E₂ synthase (<i>PTGS2</i>), <i>FOXO1</i>, <i>SGK1</i>, and <i>TP53</i>. <i>GAPDH</i> was used as reference gene.</p

Cell morphology. Monolayer of AMCs (A) and EDCs (B); tridimensional cluster of AMCs (C).

<p>Magnification, x 20; scale bar  = 20 µm.</p