The potential of GMP-compliant platelet lysate to induce a permissive state for cardiovascular transdifferentiation in human mediastinal adipose tissue-derived mesenchymal stem cells

Remote Adipose Tissue-Derived Stromal Cells of Patients with Lung Adenocarcinoma Generate a Similar Malignant Microenvironment of the Lung Stromal Counterpart

Cancer alters both local and distant tissue by influencing the microenvironment. In this regard, the interplay with the stromal fraction is considered critical as this latter can either foster or hamper the progression of the disease. Accordingly, the modality by which tumors may alter distant niches of stromal cells is still unclear, especially at early stages. In this short report, we attempt to better understand the biology of this cross-talk. In our "autologous stromal experimental setting," we found that remote adipose tissue-derived mesenchymal stem cells (mediastinal AMSC) obtained from patients with lung adenocarcinoma sustain proliferation and clonogenic ability of A549 and human primary lung adenocarcinoma cells similarly to the autologous stromal lung counterpart (LMSC). This effect is not observed in lung benign diseases such as the hamartochondroma. This finding was validated by conditioning benign AMSC with supernatants from LAC for up to 21 days. The new reconditioned media of the stromal fraction so obtained, was able to increase cell proliferation of A549 cells at 14 and 21 days similar to that derived from AMSC of patients with lung adenocarcinoma. The secretome generated by remote AMSC revealed overlapping to the corresponding malignant microenvironment of the autologous local LMSC. Among the plethora of 80 soluble factors analyzed by arrays, a small pool of 5 upregulated molecules including IL1-β, IL-3, MCP-1, TNF-α, and EGF, was commonly shared by both malignant-like autologous A- and L-MSC derived microenvironments vs those benign. The bioinformatics analysis revealed that these proteins were strictly and functionally interconnected to lung fibrosis and proinflammation and that miR-126, 101, 486, and let-7-g were their main targets. Accordingly, we found that in lung cancer tissues and blood samples from the same set of patients here employed, miR-126 and miR-486 displayed the highest expression levels in tissue and blood, respectively. When the miR-126-3p was silenced in A549 treated with AMSC-derived conditioned media from patients with lung adenocarcinoma, cell proliferation decreased compared to control media.

Human platelet lysate-derived extracellular vesicles enhance angiogenesis through miR-126

OBJECTIVES

Extracellular vesicles (EVs) are key biological mediators of several physiological functions within the cell microenvironment. Platelets are the most abundant source of EVs in the blood. Similarly, platelet lysate (PL), the best platelet derivative and angiogenic performer for regenerative purposes, is enriched of EVs, but their role is still too poorly discovered to be suitably exploited. Here, we explored the contribution of the EVs in PL, by investigating the angiogenic features extrapolated from that possessed by PL.

METHODS

We tested angiogenic ability and molecular cargo in 3D bioprinted models and by RNA sequencing analysis of PL-derived EVs.

RESULTS

A subset of small vesicles is highly represented in PL. The EVs do not retain aggregation ability, preserving a low redox state in human umbilical vein endothelial cells (HUVECs) and increasing the angiogenic tubularly-like structures in 3D endothelial bioprinted constructs. EVs resembled the miRNome profile of PL, mainly enriched with small RNAs and a high amount of miR-126, the most abundant angiogenic miRNA in platelets. The transfer of miR-126 by EVs in HUVEC after the in vitro inhibition of the endogenous form, restored angiogenesis, without involving VEGF as a downstream target in this system.

CONCLUSION

PL is a biological source of available EVs with angiogenic effects involving a miRNAs-based cargo. These properties can be exploited for targeted molecular/biological manipulation of PL, by potentially developing a product exclusively manufactured of EVs.

A critical appraisal of humanized alternatives to fetal bovine serum for clinical applications of umbilical cord derived mesenchymal stromal cells

OBJECTIVE

The study is aimed to verify the possibility of using humanized alternatives to fetal bovine serum (FBS) such as umbilical cord blood plasma (CBP) and AB⁺ plasma to support the long-term growth of mesenchymal stromal cells (MSCs) derived from the umbilical cord. We hypothesized that umbilical CBP would be a potential substitute to FBS, especially for small scale autologous clinical transplantations.

METHODS

The MSCs were cultured for six consecutive passages to evaluate xeno-free media's ability to support long-term growth. Cell proliferation rates, colony-forming-unit (CFU) efficiency and population doublings of expanded MSCs, were investigated. Ex vivo expanded MSCs were further characterized using flow cytometry and quantitative PCR. The impact of cryopreservation and composition of cryomedium on phenotype, viability of MSC was also assessed.

RESULTS

Our results on cell proliferation, colony-forming unit efficiency suggested that the expansion of the cells was successfully carried out in media supplemented with humanized alternatives. MSCs showed lower CFU counts in FBS (~ 25) than humanized alternatives (~ 35). The gene expression analysis revealed that transcripts showed significant differential expression by two to three folds in the FBS group compared with MSCs grown in medium with humanized alternatives (p < 0.05). In addition, MSCs grown in a medium with FBS had more osteogenic activity, a signature of unwanted differentiation. The majority of ex vivo expanded MSCs at early and late passages expressed CD44⁺, CD73⁺, CD105⁺, CD90⁺, and CD166⁺ in all the experimental groups tested (~ 90%). In contrast to the other MSC surface markers, expression levels of STRO-1⁺ (~ 21-10%) and TNAP⁺ (~ 29-11%) decreased with the increase in passage number for MSCs cultured in a FBS-supplemented medium (p < 0.05).

CONCLUSION

Our results established that CBP supported culture of umbilical cord tissue-derived MSCs and is a safer Xeno free replacement to FBS. The use of CBP also enables the storage of umbilical cord tissue derived MSCs in patient-specific conditions to minimize adverse events if cells are delivered directly to the patient.

Substantial Overview on Mesenchymal Stem Cell Biological and Physical Properties as an Opportunity in Translational Medicine

Mesenchymal stem cells (MSC) have piqued worldwide interest for their extensive potential to treat a large array of clinical indications, their unique and controversial immunogenic and immune modulatory properties allowing ample discussions and debates for their possible applications. Emerging data demonstrating that the interaction of biomaterials and physical cues with MSC can guide their differentiation into specific cell lineages also provide new interesting insights for further MSC manipulation in different clinical applications. Moreover, recent discoveries of some regulatory molecules and signaling pathways in MSC niche that may regulate cell fate to distinct lineage herald breakthroughs in regenerative medicine. Although the advancement and success in the MSC field had led to an enormous increase in the amount of ongoing clinical trials, we still lack defined clinical therapeutic protocols. This review will explore the exciting opportunities offered by human and animal MSC, describing relevant biological properties of these cells in the light of the novel emerging evidence mentioned above while addressing the limitations and challenges MSC are still facing.

Oral Plaque from Type 2 Diabetic Patients Reduces the Clonogenic Capacity of Dental Pulp-Derived Mesenchymal Stem Cells

Type 2 diabetes (T2D) is a major metabolic disease and a key epigenetic risk factor for the development of additional clinical complications. Among them, periodontitis (PD), a severe inflammatory disease ascribable to a dysregulated physiology and composition of the oral microbiota, represents one of the most relevant complications. Periodontitis can impact the structure of the tooth and likely the stem and progenitor cell pool, which actively contributes to the periodontal microenvironment and homeostasis. Modifications of the oral plaque play a key role in the etiopathogenesis of PD caused by T2D. However, to what extent the biology of the progenitor pool is affected has still to be elucidated. In this short report, we aimed to explore the biological effects of oral plaque derived from T2D patients with PD in comparison to non-diabetic patients with PD. Oral plaque samples were isolated from T2D and non-diabetic subjects with PD. Dental pulp stem cells (DPSCs), derived from the premolar tooth, were conditioned for 21 days with oral plaque samples and tested for their clonogenic ability. Cultures were also induced to differentiate towards the osteogenic lineage, and ALP and osteocalcin gene expression levels were evaluated by real-time qPCR. Results have shown that the number of clones generated by DPSCs exposed to T2D oral plaque was significantly lower compared to controls (ctl). The multivariate analysis confirmed that the decreased clonogenesis was significantly correlated only with T2D diagnosis. Moreover, the effect of T2D oral plaque was specific to DPSCs. Indicators of osteogenic differentiation were not significantly affected. This study provides a new biological insight into the effects ascribable to T2D in PD.

Platelet Lysate-Derived Neuropeptide y Influences Migration and Angiogenesis of Human Adipose Tissue-Derived Stromal Cells

Neuropeptide Y (NPY), a powerful neurotransmitter of the central nervous system, is a key regulator of angiogenesis and biology of adipose depots. Intriguingly, its peripheral vascular and angiogenic powerful activity is strictly associated to platelets, which are source of clinical hemoderivates, such as platelet lysate (PL), routinely employed in several clinical applications as wound healing, and to preserve ex vivo the progenitor properties of the adipose stromal cells pool. So far, the presence of NPY in PL and its biological effects on the adipose stromal cell fraction (ASCs) have never been investigated. Here, we aimed to identify endogenous sources of NPY such as PL-based preparations and to investigate which biological properties PL-derived NPY is able to exert on ASCs. The results show that PL contains a high amount of NPY, which is in part also excreted by ASCs when stimulated with PL. The protein levels of the three main NPY subtype receptors (Y1, Y2, Y5) are unaltered by stimulation of ASCs with PL, but their inhibition through selective pharmacological antagonists, considerably enhances migration, and a parallel reduction of angiogenic features of ASCs including decrease in VEGF mRNA and intracellular calcium levels, both downstream targets of NPY. The expression of VEGF and NPY is enhanced within the sites of neovascularisation of difficult wounds in patients after treatment with leuco-platelet concentrates. Our data highlight the presence of NPY in PL preparations and its peripheral effects on adipose progenitors.

Signal transduction growth factors: the effective governance of transcription and cellular adhesion in cancer invasion

Giulio Bizzozero classified the tissues concerning their capacity to self-renew during the adult life in labile, stable and permanent tissues. In 1940 Viktor Hamburger and Rita Levi Montalcini exposed the possibility to induce the growth of permanent cells thanks to a specific ligand Nerve Growth Factor (NGF). Stanley Cohen purified a protein the Epidermal Growth Factor (EGF), able to induce epidermis proliferation and to elicit precocious eye disclosure and teeth eruption, establishing the “inverse” relationships between the proliferation and differentiation. These two biological effects induced by EGF were according to EGFR signaling is involved in a large array of cellular functions such as proliferation, survival, adhesion, migration and differentiation. This review is focused on the key role of growth factors signaling and their downstream effectors in physiological and in pathological phenomena, the authors highlight the governance of Growth factors during the EMT in cancer invasion.

Givinostat reduces adverse cardiac remodeling through regulating fibroblasts activation

Cardiovascular diseases (CVDs) are a major burden on the healthcare system: indeed, over two million new cases are diagnosed every year worldwide. Unfortunately, important drawbacks for the treatment of these patients derive from our current inability to stop the structural alterations that lead to heart failure, the common endpoint of many CVDs. In this scenario, a better understanding of the role of epigenetics – hereditable changes of chromatin that do not alter the DNA sequence itself – is warranted. To date, hyperacetylation of histones has been reported in hypertension and myocardial infarction, but the use of inhibitors for treating CVDs remains limited. Here, we studied the effect of the histone deacetylase inhibitor Givinostat on a mouse model of acute myocardial infarction. We found that it contributes to decrease endothelial-to-mesenchymal transition and inflammation, reducing cardiac fibrosis and improving heart performance and protecting the blood vessels from apoptosis through the modulatory effect of cardiac fibroblasts on endothelial cells. Therefore, Givinostat may have potential for the treatment of CVDs.

Stem Cells in Cardiovascular Medicine: the Road to Regenerative Therapies

PURPOSE OF REVIEW

The purpose of this review is to provide a broad overview of current trends in stem cell research and its applications in cardiovascular medicine. Researches on different stem cell sources, their inherent characteristics, and the limitations they have in medical applications are discussed. Additionally, uses of stem cells for both modeling and treating cardiovascular disease are discussed, taking note of the obstacles these engineered interventions must overcome to be clinically viable.

RECENT FINDINGS

Tissue engineering aims to replace dysfunctional tissues with engineered constructs. Stem cell technologies have been a great enabling factor in working toward this goal. Many tissue-engineered products are in development that utilize stem cell technology. Although promising, some refinement must be made to these constructs with respect to safety and functionality. A deeper understanding of basic differentiation and tissue developmental mechanisms is required to allow these engineered tissues to be translated into the clinic.

Human eyelid adipose tissue-derived Schwann cells promote regeneration of a transected sciatic nerve

Schwann cells (SCs) can promote the regeneration of injured peripheral nerves while the clinical application is limited by donor site complications and the inability to generate an ample amount of cells. In this study, we have isolated human eyelid adipose-derived Schwann cells (hE-SCs) from human eyelid adipose tissue and identified the cell phenotype and function. Using immunofluorescence and H & E staining, we detected subtle nerve fibers and SCs in human eyelid adipose tissue. Immunofluorescence staining indicated that hE-SCs expressed glial markers, such as S100, p75NTR GFAP, Sox10 and Krox20. To explore whether hE-SCs promote the regeneration of injured peripheral nerves in vivo, a Balb/c-nu mice model was used in the study, and mice were randomly assigned to five groups: Matrigel; hE-SCs/P0; hE-SCs/P2; hE-FLCs/P2; and Autograft. After 12 weeks, functional and histological assessments of the regenerated nerves showed that sciatic nerve defect was more effectively repaired in the hE-SCs/P2 group which achieved 66.1 ± 6.5% purity, than the other three groups and recovered to similar level to the Autograft group. These results indicated that hE-SCs can promote the regeneration of injured peripheral nerve and the abundant, easily accessible supply of adipose tissue might be a promising source of SCs for peripheral nerve repair.

Potency testing of mesenchymal stromal cell growth expanded in human platelet lysate from different human tissues

Background

Mesenchymal stromal cells (MSCs) have been largely investigated, in the past decade, as potential therapeutic strategies for various acute and chronic pathological conditions. MSCs isolated from different sources, such as bone marrow (BM), umbilical cord tissue (UCT) and adipose tissue (AT), share many biological features, although they may show some differences on cumulative yield, proliferative ability and differentiation potential. The standardization of MSCs growth and their functional amplification is a mandatory objective of cell therapies. The aim of this study was to evaluate the cumulative yield and the ex vivo amplification potential of MSCs obtained from various sources and different subjects, using defined culture conditions with a standardized platelet lysate (PL) as growth stimulus.

Methods

MSCs isolated from BM, UCT and AT and expanded in human PL were compared in terms of cumulative yield and growth potential per gram of starting tissue. MSCs morphology, phenotype, differentiation potential, and immunomodulatory properties were also investigated to evaluate their biological characteristics.

Results

The use of standardized PL-based culture conditions resulted in a very low variability of MSC growth. Our data showed that AT has the greater capacity to generate MSC per gram of initial tissue, compared to BM and UCT. However, UCT-MSCs replicated faster than AT-MSCs and BM-MSCs, revealing a greater proliferation capacity of this source irrespective of its lower MSC yield. All MSCs exhibited the typical MSC phenotype and the ability to differentiate into all mesodermal lineages, while BM-MSCs showed the most prominent immunosuppressive effect in vitro.

Conclusions

The adoption of standardized culture conditions may help researchers and clinicians to reveal particular characteristics and inter-individual variability of MSCs sourced from different tissues. These data will be beneficial to set the standards for tissue collection and MSCs clinical-scale expansion both for cell banking and for cell-based therapy settings.

Multidisciplinary approaches to stimulate wound healing

New civil wars and waves of terrorism are causing crucial social changes, with consequences in all fields, including health care. In particular, skin injuries are evolving as an epidemic issue. From a physiological standpoint, although wound repair takes place more rapidly in the skin than in other tissues, it is still a complex organ to reconstruct. Genetic and clinical variables, such as diabetes, smoking, and inflammatory/immunological pathologies, are also important risk factors limiting the regenerative potential of many therapeutic applications. Therefore, optimization of current clinical strategies is critical. Here, we summarize the current state of the field by focusing on stem cell therapy applications in wound healing, with an emphasis on current clinical approaches being developed. These involve protocols for the ex vivo expansion of adipose tissue-derived mesenchymal stem cells by means of a patented Good Manufacturing Practice-compliant platelet lysate. Combinations of multiple strategies, including genetic modifications and stem cells, biomimetic scaffolds, and novel vehicles, such as nanoparticles, are also discussed as future approaches.