Tiziana Montemurro

Molecular and phenotypic characterization of human amniotic fluid cells and their differentiation potential.

The main goal of the study was to identify a novel source of human multipotent cells, overcoming ethical issues involved in embryonic stem cell research and the limited availability of most adult stem cells. Amniotic fluid cells (AFCs) are routinely obtained for prenatal diagnosis and can be expanded in vitro; nevertheless current knowledge about their origin and properties is limited. Twenty samples of AFCs were exposed in culture to adipogenic, osteogenic, neurogenic and myogenic media. Differentiation was evaluated using immunocytochemistry, RT-PCR and Western blotting. Before treatments, AFCs showed heterogeneous morphologies. They were negative for MyoD, Myf-5, MRF4, Myogenin and Desmin but positive for osteocalcin, PPARgamma2, GAP43, NSE, Nestin, MAP2, GFAP and beta tubulin III by RT-PCR. The cells expressed Oct-4, Rex-1 and Runx-1, which characterize the undifferentiated stem cell state. By immunocytochemistry they expressed neural-glial proteins, mesenchymal and epithelial markers. After culture, AFCs differentiated into adipocytes and osteoblasts when the predominant cellular component was fibroblastic. Early and late neuronal antigens were still present after 2 week culture in neural specific media even if no neuronal morphologies were detectable. Our results provide evidence that human amniotic fluid contains progenitor cells with multi-lineage potential showing stem and tissue-specific gene/protein presence for several lineages.

Life-Sparing Effect of Human Cord Blood-Mesenchymal Stem Cells in Experimental Acute Kidney Injury

In search for new sources of mesenchymal stem cells (MSCs) for renal repair in acute kidney injury (AKI), we investigated the potential of human cord blood (CB)‐MSCs to cure mice with AKI. Infusion of CB‐MSCs in immunodeficient mice with cisplatin‐induced AKI ameliorated both renal function and tubular cell injury, and prolonged survival. Transplanted CB‐MSCs localized in peritubular areas, limited capillary alterations and neutrophil infiltration. Apoptosis reduced and tubular cell proliferation increased by virtue of stem cell capacity to produce growth factors. The reno‐protective effect of CB‐MSCs was further confirmed by their ability to inhibit oxidative damage and to induce the prosurvival factor Akt in tubular cells. The evidence that CB‐MSCs in vitro increased the production of growth factors and inhibited IL‐1β and TNFα synthesis when cocultured with damaged proximal tubular cells indicates a regenerative and anti‐inflammatory action of stem cell treatment. Altogether these results highlight the potential of human CB‐MSCs as future cell therapy for testing in human AKI. STEM CELLS 2010;28:513–522

Short-term, long-term and paracrine effect of human umbilical cord-derived stem cells in lung injury prevention and repair in experimental bronchopulmonary dysplasia

Background Bronchopulmonary dysplasia (BPD) remains a main complication of extreme prematurity and currently lacks efficient treatment. Rat bone marrow-derived mesenchymal stem cells (MSC) prevent lung injury in an oxygen-induced model of BPD. Human cord is an advantageous source of stem cells that is especially appealing for the treatment of neonatal diseases. The therapeutic benefit after established lung injury and long-term safety of cord-derived stem cells is unknown. Methods Human cord-derived perivascular cells (PCs) or cord blood-derived MSCs were delivered prophylactically or after established alveolar injury into the airways of newborn rats exposed to hyperoxia, a well-established BPD model. Results Rat pups exposed to hyperoxia showed the characteristic arrest in alveolar growth with air space enlargement and loss of lung capillaries. PCs and MSCs partially prevented and rescued lung function and structure. Despite therapeutic benefit, cell engraftment was low, suggesting that PCs and MSCs act via a paracrine effect. Accordingly, cell free-derived conditioned media from PCs and MSCs also exerted therapeutic benefit when used either prophylactically or therapeutically. Finally, long-term (6 months) assessment of stem cell or conditioned media therapy showed no adverse lung effects of either strategy, with persistent improvement in exercise capacity and lung structure. Conclusions Human umbilical cord-derived PCs and MSCs exert short- and long-term therapeutic benefit without adverse lung effects in this experimental model and offer new therapeutic options for lung diseases characterised by alveolar damage.

Differentiation and migration properties of human foetal umbilical cord perivascular cells: potential for lung repair

Mesenchymal stem cells (MSC) have been derived from different cultured human tissues, including bone marrow, adipose tissue, amniotic fluid and umbilical cord blood. Only recently it was suggested that MSC descended from perivascular cells, the latter being defined as CD146+ neuro‐glial proteoglycan (NG)2+ platelet‐derived growth factor‐Rβ+ ALP+ CD34– CD45– von Willebrand factor (vWF)– CD144–. Herein we studied the properties of perivascular cells from a novel source, the foetal human umbilical cord (HUC) collected from pre‐term newborns. By immunohistochemistry and flow cytometry we show that pre‐term/foetal HUCs contain more perivascular cells than their full‐term counterparts (2.5%versus 0.15%). Moreover, foetal HUC perivascular cells (HUCPC) express the embryonic cell markers specific embryonic antigen‐4, Runx1 and Oct‐4 and can be cultured over the long term. To further confirm the MSC identity of these cultured perivascular cells, we also showed their expression at different passages of antigens that typify MSC. The multilineage differentiative capacity of HUCPC into osteogenic, adipogenic and myogenic cell lineages was demonstrated in culture. In the perspective of a therapeutic application in chronic lung disease of pre‐term newborns, we demonstrated the in vitro ability of HUCPC to migrate towards an alveolar type II cell line damaged with bleomycin, an anti‐cancer agent with known pulmonary toxicity. The secretory profile exhibited by foetal HUCPC in the migration assay suggested a paracrine effect that could be exploited in various clinical conditions including lung disorders.

Cell Lines Derived from Human Parthenogenetic Embryos Can Display Aberrant Centriole Distribution and Altered Expression Levels of Mitotic Spindle Check-point Transcripts

Human parthenogenetic embryos have recently been proposed as an alternative, less controversial source of embryonic stem cell (ESC) lines; however many aspects related to the biology of parthenogenetic embryos and parthenogenetic derived cell lines still need to be elucidated. We present here results on human cell lines (HP1 and HP3) derived from blastocysts obtained by oocyte parthenogenetic activation. Cell lines showed typical ESC morphology, expressed Oct-4, Nanog, Sox-2, Rex-1, alkaline phosphatase, SSEA-4, TRA 1-81 and had high telomerase activity. Expression of genes specific for different embryonic germ layers was detected from HP cells differentiated upon embryoid body (EBs) formation. Furthermore, when cultured in appropriate conditions, HP cell lines were able to differentiate into mature cell types of the neural and hematopoietic lineages. However, the injection of undifferentiated HP cells in immunodeficient mice resulted either in poor differentiation or in tumour formation with the morphological characteristics of myofibrosarcomas. Further analysis of HP cells indicated aberrant levels of molecules related to spindle formation as well as the presence of an abnormal number of centrioles and autophagic activity. Our results confirm and extend the notion that human parthenogenetic stem cells can be derived and can differentiate in mature cell types, but also highlight the possibility that, alteration of the proliferation mechanisms may occur in these cells, suggesting great caution if a therapeutic use of this kind of stem cells is considered.

Adipogenic potential in human mesenchymal stem cells strictly depends on adult or foetal tissue harvest

Cell-based therapies promise important developments for regenerative medicine purposes. Adipose tissue and the adipogenic process has become central to an increasing number of translational efforts in addition to plastic and reconstructive surgical applications. In recent experimental clinical trials, human mesenchymal stem cells (MSC) have been proven to be well tolerated because of their low immunoreactivity. MSC are multipotent cells found among mature cells in different tissues and organs with the potentiality to differentiate in many cell types, including osteocytes, chondrocytes and adipocytes, thus being a suitable cell source for tissue engineering strategies. We compared the adipogenic potential of MSC originated from two adult sources as fat pads and bone marrow, and from four foetal sources as umbilical cord blood, Whartons jelly, amniotic fluid and preterm umbilical cord perivascular cells. Surprisingly, adult MSC displayed higher differentiation capacities confirmed by gene expression analysis on a selected panel of adipogenesis-related genes. Further, an in-depth molecular analysis highlighted the early and vigorous activation of the PPARγ transcription factor-cascade in adipose-derived MSC that resulted to be both delayed and reduced in foetal MSC accounting for their lack of adipogenic potential. Thus, MSC show a different degree of phenotypic plasticity depending on the source tissue, that should be taken into consideration for the selection of the most appropriate MSC type for specific tissue regeneration purposes.

Evaluation of the effect of cryopreservation on ex vivo expansion of hematopoietic progenitors from cord blood

In previous studies, we identified a cytokine cocktail including thrombopoietin, Flt-3 ligand, interleukin (IL)-6 and IL-11 in serum-free medium, suitable to induce significant and sustained ex vivo expansion of primitive hematopoietic stem cells (HSCs) from cord blood (CB) for up to 10 weeks. The aim of the present study was to evaluate the effects of cryopreservation on ex vivo expansion of HSCs and their committed progenitors. CD34+ cells were purified from CB units, each of which was processed in part as such and in part as cryopreserved and thawed, then expanded for 5 weeks in serum-free medium with the cytokine cocktail described above. We determined the number of nucleated cells (NC), CD34+, CD34+/38−/33−, CD34+/61+, CD61+ cells and the clonogenic potential. After 2 weeks the median fold expansion of NC, CD34+ and CD34+/38−/33− cells was around two log both with fresh and cryopreserved CB and the expansion continued similarly until week 5. Our data suggest that this serum free protocol induces similar ex vivo expansion of HSCs and their committed progenitors from both fresh and cryopreserved CB. Our findings can be useful in view of clinical applications, since CB used for transplantation is stored in the cryopreserved state. Bone Marrow Transplantation (2001) 28, 693–698.

Airway Fistula Closure after Stem-Cell Infusion

Investigators observed the healing of a broncholpeural fistula soon after the injection of mesenchymal stem cells into the area surrounding the fistula.

Autologous mesenchymal stem cell therapy for progressive supranuclear palsy: translation into a phase I controlled, randomized clinical study

BackgroundProgressive Supranuclear Palsy (PSP) is a sporadic and progressive neurodegenerative disease which belongs to the family of tauopathies and involves both cortical and subcortical structures. No effective therapy is to date available.Methods/designAutologous bone marrow (BM) mesenchymal stem cells (MSC) from patients affected by different type of parkinsonisms have shown their ability to improve the dopaminergic function in preclinical and clinical models. It is also possible to isolate and expand MSC from the BM of PSP patients with the same proliferation rate and immuphenotypic profile as MSC from healthy donors. BM MSC can be efficiently delivered to the affected brain regions of PSP patients where they can exert their beneficial effects through different mechanisms including the secretion of neurotrophic factors.Here we propose a randomized, placebo-controlled, double-blind phase I clinical trial in patients affected by PSP with MSC delivered via intra-arterial injection.DiscussionTo our knowledge, this is the first clinical trial to be applied in a no-option parkinsonism that aims to test the safety and to exploit the properties of autologous mesenchymal stem cells in reducing disease progression. The study has been designed to test the safety of this “first-in-man” approach and to preliminarily explore its efficacy by excluding the placebo effect.Trial registrationNCT01824121

Autologous hematopoietic stem cell transplantation has better outcomes than conventional therapies in patients with rapidly progressive systemic sclerosis.

We retrospectively evaluated the efficacy of autologous hematopoietic stem cell transplantation (AHSCT) in 18 patients with rapidly progressive diffuse cutaneous systemic sclerosis (rp-dcSSc), and compared their disease outcomes with those of 36 demographically- and clinically-matched patients treated with conventional therapies. Cutaneous involvement, by performing modified Rodnan skin score (mRss), lung diffusion capacity, by measuring diffusing capacity of lung for carbon monoxide (DLCO), and disease activity, by applying the European Scleroderma Study Group (ESSG) scoring system, were the outcome variables measured at the baseline time and then every 12 months for the following 60 months in both the AHSCT-treated patients and the control group. In the AHSCT group, treatment-related mortality was 5.6%. In this group, both mRss and ESSG scores showed a significant reduction 1 year after AHSCT (P<0.002); and these results were maintained until the end of follow-up. Conversely, DLCO values remained stable during the whole period of follow-up. Survival rate of AHSCT group was much higher than that observed in the whole control group (P=0.0005). The probability that the ESSG score and mRss would remain at a high level, and DLCO could decrease, was significantly higher in the control group as a whole and in the subgroup of control patients treated with cyclophosphamide than in the AHSCT group. This study confirms that the AHSCT is effective in prolonging survival, as well as in inducing a rapid reduction of skin involvement and disease activity, and preserving lung function in patients with rp-dcSSc.