Other articles by Simone Pacini on PubMed

• Bone and Bone Marrow Interactions: Hematological Activity of Osteoblastic Growth Peptide (OGP)-derived Carboxy-terminal Pentapeptide. II. Action on Human Hematopoietic Stem Cells Leukemia Research. Sep, 2002  |   Pubmed ID: 12127560 Osteogenic growth peptide (OGP) is a peptide exerting regulatory effects on the bone and on bone marrow. The carboxy-terminal pentapeptide (OGP10-14) is the biologically active portion of OGP. We evaluated OGP10-14 hematopoietic activity performing colony-forming tests on human stem cells derived by bone marrow, peripheral blood and cord blood. Granulocyte-macrophage colony-forming unit (CFU) were significantly increased in OGP10-14-treated samples, while granulocyte-erythrocyte-monocyte-megakaryocyte CFU and burst-forming unit (BFU) erythroid were increased only in the cord blood test.Moreover, OGP10-14 preserves stem cells self renewal potential in long-term culture (LTC) initiating cells and acts directly on CD34+ enriched cells or by increasing activity of stem cell factor (SCF) and granulocyte-megakaryocyte colony-stimulating factor.
• Carboxy-terminal Fragment of Osteogenic Growth Peptide in Vitro Increases Bone Marrow Cell Density in Idiopathic Myelofibrosis British Journal of Haematology. Apr, 2003  |   Pubmed ID: 12670334 Idiopathic myelofibrosis (IMF) is a clonal stem cell disorder characterized by reactive fibrosis of bone marrow sustained by a complex cytokine network. At present, no efficacious therapy for this disease exists. Synthetic carboxy-terminal pentapeptide of osteogenic growth factor (sOGP10-14) can increase bone marrow cellularity and the number of haematopoietic colonies; this study evaluated the activity of sOGP10-14 in IMF. Fragments of bone marrow biopsies from patients affected by IMF were cultured with or without the addition of sOGP10-14. Cellular density was evaluated by image analysis, and transforming growth factor-beta1 (TGF-beta1) concentration was immunologically assayed in the supernatant of cultured bone marrow biopsies. The proliferation rate of the megakaryoblastic M07-e cell line, cultured in the presence of either granulocyte-macrophage colony stimulating factor or thrombopoietin (TPO), and with or without sOGP10-14, was evaluated. Megakaryocyte colony forming unit (CFU-Mk) assay was performed on bone marrow samples of IMF patients with or without sOGP10-14. After 14 d, bone marrow cellularity was significantly increased in samples cultured with the pentapeptide. Moreover, sOGP10-14 induced a significant increase of TGF-beta in culture supernatants. TPO-primed proliferation of M07-e was reduced by sOGP10-14, and the pentapeptide significantly reduced CFU-Mk on IMF bone-marrow-derived cells. sOGP10-14 increased ex vivo bone marrow cellularity in IMF. This action could be related to the megakaryocyte inhibition induced by the interference of this pentapeptide with growth factor activities. These findings suggest that a deficiency of osteoblast-related factors may play a role in bone marrow failure in IMF.
• Bone and Bone Marrow Interactions: Hematological Activity of Osteoblastic Growth Peptide (OGP)-derived Carboxy-terminal Pentapeptide III. Action on Human Megakaryocytopoiesis: Focus on Essential Thrombocythemia Leukemia Research. Oct, 2004  |   Pubmed ID: 15289024 The increase of megakaryocytes and platelets that characterizes essential thrombocythemia (ET) appears to be secondary to a deregulation of megakaryocytopoiesis. The carboxy-terminal fragment of osteogenic growth peptide (OGP10-14) promotes bone formation and hemopoiesis, while it inhibits megakaryocytopoiesis. In this paper we show that treatment with synthetic OGP10-14 (sOGP10-14) induces a significant reduction of mid and large colony-forming unit-megakaryocytes (CFU-Mk) in ET patients as well as in controls, and is associated with a significant inhibition of thrombopoietin (TPO)-primed MO-7e megakaryoblastic cells proliferation. These actions appear to be related to sOGP10-14 modulation of TGF-beta(1) synthesis and/or secretion, although a direct effect on TGF-beta receptor expression cannot be excluded.
• Quantitative Molecular Evaluation of Minimal Residual Disease in Patients with Chronic Lymphocytic Leukemia: Efficacy of in Vivo Purging by Alemtuzumab (Campath-1H) Journal of Immunotherapy (Hagerstown, Md. : 1997). Sep-Oct, 2004  |   Pubmed ID: 15314547 Although novel therapies for chronic lymphocytic leukemia have resulted in higher hematologic response rates, the complete eradication of disease rarely occurs. Alemtuzumab (Campath-1H) seems to be extremely effective in this role in pretreated patients. The authors used a molecular semiquantitative polymerase chain reaction (PCR) method to assess the ability of alemtuzumab to induce PCR negativity in eight patients pretreated with fludarabine. IgH rearrangement was coamplified with a housekeeping gene and fluorescent PCR products were analyzed on a DNA automatic sequencer. Each patient was evaluated at diagnosis, after fludarabine, and after Campath-1H. The median interval between the last therapy course with fludarabine and the start of Campath-1H was 14 weeks. Patients received subcutaneous doses up to 10 mg, three times a week, for 12 weeks, with a median dose of 190 mg. After six cycles with fludarabine, only one patient (12.5%) achieved molecular remission, and in three other patients IgH levels decreased by 0.5 to 1 log. At the beginning of Campath-1H administration, all patients were PCR positive, including the one previously found to be negative. At the end of treatment, five patients achieved molecular remission (62.5%), four of them within 1 month after the end of therapy. Seventy-two percent of responses, with 43% of complete responses, were documented on bone marrow smears. A significant reduction of lymph node and spleen diameters was noted in 50% and 33% of patients, respectively. Four patients showed grade 2 skin reaction at the site of the subcutaneous injection and grade 1 or 2 fever. Two patients developed neutropenia (grade 2 and 3) and two hemolytic episodes. Three patients showed cytomegalovirus and one herpes zoster and Epstein-Barr virus reactivation. These results show that Campath-1H represents an efficacious in vivo purging tool with a safe profile.
• Carboxy-terminal Fragment of Osteogenic Growth Peptide Regulates Myeloid Differentiation Through RhoA Journal of Cellular Biochemistry. Dec, 2004  |   Pubmed ID: 15486974 The carboxy-terminal fragment of osteogenic growth peptide, OGP(10-14), is a pentapeptide with bone anabolic effects and hematopoietic activity. The latter activity appears to be largely enhanced by specific growth factors. To study the direct activity of OGP(10-14) on myeloid cells, we tested the pentapeptide proliferating/differentiating effects in HL60 cell line. In this cell line, OGP(10-14) significantly inhibited cell proliferation, and enhanced myeloperoxidase (MPO) activity and nitroblue tetrazolium reducing ability. Moreover, it induced cytoskeleton remodeling and small GTP-binding protein RhoA activation. RhoA, which is known to be involved in HL60 differentiation, mediated these effects as shown by using its specific inhibitor, C3. Treatment with GM-CSF had a comparable OGP(10-14) activity on proliferation, MPO expression, and RhoA activation. Further studies on cell proliferation and RhoA activation proved enhanced activity by association of the two factors. These results strongly suggest that OGP(10-14) acts directly on HL60 cells by activating RhoA signaling although other possibilities cannot be ruled out.
• Quantitative Molecular Monitoring of BCR-ABL and MDR1 Transcripts in Patients with Chronic Myeloid Leukemia During Imatinib Treatment Cancer Genetics and Cytogenetics. Oct, 2005  |   Pubmed ID: 16157201 Different mechanisms could sustain Imatinib resistance, including overexpression of MDR1, a gene already known to be responsible for multidrug resistance in other hematologic malignancies. In search for a possible correlation, BCR-ABL and MDR1 expression were measured in 115 serial bone marrow samples from 33 CML patients during Imatinib treatment. All patients achieved complete hematologic responses, and 22 patients also achieved complete cytogenetic responses, with median BCR-ABL mRNA values significantly lower than those observed in the group of cases that were persistently Philadelphia positive. All three cases treated during the accelerated phase showed disease progression after an initial period of remission; all presented either increased levels of BCR-ABL or MDR1 3 months before clinical progression. In the subgroup of cases treated during the chronic phase, BCR-ABL and MDR1 levels were significantly correlated after 3 and 6 months (88 and 80%, respectively) but not after 12 months of treatment (32%). Reported data maintain that MDR1 expression would play an important role in Imatinib resistance when the disease is not fully controlled (e.g., progressive disease or during the first months of treatment).
• Chimerism Does Not Influence Graft-versus-myeloma and Graft-versus-host Disease in Reduced Intensity Setting Transplant Immunology. Dec, 2005  |   Pubmed ID: 16412962 In this study we serially evaluated the chimerism status in 20 multiple myeloma patients allotransplanted with a reduced intensity regimen. All patients engrafted, with total 75% overall responses and 35% of CRs. After a median follow-up of 35 months, seven patients (35%) died, three of them due to disease progression. Four patients died before day +100, with a TRM of 20%. Nine patients (45%) developed aGVHD and six (40%) had cGVHD. Twenty-five percent of patients achieved full donor chimerism (FDC) before day +100, 42% before day +200 and 75% 24 months after graft. In our series, level of chimerism did not correlate with either the quality of response or aGVHD. No significant differences were found between bone marrow and peripheral blood samples. Analogously, even if donor DNA percentage often resulted higher in the PMN fraction than in the mononuclear one, these differences were not significant after statistical analysis. On the other hand, cGVHD was associated with increased rates of FDC, with 6/6 cases showing a full donor pattern in concomitance of the cGVHD versus 5/9 cases presenting a FDC in the group of patients without cGVHD (p=0.057). The Kaplan-Meier estimates of OS and PFS at 2 years were 59% and 58%, respectively; chimerism pattern did not impact in the predicting clinical outcome. In summary, our study shows that a stable engraftment and high frequency of donor chimerism are achievable after a reduced intensity conditioning regimen. Moreover, even as result of a single center experience, we suggest that chimerism, graft-versus-myeloma and GVHD would represent distinct entities that require larger immunological studies for further clarification.
• Primary Lymphoma of the Bladder: Case Report American Journal of Hematology. Jan, 2006  |   Pubmed ID: 16369978
• RAF-1 Over-expression Does Condition Survival of Patients Affected by Aggressive Mantle Cell Lymphoma Leukemia Research. Nov, 2007  |   Pubmed ID: 17572489
• Evaluation of the MDR1, ABCG2, Topoisomerases IIalpha and GSTpi Gene Expression in Patients Affected by Aggressive Mantle Cell Lymphoma Treated by the R-Hyper-CVAD Regimen Leukemia & Lymphoma. Aug, 2007  |   Pubmed ID: 17701580 The genomic profile of mantle cell lymphoma (MCL) has been reported to be significantly different from that of other indolent lymphoproliferative disorders, Topoisomerase IIalpha, glutathione-s-transferasepi (GSTpi) and ABCG2 (BCRP) chemoresistance genes being over-expressed in MCL. In our study, expression levels of the above mentioned genes plus MDR1 were tested on bone marrow samples from 20 patients treated with Rituximab plus hyper-CVAD regimen, in order to evaluate a possible impact of the chemoresistance phenomenon on this promising treatment regimen. All patients expressed ABCG2 and MDR1 genes; 85% of cases expressed GSTpi and topoisomerase IIalpha. Only ABCG2 were over-expressed in comparison both with marrow from healthy donors and tonsilar CD5+/CD20+ lymphocytes (adopted as normal counterpart of the neoplastic population). The overall response rate of the entire series was 87.5%, with 44% of complete responses. Fifty-seven percent of patients achieved the clearance of minimal residual disease. Levels of tested genes did not condition either quality of clinical response or PFS (76% at 24 months). Nevertheless, an ABCG2 higher expression appeared associated with a worse PFS and levels of this gene paralleled the status of minimal residual disease. A further evaluation of ABCG2 expression in larger series of MCL patients would be suitable.
• Suspension of Bone Marrow-derived Undifferentiated Mesenchymal Stromal Cells for Repair of Superficial Digital Flexor Tendon in Race Horses Tissue Engineering. Dec, 2007  |   Pubmed ID: 17919069 It has been proven that mesenchymal stromal cells (MSCs) can differentiate into tenocytes. Attempts to repair tendon lesions have been performed, mainly using scaffold carriers in experimental settings. In this article, we describe the clinical use of undifferentiated MSCs in racehorses. Significant clinical recovery was achieved in 9 of 11 horses evaluated using ultrasound analysis and their ability to return to racing. Our results show that the suspension of a small number of undifferentiated MSCs may be sufficient to repair damaged tendons without the use of scaffold support. Ultrasound scanning showed that fibers were correctly oriented. By using undifferentiated cells, no ectopic bone deposition occurred. A sufficient number of cells was recovered for therapeutic purposes in all but 1 case. We suggest that the use of autologous MSCs is a safe therapeutic method for treating incompletely (i.e., not full-thickness) damaged tendons.
• Human Autologous Plasma-derived Clot As a Biological Scaffold for Mesenchymal Stem Cells in Treatment of Orthopedic Healing Journal of Orthopaedic Research : Official Publication of the Orthopaedic Research Society. Feb, 2008  |   Pubmed ID: 17868116 Recent advances in the isolation, expansion, and characterization of human mesenchymal stem cells (hMSCs) have raised the possibility of using them in cell therapies and tissue engineering for bone reconstruction. hMSCs, isolated from the bone marrow of eight normal adult patients, were minimally expanded ex vivo and pulsed twice toward osteogenic lineage. The cells were then included into autologous plasma-derived clots. Cytofluorimetric analysis, immunocytochemistry (osteopontin), histochemistry (alkaline phosphatase, Alcian blue, Von Kossa, and alizarin red staining), and viable/proliferation tests were performed to study both stem and differentiating cells. Although two short inductions increased osteogenic markers in hMSCs, inside the clot the cells were able to terminally differentiate into osteoblasts. Moreover, we show that the clot is able to sustain cell proliferation under appropriate cell culture conditions. Our results suggested that clot could be useful for hMSC delivery into the site of the lesion to promote bone formation. Moreover, the plasticity of this material allowed good in vitro hMSC spreading and proliferation. The advantages of using this autologous biological material are its biocompatibility and reabsorption; furthermore, using a gel as scaffold, it is possible to mold it to the shape of a bone cavity.
• Gelatin/PLLA Sponge-like Scaffolds Allow Proliferation and Osteogenic Differentiation of Human Mesenchymal Stromal Cells Macromolecular Bioscience. Sep, 2008  |   Pubmed ID: 18504804 Tissue engineering has the potential to supply constructs capable of restoring the normal function of native tissue following injury. Poly(L-lactic acid) (PLLA) scaffolds are amongst the most commonly used biodegradable polymers in tissue engineering and previous studies performed on ovine fibroblasts have showed that addition of gelatin creates a favorable hydrophilic microenvironment for the growth of these cells. The attractiveness of using mesenchymal stromal cells (MSCs) in tissue regeneration is that they are able to differentiate into several lines including osteoblasts. In this study, we investigated the ability of gelatin/PLLA sponges to support the adhesion, proliferation, and osteogenic differentiation of human MSCs isolated from the bone marrow of four donors. [Figure: see text].
• Good Manufacturing Practice-grade Fibrin Gel is Useful As a Scaffold for Human Mesenchymal Stromal Cells and Supports in Vitro Osteogenic Differentiation Transfusion. Oct, 2008  |   Pubmed ID: 18657082 Recently, there has been an increased interest in using mesenchymal stromal cells (MSCs) in bone tissue engineering coupled with a suitable scaffold of both biological and synthetic origin. The cells and these constructs can be combined in vitro or directly in vivo to enhance tissue repair. MSCs are spindle-shaped cells capable of self-renewal and can be induced to differentiate mainly into osteo-, chondro-, and adipogenic-progeny types. Several biomaterials are currently available and, among them, fibrin-based constructs seem to be suitable for guiding the cells during tissue repair or regeneration due to their biocompatibility and biodegradability.
• Identification and Purification of Mesodermal Progenitor Cells from Human Adult Bone Marrow Stem Cells and Development. Jul-Aug, 2009  |   Pubmed ID: 18991503 Bone marrow-derived mesodermal stem cells may differentiate toward several lines and are easily cultured in vitro. Some putative progenitors of these cells have been described in both humans and mice. Here, we describe a new mesodermal progenitor population [mesodermal progenitors cells (MPCs)] able to differentiate into mesenchymal cells upon appropriate culture conditions. When cultured in presence of autologous serum, these cells are strongly adherent to plastic, resistant to trypsin detachment, and resting. Mesodermal progenitor cells may be pulsed to proliferate and differentiate by substituting autologous serum for human cord blood serum or fetal calf serum. By these methods cells proliferate and differentiate toward mesenchymal cells and thus may further differentiate into osteoblats, chondrocytes, or adipocytes. Moreover MPCs are capable to differentiate in endothelial cells (ECs) showing characteristics similar to microvessel endothelium cells. Mesodermal progenitors cells have a defined phenotype and carry embryonic markers not present in mesenchymal cells. Moreover MPCs strongly express aldehyde dehydrogenase activity, usually present in hematopoietic precursors but absent in mesenchymal cells. When these progenitors are pulsed to differentiate, they lose these markers and acquire the mesenchymal ones. Interestingly, mesenchymal cells may not be induced to back differentiate into MPCs. Our results demonstrate the adult serum role in maintaining pluripotent mesodermal precursors and allow isolation of these cells. After purification, MPCs may be pulsed to proliferate in a very large scale and then induced to differentiate, thus possibly allowing their use in regenerative medicine.
• Selective Culture of Mesodermal Progenitor Cells Stem Cells and Development. Oct, 2009  |   Pubmed ID: 19331526 We have recently identified mesodermal progenitor cells (MPCs) isolated from adult human bone marrow. These cells show unusual phenotypes, having putative embryonic markers and aldehyde dehydrogenase (ALDH) activity. Interestingly, these resting cells, which have been selected by culturing them in the presence of adult human serum, can easily be induced to differentiate into mature mesenchymal stromal cells (MSCs) after substituting the adult human serum for fetal bovine serum (FBS) or human cord serum. MPC-derived MSCs are, in turn, able to differentiate toward osteoblasts, chondrocytes, and adipocytes. Furthermore, MPCs are able to differentiate into endothelial cells. MPCs have been proven to be strongly adherent to plastic culture bottles and to be trypsin-resistant. In the present article, we show a simple and inexpensive method to isolate highly selected mesodermal progenitors from bone marrow or cord blood. The optimization of standard culture conditions (using commercial human AB sera and appropriate concentrations for cell seeding in plastics) allows a pure population of MPCs to be obtained even after a short culture period. We believe that this simple, repeatable, and standardized method will facilitate studies on MPCs.
• Constitutive Expression of Pluripotency-associated Genes in Mesodermal Progenitor Cells (MPCs) PloS One. 2010  |   Pubmed ID: 20360837 We recently characterized a progenitor of mesodermal lineage (MPCs) from the human bone marrow of adults or umbilical cord blood. These cells are progenitors able to differentiate toward mesenchymal, endothelial and cardiomyogenic lineages. Here we present an extensive molecular characterization of MPCs, from bone marrow samples, including 39 genes involved in stem cell machinery, differentiation and cell cycle regulation.
• Mesodermal Progenitor Cells (MPCs) Differentiate into Mesenchymal Stromal Cells (MSCs) by Activation of Wnt5/calmodulin Signalling Pathway PloS One. 2011  |   Pubmed ID: 21980498 Mesenchymal Stromal Cells (MSCs) remain poorly characterized because of the absence of manifest physical, phenotypic, and functional properties in cultured cell populations. Despite considerable research on MSCs and their clinical application, the biology of these cells is not fully clarified and data on signalling activation during mesenchymal differentiation and proliferation are controversial. The role of Wnt pathways is still debated, partly due to culture heterogeneity and methodological inconsistencies. Recently, we described a new bone marrow cell population isolated from MSC cultures that we named Mesodermal Progenitor Cells (MPCs) for their mesenchymal and endothelial differentiation potential. An optimized culture method allowed the isolation from human adult bone marrow of a highly pure population of MPCs (more than 97%), that showed the distinctive SSEA-4+CD105+CD90(neg) phenotype and not expressing MSCA-1 antigen. Under these selective culture conditions the percentage of MSCs (SSEA-4(neg)CD105+CD90(bright) and MSCA-1+), in the primary cultures, resulted lower than 2%.
• Impaired Function of Gamma-delta Lymphocytes in Melanoma Patients European Journal of Clinical Investigation. Nov, 2011  |   Pubmed ID: 22775565 Melanoma is an immunogenic tumour but, despite the wide range of immunotherapies tested, only few promising results have been reported to date. Both in vitro and in xenograft models, γδ lymphocyte-mediated cytotoxicity against melanoma cells has been reported. IL-2/zoledronate treatment can expand γδ cells in vitro and in animal models. This could represent an immunotherapeutic strategy against melanoma. To evaluate the feasibility of this approach, we studied γδ lymphocyte phenotype from patients with melanoma, their ability to be expanded by IL-2/zoledronate and their cytotoxic activity against SK-MEL-30 cell line.
• Endothelial Differentiation of Mesenchymal Stromal Cells: when Traditional Biology Meets Mechanotransduction Integrative Biology : Quantitative Biosciences from Nano to Macro. Feb, 2013  |   Pubmed ID: 23086215 In the last few years, scientists have focused their attention on adult stem cells. It has long been known that stem cells are capable of renewing themselves and can generate multiple cell types. Today, it is demonstrated that stem cells are present in far more tissues and organs than once thought and that they are capable of developing into more kinds of cells than previously imagined. Adult human mesenchymal stromal cells (h-MSC) are prime candidates for many cell-based tissue-engineering applications thanks to their plasticity and easy accessibility. Despite such potential, their use in therapeutic application is still restricted because there are some open issues, which need to be deeply investigated. In this review, we focus on endothelial differentiation of h-MSCs. We comment on some controversies and show how these might arise from h-MSCs heterogeneity and morpho-functional variability. Finally, we highlight the role of extracellular mechanical cues and report on the mechanotransduction pathways activated by micro-/nanotopographies as promising alternative differentiation inducers.
• Specific Integrin Expression is Associated with Podosome-like Structures on Mesodermal Progenitor Cells Stem Cells and Development. Jun, 2013  |   Pubmed ID: 23379672 Mesenchymal stromal cells (MSCs) are a heterogeneous cell population capable of differentiating toward several cell lines in vitro and, possibly, in vivo. Within cultured MSCs, we identified and purified a precursor cell population [mesodermal progenitor cells (MPCs)] retaining robust proliferation potential and ability to differentiate into endothelial or mesenchymal cells. MPC-derived MSCs retain the ability to further differentiate into osteoblasts, cartilage, or fat cells. Here we further characterized MPCs and MSCs by evaluating expression of integrins and adhesion molecules showing their ability to assemble the molecular machinery involved in endothelium adhesion. MPCs were shown to interact with activated and nonactivated endothelium, whereas MSCs exhibited activation of focal adhesion complexes, higher cell motility, and reduced or absent adhesiveness onto endothelial cells, suggesting a matrix remodeling vocation. We also reported a consistent expression of CXCR4 on the MPC cell surface, suggesting that the different phenotypic behavior could be related to specific functions of the cell in each differentiation stage.
• Plasticity of Human Dental Pulp Stromal Cells with Bioengineering Platforms: a Versatile Tool for Regenerative Medicine Micron (Oxford, England : 1993). Dec, 2014  |   Pubmed ID: 25180486 In recent years, human dental pulp stromal cells (DPSCs) have received growing attention due to their characteristics in common with other mesenchymal stem cells, in addition to the ease with which they can be harvested. In this study, we demonstrated that the isolation of DPSCs from third molar teeth of healthy individuals allowed the recovery of dental mesenchymal stem cells that showed self-renewal and multipotent differentiation capability. DPSCs resulted positive for CD73, CD90, CD105, STRO-1, negative for CD34, CD45, CD14 and were able to differentiate into osteogenic and chondrogenic cells. We also assayed the angiogenic potential of DPSCs, their capillary tube-like formation was assessed using an in vitro angiogenesis assay and the uptake of acetylated low-density lipoprotein was measured as a marker of endothelial function. Based on these results, DPSCs were capable of differentiating into cells with phenotypic and functional features of endothelial cells. Furthermore, this study investigated the growth and differentiation of human DPSCs under a variety of bioengineering platforms, such as low frequency ultrasounds, tissue engineering and nanomaterials. DPSCs showed an enhanced chondrogenic differentiation under ultrasound application. Moreover, DPSCs were tested on different scaffolds, poly(vinyl alcohol)/gelatin (PVA/G) sponges and human plasma clots. We showed that both PVA/G and human plasma clot are suitable scaffolds for adhesion, growth and differentiation of DPSCs toward osteoblastic lineages. Finally, we evaluated the interactions of DPSCs with a novel class of nanomaterials, namely boron nitride nanotubes (BNNTs). From our investigation, DPSCs have appeared as a highly versatile cellular tool to be employed in regenerative medicine.
• Are MSCs Angiogenic Cells? New Insights on Human Nestin-positive Bone Marrow-derived Multipotent Cells Frontiers in Cell and Developmental Biology. 2014  |   Pubmed ID: 25364727 Recent investigations have made considerable progress in the understanding of tissue regeneration driven by mesenchymal stromal cells (MSCs). Data indicate the anatomical location of MSC as residing in the "perivascular" space of blood vessels dispersed across the whole body. This histological localization suggests that MSCs contribute to the formation of new blood vessels in vivo. Indeed, MSCs can release angiogenic factors and protease to facilitate blood vessel formation and in vitro are able to promote/support angiogenesis. However, the direct differentiation of MCSs into endothelial cells is still matter of debate. Most of the conflicting data might arise from the presence of multiple subtypes of cells with heterogeneous morpho functional features within the MSC cultures. According to this scenario, we hypothesize that the presence of the recently described Mesodermal Progenitor Cells (MPCs) within the MSCs cultures is responsible for their variable angiogenic potential. Indeed, MPCs are Nestin-positive CD31-positive cells exhibiting angiogenic potential that differentiate in MSC upon proper stimuli. The ISCT criteria do not account for the presence of MPC within MSC culture generating confusion in the interpretation of MSC angiogenic potential. In conclusion, the discovery of MPC gives new insight in defining MSC ancestors in human bone marrow, and indicates the tunica intima as a further, and previously overlooked, possible additional source of MSC.
• Deterministic and Stochastic Approaches in the Clinical Application of Mesenchymal Stromal Cells (MSCs) Frontiers in Cell and Developmental Biology. 2014  |   Pubmed ID: 25364757 Mesenchymal stromal cells (MSCs) have enormous intrinsic clinical value due to their multi-lineage differentiation capacity, support of hemopoiesis, immunoregulation and growth factors/cytokines secretion. MSCs have thus been the object of extensive research for decades. After completion of many pre-clinical and clinical trials, MSC-based therapy is now facing a challenging phase. Several clinical trials have reported moderate, non-durable benefits, which caused initial enthusiasm to wane, and indicated an urgent need to optimize the efficacy of therapeutic, platform-enhancing MSC-based treatment. Recent investigations suggest the presence of multiple in vivo MSC ancestors in a wide range of tissues, which contribute to the heterogeneity of the starting material for the expansion of MSCs. This variability in the MSC culture-initiating cell population, together with the different types of enrichment/isolation and cultivation protocols applied, are hampering progress in the definition of MSC-based therapies. International regulatory statements require a precise risk/benefit analysis, ensuring the safety and efficacy of treatments. GMP validation allows for quality certification, but the prediction of a clinical outcome after MSC-based therapy is correlated not only to the possible morbidity derived by cell production process, but also to the biology of the MSCs themselves, which is highly sensible to unpredictable fluctuation of isolating and culture conditions. Risk exposure and efficacy of MSC-based therapies should be evaluated by pre-clinical studies, but the batch-to-batch variability of the final medicinal product could significantly limit the predictability of these studies. The future success of MSC-based therapies could lie not only in rational optimization of therapeutic strategies, but also in a stochastic approach during the assessment of benefit and risk factors.
• Combination of CD157 and FLAER to Detect Peripheral Blood Eosinophils by Multiparameter Flow Cytometry Journal of Clinical and Experimental Hematopathology : JCEH. 2015  |   Pubmed ID: 26490516 The identification of eosinophils by flow cytometry is difficult because most of the surface antigens expressed by eosinophils are shared with neutrophils. Some methods have been proposed, generally based on differential light scatter properties, enhanced autofluorescence, lack of CD16 or selective positivity of CD52. Such methods, however, show several limitations. In the present study we report a novel method based on the analysis of glycosylphosphatidylinositol (GPI)-linked molecules. The combination of CD157 and FLAER was used, since FLAER recognizes all GPI-linked molecules, while CD157 is absent on the membrane of eosinophils and expressed by neutrophils. Peripheral blood samples from normal subjects and patients with variable percentages of eosinophils (n = 31), and without any evidence for circulating immature myeloid cells, were stained with the combination of FLAER-Alexa Fluor and CD157-PE. A FascCanto II cytometer was used. Granulocytes were gated after CD33 staining and eosinophils were identified as CD157(-)/FLAER(+) events. Neutrophils were identified as CD157(+)/FLAER(+) events. The percentages of eosinophils detected by this method showed a very significant correlation both with automated counting and with manual counting (r = 0.981 and 0.989, respectively). Sorting assays were carried out by a S3 Cell Sorter: cytospins obtained from CD157(-)/FLAER(+) events consisted of 100% eosinophils, while samples from CD157(+)/FLAER(+) events were represented only by neutrophils. In conclusion, this method shows high sensitivity and specificity in order to distinguish eosinophils from neutrophils by flow cytometry. However, since CD157 is gradually up-regulated throughout bone marrow myeloid maturation, our method cannot be applied to cases characterized by immature myeloid cells.
• Mesangiogenic Progenitor Cells Derived from One Novel CD64(bright)CD31(bright)CD14(neg) Population in Human Adult Bone Marrow Stem Cells and Development. May, 2016  |   Pubmed ID: 26975798 Mesenchymal stromal cells (MSCs) have been the object of extensive research for decades, due to their intrinsic clinical value. Nonetheless, the unambiguous identification of a unique in vivo MSC progenitor is still lacking, and the hypothesis that these multipotent cells could possibly arise from different in vivo precursors has been gaining consensus in the last years. We identified a novel multipotent cell population in human adult bone marrow that we first named Mesodermal Progenitor Cells (MPCs) for the ability to differentiate toward the mesenchymal lineage, while still retaining angiogenic potential. Despite extensive characterization, MPCs positioning within the differentiation pathway and whether they can be ascribed as possible distinctive progenitor of the MSC lineage is still unclear. In this study, we describe the ex vivo isolation of one novel bone marrow subpopulation (Pop#8) with the ability to generate MPCs. Multicolor flow cytometry in combination with either fluorescence-activated cell sorting or magnetic-activated cell sorting were applied to characterize Pop#8 as CD64(bright)CD31(bright)CD14(neg). We defined Pop#8 properties in culture, including the potential of Pop#8-derived MPCs to differentiate into MSCs. Gene expression data were suggestive of Pop#8 in vivo involvement in hematopoietic stem cell niche constitution/maintenance. Pop#8 resulted over three logs more frequent than other putative MSC progenitors, corroborating the idea that most of the controversies regarding culture-expanded MSCs could be the consequence of different culture conditions that select or promote particular subpopulations of precursors.