Isolation of bone marrow mesenchymal stem cells by anti-nerve growth factor receptor antibodies

OBJECTIVE: Mesenchymal stem cells (MSCs) are a population of multipotent cells that can proliferate and differentiate into multiple mesodermal tissues. We previously reported that monoclonal antibodies to the low-affinity nerve growth factor receptor (alpha-LNGFR) stain bone marrow (BM) mesenchymal cells. We now show that LNGFR antibodies label primitive MSCs with high specificity and purity in adult BM, and compare these cells to those isolated by plastic adherence (PA) and CD45(-)anti-glycophorin A(-) selection. MATERIALS AND METHODS: Low-density mononuclear cells (LD-MNCs) from normal BM were separated by PA or immunomagnetic selection for NGFR(+) or CD45(-)alpha-glycophorin A(-) cells. The three fractions were grown in Iscove's modified Dulbecco medium + 20% fetal bovine serum +/- basic fibroblast growth factor (bFGF) in order to assess their proliferative capacity and evaluate their phenotype during culture. The clonogenic potential of the MSCs was assessed using a colony-forming unit fibroblast (CFU-F) assay, whereas multipotential differentiation was determined after culture in adipocytic and osteoblastic conditioned media. RESULTS: The NGFR(+) mesenchymal cells grown without growth factors showed persistent NGFR expression (rapidly down-regulated after the addition of bFGF) and persistent CFU-F activity. The NGFR(+) fractions were rich in clonogenic precursors: CFU-F median frequency was 1584/1 x 10(6) cells (range 325-13,793) in the NGFR(+) cells and 35/1 x 10(6) cells (range 27-112) in the LD-MNCs. The NGFR(-) fraction never showed any residual CFU-F activity. Compared with the other two fractions, the NGFR(+) cells (+/- bFGF) showed a 1 to 3 log greater expansion in the number of fibroblastic cells and a greater capacity to give rise to adipocyte colonies and induce osteoblastic differentiation, and they had similar effects in supporting the growth of hematopoietic precursors. CONCLUSION: The data suggest that positive selection using low-affinity NGFR antibodies makes it possible to obtain homogeneous multipotent MSCs.     

Prognostic relevance of histological findings on bone marrow biopsy in myelodysplastic syndromes

Summary Bone marrow biopsy (BMB) has aroused growing interest as a possible aid in the diagnostic and prognostic evaluation of myelodysplastic syndromes (MDS). Previous reports have pointed out that MDS patients with blastic aggregates or severe bone marrow (BM) fibrosis are characterized by a worse clinical outcome. BMBs of 106 MDS patients were retrospectively reviewed, and relationships among the different histological parameters as well as clinicopathological correlations were looked for. Three patterns of BM blastic infiltration (diffuse, cluster, and large) were recognized. Overt leukemic transformation and overall survival were selected as prognostic end points. BM infiltration was diffuse in 18, cluster in 48, and large in 40 cases. RAEB-t patients accounted for about half of the large cases, and none had a diffuse pattern (p<0.01). Nineteen patients showed extensive BM fibrosis; most of them were characterized by cluster blastic infiltration and megakaryocyte hyperplasia. Leukemic transformation occurred in 67% of large cases (p<0.001) and in none of the cluster cases with severe BM fibrosis (p<0.01); however, survival was equally poor in these two groups because of early leukemic transformation (large cases) and BM failure (cluster cases). The FAB classification did not significantly correlate with prognosis. Patients with cluster BM infiltration and severe fibrosis can be regarded as a true separate MDS subset characterized by unique clinicopathological and prognostic features. Because of the subacute clinical behavior of most cases, and the poor performance status of many elderly patients, there is still controversy as to the best therapeutic approach in MDS. Histological analysis allowed two groups of MDS patients to be identified, both characterized by poor life expectancy, who could benefit from early aggressive chemotherapy.     

Retrovirus-mediated transfer of the multidrug resistance gene into human haemopoietic progenitor cells

Summary. We report the utilization of cord blood (CB) or bone marrow (BM) derived low density or purified CD34⁺ cells as a target for human multidrug resistance (MDR1) gene transfer, Cells were cocultivated for 48 h with an irradiated MDR1 retroviral producer line. Since some degree of MDR1 gene expression has been reported to occur in haemopoietic progenitor cells and in peripheral blood cells, effciency of MDR1 gene transfer was assessed by: (1) Drug selection and culture in presence of 50 ng/ml doxorubicin, 10 ng/ml colchicine and 0.85 μg/ml taxol. In uninfected control, 1–2% of CFU-GM and CFU-GEMM were found to be drug-resistant, while 14–31% of original clonogenic activity was found after 2 weeks of culture of transduced cells. Efficiency of MDR1 transfer was significantly enhanced by prestimulation with cytokines, and found to be significantly superior in CB-derived compared to BM-derived progenitors. (2) Analysis of MDR1 gene expression by evaluating MDR1 mRNA through polymerase chain reaction. MDR1 expression was very low in cultures of uninfected controls, whereas, after drug selection, MDR1 mRNA levels in transduced cells was as high as in the MDR1 retroviral producer line (positive controls). (3) Flow cytometiric analysis of the expression of CD34 and P-glycoprotein, the product of the MDR1 gene. After MDR1 transduction and 2 weeks of culture, membrane expression of P-glycoprotien, was found on 17–25% of viable CD34⁺ cells. (4) Cytochemical localization by APAAP staining of P-glycoprotein. No specific localization was found in untransduced controls, whereas transduced and cultured CB-cells expressed P-glycoprotein on plasma and nuclei membrane. In conclusion, MDR1 gene transfer into CB- and BM-derived progenitor cells seems a feasible and attractive approach to generate a drug-resistant haemopoiesis.     

Angiogenesis occurs in hairy cell leukaemia (HCL) and in NOD/SCID mice transplanted with the HCL line Bonna-12

Microvessel density (MVD), a surrogate marker for angiogenesis, was evaluated by anti-CD34 and CD105 monoclonal antibodies (Abs), and found to be increased in the bone marrow (BM) of hairy cell leukaemia (HCL) patients and in a preclinical model of non-obese diabetic/severe combined immunodeficient mice transplanted with the HCL line Bonna-12. The anti-CD105 Ab was significantly more sensitive than anti-CD34 Ab in identifying blood vessels. The BM tumour burden significantly decreased in patients treated with interferon-alpha, but the mean value of MVD remained unchanged. These data suggest that angiogenesis may be involved in the pathogenesis of HCL.     

Differentiation and expansion of endothelial cells from human bone marrow CD133+ cells

We report a method of purifying, characterizing and expanding endothelial cells (ECs) derived from CD133(+) bone marrow cells, a subset of CD34(+) haematopoietic progenitors. Isolated using immunomagnetic sorting (mean purity 90 +/- 5%), the CD133(+) bone marrow cells were grown on fibronectin-coated flasks in M199 medium supplemented with fetal bovine serum (FBS), vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF) and insulin growth factor (IGF-1). The CD133(+) fraction contained 95 +/- 4% CD34(+) cells, 3 +/- 2% cells expressing VEGF receptor (VEGFR-2/KDR), but did not express von Willebrand factor (VWF), VE-cadherin, P1H12 or TE-7. After 3 weeks of culture, the cells formed a monolayer with a typical EC morphology and expanded 11 +/- 5 times. The cells were further purified using Ulex europaeus agglutinin-1 (UEA-1)-fluorescein isothiocyanate (FITC) and anti-FITC microbeads, and expanded with VEGF for a further 3 weeks. All of the cells were CD45(-) and CD14(-), and expressed several endothelial markers (UEA-1, VWF, P1H12, CD105, E-selectin, VCAM-1 and VE-cadherin) and typical Weibel-Palade bodies. They had a high proliferative potential (up to a 2400-fold increase in cell number after 3 weeks of culture) and the capacity to modulate cell surface antigens upon stimulation with inflammatory cytokines. Purified ECs were also co-cultivated with CD34(+) cells, in parallel with a purified fibroblastic cell monolayer. CD34(+) cells (10 x 10(5)) gave rise to 17,951 +/- 2422 CFU-GM colonies when grown on endothelial cells, and to 12,928 +/- 4415 CFU-GM colonies on fibroblast monolayers. The ECs also supported erythroid blast-forming unit (BFU-E) colonies better. These results suggest that bone marrow CD133(+) progenitor cells can give rise to highly purified ECs, which have a high proliferative capacity, can be activated by inflammatory cytokines and are superior to fibroblasts in supporting haematopoiesis. Our data support the hypothesis that endothelial cell progenitors are present in adult bone marrow and may contribute to neo-angiogenesis.     

Bone marrow and tissue expression of gpIIb/IIIa, LFA-1, Mac-1 and gp150,95 glycoproteins

Monoclonal antibodies (MAbs) against platelet glycoprotein gpIIb/IIIa and the leucocyte adhesion molecules LFA-1, Mac-1, and gp 150,95 alpha chain (CD11a,b,c) and beta chain (CD18) have been tested in normal and leukaemic bone marrows, in different human tissues, and in a patient with leucocyte adhesion deficiency (LAD). The effect of these MAbs on platelet aggregation was also tested. GpIIb/IIIa showed widespread distribution, while reactivity of CD11/18 antibodies was limited to haematopoietic cells. Platelets and megakaryocytes were reactive with one CD11a (25.5.2), and with no CD11b/c or CD18 MAbs. GpIIb/IIIa was present on the platelets of the patient with LAD, whereas 25.5.2, (CD11a) bound to his platelets but not to his leucocytes. These data indicate that LFA-1, Mac-1, and gp150,95 are not present on human platelets, but they suggest the existence of crossreacting epitopes on gpIIb/IIIa, which is consistent with the hypothesis that these molecules belong to a supergene family of adhesion molecules.     

Identification of kinetochores and DNA synthesis in micronuclei induced by mitomycin C and colchicine in Chinese hamster ovary cells.

The presence of kinetochore and DNA synthesis in micronuclei (MN) induced in Chinese hamster ovary (CHO) cells by clastogenic and aneuploidogenic substances such as mitomycin C (MMC) and colchicine was determined by immunofluorescence technique using CREST antikinetochore antibodies and anti-bromodeoxyuridine (BrdUrd) antibodies. A cytofluorimetric analysis was also performed. Colchicine significantly increased micronucleated cells at least up to 96 h from the end of treatment. As expected, among colchicine-induced micronucleated cells the majority contained at least one CREST + MN. MMC induced a significant increase in micronucleated cells up to 120 h from the end of treatment and the great majority of MN lacked kinetochore fluorescence, indicating that MMC-induced MN were derived from acentric fragments. However, colchicine and MMC at 48 and 72 h from the end of treatment, induced a significant increase of CREST- and CREST + MN, respectively, suggesting an induction of clastogenicity by colchicine and aneuploidy by MMC. The clastogenic effect of colchicine after 48 h was also confirmed by the presence of chromatid fragments in metaphase cells. A cytofluorimetric analysis indicated that, as expected, colchicine and MMC interfere with the G2/M and S phases, respectively; however, a slight interference of colchicine with the S phase was also observed. DNA synthesis was present in MN and it was in most cases synchronous with synthesis in the main nucleus. The frequency of cells with MN in S phase observed in untreated or MMC-treated cells is in agreement with the proportion of cells without MN showing DNA synthesis. On the contrary, the frequency of cells with MN in S phase observed in colchicine-treated cells was significantly lower than that observed in control and MMC-treated cells.     

Inter- and intra-specific scaling of articular surface areas in the hominoid talus

The morphology of postcranial articular surfaces is expected to reflect their weight-bearing properties, as well as the stability and mobility of the articulations to which they contribute. Previous studies have mainly confirmed earlier predictions of isometric scaling between articular surface areas and body mass; the exception to this is 'male-type', convex articular surface areas, which may scale allometrically due to differences in locomotor strategies within the analysed samples. In the present study, we used new surface scanning technology to quantify more accurately articular surface areas and to test those predictions within the talus of hominoid primates, including modern humans. Our results, contrary to predictions, suggest that there are no generalised rules of articular scaling within the talus of hominoids. Instead, we suggest that articular scaling patterns are highly context-specific, depending on the role of each articulation during locomotion, as well as taxon- and sex-specific differences in locomotion and ontogenetic growth trajectories within any given sample. While this may prove problematic for inferring body mass based on articular surface area, it also offers new opportunities of gaining substantial insights into the locomotor patterns of extinct species.     

Dermatitis herpetiformis: pathophysiology,clinical presentation, diagnosis and treatment

Researches on DH have shown that it is not just a bullous skin disease, but a cutaneous-intestinal disorder caused by hypersensitivity to gluten. Exposure to gluten is the starting point of an inflammatory cascade capable of forming autoantibodies that are brought to the skin, where they are deposited, culminating in the formation of skin lesions. These lesions are vesico-bullous, pruritic, and localized especially on elbows, knees and buttocks, although atypical presentations can occur. Immunofluorescence of perilesional area is considered the gold standard for diagnosis, but serological tests help in cases where it is negative. Patients who follow glutenfree diets have better control of symptoms on the skin and intestine, as well as lower risks of progression to lymphoma. Dapsone remains the main drug for treatment, but it requires monitoring of possible side effects, some potentially lethal.