Characteristics and Properties of Mesenchymal Stem Cells Derived from Microfragmented Adipose Tissue

The subcutaneous adipose tissue provides a clear advantage over other mesenchymal stem cell sources due to the ease with which it can be accessed, as well as the ease of isolating the residing stem cells. Human adipose-derived stem cells (hADSCs), localized in the stromal–vascular portion, can be isolated ex vivo using a combination of washing steps and enzymatic digestion. In this study, we report that microfragmented human lipoaspirated adipose tissue is a better stem cell source compared to normal lipoaspirated tissue. The structural composition of microfragments is comparable to the original tissue. Differently, however, this procedure activates the expression of antigens, such as β-tubulin III. The hADSCs derived from microfragmented lipoaspirate tissue were systematically characterized for growth features, phenotype, and multipotent differentiation potential. They fulfill the definition of mesenchymal stem cells, although with a higher neural phenotype profile. These cells also express genes that constitute the core circuitry of self-renewal such as OCT4, SOX2, and NANOG, and neurogenic lineage genes such as NEUROD1, PAX6, and SOX3. Such findings suggest further studies by evaluating Microfrag-AT hADSC action in animal models of neurodegenerative conditions.

Third trimester amniotic fluid cells with the capacity to develop neural phenotypes and with heterogeneity among sub-populations

PURPOSE

Our aim was the search for new sources of cells potentially useful for central nervous system regenerative medicine. Extra-embryonic tissues are promising sources of pluripotent stem cells. Among these, human second-trimester amniotic fluid (AF) contains cell populations exhibiting self-renewal capacity, multipotency and the expression of embryonic cell markers.

METHODS

Here we report the properties of the easily available third-trimester AF cells (AFCs). Different cell types from 6 of 9 AF samples were separated, expanded, and characterized by assessing their morphological, proliferative, and differentiative properties.

RESULTS

All isolated cultures presented CD105, CD90 and CD73 mesenchymal markers, whereas they differed among themselves in CD117, CD146, CD31, NG2 and CD133 expression. Their doubling time and telomere length were conserved throughout many passages. Importantly, immunofluorescence and Real-time PCR showed that, during their proliferative state and differentiation, several cultures expressed neuronal and glial markers such as nestin, GFAP, β-tubulin III and neurofilament H indicating their potential attitude towards a neural fate. Indeed, these cells showed a rather poor capacity to differentiate in adipogenic and osteogenic lineages.

CONCLUSIONS

In this work we report that cells with neural differentiation capability can be isolated from third-trimester AF, such properties could be useful for neuro-regenerative purposes.

De novo balanced chromosome rearrangements in prenatal diagnosis

OBJECTIVE

We surveyed the datasheets of 29 laboratories concerning prenatal diagnosis of de novo apparently balanced chromosome rearrangements to assess the involvement of specific chromosomes, the breakpoints distribution and the impact on the pregnancy outcome.

METHOD

By means of a questionnaire, data on 269.371 analyses performed from 1983 to 2006 on amniotic fluid, chorionic villus and fetal blood samples were collected.

RESULTS

A total of 246 balanced anomalies were detected at frequencies of 72% for reciprocal translocations, 18% for Robertsonian translocations, 7% for inversions and 3% for complex chromosome rearrangements. The total frequencies of balanced rearrangements were 0.09%, 0.08% and 0.05% on amniotic fluid, chorionic villus and fetal blood samples.

CONCLUSION

A preferential involvement of chromosomes 22, 7, 21, 3, 9 and 11 and a less involvement of chromosomes X, 19, 12, 6 and 1 was observed. A nonrandom distribution of the breakpoints across chromosomes was noticed. Association in the location of recurrent breakpoints and fragile sites was observed for chromosomes 11, 7, 10 and 22, while it was not recorded for chromosome 3. The rate of pregnancy termination was about 20%, with frequencies decreasing from complex chromosomal rearrangements (33%), reciprocal translocations (24%) to inversions (11%) and Robertsonian translocations (3%).

Resveratrol inhibits cell growth in a human cholangiocarcinoma cell line

BACKGROUND/AIMS

Cholangiocarcinoma is a devastating tumour with a poor prognosis. An efficient therapy is unavailable in unoperable patients and new drugs are widely sought for and required. Resveratrol (RES) is a natural molecule with a reported anticancer effect, evaluated on different tumour cell lines. We tested the efficacy of RES on a cholangiocarcinoma cell line for the first time.

METHODS

We used the human SK-ChA-1 cell line, cultured in the classical two-dimensional model and in the three-dimensional spheroids. After RES exposure morphology, cell viability (colony-forming assay), lactate dehydrogenase (LDH), alkaline phosphatase (ALP) and cancer antigen (CA) 19-9 medium releases, cellular transglutaminase activity, karyotype and cell cycle were evaluated.

RESULTS

Resveratrol inhibited cell growth in both the cell culture systems used (from -15 to -80% vs untreated controls) and induced a 40-fold increase of LDH and ALP activities in the culture medium. Also, transglutaminase (TG) activity increased in the cell lysates, together with a cell cycle perturbation characterised by an accumulation in the G(1)/S phase. Karyotype and CA 19-9 expression were not influenced by the treatment.

CONCLUSIONS

The observed cytotoxic effect of RES on the human cholangiocarcinoma SK-ChA-1 cell line cultured two- and three-dimensionally suggests to further analyse its chemotherapic/chemopreventive possibilities for this kind of cancer.

Survivin expression in “low-risk” and “high-risk” myelodysplastic syndromes

Apoptosis has a crucial role in myelodysplastic syndromes (MDS), being responsible of the ineffective hematopoiesis characteristic of the disease. Apoptosis rate is elevated in "early phase" MDS, whereas it diminishes during disease progression to acute leukemia, consensually to the acquisition of independent growth features. Survivin is a member of the inhibitor of the apoptosis (IAP) family, with the bifunctional role of suppressing apoptosis while facilitating cell cycle progression. We investigated Survivin mRNA levels by real-time quantitative reverse transcriptase PCR analysis and Survivin protein expression by immunohistochemistry in 49 bone marrow (BM) aspirates and in 17 BM biopsies (BMB) from MDS patients. Survivin mRNA levels were higher in MDS than in control group (1.68 +/- 1.46 vs 0.25 +/- 0.22; p < 0.0001). MDS patients with low or INT1 International Scoring System for Evaluating Prognosis (IPSS) displayed higher levels of Survivin mRNA in comparison to INT2 or high IPSS (1.91 +/- 1.51 vs 0.88 +/- 0.95; p = 0.0058). Survivin protein immunoreactivity was evaluated as Survivin index S ((i)) and calculated according to the formula: S ((i)) = % of Survivin positive cells x BMB cellularity / 100. Survivin index was higher in the MDS group than in normal BM (p = 0.05). Moreover, in eight cases in which BM aspirates and trephine biopsy were available, we found a significant association between the level of Survivin mRNA and protein expression (p = 0.011). In conclusion, this study demonstrates increased levels of Survivin in MDS compared to normal controls. Moreover, higher levels of transcripts are related to "low-risk" MDS. Our results suggest an active role of Survivin in normal and in myelodysplastic hematopoiesis.

Diagnostic role and prognostic significance of a simplified immunophenotypic classification of mature B cell chronic lymphoid leukemias

We verified the diagnostic and prognostic role of a simplified immunophenotypic classification (IC) in a series of 258 patients (M/F: 1.4; median age: 64 years; median follow-up: 64 months; 75 deaths) with mature B cell lymphoid leukemias (MBC-LL) for whom no histopathological diagnosis was available because of minimal or no lymph node involvement. The IC was based on the reactivity of three pivotal immunophenotypic markers: CD5, CD23 and SIg intensity. On the basis of different expression patterns, we identified four diagnostic clusters (C) characterized by distinct clinico-biological features and different prognoses: C1 (149 patients) identified most classical B cell chronic lymphocytic leukemias (CLL-type cluster; SIg(dim)/CD5+/CD23+); C2, 38 patients whose clinico-hematological characteristics were intermediate between C1 and C3 (CLL-variant cluster; SIg(bright)/CD5+/CD23+/-or SIg(dim)/CD5-/-/CD23 indifferent); C3 (16 patients) most situations consistent with mantle cell lymphoma in leukemic phase (MCL-type cluster; SIg(bright)/CD5+/CD23-); and C4, 55 cases, most of whom were consistent with leukemic phase lymphoplasmacytic/splenic marginal zone lymphomas (LP/S-type cluster; SIg(bright)/CD5-/+/CD23 indifferent). At univariate survival analysis, prognosis worsened from C1 to C4, C2 and C3 (P = 0.0001), and this was maintained at multivariate analysis (P = 0.006), together with CD11c expression (P = 0.0043), age at diagnosis (cut-off 70 years; P = 0.0008) and platelet count (cut-off 140 x 10(9)/l; P = 0.0034). Besides recognising the two well-known situations of classic B-CLL and MCL, our IC identified situations with distinct prognostic and/or clinical behaviors.

Reduced intensity conditioning regimen followed by glycosylated G-CSF mobilized PBSCT in patients with solid tumors and malignant lymphomas

The aim of this pilot study was to exploit the graft-versus-tumor potential of allogeneic transplants while improving safety of the procedure. Twelve patients with advanced hematological malignancies and solid tumors underwent a low intensity conditioning regimen (fludarabine and cyclophosphamide) followed by an allogeneic peripheral blood stem cell transplantation. The median time to achieve an absolute neutrophil count of more than 0.5 x 10(9)/l and an untransfused platelet count of more than 20 x 10(9)/l was 15 and 14 days, respectively. The main extra-hematological toxicities were mucositis and infections. Acute graft-versus-host (GVHD) disease was experienced by 62% of evaluable patients (grade II/B or III/C 80%) responsive to steroids. Extensive chronic GVHD was observed in 62% of patients. Non-relapse transplant-related mortality by day +30 was observed in three patients (25%). Eight out of 12 patients were full donor chimeric by day +100. One patient showed a mixed chimerism at day +37 when he died from progressive disease. One patient was in complete remission (CR) before allogeneic transplantation, and after transplantation four patients achieved CR and four experienced progressive disease. Our study confirms that a low intensity conditioning regimen for allogeneic stem cell transplantation is feasible and effective in heavily pretreated patients.

New reciprocal translocation t(5;10)(q33;q22) associated with atypical chronic myeloid leukemia

We report a new chromosomal reciprocal translocation t(5;10)(q33;q22) in a 49-year-old man with atypical chronic myeloid leukemia (a-CML) and history of occupational exposure to petroleum products including benzene and other hydrocarbons. The t(5;10) (q33;q22) was found in 94% and 84% of metaphases in peripheral blood and bone marrow cells, respectively. Cytogenetic analysis of single colonies derived from granulocyte-macrophage (CFU-GM), and erythroid (BFU-E) hematopoietic progenitors showed that 88% and 40% of CFU-GM and BFU-E, respectively, had the t(5;10)(q33;q22). In contrast, peripheral blood T-lymphocytes, and cutaneous fibroblasts had normal 46,XY karyotype. Molecular analysis of the t(5;10)(q33;q22) translocation breakpoint is currently underway in order to identify genes located in this region which might provide insights into the pathogenesis of atypical myeloproliferative disorders.

Trisomic zygote rescue revealed by DNA polymorphism analysis in confined placental mosaicism

Uniparental disomy can be caused by different genetic mechanisms such as gamete complementation, chromosome duplication in monosomic zygote, or post-zygotic aneuploidy correction. This last mechanism is well documented in human reproduction and is related to placental mosaicism. In the case of a trisomic zygote which has originated by paternal or maternal non-disjunction at the first or second meiotic cell division, mosaicism will result from chromosome loss and restoration of a 'normalized' diploid fetal karyotype. In order to enrich the literature with new observations on this subject, we studied by DNA polymorphism analysis ten cases of confined placental mosaicism (CPM). The finding in placental DNA of three different alleles at polymorphic loci of chromosomes 13, 16, and 20 demonstrated the trisomic status of the zygote in three cases. On the basis of these results, we believe that systematic DNA polymorphism analysis could give useful additional information to improve knowledge on aneuploidy correction in human reproduction.

Localization of fos, jun, kit and SCF mRNA in human placenta throughout gestation using in situ RT-PCR

The expression pattern of c-fos, c-jun, c-kit and stem cell factor (SCF) has been investigated in developing human placenta using the highly sensitive technique of in situ reverse transcriptase-polymerase chain reaction (RT-PCR). Specific transcripts of all genes under study were observed in first-trimester placenta sections. c-fos, c-jun, c-kit and SCF transcripts were localized in cells of the villous stroma; fos, jun and kit-specific mRNAs were also found in endothelial cells; fos, kit and SCF mRNAs were detected in villous trophoblast cells. In mid-trimester and term placenta specimens only SCF transcripts were observed, restricted to trophoblast cells. The lack of c-fos transcripts in placenta from the second and third trimesters is a finding that contrasts with data from the literature obtained using extractive techniques. Parallel immunocytochemistry of placenta specimens from the three pregnancy stages under study revealed the fos protein only in first-trimester placenta, in agreement with the in situ RT-PCR findings. We conclude that the in situ RT-PCR technique is most suitable for gene expression studies because of its high level of sensitivity in correctly assigning the signal to specific cell types in complex tissues.

Prenatal diagnosis of 30 fetuses at risk for fragile X syndrome

The results of 30 prenatal diagnoses for fragile X syndrome are reported. Amniotic fluid cells were examined in 1 case, fetal blood in 4, and chorionic villi samples in the others. Of the 5 fetuses analyzed by cytogenetic methods, 1 had showed 4% of fraXq27.3 expression sites and the pregnancy was terminated. For 1 diagnosis, linkage analysis was used: the female fetus turned out to be normal. In 24 fetuses, the direct analysis of the mutation by StB12.3 probe was performed: 6 female and 3 male fetuses were found to carry a full mutation and 1 female fetus was found to carry a premutation. In 3 cases, the diagnoses were verified on fetal blood samples. Several tissues of 2 aborted male fetuses were analyzed for the fragile X mutation. The results are reported and discussed.

An improved procedure for in situ RTPCR

Direct in situ RTPCR has been successfully applied to paraffin-embedded human placental specimens. The expression of stem cell factor (SCF) mRNA visualized in cytotrophoblast and stromal cells is validated by the lack of any specific signal in parallel specimens where reverse transcription is omitted.

Genetic amniocentesis in biamniotic twin pregnancies by a single transabdominal insertion of the needle

We present a technique to aspirate amniotic fluid from both sacs in biamniotic twin pregnancies using a single abdominal insertion with a spinal needle. It was successful in 48 out of 55 cases of biamniotic twin pregnancies referred to our perinatal unit between 1985 and 1994. The single insertion technique was used when the inter-amniotic membrane was clearly evident and two separate free amniotic fluid pools could be reached by the operator with a single puncture. An adequate amount of amniotic fluid was sampled from both sacs to make a cytogenetic diagnosis in all cases. There were four fetuses with trisomy 21 in three twin pregnancies. In two cases, only one twin was affected whilst the co-twin was normal, so that a selective feticide was performed. No miscarriages due to genetic amniocentesis were reported. After 1990, all genetic amniocenteses in biamniotic twin pregnancies (except for one case due to late booking) were performed between 14 and 15 weeks of gestation and with all cases except one, it was possible to sample both twins by a single puncture. We suggest that early amniocentesis (14-15 weeks) by a single abdominal puncture could be a reliable and safe alternative to first-trimester chorionic villus sampling in twin pregnancies.

Chromosome 14 maternal uniparental disomy in the euploid cell line of a fetus with mosaic 46,XX/47,XX,+14 karyotype

We investigated the parental origin of the extra chromosome 14 and of the two chromosomes 14 of the euploid cell line, in a case of fetal mosaicism 46,XX/47,XX+14 diagnosed at amniocentesis. Molecular analysis of five polymorphic loci of the short tandem repeat type was performed. Markers D14S43 and D14S49 showed the presence of maternal uniparental disomy of chromosome 14 in the apparently normal cell line. The distribution of the markers analysed along the chromosome suggests maternal heterodisomy with a large isodisomic segment in the telomeric region, possibly caused by meiotic crossing-over.

A deletion map of the human Yq11 region: implications for the evolution of the Y chromosome and tentative mapping of a locus involved in spermatogenesis

A deletion map of Yq11 has been constructed by analyzing 23 individuals bearing structural abnormalities (isochromosomes, terminal deletions and X;Y, Y;X, or A;Y translocations) in the long arm of the Y chromosome. Twenty-two Yq-specific loci were detected using 14 DNA probes, ordered in 11 deletion intervals, and correlated with the cytogenetic map of the chromosome. The breakpoints of seven translocations involving Xp22 and Yq11 were mapped. The results obtained from at least five translocations suggest that these abnormal chromosomes may result from aberrant interchanges between X-Y homologous regions. The use of probes detecting Yq11 and Xp22.3 homologous sequences allowed us to compare the order of loci within these two chromosomal regions. The data suggest that at least three physically and temporary distinct rearrangements (pericentric inversion of pseudoautosomal sequences and/or X-Y transpositions and duplications) have occurred during evolution and account for the present organization of this region of the human Y chromosome. The correlation between the patient' phenotypes and the extent of their Yq11 deletions permits the tentative assignment of a locus involved in human spermatogenesis to a specific interval within Yq11.23.