In vivo activation of the human δ-globin gene: the therapeutic potential in ß-thalassemic mice.

ß-thalassemia and sickle cell disease are widespread fatal genetic diseases. None of the existing clinical treatments provides a solution for all patients. Two main strategies for treatment are currently being investigated: (i) gene transfer of a normal ß-globin gene; (ii) reactivation of the endogenous γ-globin gene. To date, neither approach has led to a satisfactory, commonly accepted standard of care. The δ-globin gene produces the δ-globin of hemoglobin A2. Although expressed at a low level, hemoglobin A2 is fully functional and could be a valid substitute of hemoglobin A in ß-thalassemia, as well as an anti-sickling agent in sickle cell disease. Previous in vitro results suggested the feasibility of transcriptional activation of the human δ-globin gene promoter by inserting a Kruppel-like factor 1 binding site. We evaluated the activation of the Kruppel-like factor 1 containing δ-globin gene in vivo in transgenic mice. To evaluate the therapeutic potential we crossed the transgenic mice carrying a single copy activated δ-globin gene with a mouse model of ß-thalassemia intermedia. We show that the human δ-globin gene can be activated in vivo in a stage- and tissue-specific fashion simply by the insertion of a Kruppel-like factor 1 binding site into the promoter. In addition the activated δ-globin gene gives rise to a robust increase of the hemoglobin level in ß-thalassemic mice, effectively improving the thalassemia phenotype. These results demonstrate, for the first time, the therapeutic potential of the δ-globin gene for treating severe hemoglobin disorders which could lead to novel approaches, not involving gene addition or reactivation, to the cure of ß-hemoglobinopathies.

Differentiation of single cell derived human mesenchymal stem cells into cells with a neuronal phenotype: RNA and microRNA expression profile.

The adult bone marrow contains a subset of non-haematopoietic cells referred to as bone marrow mesenchymal stem cells (BMSCs). Mesenchymal stem cells (MSCs) have attracted immense research interest in the field of regenerative medicine due to their ability to be cultured for successive passages and multi-lineage differentiation. The molecular mechanisms governing the self-renewal and differentiation of MSCs remain largely unknown. In a previous paper we demonstrated the ability to induce human clonal MSCs to differentiate into cells with a neuronal phenotype (DMSCs). In the present study we evaluated gene expression profiles by Sequential Analysis of Gene Expression (SAGE) and microRNA expression profiles before and after the neuronal differentiation process. Various tissue-specific genes were weakly expressed in MSCs, including those of non-mesodermal origin, suggesting multiple potential tissue-specific differentiation, as well as stemness markers. Expression of OCT4, KLF4 and c-Myc cell reprogramming factors, which are modulated during the differentiation process, was also observed. Many peculiar nervous tissue genes were expressed at a high level in DMSCs, along with genes related to apoptosis. MicroRNA profiling and correlation with mRNA expression profiles allowed us to identify putative important genes and microRNAs involved in the differentiation of MSCs into neuronal-like cells. The profound difference in gene and microRNA expression patterns between MSCs and DMSCs indicates a real functional change during differentiation from MSCs to DMSCs.

HIV and Chagas Disease Coinfection, a Tractable Disease?

We present 2 patients born in Argentina who were newly diagnosed with advanced HIV disease and Chagas disease reactivation with central nervous system involvement. The patients received concurrent benznidazole treatment and antiretroviral therapy, showing good response. Improvement in morbidity and mortality due to early treatment makes this treatment appropriate for coinfected patients.

The value of some Corsican sub-populations for genetic association studies.

BACKGROUND: Genetic isolates with a history of a small founder population, long-lasting isolation and population bottlenecks represent exceptional resources in the identification of disease genes. In these populations the disease allele reveals Linkage Disequilibrium (LD) with markers over significant genetic intervals, therefore facilitating disease locus identification. In a previous study we examined the LD extension on the Xq13 region in three Corsican sub-populations from the inner mountainous region of the island. On the basis of those previous results we have proposed a multistep procedure to carry out studies aimed at the identification of genes involved in complex diseases in Corsica. A prerequisite to carry out the proposed multi-step procedure was the presence of different degrees of LD on the island and a common genetic derivation of the different Corsican sub-populations. In order to evaluate the existence of these conditions in the present paper we extended the analysis to the Corsican coastal populations. METHODS: Samples were analyzed using seven dinucleotide microsatellite markers on chromosome Xq13-21: DXS983, DXS986, DXS8092, DXS8082, DXS1225, DXS8037 and DXS995 spanning approximately 4.0 cM (13.3 Mb). We have also investigated the distribution of the DXS1225-DXS8082 haplotype which has been recently proposed as a good marker of population genetic history due to its low recombination rate. RESULTS: the results obtained indicate a decrease of LD on the island from the central mountainous toward the coastal sub-populations. In addition the analysis of the DXS1225-DXS8082 haplotype revealed: 1) the presence of a particular haplotype with high frequency; 2) the derivation from a common genetic pool of the sub-populations examined in the present study. CONCLUSION: These results indicate the Corsican sub-populations useful for the fine mapping of genes contributing to complex diseases.

Specific BIVA recognizes variation of body mass and body composition: Two related but different facets of nutritional status.

OBJECTIVE: The aim of this study was to demonstrate the different information provided by body mass index (BMI) in combination with specific bioelectrical impedance vector analysis (specific BIVA) in the measure of relative body fat. METHODS: Anthropometric and bioelectrical values and dual-energy x-ray absorpitometry measurements from a sample of 1590 US adults of both sexes were retrieved from the National Health and Nutrition Examination Survey 2003-2004. The sample distribution of the BMI of each sex was divided into deciles. Quartiles were calculated for percent fat mass (FM%) after stratifying by BMI deciles. Body composition and bioelectrical characteristics of groups below the first and above the third quartile were compared using analysis of variance and the Hotelling's T-square test. RESULTS: BMI and specific BIVA showed a different accuracy in detecting body composition variations: BMI showed similar values in groups represented by different FM percentages, whereas the bioelectrical differences were statistically significant. The mean impedance vectors corresponding to cases below the first FM% quartiles were shorter and located on the left side of the ellipses (the region of higher fat-free mass), whereas those above the third FM% quartiles were on the right and toward the upper pole (the region of higher FM%). CONCLUSIONS: Specific BIVA is a technique for the evaluation of body composition which can add relevant information regarding BMI.

Genetic isolates in Corsica (France): linkage disequilibrium extension analysis on the Xq13 region.

Genetic isolates with a history of a small founder population, long-lasting isolation and population bottlenecks represent exceptional resources in the identification of genes involved in the pathogenesis of multifactorial diseases. In these populations, the disease allele reveals linkage disequilibrium (LD) with markers over significant genetic intervals, therefore facilitating disease locus identification. This study has been designed to examine the background LD extension in some subpopulations of Corsica. Our interest in the island of Corsica is due to its geographical and genetic proximity to the other Mediterranean island of Sardinia. Sardinian isolates in which the extension of the background LD is particularly high have been recently identified and are now the object of studies aimed at the mapping of genes involved in complex diseases. Recent evidence has highlighted that the genetic proximity between the populations of Corsica and Sardinia is particularly true for the internal conservative populations. Given these considerations, Sardinia and Corsica may represent a unique system to carry out parallel association studies whose results could be validated by comparison. In the present study, we have analyzed the LD extension on the Xq13 genomic region in three subpopulations of Corsica: Corte, Niolo and Bozio, all located in the mountainous north-center of the island. Our results show a strong degree of LD over long distance for the population of Bozio and to a less extent for the population of Niolo. Their LD extent is comparable to or higher than that reported for other isolates.

beta-globin gene cluster haplotypes associated with beta-thalassemia on Corsica island.

In the Corsican population, the incidence of beta-thalassemia traits is reported to be 3.1%. We have investigated the 2 more important beta-thalassemia mutations present in the Corsican population: beta0-39 and beta+IVS1-110. Seven polymorphic sites in the beta-globin gene cluster were analyzed from a sample of 43 non-related beta-thalassemia heterozygotes and of 47 nonrelated healthy individuals, from Central Corsica (Corte). Among the 43 Corsican patients analyzed, the nonsense codon is predominant (88.40%), whereas the beta+IVS1-110 mutation, the most common of beta-thalassemia in the eastern part of the Mediterranean basin, is underrepresented (2.33%). The other individuals did not show positive for the two tested mutations (9.27%). The beta0-39 mutation in the studied population shows a strong association with haplotype II (18.7%) and a weaker association with haplotypes I (2.3%) and VII (2.1%). The strong association of the beta0-39 mutation with haplotype II was also found in Sardinia, suggesting that the mutation on the two islands have the same origin. In the present study all the data concerning frequencies of the mutations and of sequence haplotypes, support the hypothesis of a western Mediterranean origin of the beta0-39 mutation. For the first time, this paper analyzes the association of beta-globin gene cluster haplotypes with the 2 more frequent beta-thalassemia mutations in an isolated population in the centre of Corsica (Corte), which presents certain genetic peculiarities. However, the analysis of beta-haplotypes will be very useful for the genetic epidemiological study in this region.

Beta-globin gene cluster haplotypes in the Corsican and Sardinian populations.

The distribution of beta-globin cluster haplotypes has been studied in the populations of Corsica (France) and Sardinia (Italy). The analysis was carried out using five restriction fragment length polymorphism markers on chromosome 11 inside the beta-globin cluster using the restriction enzymes HincII and HindIII. The results show a remarkable heterogeneity within the two islands. However, the presence of rare haplotypes common to the most conservative areas (Nuoro and Corte) of the two islands is particularly interesting. These data support the hypothesis of a common origin of the populations of Sardinia and Corsica during the middle and upper Paleolithic periods and could be interpreted as a founder effect.