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White adipocytes are plastic cells able to reversibly transdifferentiate into brown adipocytes and into epithelial glandular cells under physiologic stimuli in vivo. These plastic properties could be used in future for regenerative medicine, but are incompletely explored in their details. Here, we focused on plastic properties of human mature adipocytes (MA) combining gene expression profile through microarray analysis with morphologic data obtained by electron and time lapse microscopy. Primary MA showed the classic morphology and gene expression profile of functional mature adipocytes. Notably, despite their committed status, MA expressed high levels of reprogramming genes. MA from ceiling cultures underwent transdifferentiation toward fibroblast-like cells with a well-differentiated morphology and maintaining stem cell gene signatures. The main morphologic aspect of the transdifferentiation process was the secretion of large lipid droplets and the development of organelles necessary for exocrine secretion further supported the liposecretion process. Of note, electron microscope findings suggesting liposecretion phenomena were found also in explants of human fat and rarely in vivo in fat biopsies from obese patients. In conclusion, both MA and post-liposecretion adipocytes show a well-differentiated phenotype with stem cell properties in line with the extraordinary plasticity of adipocytes in vivo. J. Cell. Physiol. 232: 2887-2899, 2017. © 2016 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Abstract: Telomere dysfunction might generate genomic instability leading to the progression of myelodysplastic syndromes (MDS) into acute myeloid leukemia (AML). We investigated telomere length (TL), telomerase activity (TA) and hTERT, c-myc, mad1, and p53 expression in the bone marrow of patients with MDS (n =109), AML (n =47) and in controls (n =24). TL was lower in MDS patients than in controls (p <0.001) and higher in L-MDS (low, intermediate-1 IPSS, p <0.01) respect H-MDS (high, intermediate-2 IPSS, p <0.01) patients. Mad-1 expression was higher in MDS patients than in controls (p <0.01), c-myc expression was highest in AML and in H-MDS patients. Our results show that the telomere dynamics might be useful for stratifying patients according to a risk scoring system. [Copyright &y& Elsevier]

In vitro studies suggest that haploinsufficiency is involved in the pathogenesis of myelodysplastic syndromes (MDS). In patients with del5q cytogenetic abnormality, RPS-14 and microRNAs (miRNAs) play a major role. In a multicenter phase II single-arm trial with lenalidomide in anemic primary del5q MDS patients with low- or int-1 risk IPSS, biological changes from baseline were investigated. Gene expression profiling of selected genes was performed (TaqMan® Low Density Array Fluidic card, Applied Biosystems PRISM® 7900HT) and normalized against the expression of the 18S housekeeping gene from a pool of healthy subjects. Thirty-two patients were evaluated at baseline and after 3 and 6 months of treatment. RPS-14, miR-145, and miR-146 were downregulated at baseline and significantly increased during treatment. Nuclear factor kappa B, IL-6, interferon regulatory factor-1, IFNγ-R2, IL-2, and many genes in the apoptotic pathways (TNF, IL-1B, and IL-10) were upregulated at baseline and significantly downregulated during lenalidomide treatment, while forkhead box P3, FAS, IFNγ, IL-12A, and IL-12B were downregulated at baseline and progressively upregulated during treatment. The crucial role of aberrant immunological pathways and haploinsufficiency in the pathogenesis of del5q MDS is confirmed in the present patient setting. Our results indicate that lenalidomide may act through defined immunological pathways in this condition. [ABSTRACT FROM AUTHOR]

Mature adipocytes are generally considered terminally differentiated because they have lost their proliferative abilities. Here, we studied the gene expression and functional properties of mature adipocytes isolated from human omental and subcutaneous fat tissues. We also focused on dedifferentiated adipocytes in culture and their morphologies and functional changes with respect to mature adipocytes, stromal-vascular fraction (SVF)-derived mesenchymal stem cells (MSCs) and bone marrow (BM)-derived MSCs. Isolated mature adipocytes expressed stem cell and reprogramming genes. They replicated in culture after assuming a fibroblast-like shape and expanded similarly to SVF- and BM-derived MSCs. During the dedifferentiation process, mature adipocytes lost their lineage gene expression profile, assumed the typical mesenchymal morphology and immunophenotype, expressed stem cell genes and differentiated into multilineage cells. Moreover, during the dedifferentiation process, we showed changes in the epigenetic status of mature adipocytes, which led dedifferentiated adipocytes to display a similar DNA methylation condition to BM-derived MSCs. Like SVF- and BM-derived MSCs, dedifferentiated adipocytes were able to inhibit the proliferation of stimulated lymphocytes in coculture while mature adipocytes stimulated their growth. Furthermore, dedifferentiated adipocytes maintained the survival and complete differentiation characteristic of hematopoietic stem cells. This is the first study that in addition to characterizing isolated and dedifferentiated adipocytes also reports on the immunoregulatory and hematopoietic supporting functions of these cells. This structural and functional characterization might have clinical applications of both mature and dedifferentiated adipocytes in such fields, as regenerative medicine. S TEM C ELLS 2012;30:965-974 [ABSTRACT FROM AUTHOR]

Abstract: There are no reliable markers useful to predict the onset or the evolution of chronic graft-versus-host disease (cGVHD) after allogeneic hematopoietic stem cell transplantation (HSCT), although several candidate biomarkers have been identified from limited hypothesis-driven studies. In this study we evaluated 14 patients who received a reduced intensity conditioning HSCT. Seven patients had cGVHD, whereas 7 never developed cGVHD during the period of observation. The expression of 114 cytokines in immunoselected cell populations was explored by microarray analysis and 11 cytokines were selected for further evaluation by real-time PCR. Differential gene expression measurements showed a significant up-regulation for INFγ (interferon, gamma) in CD8+ and for TNFSF3 (tumor necrosis factor superfamily, member 3) and for TNFSF10 (tumor necrosis factor superfamily, member 10) in CD14+ cell population when comparing cGVHD with control samples. The expression levels were significantly decreased for TNFSF10 in CD8+ cell population and for TNFSF12 (tumor necrosis factor superfamily, member 12) and for PDGFβ (platelet-derived growth factor, beta) in CD4+. Our data seem to suggest that different immune populations can play a role in cGVHD pathogenesis and the early detection of gene expression profile in these patients could be useful in the monitoring of GVHD. We hypothesized that PDGFβ down-regulation could represent a negative feedback to compensate for enhanced expression of its receptor recently reported. [Copyright &y& Elsevier]

Background: Haploinsufficiency of the ribosomal protein S14 RPS14 gene, located in the common deleted region of chromosome 5q, is a potential causal factor of 5q− syndrome. Lenalidomide elicits high response rates and morphological improvements in myelodysplastic syndrome (MDS) patients with chromosome 5q deletion [del(5q)]. Methods: To further evaluate the role of RPS14, its transcription was tested in bone marrow cells from 17 patients with International Prognostic Scoring System defined Low- or Intermediate-1-risk MDS with del(5q) as a single or additional cytogenetic abnormality receiving treatment with lenalidomide. Results: After 12 wk of lenalidomide treatment, erythroid responses were observed in all cases with an increase in hemoglobin levels of 2.7 ± 2.5 g/dL (up to a mean 11.8 ± 1.9 g/dL; P = 0.001). Before treatment, RPS14 expression levels were under-expressed in 15 patients with respect to normal controls. After 12 wk of lenalidomide treatment, all patients had an erythroid response. There was a significant increase in median RPS14 expression from baseline 0.01 (IQR 0.05–0.31) to 12 wk 204.71-fold (2.86–446.32; P < 0.0001). Conclusions: These observations in the patient setting support the importance of RPS14 in the pathogenesis of MDS with del(5q). [ABSTRACT FROM AUTHOR]

Shwachman–Diamond syndrome (SDS) is a rare inherited bone marrow failure syndrome, resulting in neutropenia and a risk of myeloid neoplasia. A mutation in a ribosome maturation factor accounts for almost all of the cases. Lymphoid involvement in SDS has not been well characterized. We recently reported that lymphocyte subpopulations are reduced in SDS patients. We have also shown that the mTOR-STAT3 pathway is hyper-activated in SDS myeloid cell populations. Here we show that mTOR-STAT3 signaling is markedly upregulated in the lymphoid compartment of SDS patients. Furthermore, our data reveal elevated IL-6 levels in cellular supernatants obtained from lymphoblasts, bone marrow mononuclear and mesenchymal stromal cells, and plasma samples obtained from a cohort of 10 patients. Of note, everolimus-mediated inhibition of mTOR signaling is associated with basal state of phosphorylated STAT3. Finally, inhibition of mTOR-STAT3 pathway activation leads to normalization of IL-6 expression in SDS cells. Altogether, our data strengthen the hypothesis that SDS affects both lymphoid and myeloid blood compartment and suggest everolimus as a potential therapeutic agent to reduce excessive mTOR-STAT3 activation in SDS. [ABSTRACT FROM AUTHOR]

Adipocytes are a cell population largely located in the human bone marrow cavity. In this specific microenvironment where adipocytes can interact with a variety of different cells, the role of fat is mainly unknown. To our knowledge, this report is the first to characterize mature adipocytes isolated from human bone marrow (BM-A) molecularly and functionally to better understand their roles into the hematopoietic microenvironment. Healthy BM-A were isolated after collagenase digestion and filtration. We studied the morphology of BM-A, their gene expression and immunophenotypic profile and their functional ability in the hematopoietic microenvironment, comparing them with adipocytes derived from adipose tissue (AT-A). BM-A showed a unilocular lipid morphology similar to AT-A and did not lose their morphology in culture; they showed a comparable pattern of stem cell-surface antigens to AT-A. In line with these observations, molecular data showed that BM-A expressed some embryonic stem cells genes, such as Oct4, KLf4, c-myc, Gata4, Tbx1, and Sox17, whereas they did not express the stem cell markers Sox2 and Nanog. Moreover, BM-A had long telomeres that were similar to bone marrow mesenchymal stem cells. Notably, BM-A supported the survival and differentiation of hematopoietic stem cells in long-term cultures. These results showed that BM-A are stromal cells with a gene expression pattern that distinguished them from AT-A. BM-A showed stem cell properties through their hematopoietic supporting function, which was certainly linked to their role in the maintenance of the bone marrow microenvironment. Depending on specific demands, BM-A may acquire different functions based on their local environment. [ABSTRACT FROM AUTHOR]

Myelodysplastic syndromes and chronic myelomonocytic leukemia (CMML) are characterized by mutations in genes encoding epigenetic modifiers and aberrant DNA methylation. DNA methyltransferase inhibitors (DMTis) are used to treat these disorders, but response is highly variable, with few means to predict which patients will benefit. Here, we examined baseline differences in mutations, DNA methylation, and gene expression in 40 CMML patients who were responsive or resistant to decitabine (DAC) in order to develop a molecular means of predicting response at diagnosis. While somatic mutations did not differentiate responders from nonresponders, we identified 167 differentially methylated regions (DMRs) of DNA at baseline that distinguished responders from nonresponders using next-generation sequencing. These DMRs were primarily localized to nonpromoter regions and overlapped with distal regulatory enhancers. Usingthe methylation profiles, we developed an epigenetic classifier that accurately predicted DAC response at the time of diagnosis. Transcriptional analysis revealed differences in gene expression at diagnosis between responders and nonresponders. In responders, the upregulated genes included those that are associated with the cell cycle, potentially contributing to effective DAC incorporation. Treatment with CXCL4 and CXCL7, which were overexpressed in nonresponders, blocked DAC effects in isolated normal CD34+ and primary CMML cells, suggesting that their upregulation contributes to primary DAC resistance. [ABSTRACT FROM AUTHOR]