The insulin-like growth factor system in hematopoietic cells

The treatment of chronic anemia in heart failure: a global approach

Chronic anemia is an independent risk factor for mortality in patients with heart failure (HF). Restoring physiological hemoglobin (Hb) levels is essential to increase oxygen transport capacity to tissues and improve cell metabolism as well as physical and cardiac performance. Nutritional deficits and iron deficiency are the major causes of chronic anemia, but other etiologies include chronic kidney disease, inflammatory processes, and unexplained anemia. Hormonal therapy, including erythropoietin (EPO) and anabolic treatment in chronic anemia HF patients, may contribute to improving Hb levels and clinical outcomes. Although preliminary studies showed a beneficial effect of EPO therapy on cardiac efficiency and in HF, more recent studies have not confirmed this positive impact of EPO, alluding to its side effect profile. Physical exercise significantly increases Hb levels and the response of anemia to treatment. In malnourished patients and chronic inflammatory processes, low levels of anabolic hormones, such as testosterone and insulin-like growth factor-1, contribute to the development of chronic anemia. This paper aims to review the effect of nutrition, EPO, anabolic hormones, standard HF treatments, and exercise as regulatory mechanisms of chronic anemia and their cardiovascular consequences in patients with HF.

Interplay of IGF1R and estrogen signaling regulates hematopoietic stem and progenitor cells

Tissue stem cells often exhibit developmental stage-specific and sexually dimorphic properties, but the underlying mechanism remains largely elusive. By characterizing IGF1R signaling in hematopoietic cells, here we report that its disruption exerts sex-specific effects in adult hematopoietic stem and progenitor cells (HSPCs). Loss of IGF1R decreases the HSPC population in females but not in males, in part due to a reduction in HSPC proliferation induced by estrogen. In addition, the adult female microenvironment enhances engraftment of wild-type but not Igf1r-null HSPCs. In contrast, during gestation, when both female and male fetuses are exposed to placental estrogens, loss of IGF1R reduces the numbers of their fetal liver HSPCs regardless of sex. Collectively, these data support the interplay of IGF1R and estrogen pathways in HSPCs and suggest that the proliferation-promoting effect of estrogen on HSPCs is in part mediated via IGF1R signaling.

Anti-Gene IGF-I Vaccines in Cancer Gene Therapy: A Review of a Case of Glioblastoma

OBJECTIVE

Vaccines for the deadliest brain tumor - glioblastoma (GBM) - are generally based on targeting growth factors or their receptors, often using antibodies. The vaccines described in the review were prepared to suppress the principal cancer growth factor - IGF-I, using anti-gene approaches either of antisense (AS) or of triple helix (TH) type. Our objective was to increase the median survival of patients treated with AS and TH cell vaccines.

METHODOLOGY

The cells were transfected in vitro by both constructed IGF-I AS and IGF-I TH expression episomal vectors; part of these cells was co-cultured with plant phytochemicals, modulating IGF-I expression. Both AS and TH approaches completely suppressed IGF-I expression and induced MHC-1 / B7 immunogenicity related to the IGF-I receptor signal.

RESULTS

This immunogenicity proved to be stronger in IGF-I TH than in IGF-I AS-prepared cell vaccines, especially in TH / phytochemical cells. The AS and TH vaccines generated an important TCD8+ and TCD8+CD11b- immune response in treated GBM patients and increased the median survival of patients up to 17-18 months, particularly using TH vaccines; in some cases, 2- and 3-year survival was reported. These clinical results were compared with those obtained in therapies targeting other growth factors.

CONCLUSION

The anti-gene IGF-I vaccines continue to be applied in current GBM personalized medicine. Technical improvements in the preparation of AS and TH vaccines to increase MHC-1 and B7 immunogenicity have, in parallel, allowed to increase in the median survival of patients.

Maternal anemia and childhood cancer: a population-based case-control study in Denmark

BACKGROUND

Childhood cancer risk is associated with maternal health during pregnancy. Anemia in pregnancy is a common condition, especially in low-income countries, but a possible association between maternal anemia and childhood cancer has not been widely studied.

METHODS

We examined the relation in a population-based study in Denmark (N = 6420 cancer cases, 160,485 controls). Cases were taken from the Danish Cancer Registry, and controls were selected from national records. We obtained maternal anemia diagnoses from the National Patient and Medical Births registries. In a separate analysis within the years available (births 1995-2014), we examined cancer risks among mothers taking prescribed vitamin supplements, using data from the National Prescription Register. We estimated the risks of childhood cancer using conditional logistic regression.

RESULTS

The risks of neuroblastoma [odds ratio (OR= 1.83, 95% confidence interval (CI): 1.04, 3.22] and acute lymphoblastic leukemia (OR= 1.46, 95% CI 1.09, 1.97) were increased in children born to mothers with anemia in pregnancy. There was a two-fold increased risk for bone tumors (OR= 2.59, 95% CI: 1.42, 4.72), particularly osteosarcoma (OR= 3.54, 95% CI 1.60, 7.82). With regards to prescribed supplement use, mothers prescribed supplements for B12 and folate deficiency anemia (OR= 4.03, 95% CI 1.91, 8.50) had an increased risk for cancer in offspring.

CONCLUSION

Our results suggest that screening for anemia in pregnancy and vitamin supplementation may be an actionable strategy to prevent some cases of childhood cancer.

Induced Pluripotent Stem Cells to Model Juvenile Myelomonocytic Leukemia: New Perspectives for Preclinical Research

Juvenile myelomonocytic leukemia (JMML) is a malignant myeloproliferative disorder arising in infants and young children. The origin of this neoplasm is attributed to an early deregulation of the Ras signaling pathway in multipotent hematopoietic stem/progenitor cells. Since JMML is notoriously refractory to conventional cytostatic therapy, allogeneic hematopoietic stem cell transplantation remains the mainstay of curative therapy for most cases. However, alternative therapeutic approaches with small epigenetic molecules have recently entered the stage and show surprising efficacy at least in specific subsets of patients. Hence, the establishment of preclinical models to test novel agents is a priority. Induced pluripotent stem cells (IPSCs) offer an opportunity to imitate JMML ex vivo, after attempts to generate immortalized cell lines from primary JMML material have largely failed in the past. Several research groups have previously generated patient-derived JMML IPSCs and successfully differentiated these into myeloid cells with extensive phenotypic similarities to primary JMML cells. With infinite self-renewal and the capability to differentiate into multiple cell types, JMML IPSCs are a promising resource to advance the development of treatment modalities targeting specific vulnerabilities. This review discusses current reprogramming techniques for JMML stem/progenitor cells, related clinical applications, and the challenges involved.

Epigenetic Effects of Benzene in Hematologic Neoplasms: The Altered Gene Expression

Simple Summary

Benzene is produced by diverse petroleum transformation processes and it is widely employed in industry despite its oncogenic effects. In fact, occupational exposure to benzene may cause hematopoietic malignancy. The leukemogenic action of benzene is particularly complex. Possible processes of onset of hematological malignancies have been recognized as a genotoxic action and the provocation of immunosuppression. However, benzene can induce modifications that do not involve alterations in the DNA sequence, the so-called epigenetics changes. Acquired epigenetic modification may also induce leukemogenesis, as benzene may alter nuclear receptors, and cause changes at the protein level, thereby modifying the function of regulatory proteins, including oncoproteins and tumor suppressor proteins.

Abstract

Benzene carcinogenic ability has been reported, and chronic exposure to benzene can be one of the risk elements for solid cancers and hematological neoplasms. Benzene is acknowledged as a myelotoxin, and it is able to augment the risk for the onset of acute myeloid leukemia, myelodysplastic syndromes, aplastic anemia, and lymphomas. Possible mechanisms of benzene initiation of hematological tumors have been identified, as a genotoxic effect, an action on oxidative stress and inflammation and the provocation of immunosuppression. However, it is becoming evident that genetic alterations and the other causes are insufficient to fully justify several phenomena that influence the onset of hematologic malignancies. Acquired epigenetic alterations may participate with benzene leukemogenesis, as benzene may affect nuclear receptors, and provoke post-translational alterations at the protein level, thereby touching the function of regulatory proteins, comprising oncoproteins and tumor suppressor proteins. DNA hypomethylation correlates with stimulation of oncogenes, while the hypermethylation of CpG islands in promoter regions of specific tumor suppressor genes inhibits their transcription and stimulates the onset of tumors. The discovery of the systems of epigenetic induction of benzene-caused hematological tumors has allowed the possibility to operate with pharmacological interventions able of stopping or overturning the negative effects of benzene.

Pleiotropic Effect of Hormone Insulin-Like Growth Factor-I in Immune Response and Pathogenesis in Leishmaniases

Leishmaniases are diseases caused by several Leishmania species, and many factors contribute to the development of the infection. Because the adaptive immune response does not fully explain the outcome of Leishmania infection and considering that the initial events are crucial in the establishment of the infection, we investigated one of the growth factors, the insulin-like growth factor-I (IGF-I), found in circulation and produced by different cells including macrophages and present in the skin where the parasite is inoculated. Here, we review the role of IGF-I in leishmaniasis experimental models and human patients. IGF-I induces the growth of different Leishmania species in vitro and alters the disease outcome increasing the parasite load and lesion size, especially in L. major- and L. amazonensis-infected mouse leishmaniasis. IGF-I affects the parasite interacting with the IGF-I receptor present on Leishmania. During Leishmania-macrophage interaction, IGF-I acts on the arginine metabolic pathway, resulting in polyamine production both in macrophages and Leishmania. IGF-I and cytokines interact with reciprocal influences on their expression. IL-4 is a hallmark of susceptibility to L. major in murine leishmaniasis, but we observed that IGF-I operates astoundingly as an effector element of the IL-4. Approaching human leishmaniasis, patients with mucosal, disseminated, and visceral diseases presented surprisingly low IGF-I serum levels, suggesting diverse effects than parasite growth. We observed that low IGF-I levels might contribute to the inflammatory response persistence and delayed lesion healing in human cutaneous leishmaniasis and the anemia development in visceral leishmaniasis. We must highlight the complexity of infection revealed depending on the Leishmania species and the parasite's developmental stages. Because IGF-I exerts pleiotropic effects on the biology of interaction and disease pathogenesis, IGF-I turns up as an attractive tool to explore biological and pathogenic processes underlying infection development. IGF-I pleiotropic effects open further the possibility of approaching IGF-I as a therapeutical target.

IGF-1 infusion to fetal sheep increases organ growth but not by stimulating nutrient transfer to the fetus

Insulin-like growth factor-1 (IGF-1) is an important fetal growth factor. However, the role of fetal IGF-1 in increasing placental blood flow, nutrient transfer, and nutrient availability to support fetal growth and protein accretion is not well understood. Catheterized fetuses from late gestation pregnant sheep received an intravenous infusion of LR3 IGF-1 (LR3 IGF-1; n = 8) or saline (SAL; n = 8) for 1 wk. Sheep then underwent a metabolic study to measure uterine and umbilical blood flow, nutrient uptake rates, and fetal protein kinetic rates. By the end of the infusion, fetal weights were not statistically different between groups (SAL: 3.260 ± 0.211 kg, LR3 IGF-1: 3.682 ± 0.183; P = 0.15). Fetal heart, adrenal gland, and spleen weights were higher (P < 0.05), and insulin was lower in LR3 IGF-1 (P < 0.05). Uterine and umbilical blood flow and umbilical uptake rates of glucose, lactate, and oxygen were similar between groups. Umbilical amino acid uptake rates were lower in LR3 IGF-1 (P < 0.05) as were fetal concentrations of multiple amino acids. Fetal protein kinetic rates were similar. LR3 IGF-1 skeletal muscle had higher myoblast proliferation (P < 0.05). In summary, LR3 IGF-1 infusion for 1 wk into late gestation fetal sheep increased the weight of some fetal organs. However, because umbilical amino acid uptake rates and fetal plasma amino acid concentrations were lower in the LR3 IGF-1 group, we speculate that animals treated with LR3 IGF-1 can efficiently utilize available nutrients to support organ-specific growth in the fetus rather than by stimulating placental blood flow or nutrient transfer to the fetus.NEW & NOTEWORTHY After a 1-wk infusion of LR3 IGF-1, late gestation fetal sheep had lower umbilical uptake rates of amino acids, lower fetal arterial amino acid and insulin concentrations, and lower fetal oxygen content; however, LR-3 IGF-1-treated fetuses were still able to effectively utilize the available nutrients and oxygen to support organ growth and myoblast proliferation.

IGF-I deficiency and enhanced insulin sensitivity due to a mutated growth hormone receptor gene in humans

Human size is achieved by the coordinated expression of many genes. From conception to adulthood, a given genomic endowment is modified by highly variable environmental circumstances. During each stage of a person's life, distinct nutritional and hormonal influences continuously shape growing physical features until mature characteristics are attained. Underlying processes depend on precise provision of substrates and energy extracted by insulin action from nutrients, which allows cell proliferation, differentiation, and survival, under the concerted actions of growth hormone and insulin-like growth factor-I (IGF-I). It should be noted that growth and metabolic signaling pathways are interdependent and superimposed at multiple levels. Attainment of a fully developed human phenotype should be considered as a harmonious increment in body size rather than a simple increase in height. From this perspective we herein analyze adult features of individuals with an inactive growth hormone receptor, who consequently have severely diminished concentrations of serum insulin and endocrine IGF-I.

Extracellular vesicles from human iPSCs enhance reconstitution capacity of cord blood-derived hematopoietic stem and progenitor cells

Cord blood (CB) represents a source of hematopoietic stem and progenitor cells (CB-HSPCs) for bone marrow (BM) reconstitution, but clinical CB application is limited in adult patients due to the insufficient number of CB-HSCPCs and the lack of effective ex vivo approaches to increase CB-HSPC functionality. Since human-induced pluripotent stem cells (hiPSCs) have been indicated as donor cells for bioactive extracellular vesicles (EVs) modulating properties of other cells, we are the first to employ hiPSC-derived EVs (hiPSC-EVs) to enhance the hematopoietic potential of CB-derived CD45^dimLin^-CD34⁺ cell fraction enriched in CB-HSPCs. We demonstrated that hiPSC-EVs improved functional properties of CB-HSPCs critical for their hematopoietic capacity including metabolic, hematopoietic and clonogenic potential as well as survival, chemotactic response to stromal cell-derived factor 1 and adhesion to the model components of hematopoietic niche in vitro. Moreover, hiPSC-EVs enhanced homing and engraftment of CB-HSPCs in vivo. This phenomenon might be related to activation of signaling pathways in CB-HSPCs following hiPSC-EV treatment, as shown on both gene expression and the protein kinases activity levels. In conclusion, hiPSC-EVs might be used as ex vivo modulators of CB-HSPCs capacity to enhance their functional properties and augment future practical applications of CB-derived cells in BM reconstitution.

The intra-individual stability of GH biomarkers IGF-I and P-III-NP in relation to GHRH administration, menstrual cycle, and hematological parameters

The intra-individual stability of growth hormone (GH) biomarkers IGF-I, P-III-NP, calculated GH-2000 score in relation to growth hormone-releasing hormone (GHRH) (Somatorelin) administration, menstrual cycle, and hematological parameters were investigated in four men and eight women, respectively. Moreover, the hematological parameters hemoglobin (Hb) and percentage of reticulocyte (RET%) were statistically analyzed in relation to the GH biomarker parameters for the GHRH administration study and the menstrual cycle study. Longitudinal monitoring of IGF-I and/or GH-2000 score proved to be a viable approach to detect the GHRH intake in men, as all four participants show values above individually calculated thresholds (calculated as mean ± 3SD from three baseline samples). The intra-individual variation for IGF-I, P-III-NP, and calculated GH-2000 score in women, over two consecutive menstrual cycles, was investigated and established to be higher (coefficients variations [CVs] between 12% and 186%) than in men (CVs between 3% and 12%). The GHRH administration did not influence the hematological parameters. A strong positive correlation between Hb and IGF-I (Rs = 0.73, p < 0.0001) and a borderline weak correlation between RET% and IGF-I (Rs = 0.28, p = 0.054) were noticed in the women. No correlation for the P-III-NP and the hematological parameters was seen for the females in the menstrual cycle study. The results fortify previous studies that longitudinal monitoring of IGF-I and/or GH-2000 score may be a promising method to detect doping with GH and GH stimulating agents in men, whereas the large intra-individual variation noted in women indicates that longitudinal monitoring of these biomarker may be harder to evaluate in women.

Association between Insulin-Like Growth Factor-I Levels and the Disease Progression and Anemia in Visceral Leishmaniasis

We analyzed the association between insulin-like growth factor-I (IGF-I) and the pathogenesis of anemia during active visceral leishmaniasis (VL). Serum levels of IGF-I, IGF-binding protein 3 (IGFBP3), and cytokines were measured in samples from individuals with active VL and cured VL, asymptomatic Leishmania-infected, and noninfected individuals. Then, we extended our analysis to VL dogs to evaluate hematimetric parameters, bone marrow alterations, and cytokine and IGF-I expression. We identified a positive correlation between lower IGF-I and IGFBP3 levels in active VL patients and lower hemoglobin levels. In infected dogs, there was a positive correlation between lower IGF-I expression in the bone marrow and lower peripheral blood hematocrit and hemoglobin levels. There was no correlation between decreased IGF-I level/expression and any measured cytokine serum levels in either host. The data suggest that low IGF-I expression is associated with pathogenesis of anemia in active VL, primarily in severe cases, by mechanisms other than alterations in cytokine production.

Genome-wide association analysis identifies SNPs predictive of in vitro leukemic cell sensitivity to cytarabine in pediatric AML

Cytarabine has been an integral part of acute myeloid leukemia (AML) chemotherapy for over four decades. However, development of resistance and high rates of relapse is a significant impediment in successfully treating AML. We performed a genome-wide association analysis (GWAS) and identified 113 (83 after adjusting for Linkage Disequilibrium) SNPs associated with in vitro cytarabine chemosensitivity of diagnostic leukemic cells from a cohort of 50 pediatric AML patients (p<10^-4). Further evaluation of diagnostic leukemic cell gene-expression identified 19 SNP-gene pairs with a concordant triad of associations: i)SNP genotype with cytarabine sensitivity (p<0.0001), ii) gene-expression with cytarabine sensitivity (p<0.05), and iii) genotype with gene-expression (p<0.1). Two genes from SNP-gene pairs, rs1376041-GPR56 and rs75400242-IGF1R, were functionally validated by siRNA knockdown in AML cell lines. Consistent with association of rs1376041 and gene-expression in AML patients siRNA mediated knock-down of GPR56 increased cytarabine sensitivity of AML cell lines. Similarly for IGF1R, knockdown increased the cytarabine sensitivity of AML cell lines consistent with results in AML patients. Given both IGF1R and GPR56 are promising drug-targets in AML, our results on SNPs driving the expression/function of these genes will not only enhance our understanding of cytarabine resistance but also hold promise in personalizing AML for targeted therapies.

Gamma-Tocotrienol Modulates Radiation-Induced MicroRNA Expression in Mouse Spleen

Ionizing radiation causes depletion of hematopoietic cells and enhances the risk of developing secondary hematopoietic malignancies. Vitamin E analog gamma-tocotrienol (GT3), which has anticancer properties, promotes postirradiation hematopoietic cell recovery by enhancing spleen colony-forming capacity, and provides protection against radiation-induced lethality in mice. However, the underlying molecular mechanism involved in GT3-mediated postirradiation survival is not clearly understood. Recent studies have shown that natural dietary products including vitamin E provide a benefit to biological systems by modulating microRNA (miR) expression. In this study, we show that GT3 differentially modulates the miR footprint in the spleen of irradiated mice compared to controls at early times (day 1), as well as later times (day 4 and 15) after total-body irradiation. We observed that miR expression was altered in a dose- and time-dependent manner in GT3-pretreated spleen tissues from total-body irradiated mice. GT3 appeared to affect the expression of a number of radiation-modulated miRs known to be involved in hematopoiesis and lymphogenesis. Moreover, GT3 pretreatment also suppressed the upregulation of radiation-induced p53, suggesting the function of GT3 in the prevention of radiation-induced damage to the spleen. In addition, we have shown that GT3 significantly reduced serum levels of Flt3L, a biomarker of radiation-induced bone marrow aplasia. Further in silico analyses of the effect of GT3 implied the association of p38 MAPK, ERK and insulin signaling pathways. Our study provides initial insight into the mechanism by which GT3 mediates protection of spleen after total-body irradiation.

The Role of the Multiple Hormonal Dysregulation in the Onset of "Anemia of Aging": Focus on Testosterone, IGF-1, and Thyroid Hormones

Anemia is a multifactorial condition whose prevalence increases in both sexes after the fifth decade of life. It is a highly represented phenomenon in older adults and in one-third of cases is "unexplained." Ageing process is also characterized by a "multiple hormonal dysregulation" with disruption in gonadal, adrenal, and somatotropic axes. Experimental studies suggest that anabolic hormones such as testosterone, IGF-1, and thyroid hormones are able to increase erythroid mass, erythropoietin synthesis, and iron bioavailability, underlining a potential role of multiple hormonal changes in the anemia of aging. Epidemiological data more consistently support an association between lower testosterone and anemia in adult-older individuals. Low IGF-1 has been especially associated with anemia in the pediatric population and in a wide range of disorders. There is also evidence of an association between thyroid hormones and abnormalities in hematological parameters under overt thyroid and euthyroid conditions, with limited data on subclinical statuses. Although RCTs have shown beneficial effects, stronger for testosterone and the GH-IGF-1 axis and less evident for thyroid hormones, in improving different hematological parameters, there is no clear evidence for the usefulness of hormonal treatment in improving anemia in older subjects. Thus, more clinical and research efforts are needed to investigate the hormonal contribution to anemia in the older individuals.

Insulin-like growth factor 1 receptor is a prognostic factor in classical Hodgkin lymphoma

The interaction between the tumor cells in classical Hodgkin lymphoma (cHL) and the microenvironment includes aberrant activity of receptor tyrosine kinases. In this study we evaluated the expression, functionality and prognostic significance of Insulin-like growth factor-1 receptor (IGF-1R) in cHL. IGF-1R was overexpressed in 55% (44/80) of cHL patients. Phosphorylated IGF-1R was detectable in a minority of the IGF-1R positive tumor cells. The overall survival (OS, 98%) and 5-year progression-free survival (PFS, 93%) was significantly higher in IGF-1R positive cHL patients compared to IGF-1R negative patients (OS 83%, p = .029 and PFS 77%, p = .047, respectively). Three cHL cell lines showed expression of IGF-1R, with strong staining especially in the mitotic cells and expression of IGF-1. IGF-1 treatment had a prominent effect on the cell growth of L428 and L1236 cells and resulted in an increased phosphorylation of IGF1R, Akt and ERK. Inhibition of IGF-1R with cyclolignan picropodophyllin (PPP) decreased cell growth and induced a G2/M cell cycle arrest in all three cell lines. Moreover, a decrease in pCcd2 and an increase in CyclinB1 levels were observed which is consistent with the G2/M cell cycle arrest. In conclusion, IGF-1R expression in HRS cells predicts a favorable outcome, despite the oncogenic effect of IGF-1R in cHL cell lines.

Whole genome expression profiling and screening for differentially expressed cytokine genes in human bone marrow endothelial cells treated with humoral inhibitors in liver cirrhosis

Bone marrow endothelial cells (BMECs) are important components of the hematopoietic microenvironment in bone marrow, and they can secrete several types of cytokines to regulate the functions of hematopoietic stem/progenitor cells. To date, it is unknown whether BMECs undergo functional changes and lead to hematopoietic abnormalities in cases of liver cirrhosis (LC). In the present study, whole genome microarray analysis was carried out to detect differentially expressed genes in human BMECs treated for 48 h with medium supplemented with 20% pooled sera from 26 patients with LC or 10 healthy volunteers as the control group. A total of 1,106 upregulated genes and 766 downregulated genes were identified. In Gene Ontology analysis, the most significant categories of genes were revealed. A large number of the upregulated genes were involved in processes, such as cell-cell adhesion, apoptosis and cellular response to stimuli and the downregulated genes were involved in the negative regulation of secretion, angiogenesis, blood vessel development and cell growth. Pathway analysis revealed that the upregulated genes were either cell adhesion molecules or parts of the apoptotic signaling pathway and the downregulated genes were involved in the Wnt signaling pathway and MAPK signaling pathway. These were the pathways with the highest enrichment scores. The results of apoptosis assays revealed that the humoral inhibitors in the sera of patients with LC induced the apoptosis of BMECs, which confirmed the accuracy of bioinformatic analysis. Moreover, we screened and verified 21 differentially expressed cytokine genes [transforming growth factor (TGF)B1, tumor necrosis factor (TNF)B, TNF receptor superfamily, member 11b (TNFRSF11B), TNF (ligand) superfamily, member 13b (TNFSF13B), interleukin (IL)1A, IL6, IL11, IL17C, IL24, family with sequence similarity 3, member B (FAM3B), Fas ligand (FASLG), matrix metallopeptidase (MMP)3, MMP15, vitronectin (VTN), insulin-like growth factor 1 (IGF1), fibroblast growth factor 22 (FGF22), slit homolog 2 (Drosophila) (SLIT2), thrombospondin (THBS)2, THBS3, chemokine (C-C motif) ligand 28 (CCL28) and macrophage stimulating 1 (MST1)] from 97 cytokine genes in BMECs treated with serum from patients with LC. The results from our study demonstrate that the humoral inhibitors in the sera of patients with LC induce the dysfunction and abnormal cytokine secretion by BMECs, which may be a novel mechanism responsible for hematological abnormalities in patients with LC.

Chronically inadequate sleep results in abnormal bone formation and abnormal bone marrow in rats

Insufficient sleep over long durations of the lifespan is believed to adversely affect proper development and healthful aging, although how this might become manifested is unknown. In the present study, rats were repeatedly sleep-restricted during 72 days to permit maladaptations to evolve, thereby permitting study. Densitometric and histomorphometric analyses were performed on harvested bone. In sleep-restricted rats, bone lined by osteoid was reduced 45-fold and osteoid thickness was decreased, compared with controls. This corresponded to a decrease in osteoblast number and activity. The percentage of bone lined by osteoclasts did not differ from that of controls. Plasma concentrations of an osteoclast marker (TRACP 5b) were increased in sleep-restricted rats, indicating increased bone resorption. The low amount of new bone formation without a reduction in bone resorption is diagnostic of osteopenia. Bone mineral density was decreased in femurs from sleep-restricted rats compared with controls, indicating osteoporosis. Red marrow in sleep-restricted rats contained only 37% of the fat and more than twice the number of megakaryocytes compared with that of the control rats. These findings in marrow suggest changed plasticity and increased hematopoiesis. Plasma concentrations of insulin-like growth factor-1, a known, major mediator of osteoblast differentiation and the proliferation of progenitor cells, was decreased by 30% in sleep-restricted rats. Taken together, these findings suggest that chronically inadequate sleep affects bone metabolism and bone marrow composition in ways that have implications for development, aging, bone healing and repair, and blood cell differentiation.

Role of insulin-like growth factor-1 (IGF-1) pathway in the pathogenesis of Graves' orbitopathy

The etiology of Graves' orbitopathy (GO) remains enigmatic and thus controversy surrounds its pathogenesis. The role of the thyroid stimulating hormone receptor (TSHR) and activating antibodies directed against it in the hyperthyroidism of Graves' disease (GD) is firmly established. Less well elucidated is what part the TSHR pathway might play in the development of GO. Also uncertain is the participation of other cell surface receptors in the disease. Elevated levels of insulin-like growth factor-1 receptor (IGF-1R) have been found in orbital fibroblasts as well as B and T cells from patients with GD. These abnormal patterns of IGF-1R display are also found in rheumatoid arthritis and carry functional consequences. In addition, activating IgGs capable of displacing IGF-1 from IGF-1R have also been detected in patients with these diseases. IGF-1R forms a complex with TSHR which is necessary for at least some of the non-canonical signaling observed following TSHR activation. Functional TSHR and IGF-1R have also been found on fibrocytes, CD34⁺ bone marrow-derived cells from the monocyte lineage. Levels of TSHR on fibrocytes greatly exceed those found on orbital fibroblasts. When ligated by TSH or M22, a TSHR-activating monoclonal antibody, fibrocytes produce extremely high levels of several cytokines and chemokines. Moreover, fibrocytes infiltrate both the orbit and thyroid in GD. In sum, based on current evidence, IGF-1R and TSHR can be thought of as "partners in crime". Involvement of the former probably transcends disease boundaries, while TSHR may not.

Involvement of the IGF system in fetal growth and childhood cancer: an overview of potential mechanisms

Fetal growth is determined by a complex interplay of genetic, nutritional, environmental, and hormonal factors. Greater than expected fetal growth has been positively associated with the risk of the development of some cancers in childhood, particularly acute lymphoblastic leukemia, and the biological mechanisms underlying such associations are thought to involve insulin-like growth factors (IGFs). Circulating IGF levels are highly correlated with fetal growth, and IGFs are believed to play an important role in carcinogenesis; however, these two bodies of evidence have not been well integrated and, as a result, the potential underlying biological mechanisms linking the IGF system with the development of specific childhood cancers have not been elucidated. This review aims to draw together and summarize the literature linking the IGF system, rapidity of fetal growth, and risk of some specific childhood cancers; suggest explanations for some of the inconsistencies observed in previous studies of these associations; and propose an integrated framework for the putative involvement of the IGF system in the development of at least some childhood cancers. If the challenges involved in studying the complex IGF system can be overcome, this field presents an exciting opportunity to elucidate etiological pathways to childhood malignancies.

Mechanisms controlling anaemia in Trypanosoma congolense infected mice

Background

Trypanosoma congolense are extracellular protozoan parasites of the blood stream of artiodactyls and are one of the main constraints on cattle production in Africa. In cattle, anaemia is the key feature of disease and persists after parasitaemia has declined to low or undetectable levels, but treatment to clear the parasites usually resolves the anaemia.

Methodology/Principal Findings

The progress of anaemia after Trypanosoma congolense infection was followed in three mouse strains. Anaemia developed rapidly in all three strains until the peak of the first wave of parasitaemia. This was followed by a second phase, characterized by slower progress to severe anaemia in C57BL/6, by slow recovery in surviving A/J and a rapid recovery in BALB/c. There was no association between parasitaemia and severity of anaemia. Furthermore, functional T lymphocytes are not required for the induction of anaemia, since suppression of T cell activity with Cyclosporin A had neither an effect on the course of infection nor on anaemia. Expression of genes involved in erythropoiesis and iron metabolism was followed in spleen, liver and kidney tissues in the three strains of mice using microarrays. There was no evidence for a response to erythropoietin, consistent with anaemia of chronic disease, which is erythropoietin insensitive. However, the expression of transcription factors and genes involved in erythropoiesis and haemolysis did correlate with the expression of the inflammatory cytokines Il6 and Ifng.

Conclusions/Significance

The innate immune response appears to be the major contributor to the inflammation associated with anaemia since suppression of T cells with CsA had no observable effect. Several transcription factors regulating haematopoiesis, Tal1, Gata1, Zfpm1 and Klf1 were expressed at consistently lower levels in C57BL/6 mice suggesting that these mice have a lower haematopoietic capacity and therefore less ability to recover from haemolysis induced anaemia after infection.

B cells from patients with Graves' disease aberrantly express the IGF-1 receptor: implications for disease pathogenesis

Graves' disease (GD) is an autoimmune process involving the thyroid and connective tissues in the orbit and pretibial skin. Activating anti-thyrotropin receptor Abs are responsible for hyperthyroidism in GD. However, neither these autoAbs nor the receptor they are directed against have been convincingly implicated in the connective tissue manifestations. Insulin-like growth factor-1 receptor (IGF-1R)-bearing fibroblasts overpopulate connective tissues in GD and when ligated with IgGs from these patients, express the T cell chemoattractants, IL-16, and RANTES. Disproportionately large fractions of peripheral blood T cells also express IGF-1R in patients with GD and may account, at least in part, for expansion of IGF-1R(+) memory T cells. We now report a similarly skewed B cell population exhibiting the IGF-1R(+) phenotype from the blood, orbit, and bone marrow of patients with GD. This expression profile exhibits durability in culture and is maintained or increased with CpG activation. Moreover, IGF-1R(+) B cells produce pathogenic Abs against the thyrotropin receptor. In lymphocytes from patients with GD, IGF-1 enhanced IgG production (p < 0.05) and increased B cell expansion (p < 0.02) in vitro while those from control donors failed to respond. These findings suggest a potentially important role for IGF-1R display by B lymphocytes in patients with GD in supporting their expansion and abnormal Ig production.

Low insulin-like growth factor I and leukopenia in anorexia nervosa

OBJECTIVE

Considering that leukopenia and anemia are commonly observed in anorexia nervosa (AN) and that growth hormone (GH) and insulin-like growth factor-I (IGF-I) markedly influence the activation, growth and survival of hemopoietic cells, we sought for possible relationships between hematologic parameters and the GH-IGF-I axis in a group of patients with AN.

METHOD

Twenty patients were studied. Leukocyte and erythrocyte counts, as well as baseline serum GH levels and IGF-I standard deviation score (SDS) values, were determined in each participant and correlations between parameters were searched.

RESULTS

Leukocyte and erythrocyte counts, as well as IGF-I SDS values, were significantly lower, conversely GH was significantly higher in AN patients than in normal weight participants. In patients, IGF-I SDS values were positively correlated with leukocyte count and BMI, whereas no correlation was found between IGF-I SDS and hemoglobin or erythrocytes.

CONCLUSION

The demonstration of a positive correlation between leukocyte number and circulating IGF-I in AN suggests a likely pathogenetic role of IGF-I deficiency in this hematologic abnormality.

Insulin-like growth factor-binding protein 3 and hemoglobin concentration in older persons living in the community

A decreased hemoglobin concentration is a common clinical condition in elderly subjects, and in at least 20% of the cases it is not possible to directly attribute the anemia to specific factors. The aim of the present study was to evaluate the relationship of different levels of insulin-like growth factor-binding protein 3 (IGFBP-3) with the blood concentration of hemoglobin in persons aged 80 years and older. Data are from a baseline evaluation of the Aging and Longevity in the Sirente Geographic Area (ilSIRENTE) study (n=253). Analysis of covariance was used to examine the effect of different IGFBP-3 levels on hemoglobin concentration. After adjustment for potential confounding variables, which included age, sex, number of diseases, renal failure, cancer, gastric ulcer, albumin, and iron concentrations, individuals in the group with higher IGFBP-3 concentrations showed a significantly higher mean hemoglobin concentration than participants in the group with lower IGFBP-3 concentrations (13.4 +/- 1.4 g/dL versus 12.9 +/- 1.9 g/dL, respectively; P=.03). In conclusion, the present study has shown that a higher IGFBP-3 level is associated with a higher hemoglobin concentration among older people living in the community. This finding suggests that the growth hormone/IGF axis may play an important role in hematopoiesis, and it may be implicated in the age-related decline in hemoglobin concentration.

Aberrant expression of the insulin-like growth factor-1 receptor by T cells from patients with Graves' disease may carry functional consequences for disease pathogenesis

Graves' disease (GD), an autoimmune process involving thyroid and orbital tissue, is associated with lymphocyte abnormalities including expansion of memory T cells. Insulin-like growth factor receptor-1 (IGF-1R)-bearing fibroblasts overpopulate connective tissues in GD. IGF-1R on fibroblasts, when ligated with IgGs from these patients, results in the expression of the T cell chemoattractants, IL-16 and RANTES. We now report that a disproportionately large fraction of peripheral blood T cells express IGF-1R (CD3+IGF-R+). CD3+IGF-1R+ T cells comprise 48 +/- 4% (mean +/- SE; n = 33) in patients with GD compared with 15 +/- 3% (n = 21; p < 10(-8)) in controls. This increased population of IGF-1R+ T cells results, at least in part, from an expansion of CD45RO+ T cells expressing the receptor. In contrast, the fraction of CD45RA+IGF-1R+ T cells is similar in GD and controls. T cells harvested from affected orbital tissues in GD reflect similar differences in the proportion of IGF-1R+CD3+ and IGF-1R+CD4+CD3+ cells as those found in the peripheral circulation. GD-derived peripheral T cells express durable, constitutive IGF-1R expression in culture and receptor levels are further up-regulated following CD3 complex activation. IGF-1 enhanced GD-derived T cell incorporation of BrdU (p < 0.02) and inhibited Fas-mediated apoptosis (p < 0.02). These findings suggest a potential role for IGF-1R displayed by lymphocytes in supporting the expansion of memory T cells in GD.

Changes in DNA methylation patterns in subjects exposed to low-dose benzene

Aberrant DNA methylation patterns, including global hypomethylation, gene-specific hypermethylation/hypomethylation, and loss of imprinting (LOI), are common in acute myelogenous leukemia (AML) and other cancer tissues. We investigated for the first time whether such epigenetic changes are induced in healthy subjects by low-level exposure to benzene, a widespread pollutant associated with AML risk. Blood DNA samples and exposure data were obtained from subjects with different levels of benzene exposure, including 78 gas station attendants, 77 traffic police officers, and 58 unexposed referents in Milan, Italy (personal airborne benzene range, < 6-478 microg/m(3)). Bisulfite-PCR pyrosequencing was used to quantitate DNA methylation in long interspersed nuclear element-1 (LINE-1) and AluI repetitive elements as a surrogate of genome-wide methylation and examine gene-specific methylation of MAGE-1 and p15. Allele-specific pyrosequencing of the H19 gene was used to detect LOI in 96 subjects heterozygous for the H19 imprinting center G/A single-nucleotide polymorphism. Airborne benzene was associated with a significant reduction in LINE-1 (-2.33% for a 10-fold increase in airborne benzene levels; P = 0.009) and AluI (-1.00%; P = 0.027) methylation. Hypermethylation in p15 (+0.35%; P = 0.018) and hypomethylation in MAGE-1 (-0.49%; P = 0.049) were associated with increasing airborne benzene levels. LOI was found only in exposed subjects (4 of 73, 5.5%) and not in referents (0 of 23, 0.0%). However, LOI was not significantly associated with airborne benzene (P > 0.20). This is the first human study to link altered DNA methylation, reproducing the aberrant epigenetic patterns found in malignant cells, to low-level carcinogen exposure.

The WT1 Wilms' tumor suppressor gene is a downstream target for insulin-like growth factor-I (IGF-I) action in PC12 cells

The biological actions of the insulin-like growth factors, IGF-I and IGF-II, are mediated by the ligand-induced activation of the IGF-I receptor (IGF-IR), a transmembrane heterotetramer linked to the ras-raf-mitogen-activated protein kinase (MAPK) and phosphatidyl inositol 3 kinase (PI3K)-protein kinase B (PKB)/Akt signal transduction cascades. The Wilms' tumor suppressor gene (wt1) encodes a zinc finger transcription factor, WT1, which has been implicated in various cellular processes including proliferation, differentiation and apoptosis. In the present study we demonstrated that IGF-I modulates the WT1 gene expression in neurally derived PC12 cells in a dose- and time-dependent manner. This effect was mediated through both the MAPK and PI3-kinase signaling pathways, as shown by the ability of the specific inhibitors UO126 and LY294002 to abrogate IGF-I action. Moreover, using RT-PCR and transient transfection assays, we demonstrated that the IGF-I effect was associated with corresponding changes in WT1 mRNA levels and WT1 promoter activity. In addition, the results of the present study revealed that high WT1 levels were associated with the induction of apoptosis, whereas low WT1 levels were correlated with the inhibition of apoptosis, as demonstrated by poly ADP ribose polymerase (PARP) cleavage, Bax expression, Annexin V-FITC staining, and by the use of antisense oligonucleotides against WT1. In summary, our results show that the wt1 gene is a novel target for IGF-I action in neurally derived cells.

Statins in the treatment of polycythaemia vera and allied disorders: An antithrombotic and cytoreductive potential?

Thrombohaemorrhagic complications are major clinical problems in the classical chronic Ph-negative myeloproliferative disorders (CMPDs), polycytaemia vera (PV), essential thrombocythaemia (ET) and idiopathic myelofibrosis (IMF), contributing significantly to morbidity and mortality. Pathophysiologically these disorders are characterized by clonal myeloproliferation, myeloaccumulation and a propensity to develop myelofibrosis and neoangiogenesis in both the bone marrow and spleen. Based upon in vitro and in vivo studies of the effects of statins (antithrombotic, antiproliferative, proapoptotic and antiangiogenic), this review focuses on the translation of these effects into potential clinical benefits of statin therapy in patients with CMPDs.

IGF-I mediated survival pathways in normal and malignant cells

The type-I and -II insulin-like growth factors (IGF-I, II) are now established as survival- or proliferation-factors in many in vitro systems. Of note IGFs provide trophic support for multiple cell types or organ cultures explanted from various species, and delay the onset of programmed cell death (apoptosis) through the mitochondrial (intrinsic pathway) or by antagonizing activation of cytotoxic cytokine signaling (extrinsic pathway). In some instances, IGFs protect against other forms of death such as necrosis or autophagy. The effect of IGFs on cell survival appears to be context specific, being determined both by the cell origin (tissue specific) and the cellular stress that induces loss of cellular viability. In many human cancers, there is a strong association with dysregulated IGF signaling, and this association has been extensively reviewed recently. IGF-regulation is also disrupted in childhood cancers as a consequence of chromosomal translocations. IGFs are implicated also in acute renal failure, traumatic injury to brain tissue, and cardiac disease. This article focuses on the role of IGFs and their cellular signaling pathways that provide survival signals in stressed cells.

Targeting insulin-like growth factor pathways

Some cancer cells depend on the function of specific molecules for their growth, survival, and metastatic potential. Targeting of these critical molecules has arguably been the best therapy for cancer as demonstrated by the success of tamoxifen and trastuzumab in breast cancer. This review will evaluate the type I IGF receptor (IGF-IR) as a potential target for cancer therapy. As new drugs come forward targeting this receptor system, several issues will need to be addressed in the early clinical trials using these agents.

Molecular signatures of self-renewal, differentiation, and lineage choice in multipotential hemopoietic progenitor cells in vitro

The molecular mechanisms governing self-renewal, differentiation, and lineage specification remain unknown. Transcriptional profiling is likely to provide insight into these processes but, as yet, has been confined to "static" molecular profiles of stem and progenitors cells. We now provide a comprehensive, statistically robust, and "dynamic" analysis of multipotent hemopoietic progenitor cells undergoing self-renewal in response to interleukin-3 (IL-3) and multilineage differentiation in response to lineage-affiliated cytokines. Cells undergoing IL-3-dependent proliferative self-renewal displayed striking complexity, including expression of genes associated with different lineage programs, suggesting a highly responsive compartment poised to rapidly execute intrinsically or extrinsically initiated cell fate decisions. A remarkable general feature of early differentiation was a resolution of complexity through the downregulation of gene expression. Although effector genes characteristic of mature cells were upregulated late, coincident with morphological changes, lineage-specific changes in gene expression were observed prior to this, identifying genes which may provide early harbingers of unilineage commitment. Of particular interest were genes that displayed differential behavior irrespective of the lineage elaborated, many of which were rapidly downregulated within 4 to 8 h after exposure to a differentiation cue. These are likely to include genes important in self-renewal, the maintenance of multipotentiality, or the negative regulation of differentiation per se.

Acute lymphocytic leukemia in a child with Beckwith-Wiedemann syndrome

Beckwith-Wiedemann syndrome (BWS) is an overgrowth syndrome characterized by neonatal hypoglycemia, abdominal wall defects, macroglossia, organomegaly, ear pits and creases, hemihypertrophy, and increased birthweight. Children with BWS have an increased risk of malignancy. The authors present the case of a 3-year-old boy diagnosed with both BWS and acute lymphocytic leukemia (ALL). This case report will elaborate on the possibilities as to how BWS and ALL may be associated due to abnormal genomic imprinting and IGF dysregulation.

Changes in apoptosis-related pathways in acute myelocytic leukemia

Expression analysis of apoptotic genes was performed for 15 patients with acute myelocytic leukemia (AML) at the time of diagnosis to identify genes and signaling pathways involved in the regulation of cell survival and apoptosis during leukemogenesis. cDNA array analysis revealed 34 genes whose expression was significantly different compared to others. Tumor suppressor genes TP53 and CDKN2A were downregulated and protooncogenes JUN and GRB10 were upregulated. Furthermore, several cellular signaling pathways acting either in cell cycle regulation or in apoptosis were altered. Deregulation was found in pathways that contribute to genomic stability (by downregulation of either TP53 or CSE1L and by upregulation of GADD45A) and regulate cell cycle progression (by downregulation of CDKN2A and upregulation of RBBP4, CDC37, and NEDD5). Alterations at the transcriptional level were identified, namely, upregulation of JUN and E2F5. Abnormalities were observed in the regulation of the caspases through upregulation of CASP8 and by altered expression of BCL2-related pathway. Extrinsic apoptotic signals mediated by IGFs were deregulated and the glutathione detoxification pathway was downregulated. These findings provide insight into the regulation of balance between apoptosis and cell proliferation signals, and suggest that these genes and pathways may have an important role in the pathogenesis of AML.