Global miRNA expression of bone marrow mesenchymal stem/stromal cells derived from Fanconi anemia patients

Global microRNA profiling of bone marrow-MSC derived extracellular vesicles identifies miRNAs associated with hematopoietic dysfunction in aplastic anemia

Recently, we have reported that extracellular vesicles (EVs) from the bone marrow mesenchymal stromal cells (BM-MSC) of aplastic anemia (AA) patients inhibit hematopoietic stem and progenitor cell (HSPC) proliferative and colony-forming ability and promote apoptosis. One mechanism by which AA BM-MSC EVs might contribute to these altered HSPC functions is through microRNAs (miRNAs) encapsulated in EVs. However, little is known about the role of BM-MSC EVs derived miRNAs in regulating HSPC functions in AA. Therefore, we performed miRNA profiling of EVs from BM-MSC of AA (n = 6) and normal controls (NC) (n = 6) to identify differentially expressed miRNAs. The Integrated DEseq2 analysis revealed 34 significantly altered mature miRNAs, targeting 235 differentially expressed HSPC genes in AA. Hub gene analysis revealed 10 HSPC genes such as IGF-1R, IGF2R, PAK1, PTPN1, etc., which are targeted by EV miRNAs and had an enrichment of chemokine, MAPK, NK cell-mediated cytotoxicity, Rap1, PI3k-Akt, mTOR signalling pathways which are associated with hematopoietic homeostasis. We further showed that miR-139-5p and its target, IGF-1R (hub-gene), might regulate HSPC proliferation and apoptosis, which may serve as potential therapeutic targets in AA. Overall, the study highlights that AA BM-MSC EV miRNAs could contribute to impaired HSPC functions in AA.

Integrative investigation of hematotoxic effects induced by low doses of lead, cadmium, mercury and arsenic mixture: In vivo and in silico approach

The effect of the lead (Pb), cadmium (Cd), mercury (Hg) and arsenic (As) mixture (MIX) on hematotoxicity development was investigated trough combined approach. In vivo subacute study (28 days) was performed on rats (5 per group): a control group and five groups orally exposed to increasing metal(loid) mixture doses, MIX 1- MIX 5 (mg/kg bw./day) (Pb: 0.003, 0.01, 0.1, 0.3, 1; Cd: 0.01, 0.03, 0.3, 0.9, 3; Hg: 0.0002, 0.0006, 0.006, 0.018, 0.06; As: 0.002, 0.006, 0.06, 0.18, 0.6). Blood was taken for analysis of hematological parameters and serum iron (Fe) analysis. MIX treatment increased thrombocyte/platelet count and MCHC and decreased Hb, HCT, MCV and MCH values compared to control, indicating the development of anemia and thrombocytosis. BMDIs with the narrowest width were identified for MCH [pg] (6.030E-03 - 1.287E-01 mg Pb/kg bw./day; 2.010E-02 - 4.290E-01 mg Cd/kg bw./day; 4.020E-04 - 8.580E-03 mg Hg/kg bw./day; 4.020E-03 - 8.580E-02 mg As/kg bw./day). In silico analysis showed target genes connected with MIX and the development of: anemia - ACHE, GSR, PARP1, TNF; thrombocytosis - JAK2, CALR, MPL, THPO; hematological diseases - FAS and ALAD. The main extracted pathways for anemia were related to apoptosis and oxidative stress; for thrombocytosis were signaling pathways of Jak-STAT and TPO. Changes in miRNAs and transcription factors enabled the mode of action (MoA) development based on the obtained results, contributing to mechanistic understanding and hematological risk related to MIX exposure.

Multiparametric analysis of etoposide exposed mesenchymal stem cells and Fanconi anemia cells: implications in development of secondary myeloid malignancy

Secondary acute myeloid leukemia (sAML) may develop following a prior therapy or may evolve from an antecedent hematological disorder such as Fanconi Anemia (FA). Pathophysiology of leukemic evolution is not clear. Etoposide (Eto) is a chemotherapeutic agent implicated in development of sAML. FA is an inherited bone marrow (BM) failure disease characterized by genomic instability and xenobiotic susceptibility. Here, we hypothesized that alterations in the BM niche may play a critical/driver role in development of sAML in both conditions. Expression of selected genes involved in xenobiotic metabolism, DNA double-strand break response, endoplasmic reticulum (ER) stress, heat shock response and cell cycle regulation were determined in BM mesenchymal stem cells (MSCs) of healthy controls and FA patients at steady state and upon exposure to Eto at different concentrations and in recurrent doses. Expression of CYPA1, p53, CCNB1, Dicer1, CXCL12, FLT3L and TGF-Beta genes were significantly downregulated in FA-MSCs compared with healthy controls. Eto exposure induced significant alterations in healthy BM-MSCs with increased expression of CYP1A1, GAD34, ATF4, NUPR1, CXCL12, KLF4, CCNB1 and nuclear localization of Dicer1. Interestingly, FA-MSCs did not show significant alterations in these genes upon Eto exposure. As opposed to healthy MSCs DICER1 gene expression and intracellular localization was not altered on FA BM-MSCs after Eto treatment. These results showed that Eto is a highly potent molecule and has pleiotropic effects on BM-MSCs, FA cells show altered expression profile compared to healthy controls and Eto exposure on FA cells shows differential profile than healthy controls.