Fatima Aerts | Hacettepe University (original) (raw)

Papers by Fatima Aerts

Research Square (Research Square), Jul 18, 2023

RAG2 deficiency is characterized by a lack of B and T lymphocytes, causing severe lethal infectio... more RAG2 deficiency is characterized by a lack of B and T lymphocytes, causing severe lethal infections. Currently, RAG2 deficiency is treated with a Hematopoietic Stem Cell transplantation (HSCT). Most conditioning regimens used before HSCT consist of alkylating myelotoxic agents with or without irradiation and affect growth and development of pediatric patients. Here, we developed a non-myelotoxic regimen using G-CSF, VLA-4I or AMD3100. These agents are known HSC mobilizers or affect bone marrow (BM) permeability and may support the homing of HSCs to the BM, without inducing major side effects. Female Rag2-/mice were pre-treated with Busulfan (BU), G-CSF, VLA-4I or AMD3100 and transplanted with male BM cells transduced with a lentiviral vector carrying codon optimized human RAG2 (RAG2co). Peripheral blood cell counts increased significantly after G-CSF, VLA-4I and AMD3100 treatment, but not after BU. Reconstitution of PB lymphocytes was comparable for all groups with full immune reconstitution at 6 months post transplantation, despite different methods of conditioning. Survival of mice pre-treated with non-myelotoxic agents was significantly higher than after BU treatment. Here we show that the nonmyelotoxic agents G-CSF, VLA-4I, and AMD3100 are highly effective as conditioning regimen before HSC gene therapy and can be used instead of BU.

Hematopoetik kök hücreler (HKH), kök hücre nişi olarak da adlandırılan özel bir mikroçevrede bulu... more Hematopoetik kök hücreler (HKH), kök hücre nişi olarak da adlandırılan özel bir mikroçevrede bulunur. Bu mikrocevrede mezenkimal kök hucreler (MKH), endotelyal hücreler (EH), retiküler hücreler bulunur. Perivasküler mikroortamda bulunan EH, MKH, makrofajlar ve HKH yaşamını ve kemik iliği rejenerasyonunu düzenler.Nörotransmitter nöropeptit Y (NPY), makrofajlardan ve osteoblastlardan salınır. NPY, immün ve kemik hücre homeostazını veya bu yapıların vasküler yeniden yapılanmasını, kemik iliği hücrelerinde ifade edilen Y reseptörüyle düzenlerler. Hibernasyonda HKH'ler sıklıkla trabeküler endosteuma yakın bulunurlar. İhtiyaç duyulduğunda bu hücreler çoğalır ve farklılaşır, stres ve yaralanmalarda salgılanan büyüme faktörleri ile hücre döngüsüne girerler. NPY eksikliğinde, HKH’lerin sayıları düşmekte ve kemik iliği rejenerasyonu bozulmaktadır. Önerilen projenin amacı, NPY ve NPY reseptör sinyal yolağı etkisiyle HKH'lerin uyku durumuna geri dönmesi ve HKH havuz boyutu ile kemik iliği fonksiyonunun korunmasında sessizliğin rolünün ortaya çıkmasına ilişkin anahtar bir mekanizmanın belirlenmesidir

Molecular and Cellular Biochemistry

Human Cell, 2021

Fanconi anemia (FA) is a rare genetic disorder characterized by genomic instability, developmenta... more Fanconi anemia (FA) is a rare genetic disorder characterized by genomic instability, developmental defects, and bone marrow (BM) failure. Hematopoietic stem cells (HSCs) in BM interact with the mesenchymal stem/stromal cells (MSCs); and this partly sustains the tissue homeostasis. MicroRNAs (miRNAs) can play a critical role during these interactions possibly via paracrine mechanisms. This is the first study addressing the miRNA profile of FA BM-MSCs obtained before and after BM transplantation (preBMT and postBMT, respectively). Non-coding RNA expression profiling and quality control analyses were performed in Donors (n = 13), FA preBMT (n = 11), and FA postBMT (n = 6) BM-MSCs using GeneChip miRNA 2.0 Array. Six Donor-FA preBMT pairs were used to identify a differentially expressed miRNA expression signature containing 50 miRNAs, which exhibited a strong correlation with the signature obtained from unpaired samples. Five miRNAs (hsa-miR-146a-5p, hsa-miR-148b-3p, hsa-miR-187-3p, hsa-miR-196b-5p, and hsa-miR-25-3p) significantly downregulated in both the paired and unpaired analyses were used to generate the BM-MSCs' miRNA-BM mononuclear mRNA networks upon integration of a public dataset (GSE16334; studying Donor versus FA samples). Functionally enriched KEGG pathways included cellular senescence, miRNAs, and pathways in cancer. Here, we showed that hsa-miR-146a-5p and hsa-miR-874-3p were rescued upon BMT (n = 3 triplets). The decrease in miR-146a-5p was also validated using RT-qPCR and emerged as a strong candidate as a modulator of BM mRNAs in FA patients.

Methods in molecular biology, 2021

Here, we describe a protocol for reprogramming of bone marrow-derived multipotent mesenchymal str... more Here, we describe a protocol for reprogramming of bone marrow-derived multipotent mesenchymal stromal/stem cells to obtain induced pluripotent stem cells from patients with primary immune deficiencies using lentiviral vectors, followed by hematopoietic differentiation of the MSC-derived iPSCs. This protocol is particularly helpful in cases where it is difficult to obtain sufficient numbers of hematopoietic cells for research and can be applied to model any hematological/immunological disease.

Additional file 1: Figure S1. Karyotype analysis of healthy donor and GS-2 iPSC clones. For karyo... more Additional file 1: Figure S1. Karyotype analysis of healthy donor and GS-2 iPSC clones. For karyotyping, iPSC cultures were trypsinized and treated with a hypotonic salt solution. 10 metaphases were captured and analysed. Shown here are the karyotypes of a healthy donor (left, GP) and the 3 GS-2 patient-derived iPSCs (IK, YF, YKÇ). Figure S2. Upper panel: iPSCs were co-cultured with Op9 cells in presence of HDM2 medium (StemMACS HSC expansion medium, 1X STF, 10 μg/mL rhBMP-4), resulting in low level expression of CD34. Lower panel: further expansion of iPSC-derived HSCs in StemMACS HSC expansion medium, 1X STF for 21 days resulted in expansion of CD43+, CD34+, CD45+ HSCs. Table S1. Primer sequences used for RT-PCR. Table S2. Differentiation capacity of healthy donor and GS-2 BM-MSCs. For adipogenic differentiation, MSCs were cultured in DMEM-LG, supplemented with 10% FBS, 1 μM dexamethasone, 60 μM indometacin, 500 μM 3-isobutyl-1-methylxanthine and 5 μg/mL insulin. After 3 weeks, ce...

Biotechnic & Histochemistry, 2021

Multipotent mesenchymal stromal cells (MSC) can be isolated from many tissues, including bone mar... more Multipotent mesenchymal stromal cells (MSC) can be isolated from many tissues, including bone marrow (BM) and placenta (PL). Human placenta can be obtained readily without invasive procedures. There may be differences, however, in differentiation capacity and immunomodulation by MSC isolated from BM or PL. The early pregnancy factor (heat shock protein 10; EPF/Hsp10) is a small protein that exhibits immunomodulatory properties. We compared BM- and PL-MSC, and assessed their efficacy for suppressing T-cell proliferation in vitro and the role of EPF/Hsp10 in this process. PL-MSC were collected from whole placenta after removal of the amniotic and chorionic membranes followed by serial enzymatic digestions. The PL-MSC were compared to BM-MSC, obtained from healthy donors. Differentiation capacity, cytokine secretion, expression and secretion of immunomodulatory molecules, immunophenotype and real time proliferation were assessed using cytokine arrays, ELISA assays, flow cytometry, immunohistochemical staining and western blotting. Whereas BM-MSC consisted of a homogeneous cell population with strong expression of mesenchymal markers, PL-MSC consisted of a mixed population of cells with variable CD73, CD90 and CD105 expression. PL-MSC exhibited a significantly greater proliferation rate than BM-MSC. The presence of both stem cells and more mature cells in the PL-MSC cultures resulted in decreased differentiation capacity and reduced efficacy of immune suppression in co-cultures with T-cells. Although robust intracellular expression of EPF/Hsp10 in both BM- and PL-MSC was observed, secretion of the protein in response to immune activating stimuli remained below detectable levels. Secretion of pro-inflammatory cytokines was significantly greater in BM-MSC than PL-MSC, whereas no difference was observed in the secretion of hematopoiesis supporting growth factors. Development of culture methods for isolation of pure populations of PL-MSC may improve the quality of the product and reproducibility of results.

Liver Transplantation, 2011

Biology of Blood and Marrow Transplantation, 2012

Summary Host immune responses play a major role in clearance of viral infections from the body, a... more Summary Host immune responses play a major role in clearance of viral infections from the body, and may limit long-term expression and clinical efficacy of viral vectors. Methods to prevent these immune responses may also increase the risk for infections, recombination with wild type virus and affect biodistribution, persistence, shedding and transmission. The study described in this report was initiated to assess possible environmental risks associated with the use of immune modulation in combination with gene therapy and set up as a literature study, by performing PubMed searches for certain keywords, by interviewing experts and by attending selected meetings. Lack of availability of clinical data combining gene therapy and immune modulation and limited animal data warranted additional exploration of relevant non-gene therapy studies from closely related fields such as stem cell and organ transplantation, and vaccination studies with live attenuated vaccines. ...... Finally, we pr...

Mammadova A., Assessment of the Role and Antioxidative and Antiapoptotic Effects of Delta-opioid ... more Mammadova A., Assessment of the Role and Antioxidative and Antiapoptotic Effects of Delta-opioid Peptide D-Ala2-Leu5-Enkephalin on the viability of Hematopoietic Stem Cells, Hacettepe University Graduate School of Health Sciences Stem Cell Program Master Thesis, Ankara, 2019. Hematopoietic Stem Cells (HSCs) are adult stem cells with the capacity for self-renewal and differentiation into all blood cell lineages. When HSCs are used for transplantation or gene therapy purposes, they can be exposed to short term cell culture and/or freezing procedures. However, the viability and function of HSCs may be negatively affected by oxidative and endoplasmic reticulum stress induced by these processes. There is a need for the development of novel short term HSC expansion protocols that are highly effective, non-toxic and protect cell viability. Therefore, in the framework of this thesis, the role of Delta Opioid Receptor (DOR) activating synthetic peptid D-Ala2-Leu5-Enkephalı̇n (DADLE) on in vi...

Since the start of the coronavirus SARS-CoV2 (COVID-19) outbreak in China, in the end of 2019, th... more Since the start of the coronavirus SARS-CoV2 (COVID-19) outbreak in China, in the end of 2019, the virus has rapidly spread throughout the World, causing a path of destruction behind it, with mortality figures exceeding 7.000.000 globally, and a death toll reaching numbers of over 400.000. Economically, the pandemic has been estimated to cause a Worldwide crise similar or worse than World War II. While physians are just barely able to cope with the amount of patients, lack of knowledge on the pathogenesis of the disease, its targets and possible effective treatments are major hurdles in the design of proper treatment strategies. Current treatment options using a variety of anti-viral, anti-bacterial and other drugs, have shown to be often insufficient and in severe cases of COVID-19 disease, the use of stem cells, and in particular mesenchymal stem cells, has been proposed as auxiliary treatment, based on their proven capacity for potent immunomodulation and tissue regeneration. Here, we provide a brief overview of current data on the use of MSCs for treatment of COVID-19.

The Oncologist

Volume 21 Acknowledgments The Oncologist could not maintain its standard of excellence without th... more Volume 21 Acknowledgments The Oncologist could not maintain its standard of excellence without the invaluable contributions of its Section Editors, who use their collective expertise to ensure the quality, accuracy, and potential for positive impact of the articles in our publication.We are likewise indebted to the dedicated individuals who have reviewed and commented upon hundreds of manuscripts this past year.

Advances in experimental medicine and biology, 2021

Lysosomal storage disorders (LSDs) are rare inborn errors of metabolism caused by defects in lyso... more Lysosomal storage disorders (LSDs) are rare inborn errors of metabolism caused by defects in lysosomal function. These diseases are characterized by accumulation of completely or partially degraded substrates in the lysosomes leading to cellular dysfunction of the affected cells. Currently, enzyme replacement therapies (ERTs), treatments directed at substrate reduction (SRT), and hematopoietic stem cell (HSC) transplantation are the only treatment options for LSDs, and the effects of these treatments depend strongly on the type of LSD and the time of initiation of treatment. However, some of the LSDs still lack a durable and curative treatment. Therefore, a variety of novel treatments for LSD patients has been developed in the past few years. However, despite significant progress, the efficacy of some of these treatments remains limited because these therapies are often initiated after irreversible organ damage has occurred.Here, we provide an overview of the known effects of LSDs o...

Stem Cell Research & Therapy

Background Griscelli syndrome type 2 (GS-2) is a rare, autosomal recessive immune deficiency synd... more Background Griscelli syndrome type 2 (GS-2) is a rare, autosomal recessive immune deficiency syndrome caused by a mutation in the RAB27A gene, which results in the absence of a protein involved in vesicle trafficking and consequent loss of function of in particular cytotoxic T and NK cells. Induced pluripotent stem cells (iPSC) express genes associated with pluripotency, have the capacity for infinite expansion, and can differentiate into cells from all three germ layers. They can be induced using integrative or non-integrative systems for transfer of the Oct4, Sox2, Klf4, and cMyc (OSKM) transcription factors. To better understand the pathophysiology of GS-2 and to test novel treatment options, there is a need for an in vitro model of GS-2. Methods Here, we generated iPSCs from 3 different GS-2 patients using lentiviral vectors. The iPSCs were characterized using flow cytometry and RT-PCR and tested for the expression of pluripotency markers. In vivo differentiation to cells from a...