scholarly journals Direct Conversion of Human Fibroblasts into Osteoblasts Triggered by Histone Deacetylase Inhibitor Valproic Acid

2020 ◽  
Vol 10 (20) ◽  
pp. 7372
Author(s):  
Hyeonjin Cha ◽  
Jaeyoung Lee ◽  
Hee Ho Park ◽  
Ju Hyun Park
Keyword(s):  
Valproic Acid ◽  
Alkaline Phosphatase ◽  
Histone Deacetylase ◽  
Hdac Inhibitor ◽  
Human Fibroblasts ◽  
Somatic Cells ◽  
Direct Conversion ◽  
Dermal Fibroblasts ◽  
Cellular Reprogramming ◽  
Osteogenic Medium

The generation of functional osteoblasts from human somatic cells could provide an alternative means of regenerative therapy for bone disorders such as osteoporosis. In this study, we demonstrated the direct phenotypic conversion of human dermal fibroblasts (HDFs) into osteoblasts by culturing them in osteogenic medium supplemented with valproic acid (VPA), a histone deacetylase (HDAC) inhibitor. HDFs cultured with the VPA in osteogenic medium exhibited expression of alkaline phosphatase and deposition of mineralized calcium matrices, which are phenotypical characteristics of functional osteoblasts. They also expressed osteoblast-specific genes such as alkaline phosphatase, osteopontin, and bone sialoprotein, which demonstrated their direct conversion into osteoblasts. In addition, co-treatment with VPA and a specific inhibitor for activin-like kinase 5 (ALK5i II) had a synergistic effect on direct conversion. It is considered that the inductive effect of VPA on the conversion into osteoblast-lineage is due to the opening of the nucleosome structure by HDAC inhibitor, which facilitates chromatin remodeling and cellular reprogramming. Our findings provide a novel insight into the direct conversion of human somatic cells into transgene-free osteoblasts with small chemical compounds, thus making bone regeneration using cellular reprogramming strategy more clinically feasible.

Die Kunst des Neuronenschmiedens: Direkte Reprogrammierung somatischer Zellen in induzierte neuronale Zellen

e-Neuroforum ◽  
2013 ◽  
Vol 19 (2) ◽  
Author(s):  
Marisa Karow ◽  
Benedikt Berninger
Keyword(s):  
Stem Cells ◽  
Neural Stem Cells ◽  
Neuronal Cells ◽  
Somatic Cells ◽  
Cell Types ◽  
Direct Conversion ◽  
Cellular Reprogramming ◽  
Direct Reprogramming ◽  
Brain Pericytes

AbstractThe art of forging neurons: direct reprogramming of somatic cells into induced neu­ronal cells.Cellular reprogramming has shed new light on the plasticity of terminally differentiated cells and discloses novel strategies for cell-based therapies for neurological disorders. With accumulating knowledge of the programs underlying the genesis of the distinct neural cell types, especially with the identification of relevant transcription factors and microRNAs, reprogramming of somatic cells of different origins into induced neuronal cells or neural stem cells has been successfully achieved. Starting with the general con­cept of reprogramming we discuss here three different paradigms: 1) direct conversion of CNS-foreign cells such as skin fibroblasts into induced neuronal cells or neural stem cells; 2) transdifferentiation of CNS resident cells such as astrocytes and brain pericytes into induced neuronal cells; 3) reprogramming of one neuronal subtype into another. The latter has already been successfully achieved in vivo during early brain develop­ment, providing strong impulse for the attempt to succeed in direct reprogramming in situ for future brain repair.

scholarly journals Highly efficient direct conversion of human monocytes into neuronal cells using a small molecule combination

2019 ◽  
Author(s):  
Itaru Ninomiya ◽  
Masato Kanazawa ◽  
Akihide Koyama ◽  
Masahiro Hatakeyama ◽  
Osamu Onodera
Keyword(s):  
Small Molecules ◽  
Peripheral Blood ◽  
Human Peripheral Blood ◽  
Human Fibroblasts ◽  
Neuronal Cells ◽  
Neuronal Cell ◽  
Direct Conversion ◽  
Dermal Fibroblasts ◽  
Blood Monocytes ◽  
Peripheral Blood Monocytes

SummaryPrevious studies reported that human fibroblasts and astrocytes were successfully converted into neuronal cells by small molecules without introducing ectopic transgenes. Induced neuronal cells—reprogrammed directly from dermal fibroblasts or brain astrocytes—were obtained from some donors; however, the clinical applications of this approach would be limited because it requires an invasive biopsy to harvest enough cells for derivation. Here, we report that adult human peripheral blood monocytes may be directly converted into neuron-like cells using only a combination of small molecules without transgene integration. This method enables neuronal cell generation from TUJ1-positive cells after 3 days of induction (at over 80% conversion efficacy). These cells presented neuronal morphologies and markers, suggesting that terminally differentiated human cells may be efficiently transdifferentiated into a distantly related lineage. Overall, our study provides a strategy to develop neuronal cells directly from human adult peripheral blood monocytes using a generate transgene-free, chemical-only approach.

Valproic Acid (VPA), a Histone Deacetylase (HDAC) Inhibitor, Diminishes Lymphoproliferation in the Fas Deficient MRL/lpr−/− Murine Model of Autoimmune Lymphoproliferative Syndrome (ALPS).

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 2497-2497
Author(s):  
Kennichi C. Dowdell ◽  
Lesley Pesnicak ◽  
Victoria Hoffman ◽  
Kenneth Steadman ◽  
Mark Ruddel ◽  
...  
Keyword(s):  
Valproic Acid ◽  
Cell Death ◽  
Lymph Nodes ◽  
Histone Deacetylase ◽  
Murine Model ◽  
Hdac Inhibitor ◽  
Vitro Assay ◽  
Type Ia ◽  
Autoimmune Cytopenias

Abstract ALPS is an inherited disorder of apoptosis leading to lymphoproliferation and autoimmunity. ALPS Type Ia, Ib and II are associated with germline mutations in Fas, FasL and Casapase 8 or 10, respectively; patients in whom no mutations have been identified are classified as Type III. The vast majority of patients are ALPS Type Ia (greater than 70%). They often present with childhood onset autoimmune cytopenias associated with lymphadenopathy, splenomegaly, increased double negative T cells (DNT; TCRα/β+CD3+CD4−CD8−), defective apoptosis by in vitro assay, and have an increased risk of lymphoma. Similarly, MRL/lpr−/− mice homozygous for Fas mutations develop an ALPS-like disease with massive lymphadenopathy, splenomegaly, hypergammaglobulinemia, autoimmune glomerulonephritis, and expansion of DNT cells secondary to defective lymphocyte apoptosis leading to lymphomagenesis. Currently, there are no proven therapies for the lymphoproliferation underlying ALPS itself, although complications like autoimmune cytopenias and post-splenectomy sepsis are manageable. Hence, studies were conducted to determine the efficacy of valproic acid (VPA) to control the lymphoproliferation associated with ALPS. VPA is a histone deacetylase (HDAC) inhibitor in clinical use for the last four decades as an anticonvulsant in children and adults, and recently being explored as an anti-neoplastic agent. PBMCs from normal controls and ALPS Type Ia patients were cultured in vitro with 0–4 mM VPA in the presence or absence of 50 uM of the pan-caspase inhibitor Z-VAD-FMK. A dose response was observed with a high degree of cell death noted at 4 mM after 48 hours, with an LD50 of 2 mM. VPA appeared to induce cell death by both caspase-dependent and -independent mechanisms based on partial inhibition of VPA-induced cell death by Z-VAD-FMK. Further preclinical studies were conducted in the MRL/lpr−/− murine model of ALPS. Twenty, 8-week old female MRL/lpr−/− mice were treated intraperitoneally (i.p.) with 500 mg/kg of VPA in sterile PBS or PBS alone five days per week for 8 weeks. Significant reduction of the spleen weight (p=0.034) and cellularity (p=0.0001) was observed in VPA treated (n=10) mice compared to controls (n=10). Reductions in size and cellularity were also observed in the lymph nodes (p=0.09 and 0.0002, respectively). A concomitant decrease (p<0.05) in DNT cells was observed in the spleen (11.2±0.6 vs 8.1±0.4) and blood (9.3±0.96 vs 5.5±0.6). Serum drug levels peaked (462±10 ug/mL) by 2 hours post-i.p. injection of VPA, where-as a 2.5 fold increase in histone acetylation was observed in the spleen at 4 hours, following a single injection. Analysis of the effects of VPA on autoimmune renal disease in these animals is underway. Based on our in vitro and in vivo data, VPA is effective at reducing lymphoproliferative activity in Fas deficient MRL/lpr−/− mice. It is being further explored in early phase clinical trials as a lympholytic agent to shrink lymph nodes and abrogate hypersplenism in ALPS patients.

scholarly journals Placenta to cartilage: direct conversion of human placenta to chondrocytes with transformation by defined factors

2012 ◽  
Vol 23 (18) ◽  
pp. 3511-3521 ◽  
Author(s):  
Ryuga Ishii ◽  
Daisuke Kami ◽  
Masashi Toyoda ◽  
Hatsune Makino ◽  
Satoshi Gojo ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Human Fibroblasts ◽  
Direct Conversion ◽  
Cellular Reprogramming ◽  
Irreversible Processes ◽  
Cell Based Therapy ◽  
Decidual Cells ◽  
Cell Conversion

Cellular differentiation and lineage commitment are considered to be robust and irreversible processes during development. Recent work has shown that mouse and human fibroblasts can be reprogrammed to a pluripotent state with a combination of four transcription factors. We hypothesized that combinatorial expression of chondrocyte-specific transcription factors could directly convert human placental cells into chondrocytes. Starting from a pool of candidate genes, we identified a combination of only five genes (5F pool)—BCL6, T (also called BRACHYURY), c-MYC, MITF, and BAF60C (also called SMARCD3)—that rapidly and efficiently convert postnatal human chorion and decidual cells into chondrocytes. The cells generated expressed multiple cartilage-specific genes, such as Collagen type II α1, LINK PROTEIN-1, and AGGRECAN, and exhibited characteristics of cartilage both in vivo and in vitro. Expression of the endogenous genes for T and MITF was initiated, implying that the cell conversion is due to not only the forced expression of the transgenes, but also to cellular reprogramming by the transgenes. This direct conversion system from noncartilage tissue to cartilaginous tissue is a substantial advance toward understanding cartilage development, cell-based therapy, and oncogenesis of chondrocytes.

The art of forging neurons: direct reprogramming of somatic cells into induced neuronal cells

e-Neuroforum ◽  
2013 ◽  
Vol 19 (2) ◽  
Author(s):  
M. Karow ◽  
B. Berninger
Keyword(s):  
Stem Cells ◽  
Neural Stem Cells ◽  
Neuronal Cells ◽  
Somatic Cells ◽  
Cell Types ◽  
Direct Conversion ◽  
Cellular Reprogramming ◽  
Direct Reprogramming ◽  
Brain Pericytes

AbstractCellular reprogramming has shed new light on the plasticity of terminally differentiated cells and unearthed novel strategies for cell-based therapies to treat neurological disor­ders. With accumulating knowledge of the programs underlying the genesis of the dis­tinct neural cell types, particularly the iden­tification of crucial transcription factors and microRNAs, reprogramming of somatic cells of different origins into induced neuronal cells or neural stem cells has been success­fully achieved. Starting with the general con­cept of reprogramming, we discuss three dif­ferent paradigms: (1) direct conversion of central nervous system (CNS) foreign cells such as skin fibroblasts into induced neuro­nal cells or neural stem cells; (2) transdiffer­entiation of CNS resident cells such as astro­cytes and brain pericytes into induced neuro­nal cells; (3) reprogramming of one neuronal subtype into another. The latter has already been successfully achieved in vivo during ear­ly brain development, providing a strong im­pulse to attempt direct reprogramming in si­tu for future brain repair.

scholarly journals 5-Aza-2′-Deoxycytidine and Valproic Acid in Combination with CHIR99021 and A83-01 Induce Pluripotency Genes Expression in Human Adult Somatic Cells

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 1909
Author(s):  
Alain Aguirre-Vázquez ◽  
Luis A. Salazar-Olivo ◽  
Xóchitl Flores-Ponce ◽  
Ana L. Arriaga-Guerrero ◽  
Dariela Garza-Rodríguez ◽  
...  
Keyword(s):  
Valproic Acid ◽  
Disease Modeling ◽  
Morphological Changes ◽  
Somatic Cells ◽  
Ectopic Expression ◽  
Dermal Fibroblasts ◽  
Klf4 Expression ◽  
Genes Expression ◽  
Induced Pluripotent ◽  
Pluripotency Genes

A generation of induced pluripotent stem cells (iPSC) by ectopic expression of OCT4, SOX2, KLF4, and c-MYC has established promising opportunities for stem cell research, drug discovery, and disease modeling. While this forced genetic expression represents an advantage, there will always be an issue with genomic instability and transient pluripotency genes reactivation that might preclude their clinical application. During the reprogramming process, a somatic cell must undergo several epigenetic modifications to induce groups of genes capable of reactivating the endogenous pluripotency core. Here, looking to increase the reprograming efficiency in somatic cells, we evaluated the effect of epigenetic molecules 5-aza-2′-deoxycytidine (5AZ) and valproic acid (VPA) and two small molecules reported as reprogramming enhancers, CHIR99021 and A83-01, on the expression of pluripotency genes and the methylation profile of the OCT4 promoter in a human dermal fibroblasts cell strain. The addition of this cocktail to culture medium increased the expression of OCT4, SOX2, and KLF4 expression by 2.1-fold, 8.5-fold, and 2-fold, respectively, with respect to controls; concomitantly, a reduction in methylated CpG sites in OCT4 promoter region was observed. The epigenetic cocktail also induced the expression of the metastasis-associated gene S100A4. However, the epigenetic cocktail did not induce the morphological changes characteristic of the reprogramming process. In summary, 5AZ, VPA, CHIR99021, and A83-01 induced the expression of OCT4 and SOX2, two critical genes for iPSC. Future studies will allow us to precise the mechanisms by which these compounds exert their reprogramming effects.

scholarly journals The histone deacetylase (HDAC) inhibitor valproic acid as monotherapy or in combination with all-trans retinoic acid in patients with acute myeloid leukemia

Cancer ◽  
2006 ◽  
Vol 106 (1) ◽  
pp. 112-119 ◽  
Author(s):  
Andrea Kuendgen ◽  
Mathias Schmid ◽  
Richard Schlenk ◽  
Sabine Knipp ◽  
Barbara Hildebrandt ◽  
...  
Keyword(s):  
Valproic Acid ◽  
Acute Myeloid Leukemia ◽  
Retinoic Acid ◽  
Histone Deacetylase ◽  
Hdac Inhibitor ◽  
Myeloid Leukemia ◽  
Trans Retinoic Acid ◽  
All Trans Retinoic Acid ◽  
Acute Myeloid
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