Use of CombiMag to successfully improve the viral transduction efficiency in primary HSCs – LSK cells

p38a Activates Purine Metabolism to Initiate Hematopoietic Stem/Progenitor Cell Cycling in Response to Stress

Cell Stem Cell, 2016
D. Karigane et al

Abstract 

Hematopoietic stem cells (HSCs) maintain quiescence by activating specific metabolic pathways, including glycolysis. We do not yet have a clear understanding of how this metabolic activity changes during stress hematopoiesis, such as bone marrow transplantation. Here, we report a critical role for the p38MAPK family isoform p38α in initiating hematopoietic stem and progenitor cell (HSPC) proliferation during stress hematopoiesis in mice. We found that p38MAPK is immediately phosphorylated in HSPCs after a hematological stress, preceding increased HSPC cycling. Conditional deletion of p38α led to defective recovery from hematological stress and a delay in initiation of HSPC proliferation. Mechanistically, p38α signaling increases expression of inosine-5′-monophosphate dehydrogenase 2 in HSPCs, leading to altered levels of amino acids and purine-related metabolites and changes in cell-cycle progression in vitro and in vivo. Our studies have therefore uncovered a p38α-mediated pathway that alters HSPC metabolism to respond to stress and promote recovery.

Hematopoietic Stem Cells transfection with retrovirus using ViroMag

The LSK cell fraction of HSC was transduced with retrovirus on retronectin using ViroMag.

The paper shows the high efficiency of Magnetofection method from OZ Biosciences to improve infection and transduction capacity on hematopoietic stem cells.

article reference: Biochem Biophys Res Commun. 2013 Oct 16.

Nucleostemin is indispensable for the maintenance and genetic stability of hematopoietic stem cells.

Yamashita M, Nitta E, Nagamatsu G, Ikushima YM, Hosokawa K, Arai F, Suda T.

Abstract
Nucleostemin is a nucleolar protein known to play a variety of roles in cell-cycle progression, apoptosis inhibition, and DNA damage protection in embryonic stem cells and tissue stem cells. However, the role of nucleostemin in hematopoietic stem cells (HSCs) is yet to be determined. Here, we identified an indispensable role of nucleostemin in mouse HSCs. Depletion of nucleostemin using short hairpin RNA strikingly impaired the self-renewal activity of HSCs both in vitro and in vivo. Consistently, loss of nucleostemin triggered apoptosis rather than cell-cycle arrest in HSCs. Furthermore, DNA damage accumulated during cultivation upon depletion of nucleostemin. The impaired self-renewal activity of HSCs induced by nucleostemin depletion was partially rescued by p53 deficiency but not by p16^Ink4a or p19^Arf deficiency. Taken together, our study demonstrates that nucleostemin protects HSCs from DNA damage accumulation and is required for the maintenance of HSCs.

ViroMag from OZ Biosciences is a magnetic nanoparticles formulation optimized for increasing any kind of virus infection and transduction both in vitro and in vivo.

Hematopoietic Stem cells transfection with retrovirus using ViroMag

The LSK cell fraction of HSC was transduced with retrovirus-shEP4 on retronectin using ViroMag.

The paper shows the high efficiency of Magnetofection method from OZ Biosciences to improve infection and transduction capacity on hematopoietic stem cells.

article reference: Blood. 2013 Mar 14;121(11):1995-2007.

Prostaglandin E2 regulates murine hematopoietic stem/progenitor cells directly via EP4 receptor and indirectly through mesenchymal progenitor cells.

Ikushima YM, Arai F, Hosokawa K, Toyama H, Takubo K, Furuyashiki T, Narumiya S, Suda T.

Abstract

Prostaglandin E2 (PGE2) regulates hematopoietic stem/progenitor cell (HSPC) activity. However, the receptor(s) responsible for PGE2 signaling remains unclear. Here, we identified EP4 as a receptor activated by PGE2 to regulate HSPCs. Knockdown of Ep4 in HSPCs reduced long-term reconstitution capacity, whereas an EP4-selective agonist induced phosphorylation of GSK3β and β-catenin and enhanced long-term reconstitution capacity. Next, we analyzed the niche-mediated effect of PGE2 in HSPC regulation. Bone marrow mesenchymal progenitor cells (MPCs) expressed EP receptors, and stimulation of MPCs with PGE2 significantly increased their ability to support HSPC colony formation. Among the EP receptor agonists, only an EP4 agonist facilitated the formation of HSPC colonies after the coculture with MPCs. PGE2 up-regulated the expression of cytokine-, cell adhesion-, extracellular matrix-, and protease-related genes in MPCs. We also examined the function of PGE2/EP4 signaling in the recovery of the HSPCs after myelosuppression. The administration of PGE2 or an EP4 agonist facilitated the recovery of HSPCs from 5-fluorouracil (5-FU)-induced myelosuppression, indicating a role for PGE2/EP4 signaling in this process. Altogether, these data suggest that EP4 is a key receptor for PGE2-mediated direct and indirect regulation of HSPCs.

ViroMag R/L from OZ Biosciences is a magnetic nanoparticles formulation optimized for increasing any kind of virus infection and transduction both in vitro and in vivo.