MicroRNAs profoundly impact hematopoietic cells by regulating progenitor cell-fate decisions, as well as mature immune effector function. However to date, microRNAs that regulate hematopoietic stem cell (HSC) function have been less well characterized. Here we show that microRNA-125b (miR-125b) is highly expressed in HSCs and its expression decreases in committed progenitors. Overexpression of ...

Fluorescence techniques have been used to investigate the interaction of bovine 70-kDa heat shock cognate protein (Hsc 70) with small molecular weight peptides and myo-inositol monophosphatase. The emission properties of Hsc 70 remain invariant upon addition of ATP. The results of steady-state fluorescence indicate that the tryptophan residues of Hsc 70 are exposed to the rapidly relaxing aqueo...

Hepatic stellate cells (HSCs) play an important role in liver fibrosis. This study investigates the expression of hedgehog in HSC and the role of hedgehog signaling on activation and collagen secretion of HSC. Liver ex vivo perfusion with collagenase IV and density gradient centrifugation were used to isolate HSC. Expression of hedgehog signaling components Ihh, Smo, Ptc, Gli2 and Gli3 in HSC w...

We have previously shown that targeting human CD34(+) hematopoietic stem cells (HSC) with a bispecific antibody (BiAb) directed against myosin light chain (MLC) increases delivery of cells to the injured hearts and improves cardiac performance in the nude rat. In this study, we have sought to validate our previous observations and to perform more detailed determination of ventricular function i...

BACKGROUND C5a and its cognate receptor, C5a receptor (C5aR), key elements of complement, are critical modulators of liver immunity and fibrosis. However, the molecular mechanism for the cross talk between complement and liver fibrosis is not well understood. C5a is a potent chemokine regulating migration of cells in the innate immune system. Since activation and migration of hepatic stellate c...

All hematopoiesis cells develop from multipotent progenitor cells. Hematopoietic stem cells (HSC) have the ability to develop into all blood lineages but also maintain their stemness. Different molecular mechanisms have been identified that are crucial for regulating quiescence and self-renewal to maintain the stem cell pool and for inducing proliferation and lineage differentiation. The stem c...

Hepatic stellate cells (HSC) are located in the space of Disse in close contact with hepatocytes and sinusoidal endothelial cells. In human liver, HSC are located along the sinusoids with a nucleus-to-nucleus distance of 40 μm, indicating that the sinusoids are equipped with HSC at certain fixed distances1. These observations suggest that, although the total number of HSC constitutes a small pe...

The capacity of hematopoietic stem cells (HSC) to generate B lymphocytes declines with age, contributing to impaired immune function in the elderly. Here we show that the histone methyltransferase SUV39H1 plays an important role in human B lymphoid differentiation and that expression of SUV39H1 decreases with age in both human and mouse HSC, leading to a global reduction in H3K9 trimethylation ...

Formation of the hematopoietic stem cell (HSC) niche in bone marrow (BM) is tightly associated with endochondral ossification, but little is known about the mechanisms involved. We used the oc/oc mouse, a mouse model with impaired endochondral ossification caused by a loss of osteoclast (OCL) activity, to investigate the role of osteoblasts (OBLs) and OCLs in the HSC niche formation. The absenc...

The AP-1 transcription factor JunB is a transcriptional regulator of myelopoiesis. Inactivation of JunB in postnatal mice results in a myeloproliferative disorder (MPD) resembling early human chronic myelogenous leukemia (CML). Here, we show that JunB regulates the numbers of hematopoietic stem cells (HSC). JunB overexpression decreases the frequency of long-term HSC (LT-HSC), while JunB inacti...