(C) 2009 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.”
“Mesenchymal stem cells (MSCs) have an inhibitory effect on tumor proliferation, but the precise mechanisms are not fully understood. Here, we identified DKK-1 (dickkopf-1), secreted by MSCs and acting as a negative regulator of WNT signaling pathway, www.selleckchem.com/products/PD-173074.html to be one of the molecules responsible for the inhibitory effect. When DKK-1 was neutralized by anti-DKK-1 antibodies, or when the expression of DKK-1 was downregulated by RNA interference (RNAi), the inhibitory effects of MSCs on K562 cell proliferation
were attenuated. We also provide evidence that the expression of DKK-1 by MSCs is regulated by NANOG, a transcriptional factor ubiquitously expressed in some stem cells. Using the Cellmax artificial capillary modules that eliminate the immunosuppressive properties of MSCs, we further showed that MSCs were able to inhibit proliferation of K562 cells in a humoral microenvironment. Meanwhile, www.selleckchem.com/products/AG-014699.html we recapture this effect of MSCs on primary leukemic hematopoietic progenitors from patients. MSCs probably have a general inhibitory effect on their neighboring cells,
including malignant cells, en route to achieving tissue homeostasis. Leukemia (2009) 23, 925-933; doi:10.1038/leu.2008.384; published online 15 January 2009″
“Secreted mammalian Ly6/urokinase plasminogen activator receptor-related protein-1 (SLURP-1) is a recently identified,
endogenous ligand Bcl-w of the alpha 7 subunit of nicotinic acetylcholine receptors. SLURP-1 is also the causative gene for an autosomal recessive palmoplantar keratoderma, Mal de Meleda. Although the function of SLURP-1 in keratinocyte development and differentiation has been extensively studied, little is known about its role in the nervous system. In the present study, we analyzed SLURP-1 expression in the spinal cord of rats, as a number of studies suggest spinal nicotinic acetylcholine receptors are important modulators of pain transmission. We detected intense SLURP-1 immunoreactivity in the dorsal horn of the spinal cord, especially in lamina I and outer II. In dorsal root ganglia, SLURP-1 immunoreactivity was detected in small- to medium-sized neurons, where in situ hybridization also revealed the presence of SLURP-1 mRNA. Fluorescent labeling of SLURP-1 partially overlapped that of calcitonin-gene related peptide (CGRP) or substance P (SP) in both the spinal cord dorsal horn and glabrous skin, and electron microscopic analysis revealed colocalization of SLURP-1 with SP or CGRP, in large synaptic vesicles in terminals within the superficial layer of the spinal cord. Finally, sciatic nerve axotomy reduced levels of SLURP-1 immunoreactivity in parallel with that of SP and CGRP in the ipsilateral superficial dorsal horn. These findings suggest that SLURP-1 is expressed in a subset of primary peptidergic sensory neurons.