Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P20366 (substance P)
 21,176 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The neuropeptide Substance P (SP) is widely distributed in the peripheral nervous system. Its biologic effects have been extensively studied in the immune system. However, even though the bone marrow (BM) is innervated with SP-immunoreactive fibers and some of its cells not only express SP receptors (T and B cells, endothelial cells, and macrophages) but also produce SP (macrophages, eosinophils, and endothelial cells), the effects of SP on hematopoiesis are scanty. Furthermore, SP induces the production of hematopoietic growth factors (HGFs) (interleukin-1 [IL-1], IL-6, and tumor necrosis factor alpha) from human monocytes. In this study, we have found a potent in vitro stimulatory effect of SP (10(-8) to 10(-12) mol/L) on hematopoiesis for both erythroid and granulocytic progenitors in short-term methyl-cellulose BM cultures. SP alone, in the absence of exogenous HGFs, is able to sustain hematopoiesis in vitro. This stimulatory effect of SP is: (1) mostly mediated by the adherent cells; (2) completely abrogated by two SP receptor (SP-R) antagonists; and (3) partially reduced by anti-IL-1, IL-3, IL-6, and granulocyte-macrophage colony-stimulating factor (GM-CSF). Furthermore, it appears that the stimulatory effect of SP may be mediated by IL-3 and GM-CSF because we have also found that SP induces the release of these two cytokines from BM mononuclear cells. Considering that the SP effect occurs at concentrations as low as 10(-11) mol/L, and via a specific receptor, it appears that SP may play a physiologic role in regulating hematopoiesis, at least partially through the adherent BM cells and the release of HGFs, and may place SP, a neuropeptide, in a new category of hematopoietic regulators.
 ...
PMID:In vitro stimulatory effect of substance P on hematopoiesis. 767 16

The tachykinins are a family of neuropeptides that share a common carboxyl terminus. Substance P (SP) and neurokinin-A (NK-A) are derived from the preprotachykinin l gene. Although SP and NK-A can bind to either NK-1, NK-2, or NK-3 receptors (R), they have preferences for NK-1R and NK-2R, respectively. We have reported that SP stimulates erythroid (E) (burst-forming unit [BFU]-E and colony-forming unit [CFU]-E) and myeloid (CFU-granulocyte-macrophage [GM]) progenitors partly through the induction of growth factors. We have now investigated the hematopoietic effects of NK-A using short-term bone marrow (BM) cultures and found that NK-A (10(-7) to 10(-12) mol/L) inhibits CFU-GM proliferation but stimulates erythroid progenitors. Release of soluble factors by the stroma appears to mediate the inhibition because direct contact with the stroma was not required. We have found that NK-A, through NK-2-like receptors induces increased levels of macrophage inflammatory protein-1 alpha (MIP-1 alpha) and transforming growth factor-beta (TGF-beta) (transcriptional and posttranscriptional) in BM stroma. Clonogenic assays with NK-A (10(-9) mol/L) and either anti-MIP-1 alpha or anti-TGF- beta 1 indicate that these cytokines partly contribute to the inhibition, suggesting that these two negative hematopoietic regulators exert part of the inhibition by NK-A on CFU-GM. The findings of two closely related neuropeptides, derived from the same gene, exerting opposite effects on myeloid colonies suggest that neuropeptides, by themselves could be important factors in hematopoietic regulation.
 ...
PMID:Induction of negative hematopoietic regulators by neurokinin-A in bone marrow stroma. 870 7

The Kell blood group is a highly polymorphic system containing over 20 different antigens borne by the protein Kell, a 93-kDa type II glycoprotein that displays high sequence homology with members of the M13 family of zinc-dependent metalloproteases whose prototypical member is neprilysin. Kell K1 is an antigen expressed in 9% of the Caucasian population, characterized by a point mutation (T193M) of the Kell K2 antigen, and located within a putative N-glycosylation consensus sequence. Recently, a recombinant, non-physiological, soluble form of Kell was shown to cleave Big ET-3 to produce the mature vasoconstrictive peptide. To better characterize the enzymatic activity of the Kell protein and the possible differences introduced by antigenic point mutations affecting post-translational processing, the membrane-bound forms of the Kell K1 and Kell K2 antigens were expressed either in K562 cells, an erythroid cell line, or in HEK293 cells, a non-erythroid system, and their pharmacological profiles and enzymatic specificities toward synthetic and natural peptides were evaluated. Results presented herein reveal that the two antigens possess considerable differences in their enzymatic activities, although not in their trafficking pattern. Indeed, although both antigens are expressed at the cell surface, Kell K1 protein is shown to be inactive, whereas the Kell K2 antigen binds neprilysin inhibitory compounds such as phosphoramidon and thiorphan with high affinity, cleaves the precursors of the endothelin peptides, and inactivates members of the tachykinin family with enzymatic properties resembling those of other members of the M13 family of metalloproteases to which it belongs.
 ...
PMID:The Kell protein of the common K2 phenotype is a catalytically active metalloprotease, whereas the rare Kell K1 antigen is inactive. Identification of novel substrates for the Kell protein. 1576 48

Regulation of normal hematopoiesis by neuropeptide substance P (SP) and its amino terminal fragment, SP(1-4), has been reported. Endogenous erythroid colony (EEC) formation without erythropoietin is characteristic of polycythemia vera (PV), a chronic myeloproliferative disorder. We investigated the effect(s) of SP and SP(1-4) on EEC formation from PV BM mononuclear cells (BMMCs) and purified CD36+ erythroid progenitors. We found a potent in vitro inhibitory effect of SP and SP(1-4) on PV EEC formation for both BMMCs and CD36+ erythroid progenitors. The influence of SP and SP(1-4) on PV progenitor erythroid differentiation and cell viability was also investigated, and the impact of neurokinin receptors and G proteins in the inhibition were analyzed by quantitative PCR and with specific inhibitors. This progenitor inhibition was: (1) not mediated by accessory cells; (2) characterized by an increase in cell death and inhibition of the EPOindependent terminal erythroid differentiation; and (3) not mediated by the same neurokinin receptor. NK-1R and NK-2R antagonists completely abrogated the SP inhibitory effect but not SP(1-4)-induced inhibition. Furthermore, the truncated form of the NK-1R was predominant over the full-length mRNA and could mediated the SP inhibitory effect on PV CD36+ erythroid progenitors. Different G proteins were also implicated according to the erythroid differentiation stage of the PV cells. The observation of an inhibitory effect of SP and its related peptide, SP(1-4), on PV EEC formation at physiological concentrations (10-8M) suggests that neuropeptides represent a way to downregulate pathologic expansion of PV progenitors.
 ...
PMID:Inhibitory effect of the substance P and its derivative on erythropoietin-independent growth of erythroid progenitors in polycythemia vera. 1798 Apr 27

There is little evidence on roles of growth factors other than cytokines in expansion of cord blood (CB) stem cells. We aimed to explore a novel approach for expansion, using Substance P (SP) and calcitonin gene-related peptide (CGRP) neuropeptides. CB CD34(+) cells were cultured in different concentrations of SP and/or CGRP in combination with a cytokine cocktail. Phenotypic and functional analysis was performed by flowcytometry and colonogenic assay. Our results show a significant improvement of total expansion of neuropeptide treated cells. There was a selective effect of CGRP on CD34(+) CD133(+) cells, SP on CD34(+) CD45(dim) cells, and 10(- 9) M SP and/or CGRP on expansion of CD34(+) CD38(- ) cells. There was also a tendency for erythroid and granulocyte-myeloid colony formation in SP and CGRP treated cultures, respectively. Supplementation of cytokines with other growth factors, such as neuropeptides, might enable us to overcome the difficulties of ex vivo expansion of CB cells.
 ...
PMID:Substance P and calcitonin gene-related neuropeptides as novel growth factors for ex vivo expansion of cord blood CD34(+) hematopoietic stem cells. 1990 13