The Iron Regulatory Peptide Hepcidin Is Expressed in the Heart and Regulated by Hypoxia and Inflammation

Hepcidin, the Fe-regulatory peptide, has been shown to inhibit Fe absorption and reticuloendothelial Fe recycling. The present study was conducted to explore the mechanism of in vivo Fe regulation through genetic disruption of hepcidin1 and acute effects of hepcidin treatment in hepcidin1 knockout (Hepc1− / − ) and heterozygous mice. Hepcidin1 disruption resulted in significantly increased intestinal Fe uptake. Hepcidin injection inhibited Fe absorption in both genotypes, but the effects were more evident in the knockout mice. Hepcidin administration was also associated with decreased membrane localisation of ferroportin in the duodenum, liver and, most significantly, in the spleen of Hepc1− / − mice. Hypoferraemia was induced in heterozygous mice by hepcidin treatment, but not in Hepc1− / − mice, 4 h after injection. Interestingly, Fe absorption and serum Fe levels in Hepc1− / − and heterozygous mice fed a low-Fe diet were not affected by hepcidin injection. The present study demonstrates that hepcidin deficiency causes increased Fe absorption. The effects of hepcidin were abolished by dietary Fe deficiency, indicating that the response to hepcidin may be influenced by dietary Fe level or Fe status.

Download Full-text

Peptidomic Identification and Biological Validation of Neuroendocrine Regulatory Peptide-1 and -2

Journal of Biological Chemistry ◽

10.1074/jbc.m701665200 ◽

2007 ◽

Vol 282 (36) ◽

pp. 26354-26360 ◽

Cited By ~ 69

Author(s):

Hideki Yamaguchi ◽

Kazuki Sasaki ◽

Yoshinori Satomi ◽

Takuya Shimbara ◽

Haruaki Kageyama ◽

...

Keyword(s):

Regulatory Peptide ◽

Biological Validation

Download Full-text

Neuroendocrine Regulatory Peptide-2 Regulates Feeding Behavior Via the Orexin System in the Hypothalamus

10.1210/endo-meetings.2011.part2.p34.p2-290 ◽

2011 ◽

pp. P2-290-P2-290

Author(s):

Takashi Matsuo ◽

Koji Toshinai ◽

Haruaki Kageyama ◽

Hideki Yamaguchi ◽

Kazuki Sasaki ◽

...

Keyword(s):

Feeding Behavior ◽

Regulatory Peptide

Download Full-text

Regulatory peptide receptors: Visualization by autoradiography

Experientia Supplementum - Regulatory Peptides ◽

10.1007/978-3-0348-9136-3_5 ◽

1989 ◽

pp. 70-97 ◽

Cited By ~ 6

Author(s):

J. M. Palacios ◽

M. M. Dietl

Keyword(s):

Regulatory Peptide ◽

Peptide Receptors

Download Full-text

Upregulation of the angiogenic factor heparin affin regulatory peptide by progesterone in rat uterus

Journal of Endocrinology ◽

10.1677/joe.0.1580389 ◽

1998 ◽

Vol 158 (3) ◽

pp. 389-399 ◽

Cited By ~ 13

Author(s):

PE Milhiet ◽

F Vacherot ◽

JP Caruelle ◽

D Barritault ◽

D Caruelle ◽

...

Keyword(s):

Mrna Expression ◽

Hormonal Regulation ◽

Angiogenic Factor ◽

Mrna Levels ◽

Heparin Binding ◽

Regulatory Peptide ◽

Rat Uterus ◽

New Family ◽

Immunohistochemical Studies

Heparin affin regulatory peptide (HARP), also named pleiotropin, is a secreted polypeptide that belongs to a new family of heparin-binding growth/differentiation factors. In this study, we investigated the expression and distribution of HARP mRNA and protein in rat uterus. Semi-quantitative reverse transcriptase PCR experiments showed variations in HARP mRNA levels throughout the estrous cycle, with a maximum during diestrus, pointing to hormonal regulation of HARP mRNA expression. Uterine expression of HARP mRNA was studied in ovariectomized animals treated with 17 beta-estradiol, progesterone alone or progesterone and RU486. In these experiments, progesterone upregulated HARP mRNA expression. Induction was observed 6 h after progesterone injection and was inhibited by RU486 treatment. In contrast, after 17 beta-estradiol injection, a slight decrease in HARP mRNA expression was observed. In situ hybridization studies with digoxigenin-labeled DNA probe revealed that HARP mRNA was present in smooth muscle cells of both myometrium and blood vessels and also in endothelial cells from endometrium. Immunohistochemical studies showed that HARP expression was not limited to cells that expressed HARP mRNA, but also occurred in both the luminal and glandular epithelium even though its transcript was never detected. We conclude that HARP may mediate the effects of progesterone on the homeostasis and vascularization of uterine tissue.

Download Full-text

Receptor kinase complex transmits RALF peptide signal to inhibit root growth inArabidopsis

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1609626113 ◽

2016 ◽

Vol 113 (51) ◽

pp. E8326-E8334 ◽

Cited By ~ 58

Author(s):

Changqing Du ◽

Xiushan Li ◽

Jia Chen ◽

Weijun Chen ◽

Bin Li ◽

...

Keyword(s):

Control Plant ◽

Dependent Manner ◽

Receptor Complex ◽

Receptor Kinase ◽

Regulatory Peptide ◽

Signaling Mechanism ◽

Rhizosphere Acidification ◽

Receptor Like Kinase ◽

Inhibit Root Growth ◽

Rapid Alkalinization Factor

A number of hormones work together to control plant cell growth. Rapid Alkalinization Factor 1 (RALF1), a plant-derived small regulatory peptide, inhibits cell elongation through suppression of rhizosphere acidification in plants. Although a receptor-like kinase, FERONIA (FER), has been shown to act as a receptor for RALF1, the signaling mechanism remains unknown. In this study, we identified a receptor-like cytoplasmic kinase (RPM1-induced protein kinase, RIPK), a plasma membrane-associated member of the RLCK-VII subfamily, that is recruited to the receptor complex through interacting with FER in response to RALF1. RALF1 triggers the phosphorylation of both FER and RIPK in a mutually dependent manner. Genetic analysis of thefer-4andripkmutants reveals RIPK, as well as FER, to be required for RALF1 response in roots. The RALF1–FER–RIPK interactions may thus represent a mechanism for peptide signaling in plants.

Download Full-text