Regulation of Erythropoiesis by Stimulators and Inhibitors

Regulation of erythropoiesis by hypoxia-inducible factors.

A classic physiologic response to systemic hypoxia is the increase in red blood cell production. Hypoxia-inducible factors (HIFs) orchestrate this response by inducing cell-type specific gene expression changes that result in increased erythropoietin (EPO) production in kidney and liver, in enhanced iron uptake and utilization and in adjustments of the bone marrow microenvironment that facilita...

Identification of stimulators and inhibitors of Cdc7 kinase in vitro.

Cdc7 is a serine-threonine kinase that regulates initiation and progression of DNA replication. The activity of purified Cdc7 kinase is significantly stimulated by polyamines such as spermine or spermidine. Positively charged polymers of lysine or arginine also stimulate its kinase activity, whereas the negatively charged substances such as polyglutamate or nucleic acids significantly inhibit t...

Stimulators and inhibitors of hepatic porphyrin formation in human sera.

Human sera were found to contain factors that stimulate and factors that inhibit porphyrin formation by cultured avian liver cells. The capacity of sera to stimulate or inhibit porphyrin formation varied in different hormonal states and in the porphyrias. Sera from 31 post partum women, eight of whom were not lactating, inhibited porphyrin formation to a mean level 30% below the level in contro...

Regulation of erythropoiesis.

RED CELLS, IRON, AND ERYTHROPOIESIS Regulation of murine normal and stress-induced erythropoiesis by Desert Hedgehog

The function of Hedgehog signaling in hematopoiesis is controversial, with different experimental systems giving opposing results. Here we examined the role of Desert Hedgehog (Dhh) in the regulation of murine erythropoiesis. Dhh is one of 3 mammalian Hedgehog family proteins. Dhh is essential for testis development and Schwann cell function. We show, by analysis of Dhh-deficient mice, that Dhh...