University of Tsukuba

About: University of Tsukuba is a education organization based out in Tsukuba, Ibaraki, Japan. It is known for research contribution in the topics: Population & Gene. The organization has 36352 authors who have published 79483 publications receiving 1934752 citations. The organization is also known as: Tsukuba daigaku & Tsukuba University.

Role of JNK, p38, and ERK in Platelet-Derived Growth Factor–Induced Vascular Proliferation, Migration, and Gene Expression

Abstract: Objective— We investigated the comparative roles of mitogen-activated protein (MAP) kinases, including c-Jun NH2-terminal kinase (JNK), extracellular signal-regulated kinase (ERK), and p38, in vascular smooth muscle cell (VSMC) proliferation, migration, and gene expression. Methods and Results— VSMCs were infected with recombinant adenovirus containing dominant-negative mutants of ERK, p38, and JNK (Ad-DN-ERK, Ad-DN-p38, and Ad-DN-JNK, respectively) to specifically inhibit the respective MAP kinases and then stimulated with platelet-derived growth factor (PDGF)-BB. Ad-DN-ERK attenuated PDGF-BB–induced VSMC proliferation more potently than Ad-DN-p38 or Ad-DN-JNK, indicating the dominant role of ERK in VSMC proliferation. Ad-DN-ERK, Ad-DN-p38, and Ad-DN-JNK similarly inhibited PDGF-induced VSMC migration. Ad-DN-ERK and Ad-DN-JNK suppressed PDGF-BB–induced downregulation of cyclin-dependent kinase inhibitor p27Kip1, whereas Ad-DN-p38 decreased PDGF-BB–induced upregulation of p21Cip1. Ad-DN-ERK inhibited PDGF...

Endothelin: A novel peptide in the posterior pituitary system

Abstract: Endothelin (ET), originally characterized as a 21-residue vasoconstrictor peptide from endothelial cells, is present in the porcine spinal cord and may act as a neuropeptide. Endothelin-like immunoreactivity has now been demonstrated by immunohistochemistry in the paraventricular and supraoptic nuclear neurons and their terminals in the posterior pituitary of the pig and the rat. The presence of ET in the porcine hypothalamus was confirmed by reversed-phase high-pressure liquid chromatography and radioimmunoassay. Moreover, in situ hybridization demonstrated ET messenger RNA in porcine paraventricular nuclear neurons. Endothelin-like immunoreactive products in the posterior pituitary of the rat were depleted by water deprivation, suggesting a release of ET under physiological conditions. These findings indicate that ET is synthesized in the posterior pituitary system and may be involved in neurosecretory functions.

Essential role of the posterior morphogen nanos for germline development in Drosophila

Abstract: IN many animal groups, factors required for germline formation are localized in germ plasm1, a region of the egg cytoplasm. In Drosophila embryos, germ plasm is located in the posterior pole region and is inherited in pole cells, the germline progenitors. Transplantation experiments have demonstrated that germ plasm contains factors that can form germline2–4, and germ plasm also directs abdomen formation5. Genetic analysis has shown that a common mechanism directs the localization of the abdomen and germline-forming factors to the posterior pole6–12. The critical factor for abdomen formation is the nanos (nos) protein (nanos)13–15. Here we show that nos is also essential for germline formation in Drosophila; pole cells lacking nanos activity fail to migrate into the gonads, and so do not become functional germ cells. In such pole cells, gene expression, which normally initiates within the gonad, begins prematurely during pole-cell migration. Premature activation of genes in germline precursors may mean that these cells fail to develop normally. A function for nos protein in Drosophila germline formation is compatible with observations of its association with germ plasm in other animals16–18.