TRPC1 and Orai1 interact with STIM1 and mediate capacitative Ca(2+) entry caused by acute hypoxia in mouse pulmonary arterial smooth muscle cells.

Previous studies in pulmonary artery smooth muscle cells (PASMCs) showed that acute hypoxia activates capacitative Ca(2+) entry (CCE) but the molecular candidate(s) mediating CCE caused by acute hypoxia remain unclear. The present study aimed to determine if transient receptor potential canonical 1 (TRPC1) and Orai1 interact with stromal interacting molecule 1 (STIM1) and mediate CCE caused by acute hypoxia in mouse PASMCs. In primary cultured PASMCs loaded with fura-2, acute hypoxia caused a transient followed by a sustained rise in intracellular Ca(2+) concentration ([Ca(2+)](i)).

Orai1 interacts with STIM1 and mediates capacitative Ca2+ entry in mouse pulmonary arterial smooth muscle cells.

Previous studies in mouse pulmonary arterial smooth muscle cells (PASMCs) showed that cannonical transient receptor potential channel TRPC1 and stromal interaction molecule 1 (STIM1) mediate the sustained component of capacitative Ca(2+) entry (CCE), but the molecular candidate(s) that mediate the transient component of CCE remain unknown. The aim of the present study was to examine whether Orai1 mediates the transient component of CCE through activation of STIM1 in mouse PASMCs. In primary cultured mouse PASMCs loaded with fura-2, cyclopiazonic acid (CPA) caused a transient followed by a sustained rise in intracellular Ca(2+) concentration ([Ca(2+)](i)).

The contribution of TRPC1 and STIM1 to capacitative Ca(2+) entry in pulmonary artery.

Capacitative calcium entry (CCE) through store-operated channels (SOCs) has been shown to contribute to the rise in intracellular calcium concentration ([Ca(2+)](i)) and mediate pulmonary artery smooth muscle contraction. CCE is activated as a result of depletion of intracellular Ca(2+) stores but there is a great deal of controversy surrounding the underlying signal that active CCE and the molecular makeup of SOCs. The discovery of canonical subgroup of transient receptor potential channels (TRPC) and recent identification of stromal-interacting molecule 1 (STIM1) protein have opened a door to the study of the identity of SOCs and the signal that activates these channels.

Generation of tissue-specific cells from MSC does not require fusion or donor-to-host mitochondrial/membrane transfer.

Human mesenchymal stem cells (MSC) hold great promise for cellular replacement therapies. Despite their contributing to phenotypically distinct cells in multiple tissues, controversy remains regarding whether the phenotype switch results from a true differentiation process. Here, we studied the events occurring during the first 120 h after human MSC transplantation into a large animal model.

TRPC1 and STIM1 mediate capacitative Ca2+ entry in mouse pulmonary arterial smooth muscle cells.

Previous studies in pulmonary arterial smooth muscle cells (PASMCs) showed that the TRPC1 channel mediates capacitative Ca(2+) entry (CCE), but the molecular signal(s) that activate TRPC1 in PASMCs remains unknown. The aim of the present study was to determine if TRPC1 mediates CCE through activation of STIM1 protein in mouse PASMCs. In primary cultured mouse PASMCs loaded with fura-2, cyclopiazonic acid (CPA) caused a transient followed by a sustained rise in intracellular Ca(2+) concentration ([Ca(2+)](i)).

Divergent mechanisms in generating molecular variations of alphaRYR and betaRYR in turkey skeletal muscle.

(1) Molecular variations in two turkey skeletal muscle ryanodine receptor gene isoforms, alphaRYR and betaRYR, were analyzed by cloning and sequencing the entire cDNAs of the two isoforms. (2) Ten alternative splicing transcript variants (ASTVs) in the alphaRYR isoform were identified. These variants were clustered in three alternative splicing regions (ASRs).

The time course of engraftment of human mesenchymal stem cells in fetal heart demonstrates that Purkinje fiber aggregates derive from a single cell and not multi-cell homing.

Objective: To study the early time course of engraftment of human mesenchymal stem cells in fetal sheep heart and determine the relative roles of proliferation and homing in formation of aggregates of human Purkinje fiber cells.

Methods: The human sheep xenograft model was utilized for these studies. Prior to injection in the preimmune fetus, human cells were labeled with fluorescent dyes to be able to track human cells at early times of engraftment.

A new human somatic stem cell from placental cord blood with intrinsic pluripotent differentiation potential.

Here a new, intrinsically pluripotent, CD45-negative population from human cord blood, termed unrestricted somatic stem cells (USSCs) is described. This rare population grows adherently and can be expanded to 10(15) cells without losing pluripotency. In vitro USSCs showed homogeneous differentiation into osteoblasts, chondroblasts, adipocytes, and hematopoietic and neural cells including astrocytes and neurons that express neurofilament, sodium channel protein, and various neurotransmitter phenotypes.

Human mesenchymal stem cells form Purkinje fibers in fetal sheep heart.

Background: We have investigated the usefulness of a model of cardiac development in a large mammal, sheep, for studies of engraftment of human stem cells in the heart.

Methods And Results: Adult and fetal human mesenchymal stem cells were injected intraperitoneally into sheep fetuses in utero. Hearts at late fetal development were analyzed for engraftment of human cells.