Endothelial cells (ECs) form a tight barrier to prevent vascular leakage. Although several studies reported that vascular leakage is increased during hypoxic conditions, other studies describe a protective effect. This raises the question how hypoxia specifically regulates adherens junction integrity and thus endothelial barrier function. Here, we investigated how hypoxia and the hypoxia-mimeti...

Chronic hypoxia reduces aerobic capacity (mitochondrial content) in limb skeletal muscles, and one of the causes seems to be decreased physical activity. Diaphragm and other respiratory muscles, however, may have a different pattern of adaptation as hypoxia increases the work of breathing. Thus, we hypothesized that chronic hypoxia would not reduce mitochondrial content in mouse diaphragm. Adul...

Apelin is the endogenous ligand for the APJ receptor, and apelin and APJ are expressed in the gastrointestinal (GI) tract. Intestinal inflammation increases intestinal hypoxia-inducible factor (HIF) and apelin expression. Hypoxia and inflammation are closely linked cellular insults. The purpose of these studies was to investigate the influence of hypoxia on enteric apelin expression. Exposure o...

The oxygen sensitive -subunit of the hypoxia-inducible factor-1 (HIF-1) is a major trigger of the cellular response to hypoxia. Although the posttranslational regulation of HIF-1 by hypoxia is well known, its transcriptional regulation by hypoxia is still under debate. We, therefore, investigated the regulation of HIF-1 mRNA in response to hypoxia in pulmonary artery smooth muscle cells. Hypoxi...

BACKGROUND Hypoxia-induced pulmonary hypertension is a major cause of morbidity and mortality. Hypoxia induces pulmonary vasoconstriction, in part, by decreasing endothelial nitric oxide synthase (eNOS) expression. The mechanism by which hypoxia decreases eNOS expression is not known but may involve Rho-kinase-induced actin cytoskeletal changes in vascular endothelial cells. METHODS AND RESUL...

Arousal is an important survival mechanism when infants are confronted with hypoxia during sleep. Many sudden infant death syndrome (SIDS) infants are exposed to repeated episodes of hypoxia before death and have impaired arousal mechanisms. We hypothesized that repeated exposures to hypoxia would cause a progressive blunting of arousal, and that a reversal of this process would occur if the hy...

Glioblastoma multiforme (GBM) tumors are the most common type of brain tumors and resistance to radiotherapy. This study aimed to investigate the differential effect and mechanism of tumor microenvironments, cycling hypoxia and non-interrupted hypoxia, on tumor cell radiosensitivity in the human U87 glioblastoma tumor model. We exposed U87 cells and mice bearing U87 glioma to experimentally imp...

Hypoxia and inflammatory cytokine activation (H&I) are common processes in many acute and chronic diseases. Thus, a single vector that responds to both hypoxia and inflammatory cytokines, such as TNF-α, is useful for assesing the severity of such diseases. Adaptation to hypoxia is regulated primarily by hypoxia inducible transcription factor (HIFα) nuclear proteins that engage genes containing ...

Hypoxia and increased extracellular nucleotides are frequently coincident in the brainstem. Extracellular nucleotides are potent modulators of microglial inflammatory gene expression via P2X purinergic receptor activation. Although hypoxia is also known to modulate inflammatory gene expression, little is known about how hypoxia or P2X receptor activation alone affect inflammatory molecule produ...

Hypoxia plays a critical role in coordinating cell survival, differentiation and death in normal embryogenesis; during limb pattern formation, hypoxia affects two key processes, chondrogenesis and cell death. Hypoxia promotes chondrocyte differentiation and cartilage matrix synthesis and suppresses terminal differentiation. Depending on the context, hypoxia may induce cell cycle arrest, pro- or...